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Tytuł:
Theoretical Studies of the Local Structures and EPR Spectra for $VO^{2+}$ in $MB_4O_7$ (M = Zn, Cd) Glasses
Autorzy:
Li, C.
Zheng, X.
Powiązania:
https://bibliotekanauki.pl/articles/1206562.pdf
Data publikacji:
2014-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
76.30.Fc
Opis:
Electron spin resonance spectral parameters (g factors $g_{∥}$, $g_{⊥}$ and hyperfine structure constants $A_{∥}$, $A_{⊥}$) of a tetragonal $V^{4+}$ centers in $MB_4O_7$ (M = Zn, Cd) are theoretically investigated by using the perturbation formulae for a $3 d^1$ ion in tetragonally compressed octahedra. In these formulae, the contributions to the g factors from the tetragonal distortion, characterized by the tetragonal field parameters $D_{s}$ and $D_{t}$ are taken into account by considering the local structures of the ligand octahedron around the $V^{4+}$ due to the Jahn-Teller effect. Based on the calculations, the ligand octahedra around $V^{4+}$ are suggested to suffer about 5.7% and 4.3% relative compression along $C_4$ axis for $MB_4O_7$ glasses with M = Zn and Cd, respectively, and negative signs of the hyperfine structure constants $A_{∥}$ and $A_{⊥}$ for $V^{4+}$ centers in $MB_4O_7$ glasses were suggested in the discussion.
Źródło:
Acta Physica Polonica A; 2014, 125, 1; 73-76
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Porous sets for mutually nearest points in Banach spaces
Autorzy:
Li, C.
Myjak, J
Powiązania:
https://bibliotekanauki.pl/articles/255091.pdf
Data publikacji:
2008
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
minimization problem
well-posedness
Hp-topology
porous set
Opis:
Let B(X) denote the family of all nonempty closed bounded subsets of a real Banach space X, endowed with the Hausdorff metric. For E, F ∈ B (X) we set [formula]. Let D denote the closure (under the maximum distance) of the set of all (E, F) ∈ B (X) x B (X) such that λE,F > 0. It is proved that the set of all (E, F) ∈ D for which the minimization problem [formula] fails to be well posed in a σ-porous subset of D.
Źródło:
Opuscula Mathematica; 2008, 28, 1; 73-82
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Intelligent financial time series forecasting: A complex neuro-fuzzy approach with multi-swarm intelligence
Autorzy:
Li, C.
Chiang, T. W.
Powiązania:
https://bibliotekanauki.pl/articles/331280.pdf
Data publikacji:
2012
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
zbiór rozmyty
system neuronowo-rozmyty
optymalizacja rojem cząstek
szereg czasowy
complex fuzzy set
complex neuro fuzzy system
hierarchical multi swarm
particle swarm optimization (PSO)
recursive least squares estimator
time series forecasting
Opis:
Financial investors often face an urgent need to predict the future. Accurate forecasting may allow investors to be aware of changes in financial markets in the future, so that they can reduce the risk of investment. In this paper, we present an intelligent computing paradigm, called the Complex Neuro-Fuzzy System (CNFS), applied to the problem of financial time series forecasting. The CNFS is an adaptive system, which is designed using Complex Fuzzy Sets (CFSs) whose membership functions are complex-valued and characterized within the unit disc of the complex plane. The application of CFSs to the CNFS can augment the adaptive capability of nonlinear functional mapping, which is valuable for nonlinear forecasting. Moreover, to optimize the CNFS for accurate forecasting, we devised a new hybrid learning method, called the HMSPSO-RLSE, which integrates in a hybrid way the so-called Hierarchical Multi-Swarm PSO (HMSPSO) and the well known Recursive Least Squares Estimator (RLSE). Three examples of financial time series are used to test the proposed approach, whose experimental results outperform those of other methods.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2012, 22, 4; 787-800
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dual manipulator system calibration based on virtual constraints
Autorzy:
Zhu, Q.
Xie, X.
Li, C.
Powiązania:
https://bibliotekanauki.pl/articles/200227.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
dual manipulators
calibration
virtual constraint
optical axis
robot-robot
hand-eye
Opis:
Calibration is necessary for dual manipulator to complete operational tasks. This paper proposes an effective robot-robot and hand-eye calibration method based on virtual constraints. Firstly, a rotational error model and a translational error model are established based on the relationships between the transformation matrices of the dual manipulator calibration system. Then a poses-alignment method is designed to make the poses of the two robots satisfy the constructed virtual constraints. At the aligned positions, the joint angles of the two robots are saved and used to calculate the values of the variables in the error models. Finally, the robot-robot and hand-eye rotational errors are estimated by an iterative algorithm. These errors are then used to calculate translational errors based on the SVD (singular value decomposition) method. To show the feasibility and effectiveness of the proposed method, experiments of robot-robot and hand-eye calibration for dual manipulators are performed. The experiment results demonstrate that the accuracy of the dual manipulator system is improved greatly.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2019, 67, 6; 1149-1159
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Robust aperiodic-disturbance rejection in an uncertain modified repetitive-control system
Autorzy:
Zhou, L.
She, J.
Li, C.
Pan, C.
Powiązania:
https://bibliotekanauki.pl/articles/330015.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
repetitive control
equivalent input disturbance
two dimensional system
singular value decomposition
linear matrix inequality
sterowanie powtarzalne
układ dwuwymiarowy
rozkład na wartości szczególne
liniowa nierówność macierzowa
Opis:
This paper concerns the problem of designing an EID-based robust output-feedback modified repetitive-control system (ROFMRCS) that provides satisfactory aperiodic-disturbance rejection performance for a class of plants with time-varying structured uncertainties. An equivalent-input-disturbance (EID) estimator is added to the ROFMRCS that estimates the influences of all types of disturbances and compensates them. A continuous-discrete two-dimensional model is built to describe the EID-based ROFMRCS that accurately presents the features of repetitive control, thereby enabling the control and learning actions to be preferentially adjusted. A robust stability condition for the closed-loop system is given in terms of a linear matrix inequality. It yields the parameters of the repetitive controller, the output-feedback controller, and the EID-estimator. Finally, a numerical example demonstrates the validity of the method.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2016, 26, 2; 285-295
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of 2D and 3D models of salinity numerical simulation
Autorzy:
Li, C.
Pan, X.
Ke, J.
Dong, X.
Powiązania:
https://bibliotekanauki.pl/articles/260550.pdf
Data publikacji:
2015
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
2D model
3D model
salty
strong brine
numerical simulation
Opis:
For the study of the effect of 2D and 3D mathematical model in salinity simulation, with Liuheng island strong brine discharge of seawater desalination project as an example, using 2D and 3D salinity mathematical models of Liuheng island to simulate coastal hydrodynamic environment and salinity distribution before and after the concentrated brine discharge, and analyzed the results. Finally got the applicable scope of the two models, it has an important significance in the study of similar problems.
Źródło:
Polish Maritime Research; 2015, S 1; 26-29
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of heating on thermal denaturation of several green vegetables suitable for dehydration
Autorzy:
Zhang, M.
Li, C.L.
Ding, X.L.
Powiązania:
https://bibliotekanauki.pl/articles/25723.pdf
Data publikacji:
2001
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
differential scanning calorimetry
dehydration
heating
thermal analysis
thermal denaturation
vegetable
green vegetable
Źródło:
International Agrophysics; 2001, 15, 3
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Process improvement and kinetic study on copper leaching from low-grade cuprite ores
Autorzy:
Bai, S.
Fu, X.
Li, C.
Wen, S.
Powiązania:
https://bibliotekanauki.pl/articles/109660.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
cuprite
dissolution kinetics
sulfuric acid leaching
SCM
Opis:
Process improvement and kinetic study on copper leaching from low-grade cuprite ores in sulfuric acid solution are presented in this paper. Effects of major leaching parameters on copper leaching efficiency are determined. The results indicate that copper minerals in the raw ores are mainly cuprites. The reaction rate of this ore increases with an increase in temperature, reaction time, sulfuric acid concentrations and decrease in the particle size of ore. Leaching of about 92.5% of copper is achieved using 0.125-0.074 mm ore particle size at a reaction temperature of 353 K for 180 min reaction time with 150 g/dm3 sulfuric acid. The solid/liquid ratio was maintained constant at 1:15. Leaching kinetic indicates experimental data complies with shrinking core mode (SCM). It is found in the study that agitation rate is not an influential factor on leaching rate and that the dissolution rate is controlled by surface chemical reaction. The average activation energy of the process is determined to be 45.28 kJ mol-1, and the reaction order of H2SO4 is 0.8093.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 2; 300-310
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synergism of octane phenol polyoxyethylene-10 and oleic acid in apatite flotation
Autorzy:
Cheng, R.
Li, C.
Liu, X.
Deng, S.
Powiązania:
https://bibliotekanauki.pl/articles/110793.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
octane phenol polyoxyethylene-10
synergistic effect
flotation
apatite
Opis:
The addition of octane phenol polyoxyethylene-10 (OP-10) to oleic acid via a reagent-combination technology was carried out and it was shown that OP-10 exhibited synergistic effects in the flotation performance of oleic acid. Single-mineral flotation tests, zeta-potential measurements, total-organic-carbon determination, and scale-up of continuous tests using raw ore were also carried out. Single-mineral flotation tests showed that OP-10 exhibited virtually no collecting performance for apatite, but it improved the flotation performance of oleic acid following its addition to oleic acid in small amounts at low temperature. Zeta-potential measurements and total-organic-carbon determination results indicated that the addition of 2.5% OP-10 to oleic acid increased the absolute value of the apatite surface potential and improved adsorption of oleic acid on the apatite surface at low temperature. A scale-up of the continuous test showed that application of OP-10 with industrial fatty acids led to good synergistic effects and contributed to effective separation of phosphate ore.
Źródło:
Physicochemical Problems of Mineral Processing; 2017, 53, 2; 1214-1227
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Observer-based leader-following formation control of uncertain multiple agents by integral sliding mode
Autorzy:
Qian, D. W.
Tong, S. W.
Li, C. D.
Powiązania:
https://bibliotekanauki.pl/articles/201511.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
multi-agent system
formation control
integral sliding mode control
uncertainty
nonlinear disturbance observer
stability
system wieloagentowy
kontrola formacji
integralne sterowanie ślizgowe
niepewność
nieliniowy obserwator zakłóceń
stabilność
Opis:
This paper investigates the formation control problem of multiple agents. The formation control is founded on leader-following approaches. The method of integral sliding mode control is adopted to achieve formation maneuvers of the agents based on the concept of graph theory. Since the agents are subject to uncertainties, the uncertainties also challenge the formation-control design. Under a mild assumption that the uncertainties have an unknown bound, the technique of nonlinear disturbance observer is utilized to tackle the issue. According to a given communication topology, formation stability conditions are investigated by the observer-based integral sliding mode formation control. From the perspective of Lyapunov, not only is the formation stability guaranteed, but the desired formation of the agents is also realized. Finally, some simulation results are presented to show the feasibility and validity of the proposed control scheme through a multi-agent platform.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2017, 65, 1; 35-44
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Restructuring of a zooplankton community by perturbation from a wind-forced coastal jet
Autorzy:
Pedersen, O.-P.
Tande, K.S.
Li, C.
Zhou, M.
Powiązania:
https://bibliotekanauki.pl/articles/47789.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
zooplankton
filament
intrusion
restructuring
mesoscale
perturbation
coastal region
Norway
transient wind
saline water
equivalent spherical diameter
Opis:
The impact of transient wind events on an established zooplankton community was observed during a field survey in a coastal region off northern Norway in May 2002. A transient wind event induced a coastal jet/filament intrusion of warm, saline water into our survey area where a semi-permanent eddy was present. There was an abrupt change in zooplankton community structure within 4–7 days of the wind event, with a change in the size structure, an increase in lower size classes less than 1 mm in equivalent spherical diameter (ESD) and a decrease in larger size classes greater than 1.5 mm in ESD. The slope of zooplankton biovolume spectra changed from −0.6 to −0.8, consistent with the size shifting towards smaller size classes. This study shows that even well established zooplankton communities are susceptible to restructuring during transient wind events, and in particular when wind forcing induces horizontal currents or filaments.
Źródło:
Oceanologia; 2010, 52, 3; 473-497
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electric Interaction between Two Identical Conducting Spheres in a Uniform Electric Field
Autorzy:
Gao, X.
Wang, Q.
Li, C.
Hu, L.
Sun, G.
Powiązania:
https://bibliotekanauki.pl/articles/1401870.pdf
Data publikacji:
2015-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
41.20.Cv
47.65.Gx
Opis:
An experimental apparatus is devised to measure the interaction between two spheres separated by a small gap in a uniform electric field. The results show that the interaction between two conducting spheres is near that between two dielectric spheres with high permittivity. Accordingly, the calculation can be simplified by mirror image method, for it is only available for conducting system. A method using multiple mirror images of point charges is put forward to analyze the induction of two identical conducting spheres in a uniform electric field. The key operation on how to add compensative charges is emphasized and given out in detail. The results from experiment and calculation are compared, and they agree with each other very well.
Źródło:
Acta Physica Polonica A; 2015, 128, 3; 289-293
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Efficient learning variable impedance control for industrial robots
Autorzy:
Li, C.
Zhang, Z.
Xia, G.
Xie, X.
Zhu, Q.
Powiązania:
https://bibliotekanauki.pl/articles/200716.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
variable impedance control
reinforcement learning
efficient
Gaussian process
industrial robots
impedancja
poprawa efektywności
wydajność
model Gaussa
roboty przemysłowe
Opis:
Compared with the robots, humans can learn to perform various contact tasks in unstructured environments by modulating arm impedance characteristics. In this article, we consider endowing this compliant ability to the industrial robots to effectively learn to perform repetitive force-sensitive tasks. Current learning impedance control methods usually suffer from inefficiency. This paper establishes an efficient variable impedance control method. To improve the learning efficiency, we employ the probabilistic Gaussian process model as the transition dynamics of the system for internal simulation, permitting long-term inference and planning in a Bayesian manner. Then, the optimal impedance regulation strategy is searched using a model-based reinforcement learning algorithm. The effectiveness and efficiency of the proposed method are verified through force control tasks using a 6-DoFs Reinovo industrial manipulator.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2019, 67, 2; 201-212
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Identifying Training Deficiencies in Military Pilots by Applying the Human Factors Analysis and Classification System
Autorzy:
Li, W. C.
Harris, D.
Powiązania:
https://bibliotekanauki.pl/articles/90259.pdf
Data publikacji:
2013
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
accident investigation
error analysis
human error
human factors analysis and classification system (HFACS)
training development
piloci samolotów
czynnik ludzki
klasyfikacja
przyczyny wypadków
wojsko
badanie wypadków
błędy ludzkie
trening
Opis:
Without accurate analysis, it is difficult to identify training needs and develop the content of training programs required for preventing aviation accidents. The human factors analysis and classification system (HFACS) is based on Reason's system-wide model of human error. In this study, 523 accidents from the Republic of China Air Force were analyzed in which 1762 human errors were categorized. The results of the analysis showed that errors of judgment and poor decision-making were commonly reported amongst pilots. As a result, it was concluded that there was a need for military pilots to be trained specifically in making decisions in tactical environments. However, application of HFACS also allowed the identification of systemic training deficiencies within the organization further contributing to the accidents observed.
Źródło:
International Journal of Occupational Safety and Ergonomics; 2013, 19, 1; 3-18
1080-3548
Pojawia się w:
International Journal of Occupational Safety and Ergonomics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of Cotton Matured Fibre Quality and the Super-Molecular Structure in Upland Cotton RILs
Analiza jakości dojrzałych włókien bawełny Upland i jej struktury nadcząsteczkowej
Autorzy:
Wang, Y.
Li, C
Shang, H
Li, B
Liu, A
Yuan, Y
Powiązania:
https://bibliotekanauki.pl/articles/231848.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
upland cotton
recombinant inbred lines
fibre super-molecular structure
fibre quality
dojrzałe włókna bawełny
bawełna Upland
zmodyfikowana genetycznie bawełna
cechy włókniste bawełny
super-molekularna struktura włókien
jakość włókna
Opis:
A RIL(recombinant inbred lines) population with 196 F6:9 lines was developed from an F2 population of upland cotton (Gossypium hirsutum L.) cross of sGK9708×0-153. sGK9708 is a commercial transgenic variety with Bt+CpTI genes resistant to budworm and 0-153 with high fibre quality. Five materials with high fibre strength and five materials with low fibre strength from the recombinant inbred lines were researched [1]. Ten materials of super-molecular structure and fibre quality were studied by X-ray diffraction and the HVI900 technique. The results indicated that cotton matured fibre quality should mainly depend on the decrease in the orientational parameter in the crystalline section, especially the orientational separate and orientational distribution angles. The correlation of fibre maturity, linear density and the fibre super-molecular structure is an innovation in the study. Studies on the correlation of cotton fibre quality and the fibre super-molecular structure provide a scientific basis for the improvement cotton fibre quality.
Artykuł dotyczy badań jakości dojrzałych włókien bawełny amerykańskiej Upland i jej struktury nadcząsteczkowej. Uzyskano zmodyfikowany genetycznie gatunek bawełny amerykańskiej Upland za pośrednictwem sztucznego samozapylenia bawełny wykazującej cechy włókniste (linii wsobnej). Dla uzyskanych w opisany sposób włókien bawełny przeprowadzono wszechstronne badania właściwości fizycznych, a także struktury nadcząsteczkowej. Uzyskane wyniki badań skonfrontowano z właściwościami fizycznymi i strukturą nadczasteczkową tradycyjnej bawełny amerykańskiej Upland posiłkując się w tym celu analizą korelacyjną.
Źródło:
Fibres & Textiles in Eastern Europe; 2014, 5 (107); 28-33
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Using an Interdigital Micromixer for Separation of In3+ from Zinc Hydrometallurgical Process with D2EHPA as an Extractant
Autorzy:
Li, C.
Jiang, F.
Ju, S.
Peng, J.
Wei, Y.
Zhang, L.
Powiązania:
https://bibliotekanauki.pl/articles/356090.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
interdigital micromixer
solvent extraction
mass transfer coefficient
indium
stripping
Opis:
Experiments were performed in an interdigital micromixer with 30 microchannels (40 μm width of each channel) to separate In3+, Fe3+ and Zn2+ from sulfate solutions using Di-(2-ethylhexyl)phosphoric acid (D2EHPA) as the extractant. The effects of pH, extractant concentration and flow rate on the extraction efficiency and flow rate on mass transfer coefficient of In3+, Fe3+ and Zn2+ were investigated. At a phase flow rate of 7.0 mL/min and initial solution pH of 0.423, the extraction efficiency of In3+, Fe3+ and Zn2+ was 99.29%, 3.43% and 2.54%, respectively and mass transfer coefficient of In3+, Fe3+ and Zn2+ was 144.307 s-1,1.018 s-1 and 0.750 s-1. Then, the loaded organic phase was stripped in an interdigital micromixer. At a phase flow rate of 9.0 mL/min and HCl concentration of 160 g/L, stripping efficiency of In3+ was 98.92% and mass transfer coefficient of In3+ was 169.808 s-1, while concentration of Fe3+ and Zn2+ was lower than 0.005 g/L with good separation of In3+ from Fe3+ and Zn2+.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 2A; 873-878
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Vacuum Hot-Press Process on The Sintered Characteristics and Mechanical Properties of A High-Density Cr-31.2 Mass% Ti Alloy
Autorzy:
Chang, S.-H.
Li, C.-L.
Huang, K.-T.
Yang, T.-H.
Powiązania:
https://bibliotekanauki.pl/articles/356911.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Cr-31.2 mass% Ti alloy
vacuum hot-press sintering
relative density
TRS
electrical conductivity
Opis:
In this study, two different compositions of submicron-structured titanium (760 nm) and micron-structured chromium (4.66 μm) powders were mixed to fabricate Cr-31.2 mass% Ti alloys by vacuum hot-press sintering. The research imposed various hot-press sintering pressures (20, 35 and 50 MPa), while the sintering temperature maintained at 1250°C for 1h. The experimental results showed that the optimum parameters of the hot-press sintered Cr-31.2 mass% Ti alloys were 1250°C at 50 MPa for 1h. Also, the relative density reached 99.94%, the closed porosity decreased to 0.04% and the hardness and transverse rupture strength (TRS) values increased to 81.90 HRA and 448.53 MPa, respectively. Moreover, the electrical conductivity is enhanced to 1.58 × 104 S·cm-1 However, the grain growth generated during the high-temperature and high-pressure of the hot-press sintering process resulted in the grain coarsening phenomenon of the Cr-31.2 mass% Ti alloys after 1250°C hot-press sintering at 50 MPa for 1h. In addition, the Cr-31.2 mass% Ti alloys were fabricated with the submicron-structured titanium (760 nm) and chromium (588 nm) powders showed more effective compaction than the micron-structured titanium (760 nm) and chromium (4.66 μm) powders did. The closed porosity decreases to 0.02% and the hardness values increase to 83.23 HRA. However, the agglomeration phenomenon of the Cr phase and brittleness of the TiCr2 Laves phases easily led to a slight decrease in TRS (400.54 MPa).
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 4; 1715-1723
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Parameter calibration for the discrete element simulation model of commercial organic fertilizer
Autorzy:
Xie, C.
Yang, J.
Wang, B.
Zhuo, P.
Li, C.
Wang, L.
Powiązania:
https://bibliotekanauki.pl/articles/2082983.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
commercial organic fertilizer
discrete element
repose angle
parameter calibration
parameters for the particle
model
Opis:
The parameters of a discrete element simulation model for commercial organic fertilizer particles were obtained both quickly and accurately, so that the uniformity and stability of the fertilizer discharged from the feeder may be studied using the discrete element simulation method. This study screened out the parameters which significantly influenced the repose angle of the commercial organic fertilizer using the Plackett-Burman test. Then, a model for the quadratic regression response surface of the repose angle vs the parameters was established through a Box-Behnken experiment with the measured repose angle of the fertilizer particles as the optimization index. The optimization results showed that the rolling friction coefficient and static friction coefficient between the fertilizer particles, as well as the optimal simulation parameter for the Johnson-Kendall-Roberts surface energy were 0.056, 0.355 and 0.011 J m-2, respectively. A discrete element simulation test was carried out with the optimal simulation parameters, and the repose angle error of the simulation test was found to be 0.40% relative to that of the physical test, which proved the accuracy and validity of the simulation parameters for the discrete element model of the organic fertilizer. The simulation results may provide the basic parameters for establishing a discrete element model of commercial organic fertilizer particles and investigating the performance of organic fertilizer feeders using the simulation method.
Źródło:
International Agrophysics; 2021, 35, 1; 107-117
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Remote pipeline pumping transportation of cemented tailings backfill slurry
Przetłaczanie na znaczne odległości zawiesiny zawierającej odpady poflotacyjne oraz cement rurociągami z wykorzystaniem pomp
Autorzy:
Xiao, S.
Liu, Z.
Jiang, Y.
Li, C.
Sun, C.
Su, L.
Powiązania:
https://bibliotekanauki.pl/articles/219530.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
opory przepływu
przetłaczanie
eksperyment z wykorzystaniem linii obiegowej rurociągu
właściwości reologiczne
CFD (Computational Fluid Dynamics)
strong resistance
pipe pumping
pumping looping pipe experiment
rheological characteristic
CFD
Opis:
For most precious metal mines, cemented tailings backfill slurry (CTBS) with different cement-sand ratio and solid concentration are transported into the gobs to keep the stability of the stope and mitigate environmental pollution by mine tailing. However, transporting several kinds of CTBS through the same pipeline will increase the risk of pipe plugging. Therefore, the joint impacts of cement-sand ratio and solid concentration on the rheological characteristics of CTBS need a more in-depth study. Based on the experiments of physical and mechanical parameters of fresh slurry, the loss of pumping pressure while transporting CTBS with different cement-sand ratio, flux and solid mass concentration were measured using pumping looping pipe experiments to investigate the joint impacts of cement-sand ratio and solid concentration on the rheological characteristics of CTBS. Meanwhile, the effect of different stopped pumping time on blockage accident was revealed and discussed by the restarting pumping experiments. Furthermore, Fluent software was applied to calculate the pressure loss and velocity distribution in the pipeline to further analysis experimental results. The overall trends of the simulation results were good agreement with the experiment results. Then, the numerical model of the pipeline in the Sanshandao gold mine was conducted to simulate the characteristics of CTBS pipeline transportation. The results show that the pumping pressure of the delivery pump can meet the transportation requirements when there is no blockage accident. This can provide a theoretical method for the parameters optimizing in the pipeline transportation system.
W większości kopalń metali szlachetnych zawiesina zawierająca odpady poflotacyjne wraz z cementem w różnych proporcjach cementu i piasku oraz o różnym stężeniu części stałych transportowana jest do wyrobisk i zrobów, gdzie wykorzystywana jest następnie do stabilizacji w rejonie przodka, ponadto w ten sposób ogranicza się zanieczyszczenie środowiska odpadami poflotacyjnymi. Jednakże przetłaczanie różnych rodzajów zawiesin w tym samym układzie rurociągu zwiększa ryzyko zaczopowania rur. Zbadanie wpływu proporcji cementu do piasku w zawiesinie oraz stężenia części stałych na charakterystykę reologiczną zawiesiny wydaje się kwestią kluczową. W oparciu o badania eksperymentalne fizycznych i mechanicznych parametrów świeżej zawiesiny, dokonano pomiarów spadku ciśnienia pompowania w trakcie przetłaczania zawiesin o zawartości cementu i pisaku w różnych proporcjach, dla różnych natężeń przepływu i stężeń części stałych w eksperymentach z wykorzystaniem linii obiegowej rurociągu. Celem eksperymentu było określenie łącznego wpływu proporcji cementu do piasku oraz stężenia części stałych na właściwości reologiczne zawiesiny. Ponadto, przeanalizowano w jaki sposób długość przerw w procesie przetłaczania wpływa na zwiększenie ryzyka zatkania rur i przeprowadzono eksperymenty polegające na wznowieniu pracy pomp. Analizę wyników eksperymentów uzupełniono poprzez zastosowanie oprogramowania Fluent do obliczenia spadku ciśnienia w rurociągu oraz rozkładu prędkości. Wykazano, że wyniki symulacji pozostawały w dużej zgodności z wynikami eksperymentów. W kolejnym kroku opracowano model numeryczny rurociągu eksploatowanego w kopalni złota Sanshandao dla potrzeb symulacji procesu przetłaczania zawiesiny. Uzyskane wyniki wskazują, że ciśnienie tłoczenia w pompie jest na wymaganym poziomie gdy nie występuje zablokowanie przepływu w rurze, i wykorzystane być mogą jako uzupełnienie teoretycznych metod optymalizacji parametrów układu transportowania i przetłaczania zawiesiny.
Źródło:
Archives of Mining Sciences; 2018, 63, 3; 647-663
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mineralogical and chemical characteristics of the lead-zinc tailing and contaminated soil from the mine tailing pond in Hunan Province (China)
Autorzy:
Li, C.
Zeng, L.
Fu, J.
Chen, J.
He, J.
He, Z.
Powiązania:
https://bibliotekanauki.pl/articles/110442.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
mineralogical characteristics
chemical fractionation
remediation
Opis:
The mineralogical and chemical characteristics of heavy metals in tailings and soils is an imperative for potential ecological risk assessment of metals to environment and heavy metals pollution prevention and control. The lead-zinc tailing and contaminated soil in and near the tailing pond were sampeled from a mine tailing pond in Hunan province (China), in which the chemical composition, phase composition and thermal behavior of tailing and soil were investigated. Furthermore, the petrography of lead-zinc tailing and chemical fractionations of Pb and Zn in the contaminated soil were studied in details. The mineral phases of lead-zinc tailing were galena, pyrite, chalcopyrite, sphalerite, quartz and fluorite, as distinguished by the reflected light microscopy and further proofed by the scanning electron microscope-energy dispersive spectrometer under the back scattered electron mode. Chemical fractionations were carried out by the European Community Bureau of Reference (BCR) sequential extraction procedure for Pb and Zn in the soil and the mild acido-soluble (F1), reducible (F2), oxidizable (F3), and residual (F4) fractions were 5.90, 75.24, 4.90 and 13.96% for Pb, and 47.74, 34.06, 9.59 and 8.61% for Zn, respectively. Subsequently, the individual contamination factor (ICF) of Pb and Zn were calculated as 6.16 and 10.61, respectively. The DTPA-available content of Pb and Zn in the contaminated soil were 39.9 and 170.7 mg·kg-1, respectively. The study provided a base for selecting remediation strategies in the studied area.
Źródło:
Physicochemical Problems of Mineral Processing; 2017, 53, 2; 1133-1147
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental study on triboelectrostatic beneficiation of wet fly ash using Microwave Heating
Autorzy:
Li, H.
Chen, Y.
Zhang, X.
Zhao, Y.
Tao, Y.
Li, C.
He, X.
Powiązania:
https://bibliotekanauki.pl/articles/110399.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
wet fly ash
triboelectrostatic beneficiation
microwave heating
efficiency
Opis:
Triboelectrostatic beneficiation, as a physical method, of fly ash cannot only meet the technical requirements of fly ash application but also recycle of an unburned carbon as a useful energy source. The aim of this study was to investigate the feasibility of improving efficiency of triboelectrostatic beneficiation of wet fly ash using microwave heating. The wet fly ash with different moisture contents had an average loss-on-ignition of 12.56%. The fly ash samples were heated in a microwave oven before the experiments. The experimental conditions were electric field voltage of 40 kV and air flux ranging from 12 to 30 m3/h. The influence of the microwave heating on the wet fly ash triboelectrostatic beneficiation was discussed under the conditions of different microwave intensity and irradiation time. The results indicated that the removal rate and recycle rate of the unburned carbon showed a significant increase performance as the wet fly ash was processed by the microwave heating which was attributed to changes of moisture contents and dielectric constants caused by the microwave heating. The feasibility had been verified according to the experimental study on fly ash with different moisture contents. It can be concluded that the microwave heating process was efficiently applied for the wet fly ash triboelectrostatic beneficiation.
Źródło:
Physicochemical Problems of Mineral Processing; 2016, 52, 1; 328-341
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Polarization-independent metal-dielectric grating with improved bandwidth
Autorzy:
Wang, B
Li, H
Shu, W
Li, W
Li, C
Lei, L
Zhou, J
Powiązania:
https://bibliotekanauki.pl/articles/174684.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
rigorous coupled-wave analysis
reflective efficiency
improved bandwidth
Opis:
A polarization-independent reflective grating with improved bandwidth is presented based on the mixed metal-dielectric grating. The novel grating is composed of the substrate, the metal slab, two dielectric layers, and the covering layer. The grating parameters are optimized for the special duty cycle of 0.6 at an incident wavelength of 1550 nm used in dense wavelength division multiplexing (DWDM). With the designed grating, high efficiency can be diffracted into the reflective –1st order for both TE and TM polarizations, where the polarization-independence is exhibited. Most importantly, the efficiency of more than 90% can be achieved within the incident wavelength bandwidth of 1262–1686 nm, where the bandwidth is improved greatly compared with the reported surface-relief single-layer grating. The reflective grating can have advantages of high efficiency, polarization-independence, and wide bandwidth, which should be useful for DWDM applications.
Źródło:
Optica Applicata; 2015, 45, 1; 71-77
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
National Income, Strategic Discontinuity, and Converging Trajectories of Macroeconomic Policy Initiatives: An Empirical Study of China
Autorzy:
Lux Tonn, Victor
Wendian, Chen
Li, Hsi C.
Powiązania:
https://bibliotekanauki.pl/articles/615888.pdf
Data publikacji:
2018
Wydawca:
Uniwersytet im. Adama Mickiewicza w Poznaniu
Tematy:
strategic discontinuity
systemic changes
econometric testing
advancing economy
China
Opis:
The framework of converging trajectories of macroeconomic policy initiatives is employed in the context of strategic discontinuity to study the national income of an advancing economy. A model of systemic changes based upon an equation of production and consumption is presented. In this study of the Chinese economy of 1980-2014, over time, the dynamics of policy imbalance is found to decrease considerably, which is consistent with the decreasing trend of shrinking the differences among the impact coefficients of government consumption, private investment, and private consumption.
Źródło:
Przegląd Politologiczny; 2018, 4; 131-152
1426-8876
Pojawia się w:
Przegląd Politologiczny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A strain of pathogenic Bacillus subtilis results in brain damage in ducklings when co-infected with Riemerella anatipestifer
Autorzy:
Zhu, T.S.
Chen, F.F.
Li, J.C.
Powiązania:
https://bibliotekanauki.pl/articles/2087854.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Bacillus subtilis
co-infection
Riemerella anatipestifer
duckling
opportunistic pathogen
Nauki Biologiczne i Rolnicze
Źródło:
Polish Journal of Veterinary Sciences; 2017, 4; 803-809
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Processing Techniques on Mechanical Properties and Impact Initiation of an Al-PTFE Reactive Material
Autorzy:
Feng, B.
Fang, X.
Li, Y.-C.
Wu, S.-Z.
Mao, Y.-M.
Wang, H.-X.
Powiązania:
https://bibliotekanauki.pl/articles/358654.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
Al-PTFE
reactive materials
quasi-static compression
impact initiation
Opis:
Reactive materials (RMs) or impact-initiated materials have received much attention as a class of energetic materials in recent years. To assess the influence of processing techniques on mechanical properties and impact initiation behaviors of an Al-PTFE reactive material, quasi -static compression tests and drop-weight tests were performed. Scanning electron microscopy (SEM) was used to identify the characteristics of the interior microstructures of the Al-PTFE samples. A sintering process was found to transform Al-PTFE from a brittle to a ductile material with an increased elasticity modulus (from 108-160 MPa to 256-336 MPa) and yield stress (from 12-16 MPa to 19-20 MPa). Increasing the molding pressure from 36 MPa to 182 MPa increased the elastic modulus of all Al-PTFE samples and also the yield stress of unsintered ones. Unsintered samples in general required less energy to initiate than sintered ones. As the molding pressure increased, the impact initiation energy for sintered Al-PTFE fell from 96 J to 68 J, whereas the initiation energy for unsintered Al-PTFE rose from 68 J to 85 J. PTFE nanofiber networks observed in sintered samples formed under the higher molding pressures could contribute to the opposite trends observed in the impact initiation energy of unsintered and sintered Al-PTFE samples.
Źródło:
Central European Journal of Energetic Materials; 2016, 13, 4; 989-1004
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hydrogen sulfide modulates gastric acid secretion in rats via involvement of substance P and nuclear factor-kappaB signaling
Autorzy:
Sun, H.-Z.
Gong, X.-Y.
Wu, L.
Wang, X.-X.
Nie, Y.-N.
Shang, R.
Wang, H.
Li, Y.-C.
Sun, Q.-F.
Gao, P.-F.
Bi, J.-X.
Powiązania:
https://bibliotekanauki.pl/articles/69523.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Fizjologiczne
Tematy:
hydrogen sulphide
gastric acid secretion
rat
nuclear factor-kappaB
substance P
transient receptor potential vanilloid type 1
neurokinin-1
Źródło:
Journal of Physiology and Pharmacology; 2018, 69, 3
0867-5910
Pojawia się w:
Journal of Physiology and Pharmacology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of inner and outer scale on beam spreading for a Gaussian wave propagating through anisotropic non-Kolmogorov turbulence
Autorzy:
Gao, C.
Li, X.
Powiązania:
https://bibliotekanauki.pl/articles/174609.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
anisotropy
Gaussian wave
long-term spreading radius
non-Kolmogorov turbulence
inner scales of turbulence
outer scales of turbulence
Opis:
Experimental results and empirical research have shown that atmospheric turbulence can present the anisotropic property not only at a few meters above the ground but also at high altitudes of up to several kilometers. This paper investigates beam spreading for a Gaussian wave propagating along a horizontal path in weak anisotropic non-Kolmogorov turbulence. Mathematical expressions for the long-term beam spreading radius were obtained based on the generalized von Kármán spectrum for anisotropic turbulence. The final model includes an anisotropic factor, which parameterizes the asymmetry of a turbulence cell, the spectral power law for non-Kolmogorov turbulence, the inner and outer scale of turbulence, and other essential optical parameters of a Gaussian wave. Numerical simulations indicate that the long-term beam spreading radius decreases with an increase in the anisotropic factor. We also analyze how the geometrical optics approximation may cause large errors for a small spectral power law value.
Źródło:
Optica Applicata; 2017, 47, 1; 63-74
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of the Structure and Properties of Wool and Cashmere Fibrrs under Potassium Permanganate Treatment
Porównanie struktury i właściwości włókien wełnianych i kaszmirowych po obróbce nadmanganianem potasu
Autorzy:
Li, L.
Qin, C.
Liu, C.
Powiązania:
https://bibliotekanauki.pl/articles/233343.pdf
Data publikacji:
2018
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
wool fibres
cashmere fibres
potassium permanganate
scale
force loss
włókna wełniane
włókno kaszmirowe
nadmanganian potasu
skala
utrata siły
Opis:
In this study, the weight loss and tensile property of wool fibers and cashmere fibers before and after various potassium permanganate solution treatment were investigated. The scale morphology andcrystallization index of the original and treated fibers were analysed with scanning electron microscopy and X-ray diffraction analysis. The experimental results showed that the weight loss of wool fibers is more than that of cashmere fibers under low potassium permanganate content treatment, but is less than that of cashmere fibers under high potassium permanganate content treatment. The force loss of cashmere fibers increased linearly with an increase in potassium permanganate content. The scales of cashmere fiber were damaged at a potassium permanganate content of 9%, but the scales of wool fiber were clear. The relative crystallisation index of treated wool is twice as that of treated cashmere at a potassium permanganate content of 9%.
W pracy zbadano utratę masy i wytrzymałość na rozciąganie włókien wełnianych i kaszmirowych przed i po zastosowaniu różnych roztworów nadmanganianu potasu. Morfologię i wskaźnik krystalizacji pierwotnych i poddanych obróbce włókien analizowano za pomocą skaningowej mikroskopii elektronowej i dyfrakcji rentgenowskiej. Wyniki eksperymentalne wykazały, że ubytek masy włókien wełnianych jest większy, niż w przypadku włókien kaszmirowych po zastosowaniu obróbki nadmanganianem potasu. Utrata wytrzymałości włókien kaszmirowych wzrastała liniowo wraz ze wzrostem zawartości nadmanganianu potasu. Stwierdzono, że względny wskaźnik krystalizacji wełny poddanej obróbce jest dwukrotnie większy, niż w przypadku kaszmiru poddanego obróbce przy zawartości nadmanganianu potasu wynoszącej 9%.
Źródło:
Fibres & Textiles in Eastern Europe; 2018, 4 (130); 29-33
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Delay-dependent dissipative control for stochastic singular systems with state delay
Autorzy:
Ding, C.
Li, Q.
Powiązania:
https://bibliotekanauki.pl/articles/229379.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
stochastic singular system
dissipative control
delay-dependent
state delay
linear matrix inequalities (LMIs)
Opis:
The problem of delay-dependent dissipative analysis and control for stochastic singular systems with state delay is investigated in this paper. Delay-dependent dissipative condition for the stochastic singular systems with state delay is obtained by employing singular stochastic Lyapunov and LMI-based methods. Based on this condition, a delay-dependent dissipative controller is presented. A numerical example is provided to demonstrate the effectiveness of the proposed approach.
Źródło:
Archives of Control Sciences; 2013, 23, 3; 281-293
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The interval Shapley value of an M/M/1 service system
Autorzy:
E, C. G.
Li, Q. L.
Li, S.
Powiązania:
https://bibliotekanauki.pl/articles/330815.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
M/M/1 service system
cooperative interval game
cost allocation
Shapley value
gra przedziałowa kooperatywna
alokacja kosztów
wartość Shapley'a
Opis:
Service systems and their cooperation are one of the most important and hot topics in management and information sciences. To design a reasonable allocation mechanism of service systems is the key issue in the cooperation of service systems. In this paper, we systematically introduce the interval Shapley value as cost allocation of cooperative interval games ,[...] arising from cooperation in a multi-server service system, and provide an explicit expression for the interval Shapley value of cooperative interval games [...]. We construct an interval game [...] of a service system which shares the same value for the grand coalition with the original interval game, by using the characteristic function which is dominated by the function of the original interval game. Finally, we prove that the interval game [...] is concave, which means that the interval Shapley value of the interval game [...] is in the interval core of this interval game, and illustrate this conclusion by using numerical examples.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2017, 27, 3; 549-562
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Quadratic performance analysis of switched affine time-varying systems
Autorzy:
Li, W.
Huang, C.
Zhai, G.
Powiązania:
https://bibliotekanauki.pl/articles/330032.pdf
Data publikacji:
2018
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
switched affine system
time varying system
quadratic stabilization
tracking
L2 gain
switching law
differential LMIs
observer
system zmienny w czasie
stabilizacja kwadratowa
śledzenie
obserwator
Opis:
We analyze quadratic performance for switched systems which are composed of a finite set of affine time-varying subsystems, where both subsystem matrices and affine vectors are switched, and no single subsystem has desired quadratic performance. The quadratic performance indexes we deal with include stability, tracking and L2 gain. We show that if a linear convex combination of subsystem matrices is uniformly Hurwitz and another convex combination of affine vectors is zero, then we can design a state-dependent switching law (state feedback) and an output-dependent switching law (output feedback) such that the entire switched affine system is quadratically stable at the origin. In the case where the convex combination of affine vectors is nonzero, we show that the tracking control problem can be posed and solved using a similar switching strategy. Finally, we consider the L2 gain analysis problem for the switched affine time-varying systems under state feedback.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2018, 28, 3; 429-440
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Model tests for shallow-water ship maneuverability in Three Gorges Reservoir
Autorzy:
Cai, C.
Cai, X.
Li, Y.
Powiązania:
https://bibliotekanauki.pl/articles/259922.pdf
Data publikacji:
2015
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
shallow-water test of ship model
simulated computation
maneuverability calibration
scale effect
Z shape test
K and T indexes
navigation safety
Opis:
This paper conducts calibration tests on the shallow-water maneuverability of 1:100 ship models for the typical navigation fleets in Three Gorges Reservoir. Major influential factors for the maneuverability similitude between models and prototypes and for scale effect were identified. A correction method for model scale was also established through model tests. Test results indicate that, by correcting the model scales of various fleets based on scale effect, the maneuverability indexes K’ (dimensionless of K) and T’ (dimensionless of T) of ship models are suitable for shallowwater tests, and properly reflect the maneuvering characteristics of prototypes. The findings provide an experimental basis for the navigation safety in Three Gorges Reservoir.
Źródło:
Polish Maritime Research; 2015, S 1; 136-140
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Robust adaptive fuzzy filters output feedback control of strict-feedback nonlinear systems
Autorzy:
Tong, S.
Liu, C.
Li, Y.
Powiązania:
https://bibliotekanauki.pl/articles/908148.pdf
Data publikacji:
2010
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
system nieliniowy
sterowanie rozmyte
sprzężenie zwrotne
nonlinear system
adaptive fuzzy control
backstepping
small-gain approach
K-filters
Opis:
In this paper, an adaptive fuzzy robust output feedback control approach is proposed for a class of single input single output (SISO) strict-feedback nonlinear systems without measurements of states. The nonlinear systems addressed in this paper are assumed to possess unstructured uncertainties, unmodeled dynamics and dynamic disturbances, where the unstructured uncertainties are not linearly parameterized, and no prior knowledge of their bounds is available. In recursive design, fuzzy logic systems are used to approximate unstructured uncertainties, and K-filters are designed to estimate unmeasured states. By combining backstepping design and a small-gain theorem, a stable adaptive fuzzy output feedback control scheme is developed. It is proven that the proposed adaptive fuzzy control approach can guarantee the all the signals in the closed-loop system are uniformly ultimately bounded, and the output of the controlled system converges to a small neighborhood of the origin. The effectiveness of the proposed approach is illustrated by a simulation example and some comparisons.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2010, 20, 4; 637-653
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Buckling analysis of airframe jointed panel under combined loading
Autorzy:
Li, X.
Jia, D.
Meng, C.
Powiązania:
https://bibliotekanauki.pl/articles/264575.pdf
Data publikacji:
2018
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
wytrzymałość
wyboczenie
obciążenie
strength
buckling analysis
jointed panel
combined loading
Opis:
The complicated relationship of the high order static indeterminate structure will lead to a lot of calculation work. The strength analysis of the structure is very difficult. In aircraft design phase, a structural simplified method should be used to model the load characteristics of the structure. In the paper, the buckling analysis of airframe jointed panel is investigated under combined loading and the effect of jointed position to buckling load is also presented. For the buckling analysis of special joined structure, one new method which is better than traditional methods is described.
Źródło:
International Journal of Applied Mechanics and Engineering; 2018, 23, 4; 1035-1042
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Compressive optical image encryption using phase-shifting interferometry on a joint transform correlator
Autorzy:
Li, J.
Jia, B.
Dai, X.
Lei, M.
Yang, C.
Li, H.
Li, R.
Powiązania:
https://bibliotekanauki.pl/articles/174905.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
fully optical system
holographic interferometry
joint transform correlator (JTC)
binary scrambling method
inverse problems
Opis:
A compressive optical image encryption method, which combines compressive sensing with phase-shifting interferometry on a joint transform correlator, is proposed in the fully optical domain. The object image is first permutated using a binary scrambling method. Next, the permutated object field is encrypted and registered as the holograms by phase-shifting interferometry on the joint transform correlator setup. Then, the encrypted images and the key are compressed to the compressed data using single-pixel compressive imaging. The original image can be reconstructed and decrypted using the specified algorithm. The simulations demonstrate that the method is effective and suitable for image security transmission.
Źródło:
Optica Applicata; 2017, 47, 2; 245-256
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A generalized varying-domain optimization method for fuzzy goal programming with priorities based on a genetic algorithm
Autorzy:
Li, S. Y.
Hu, C. F.
Teng, C. J.
Powiązania:
https://bibliotekanauki.pl/articles/970454.pdf
Data publikacji:
2004
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
rozmyte programowanie celowe
priorytet
algorytm genetyczny
fuzzy goal programming
priorities
SQP
genetic algorithm
GENOCOP III
Opis:
This paper proposes a generalized domain optimization method for fuzzy goal programming with different priorities. According to the three possible styles of the objective function, the domain optimization method and its generalization are correspondingly proposed. This method can generate the results consistent with the decision-maker's priority expectations, according to which the goal with higher priority may have higher level of satisfaction. However, the reformulated optimization problem may be nonconvex for the reason of the nature of the original problem and the introduction of the varying-domain optimization method. It is possible to obtain a local optimal solution for nonconvex programming by the SQP algorithm. In order to get the global solution of the new programming problem, the co-evolutionary genetic algorithm, called GENOCOP III, is used instead of the SQP method. In this way the decision-maker can get. the optimum of the optimization problem. We demonstrate the power of this proposed method based on genetic algorithm by illustrative examples.
Źródło:
Control and Cybernetics; 2004, 33, 4; 633-652
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Potato waste treatment by microbial fuel cell. Evaluation based on electricity generation, organic matter removal and microbial structure
Autorzy:
Du, H.
Li, F.
Huang, K.
Li, W.
Feng, C.
Powiązania:
https://bibliotekanauki.pl/articles/206898.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
water treatment
performance
technology
bacterial
recovery
sludge
carbon
microbial fuel cell
COD
potato waste
uzdatnianie wody
ChZT
węgiel
odpady ziemniaczane
Opis:
The performance of microbial fuel cell (MFC) in treating potato waste was evaluated using a two-chamber MFC supplied with potato liquid after mastication of market available fresh potato. Evaluation was conducted based on electricity generation, organic matter removal (CODCr, DOC and volatile fatty acids (VFAs)), and microbial structure on the anode and in the anodic solution of the reactor. Current density exhibited a trend that followed the concentration changes of organic matter in the solution, with its highest value being observed as 208 mA/m2. Effective removal of organic matter was also observed. By the end of the experiment, the removal for total COD reached about 84%. Bacterial structure analysis based on PCR, DGGE and sequencing indicated that more species were developed in the anodic solution than on the anode, with Proteobacteria, Firmicutes and Bacteroides being dominant. Geobacter, a well reported exoelectrogenic species, was found more predominant on the anode than in the anodic solution. The results thus indicated that simultaneous stabilization and electricity generation could be achieved when potato waste is treated in MFC.
Źródło:
Environment Protection Engineering; 2017, 43, 1; 5-18
0324-8828
Pojawia się w:
Environment Protection Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The synergistic effect of boric acid and ammonium polyphosphate on the thermal degradation and flammability of pine-needles
Autorzy:
Li, L.
Hu, H.
Guo, C.
Powiązania:
https://bibliotekanauki.pl/articles/52633.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technologii Drewna
Tematy:
synergistic effect
boric acid
ammonium polyphosphate
thermal degradation
flammability
pine needle
needle
pyrolysis
temperature
flame retardant
Opis:
The synergistic effect of ammonium polyphosphate (APP) and boric acid (BA) on the flame retardancy and thermal degradation of pine needles was investigated. Thermogravimetric analysis (TGA) showed that the presence of an ammoniumpolyphosphate and boric acid system increased the char residue and decreased the pyrolysis temperature of the pine needles. The derivative thermogravimetric analysis (DTG) showed that the ammonium polyphosphate and boric acid had shifted the degradation peaks of the pine needles to lower temperatures. The cone calorimetry test results showed that the values of HRR, THR, SPR, TSP and the mass loss (%) of the pine needles treated with ammonium polyphosphate and boric acid (APP/BA = 3/2)were significantly lower than the other samples. Therefore, the APP and BA system had a better effect on the pine needles overall than the APP alone.
Źródło:
Drewno. Prace Naukowe. Doniesienia. Komunikaty; 2014, 57, 193
1644-3985
Pojawia się w:
Drewno. Prace Naukowe. Doniesienia. Komunikaty
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation on a quasi-zero-stiffness vibration isolator under random excitation
Autorzy:
Wang, Y.
Li, S.
Cheng, C.
Powiązania:
https://bibliotekanauki.pl/articles/281608.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
vibration isolator
quasi-zero-stiffness
random excitation
dynamic analysis
performance analysis
Opis:
The dynamic response and isolation performance of a Quasi-Zero-Stiffness (QZS) vibration isolator using inclined springs as negative stiffness correctors under random excitation are presented in this paper. The probabilistic linearization method is employed to determine the dynamic response of the QZS vibration isolator and compared with the exact solution based on the Fokker-Planck-Kolmogorov (FPK) equation and the equivalent linearization method. Two performance indexes (Mean Square Relative Displacement (MSRD) and Mean Square Acceleration (MSA)) are considered to evaluate the isolation performance of the QZS vibration isolator under random excitation and compared with the equivalent linear vibration isolator. The results show that the MSRD of the QZS vibration isolator is always lower than the equivalent linear vibration isolator, while the MSA of the QZS vibration isolator can be larger or lower than the equivalent linear vibration isolator based on the values of damping ratio and spectral density of the random excitation
Źródło:
Journal of Theoretical and Applied Mechanics; 2016, 54, 2; 621-632
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study on the Rotor Spinning Technology of Cotton Stalk Bark Fibers/Cotton Fibers
Badania nad technologią przędzenia włókien z kory szypułkowej bawełny w mieszankach z włóknami bawełnianymi
Autorzy:
Li, L.
Liu, L.
Qin, C.
Powiązania:
https://bibliotekanauki.pl/articles/231835.pdf
Data publikacji:
2018
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
cotton stalk bark fiber
cotton
blending
rotor spinning
włókno z kory szypułkowej
bawełna
mieszanie
wirowanie wirnika
Opis:
The length difference and low flexibility of cotton stalk bark fibers make fiber spinning difficult. In this work, cotton stalk bark fibers that were directly from degummed cotton stalk bark were wetted, carded and softened before sliver-marking, and then they were blended with cotton fibers for carding and spinning in various blending ratios. The results showed that a reasonable open roller speed was 6000 rpm for blending ratio 50/50, 7000 rpm for blending ratio 35/65, and 8000 rpm for blending ratio 20/80. The minimum yarn linear density was 60 tex for blending ratio 50/50, 50 tex for blending ratio 35/65, and 40 tex for blending ratio 20/80.
Różnica długości i niska elastyczność włókien z kory szypułkowej bawełny utrudniają przędzenie włókien. W pracy, włókna z kory szypułkowej bawełny, które były bezpośrednio odśluzowane z bawełnianej szypułki, zwilżono i zmiękczono, a póżniej zmieszano z włóknami bawełnianymi następnie zgrzeblono i przędzono w różnych stosunkach mieszania. Wyniki wykazały, że optymalna prędkość wynosiła 6.000 obrotów/minutę dla stosunku mieszania 50/50, 7.000 obrotów/minutę dla stosunku mieszania 35/65 i 8.000 obrotów na minutę dla stosunku mieszania 20/80. Minimalna gęstość liniowa przędzy wynosił i czystej bawełnya 60 tex dla stosunku mieszania 50/50, 50 tex dla stosunku mieszania 35/65 i 40 tex dla stosunku mieszania 20/80.
Źródło:
Fibres & Textiles in Eastern Europe; 2018, 6 (132); 68-70
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling of acoustic field for a parametric focusing source using the spheroidal beam equation
Autorzy:
Yu, L.
Li, J.
Shi, C.
Powiązania:
https://bibliotekanauki.pl/articles/258564.pdf
Data publikacji:
2015
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
parametric focusing source
difference frequency wave
SBE
acoustic field
Opis:
A theoretical model of acoustic field for a parametric focusing source on concave spherical surface is proposed. In this model, the source boundary conditions of the Spheroidal Beam Equation (SBE) for difference frequency wave excitation were studied. Propagation curves and beam patterns for difference frequency component of the acoustic field are compared with those obtained for Khokhlov-Zabolotskaya-Kuznetsov (KZK) model. The results demonstrate that the focused parametric model of SBE is good valid for a large aperture angle in the strongly focused acoustic field. It is also investigated that high directivity and good focal ability with the decreasing of downshift ratio and the increasing of half-aperture angle for the focused parametric model of SBE.
Źródło:
Polish Maritime Research; 2015, S 1; 43-47
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of selenium on the growth and photosynthetic characteristics of flue-cured tobacco (Nicotiana tabacum L.)
Autorzy:
Jiang, C.
Zu, C.
Shen, J.
Shao, F.
Li, T.
Powiązania:
https://bibliotekanauki.pl/articles/57536.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Botaniczne
Tematy:
selenium
growth
photosynthesis
tobacco plant
Nicotiana tabacum
carboxylation efficiency
Opis:
The objective of this study was to investigate the effect of Selenium (Se) supply (0, 3, 6, 12, 24 mg kg−1) on the growth, photosynthetic characteristics, Se accumulation and distribution of flue-cured tobacco (Nicotiana tabacum L.). Results showed that low-dose Se treatments (≤6 mg kg−1) stimulated plant growth but high-dose Se treatments (≥12 mg kg−1) hindered plant growth. Optimal Se dose (6 mg kg−1) stimulated plant growth by reducing MDA content and improving photosynthetic capability. However, excess Se (24 mg kg−1) increased MDA content by 28%, decreased net photosynthetic rate and carboxylation efficiency by 34% and 39%, respectively. The Se concentration in the roots, stems, and leaves of the tobacco plants significantly increased with increasing Se application. A linear correlation (R = 0.95, P < 0.01) was observed between Se level and tobacco plant tissue Se concentration. This correlation indicated that the tobacco plant tissues were not saturated within the concentration range tested. The pattern of total Se concentration in the tobacco plant tissues followed the order root > leaf > stem. The Se concentration in the roots was 3.17 and 7.57 times higher than that in the leaves and stems, respectively, after treatment with 24 mg kg−1 Se. In conclusion, the present study suggested that optimal Se dose (6 mg kg−1) improved the plant growth mainly by enhancing photosynthesis, stomatal conductance, carboxylation efficiency and Rubisco content in the flue-cured tobacco leaves. However, the inhibition of excess Se on tobacco growth might be due to high accumulation of Se in roots and the damage of photosynthesis in leaves.
Źródło:
Acta Societatis Botanicorum Poloniae; 2015, 84, 1
0001-6977
2083-9480
Pojawia się w:
Acta Societatis Botanicorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A velocity measurement method based on scaling parameter estimation of chaotic system
Autorzy:
Liu, L.
Hu, J.
He, Z.
Han, C.
Li, H.
Li, J.
Powiązania:
https://bibliotekanauki.pl/articles/220466.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
signal processing
parameter estimation
chaos
synchronization
Opis:
In this paper, we propose a new method of measuring the target velocity by estimating the scaling parameter of a chaos-generating system. First, we derive the relation between the target velocity and the scaling parameter of the chaos-generating system. Then a new method for scaling parameter estimation of the chaotic system is proposed by exploiting the chaotic synchronization property. Finally, numerical simulations show the effectiveness of the proposed method in target velocity measurement.
Źródło:
Metrology and Measurement Systems; 2011, 18, 2; 275-281
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental Investigation Of Segregation Of Carbon Atoms Due To Sub-Zero Cryogenic Treatment In Cold Work Tool Steel By Mechanical Spectroscopy And Atom Probe Tomography
Doświadczalne badania segregacji atomów węgla w stali narzędziowej do pracy na zimno po obróbce kriogenicznej metodą spektroskopii mechanicznej i tomografii atomowej
Autorzy:
Min, N.
Li, H. M.
Xie, C.
Wu, X. C.
Powiązania:
https://bibliotekanauki.pl/articles/351716.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
cryogenic treatment
isothermal martensite
atom probe tomography
mechanical spectroscopy
Cottrell atmosphere
obróbka kriogeniczna
izotermiczny martenzyt
tomografia atomowa
spektroskopia mechaniczna
atmosfera Cottrella
Opis:
In this work, we present mechanical spectroscopy of cold work tool steel subjected to sub-zero cryogenic soaking treatment to reveal the carbon segregation and the subsequent carbides refinement. The maximum of Snoek-Köster (SK) peak height was obtained in the sample subjected to soaking 1h at −130°C cryogenic treatment. The SK peak height is reduced with prolonging the soaking time. The results indicate that an increase in the height of SK peak is connected with an increase in dislocation density and the number of segregated carbon atoms in the vicinity of dislocations or twin planes after martensite transformation at −130°C which is confirmed by corresponding TEM and atom probe tomography measurement. Hence, it is suggested that the isothermal martensite, formed during the cryogenic soaking treatment decreases (APT) the height of SK peak.
W pracy przedstawiono wyniki spektroskopii mechanicznej stali narzędziowej do pracy na zimno poddanej obróbce kriogenicznej w celu odsłonięcia segregacji węgla i późniejszego tworzenia węglików. Dzięki połączeniu transmisyjnej mikroskopii elektronowej (TEM) i tomografii atomowej (APT) uzyskano maksymalny pik Snoek-Köstera (SK) w próbce poddanej obróbce kriogenicznej przez 1 godzinę w −130°C. Wysokość piku SK obniża się wraz z wydłużeniem czasu obróbki. Wyniki wskazują, że zwiększenie wysokości piku SK jest połączone ze wzrostem gęstości dyslokacji i liczby segregowanych atomów węgla w sąsiedztwie dyslokacji lub płaszczyzn bliźniaczych po przemianie martenzytycznej w -130°C, co potwierdzone jest odpowiednimi pomiarami TEM oraz APT. W związku z tym proponuje się, że izotermiczny martenzyt powstały podczas obróbki kriogenicznej zmniejsza wysokość piku SK.
Źródło:
Archives of Metallurgy and Materials; 2015, 60, 2A; 1109-1113
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Measurement of the Heat of Reaction of Polytetrafluoroethylene/Aluminum Composites Based on Laser Initiation
Autorzy:
Li, S.
Wu, Y.
Lin, Q.
Huang, C.
Yang, S.
Li, J.
Powiązania:
https://bibliotekanauki.pl/articles/358195.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
reactive materials
PTFE/Al composites
heat of reaction
laser initiation
Opis:
Polytetrafluoroethylene/aluminum (PTFE/Al) composites are reactive materials which can release energy due to exothermic chemical reactions initiated under shock loading conditions. In order to accurately measure the potential maximum heat of reaction of PTFE/Al composites in an inert atmosphere, we propose in this paper a heat of reaction measurement system based on laser initiation. Our results show that the measurement system successfully initiates the chemical reaction between PTFE and Al in an argon atmosphere. The comparison between theoretical calculations and experimental data demonstrates that our measurement method is highly accurate and exhibits excellent consistency. Thus, the heat of reaction measurement system based on laser initiation is applicable for measuring the heat of reaction of PTFE/Al composites and also other complicated reactive materials.
Źródło:
Central European Journal of Energetic Materials; 2017, 14, 3; 534-546
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nowa metoda analizy drzewa uszkodzeń: rozmyta analiza dynamicznego drzewa uszkodzeń
A new fault tree analysis method: fuzzy dynamic fault tree analysis
Autorzy:
Li, Y. F.
Huang, H. Z.
Liu, Y.
Xiao, N. C.
Li, H.
Powiązania:
https://bibliotekanauki.pl/articles/301632.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
analiza drzewa uszkodzeń
dynamiczne drzewo uszkodzeń
liczba rozmyta
rozmyty model Markowa
programowanie parametryczne
fault tree analysis (FTA)
dynamic fault tree
fuzzy number
fuzzy Markov model
parametric programming
Opis:
Fault tree analysis (FTA) is a widely used reliability assessment tool for large and complex engineering systems. The conventional fault tree analysis method, which contains AND, OR, and Voting gates, etc., can efficiently build an analytical model to represent combinations of component failures that cause the failure of a system. However, due to its limited modeling capability, we may confront difficulties when modeling dynamic systems which involve complicated dynamic characteristics such as sequence dependency and functional dependency. Markov-based dynamic fault tree analysis (DFTA) extends the static FTA by introducing additional gates to model such complicated interactions among events. In many circumstances, it is quite difficult to obtain an accurate system reliability estimate due to limited data. To overcome this issue, a fuzzy dynamic fault tree model is put forth to assess system reliability. To obtain the membership function of the fuzzy probability for the top event of the studied fault trees, the extension principle is employed to calculate the associated membership function via a pair of parametric programming problems. Finally, a case study is presented to demonstrate the application of the proposed approach for the hydraulic system of a CNC machining centre.
Analiza drzewa uszkodzeń (FTA) znajduje szerokie zastosowanie jako narzędzie oceny niezawodności dużych i złożonych systemów inżynierskich. Tradycyjna metoda analizy drzewa uszkodzeń z bramkami logicznymi typu AND, OR, k-z-n, itd. pozwala na sprawne konstruowanie modeli analitycznych reprezentujących kombinacje uszkodzeń elementarnych składowych systemu, które prowadzą do awarii systemu jako całości. Jednakże ograniczone możliwości modelowania jakie daje ta metoda mogą prowadzić do trudności przy modelowaniu systemów dynamicznych posiadających złożone charakterystyki dynamiczne, takie jak zależność sekwencyjna czy zależność funkcjonalna. Analiza dynamicznych drzew uszkodzeń (DFTA) oparta na metodzie Markowa stanowi rozszerzenie tradycyjnej FTA. Wprowadza ona dodatkowe bramki, pozwalając na modelowanie wspomnianych wyżej złożonych interakcji między zdarzeniami. W wielu okolicznościach, ograniczone dane nie pozwalają na otrzymanie dokładnej oceny niezawodności systemu. By rozwiązać ten problem, zaproponowano zastosowanie rozmytego modelu dynamicznego drzewa uszkodzeń do oceny niezawodności systemu. Aby otrzymać funkcję przynależności rozmytego prawdopodobieństwa wystąpienia zdarzenia szczytowego badanego drzewa uszkodzeń, obliczono, na podstawie pary problemów programowania parametrycznego, skojarzoną funkcję przynależności wykorzystując zasadę rozszerzenia. Na zakończenie przedstawiono studium przypadku, w którym proponowane podejście zastosowano do analizy systemu hydraulicznego centrum obróbkowego CNC.
Źródło:
Eksploatacja i Niezawodność; 2012, 14, 3; 208-214
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling of Microwave Cavities Based on SIBC-FDTD Method for EM Wave Focalization by TR Technique
Autorzy:
Li, Zhigang
Aimer, Younes
Bouazza, Tayeb H. C.
Powiązania:
https://bibliotekanauki.pl/articles/2142318.pdf
Data publikacji:
2022
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
curvilinear modeling
EM waves focalization
SIBCFDTD method
TR technique
Opis:
The time reversal (TR) techniques used in electromagnetics have been limited for a variety of reasons, including extensive computations, complex modeling and simulation, processes as well as, large-scale numerical analysis. In this paper, the SIBC-FDTD method is applied to address these issues and to efficiently model TR systems. An original curvilinear modeling method is also proposed for constructing various obstacles in a 2D microwave cavity and for processing the corners of the cavity. The EM waves’ spatio-temporal focalization has been realized, and results of the simulations further prove the accuracy and effectiveness of this modeling method. Furthermore, they demonstrate that the microwave cavity processes may significantly improve the focalization quality in terms of SSLL enhancement.
Źródło:
Journal of Telecommunications and Information Technology; 2022, 3; 59--66
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on the influence of driving harmonic on electromagnetic field and temperature field of permanent magnet synchronous motor
Autorzy:
Qiu, H.
Yu, W.
Li, Y.
Yang, C.
Powiązania:
https://bibliotekanauki.pl/articles/141535.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
air gap flux density
eddy current loss
harmonic
magnetic field decoupling
torque ripple
Opis:
At present, the drivers with different control methods are used in most of permanent magnet synchronous motors (PMSM). A current outputted by a driver contains a large number of harmonics that will cause the PMSM torque ripple, winding heating and rotor temperature rise too large and so on. In this paper, in order to determine the influence of the current harmonics on the motor performance, different harmonic currents were injected into the motor armature. Firstly, in order to study the influence of the current harmonic on the motor magnetic field, a novel decoupling method of the motor magnetic field was proposed. On this basis, the difference of harmonic content in an air gap magnetic field was studied, and the influence of a harmonic current on the air gap flux density was obtained. Secondly, by comparing the fluctuation of the motor torque in the fundamental and different harmonic currents, the influence of harmonic on a motor torque ripple was determined. Then, the influence of different current harmonics on the eddy current loss of the motor was compared and analyzed, and the influence of the drive harmonic on the eddy current loss was obtained. Finally, by using a finite element method (FEM), the motor temperature distribution with different harmonics was obtained.
Źródło:
Archives of Electrical Engineering; 2017, 66, 2; 295-312
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of struvite process for nutrient recovery from anaerobic digesters of livestock wastewater
Autorzy:
Zhang, T.
Fang, C.
Li, P.
Jiang, R.
Powiązania:
https://bibliotekanauki.pl/articles/207659.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
anaerobic digester
livestock wastewater
nutrient recovery
phosphate recovery
slow release fertilizers
struvite
beztlenowa komora fermentacyjna
ścieki hodowlane
odzyskiwanie składników odżywczych
nawozy o spowolnionym działaniu
nawozy wolnodziałające
odzysk fosforanów
struwit
Opis:
Process of struvite (Mg4NH4PO4·6H2O) precipitation is a promising method for phosphorus recycling. The use of cheap magnesium ore for precipitation struvite as phosphate recovery has been examined. The optimal conditions for precipitation are pH 9.0 and Mg2+: NH4 +: PO4 -3 molar ratio 1.1:30.7:1. Linear correlation of experimental data is in qualitative agreement with modelling calculation. Surface characterization analysis demonstrates that struvite is the dominant component of precipitate. Fertility value tests show that struvite precipitate could be available as slow-release fertilizer.
Źródło:
Environment Protection Engineering; 2014, 40, 3; 29-42
0324-8828
Pojawia się w:
Environment Protection Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Maintainability Allocation Method Based on Time Characteristics for Complex Equipment
Metoda alokacji obsługiwalności złożonych urządzeń oparta na charakterystykach czasowych
Autorzy:
Zhou, D.
Jia, X.
Lv, C.
Li, Y.
Powiązania:
https://bibliotekanauki.pl/articles/300709.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
maintainability
maintenance
allocation method
MTTR
obsługiwalność
eksploatacja
metoda alokacji
średni czas do naprawy MTTR
Opis:
Maintainability allocation is an important step in product quality design. Traditional allocation methods are limited such that the allocated mean time to repair for each unit design apartment cannot be totally controlled by the corresponding design apartment. This paper proposesa new time characteristics-based maintainability allocation method to solve the aforementioned problem. The relationship between design content and repair time is considered in this method, and repair time is divided into common and individual repair time. Common repair time, which isdetermined by the overall system design,is deducted from the total repair time. Individual repair time is allocated to the specific unit through proper traditional allocation method. A case study is performed,and results demonstrate that the new method is more suitable and effective than original methods in terms ofmaintainability allocation.
Alokacja obsługiwalności jest ważnym krokiem w projektowaniu jakości produktów. Tradycyjne metody alokacji są ograniczone w takim sensie, że alokowany średni czas do naprawy dla każdego działu projektowania jednostki produktu nie może być całkowicie kontrolowany przez odpowiedni dział projektowania. W niniejszej pracy zaproponowano rozwiązanie tego problemu wykorzystujące nową metodę alokacji obsługiwalności opartą na charakterystykach czasowych. W proponowanej metodzie bierze się pod uwagę związek między zawartością projektu a czasem naprawy, czas naprawy zaś dzieli się na wspólny i indywidualny. Wspólny czas naprawy, który zależy od ogólnej konstrukcji systemu, odejmuje się od całkowitego czasu naprawy. Indywidualny czas naprawy alokuje się do konkretnej jednostki za pomocą odpowiedniej tradycyjnej metody alokacji. W pracy przeprowadzono studium przypadku, którego wyniki pokazują, że nowa metoda jest bardziej odpowiednia i skuteczna jeśli chodzi o alokację obsługiwalności niż metodystosowane pierwotnie.
Źródło:
Eksploatacja i Niezawodność; 2013, 15, 4; 441-448
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation and characterization of high count yak wool yarns spun by complete compacting spinning and fabrics knitted from them
Przygotowanie i charakterystyka przędz o dużej masie liniowej z wełny jaków przędzionych systemem kompaktowym rotorowym oraz dzianiny wykonane z tych przędz
Autorzy:
Li, W.
Liu, X.
Liu, C.
Su, X.
Xie, C.
Wei, Q.
Powiązania:
https://bibliotekanauki.pl/articles/232629.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
yak wool
pure high count yarns
complete compacting spinning
CCS
yarn quality
knitted wearability
przędza z jaka
przędzenie kompaktowe
przędzenie obrączkowe
jakość przędzy
Opis:
The attentions of the textile industry has been attracted by yak wool due to its excellent properties, environmental friendly characteristics and inexpensive prices. However, the processing of yak wool is difficult due to the larger fiber dispersion and stiffness, especially spun pure and high count yak wool yarn. Therefore, in this paper, a kind of roller-type compact spinning - complete compacting spinning (CCS) was applied to spun pure high count yak wool yarns, in which a special hollow roller made of stainless steel with a strip groove structure on its surface was employed. Based on the mechanism of CCS, the processing parameters for two kinds of yak wool yarns - 20.83 tex and 16.67 tex were set. Then the qualities of the yarns prepared were tested and compared with yak wool yarns spun by common ring spinning. Finally corresponding knitted fabrics were further produced and tested for wearability.
Przemysł włókienniczy zainteresowany jest produkcją przędzy z jaków dzięki jej dobrej właściwości termicznej, przyjaznych ekologicznie warunkom hodowli i niskim cenom. Jednakże przetwarzanie wełny jaków jest trudne ze względu na duże rozrzuty właściwości tych włókien i ich sztywność co uwidacznia się szczególnie przy przędzeniu wełny jaków o dużych masach liniowych. Dla rozwiązania tego zagadnienia opracowano specjalny system przędzenia oparty na przędzeniu kompaktowym z zastosowaniem wydrążonego wałka ze stali kwasoodpornej ze szczeliną o odpowiedniej strukturze na jego powierzchni. Przedstawiono wytwarzanie przędz o masie liniowej ok. 20,8 tex i 16,7 tex. Właściwości wyprzędzionych przędź porównano z właściwościami przędz otrzymanych za pomocą konwencjonalnego przędzenia obrączkowego. Badania zakończono wyprodukowaniem i sprawdzeniem właściwości użytkowych różnych wyrobów dziewiarskich.
Źródło:
Fibres & Textiles in Eastern Europe; 2016, 1 (115); 30-35
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Process Optimization and Characterization of an HMX/Viton Nanocomposite
Autorzy:
Shi, X.
Wang, C.
Wang, J.
Li, X.
An, C.
Ji, W.
Powiązania:
https://bibliotekanauki.pl/articles/358667.pdf
Data publikacji:
2015
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
HMX
spray drying
processing parameters
optimization
impact sensitivity
nanoparticles
Opis:
HMX/Viton A nanocomposites were prepared by a spray drying process using different processing parameters, which included the dry gas inlet temperature, the air flow rate, and the solution feed flow rate. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to characterize the nanocomposites. The effects of the processing parameters on the morphology of the samples were investigated and are discussed. The thermal decomposition behaviour and impact sensitivity of the raw HMX and HMX/Viton A nanocomposites were also measured and compared. Optimal morphology and dispersion of the coated samples was achieved when the dry gas inlet temperature and the air and solution feed flow rates were 55 °C, 660 L/h and 1.5 mL/min, respectively. Under these optimal processing conditions, the nanocomposites were spherical in shape, ranged from 0.2-2 μm in size, and were composed of many tiny particles of 50-100 nm in size. The crystal phase of the nanocomposites was the same as that of raw HMX. Compared with those of raw HMX, the melting point and impact sensitivity of the nanocomposites were lower and the thermal decomposition rate was slightly higher.
Źródło:
Central European Journal of Energetic Materials; 2015, 12, 3; 487-495
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Acquisition of the Surface Morphology of Ruled Gratings with a Microscope Objective
Autorzy:
Li, Z.
Ma, L.
Liu, C.
Zhang, M.
Chen, X.
Cheng, C.
Powiązania:
https://bibliotekanauki.pl/articles/1189791.pdf
Data publikacji:
2015-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
42.30.Kq
42.87.-d
42.79.Dj
42.40.Kw
Opis:
In this paper, an optical microscope objective with large numerical number is inserted into a Mach-Zehnder interferometer, and this system is adopted to detect the surface morphologies of two ruled transmission gratings with area scale to a micrometer. The object waves transmitting from the gratings interfere with spherical reference wave, and the interferograms constructed are recorded by a high-resolution CCD. The surface maps of the gratings are retrieved from the interferograms, and the results are confirmed by the measurement with an atomic force microscope, with detection errors in nanometer scale. This work provides an optical non-destructive method for precise detection of small-area sophisticated object surfaces with an optical microscope objective.
Źródło:
Acta Physica Polonica A; 2015, 127, 6; 1630-1633
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improved method for phase wraps reduction in profilometry
Autorzy:
Du, G.
Wang, M.
Zhou, C.
Si, S.
Li, H.
Lei, Z.
Li, Y.
Powiązania:
https://bibliotekanauki.pl/articles/173793.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
phase unwrapping
zero-padding
Fourier transform
carrier-frequency
profilometry
Opis:
In order to completely eliminate, or greatly reduce the number of phase wraps in 2D wrapped phase map, Gdeisat and co-workers proposed an algorithm, which uses shifting the spectrum towards the origin. But the spectrum can be shifted only by an integer number, meaning that the phase wraps reduction is often not optimal. In addition, Gdeisat’s method will take much time to make the Fourier transform, inverse Fourier transform, select and shift the spectral components. In view of the above problems, we proposed an improved method for phase wraps elimination or reduction. First, the wrapped phase map is padded with zeros, the carrier frequency of the projected fringe is determined by high resolution, which can be used as the moving distance of the spectrum. And then realize frequency shift in spatial domain. So it not only can enable the spectrum to be shifted by a rational number when the carrier frequency is not an integer number, but also reduce the execution time. Finally, the experimental results demonstrated that the proposed method is feasible.
Źródło:
Optica Applicata; 2017, 47, 2; 295-306
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Identification of three species commonly known as“daqingye” by internal leaf anatomy and high-performance liquid chromatography analyses
Autorzy:
Zhang, Y.
Zhu, Y.
Chen, J.
Xia, C.
Deng, J.
Li, H.
Li, Y.
Li, J.
Liu, P.
Powiązania:
https://bibliotekanauki.pl/articles/59301.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Botaniczne
Opis:
The macroscopic and microscopic morphologies and indigo and indirubin concentration of the traditional Chinese medicine herbs Isatis indigotica Fort., Polygonum tinctorium Ait., and Baphicacanthus cusia (Nees) Bremek, all commonly known as “daqingye”, were determined and compared. The morphological analyses indicated that I. indigotica has leaves with winged petioles and no glandular hairs or crystals, P. tinctorium has leaves with membranous ocrea and clusters of calcium oxalate, and B. cusia has palisade cells in the mesophyll running over the main vein and single cells containing calcium carbonate crystals. Indigo and indirubin are chemical constituents that have been previously isolated from daqingye and were selected in this study as identification markers for high-performance liquid chromatography analysis due to their pharmacological activities. The chromatographic results showed that indigo and indirubin concentration varied significantly among the three species: high concentration of both indigo and indirubin were observed in I. indigotica, the highest concentration among the three daqingye plants was found in P. tinctorium but with low levels of indirubin, and the concentration of indigo and indirubin was quite low in B. cusia. In summary, three different species commonly known as daqingye were accurately distinguished by morphological observation, internal leaf anatomy analysis, and chromatographic analysis.
Źródło:
Acta Societatis Botanicorum Poloniae; 2018, 87, 1
0001-6977
2083-9480
Pojawia się w:
Acta Societatis Botanicorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Processing Technique and PerformanceEvaluation of High-Modulus Organic/Inorganic Puncture-Resisting Composites
Technika wytwarzania i ocena jakości wysoko modułowych organiczno-nieorganicznych kompozytów odpornych na przebicie
Autorzy:
Li, T T
Lou, C W
Lin, M C
Lin, J H
Powiązania:
https://bibliotekanauki.pl/articles/232410.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
composite
puncture resistance
thermal insulation
mechanical properties
recycle
kompozyty
odporność na przebicie
odporność termiczna
tkanina z włókien szklanych
włókna Kevlar
Opis:
The development of low-cost organic/inorganic puncture-resisting composites is suggested to improve their puncture resistance and thermal insulation properties. In this paper, recycled high modulus Kevlar fiber and glass fabric were used together with polyester/lowmelting polyester nonwovens. The result shows that the static puncture resistance improves proportionally with Kevlar fibers; but the dynamic puncture resistance remains the same at first and then rises up to 20 wt % for Kevlar fibers. The increasing low-melting polyester fibers on the surface result in an upward and then downward trend for both static and dynamic puncture resistances. The additional polyester/low-melting polyester nonwovens are beneficial for the improvement of puncture resistances. Moreover the thermal conductivity of all the composites is in range of 0.015-0.025 W/m·K. According to the results, Kevlar fibers are also shown to be advisable reinforcement to achieve better tensile and bursting strengths.
Badano możliwości zwiększenia odporności na przebicie oraz odporności termicznej tanich organiczno-nieorganicznych kompozytów. W badaniach stosowano wysoko modułowe włókna Kevlar z recyklingu oraz tkaninę z włókien szklanych łącznie z włókninami wykonanymi z niskotopliwego poliestru. Stwierdzono, że statyczna wytrzymałość na przebicie zwiększa się proporcjonalnie z ilością włókien Kevlar, ale dynamiczna wytrzymałość na przebicie pozostaje początkowo taka sama, a następnie wzrasta do zawartości włókien Kevlar 20%. Zastosowanie niskotopliwych włókien poliestrowych powoduje tendencje wzrastające, a następnie malejące dla wytrzymałości statycznej i dynamicznej. Stwierdzono, że dodatek włókien Kevlar jest korzystny dla wytwarzanych kompozytów.
Źródło:
Fibres & Textiles in Eastern Europe; 2014, 6 (108); 75-80
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation and Characterization of Ultrafine HMX/TATB Explosive Co-crystals
Autorzy:
An, C.
Li, H.
Zhang, Y.
Ye, B.
Xu, C.
Wang, J.
Powiązania:
https://bibliotekanauki.pl/articles/358105.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
HMX
TATB
ultrafine co-crystals
ball milling
mechanical sensitivity
Opis:
An explosive co-crystal of 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane (HMX) and 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) was prepared by the ball milling method. The raw materials and co-crystals were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC) and Raman spectroscopy. Impact and friction sensitivity of the co-crystals were tested and analyzed. The results showed that the HMX/TATB co-crystals are spherical in shape and 100-300 nm in size. The co-crystals are different from anintimate mixture of HMX/TATB and they exhibit a new co-crystal structure. HMX/TATB co-crystals are formed by N-O···H hydrogen bonding between −NO2 (HMX) and −NH2 (TATB). The drop height of ultrafine HMX/TATB explosive co-crystals is 12.7 cm higher than that of ultrafine HMX, whilst the explosion probability of friction is 20% lower than that of ultrafine HMX. Ultrafine HMX/TATB explosive co-crystals are difficult to initiate under impact and friction conditions.
Źródło:
Central European Journal of Energetic Materials; 2017, 14, 4; 876-887
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
One shot profilometry using iterative two-step temporal phase-unwrapping
Autorzy:
Du, G.
Wang, M.
Zhou, C.
Si, S.
Li, H.
Lei, Z.
Li, Y.
Powiązania:
https://bibliotekanauki.pl/articles/173912.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
phase unwrapping
composite fringe pattern
Fourier transform
two-step temporal phase-unwrapping
Opis:
This paper reviews two techniques that have been recently published for three-dimensional profilometry and proposes one shot profilometry using iterative two-step temporal phase-unwrapping by combining the composite fringe projection and the iterative two-step temporal phase unwrapping algorithm. In temporal phase unwrapping, many images with different frequency fringe pattern are needed to project, which would take much time. In order to solve this problem, Ochoa proposed a phase unwrapping algorithm based on phase partitions using a composite fringe. However, we found that the fringe order determined through the construction of phase partitions tended to be imprecise. Recently, we proposed an iterative two-step temporal phase unwrapping algorithm, which can achieve high sensitivity and high precision shape measurement. But it needs multiple frames of fringe images which would take much time. In order to take into account both the speed and accuracy of three-dimensional shape measurement, we get a new, and more accurate unwrapping method based on a composite fringe pattern by combining these two techniques. This method not only retains the speed advantage of Ochoa’s algorithm, but also greatly improves its measurement accuracy. Finally, the experimental evaluation is conducted to prove the validity of the proposed method.
Źródło:
Optica Applicata; 2017, 47, 1; 97-110
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study on the rheological properties of CL-20/HTPB casting explosives
Autorzy:
Li, H.-X..
Wang, J-Y.
An, C.-W.
Powiązania:
https://bibliotekanauki.pl/articles/358310.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
casting explosive
particle gradation
rheological properties
plasticizer
Opis:
The rheological properties of ε-2,4,6,8,10,12-hexanitro-2,4,6,8,10,12hexaazaisowurtzitane (CL-20)/hydroxy-terminated polybutadiene (HTPB) casting explosives with different formulations were tested and analyzed. The effects of both the weight percentage (wt.%) of CL-20 and its particle size, as well as the type and content of plasticizers, on the rheological properties of CL-20/HTPB casting explosives were investigated in detail. The results show that the viscosity and pseudoplasticity of CL-20/HTPB casting explosives increase with increasing wt.% of CL-20 and decreasing particle size. The gradation of CL-20 particle size also affects the rheological properties of the casting explosives. When the mixing ratio of 30 μm to 2 μm particles is 3:1, the viscosity reaches its lowest value and the non-Newtonian index reaches the maximum value of 0.5698. The viscosity, non-Newtonian index and impact sensitivity of the samples studied are clearly decreased by the addition of dioctyl adipate (DOA), dioctyl sebacate (DOS) or dibutyl phthalate (DBP). However, the three plasticizers do not appear to affect the thermal decomposition of CL-20/HTPB casting explosives. With respect to the rheological properties, mechanical properties and sensitivity, DOA is the optimum plasticizer to use in CL-20/HTPB casting explosives.
Źródło:
Central European Journal of Energetic Materials; 2014, 11, 2; 237-255
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A scheme of resource allocation and stability for peer-to-peer file-sharing networks
Autorzy:
Li, S.
Sun, W.
E, C. G.
Shi, L.
Powiązania:
https://bibliotekanauki.pl/articles/331243.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
peer-to-peer networks
fairness
pricing
stability
utility maximization
sieć peer-to-peer
wycena
maksymalizacja użyteczności
Opis:
Peer-to-peer (P2P) networks offer a cost-effective and easily deployable framework for sharing content. However, P2P file-sharing applications face a fundamental problem of unfairness. Pricing is regarded as an effective way to provide incentives to peers to cooperate. In this paper we propose a pricing scheme to achieve reasonable resource allocation in P2P file-sharing networks, and give an interpretation for the utility maximization problem and its sub-problems from an economic point of view. We also deduce the exact expression of optimal resource allocation for each peer, and confirm it with both simulation and optimization software. In order to realize the optimum in a decentralized architecture, we present a novel price-based algorithm and discuss its stability based on Lyapunov stability theory. Simulation results confirm that the proposed algorithm can attain an optimum within reasonable convergence times.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2016, 26, 3; 707-719
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study on detection of gross error in geodetic network adjustment
Autorzy:
Kim, J. H.
Kim, C. J.
Li, R. J.
Powiązania:
https://bibliotekanauki.pl/articles/145352.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
sieć geodezyjna
sieć triangulacyjna
geodezja satelitarna
geodetic network adjustment
gross error
robust estimation
equivalent weight
Opis:
Generally, gross errors exist in observations, and they affect the accuracy of results. We review methods to detect the gross errors by Robust estimation method based on L1-estimation theory and their validity in adjustment of geodetic networks with different condition. In order to detect the gross errors, we transform the weight of accidental model into equivalent one using not standardized residual but residual of observation, and apply this method to adjustment computation of triangulation network, traverse network, satellite geodetic network and so on. In triangulation network, we use a method of transforming into equivalent weight by residual and detect gross error in parameter adjustment without and with condition. The result from proposed method is compared with the one from using standardized residual as equivalent weight. In traverse network, we decide the weight by Helmert variance component estimation, and then detect gross errors and compare by the same way with triangulation network In satellite geodetic network in which observations are correlated, we detect gross errors transforming into equivalent correlation matrix by residual and variance inflation factor and the result is also compared with the result from using standardized residual. The results of detection are shown that it is more convenient and effective to detect gross errors by residual in geodetic network adjustment of various forms than detection by standardized residual.
Źródło:
Geodesy and Cartography; 2018, 67, 1; 57-69
2080-6736
2300-2581
Pojawia się w:
Geodesy and Cartography
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Abiotic mechanisms for biochar effects on soil N2O emission
Autorzy:
He, C.
Manevski, K.
Andersen, M.N.
Hu, C.
Dong, W.
Li, J.
Powiązania:
https://bibliotekanauki.pl/articles/2082642.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
gas diffusion
mitigation
nitrous oxide
water
filled pore space
Opis:
In this research, sterile soil columns with different contents of biochar made from apple-tree residues (0, 1 and 5% w/w) at three levels of water filled pore space (40, 60, and 80%) were set up in the laboratory to study nitrous oxide diffusion and binding processes. The results indicated that nitrous oxide emission can be effectively mitigated at 5% biochar regardless of soil water content. However, 1% biochar stimulated nitrous oxide diffusion compared to the other biochar treatments, which was opposite to expectations due to the stronger aeration than adsorption effect, while 0% had a suppression effect between 1 and 5%. Nitrous oxide emissions increased with increasing water filled pore space due to concomitantly decreasing biochar tortuousity at high water content. The increase of nitrogen from 1.11 to 1.50% on the biochar surface in the 5% treatment, and from 1.11 to 1.46% in the 100% biochar treatment, suggested that the main abiotic mechanisms for mitigation of nitrous oxide emission is adsorption and subsequent reactions with C = C bonds on appletree biochar surfaces since C = O and C-O bonds both increased and C=C/C-C/C-H declined.
Źródło:
International Agrophysics; 2019, 33, 4; 537-546
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of the Correlation between the Structure and Quality of Compact Blend Yarns
Ocena korelacji pomiędzy strukturą i jakością mieszankowych przędz kompaktowych przędzionych dwoma różnymi przędzarkami obrączkowymi
Autorzy:
Li, W.
Su, X.
Zhang, Y.
Xie, C.
Wei, Q.
Powiązania:
https://bibliotekanauki.pl/articles/233941.pdf
Data publikacji:
2015
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
pneumatic compact spinning
blend yarn
hamilton index method
high speed camera
pneumatyczne przędzarki kompaktowe
mieszankowe przędze
Metoda indeksu Hamiltona
szybkobieżna kamera cyfrowa
Opis:
Pneumatic compact spinning is the most widely used compact spinning technology at present, which is implemented by using negative airflow to condense the fibre bundle and decrease the spinning triangle. Roller-type and Lattice apron-type compact spinning are two major kinds of pneumatic compact spinning now. In this paper, blend yarn qualities spun by one kind of roller-type compact spinning: complete condensing spinning (CCS), and one kind of Lattice apron-type compact spinning: 4-line rollers compact spinning (FRCS) were studied and analysed comparatively. First, 28.1, 18.5 and 12.3 tex JC60/T40 blend yarns and 18.5, 14.8 and 11.8 tex JC35/T65 blend yarns were spun on two kinds of compact spinning systems, respectively, and the effects of the blending ratio on yarn qualities were discussed. Then another two kinds of cotton blended yarns - JC60/R40 and JC60/M40 were spun. 28.1, 18.5, 14.8 tex JC60/R40 and 18.5, 14.8, 11.8 tex JC60/M40 were spun on two kinds of compact spinning systems, respectively. Meanwhile the qualities of spun yarns were analysed by using two methods. First with a high speed camera system - OLYMPUS i-speed3 (OLYMPUS Image Co., Ltd., Japan), the condensing process of a fibre strand in the condensing zones were captured and analysed. Second the cross sections of the spun yarns were presented using a Y172 Hardy’s thin cross-section sampling device (Nantong Hongda Experiment Instruments Co., Ltd., China). The corresponding Hamilton Index was then calculated, and the fibre radial distributions in the yarn cross section were analysed. The results show that the fibre condensing effects are increased with an increase in the ratio of cotton fibre on the blended yarn for both kinds of compact spinning, especially the FRCS. Meanwhile with an increase in the ratio of polyester fibre on the blended yarn, the advantage of CCS with respect to yarn qualities increased. For both JC60/R40 and JC60/M40, cotton fibres are transferred to the outer part of the yarn body. However, the fibres in JC60/R40 yarn spun by CCS and those in JC60/M40 yarn spun by FRCS are distributed more randomly.
Przędzenie kompaktowe realizowane na zmodyfikowanych przędzarkach obrączkowych jest obecnie najbardziej rozpowszechnioną techniką przędzalniczą, która została wprowadzona na skalę przemysłową dzięki wykorzystaniu podciśnienia mającego na celu zagęszczenie przetwarzanego w przędzę strumienia włókien oraz zmniejszenie trójkąta przędzenia. Celem prezentowanych przez autorów badań była ocena porównawcza jakości i struktury przędz kompaktowych wytworzonych dwoma systemami kompaktowania. Przedstawiono wyniki badań jakości przędz obrączkowych kompaktowych mieszankowych. Przędze te wyprzędziono z mieszanek bawełny z włóknami poliestrowymi o udziale 65/35, mieszanek bawełny z jedwabiem celulozowym o udziale 60/40 oraz mieszanek bawełny z modalnymi włóknami wiskozowymi o udziale 60/40. Wytworzone przędze analizowano dwoma różnymi metodami. Pierwsza metoda polegała na rejestrowaniu za pośrednictwem szybkobieżnej kamery cyfrowej procesu zagęszczania tasiemki włókien w strefie jej zagęszczania, a następnie analizowaniu struktury tworzącej się przędzy. W drugiej metodzie sporządzano, przy pomocy stanowiska pomiarowego wyposażonego w urządzenie przeznaczone do pobierania próbek oraz mikroskopu, obrazy przekrojów poprzecznych wytworzonych przędz, a także obliczano odpowiednio wskaźniki migracji włókien w przekroju poprzecznym przędzy reprezentowane przez indeksy Hamiltona.
Źródło:
Fibres & Textiles in Eastern Europe; 2015, 6 (114); 55-67
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nonlinear degradation modeling and maintenance policy for a two-stage degradation system based on cumulative damage model
System charakteryzujący się dwuetapowym procesem degradacji: nieliniowe modelowanie degradacji oraz wyznaczanie strategii eksploatacji systemu na podstawie modelu sumowania uszkodzeń
Autorzy:
Ni, X.
Zhao, J.
Song, W.
Guo, C.
Li, H.
Powiązania:
https://bibliotekanauki.pl/articles/301523.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
two-stage
nonlinear
degradation modeling
cumulative damage model
maintenance policy
dwu-etapowy
nieliniowy
modelowanie degradacji
model sumowania uszkodzeń
strategia eksploatacji
Opis:
This paper attempts to take into account a two-stage degradation system which degradation rate is non-stationary and change over time. The system degradation is thought to be caused by shocks, and system degradation model is established based on cumulative damage model. The nonlinear degradation process is expressed by different shock damage and shock counting. And shock damage and shock counting are assumed to be Gamma distribution and non-homogeneous Poisson process, respectively. On the basis of these, system reliability model and nonlinear degradation model are given. In order to optimal maintenance policy for considered system, adaptive maintenance policy and time-dependent maintenance policy are studied, and mean maintenance cost rate is established to evaluate the maintenance policies. Numerical examples are given to analyze the influences of degradation model parameters and find optimal maintenance policy for considered system.
W przedstawionym artykule badano system, w którym proces degradacji zachodzi dwuetapowo, a szybkość degradacji jest zmienna w czasie. Przyjęto, że do degradacji systemu dochodzi w wyniku wstrząsów. Model degradacji systemu oparto na modelu sumowania uszkodzeń. Nieliniowy proces degradacji określono jako taki, w którym uszkodzenie powodowane wstrząsem oraz częstotliwość wstrząsów są wartościami zmiennymi. Przyjęto, że uszkodzenie powodowane wstrząsem ma rozkład gamma a częstotliwość wstrząsów jest niejednorodnym procesem Poissona. Na tej podstawie utworzono model niezawodności systemu oraz model degradacji nieliniowej. W celu opracowania optymalnej strategii eksploatacji dla rozpatrywanego systemu, rozważono dwa typy strategii utrzymania ruchu: strategię adaptacyjną oraz strategię czasowo-zależną. Strategie te oceniano określając średni poziom kosztów eksploatacji. Przykłady numeryczne posłużyły do analizy wpływu parametrów modelu degradacji oraz pozwoliły określić optymalną strategię utrzymania dla rozpatrywanego systemu.
Źródło:
Eksploatacja i Niezawodność; 2016, 18, 2; 171-180
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Three Insensitive Energetic Co-crystals of 1-Nitronaphthalene, with 2,4,6-Trinitrotoluene (TNT), 2,4,6-Trinitrophenol (Picric Acid) and D-Mannitol Hexanitrate (MHN)
Autorzy:
Hong, D.
Li, Y.
Zhu, S.
Zhang, L.
Pang, C.
Powiązania:
https://bibliotekanauki.pl/articles/1063066.pdf
Data publikacji:
2015
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
co-crystal
insensitive energetic material
crystal structure
explosive properties
Opis:
Co-crystallization is proposed as an effective method to alter the physicochemical properties of energetic materials, e.g. density, sensitivity and solubility. As reported in this paper, it was found that 1-nitronaphthalene could form cocrystals with TNT, picric acid and MHN in a 1:1 molecular ratio. The sensitivity and thermal stability of the 1-nitronaphthalene co-crystals was greatly improved compared with that of pure TNT, picric acid and MHN. In addition, the melting points of TNT, picric acid and MHN were lowered through co-crystallization with 1-nitronaphthalene. The electrostatic potential surface of 1-nitronaphthalene, calculated by the DFT method, showed that the electron-rich 1-nitronaphthalene has a tendency to be a proton donor and to co-crystallize with other energetic materials. The structures of the co-crystals of 1-nitronaphthalene with TNT and picric acid were characterized by single crystal X-ray diffraction (SXRD). The 1-nitronaphthalene/MHN co-crystal was studied by powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC) and FTIR.
Źródło:
Central European Journal of Energetic Materials; 2015, 12, 1; 47-62
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dynamic-accumulative operation policy of continuous distillation for the purification of anisole
Autorzy:
Wang, Z.
Li, S.
Wang, C.
Guo, X.
Bai, P.
Powiązania:
https://bibliotekanauki.pl/articles/779622.pdf
Data publikacji:
2016
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
anisole recycling
dynamic-accumulative operation policy
continuous distillation
simulation
Opis:
In the B10 isotope enrichment industry, the purification of anisole mixture makes great sense. A dynamic-accumulative operation policy of continuous distillation (DACD) with repeated filling and dumping of the still is proposed for the separation of trace heavy impurities in the recycled anisole. To simulate and optimize the purification process of anisole, a mathematical model of DACD is derived, and the computer codes are developed in the MATLAB environment. Moreover, the experiment is performed in a pilot-scale distillation column. The results show that the experimental date agrees well with simulation results. DACD could solve the difficulty of flow rate control when the bottom flow rate is very small in continuous distillation. The size of the still in this operation mode is also smaller than that in batch distillation. And the yield of anisole is raised to 99.91%. In a word, DACD is especially suitable for separating trace heavy impurities from the recycled anisole.
Źródło:
Polish Journal of Chemical Technology; 2016, 18, 1; 33-39
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Traffic fatalities prediction based on support vector machine
Autorzy:
Li, T.
Yang, Y.
Wang, Y.
Chen, C.
Yao, J.
Powiązania:
https://bibliotekanauki.pl/articles/223743.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
traffic accident
support vector machine
SVM
particle swarm optimization (PSO)
PSO
prediction model
optimal parameters
wypadek drogowy
Particle Swarm Optimization
model prognostyczny
optymalne parametry
Opis:
To effectively predict traffic fatalities and promote the friendly development of transportation, a prediction model of traffic fatalities is established based on support vector machine (SVM). As the prediction accuracy of SVM largely depends on the selection of parameters, Particle Swarm Optimization (PSO) is introduced to find the optimal parameters. In this paper, small sample and nonlinear data are used to predict fatalities of traffic accident. Traffic accident statistics data of China from 1981 to 2012 are chosen as experimental data. The input variables for predicting accident are highway mileage, vehicle number and population size while the output variables are traffic fatality. To verify the validity of the proposed prediction method, the back-propagation neural network (BPNN) prediction model and SVM prediction model are also used to predict the traffic fatalities. The results show that compared with BPNN prediction model and SVM model, the prediction model of traffic fatalities based on PSO-SVM has higher prediction precision and smaller errors. The model can be more effective to forecast the traffic fatalities. And the method using particle swarm optimization algorithm for parameter optimization of SVM is feasible and effective. In addition, this method avoids overcomes the problem of “over learning” in neural network training progress.
Źródło:
Archives of Transport; 2016, 39, 3; 21-30
0866-9546
2300-8830
Pojawia się w:
Archives of Transport
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rare Earth Elements supply vs. clean energy technologies: new problems to be solve
Dostawy pierwiastków ziem rzadkich (REE) a czyste technologie energetyczne: nowe problemy do rozwiązania
Autorzy:
Zhou, B.
Li, Z.
Zhao, Y.
Zhang, C.
Wei, Y.
Powiązania:
https://bibliotekanauki.pl/articles/216173.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Instytut Gospodarki Surowcami Mineralnymi i Energią PAN
Tematy:
rare earth element
clean energy technology
supply chain
pierwiastki ziem rzadkich
czysta technologia energetyczna
łańcuch dostaw
Opis:
Rare earth elements (REEs) provide important properties to clean energy technologies such as wind turbine and hybrid electric vehicles. The global REE demand will grow rapidly during the global transformation toward a greener economy in the next decades. This high demand will require a steady supply chain in the long run. China has a monopoly of global REE production and extraction. The global REE supply chain runs the risk of disruption along with Chinese REE policy evolution. To overcome this supply chain vulnerability, new strategies and measures should be adopted to satisfy future REE supply/demand. There is a pressing need to explore REE deposits, develop efficient REE recycling techniques from end-of-life products, improve substitution technologies for REEs, and reduce the number of critical REEs used in devices. Such measures are facing significant challenges due to environmental factors and an unbalanced market, and overcoming them requires efforts from government and REE companies.
Pierwiastki ziem rzadkich (Rare Earths Elements) mają istotne znaczenie dla rozwoju czystych technologii energetycznych, takich jak turbiny wiatrowe czy pojazdy hybrydowe. Światowy popyt na REE będzie wzrastał w związku z globalną transformacją w kierunku bardziej czystej (ekologicznej) gospodarki w okresie najbliższych dziesięcioleci. Wysoki popyt wymagać będzie stabilnego łańcucha dostaw REE w dłuższej perspektywie. Chiny mają monopol w zakresie globalnej produkcji i wydobycia REE. Światowe dostawy REE obarczone są jednak ryzykiem zakłóceń wynikających z chińskiej polityki w tym zakresie. W związku z tym, powinny być przyjęte nowe środki i strategie w celu zaspokojenia przyszłego popytu/podaży na REE. Istnieje pilna konieczność: poszukiwania nowych złóż, opracowania skutecznych technik recyklingu z wycofanych z eksploatacji produktów, poprawy technologii z zastosowaniem substytutów REE oraz zmniejszenie liczby krytycznych pierwiastków ziem rzadkich w stosowanych urządzeniach. Działania te stanowią poważne wyzwanie ze względu na czynniki środowiskowe i niezrównoważony rynek (monopol podaży). Przezwyciężenie ich wymaga odpowiednich działań ze strony rządu i firm zajmujących się produkcją REE.
Źródło:
Gospodarka Surowcami Mineralnymi; 2016, 32, 4; 29-44
0860-0953
Pojawia się w:
Gospodarka Surowcami Mineralnymi
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Insensitive Booster Explosive: DAAF Surface-coated with Viton A
Autorzy:
Li, X.
Wu, B.
Liu, S.
An, C.
Wang, J.
Powiązania:
https://bibliotekanauki.pl/articles/358841.pdf
Data publikacji:
2018
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
DAAF
refinement
surface-coated
thermal analysis
impact sensitivity
Opis:
3,3’-Diamino-4,4’-azoxyfurazan (DAAF) is the principal component of an insensitive booster explosive; refined DAAF and DAAF surface-coated with Viton A were prepared. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and differential scanning calorimetry (DSC) were employed to characterize the morphology, composition, and thermal decomposition of these samples. The impact sensitivity and theoretical detonation velocity of DAAF-based composites were also measured and analyzed. The results showed that DAAF surface-coated with Viton A was successfully obtained, and the impact sensitivity of DAAF/Viton A composites was much lower than that of crude DAAF. In addition, DAAF/Viton A composites exhibited better thermal stability compared to crude DAAF and refined DAAF. The theoretical detonation velocity of DAAF/Viton A composites and TATB/Viton A composites are roughly the same. Therefore, there is still great potential for DAAF to be used as the main explosive component of a booster explosive.
Źródło:
Central European Journal of Energetic Materials; 2018, 15, 3; 445-455
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
EGTA, a calcium chelator, affects cell cycle and increases DNA methylation in root tips of Triticum aestivum L.
Autorzy:
Zhang, C.
Shi, W.
Ma, K.
Li, H.
Zhang, F.
Powiązania:
https://bibliotekanauki.pl/articles/57455.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Botaniczne
Opis:
In this study, when germinated Triticum aestivum L. seeds were treated with 0, 2, 4 and 6 mM ethyl glycol tetraacetic acid (EGTA), root growth was suppressed and the mitotic index decreased. These inhibitory effects were positively correlated with EGTA concentration. RT-PCR analysis revealed that the expression of several gene markers related to the G1/S transition of the cell cycle were significantly downregulated. Confocal microscopy of Fluo-3/AM-stained roots showed chelation of nearly all of the Ca2+ within the root meristematic regions. Both random amplified polymorphic DNA (RAPD) and coupled restriction enzyme digestion-random amplification (CRED-RA) techniques showed significant increases in the levels of genomic DNA polymorphisms and degree of DNA methylation. The study provides information concerning the impact of Ca²+) chelator, EGTA, on the growth, expression of cell cycle transition marker genes, and changes in DNA structure and methylation in the wheat roots.
Źródło:
Acta Societatis Botanicorum Poloniae; 2016, 85, 3
0001-6977
2083-9480
Pojawia się w:
Acta Societatis Botanicorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research of lateral force of pipe conveyor belt’s vertical transport section
Autorzy:
Wang, S.
Guo, Y.-C.
Li, D. Y.
Hu, K.
Powiązania:
https://bibliotekanauki.pl/articles/223504.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
pipe belt conveyor
vertical transport
lateral force
discrete element simulation
experimental verification
przenośnik taśmowy
transport pionowy
siła boczna
symulacja
platforma doświadczalna
Opis:
In order to release the lateral force of pipe conveyor belt in vertical transportation, the thesis had a study of the lateral force of the conveyor belt. By making use of Janssen Principles and fractal theory, based on reasonable simplification, the author established a mathematical model of the lateral force in vertical transportation, and with the research foundation of the pipe belt conveyor for underground transportation, through solution analysis, the author found out that the change of material diameter would lead to nonlinear variation of the lateral force of the conveyor belt. Under the circumstances of different material diameter, discrete element method was adopted to simulate the lateral force of the conveyor belt, thus working out the distribution curve chart of the lateral force. To verify the reliability of the theory, the author built an experimental platform for pipe conveyor belt in vertical transportation, and experimented with five groups of materials in different diameter, working out the strain of lateral force of the characteristic conveyor belt; by comparing the theoretical result, the simulation result and the experimental result, it showed that the solution to relieving lateral force through optimization selection of material diameter put forward in this thesis was reasonable and effective. It provides theoretical reference for the design of pipe belt conveyor.
Źródło:
Archives of Transport; 2016, 37, 1; 67-75
0866-9546
2300-8830
Pojawia się w:
Archives of Transport
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ethnobotanical study on medicinal plants used by Li people in Ledong, Hainan Island, China
Autorzy:
Huang, W.
Li, P.
Liu, Y.
Ju, Y.
Wang, J.
Ntumwel, C.B.
Long, C.
Powiązania:
https://bibliotekanauki.pl/articles/57864.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Botaniczne
Tematy:
ethnobotany
traditional knowledge
ethnomedicine
medicinal plant
Li ethnic group
ethnic group
Ledong county
Hainan Island
China
Opis:
The paper documents on the uses of traditional medicinal plants used for treating human ailments in three villages of Ledong, a county inhabited by Liethnic group in the southwest of Hainan Province, China. Semi-structured interviews, key informant interviews and participatory observations were used to collect ethnobotanical data from February to March 2012 and in July 2013. The data collected was analyzed using descriptive statistics. Thirty native knowledgeable people were interviewed. The Li community uses 50 plant species in 36 families for medicinal purposes. The most common medicinal plant families were Leguminosae (14%), Compositae (6%), and Euphorbiaceae (6%), and the most common preparations methods were decoction (84%), crushing (38%), and poultice (34%). The traditional medicinal plants were mainly used for hemostasis (12.9%), body pains (11.4%), gastrointestinal disorders (11.4%), and trauma (10%). Twenty-four species of medicinal plants (48%) have never been reported in the literature of Li medicines. In addition, 22 species (44%) have already been studied by researchers and their extracts or compounds were good bioactives. However, the rapid socioeconomic development in the county is the main threat to the conservation of Li medicine and has resulted in the decrease in the abundance and use of medicinal plants and associated traditional knowledge. Other factors accounting for a decrease in the use of Li medicinal plants like loss of plant diversity, change of land use, and threatened traditional knowledge were equally discussed.
Źródło:
Acta Societatis Botanicorum Poloniae; 2016, 85, 1
0001-6977
2083-9480
Pojawia się w:
Acta Societatis Botanicorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pharmacokinetics of diclofenac sodium injection in swine
Autorzy:
Yang, H.F.
Li, Y.J.
Li, Y.Y.
Huang, C.
Huang, L.X.
Bu, S.J.
Powiązania:
https://bibliotekanauki.pl/articles/2087550.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
diclofenac sodium injection
pharmacokinetics
bioavailability
swine
HPLC
Źródło:
Polish Journal of Veterinary Sciences; 2019, 2; 423-426
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Production of intergeneric allotetraploid between autotetraploid non-heading Chinese cabbage (Brassica campestris ssp. chinensis Makino) and autotetraploid radish (Raphanus sativus L.)
Autorzy:
Sun, C.-Z.
Li, Y.
Zhang, S.-N.
Zheng, J.-S.
Powiązania:
https://bibliotekanauki.pl/articles/56661.pdf
Data publikacji:
2014
Wydawca:
Polskie Towarzystwo Botaniczne
Tematy:
intergeneric allotetraploid
autotetraploid
non-heading cabbage
Chinese cabbage
Brassica campestris ssp.chinensis
radish
Raphanus sativus
embryo culture
simple sequence repeat
Opis:
Intergeneric hybrids between non-heading Chinese cabbage (Brassica campestris ssp. chinensis Makino; 2n = 4x = 40) and radish (Raphanus sativus L.; 2n = 4x = 36) were obtained through ovary culture and embryo rescue. Some hybrid embryos (0.11 per ovary) were produced, but only 4 of them germinated. As most hybrid embryos failed to develop into plantlets directly, plants were regenerated by inducing shoots on the cultured cotyledon and inducing roots on the root induction medium. All hybrid plants were morphologically uniform. They resembled the non-heading Chinese cabbage in the long-lived habit, the plant status, the vernalization requirement and the petiole color, while the petiole shape, leaf venation pattern and flowers were more similar to those of radish. Upon examination of the flowers, these were found to have normal pistil, but rudimentary anthers with non-functional pollen grains. The somatic chromosome number of F1 plants was 38. Analysis of SSR banding patterns provided additional confirmation of hybridity.
Źródło:
Acta Societatis Botanicorum Poloniae; 2014, 83, 1
0001-6977
2083-9480
Pojawia się w:
Acta Societatis Botanicorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A numerical upper bound formulation with sensibly-arranged velocity discontinuities and orthotropic material strength behaviour
Autorzy:
Li, M.
Füssl, J.
Lukacevic, M.
Eberhardsteiner, J.
Martin, C. M.
Powiązania:
https://bibliotekanauki.pl/articles/279886.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
numerical upper bound formulations
localised failure modes
traction-based yield function
sensible arrangement of velocity discontinuities
orthotropic material strength behaviour
Opis:
Numerical limit analysis allows for fast estimates of the collapse load of structures exhibiting ideal plastic material behaviour. In numerical upper bound formulations, the description of the unknown velocity field can be extended by introducing velocity discontinuities between finite elements. Through these additional degrees of freedom, localised failure modes may be approximated more accurately and better upper bounds can be obtained. In the existing formulations, such discontinuities are typically introduced between all elements and the description is restricted to isotropic failure behaviour. In this work, a general 3D upper bound formulation is briefly proposed, allowing the consideration of both isotropic and orthotropic yield functions within finite elements as well as at velocity discontinuities. The concept of “projecting” a stress-based orthotropic yield function onto a certain discontinuity is presented, giving a traction-based yield function which allows for a consistent description of the material strength behaviour across the interface. The formulation is verified by means of two classical examples, the rigid strip footing and the block with asymmetric holes. Furthermore, based on the computation of potential orientations of plastic flow localisation, a simple concept for a sensible arrangement of velocity discontinuities is proposed. It is shown that this concept performs very well for isotropic as well as anisotropic material strength behaviour. A feature of the present work is that, velocity jumps are allowed only across the prescribed finite element interfaces determined from the sensible discontinuity arrangement. Good upper bounds similar to those in the existing works are obtained with far fewer degrees of freedom.
Źródło:
Journal of Theoretical and Applied Mechanics; 2018, 56, 2; 417-433
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Different Ignition Responses of Powdery and Bulky 1,3,5-Triamino-2,4,6-trinitrobenzene (TATB) Based Polymer-bonded Explosives under Ultra-high Voltage Electrostatic Discharge
Autorzy:
Lyu, Z.
Long, X.
Li, Z.
Dai, X.
Deng, C.
He, S.
Li, M.
Yao, K.
Wen, Y.
Powiązania:
https://bibliotekanauki.pl/articles/358240.pdf
Data publikacji:
2018
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
electrostatic spark sensitivity
ultra-high voltage electrostatic discharge
thermal effect
electric field effect
Opis:
The electric spark induced ignition mechanism for explosives needs further study. The ignition of powdery and bulky TATB by electrostatic discharge (ESD) was investigated. Up to 200 kV ultra-high voltage ESD was applied to powdery and bulky explosives of two TATB-based polymer-bonded explosives (named PBX-1 and PBX-2). The results showed that the spark sensitivities of powdery and bulky explosives are extremely different for the same formulation. The 50% ignition voltages of powdery PBX-1 and PBX-2 were 10.8 kV and 8.5 kV, respectively, while the values for the bulky samples (tablets) were not less than 200 kV. Both heat and the electric field can be transmitted into the powdery samples, on the other hand only the electric field can be transmitted into the bulk samples. The electric field has a smaller contribution while the heat has a larger contribution to the ignition during an ESD, i.e., the thermal effect plays a main role in the ignition process. Our experimental results are in good agreement with recent results calculated by density functional theory.
Źródło:
Central European Journal of Energetic Materials; 2018, 15, 2; 283-298
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A novel Wiener process model with measurement errors for degradation analysis
Analiza degradacji z zastosowa niem nowego modelu procesu Wienera uwzględniającego błędy pomiarowe
Autorzy:
Wang, Z.
Li, J.
Zhang, Y.
Fu, H.
Liu, C.
Krishnaswamy, S.
Powiązania:
https://bibliotekanauki.pl/articles/301209.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
performance degradation
independent increment process
Wiener process model
linear mean function
linear standard deviation function
measurement error
obniżenie charakterystyk
proces o przyrostach niezależnych
model procesu Wienera
funkcja średniej liniowej
funkcja liniowego odchylenia standardowego
błąd pomiaru
Opis:
Degradation analysis can be used to assess reliability for complex systems and highly reliable products, because few or even no failures are expected in a reasonable life test span. In order to further our study on degradation analysis, an independent increment random process method with linear mean and standard deviation functions is presented to model practical degradation procedures. It is essentially a Wiener process method. Since measurement errors are often created by imperfect instruments, procedures and environments during degradation investigation, the measurement error is incorporated into the independent increment random process. Furthermore, statistical inferences of this model are discussed, and close forms of a product’s median life and percentile of the failure time distribution (FTD) are also derived. The proposed method is illustrated and verified in a comprehensive simulation study and two practice applications for storage disks and Infrared light-emitting diodes. Meanwhile, the time-transformed Wiener process model with measurement error is considered as a reference method. Comparisons show that the proposed model can provide reasonable results, even in considerably small sample size circumstance.
Analizę degradacji można stosować do oceny niezawodności wysoce niezawodnych złożonych systemów i produktów, ponieważ w ich przypadku istnieje bardzo niskie lub zerowe prawdopodobieństwo wystąpienia uszkodzenia w trakcie badania trwałości w przyjętym okresie eksploatacji. W artykule przedstawiono nowo opracowane podejście do modelowania procesu degradacji wykorzystujące metodę procesu o przyrostach niezależnych oraz pojęcia funkcji średniej liniowej i funkcji liniowego odchylenia standardowego. Zasadniczo jest to metoda oparta na procesie Wienera. Ponieważ badania degradacji często wiążą się z błędami pomiarowymi wynikającymi z niedoskonałości stosowanych narzędzi, procedur i warunków badawczych, opisywany proces o przyrostach niezależnych uwzględnia błędy pomiaru. Ponadto, w pracy omówiono wnioski statystyczne, jakie można wyciągnąć na podstawie przedstawionego modelu oraz wyprowadzono wzory ogólne na średnią długość życia produktu oraz na percentyl rozkładu czasu do uszkodzenia. Proponowaną metodę zilustrowano i zweryfikowano na podstawie kompleksowego badania symulacyjnego oraz przykładów praktycznego zastosowania modelu w odniesieniu do dysków pamięci masowej oraz diod podczerwieni. W artykule przedstawiono także model procesu Wienera z transformowanym czasem uwzględniający błąd pomiaru, który posłużył za model referencyjny. Porównania pokazują, że proponowany model może dawać poprawne wyniki, nawet przy bardzo małej liczebności próby.
Źródło:
Eksploatacja i Niezawodność; 2016, 18, 3; 396-405
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ubiquitiform in applied mechanics
Autorzy:
Ou, Z.-C.
Li, G.-Y.
Duan, Z.-P.
Huang, F-L.
Powiązania:
https://bibliotekanauki.pl/articles/279395.pdf
Data publikacji:
2014
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
ubiquitiform
fractal
Hausdorff dimension
Opis:
We demonstrate that a physical object in nature should not be described as a fractal, despite an ideal mathematical object, rather a ubiquitiform (a terminology coined here for a finite order self-similar or self-affine structure). It is shown mathematically that a ubiquitiform must be of integral dimension, and that the Hausdorff dimension of the initial element of a fractal changes abruptly at the point at infinity, which results in divergence of the integral dimensional measure of the fractal and makes the fractal approximation to a ubiquitiform unreasonable. Therefore, instead of the existing fractal theory in applied mechanics, a new type of ubiquitiformal one is needed.
Źródło:
Journal of Theoretical and Applied Mechanics; 2014, 52, 1; 37-46
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Growth of β-$Ga_2O_3$ Nanorods and Photoluminescence Properties
Autorzy:
Zhang,, S.
Zhuang, H.
Xue, C.
Li, B.
Shen, J.
Wang, D.
Powiązania:
https://bibliotekanauki.pl/articles/1814023.pdf
Data publikacji:
2007-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
68.65.-k
79.60.Jv
81.15.Cd
Opis:
β-$Ga_2O_3$ nanorods were successfully fabricated through annealing $Ga_2O_3$/Mo films deposited on the Si (111) substrate by radio frequency magnetron sputtering technique. The morphology and structure of the as-synthesized nanorods were characterized by X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, and energy dispersive X-rays spectroscopy. The results show that the formed nanorods are single-crystalline $Ga_2O_3$ with monoclinic structure. The diameters of nanorods are 200 nm and lengths typically up to several micrometers. A photoluminescence spectrum at room temperature under excitation at 325 nm exhibits two strong blue-light peaks located at about 413.0 nm and 437.5 nm, attributed to the recombination of bound electron-hole exciton in β-$Ga_2O_3$ single crystal. The growth process of the β-$Ga_2O_3$ nanorods is probably dominated by conventional vapor-solid mechanism.
Źródło:
Acta Physica Polonica A; 2007, 112, 6; 1195-1201
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Flotation of long flame coal pretreated by polyoxyethylene sorbitan monostearate
Autorzy:
Ni, C.
Xie, G.
Li, Z.
Bu, X.
Peng, Y.
Sha, J.
Powiązania:
https://bibliotekanauki.pl/articles/110299.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
flotation
hydrophobicity
low rank coal
Tween 60
pretreatment
Opis:
In this investigation, polyoxyethylene sorbitan monostearate (Tween 60) was used to improve flotation of fine long flame coal. The flotation recovery of long flame coal could be increased when long flame coal was either pretreated or conditioned with Tween 60 in a flotation cell for a period before the addition of collector. Fourier Transform Infrared (FTIR) technique was used to indicate surface properties of long flame coal. The results of FTIR show that there are many oxygen functional groups on the sur-face. Contact angle measurements were used to indicate changes in hydrophobicity of coal surface before and after Tween 60 and/or diesel pretreatments. The results of contact angle measurements show that hydrophobicity of coal can be increased by Tween 60. Tween 60 can also enhance adsorption of diesel on the coal surface, and hence floatability of long flame coal can be further improved. Tween 60 primarily enhances the flotation recovery of low density coal fractions (<1.5 and 1.5-1.8 kg/dm3). However, the increase in flotatation recovery is less significant with an excessive addition of Tween 60.
Źródło:
Physicochemical Problems of Mineral Processing; 2016, 52, 1; 317-327
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of silicon and calcium application on growth, yield and fruit quality parameters of cucumber established in a sodic soil
Autorzy:
González-Terán, G.E.
Gómez-Merino, F.C.
Trejo-Téllez, L.I.
Powiązania:
https://bibliotekanauki.pl/articles/12714269.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Przyrodniczy w Lublinie. Wydawnictwo Uniwersytetu Przyrodniczego w Lublinie
Opis:
Soil salinity is a growing problem that affects crop quality. Cucumber is a vegetable eaten fresh, with great worldwide demand, making its chemical and physical characteristics important. In the present work, the effects of foliar application of silicon (Si: 0 and 2 mM), calcium (Ca: 0 and 2 mM), and the combination of both (Si + Ca: 0 + 0 mM, 2 + 0 mM, 0 + 2 mM and 2 + 2 mM) on dry matter of leaves and stems, yield and fruit quality of cucumbers grown in a sodic soil were studied. Treatments did not affect dry biomass, yield and product size. The obtained results show that applying foliar Ca increases total soluble solids in comparison to the control. Foliar Si application significantly increased fruit firmness in the end towards the peduncle. Moreover, foliar Ca application increased the fruit hue angle (intense green), while foliar Si application increased chroma (dark green), both significantly regarding the control. The individual applications of Si and Ca were proven to differentially improve the fruit quality parameters of cucumber in sodic soil conditions.
Źródło:
Acta Scientiarum Polonorum. Hortorum Cultus; 2020, 19, 3; 149-158
1644-0692
Pojawia się w:
Acta Scientiarum Polonorum. Hortorum Cultus
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Theoretical analysis of a hollow laser beam transmitting in an off-axis Cassegrain optical antenna system
Autorzy:
Mi, C
Jiang, P
Yang, H.
Ke, S
Li, B
Liu, J.
Powiązania:
https://bibliotekanauki.pl/articles/174358.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
Cassegrain optical antenna
off-axis hollow laser beam
receiving efficiency
Opis:
The optical model of a Cassegrain optical antenna with a confocal double-parabolic reflector structure has been designed, and the propagation characteristics of a hollow laser beam, which could avoid the loss of energy caused by the subreflector center reflection in the optical antenna, has been researched in this paper. By detailed analysis and numerical calculations of a receiving Cassegrain antenna with different deflection angles, the coupling efficiency curve and 3-D distributions of the receiving light intensity for different inclined angles have been obtained.
Źródło:
Optica Applicata; 2014, 44, 3; 421-431
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation of Al Nanoparticles and Their Influence on the Thermal Decomposition of RDX
Autorzy:
Hou, C.
Geng, X.
An, Ch.
Wang, J.
Xu, W.
Li, X.
Powiązania:
https://bibliotekanauki.pl/articles/358260.pdf
Data publikacji:
2013
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
Al nanoparticles
properties
RDX
thermal decomposition
Opis:
Aluminum (Al) nanoparticles were prepared by the DC arc plasma method in order to study the influence of Al nanoparticles on the thermal decomposition of cyclotrimethylenetrinitramine (RDX). The Al powder was characterized by TEM, BET, XRD, and LSA, and the thermal decomposition of RDX and RDX/nanometer Al were examined by DSC. Based on the DSC curves, the thermal decomposition parameters of the samples were calculated and compared. The results showed that the particles of Al are homogeneous and fine, and that the surface is smooth. The TEM results showed that the nanoparticles are spherical, with an average diameter of approximately 60 nm. The peak temperature of RDX decomposition decreased by 4.36 K at the heating rates of 5, 10, and 20 K/min after the addition of nano-Al powder, and the activation energy for decomposition decreased by about 11 kJ/mol. Furthermore, the critical explosion temperature was also reduced. These observable changes indicate that Al nanoparticles act as catalysts for the thermal decomposition of RDX.
Źródło:
Central European Journal of Energetic Materials; 2013, 10, 1; 123-133
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improving Triggering Characteristics for a Surface-Flashover Triggered Vacuum Switch
Autorzy:
He, Z.
Wang, L.
Li, F.
Yao, W.
Dong, M.
Zhao, C.
Powiązania:
https://bibliotekanauki.pl/articles/1807889.pdf
Data publikacji:
2009-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
52.80.Vp
52.75.Kq
52.25.Mq
Opis:
A surface-breakdown triggered vacuum switch with parallel disk electrodes and semiconductor surface flashover trigger electrode has many advantages, it is easy to be triggered and machined. The resistance of the trigger gap has been increased in terms of modifying the thickness of the semiconductor layer and improving coating process technology. The trigger gap resistance, trigger voltage and trigger waveforms were experimentally tested. The results show that the triggering characteristics can be improved by increasing the trigger resistance.
Źródło:
Acta Physica Polonica A; 2009, 115, 6; 1019-1021
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Recovery of Iron from Copper Slag by Carbothermic Reduction and Magnetic Separation in the Presence of CaO
Autorzy:
Chun, T.
Mu, G.
Di, Z.
Long, H.
Ning, C.
Li, D.
Powiązania:
https://bibliotekanauki.pl/articles/355597.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
copper slag
recovery of iron
carbothermic reduction
magnetic separation
Opis:
The carbothermic reduction of copper slag at the different binary basicity (CaO/SiO2 ) was carried out for recovering iron by wet magnetic separation. Calcium carbonate is found to be capable of improving the iron recovery, as well as increasing the particle size of metallic iron significantly. Experimental evidence showed that CaO reacted with SiO2 to form calcium silicate and FeO was liberated from the 2FeO.SiO2 , decreased the content of Fe in the slags, which improved the iron recovery during the magnetic separation. The final product, assaying 90.23%Fetotal (representing a metallization degree of 93.94%) and 0.58% Cu at the iron recovery of 85.70% was achieved at the basicity of 0.60, which can be briquetted as a burden material for weathering resistant steel making by electric arc furnace to replace part of scrap.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 1; 299-305
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Measurement of Surface Profile and Surface Roughness of Fibre-Optic Interconnect by Fast Fourier Transform
Autorzy:
Lin, C. S.
Yang, S. W.
Lin, H. L.
Li, J. W.
Powiązania:
https://bibliotekanauki.pl/articles/221117.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
surface profile
surface roughness
fibre end-face
fast Fourier transform
Opis:
This study proposes a surface profile and roughness measurement system for a fibre-optic interconnect based on optical interferometry. On the principle of Fizeau interferometer, an interference fringe is formed on the fibre end-face of the fibre-optic interconnect, and the fringe pattern is analysed using the Fast Fourier transform method to reconstruct the surface profile. However, as the obtained surface profile contains some amount of tilt, a rule for estimating this tilt value is developed in this paper. The actual fibre end-face surface profile is obtained by subtracting the estimated tilt amount from the surface profile, as calculated by the Fast Fourier transform method, and the corresponding surface roughness can be determined. The proposed system is characterized by non-contact measurement, and the sample is not coated with a reflector during measurement. According to the experimental results, the difference between the roughness measurement result of an Atomic Force Microscope (AFM) and the measurement result of this system is less than 3 nm.
Źródło:
Metrology and Measurement Systems; 2017, 24, 2; 381-390
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Inter-/Intra-Laminar Reinforced Hybrid Fibre Composites by Needle Punching and Thermal Bonding: Evaluation of Mechanical and Static Puncture Properties
Inter-/intra-laminarne wzmocnienie hybrydowych kompozytów włóknistych poprzez igłowanie i łączenie termiczne: Ocena mechanicznej i statycznej wytrzymałości na przebicie
Autorzy:
Li, T.-T.
Wang, R.
Lou, C.-W.
Pan, Y.-J.
Hsieh, C.-T.
Lin, J.-H.
Powiązania:
https://bibliotekanauki.pl/articles/234176.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
hybrid composite
needle punching
thermal bonding
puncture
recycle
hybrydowy materiał kompozytowy
igłowanie
spajanie termiczne
wytrzymałość na przebicie
recykling
Opis:
This study comparatively presents the static puncture property of different structures of intra-/inter-laminar reinforced hybrid composites via needle punching and thermal bonding techniques. The tensile and bursting properties of two composites with inter-laminar reinforcement by needle-punching and inter-and-intra- laminar reinforcement by both needle punching and using Kevlar fibres were also evaluated comparatively. The significance of process parameters including the low-melting PET fibre content, take-up speed of the punching machine, the plied orientation between the nonwoven and fabric and thermal bonding on the static puncture resistance was firstly investigated to seek out the significant parameters. The effects of significant processing parameters on static puncture and mechanical properties were explored afterwards. The research result shows that the plied orientation, low-melting PET content and thermal bonding affect the static puncture resistance most significantly. The maximum tensile strength and bursting strength occurred when hybrid composites after thermal bonding were composed of parallel-plied nonwovens and 90°-orientated glass fabric, as well as 70 wt% low-melting PET fibres. Recycled Kevlar fibre reinforcement dissipates additional static puncture resistance, and makes the static puncture resistance higher, as well as the tensile and bursting strengths for resultant hybrid fibre composites. Employing recycled Kevlar fibres is economical for the fabrication of hybrid composites. Diversified economical hybrid composites will be applied as a wall interlayer or garment interlining in the future.
Przedstawiono porównawcze omówienie statycznej wytrzymałości na przebicie różnych hybrydowych kompozytowych wzmocnionych struktur laminarnych. Badano wytrzymałość na rozciąganie i przerwanie różnych wariantów kompozytów zarówno igłowanych jak i łączonych termicznie, w tym takich, w których stosowano do wzmocnienia włókna Kevlar. Badano istotność wpływu różnych parametrów na statyczną wytrzymałość na przebicie. Stwierdzono znaczny wpływ orientacji igłowania i zawartości niskotopliwego PET.
Źródło:
Fibres & Textiles in Eastern Europe; 2016, 4 (118); 84-91
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An E-Bayesian method for reliability analysis of exponentially distributed products with zero-failure data
Metoda ba yesowskiej estymacji wartości oczekiwanej dla produktów o rozkładzie wykładniczym wykorzystująca dane o niezaistniałych uszkodzeniach
Autorzy:
Yin, Y.-C.
Huang, H.-Z.
Peng, W.
Li, Y.-F.
Mi, J.
Powiązania:
https://bibliotekanauki.pl/articles/301341.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
E-Bayesian estimation
exponential distribution
zero-failure data
failure rate
hierarchical Bayesian estimation
estymacja bayesowska wartości oczekiwanej
rozkład wykładniczy
dane o niezaistniałych uszkodzeniach
intensywność uszkodzeń
hierarchiczna estymacja bayesowska
Opis:
This paper investigate an E-Bayesian estimation as a reliability analysis method for the seekers to deal with the zero-failure life testing data. Firstly, we introduce an E-Bayesian estimation for the exponential distribution, and then propose a zero-failure model with assumptions. Using the proposed model, we set up a series of life tests for the seekers, and apply the E-Bayesian estimation on the observed zero-failure data to calculate the failure rate and reliability of the seekers. Finally, the reliability estimation results of the seekers demonstrate the performance of the proposed method.
W pracy analizowano estymację bayesowską wartości oczekiwanej jako metodę analizy niezawodności urządzeń naprowadzających w przypadkach, gdy dane z badań trwałości są danymi o uszkodzeniach niezaistniałych (zerowych). W pierwszej części pracy opisano E-estymację bayesowską dla rozkładu wykładniczego, a następnie zaproponowano model uszkodzeń niezaistniałych oraz opisano jego założenia. Wykorzystując zaproponowany model, zaprojektowano i zrealizowano serię badań trwałości urządzeń naprowadzających jak również zastosowano E-estymację bayesowską w celu obliczenia intensywności uszkodzeń oraz niezawodności badanych urządzeń. Wyniki oceny niezawodności urządzeń naprowadzających potwierdzają przydatność proponowanej metody.
Źródło:
Eksploatacja i Niezawodność; 2016, 18, 3; 445-449
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Posybilistyczna analiza niezawodnościowa systemu naprawialnego z pominiętym lub opóźnionym efektem uszkodzenia
Possibilistic reliability analysis of repairable system with omitted or delayed failure effects
Autorzy:
Pang, Y.
Huang, H. Z.
Xiao, N. C.
Liu, Y.
Li, Y. F.
Powiązania:
https://bibliotekanauki.pl/articles/301620.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
pominięty lub opóźniony efekt uszkodzenia
model Markowa
pominięcie czasu naprawy
posybilistyczna gotowość chwilowa
failure effect omitted or delayed
Markov model
repair time omission
instantaneous possibilistic availability
Opis:
Przy rozwiązywaniu problemów praktycznych w inżynierii przemysłowej można czasami pominąć bądź opóźnić efekt uszkodzenia jeśli ma on niewielki wpływ na system. Ściślej, wiodące cechy systemu można opisać w następujący sposób: 1) jeżeli czas naprawy jest wystarczająco krótki (krótszy niż pewna wartość progowa), tak iż nie ma on wpływu na działanie systemu, to można pominąć negatywny efekt uszkodzenia systemu. Przy takim czasie naprawy można uznać że system nie przerwał działania. Nazywa się go wtedy systemem z pominięciem czasu naprawy (pominięty efekt uszkodzenia). 2) Jeżeli czas naprawy jest dłuższy niż dana wartość progowa i efekt uszkodzenia staje się w końcu odczuwalny, to uznajemy, że system pozostawał aktywny od początkowego etapu naprawy aż do momentu, w którym został przekroczony próg czasu naprawy. Nazywa się go wtedy systemem z opóźnionym efektem uszkodzenia. W oparciu o powyższe dwie charakterystyki, wprowadzono w prezentowanej pracy model systemu naprawialnego. Omówiono dwa scenariusze, w których, odpowiednio, przyjęto, że wartość progowa jest wartością stałą lub nieujemną zmienną losową. Sformułowano wskaźniki niezawodnościowe, takie jak posybilistyczna gotowość chwilowa, dla systemu z pominiętym lub opóźnionym efektem uszkodzenia.
Within the practical problems in industrial engineering, the failure effect sometimes can be omitted or delayed if it has less effect on the system. In detail, the prominent features of the system can be described as follows: 1) if a repair time is sufficiently short (less than some threshold value) that does not affect the system operation, i.e. the pessimistic effect of system failure could be ignored. The system can be considered as operating during this repair time. It is called the system with repair time omission (failure effect omitted). 2) if a repair time is longer than the given threshold value and the failure effect is finally suffered. Then the system can be considered to remain operating from the initial stage of the repair till the end of the repair threshold. It is called the system with delayed failure effect. Based on the above two characteristics, model for the related repairable system is introduced in this paper. Two scenarios are discussed where the threshold value is regarded as a constant and non-negative random variable, respectively. Reliability indices such as instantaneous possibilistic availability are formulated for the system with failure effect omitted or delayed.
Źródło:
Eksploatacja i Niezawodność; 2012, 14, 3; 195-202
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Emerging of canine kobuvirus in dogsin China, 2015
Autorzy:
Liu, D.F.
Liu, X.
Li, Z.J.
F. Liu
Hu, X.L.
Li, Z.G.
Liu, C.G.
Ma, J.Z.
Powiązania:
https://bibliotekanauki.pl/articles/2087863.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
canine kobuvirus (CaKoV)
dogs
phylogenetic
VP1
China
Źródło:
Polish Journal of Veterinary Sciences; 2017, 4; 707-711
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multi-parameter measurement under fiber bending based on directional resonance coupling in photonic crystal fibers
Autorzy:
Tan, C.
Wang, Q.
Ding, Y.
Li, H.-W.
Wang, M.
Liu, H.
Powiązania:
https://bibliotekanauki.pl/articles/174320.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
fiber bending
multi-parameter measurement
photonic crystal fiber
fiber sensing
Opis:
A multi-parameter sensor with enhanced sensitivity based on magnetic fluids infiltrated photonic crystal fiber is proposed. The sensing performances are investigated using the mode coupling theory and finite element method. Four symmetrical defective channels are assembled into the photonic crystal fiber to produce two resonant transmission dips λCV and λCH in vertical and horizontal directions, respectively. Each dip can be split into two relatively shallow dips (λCV1, λCV2 or λCH1, λCH2) when the photonic crystal fiber is bent. Interestingly, the values of (λCH2 – λCH1) and (λCV2 – λCV1) are associated with corresponding bend-curvature but almost unaffected by external temperature or magnetic field. On the contrary, the values of (λCH2 + λCH1)/2 and (λCV2 + λCV1)/2 are sensitive to temperature or magnetic field regardless of the bending condition. Based on above characteristics and the dependence of the magnetic fluids refractive index on temperature and magnetic field, the proposed sensor can measure not only the bend-curvature and bend-direction, but also the temperature and magnetic field.
Źródło:
Optica Applicata; 2018, 48, 3; 449-462
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Theoretical Predictions of Lattice Parameters and Mechanical Properties of Pentaerythritol Tetranitrate under the Temperature and Pressure by Molecular Dynamics Simulations
Autorzy:
Tan, J.J.
Hu, C.
Li, Y.
Ge, N.
Chen, T.
Ji, G.
Powiązania:
https://bibliotekanauki.pl/articles/1033453.pdf
Data publikacji:
2017-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
molecular dynamics
lattice parameter
equation of state
elasticity
mechanical properties
Opis:
Molecular dynamics simulations with condensed-phase optimized molecular potentials for atomistic simulation studies force field are performed to investigate the structure, equation of state, and mechanical properties of high energetic material pentaerythritol tetranitrate. The equilibrium structural parameters, pressure-volume relationship and elastic constants at ambient conditions agree excellently with experiments. In addition, fitting the pressure-volume data to the Birch-Murnaghan or Murnaghan equation of state, the bulk modulus B₀ and its first pressure derivative B'₀ are obtained. Moreover, the elastic constants are calculated in the pressure range of 0-10 GPa at room temperature and in the temperature range of 200-400 K at the standard pressure, respectively. By the Voigt-Reuss-Hill approximation, the mechanical properties such as bulk modulus B, shear modulus G, and the Young modulus E are also obtained successfully. The predicted physical properties under temperature and pressure can provide powerful guidelines for the engineering application and further experimental investigations.
Źródło:
Acta Physica Polonica A; 2017, 131, 2; 318-323
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Defect Recovery in α-Fe e$\text{}^{-}$-irradiated at 300 K
Autorzy:
Dai, G. H.
Li, X. H.
Moser, P.
Moya, G.
Van Duysen, J. C.
Powiązania:
https://bibliotekanauki.pl/articles/1928989.pdf
Data publikacji:
1993-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.70.Bv
61.80.Fe
78.70.Bj
Opis:
Defect annealing recovery has been studied, by measuring positron lifetime spectra, in high-purity α-iron irradiated at 300 K with 3 MeV electrons to a fluency of 7 × 10$\text{}^{19}$ cm$\text{}^{-2}$. Vacancy clusters containing 6-10 single vacancies were observed immediately after irradiation during which they were possibly forming (the so-called "irradiation annealing"). With increasing temperature, the agglomerates continually grow in size at the expense of their concentration, giving rise to the formation of microvoids (> 15 vacancies). Also present were other types of defects, probably immobile vacancies trapped by impurity (e.g. carbon) atoms and dislocation/loops generated presumably from collapse of voids during the relatively high dose irradiation and/or the annealing. The immobile vacancies eventually became movable at around 350 K, supplying the growing clusters and thus leading to a stabilization in their concentration till around 500 K. Between 500 and 700 K, microvoids gradually evaporated, but the dislocation-associated defects were able to survive annealing at temperatures as high as 700 K. The void size and concentration and their evolution have been evaluated on the basis of both the to date theoretical and experimental studies. The temperature dependence was also, observed of positron trapping into vacancy agglomerates of various sizes.Za
Źródło:
Acta Physica Polonica A; 1993, 83, 3; 277-286
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of paclobutrazol on the growth and photosynthesis of Sequoia sempervirens seedlings
Autorzy:
Ju, S.
Xu, D.
Zhan, C.
Ji, L.
Yin, T.
Li, Z.
Lu, Z.
Powiązania:
https://bibliotekanauki.pl/articles/1969.pdf
Data publikacji:
2019
Wydawca:
Instytut Ogrodnictwa
Tematy:
paclobutrazol
plant growth regulator
photosynthetic activity
Sequoia sempervirens
seedling
morphological index
chlorophyll fluorescence
environmental stress
Źródło:
Journal of Horticultural Research; 2019, 27, 1
2300-5009
Pojawia się w:
Journal of Horticultural Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Proteomics profiles reveal the potential roles of proteins involved in chicken macrophages stimulated by Lipopolysaccharide
Autorzy:
Li, S.
Chen, Y.
Xue, W.
Wang, Q.
Huai, Z.
An, C.
Wang, Y.
Powiązania:
https://bibliotekanauki.pl/articles/16647586.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
chicken macrophage (HD11)
immune response
lipopolysaccharide (LPS)
proteomics
Opis:
Lipopolysaccharide (LPS), a core part of gram-negative bacteria, is crucial for inducing an inflammatory response in living things. In the current study, we used LPS from Salmonella to stimulate chicken macrophages (HD11). Proteomics was used to investigate immune-related proteins and their roles further. Proteomics investigation revealed 31 differential expression proteins (DEPs) after 4 hours of LPS infection. 24 DEPs expressions were up-regulated, while seven were down-regulated. In this investigation, ten DEPs were mainly enriched in S. aureus infection, complement, and coagulation cascades, which were all implicated in the inflammatory response and clearance of foreign pathogens. Notably, complement C3 was shown to be up-regulated in all immune-related pathways, indicating that it is a potential protein in this study. This work contributes to a better understanding and clarification of the processes of Salmonella infection in chickens. It might bring up new possibilities for treating and breeding Salmonella-infected chickens.
Źródło:
Polish Journal of Veterinary Sciences; 2023, 26, 2; 265-274
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Symulacja MES i optymalizacja prędkości gięcia w procesie kucia ciężkich, jednolitych wałów korbowych z ciągłym przebiegiem włókien metodą N-TR
FE simulation and bending speed optimization of N-TR continuous grain flow forging process for solid heavy crankshaft
Autorzy:
Zhang, L. H.
Zhang, Z. C.
Li, S. Y.
Cui, H.
Cui, H. X.
Powiązania:
https://bibliotekanauki.pl/articles/211742.pdf
Data publikacji:
2006
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Obróbki Plastycznej
Tematy:
ciężkie wały korbowe
kucie z ciągłym przebiegiem włókien
spęczanie
N-TR
symulacja MES
optymalizacja procesu
heavy crankshaft
continuous grain flow forging
upset forging
FE simulation
process optimization
Opis:
Autorzy przedstawili metodę N-TR (nowa TR) będącą nowym procesem kucia ciężkich, jednolitych wałów korbowych z ciągłym przebiegiem włókien. W metodzie N-TR mechaniczne sprzężenie spęczania z równoczesnym wyginaniem, spowodowane działaniem mechanizmu kolanowego w metodzie TR, zostało zlikwidowane dzięki zastosowaniu siłownika powodującego niezależne wyginanie, co umożliwia optymalizację procesu kucia. Przeprowadzono optymalizację procesu kucia ciężkiego wału korbowego typu 601 metodą N-TR korzystając z symulacji MES w programie DEFORM-3D. Badano związek stopnia wypełnienia wykrojów narzędzi z prędkością wyginania. Stwierdzono, że niższa prędkość wyginania na początku procesu i wyższa prędkość wyginania na końcu procesu sprzyjają wypełnieniu wykrojów. Uzyskano optymalne wypełnienie wykrojów narzędzi dla technicznie realnych prędkości wyginania.
N-TR (new TR) is a new continuous grain flow forging process for solid heavy crankshafts forming proposed by the authors. In N-TR process, the mechanical coupling of upsetting and bending action via the toggle mechanism in TR process is decoupled by an independent additional cylinder to provide bending action, which provides the feasibility of process optimization. In this paper, a heavy crankshaft modeled 601 was selected as a case study to optimize the N-TR process with FE simulation in DEFORM-3D. Relationship of die filling versus bending speed-stroke parameters was set up from the simulations, which shows that lower bending speed in the beginning stage and higher speed in the ending stage benefit die filling. Optimum die filling and engineering feasible speed-stroke parameters was acquired.
Źródło:
Obróbka Plastyczna Metali; 2006, 17, 2; 3-13
0867-2628
Pojawia się w:
Obróbka Plastyczna Metali
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ubiquitiformal fracture energy
Autorzy:
Ou, Z.-C.
Yang, M.
Li, G.-Y.
Duan, Z.-P.
Huang, F-L.
Powiązania:
https://bibliotekanauki.pl/articles/280189.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
fractal
ubiquitiform
fracture energy
size effect
Opis:
The ubiquitiformal fracture energy is proposed in the paper and its explicit expression is obtained. Moreover, the numerical results for concrete are found to be in good agreement with those for the critical strain energy release rate. The discrepancy between the numerical results of the traditional fracture energy and the critical strain energy release rate can be explained reasonably, which implies that the ubiquitiformal fracture energy should be taken as an available fracture parameter of materials. Finally, it is numerically found for some concrete that there is not size effect for the ubiquitiformal fracture energy.
Źródło:
Journal of Theoretical and Applied Mechanics; 2017, 55, 3; 1101-1108
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Weighted prediction method with multiple time series using multi-kernel least squares support vector regression
Metoda ważonej predykcji wielokrotnych szeregów czasowych z wykorzystaniem wielojądrowej regresji wektorów wspierających metodą najmniejszych kwadratów (LS-SVR)
Autorzy:
Guo, Y. M.
Ran, C. B.
Li, X. L.
Ma, J. Z.
Zhang, L.
Powiązania:
https://bibliotekanauki.pl/articles/302067.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
szereg czasowy
predykcja ważona
regresja wektorów wspierających metodą najmniejszych kwadratów (LS-SVR)
uczenie wielojądrowe (MKL)
time series
weighted prediction
least squares support vector regression (LS-SVR)
multiple kernel learning (MKL)
Opis:
Least squares support vector regression (LS-SVR) has been widely applied in time series prediction. Based on the case that one fault mode may be represented by multiple relevant time series, we utilize multiple time series to enrich the prediction information hiding in time series data, and use multi-kernel to fully map the information into high dimensional feature space, then a weighted time series prediction method with multi-kernel LS-SVR is proposed to attain better prediction performance in this paper. The main contributions of this method include three parts. Firstly, a simple approach is proposed to determine the combining weights of multiple basis kernels; Secondly, the internal correlative levels of multiple relevant time series are computed to present the different contributions of prediction results; Thirdly, we propose a new weight function to describe each data's different effect on the prediction accuracy. The experiment results indicate the effectiveness of the proposed method in both better prediction accuracy and less computation time. It maybe has more application value.
Regresja wektorów wspierających metodą najmniejszych kwadratów (LS-SVR) jest szeroko stosowana w predykcji szeregów czasowych. Opierając się na fakcie, że jeden rodzaj niezdatności może być reprezentowany przez wiele relewantnych szeregów czasowych, w niniejszej pracy wykorzystano wielokrotne szeregi czasowe do wzbogacenia informacji predykcyjnych ukrytych w szeregach czasowych oraz posłużono się metodą uczenia wielojądrowego (multi-kernel) w celu mapowania informacji do wysoko wymiarowej przestrzeni cech, a następnie zaproponowano metodę ważonej predykcji wielokrotnych szeregów czasowych z wykorzystaniem wielojądrowej regresji LS-SVR służącą osiągnięciu lepszej wydajności prognozowania.Metoda składa się z trzech głównych części. Po pierwsze, zaproponowano prosty sposób określania łącznej wagi wielu jąder podstawowych. Po drugie, obliczono wewnętrzne poziomy korelacyjne wielokrotnych szeregów czasowych w celu przedstawienia różnego udziału wyników prognozowania. Po trzecie, zaproponowano nową funkcję wagi do opisu różnego wpływu poszczególnych danych na trafność predykcji. Wyniki doświadczenia wskazują na skuteczność proponowanej metody zarówno jeśli chodzi o lepszą trafność predykcji jak i krótszy czas obliczeniowy. Proponowane rozwiązanie ma potencjalnie dużą wartość aplikacyjną.
Źródło:
Eksploatacja i Niezawodność; 2013, 15, 2; 188-194
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
System reliability modeling and assessment for solar array drive assembly based on bayesian networks
Modelowanie i ocena niezawodności systemu w oparciu o sieci bayesowskie na przykładzie układu napędu paneli słonecznych
Autorzy:
Li, Y. F.
Mi, J.
Huang, H. Z.
Xiao, N. C.
Zhu, S. P.
Powiązania:
https://bibliotekanauki.pl/articles/302154.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
drzewo uszkodzeń
dynamiczne drzewo uszkodzeń
sieć bayesowska
niezawodność systemu
układ napędu paneli słonecznych
fault tree
dynamic fault tree
Bayesian network
system reliability
solar array drive assembly
Opis:
Along with the increase of complexity in engineering systems, there exist many dynamic characteristics within the system failure process, such as sequence dependency, functional dependency and spares. Markov-based dynamic fault trees can figure out the modeling of systems with these characteristics. However, when confronted with the issue of state space explosion resulted from the growth of system complexity, the Markov-based approach is no longer efficient. In this paper, we combine the Bayesian networks with the dynamic fault trees to model the reliability of such types of systems. The inference technique of Bayesian network is utilized for reliability assessment and fault probability estimation. The solar array drive assembly is used to demonstrate the effectiveness of this method.
Wraz ze wzrostem złożoności w systemach technicznych, pojawia się wiele charakterystyk dynamicznych w ramach procesu awarii systemu, takich jak zależność sekwencyjna, zależność funkcjonalna czy zabezpieczające elementy zapasowe. Oparte na koncepcjach Markowa dynamiczne drzewa uszkodzeń mogą posłużyć do modelowania systemów z powyższymi charakterystykami. Jednak w konfrontacji z problemem eksplozji stanów wynikającym ze wzrostu złożoności systemu, podejście oparte na teoriach Markowa nie jest już skuteczne. W niniejszej pracy łączymy sieci bayesowskie z dynamicznymi drzewami uszkodzeń w celu modelowania niezawodności tego typu systemów. Technikę wnioskowania sieci bayesowskiej wykorzystano do oceny niezawodności i prawdopodobieństwa wystąpienia uszkodzenia. Skuteczność niniejszej metody wykazano na przykładzie układu napędu paneli słonecznych.
Źródło:
Eksploatacja i Niezawodność; 2013, 15, 2; 117-122
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł

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