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Tytuł:
Experimental study on the effect of micro-cracks on Brazilian tensile strength
Eksperymentalne badanie wpływu mikrospękań na wyniki badań wytrzymałości na rozciąganie według metody brazylijskiej
Autorzy:
Wang, X.
Powiązania:
https://bibliotekanauki.pl/articles/219114.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Brazilian split test
dry and water saturation
bedding fissure
strength coefficient
coal mine ground control
badania na rozciąganie metodą brazylijską
próbki suche i nasycone wodą
płaszczyzny spękań
współczynnik wytrzymałości
ochrona powierzchni w kopalniach węgla
Opis:
For coal mine ground control issues, it is necessary to propose a failure criteria accounting for the transversely isotropic behaviors of rocks. Hence, it is very helpful to provide experimental data for the validation of the failure criteria. In this paper, the method for preparing transversely isotropic specimens and the scheme of the Brazilian tensile strength test are presented. Results obtained from Brazilian split tests under dry and water-saturated conditions reflect the effect of the development direction β of the structural plane, such as the bedding fissure, on the tensile strength, ultimate displacement, failure mode, and the whole splitting process. The results show that the tensile strength decreases linearly with increasing β. The softening coefficient of the tensile strength shows a sinusoidal function. The values of the slope and inflection point for the curve vary at the different stages of the Brazilian test. The failure mode of the rock specimen presented in this paper generally coincides with the standard Brazilian splitting failure mode. Based on the test results, the major influencing factors for the Brazilian splitting strength are analyzed and a mathematical model for solving the Brazilian splitting strength is proposed. The findings in this paper would greatly benefit the coal mine ground control studies when the surrounding rocks of interest show severe transversely isotropic behaviors.
W związku z zagadnieniami ochrony powierzchni w kopalniach węgla, konieczne jest opracowanie odpowiednich kryteriów klasyfikacji uszkodzeń skał uwzględniających ich poprzeczną izotropowość. Pomocnym jest także dostarczenie danych eksperymentalnych niezbędnych do walidacji kryteriów uszkodzeń. W pracy tej zaproponowano metodę przygotowywania próbek wykazujących izotropowość poprzeczną, omówiono także sposób przeprowadzania testu na rozciąganie metodą brazylijską. Wyniki testu uzyskane na sucho oraz w warunkach nasycenia próbki wodą wskazują wpływ kierunku rozwoju β płaszczyzny strukturalnej (np. płaszczyzn spękań) na wytrzymałość próbki na rozciąganie, maksymalne przemieszczenia, rodzaj uszkodzenia oraz przebieg procesu pękania. Wyniki testu wskazują, że wytrzymałość na rozciąganie maleje liniowo wraz ze wzrostem wartości β. Współczynnik mięknienia próbki w trakcie próby wytrzymałościowej na rozciąganie ma przebieg krzywej sinusoidalnej. Wartości kąta nachylenia oraz punkt przegięcia krzywej różnią się dla poszczególnych etapów próby wytrzymałościowej. Tryb uszkodzeń próbek skalnych przedstawiony w artykule zasadniczo pozostaje w zgodzie z typowymi odkształceniami rejestrowanymi w trakcie testu metodą brazylijską. W oparciu o wyniki eksperymentu, przeanalizowano główne czynniki wpływające na wytrzymałość próbek na rozciąganie i zaproponowano odpowiedni model matematyczny do obliczania wytrzymałości. Wyniki przedstawione w artykule stanowią poważny przyczynek do badań stabilności gruntu i ochrony powierzchni w rejonach górniczych w przypadku gdy sąsiadujące z kopalnią skały wykazują izotropowość poprzeczną.
Źródło:
Archives of Mining Sciences; 2015, 60, 4; 985-996
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improved dolphin swarm optimization algorithm based on information entropy
Autorzy:
Li, Y.
Wang, X.
Powiązania:
https://bibliotekanauki.pl/articles/200085.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
dolphin swarm optimization
information entropy
convergence
self-adaptive
combinational optimization
Opis:
In order to overcome the shortcomings of the dolphin algorithm, which is prone to falling into local optimum and premature conver-gence, an improved dolphin swarm algorithm, based on the standard dolphin algorithm, was proposed. As a measure of uncertainty, information entropy was used to measure the search stage in the dolphin swarm algorithm. Adaptive step size parameters and dynamic balance factors were introduced to correlate the search step size with the number of iterations and fitness, and to perform adaptive adjustment of the algorithm. Simulation experiments show that, comparing with the basic algorithm and other algorithms, the improved dolphin swarm algorithm is feasible and effective.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2019, 67, 4; 679-685
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A screw dislocation located outside, inside or on the interface of a parabolic elastic inhomogeneity
Autorzy:
Wang, X.
Schiavone, P.
Powiązania:
https://bibliotekanauki.pl/articles/38627364.pdf
Data publikacji:
2021
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
screw dislocation
parabolic elastic inhomogeneity
superposition
conformal mapping
analytic continuation
Opis:
Using conformal mapping techniques, superposition and analytic continuation, we derive analytic solutions to the problem of a screw dislocation interacting with a parabolic elastic inhomogeneity. The screw dislocation can be located anywhere either in the surrounding matrix or in the parabolic inhomogeneity or simply on the parabolic interface itself. We obtain explicit expressions for the two analytic functions in the image plane characterizing the elastic fields describing displacement and stresses in the two-phase composite. Using the Peach-Koehler formula, we also obtain the image force acting on the screw dislocation. The analytic function defined in the parabolic inhomogeneity in the physical plane can be interpreted in terms of real and image screw dislocations for any location of the real screw dislocation.
Źródło:
Archives of Mechanics; 2021, 73, 3; 219-235
0373-2029
Pojawia się w:
Archives of Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Uniformity of electroelastic field within a three-phase anisotropic piezoelectric elliptical inhomogeneity in anti-plane shear
Autorzy:
Wang, X.
Schiavone, P.
Powiązania:
https://bibliotekanauki.pl/articles/38694715.pdf
Data publikacji:
2022
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
three-phase elliptical inhomogeneity
confocal ellipses
monoclinic piezoelectric material
transversely isotropic piezoelectric material
Stroh quartic formalism
real-form solution
Opis:
Using the Stroh quartic formalism, we prove that the internal electroelastic field is unconditionally uniform inside a three-phase anisotropic piezoelectric elliptical inhomogeneity with two confocal elliptical interfaces when the surrounding matrix is subjected to uniform remote anti-plane mechanical and in-plane electrical loading. The inhomogeneity and the matrix comprise monoclinic piezoelectric materials with symmetry plane at x3 = 0 and with poling in the x3-direction; the intermediate interphase layer is a transversely isotropic piezoelectric material with poling in the x3-direction. Moreover, we obtain the internal uniform electroelastic field inside the elliptical inhomogeneity and the non-uniform electroelastic field in the interphase layer in real-form in terms of the fundamental piezoelectricity matrices for both the inhomogeneity and the matrix and the generalized Barnett–Lothe tensors for both the interphase layer and the matrix.
Źródło:
Archives of Mechanics; 2022, 74, 2-3; 143-156
0373-2029
Pojawia się w:
Archives of Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
SO(3) matrix transformation for rapid polarization search and coding in a three-plate polarizer
Autorzy:
Huang, C
Wang, X
Powiązania:
https://bibliotekanauki.pl/articles/174349.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
SO(3) transformer
tabu search
polarization coding
Opis:
A SO(3) transformer of a three-plate polarizer is adopted to rapidly achieve the transformation of the polarized state. The polarization coding based on Stokes components S2 and S3 is analyzed and demonstrated. Tabu search algorithm is used to accelerate the transformation of the polarized state by utilizing Mueller matrix roots decomposition to decompose the SO(3) matrix, and substituting first order Taylor series approximations for the trigonometric functions in the SO(3) matrix. The results show that bias voltage is less than 120 V in the coding zone. The search speed of our algorithm is faster than the one without first order Taylor series approximations by 4 times.
Źródło:
Optica Applicata; 2015, 45, 1; 101-112
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
NH4+ adsorption and adsorption kinetics by sediments in a drinking water reservoir
Autorzy:
Sun, H.
Wang, X.
Powiązania:
https://bibliotekanauki.pl/articles/204766.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
reservoir
sediment
sorption
sorption isotherm
sorption kinetics
Opis:
The sorption isotherm and sorption kinetics of NH4+by the Fen River reservoir sediment were investigated for a better understanding of the NH4+ sorption characteristics and parameters. The results showed that Q (adsorption content) increased with the increase of Ceq (equilibrium concentration), sorption isotherms could be described by Freundlich equation (R2 from 0.97 to 0.99). Cation exchange capacity (CEC) had a significant correlation with the parameters K and n (R2 was 0.85 and 0.95, respectively). The ENC0 (Ceq as Q was zero) of S1, S2, S3 and S4 was 1.25, 0.57, 1.15 and 1.14 mg L-1, respectively, and they were less than the NH4+ concentrations in reservoir water. The sediments released NH4+ to the Fen River reservoir water and acted as a pollution source, in the form of complex and heterogeneous adsorbents. The NH4+ adsorption kinetic process was composed of ‘fast’ and ‘slow’ reaction patterns and could be fitted using both Elovich equation and Pseudo second-equation. More than one-step may be involved in the NH4+ sorption processes, and interior diffusion was not dominant ion action.
Źródło:
Archives of Environmental Protection; 2016, 42, 4; 90-95
2083-4772
2083-4810
Pojawia się w:
Archives of Environmental Protection
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A mode-III crack with variable surface effects
Autorzy:
Wang, X.
Schiavone, P.
Powiązania:
https://bibliotekanauki.pl/articles/282009.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
surface elasticity
variable surface moduli
mode-III crack
Cauchy singular integro-differential equation
Opis:
We study the contribution of variable surface effects to the antiplane deformation of a linearly elastic material with a mode-III crack. The surface elasticity is incorporated using a modified version of the continuum based surface/interface model of Gurtin and Murdoch. In our discussion, the surface moduli are not constant but vary along the crack surfaces. Using Green’s function method, the problem is reduced to a single first-order Cauchy singular integro-differential equation, which is solved numerically using Chebyshev polynomials and a collocation method. Our results indicate that the gradient of the surface shear modulus exerts a significant influence on the crack opening displacement and on the singular stress field at the crack tips.
Źródło:
Journal of Theoretical and Applied Mechanics; 2016, 54, 4; 1319-1327
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Three-phase parabolic inhomogeneities with internal uniform stresses in plane and anti-plane elasticity
Autorzy:
Wang, X.
Schiavone, P.
Powiązania:
https://bibliotekanauki.pl/articles/38442156.pdf
Data publikacji:
2020
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
three-phase parabolic inhomogeneity
coating
internal uniform stresses
plane elasticity
anti-plane elasticity
Opis:
We examine the in-plane and anti-plane stress states inside a parabolic inhomogeneity which is bonded to an infinite matrix through an intermediate coating. The interfaces of the three-phase parabolic inhomogeneity are two confocal parabolas. The corresponding boundary value problems are studied in the physical plane rather than in the image plane. A simple condition is found that ensures that the internal stress state inside the parabolic inhomogeneity is uniform and hydrostatic. Furthermore, this condition is independent of the elastic properties of the coating and the two geometric parameters of the composite: in fact, the condition depends only on the elastic constants of the inhomogeneity and the matrix and the ratio between the two remote principal stresses. Once this condition is met, the mean stress in the coating is constant and the hoop stress on the coating side is also uniform along the entire inhomogeneity-coating interface. The unconditional uniformity of stresses inside a three-phase parabolic inhomogeneity is achieved when the matrix is subjected to uniform remote anti-plane shear stresses. The internal uniform anti-plane shear stresses inside the inhomogeneity are independent of the shear modulus of the coating and the two geometric parameters of the composite.
Źródło:
Archives of Mechanics; 2020, 72, 1; 27-38
0373-2029
Pojawia się w:
Archives of Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Uniform stress field inside a non-parabolic open inhomogeneity interacting with a mode III crack
Autorzy:
Wang, X.
Schiavone, P.
Powiązania:
https://bibliotekanauki.pl/articles/38612202.pdf
Data publikacji:
2021
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
non-parabolic inhomogeneity
mode III crack
uniform stress field
antiplane elasticity
conformal mapping
singular integral equation
Opis:
Using conformal mapping techniques, analytic continuation and the theory of Cauchy singular integral equations, we prove that a non-parabolic open inhomogeneity embedded in an elastic matrix subjected to a uniform remote anti-plane stress nevertheless admits an internal uniform stress field despite the presence of a finite mode III crack in its vicinity. Our analysis indicates that: (i) the internal uniform stress field is independent of the specific shape of the inhomogeneity and the presence of the finite crack; (ii) the existence of the finite crack plays a key role in the non-parabolic open shape of the inhomogeneity and in the non-uniform stresses in the surrounding matrix; (iii) the two-term asymptotic expansion at infinity of the stress field in the matrix is independent of the presence of the finite crack. Detailed numerical results are presented to demonstrate the proposed theory.
Źródło:
Archives of Mechanics; 2021, 73, 1; 67-81
0373-2029
Pojawia się w:
Archives of Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Uniform field within a non-elliptical inhomogeneity in the vicinity of a nearby non-circular Eshelby inclusion
Autorzy:
Wang, X.
Schiavone, P.
Powiązania:
https://bibliotekanauki.pl/articles/38629511.pdf
Data publikacji:
2021
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
non-elliptical inhomogeneity
Booth’s lemniscate inclusion
uniform field
conformal mapping
anti-plane elasticity
inverse problem
Opis:
We rigorously prove that a non-elliptical inhomogeneity continues to permit an internal uniform stress field despite the presence of a nearby non-circular Eshelby inclusion undergoing uniform anti-plane eigenstrains when the surrounding matrix is subjected to uniform remote anti-plane stresses. Here, we adopt a specific representation of the non-circular Eshelby inclusion as a Booth’s lemniscate inclusion. Our analysis indicates that the internal uniform stress field inside the non-elliptical inhomogeneity is independent of the existence of the Booth’s lemniscate inclusion whereas the non-elliptical shape of the inhomogeneity is attributed entirely to its presence. Representative numerical examples are presented to demonstrate the feasibility of the proposed method of general solution.
Źródło:
Archives of Mechanics; 2021, 73, 5-6; 541-555
0373-2029
Pojawia się w:
Archives of Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Positive solutions for the one-dimensional p-Laplacian with nonlinear boundary conditions
Autorzy:
Hai, D. D.
Wang, X.
Powiązania:
https://bibliotekanauki.pl/articles/255386.pdf
Data publikacji:
2019
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
p-Laplacian
semipositone
nonlinear boundary conditions positive solutions
Opis:
We prove the existence of positive solutions for the p-Laplacian problem [formula] where [formula] can be nonlinear, i=1,2 , f:(0,∞)→R is p-superlinear or p-sublinear at ∞ and is allowed be singular (±∞) at 0, and λ is a positive parameter.
Źródło:
Opuscula Mathematica; 2019, 39, 5; 675-689
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dodecyl amine adsorption at different interfaces during bubble attachment/detachment at a silica surface
Autorzy:
Wang, X.
Miller, J. D.
Powiązania:
https://bibliotekanauki.pl/articles/110684.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
VSFS
air bubble attachment
amine adsorption density
Opis:
The reverse flotation of quartz and other gangue silicate minerals with alkyl amines is an important and well known strategy for the processing of iron ore, low grade bauxite ore, and phosphate rock. Some details of amine adsorption by quartz have been described in the literature, but little is known about the disposition of amine during bubble attachment. Now, a new experimental procedure involving vibrational sum frequency spectroscopy (VSFS) has been developed to provide, for the first time, a more detailed analysis of the state of dodecyl amine (DDA) adsorption at different interfaces during bubble attachment/detachment at a silica surface. The results show that the hydrophobic surface state at the silica surface is created by the transfer of a well-organized monolayer of DDA from the bubble surface to the silica surface during bubble contact and attachment.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 1; 81-88
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of Temperature Field, Heat and Fluid Flow of Two-Phase Zone Continuous Casting Cu–Sn Alloy Wire
Autorzy:
Luo, J.
Liu, X.
Wang, X.
Powiązania:
https://bibliotekanauki.pl/articles/380230.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
continuous casting
two-phase zone continuous casting
alloy Cu-Sn
numerical simulation
temperature field
heat flow
fluid flow
odlewanie ciągłe
strefa odlewania dwufazowego
stop Cu-Sn
symulacja numeryczna
pole temperatury
przepływ ciepła
przepływ płynu
Opis:
Cu–4.7 wt. % Sn alloy wire with Ø10 mm was prepared by two-phase zone continuous casting technology, and the temperature field, heat and fluid flow were investigated by the numerical simulated method. As the melting temperature, mold temperature, continuous casting speed and cooling water temperature is 1200°C, 1040°C, 20 mm/min and 18°C, respectively, the alloy temperature in the mold is in the range of 720°C–1081°C, and the solid/liquid interface is in the mold. In the center of the mold, the heat flow direction is vertically downward. At the upper wall of the mold, the heat flow direction is obliquely downward and deflects toward the mold, and at the lower wall of the mold, the heat flow deflects toward the alloy. There is a complex circular flow in the mold. Liquid alloy flows downward along the wall of the mold and flows upward in the center.
Źródło:
Archives of Foundry Engineering; 2016, 16, 1; 33-40
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Climatic response of Betula ermanii along an altitudinal gradient in the northern slope of Changbai Mountain, China
Autorzy:
Wang, X.
Zhao, X.
Gao, L.
Powiązania:
https://bibliotekanauki.pl/articles/41735.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Opis:
The sensitivity of Betula ermanii tree-ring growth to climate variation over an altitudinal gradient was assessed. Betula ermanii forest grows in the northern slope of Changbai Mountain from approximately 1,700mabove sea level (a.s.l.), andforms the upper tree line at nearly 2,100ma.s.l.. Six study sites were constructed along the altitudinal gradient (1,670 to 2,010 m a.s.l.) and ring-width chronologies of Betula ermanii were built. The mean tree-ring series intercorrelation (RBAR) increasedwith elevation. In principal component analysis, the first unrotatedprinciple component explained77.1% of the total variance, indicating the tree-ring growth of Beutla ermanii over the altitudinal gradient was governed by regional climate. Correlation function analysis revealedthat the radial growth of Betula ermanii was significantly similar in response to climatic conditions. Overall, the low temperatures during previous June, July and during the dormant period (previous October to current May) andthe high temperatures during current June, July andAugust would benefit the radial growth of Betula ermanii. Abundant precipitation during growing season (previous June, July, September andcurrent August), previous November andcurrent May, wouldalso facilitate the tree-ring growth. The reason for this uniform growth behavior in Betula ermanii remainedunclear. Betula ermanii in Changbai Mountain formedrelatively pure stands with an open canopy, which might be partly contributing to the common growth response to climatic signals along the altitudinal gradient, but further work was required for testing this assumption.
Źródło:
Dendrobiology; 2013, 70
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Machine Learning Method of PIDVCA
Autorzy:
Li, L.
Wang, X.
Chen, G.
Powiązania:
https://bibliotekanauki.pl/articles/1841618.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
learning methods
personified intelligence
collision avoidance
dynamic collision avoidance
static collision avoidance
Opis:
Building a dynamic collision knowledge base of self-learning is one of the core contents of implementing "personified intelligence" in Personifying Intelligent Decision-making for Vessel Collision Avoidance (short for PIDVCA). In the paper, the machine learning method of PIDVCA combined with offline artificial learning and online machine learning is proposed. The static collision avoidance knowledge is acquired through offline artificial learning, and the isomeric knowledge representation integration method with process knowledge as the carrier is established, and the Dynamic collision avoidance knowledge is acquired through online machine learning guided by inference engine. A large number of simulation results show that the dynamic collision avoidance knowledge base constructed by machine learning can achieve the effect of anthropomorphic intelligent collision avoidance. It is verified by examples that the machine learning method of PIDVCA can realize target perception, target cognition and finally obtain an effective collision avoidance decision-making.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2020, 14, 3; 533-540
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stimulate economic growth by improving transport infrastructure – a lesson from China
Stimuliertes wirtschaftliches Wachstum durch verbesserung der Transportinfrastrukutr - ein lektor aus China
Autorzy:
Wang, X.
Deng, D.
Wu, X.
Powiązania:
https://bibliotekanauki.pl/articles/374982.pdf
Data publikacji:
2014
Wydawca:
Politechnika Śląska. Wydawnictwo Politechniki Śląskiej
Tematy:
transport infrastructure
economic growth
spillover effects
infrastruktura transportu
wzrost gospodarczy
efekty zewnętrzne
Opis:
This paper uses Feder model to test impacts of transport infrastructure on economic growth. With China provincial data from 1990-2010 the empirical models, including Basic model, Time-Lag model and Spatial model, demonstrate that transport infrastructure does have a positive Spillover Effect on economic growth. However, Direct Effect on economic growth is negative possibly due to Crowding-Out Effect and productivity difference between sectors. The research also proves the Spillover Effects are becoming weaker as time passed. Finally, Spatial Spillover Effect or Network Effects are confirmed.
Diese Thesis benutzt Feder-Model, um die Auswirkung der Transportinfrastruktur, die auf das wirtschaftliche Wachstum zu untersuchen. Mit den Daten aus chinesischen Provinzen zwischen 1990 und 2010 durch das empirische Modell, in dem das Basic-Model, Time-Lag-Model und Spatial-Model beinhaltet, kann man dadurch demonstrieren, dass die Transportinfrastruktur eine positive Spillover-Effekt auf das wirtschaftliche Wachstum auswirkt. Direkte Effekt auf das wirtschaftliche Wachstum ist jedoch möglich negativ, durch die Crowding-Out Effekt und Unausgeglichenheit der Produktivität zwischen Sektoren. Diese Studie beweist auch, dass die Spillover-Effekte mit vergangener Zeit schwächt wird. Außerdem werden die Spatial-Spillover-Effekt oder Network-Effekt nachgewiesen.
Źródło:
Transport Problems; 2014, 9, 4; 63-72
1896-0596
2300-861X
Pojawia się w:
Transport Problems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental study of a small gas-puff Z-pinch device
Autorzy:
Luo, C.
Wang, X.
Zou, X.
Powiązania:
https://bibliotekanauki.pl/articles/147416.pdf
Data publikacji:
2006
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
Z-pinch plasma
plasma diagnostics
multi-frame interferometry
electron density
energy spectra of ion beams
Opis:
A small gas puff Z-pinch device has been constructed and operated. The device has the parameters: the capacitance of energy storage capacitors 16 mi F, charging voltage 22 kV, peak current 210 kA and a quarter of current period 2.4 mi s. A three-frame Mach-Zehnder interferometer and a compact Thomson ion energy analyzer were developed for Z-pinch plasma experiment. According to the results of diagnostics, the electron density ne of the plasma right before pinch instant is larger than 5.4 × 1019/cm3, the corresponding pinch velocity v of the plasma sheath is 9.0 cm/ěs. Clear parabolas produced by neon ions Ne+, Ne2+, Ne3+ and Ne4+ on CR-39 target have been observed. The energy spectra dN/dTdů for Ne+, Ne2+, Ne3+ and Ne4+ ions were determined. The highest energies of Ne+, Ne2+, Ne3+ and Ne4+ ions emitted from our Z-pinch plasma are below 1.3 MeV.
Źródło:
Nukleonika; 2006, 51, 1; 43-46
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Degradation mechanism study of amine collectors in Fenton process by quantitative structure-activity relationship analysis
Autorzy:
Wang, X.
Liu, W.
Duan, H.
Powiązania:
https://bibliotekanauki.pl/articles/110363.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
amine collectors
Fenton process
QSAR
degradation mechanism
quantum chemistry
Opis:
In this study, advanced oxidation processes (AOPs), Fenton process, was applied to degrade ten amine collectors. The experimental results indicated that most of the tested amines could be removed rapidly and effectively at pH=4, while the degradation of quaternary ammonium compounds was less than others. To research the Fenton oxidation process, the degradation-rate constants of amine collectors were calculated by the pseudo-second order kinetic model, then which was used as the dependent variable to establish a quantitative structure activity relationship (QSAR) model. Meanwhile, 16 molecular structure descriptors and quantum mechanical parameters for amine collectors were simulated and analyzed by using Materials Studio software. The optimum QSAR model was established based on the partial least squares regression (PLS) method and confirmed by the statistics analysis. The model revealed that hydrogen bond acceptor (HBA) and the maximum values of electrophilic attack in C atom sites (f(-)c) were the major effect factors for the degradation-rate constants of amine collector.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 3; 713-721
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effect of high ship speed ratio on collision avoidance behavior of COLREGS
Autorzy:
Wang, X. H.
Li, L.
Chen, G.
Powiązania:
https://bibliotekanauki.pl/articles/116490.pdf
Data publikacji:
2019
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
colregs
Personifying Intelligent Decision-making for Vessel Collision Avoidance (PIDVCA)
Vessel Collision Avoidance
collision avoidance
decision making
relative motion
geometricdiagram of relative motion
anti-collision
Opis:
The speed ratio is an important factor that must be considered when two vessels will course change to avoid collision. In the process of the research on Personifying Intelligent Decision-making for Vessel Collision Avoidance (short for PIDVCA), it is found that the effect of collision avoidance based on the existing “International Regulations for Prevention Collision at sea” (short for COLREGS) is greatly affected by the high speed ratio (k=Vt/V0≥1.5). Through the analysis on the geometric change law of two vessels’ relative motion in Open waters, the effects of the responsibility for the ship collision avoidance under the COLREGS and special case for high-speed ratio is discussed. According to the collision avoidance measures taken for two vessels encounter situation, some reasonable suggestions are put forward and the simulation experiments that based on ship's intelligent collision avoidance simulation platform are given to support the idea.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2019, 13, 2; 319-323
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Automated approach to classification of mine-like objects using multiple-aspect sonar images
Autorzy:
Wang, X.
Liu, X.
Japkowicz, N.
Matwin, S.
Powiązania:
https://bibliotekanauki.pl/articles/91790.pdf
Data publikacji:
2014
Wydawca:
Społeczna Akademia Nauk w Łodzi. Polskie Towarzystwo Sieci Neuronowych
Tematy:
object
sea bed
multiple side-scan sonar
Dempster-Shafer theory
DS concept
classifier
imbalance
imbalanced problem
multi-instance class
Opis:
In this paper, the detection of mines or other objects on the seabed from multiple side-scan sonar views is considered. Two frameworks are provided for this kind of classification. The first framework is based upon the Dempster–Shafer (DS) concept of fusion from a single-view kernel-based classifier and the second framework is based upon the concepts of multi-instance classifiers. Moreover, we consider the class imbalance problem which is always presents in sonar image recognition. Our experimental results show that both of the presented frameworks can be used in mine-like object classification and the presented methods for multi-instance class imbalanced problem are also effective in such classification.
Źródło:
Journal of Artificial Intelligence and Soft Computing Research; 2014, 4, 2; 133-148
2083-2567
2449-6499
Pojawia się w:
Journal of Artificial Intelligence and Soft Computing Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of processing parameters on the properties of amphiphilic block copolymer micelles prepared by supercritical carbon dioxide evaporation method
Autorzy:
Jiao, Z.
Wang, Z.
Wang, X.
Fan, W.
Powiązania:
https://bibliotekanauki.pl/articles/778902.pdf
Data publikacji:
2018
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
supercritical carbon dioxide
amphiphilic block copolymer
drug-loaded micelles
processing parameters
optimization
Opis:
The operation parameters for the supercritical carbon dioxide (ScCO2 ) evaporation method greatly affect the properties of the prepared drug-loaded micelles. In this study, the effects of those key parameters on the drug-loading content (LC) and drug entrapment efficiency (EE) are discussed. It is observed that EE and LC of the micelles are slightly increased with the enhancing temperature and the copolymer molecular ratio of hydrophilic/hydrophobic segment, while decreased with the enhancing ScCO2  evaporation rate. The pressure and volume ratio of ScCO2  to H2 O are observed the optimum condition. In addition, the verification experiment is carried out under the obtained optimizing parameters. The prepared micelles exhibit relatively regular spherical shape and narrow size distribution with the EE and LC value of 70.7% and 14.1%, respectively.
Źródło:
Polish Journal of Chemical Technology; 2018, 20, 1; 81-86
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Speech emotion recognition based on sparse representation
Autorzy:
Yan, J.
Wang, X.
Gu, W.
Ma, L.
Powiązania:
https://bibliotekanauki.pl/articles/177778.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
speech emotion recognition
sparse partial least squares regression SPLSR
SPLSR
feature selection and dimensionality reduction
Opis:
Speech emotion recognition is deemed to be a meaningful and intractable issue among a number of do- mains comprising sentiment analysis, computer science, pedagogy, and so on. In this study, we investigate speech emotion recognition based on sparse partial least squares regression (SPLSR) approach in depth. We make use of the sparse partial least squares regression method to implement the feature selection and dimensionality reduction on the whole acquired speech emotion features. By the means of exploiting the SPLSR method, the component parts of those redundant and meaningless speech emotion features are lessened to zero while those serviceable and informative speech emotion features are maintained and selected to the following classification step. A number of tests on Berlin database reveal that the recogni- tion rate of the SPLSR method can reach up to 79.23% and is superior to other compared dimensionality reduction methods.
Źródło:
Archives of Acoustics; 2013, 38, 4; 465-470
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling of ship’s trajectory planning in collision situations by hybrid genetic algorithm
Autorzy:
Ni, S.
Liu, Z.
Cai, Y.
Wang, X.
Powiązania:
https://bibliotekanauki.pl/articles/259640.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
trajectory planning
Multiple Genetic Algorithm
ship collision avoidance
nonlinear programming
COLREGs
Opis:
Ship collision-avoidance trajectory planning aims at searching for a theoretical safe-critical trajectory in accordance with COLREGs and good seamanship. In this paper, a novel optimal trajectory planning based on hybrid genetic algorithm is presented for ship collision avoidance in the open sea. The proposed formulation is established based on the theory of the Multiple Genetic Algorithm (MPGA) and Nonlinear Programming, which not only overcomes the inherent deficiency of the Genetic Algorithm (GA) for premature convergence, but also guarantees the practicality and consistency of the optimal trajectory. Meanwhile, the encounter type as well as the obligation of collision avoidance is determined according to COLREGs, which is then considered as the restricted condition for the operation of population initialization. Finally, this trajectory planning model is evaluated with a set of test cases simulating various traffic scenarios to demonstrate the feasibility and superiority of the optimal trajectory.
Źródło:
Polish Maritime Research; 2018, 3; 14-25
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Peridynamic analysis of 2-dimensional deformation and fracture based on an improved technique of exerting traction on boundary surface
Autorzy:
Zhou, Z.
Yu, M.
Wang, X.
Huang, Z.
Powiązania:
https://bibliotekanauki.pl/articles/38695705.pdf
Data publikacji:
2022
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
peridynamics
peridynamic motion equation
adaptive dynamic relaxation
traction boundary conditions
Opis:
For 2-dimensional problems in peridynamics, the transfer functions of boundary traction are constructed. The peridynamic motion equation introducing the boundary traction is improved and used to solve some typical 2-dimensional deformation and fracture problems, including the uniaxial tension and pure bending of plate, and fracture of a plate with the small circular hole or central crack. The acquired numerical solutions are close to the analytical solutions of elasticity and numerical solutions given by the finite element method. The results show that the improved technique of exerting traction on a boundary surface is valid for calculating the deformation and failure of solid. It provides a new method and path for the analysis of traction boundary value problems in peridynamics.
Źródło:
Archives of Mechanics; 2022, 74, 6; 441-461
0373-2029
Pojawia się w:
Archives of Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Phase Transition and Plasticity Enhancement of Ti-Cu-Based Bulk Metallic Glasses
Autorzy:
Wang, L.
Wang, X.
Zhang, G.
Sun, X.
Powiązania:
https://bibliotekanauki.pl/articles/356824.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
bulk metallic glasses
phase transition
annealing
stability
plasticity
Opis:
In this paper, we report the complex crystallization kinetics of phase transition happening in Ti-Cu-based bulk metallic glasses (BMGs), which play significant roles in the glass formation with respect to their low reduced glass transition temperatures, Trg. The first exothermic event just occurs when annealing the BMG samples in the supercooled liquid region, leading to the Avrami exponent deviating from conventional modes affected by the residual amorphous phase. For Ti43Cu43Ni7Zr7 BMG, the plasticity can be improved by pre-annealing at a sub-Tg temperature of 623K (≈50K below Tg) for 0.5 hour, however, deteriorated by 1 hour annealing, which could be related to the change in stability of this BMG against crystallization with different pre-annealing times.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 1; 387-391
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Metal Fibre Content of Blended Electromagnetic Shielding Fabric on Shielding Effectiveness Considering Fabric Weave
Wpływ zawartości włókien metalowych w tkaninach z przędz mieszankowych tworzących barierę elektromagnetyczną na wydajność ekranowania w zależności od splotu tkaniny
Autorzy:
Liu, Z.
Zhang, Y.
Rong, X.
Wang, X.
Powiązania:
https://bibliotekanauki.pl/articles/233107.pdf
Data publikacji:
2015
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
fabric blended electromagnetic shielding
fabric structure
metal fibre content
shielding effectiveness
metal fibre influence
tkaniny barierowe
mieszankowe tkaniny ekranujące
struktura tkaniny
zawartość włókien metalowych
gęstość wątku i osnowy
masa liniowa przędzy
wpływ włókien metalowych
Opis:
There are few researches reported about the influence of the metal fibre content of blended electromagnetic shielding (EMS) fabric on shielding effectiveness (SE) under different fabric parameters. In order to scientifically describe the metal fibre content of blended EMS fabric considering the fabric structure, in this paper two new indicators of structure metal fibre content (SMFC) and structure equivalent thickness (SET) were constructed according to fabric structure parameters of weft and warp density, yarn density and yarn metal content. A number of experiments were designed and sixteen groups of samples prepared to explore the influence of the two indicators on the SE. Firstly the SMFC and SET of the samples were calculated by the equations of the new indicators. SE values of the samples were then tested by the waveguide method. Finally the relations between the new indicators and the SE were analysed according to experimental results and electromagnetic wave theory. Results show that the SMFC and SET can scientifically describe the metal fibre content of the blended EMS fabric. The SMFC and SET show positive growth along with the SE while other parameters remain unchanged. For the basic weave, SE values are an approximate equivalence as long as the total densities are the same as the yarn density and fibre content of the yarns is the same. As the SMFC is consistent, the more floats, the lower the SE. The research in this paper can provide an important reference for the design, testing and production of blended EMS fabric.
Niewiele publikacji opisuje wpływ zawartości włókien metalowych w mieszankowych tkaninach ekranujących przed wpływem promieniowania elektromagnetycznego na wydajność ekranowania w zależności od parametrów tkaniny. W celu naukowego opisu wpływu zawartości włókien metalowych na zdolność ekranowania w zależności od struktury tkaniny zaproponowano dwa nowe współczynniki SMFC (zależny od struktury) i SET (strukturalny ekwiwalent grubości). Współczynniki oblicza się uwzględniając parametry strukturalne m. in. takie jak gęstość wątku i osnowy, masę liniową przędzy i ilość włókien metalowych. Zaprojektowano serię eksperymentów i zaproponowano 16 grup próbek tak zaprojektowanych, aby można było zbadać wpływ parametrów na dwa nowo zaproponowane współczynniki. Wartości współczynników zostały obliczone, a zdolność ekranowania próbek pomierzona w specjalnym urządzeniu badawczym. Analiza wyników pokazała, że nowo zaproponowane współczynniki mogą charakteryzować wielkość tłumienia w zależności od zastosowanej ilości włókien metalowych. Stwierdzono wyraźne zależności tłumienia od stosowanych częstotliwości. Uzyskane wyniki mogą stanowić podstawę dla projektowania, sprawdzania i produkcji tkanin barierowych dla promieniowania elektromagnetycznego.
Źródło:
Fibres & Textiles in Eastern Europe; 2015, 4 (112); 83-87
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetohydrodynamic Calculation on Double-Loop Channel Induction Tundish
Autorzy:
Yue, Q.
Pei, X.
Zhang, C.
Wang, X.
Powiązania:
https://bibliotekanauki.pl/articles/350969.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
induction heating
electromagnetic field
channel
tundish
Opis:
A mathematical model is developed to investigate the electromagnetic induction heating in a continuous casting tundish with the double-loop inductor. Maxwell’s equations are solved using finite element method to obtain the magnetic flux density, electromagnetic force, and Joule heating. Results show that the induced current through the two channels generates a current loop. The electromagnetic force points to the center of the channel, thus generating a pinch effect on the molten steel. With the skin effect and proximity effect, Joule heating rate reaches its maximum and minimum values at the corners and the center of the crosssection area respectively. Power ampere-turn has a significant influence on the electromagnetic force and Joule heating density. As ampere-turns vary from 3.6×104 to 2.16×105, Joule heating rate increases from 2.4 MW m-3 to 85 MW m-3. Electromagnetic force also increases from 8×104 N m-3 to 3×106 N m-3 in the center axis line of the channel. The present work reveals the relationship between magnetic flux density and electromagnetic force. The results will be helpful in adjusting the electromagnetic field in channel-induction furnaces and modifying the design of channel parameters.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 1; 329-336
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A novel in-phase disposition SPWM pulse allocation strategy for cascaded H-bridge inverter
Autorzy:
Zhang, Y.
Xiong, J.
Kong, L.
Wang, X.
Powiązania:
https://bibliotekanauki.pl/articles/141155.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
in-phase disposition SPWM
Inverter
CHB
THD
Opis:
A novel in-phase disposition (IPD) SPWM pulse allocation strategy applied to a cascaded H-bridge (CHB) converter is presented in this paper. The reason causing the power of the CHB converter imbalance is analyzed according to the traditional structure, the conception of power imbalance degree is introduced and the principle of the novel in-phase disposition SPWM allocation strategy is deduced in detail. The new pulse allocation scheme can ensure the power balance in 3/4 cycles through interchanging the PWM pulse sequence of the different CHB cell, meanwhile it makes the full advantage of the IPD control strategy, lower the total harmonic distortion (THD) of line voltage compared to a carrier phase shifted (CPS) control strategy, which is verified by theoretical derivation. A seven-level cascaded inverter composed by three H-bridge cells is taken as the example. The simulation and experiment is performed. The results indicate the validity of the analysis and verify the effectiveness of the proposed SPWM allocation strategy.
Źródło:
Archives of Electrical Engineering; 2018, 67, 2; 361--375
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A polarization filter at 1550 nm based on photonic crystal fiber with symmetry around gold-coated holes
Autorzy:
Zha, F.
Li, J.
Sun, P.
Wang, X.
Powiązania:
https://bibliotekanauki.pl/articles/173897.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
photonic crystal fiber
polarization filter
finite element method
surface plasmon resonance
Opis:
A polarization photonic crystal fiber based on surface plasmon resonance is proposed in this paper. The photonic crystal fiber with gold coated holes is studied through using the finite element method. The impacts of structural parameters on the resonance characteristics are discussed. Numerical simulations show that the resonance wavelength can be modulated by changing the parameters of the air holes and thickness of gold layer. At the resonance wavelength 1550 nm, the loss is 3.8045 dB/m in x-polarization and the loss is 28464 dB/m in y-polarization by adjusting the size of the gold-coated holes and the place of air holes. Results show that the loss of y-polarized mode is much larger than the loss of x-polarized mode. The y-polarized mode is suppressed, and only x-polarized mode can be guided at the resonance wavelength of y-polarized mode. The results indicate that the mode polarized in one direction can be filtered out selectively by adjusting the diameter of air holes, and the filtering effect in a communication band is achieved.
Źródło:
Optica Applicata; 2018, 48, 4; 609-620
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Gradient flow optimization for reducing blocking effects of transform coding
Autorzy:
Gao, F.
Li, X.
Wang, X.
Wee, W. G.
Powiązania:
https://bibliotekanauki.pl/articles/907251.pdf
Data publikacji:
2004
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
przepływ gradientu
efekt blokowania
kodowanie transformatowe
gradient flow
blocking effects
optimization
transform coding
Opis:
This paper addresses the problem of reducing blocking effects in transform coding. A novel optimization approach using the gradient flow is proposed. Using some properties of the gradient flow on a manifold, an optimized filter design method for reducing the blocking effects is presented. Based on this method, an image reconstruction algorithm is derived. The algorithm maintains the fidelity of images while reducing the blocking effects. Experimental tests demonstrate that the presented algorithm is effective.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2004, 14, 1; 105-111
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Tight focusing of radially polarized beams by a devil’s vortex lens
Autorzy:
Chen, Z.
Hu, X.
Chen, X.
Wang, X.
Pu, J.
Powiązania:
https://bibliotekanauki.pl/articles/173576.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
devil’s vortex lens
radially polarized beam
tight focusing
high numerical aperture
Opis:
Tight focusing of radially polarized beams with a devil’s vortex lens is numerically investigated. Multiple focal spots can be generated in the geometric focus when a radially polarized beam is focused by a high numerical aperture objective in the presence of a devil’s vortex lens. The position of the major focal spot shifts from the geometric focus when a devil’s vortex lens with S = 1 is employed, and the position of the focal spot can be controlled by the numerical aperture of the objective. The intensity components of the major focal spot are influenced by the vortex phase of the devil’s vortex lens. A strong longitudinal component near the optical axis is produced by a devil’s vortex lens without vortex phase, and a nearly pure transversal field is produced by a devil’s vortex lens with vortex phase.
Źródło:
Optica Applicata; 2018, 48, 3; 389-398
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation and Characterisation of PSA/CNT Composites and Fibres
Wytwarzanie i charakteryzacja kompozytów polisulfonamidowych z udziałem nanorurek węglowych oraz wytworzonych z nich włókien
Autorzy:
Chen, Z.
Xin, B.
Wu, X.
Wang, X.
Du, W.
Powiązania:
https://bibliotekanauki.pl/articles/232490.pdf
Data publikacji:
2012
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
polysulfonamide
nanorurki węglowe
nanokompozyty
własności termiczne
przewodność elektryczna
carbon nanotube
nanocomposites
thermal property
electrical conductivity
Opis:
In this paper, polysulfonamide/carbon nanotube (PSA/CNT) composite solutions with different CNT contents were prepared using the physical blending method. Corresponding composite fibers were extruded and fabricated through a set of wet spinning units, and composite membranes were prepared by the spin-coating method. The PSA/CNT composite fibers and membranes were characterised by means of SEM, FTIR and XRD among others. The mechanical, thermal and electrical properties were also analysed in this study. The experimental results show that CNT at low contents can be distributed homogeneously in the PSA matrix. Furthermore the molecular structure and chemical composition of PSA does not undergo an obvious change. Crystallisation in the PSA can be promoted at low CNT contents because the nano-particles can act as a nucleation agent. Moreover the electrical conductivity of PSA can be improved significantly by the blending of CNT.
Przygotowano szereg zestawów polisulfonamidu i różnej ilości nanorurek węglowych. Z przygotowanego kompozytu wyprodukowano włókna i folie, które zostały scharakteryzowane przez skaningową mikroskopię elektronową, spektroskopię w podczerwieni i dyfrakcję rentgenowską. Analizowano również właściwości mechaniczne, przewodność cieplną i elektryczną otrzymanych próbek. Wyniki wskazują, że przy małym stężeniu nanorurek węglowych mogą one być rozprowadzone jednorodnie w całej matrycy; struktura molekularna i właściwości matrycy PSA nie ulegają zmianie; krystalizacja w matrycy PSA inicjowana jest przez nanorurki; przewodność elektryczna kompozytu zależy w dużym stopniu od ilości dodanych nanorurek.
Źródło:
Fibres & Textiles in Eastern Europe; 2012, 5 (94); 21-25
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis and Characterization of PolyNIMMO-HTPB-polyNIMMO Triblock Copolymer as a Potential Energetic Binder
Autorzy:
Wang, X.
Shu, Y.
Lu, X.
Mo, H.
Xu, M.
Powiązania:
https://bibliotekanauki.pl/articles/358529.pdf
Data publikacji:
2018
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
triblock copolymer
cationic ring opening polymerization
polymer
DSC
Opis:
Triblock copolymer polyNIMMO-HTPB-polyNIMMO was synthesized by cationic ring opening polymerization of NIMMO (3-nitratomethyl-3-methyloxetane) in the presence of hydroxyl-terminated polybutadiene catalyzed by BF3·OEt2. The polymer was characterized by FT-IR, 1H NMR, 13C NMR spectroscopy, and GPC. DSC was used to investigate the thermal behaviour of the triblock copolymer and its exothermic decomposition peak was found to be at 215 °C. All of the results indicated that the triblock copolymer polyNIMMO-HTPB-polyNIMMO might serve as a potential energetic propellant binder.
Źródło:
Central European Journal of Energetic Materials; 2018, 15, 3; 456-467
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Trophic connectivity between intertidal and offshore food webs in Mirs Bay, China
Autorzy:
Ning, J.
Du, F.
Wang, X.
Wang, L.
Li, Y.
Powiązania:
https://bibliotekanauki.pl/articles/47613.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
intertidal zonation
offshore zone
food web
different habitat
trophic interaction
stable isotope
carbon isotope composition
Mirs Bay
China
Źródło:
Oceanologia; 2019, 61, 2
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Distribution and role of the genus Oithona (Copepoda: Cyclopoida) in the South China Sea
Autorzy:
Wang, L.
Du, F.
Wang, X.
Li, Y.
Ning, J.
Powiązania:
https://bibliotekanauki.pl/articles/47786.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
Oithona
Copepoda
Cyclopoida
temperature
hydrological factor
phytoplankton
ichthyoplankton
South China Sea
Oithona plumifera
Oithona similis
Opis:
The relationships between the small cyclopoid copepod Oithona and hydrological factors, phytoplankton and ichthyoplankton were evaluated using the data obtained in the central South China Sea (SCS) in summer 2014. The genus abundance ranged from 6.00 ind. m3 to 93.75 ind. m3 with high abundance band occurring in the branch of SCS Monsoon Jet. The lower temperature and higher salinity in the surface water of the band than other zones indicated that deep water intrusion was a positive factor for aggregation of the genus. The community structure of the genus was dominated by Oithona plumifera and Oithona similis made up 97% of the genus abundance associated with Oithona tenuis. The result of db-RDA analysis showed that the community structure of the genus was affected by temperature, Chl a, larval fishes and fish spawns, and temperature was the most important limiting factor. The result of GAMs analysis showed that abundance of O. tenuis, and copepodites were affected by Chl a, larval fishes and fish spawns; abundance of O. similis was affected by Chl a and fish spawns; and abundance of O. plumifera was affected by Chl a and larval fishes. Therefore, we suggest that the branch of SCS Monsoon Jet and deep water intrusion favor aggregation of plankton in the central SCS in summer. We confirm that the temperature is the limiting factor to the reproduction of the genus Oithona in tropic seas and the genus Oithona is a food-web linker between primary production and larval fishes in the central SCS.
Źródło:
Oceanologia; 2017, 59, 3
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A method for probing the refractive index change in photorefractive crystals
Autorzy:
Fu, M.
Gao, C.
Wang, X.
Cui, Y.
Dai, S
Powiązania:
https://bibliotekanauki.pl/articles/174913.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
Fourier transform profilometry
refractive index change
photorefractive effect
Opis:
A method for probing refractive index changes in photorefractive crystals using an interferometric technique and digital image processing was proposed. Based on equal thickness interference in LiNbO3 crystal and Fourier transform profilometry, we obtained phase value changes in interferograms induced by a photorefractive effect, and further calculated refractive index changes. The maximal values for extraordinary light (e-light) and ordinary light (o-light) are 6.6×10–4 and 1.2×10–4, respectively.
Źródło:
Optica Applicata; 2013, 43, 4; 731-737
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The endomycorrhizal fungal species and their effects on the growth and nutrient characteristics of Eucalyptus maidenii seedlings in China
Autorzy:
Wang, X.
Kong, X.
Zhao, Y.
Cao, Y.
Cao, Z.
Powiązania:
https://bibliotekanauki.pl/articles/2077654.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
Eucalyptus maidenii
endomycorrhizal fungi
major species
Opis:
Eucalyptus maidenii plantations are typically fertilized to increase the yields of eucalyptus oil and timber. However, the application of chemical fertilizers is costly and can cause environmental pollution and soil erosion. Mycorrhiza fungi can facilitate the cultivation of optimal seedlings while promoting the growth of trees. To date, investigations into the inoculation of endomycorrhizal fungi to enhance the productivity of E. maidenii in Yunnan, China have not been undertaken. The species/dominant species of endomycorrhizal fungi on E. maidenii in Yunnan were isolated and iden- tified. The effect of endomycorrhizal fungi on E. maidenii was elucidated. The major species of endomycor- rhizal fungi that affect E. maidenii were ascertained. Bulk soil was collected from an E. maidenii plantation, and the species of endomycorrhizal fungi were inves- tigated. The effect of the endomycorrhizal fungi on E. maidenii were analyzed via a single factor experimental design, where the number of spores of endomycorrhizal fungi in the seedling substrate were controlled. The major endomycorrhizal fungi species that affected E. maidenii were ascertained via stepwise regression analysis. Five endomycorrhizal fungal species were isolated from the bulk soil, with the dominant being Glomus ag- gregatum and Glomus mosseae. With higher counts of endomycorrhizal fungal spores in the seedling substrate, the infection rate and intensity of seedlings were observed to increase, as well as the NPK concentrations of the bulk soil. With the increased nitrogen concentration in the bulk soil, the nitrogen concentration of the aerial components of the seedlings also increased. The NPK concentrations in the bulk soil and seedlings, the second order lateral roots, the root activity, and the seedling height were significantly promoted by the presence of endomycorrhizal fungi (the third experimental treatment). The NPK concentrations of the bulk soil and seedlings, as well as the growth indices of seedlings increased through endomycorrhizal fungi inoculation. The major species of the endomycorrhizal fungi on E. maidenii were G. aggregatum, Glomus multicaule, and Claroideoglomus etunicatum.
Źródło:
Dendrobiology; 2020, 83; 68-74
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
AE test of calcareous sands with particle rushing
Autorzy:
Tan, F.
Wang, X.
Hu, M.
Wang, R.
Zhu, C.
Powiązania:
https://bibliotekanauki.pl/articles/259886.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
calcareous sands
accoustic emission
conventional triaxial
consolidated undrained
AE signal
particle crushing
Opis:
The particle of calcareous sands was forced to crush, then the energy from the crushing was released by the form of sound waves. Therefore the AE technique was used to detect the calcareous sands AE signal when it crushed. by to study the AE characteristics, the mechanics of calcareous sands was studied. Study showed that: (1) there was the AE activities on the low confining pressure condition at the beginnig of test, (2) there was more and more AE activities with the continuing of test until to the end, (3) the calcareous sands’ AE activities was on the whole testing, (4) the calcareous sands’ particle crushing and mutual friction played different roles for its AE activities. Then the AE model based on the calcarous sands’ particle crushing was discussed.
Źródło:
Polish Maritime Research; 2017, S 2; 118-124
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stability of air nucleus in liquid water and cavitation inception on marine engineering
Autorzy:
Fu, Q.
Chen, M.
Wang, X.
Zhu, R.
Zhang, G.
Powiązania:
https://bibliotekanauki.pl/articles/260137.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
air nuclei
water
molecular dynamics
stability
surface tension
Opis:
The micro air nucleus widely distributed in the ocean is a necessary condition for the cavitation of hydraulic machinery in seawater. In order to study the stability of air nucleus in seawater and cavitation inception, the computational domain of water molecules with air nucleus was studied using the method of molecular dynamics simulation, and the transient characteristics of air nucleus in liquid water were obtained. The key factors influencing nuclei stability were analyzed. The results showed that air nucleus with a certain mass could maintain the dynamic equilibrium in liquid water. The internal density of air nuclei had a critical value that allowed the nuclei to stably exist in water. The air nuclei mass was the decisive factor in its equilibrium volume in water, and the two were positively correlated. The internal density of air nuclei was negatively correlated with the nuclei radius when the nuclei was stable in water. Liquid surface tension was an important factor affecting the stability of the air nuclei. The larger the initial radius of nuclei, the smaller the water pressure, and the more likely the cavitation occurs.
Źródło:
Polish Maritime Research; 2018, S 3; 111-119
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analytical Descriptions of Dynamic Softening Mechanisms for Ti-13Nb-13Zr Biomedical Alloy in Single Phase and Two Phase Regions
Autorzy:
Quan, G.-Z.
Wang, X.
Li, Y.-L.
Zhang, L.
Powiązania:
https://bibliotekanauki.pl/articles/353917.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
biomedical titanium alloy
flow stress
dynamic recovery
dynamic recrystallization
dynamic softening
Opis:
Dynamic softening behaviors of a promising biomedical Ti-13Nb-13Zr alloy under hot deformation conditions across dual phase α + β and single phase β regions were quantitatively characterized by establishing corresponding dynamic recovery (DRV) and dynamic recrystallization (DRX) kinetic models. A series of wide range hot compression tests on a Gleeble-3500 thermo-mechanical physical simulator were implemented under the strain rate range of 0.01-10 s−1 and the temperature range of 923-1173 K. The apparent differences of flow stress curves obtained in dual phase α + β and single phase β regions were analyzed in term of different dependence of flow stress to temperature and strain rate and different microstructural evolutions. Two typical softening mechanisms about DRV and DRX were identified through the variations of a series of stress-strain curves acquired from these compression tests. DRX is the dominant softening mechanism in dual phase α + β range, while DRV is the main softening mechanism in single phase β range. The DRV kinetic model for single phase β region and the DRX kinetic model for dual phase α + β region were established respectively. In addition, the microstructures of the compressed specimens were observed validating the softening mechanisms accordingly.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 4; 2029-2043
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mechanical Spectroscopy of Equal-Channel Angular Pressed Fe-Cr Alloys and Tungsten
Spektroskopia mechaniczna stopów Fe-Cr i wolframu wyciskanych przez kanał kątowy
Autorzy:
Hao, T.
Tang, H.
Jiang, W.
Wang, X.
Fang, Q.
Powiązania:
https://bibliotekanauki.pl/articles/352822.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
mechanical spectroscopy
internal friction technique
Fe-18wt.%Cr alloy and pure W
equal-channel angular
spektroskopia mechaniczna
technika tarcia wewnętrznego
stop Fe-18wt%Cr i czystego W
kanał kątowy
Opis:
nternal friction technique was used to investigate the microstructural stability of equal-channel angular pressed (ECAP) 9Cr1Mo steel (T91), Fe-18wt.%Cr alloy, and pure W. Several non-relaxation internal friction peaks are observed in three ECAP-strained specimens, which are related to the microstructural transition from a severely deformed state to a static recovery state of dislocations, and to recrystallized state. Along with the disappearance of the P1 peak, another relaxation internal friction peak P2 is observed during the second heating run only in Fe-18wt.%Cr alloy, and it does not disappear even during subsequent third heating run. This peak is not observed in T91 steel and W. The P2 peak is likely associated with a process of grain boundary (GB) sliding. Unlike T91, no abundant carbide precipitates distribute on GBs to pin GB and repulse GB sliding, thus, the P2 peak only occurs in Fe-18wt.%Cr alloy. It is concluded that high-temperature internal friction measurements are required to detect the grain boundary peak in pure W.
Technika tarcia wewnętrznego została użyta do zbadania stabilności mikrostruktury poddanych wyciskaniu przez kanał kątowy stali 9Cr1Mo (T91), stopu Fe-18wt%Cr, i czystego W. Zaobserwowano wiele nie-relaksacyjnych pików tarcia wewnętrznego w trzech próbkach odkształconych przez ECAP, które są związane z przejściem ze stanu silnie odkształconego do statycznego stanu zdrowienia dyslokacji, i do stanu zrekrystalizowanego. Wraz z zanikiem piku P1, tylko w przypadku stopu Fe-18wt%Cr obserwowany jest inny pik P2 relaksacji tarcia wewnętrznego podczas drugiego ogrzewania, i nie znika nawet w kolejnym trzecim etapie ogrzewania. Pik ten nie jest obserwowany w stali T91 i W. Pik P2 prawdopodobnie związany jest procesem poślizgu granicy ziaren. W przeciwieństwie do stali T91, brak bogatych w węglik wydzieleń na granicach ziaren, które by unieruchomiły granice i uniemożliwiły poślizg, stąd pik P2 występuje tylko w przypadku stopu Fe-18wt.%Cr. Stwierdzono, że pomiary tarcia wewnętrznego w wysokiej temperaturze są potrzebne, aby wykryć pik granicy ziarna w czystym W.
Źródło:
Archives of Metallurgy and Materials; 2015, 60, 3A; 2101-2106
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of fenugreek-gum and particle size on performance of talc flotation
Autorzy:
Gu, G.
Mo, C.
Zhao, K.
Chen, Z.
Wang, X.
Powiązania:
https://bibliotekanauki.pl/articles/109940.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
talc
particle size
fenugreek-gum
depression
flocculation
Opis:
Talc usually exists as a gangue mineral in copper-nickel sulfide, molybdenite etc. In order to separate precious metals, naturally hydrophobic talc should be depressed effectively in flotation process. The effect of fenugreek-gum (FG) on the flotation performance of talc with different particle sizes was studied. The depression mechanism was investigated extensively through tests of flotation, adsorption and zeta potential, as well as infrared spectroscopy and laser particle size analysis. Flotation results indicated that the FG had a strong depression ability for talc with the particle size of -0.074 + 0.037 mm, -0.037 mm and -0.010 mm when proper dosage of FG was added. The coarse talc was completely depressed by 2.5 mg/ dm3 FG. When the particle size decreased, more FG was required to obtain the maximum depressing effect, which was verified by adsorption tests. FG reduced the electronegativity on the talc surface by chemical adsorption, and flocculation of talc powders caused a high efficient depressing effect.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 3; 1026-1033
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of oxidation on the wetting of coal surfaces by water: experimental and molecular dynamics simulation studies
Autorzy:
Li, E.
Lu, Y.
Cheng, F.
Wang, X.
Miller, J. D.
Powiązania:
https://bibliotekanauki.pl/articles/109792.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
wettability
oxidation
molecular dynamics simulation
hydrogen bonding
contact angles
coal surfaces
Opis:
The wettability of coal surfaces by water continues to be one of the key factors which determines the success of coal flotation. Consequently, oxidation of coal surfaces is a fundamental issue of interest. In this work, the effect of oxidation on the wetting of coal surfaces and the interaction between water molecules and oxygen-containing sites at the coal surface was investigated based on advancing/receding contact angle measurements and molecular dynamics simulations. For the simulation studies, a flat coal surface was constructed with the assistance of the molecular repulsion between graphite surfaces and the assembly of Wiser coal molecules. Our results indicated that the simulated advancing and receding contact angles were very similar, and both of them decreased, as expected, with an increase of hydroxyl sites at the coal surface. The good agreement between the simulated advancing/receding contact angles and the experimental receding contact angle values suggested that the configuration of the systems and the set of parameters for the simulation were appropriate. The spreading of water is mainly due to the hydrogen bonds formed between the interfacial water molecules and the hydroxyl sites at the coal surface. The hydroxyl groups show stronger hydration capacity than other oxygen-containing groups according to the calculated hydrogen bonds and interaction energies.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 4; 1039-1051
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A euenantiornithine bird from the Late Cretaceous Hateg Basin of Romania
Autorzy:
Wang, X.
Dyke, G.J.
Codrea, V.
Godefroit, P.
Smith, T.
Powiązania:
https://bibliotekanauki.pl/articles/21454.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Opis:
We present the first record of a euenantiornithine bird from Romania. A small collection of fossil remains from the Maastrichtian add to the known distribution of large euenantiornithines and descriptions of birds from the Haţeg Basin augment the known vertebrate fauna from this famous region of Transylvania. The new specimens referred here to an indeterminate taxon of euenantiornithine further demonstrate that the larger members of this diverse Cretaceous lineage were globally distributed, as many birds are today.
Źródło:
Acta Palaeontologica Polonica; 2011, 56, 4
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Piezoelectric effect on thermoelastic Lamb waves in functionally graded plates
Autorzy:
Wang, X.
Ren, X.
Yu, J.
Zhou, H.
Zhang, X.
Leng, J
Powiązania:
https://bibliotekanauki.pl/articles/38695708.pdf
Data publikacji:
2023
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
thermoelastic wave
attenuation
FGM
piezoelectric effect
physical field distributions
Opis:
Based on the Lord–Shulman thermoelectric elasticity theory, the piezoelectric effect on the thermoelastic Lamb wave propagation in the functionally graded material (FGM) plate is investigated. The coupled wave equations are solved by employing the Legendre polynomial series approach (LSPA), which poses the advantages of small scale of eigenvalues matrix and a convenient solution. It can directly obtain the complex wave number solutions without iteration. The obtained complex solutions, which represent the wave propagation and attenuation, are compared with those available data. Numerical examples show that the influence of gradient is profound. Results indicate that the piezoelectric effects on attenuation with the open and closed circuit condition are consistent for the S0 and S1 modes, but are inconsistent for the A0 and A1 modes. Although the piezoelectric effect is weak on the dispersion and attenuation of thermal waves, it is notable for their physical field distributions. In addition, the relaxation time is critical to electric displacements of a thermal wave mode, but is not essential for those of Lamb-like modes. The results can be used for the optimization of thermo-electric-elastic coupling structures.
Źródło:
Archives of Mechanics; 2023, 75, 1-2; 3-26
0373-2029
Pojawia się w:
Archives of Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Solution Growth of Well-Aligned ZnO Nanorods on Sapphire Substrate
Autorzy:
Jia, G.
Hao, B.
Lu, X.
Wang, X.
Li, Y.
Yao, J.
Powiązania:
https://bibliotekanauki.pl/articles/1399510.pdf
Data publikacji:
2013-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
68.37.Yz
78.40.Fy
68.55.J-
Opis:
Vertically well-aligned ZnO nanorods arrays were synthesized on sapphire substrates by chemical bath deposition. Those sapphire substrates were seeded to control the density and orientation of ZnO nanorods using sol-gel method. Well-aligned and uniformly distributed ZnO nanorods in a large scale were obtained with strongly (002) preferential orientation. The structural properties were characterized by X-ray diffraction spectrometer and morphological characteristics were analyzed by scanning electron microscopy, respectively. The ZnO nanorods are obvious hexangular wurtzite structure and preferentially oriented along the c-axis (002) and growth vertically to the substrates. The optical properties were further thoroughly studied. What is more, the influences of the strain between substrate and ZnO nanorods due to thickness of the ZnO seed-layer on the characteristics and optical properties of ZnO were also analyzed.
Źródło:
Acta Physica Polonica A; 2013, 124, 1; 74-77
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Adsorption efficiency of pentafluorobenzene on ionic liquids-based silicas
Autorzy:
Wang, X.
Lin, L.
Xie, J.
Yan, X.
Xiao, W.
Tian, P.
Powiązania:
https://bibliotekanauki.pl/articles/778559.pdf
Data publikacji:
2018
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
ionic liquids based silica
pentafl uorobenzene
adsorption
solid-phase extraction
Opis:
The adsorption of pentafl uorobenzene on nine ionic liquid-based silicas was investigated using solid phase extraction. The effects of several variables such as the type of ionic liquid groups, adsorption time, temperatures and water ratio in the solution system were experimentally evaluated. The imidazole-chloride ionic liquid group based silica exhibited the highest adsorption efficiency under the optimized conditions of 5 min adsorption at 30°C in water/methanol (30:70, vol%) solution. In addition, the effects of pH, as well as type and concentrations of chloride salts were investigated. At pH values other than neutral and high salt concentration, the adsorption efficiency was reduced. Finally, the relative standard deviation of less than 5.8% over a 5-day period showed a high precision for the nine tested sorbents.
Źródło:
Polish Journal of Chemical Technology; 2018, 20, 3; 47-52
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Chitosan Modified Corn Starch and Its Application as a Glass Fibre Sizing Agent
Skrobia kukurydziana modyfikowana chitozanem i jej zastosowanie jako środka klejącego włókien szklanych
Autorzy:
Wang, Y.
Li, J.
Li, H.
Wang, X.
Lei, H.
Huo, J.
Powiązania:
https://bibliotekanauki.pl/articles/232005.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
glass fiber
sizing agent
corn starch
chitosan
modification
włókno szklane
środki klejące
skrobia kukurydziana
chitozan
modyfikacja
Opis:
Chitosan-modified corn starch was prepared and then applied as a glass fiber sizing agent. The effect of the chitosan on starch-based emulsion, film and sized glass fiber was studied. When 5 % of the chitosan was added, the overall performance of the modified film-forming agent was optimal. The viscosity, surface tension and zeta potential of the sizing agent were 44.99 mPa·s, 51.29 mN·m-1 and 4.5 mV, respectively. The modified sizing agent could easily spread over the surface of glass fibre, and conglutinated to the glass surface firmly. The tensile strength and stiffness of modified-starch glass fiber reached 0.43 N·tex-1 and 4.96 cm. Glass fiber with good overall performance was obtained.
W pracy przygotowano skrobię kukurydzianą modyfikowaną chitozanem, a następnie zastosowano ją jako środek klejący włókien szklanych. Określono lepkość, napięcie powierzchniowe i potencjał zeta środka klejącego. Zmierzono wytrzymałość na rozciąganie i sztywność zmodyfikowanego włókna szklanego. Stwierdzono, że modyfikacja skrobi chitozanem powoduje poprawienie jej właściwości jako środka klejącego. Modyfikacja zwiększyła przyczepność skrobi do włókien i poprawiła ich właściwości mechaniczne.
Źródło:
Fibres & Textiles in Eastern Europe; 2017, 3 (123); 112-120
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fiber-optic accelerometer based on a modal interferometer using a thin-core fiber
Autorzy:
Wang, X
Wu, X
Li, S
Ge, Q
He, T
Yu, B
Powiązania:
https://bibliotekanauki.pl/articles/174927.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
fiber-optic accelerometer
modal interferometer
thin-core fiber
Opis:
A compact fiber-optic accelerometer based on a modal interferometer, which is fabricated by misaligned splicing of a short section of a thin-core fiber between two sections of a standard single-mode fiber, is demonstrated experimentally. A spectrum analysis method is used to detect an acceleration signal rapidly. The experimental results show that the thin-core fiber-based fiber-optic accelerometer has a minimum detectable acceleration of 3.3×10–3g (g – gravitational acceleration), and a wide frequency response range from 10 to 1200 Hz. Moreover, the proposed accelerometer exhibits the advantages of low cost, simple structure and easy fabrication.
Źródło:
Optica Applicata; 2015, 45, 3; 317-325
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Unidirectional Torsion Properties of Single Silk Fibre
Właściwości monowłókien jedwabnych przy jednokierunkowym skręcaniu
Autorzy:
Jiang, S.
Cao, G.
Cai, G.
Xu, W.
Li, W.
Wang, X.
Powiązania:
https://bibliotekanauki.pl/articles/232187.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
unidirectional torsion
silk fibre
fracture angle
breaking cycle
SEM
XRD
skręcanie jednokierunkowe
włókno jedwabne
badania
Opis:
The unidirectional torsion properties of silk fibre were investigated on a purpose-built single fibre torsion tester. The torsional fracture angle and the number of cycles of torsion at breaking were recorded, and the effect of the gauge length and pretension together with the torsion speed on the torsion properties of single silk fibre was investigated in detail. Scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis and a tensile tester were used to understand the morphology, structure and tensile properties of silk fibre after torsion deformation. SME photos show that silk fibre exhibits a ribbon-like profile after torsion, and fracture tends to occur at both ends of the silk fibre, where a larger number of twists can be observed. The crystallinity calculated from XRD spectra of silk fibre increases from 26.11% to 34.10% after torsion. The breaking stress and strain decreases slightly with an increase in the gauge length. The breaking cycle increases linearly with an increase in the gauge length, while the actual torsional fracture angle decreases gradually at the same time. The torsional fracture angle together with the breaking cycle decreases gradually as the pretension increases. The fracture angle together with the breaking cycle increases with an increase in the torsion speed. Understanding the unidirectional torsion properties of single silk fibre will benefit its further application in specific areas where the fibre will be subject to frequent torsion and deformation.
Badania przeprowadzono za pomocą specjalnie zbudowanego urządzenia do badania skrętu włókien. Badano kąt przełomu oraz ilość cykli doprowadzających do zerwania. Sprawdzano również wpływ długości próbki oraz wstępnego naprężenia. Oceniono wpływ długości próbki wstępnego naprężenia, szybkości skrętu na właściwości wytrzymałościowe włókien jedwabnych. Stosowano SEM, XRD dla określenia morfologii i struktury włókien. Stwierdzono, że włókna jedwabne po badaniu wykazują formę podobną do taśmy. Na podstawie XRD stwierdzono, że krystaliczność wzrasta od ok. 26% do 34% po skręceniu. Naprężenie zrywające i odkształcenia zmniejszają się lekko przy wzroście długości próbki.
Źródło:
Fibres & Textiles in Eastern Europe; 2016, 3 (117); 26-30
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Parameter Description of the Surface Metal Fiber Arrangement of Electromagnetic Shielding Fabric
Wpływ rozmieszczenia włókien metalowych na skuteczność ekranowania tkanin osłonowych
Autorzy:
Liu, Z.
Su, Y.
Pan, Z.
Li, Y.
Wang, X.
Zhou, Z.
Powiązania:
https://bibliotekanauki.pl/articles/232915.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
electromagnetic shielding fabric
surface metal fiber blends
surface metal arrangement
tkanina ekranująca
tkanina osłonowa elektromagnetyczna
układ metalowy powierzchni
Opis:
The influence of the surface metal fiber (SMF) arrangement on the shielding effectiveness (SE) of electromagnetic shielding fabric (EMSF) is important, but there is no reasonable description method for it at present, making the further exploration of the relationship between SMF and SE difficult. In order to scientifically describe the SMF arrangement of EMSF, this paper constructs a binary feature matrix of SMF based on a previous study of SMF region recognition. According to the feature matrix, three parameters of the exposure ratio, the discrete mean and disorder degree are proposed and the calculation equations for the three parameters given. Experiments were designed and testing samples determined to test the SE, and the exposure ratio, discrete mean and disorder degree of each sample are calculated. The relationship between the three parameters and the SE is analysed for effectiveness validation of the three parameters. Results show that the exposure ratio, discrete mean and disorder degree can describe three aspects of the SMF arrangement: the percentage content, porosity and orientation, which are positively correlated, negatively correlated and positively correlated to the SE, respectively. The research in this paper provides a basis for the study of the shielding mechanism, the transmission model, the shielding rule and the rapid non-destructive evaluation of the EMSF, and puts forward a new idea for the study of shielding theory and the application of the EMSF.
Ze względu na istotny wpływ rozmieszczenia włókien metalowych (SMF) na skuteczność ekranowania (SE) tkanin osłonowych (EMSF) w pracy przedstawiono macierz binarną opartą na trzech parametrach włókien metalowych tj.: współczynniku ekspozycji, średniej wartości odległości między włóknami metalowymi i stopniu ich nieuporządkowania. Analizowano zależności pomiędzy wyżej wymienionymi parametrami a skutecznością ekranowania. Przedstawione wyniki stanowią podstawę do opracowania szybkiej i nieniszczącej metody oceny skuteczność ekranowania oraz do dalszych badań mechanizmu ekranowania.
Źródło:
Fibres & Textiles in Eastern Europe; 2017, 2 (122); 62-67
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Early Cambrian origin of thylacocephalan arthropods
Autorzy:
Vannier, J
Chen, J.Y.
Huang, D.Y.
Charbonnier, S.
Wang, X.Q.
Powiązania:
https://bibliotekanauki.pl/articles/23320.pdf
Data publikacji:
2006
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
fauna
thylacocephalan arthropod
Lagerstatte
Zhenghecaris shankouensis
China
arthropod
Arthropoda
Early Cambrian
Cambrian
paleontology
Opis:
Zhenghecaris shankouensis gen. et sp. nov. is one of the largest “bivalved” arthropods of the Lower Cambrian Maotianshan Shale fauna. Its non−mineralized carapace was dome−like, laterally compressed, armed with rostral features, and probably enclosed the entire body of the animal. Zhenghecaris was provided with elliptical stalked lateral eyes. The carapace design, external ornament and visual organs of Zhenghecaris suggest affinities with the Thylacocephala, an extinct (Lower Silurian to Upper Cretaceous) group of enigmatic arthropods whose origins remain poorly understood. The bivalved arthropodsIsoxys and Tuzoia (Lower and Middle Cambrian) are two other potential thylacocephalan candidates making this group of arthropods a possible new component of Cambrian marine communities. Zhenghecaris, Isoxys, and Tuzoia are interpreted as nektonic animals that probably inhabited the lower level of the water column in shallow shelf settings at depths of perhaps 100–150 m or less. Their feeding mode either in the water column (e.g., mesozooplankton) or on the substrate (e.g., small epibenthos, detritus) is uncertain, although some of these arthropods were possibly mid−water predators (e.g., Isoxys with raptorial appendages).
Źródło:
Acta Palaeontologica Polonica; 2006, 51, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electronic System Fault Diagnosis with Optimized Multi-kernel SVM by Improved CPSO
Diagnoza uszkodzeń układu elektronicznego z wykorzystaniem Wielojądrowej Maszyny Wektorów Nośnych (SVM) zoptymalizowanej przy pomocy poprawionego algorytmu CPSO
Autorzy:
Guo, Y. M.
Wang, X. T.
Liu, C.
Zheng, Y. F.
Cai, X. B.
Powiązania:
https://bibliotekanauki.pl/articles/300922.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
układ elektroniczny
diagnoza uszkodzeń
maszyna wektorów nośnych
optymalizacja metodą chaosu-roju cząstek
funkcja wielojądrowa
electronic system
fault diagnosis
support vector machine (SVM)
chaos particles swarm optimization
multi-kernel
Opis:
Bezpieczeństwo pracy układów elektronicznych stało się kluczowym zagadnieniem w odniesieniu do złożonych układów o wysokiej niezawodności. Obecnie coraz większy nacisk kładzie się na trafność diagnozy uszkodzeń układów elektronicznych. Na podstawie charakterystyki diagnozy uszkodzeń układów elektronicznych, opracowaliśmy model wielokryterialnej klasyfikacji SVM pozwalający osiągnąć lepszą trafność diagnozy uszkodzeń. Model wykorzystuje funkcję wielojądrową składającą się z kilku bazowych funkcji jądrowych pozwalającą na zwiększenie interpretowalności modelu klasyfikacyjnego. Aby zoptymalizować działanie modelu wielokryterialnej klasyfikacji SVM wykorzystującego funkcję wielojądrową, udoskonaliliśmy algorytm Optymalizacji Metodą Chaosu-Roju Cząstek (CPSO), co pozwoliło osiągnąć optymalne parametry SVM i funkcji wielojądrowej. W poprawionym algorytmie CPSO wzmocniono różnorodność wyszukiwania poprzez wykorzystanie chaotycznej sekwencji generowanej przez zmodyfikowaną mapę tent, a także włączono do standardowego algorytmu PSO efektywną metodę pozwalającą uniknąć przedwczesnej stagnacji oraz uzyskać globalne wartości optymalizacji. Wyniki symulacji diagnozy uszkodzeń systemu elektronicznego pokazują, że proponowany system optymalizacji może być wykorzystywany jako skuteczna metoda umożliwiająca znaczne zwiększenie trafności diagnozy uszkodzeń z wykorzystaniem wielojądrowej SVM.
Electronic systems’ safety operation has become a key issue to complex and high reliability systems. Now more emphasis has been laid on the accuracy of electronic system fault diagnosis. Based on the characteristics of the electronic system fault diagnosis, we design a multi-classification SVMs model to attain better fault diagnosis accuracy, which utilizes multi-kernel function consisting of several basis kernel functions to enhance the interpretability of the classification model. In order to optimize the performance of multi-classification SVMs with multi-kernel, we improve the Chaos Particles swarm Optimization (CPSO) algorithm to achieve the optimum parameters of SVMs and the multi-kernel function. For the improved CPSO algorithm, a modified Tent Map chaotic sequence is used to strengthen the search diversity, and an effective method is embedded to the stander PSO algorithm which can ensure to avoid premature stagnation and obtain the global optimization values. The fault diagnosis simulation results of an electronic system show the proposed optimization scheme is a feasible and effective method and it can significantly improve the fault diagnosis accuracy of the multi-kernel SVM.
Źródło:
Eksploatacja i Niezawodność; 2014, 16, 1; 85-91
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dispersive effect of low molecular weight sodium polyacrylate on pyrite-serpentine flotation system
Autorzy:
Zhao, K.
Yan, W.
Wang, X.
Gu, G.
Deng, J.
Zhou, X.
Hui, B.
Powiązania:
https://bibliotekanauki.pl/articles/110158.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
dispersant
serpentine
flotation
surface potential
dispersion mechanism
Opis:
In this work, the dispersive effect of low molecular weight sodium polyacrylate (PAAS) on serpentine, and its dispersion mechanism were systematically investigated through zeta potential measurements, micro and batch flotation as well as adsorption tests. At pH 5, where flotation of iron sulphide was routinely performed, pyrite and serpentine minerals were oppositely charged, and therefore they were attracted to each other. Slime coatings of serpentine adhered to the surface of pyrite, decreasing the adsorption density of a collector on the pyrite surface, but also reducing the flotation recovery. PAAS increased the flotation recovery of pyrite by promoting dispersion between pyrite and serpentine. The effective flotation separation of pyrite from the refractory iron sulphide ore was possible by using PAAS as a dispersant. Anionic PAAS adjusted the surface potential of serpentine through adsorption on the serpentine surface and changed the interaction between pyrite and serpentine particles from attractive to repulsive, and then dispersed pyrite and serpentine.
Źródło:
Physicochemical Problems of Mineral Processing; 2017, 53, 2; 1200-1213
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Review of the Photodecomposition of Some Important Energetic Materials
Autorzy:
Sun, Y.
Shu, Y.
Xu, T.
Shui, M.
Zhao, Z.
Gu, Y.
Wang, X.
Powiązania:
https://bibliotekanauki.pl/articles/358397.pdf
Data publikacji:
2012
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
photodecomposition mechanisms
energetic materials
Opis:
The photodecomposition mechanisms of energetic materials vary with molecular structure, photodissociation wavelength, the phase of the material, experimental pressure and temperature etc. In this paper, the significant progress on photodecomposition studies of some important energetic materials achieved in recent years is introduced in detail, including nitromethane, DMNA (dimethylnitramine), TATB (1,3,5-triamino-2,4,6-trinitrobenzene), RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine), HMX (1,3,5,7-tetranitro-1,3,5,7- tetrazacycloctane) and CL-20 (2,4,6,8,10,12-hexanitrohexaazaisowurtzitane). The difficulties and prospects of photodecomposition research of energetic materials are also indicated.
Źródło:
Central European Journal of Energetic Materials; 2012, 9, 4; 411-423
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Visual Detection Method of Longitudinal Crack Based on Computer Image Processing During Slab Continuous Casting
Autorzy:
Liu, Y.
Wang, X.
Sun, Y.
Du, F.
Gao, Y.
Wang, F.
Wang, J.
Powiązania:
https://bibliotekanauki.pl/articles/351636.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
longitudinal crack
visual detection
image processing
continuous casting
Opis:
Based on the mould temperature measured by thermocouples during slab continuous casting, a difference of temperature thermograph is developed to detect slab cracks. In order to detect abnormal temperature region caused by longitudinal crack, the suspicious regions are extracted and divided by virtue of computer image processing algorithms, such as threshold segmentation, connected region judgement and boundary tracing. The abnormal regions are then determined and labeled with the eight connected component labeling algorithm. The boundary of abnormal region is also extracted to depict characteristics of longitudinal crack. Based on above researches, longitudinal crack with abnormal temperature region can be detected and is different from other abnormalities. Four samples of temperature drop are picked up to compare with longitudinal crack on the abnormal region formation, length, width, shape, et al. The results show that the abnormal region caused by longitudinal crack has a linear and vertical shape. The height of abnormal region is more than the width obviously. The ratio of height to width is usually larger than that of other temperature drop regions. This method provides a visual and easy way to detect longitudinal crack and other abnormities. Meanwhile it has a positive meaning to the intelligent and visual mould monitoring system of continuous casting.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 2; 673-680
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The irp2 and fyuA genes in High Pathogenicity Islands are involved in the pathogenesis of infections caused by avian pathogenic Escherichia coli (APEC)
Autorzy:
Tu, J.
Hue, T.
Qi, K.
Shao, Y.
Huang, B.
Wang, X.
Zhou, X.
Powiązania:
https://bibliotekanauki.pl/articles/30327.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Opis:
Avian pathogenic Escherichia coli (APEC) is a major bacterial infectious disease that may lead to local or systemic infections in chickens with clinical manifestations. The irp2-fyuA gene cluster has been confirmed to be the main genes involved in the synthesis of HPI. The objective of this study was to determine the influence of the irp2 and fyuA genes in the high pathogenicity island (HPI) of avian pathogenic Escherichia coli (APEC) on its pathogenicity by knocking out these genes. The ΔAE17 (lacking irp2) and ΔΔAE17 (lacking irp2 and fyuA) strains of APEC were constructed. The ΔAE17 and ΔΔAE17 strains showed significantly impaired capacity to adhere onto DF-1 cells. The LD50 results indicated that the virulence of the ΔAE17 and ΔΔAE17 strains was decreased in comparison with that of the AE17 strain. We concluded that the knock-out of the core HPI genes weakened APEC adhesion onto DF-1 cells, inhibited transcription of virulence genes, and reduced pathogenicity in chicks. The effects of genetic deletion of irp2 and fyuA on APEC were more severe than those produced by deletion of irp2 only, indicating that irp2 and fyuA co-regulate APEC pathogenicity.
Źródło:
Polish Journal of Veterinary Sciences; 2016, 19, 1
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Water film structure during rupture as revealed by MDS image analysis
Autorzy:
Truong, N. T.
Dang, L. X.
Lin, C.-L.
Wang, X.
Miller, J. D.
Powiązania:
https://bibliotekanauki.pl/articles/110251.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
image processing
molecular dynamics simulation
film stability
molecular porosity
Opis:
The structure of thin water films during the rupture process was investigated by a new approach, which combines molecular dynamics simulation (MDS) with image processing analysis. The analysis procedure was developed to convert MDS trajectories to readable 3D images. The water films were studied at different thicknesses by MDS to determine the critical thickness at which the film ruptures. The potential energy of each specific film thickness during the simulation time was analyzed, and the results showed that the potential energy of stable films remained unchanged while the potential energy kept decreasing for films which ruptured during the simulation time. By applying the new procedure, the molecular porosity, which is defined as the void fraction between the volume of molecular pores in the water film and the total volume of the water film, was calculated. The results of molecular porosity for different film thicknesses during the simulation time suggested a critical molecular porosity as 49%. In other words, stable films have a molecular porosity of less than 49%. If a water film has a molecular porosity greater than 49%, rupture occurs during the simulation.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 4; 1060-1069
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Genetic analysis of 38 double-flowered amaryllis (Hippeastrum hybridum) cultivars based on SRAP markers
Autorzy:
Xiong, M.
Yang, S.
Wang, Y.
Chen, D.
Wang, X.
Zhou, D.
Wei, Z.
Powiązania:
https://bibliotekanauki.pl/articles/12994499.pdf
Data publikacji:
2021
Wydawca:
Uniwersytet Przyrodniczy w Lublinie. Wydawnictwo Uniwersytetu Przyrodniczego w Lublinie
Źródło:
Acta Scientiarum Polonorum. Hortorum Cultus; 2021, 20, 3; 15-25
1644-0692
Pojawia się w:
Acta Scientiarum Polonorum. Hortorum Cultus
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Effect of Nb Content on the Thermal, Structural, and Magnetic Properties of FeNbB Ribbons
Autorzy:
Hua, Z.
Zuo, B.
Li, M.
Wang, X.
Wang, L.
Liu, J.
Wang, D.
Dong, L.
Powiązania:
https://bibliotekanauki.pl/articles/1365063.pdf
Data publikacji:
2014-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
65.60.+a
61.43.Dq
Opis:
Amorphous $Fe_{80-x}Nb_{x}B_{20}$ (x = 5, 10, 15) ribbons were prepared by single-roller melt spinning method. The thermal, structural and magnetic properties of $Fe_{80-x}Nb_{x}B_{20}$ (x = 5, 10, 15) ribbons were investigated using differential thermal analysis, X-ray diffraction, and vibrating sample magnetometer. The thermal stability is the lowest for $Fe_{70}Nb_{10}B_{20}$ ribbon and the highest for $Fe_{65}Nb_{15}B_{20}$ ribbon. Along with the increase of Nb content, the supercooled liquid region Δ $T_{x}$ increases, indicating that the amorphous formation ability improves. The primary stages of crystallization of the three ribbons are different. The primary devitrification phases are $Fe_{23}B_6$ type for $Fe_{70}Nb_{10}B_{20}$ and $Fe_{75}Nb_5B_{20}$ ribbons, and α-Fe type for $Fe_{65}Nb_{15}B_{20}$ ribbon. $Fe_{80-x}Nb_{x}B_{20}$ (x = 5, 10) ribbons are ferromagnetic and the $Fe_{65}Nb_{15}B_{20}$ ribbon is paramagnetic. The saturation magnetization ($M_{s}$) decreases with increasing Nb content.
Źródło:
Acta Physica Polonica A; 2014, 125, 5; 1149-1151
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Specific Heat of RBa$\text{}_{2}$Cu$\text{}_{3}$O$\text{}_{7-x}$ and RBaSrCu$\text{}_{3}$O$\text{}_{7-x}$ Compounds (R = Sm, Dy, Er)
Autorzy:
Tarnawski, Z.
Kim-Ngan, N.-T. H.
Wang, X. Z.
Duijn, V. H. M.
Franse, J. J. M.
Powiązania:
https://bibliotekanauki.pl/articles/1968860.pdf
Data publikacji:
1998-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
74.70.-b
75.40.-s
Opis:
The low-temperature specific-heat C(T) data of high-T$\text{}_{c}$ superconductors RBa$\text{}_{2}$Cu$\text{}_{3}$O$\text{}_{7-x}$(R123O$\text{}_{7-x}$) were reviewed. A discussion of the C(T) data obtained on single-crystalline samples of Er123O$\text{}_{7-x}$ and Sm123O$\text{}_{7-x}$ compounds in applied magnetic fields for better evaluation of the crystal-electric-field parameters is given. The C(T) measurements of Sr-substituted compounds RBaSrCu$\text{}_{3}$O$\text{}_{7}$ revealed the λ-type of peak related to the antiferromagnetic order at 1.2 K and 0.6 K respectively for Dy- and Er-compounds. The magnetic singlet ground state in these compounds is produced by weak exchange interactions of -0.05 T/μ$\text{}_{B}$ and -0.035 T/μ$\text{}_{B}$, respectively. For Nd- and Sm-compounds, only a broad anomaly around 0.6 K was observed which is well fitted with a Schottky-type anomaly with an energy splitting of 1.4 K.
Źródło:
Acta Physica Polonica A; 1998, 93, 3; 513-522
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
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:
MGF360-12L of ASFV-SY18 is an immune-evasion protein that inhibits host type I IFN, NF-κB, and JAK/STAT pathways
Autorzy:
Chen, Q.
Wang, X.X.
Jiang, S.W.
Gao, X.T.
Huang, S.Y.
Liang, Y.
Jia, H.
Zhu, H.F.
Powiązania:
https://bibliotekanauki.pl/articles/16647496.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
African swine fever virus
MGF360-12L
type I IFN
NF-κB
JAK/STAT
Opis:
African swine fever virus (ASFV) causes feverous and hemorrhagic disease of domestic pigs and European wild boars with high mortality, yet no commercial vaccine is currently available. Several ASFV strains with natural deletion or gene-targeted knockout of multiple MGF360 and MGF505 genes are attenuated in vitro and in vivo, and can offer full protection against homologous challenge. However, the mechanisms underlying the protection are not fully understood. This study aims to investigate the effects of MGF360-12L of ASFV-SY18 on the cGAS-STING signaling pathway and explore the potential mechanisms. We identified that ASFV-SY18 MGF360-12L could inhibit cGAS-STING, TBK1, or IRF3-5D-stimulated IFN-β expression and ISRE activation. Specifically, MGF360-12L inhibits both the activation of PRD(III-I) in a dose-dependent manner, and suppresses the exogenous expression of TBK1 and IRF3-5D. MGF360-12L could block NF-κB activation induced by overexpression of cGAS-STING, TBK1, IKKβ. Downstream of the IFN-β signaling, MGF360-12L blocks the ISRE promoter activation by reducing total protein level of IRF9. Moreover, MGF360-12L protein can inhibit IFN-β-mediated antiviral effects. In conclusion, our findings suggest that MGF360-12L is a multifunctional immune-evasion protein that inhibits both the expression and effect of IFN-β, which could partially explain the attenuation of relevant gene-deleted ASFV strains, and shed light on the development of efficient ASFV live attenuated vaccines in the future.
Źródło:
Polish Journal of Veterinary Sciences; 2023, 26, 1; 119-130
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of Polymeric Binders on the RDX-based Explosive Response Character under Slow Cook-off Conditions
Autorzy:
Yan, X.
Li, X. D.
Zhang, Y. R.
Liu, L.
Zhang, X. M.
Tan, Y. X.
Wang, H.
Wang, X. Q.
Powiązania:
https://bibliotekanauki.pl/articles/358419.pdf
Data publikacji:
2018
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
RDX-based explosive
slow cook-off experiment
binder content
binder type
Opis:
Due to safety requirements, insensitive behaviour under slow thermal heating (cook-off) conditions is a desirable behaviour for today’s munitions. In this paper a cook-off device is designed to test two groups of RDX-based PBX explosives. In the first group the binder type was varied and in the second group the binder content of the RDX-based explosive was changed. Eleven samples were examined in order to evaluate the influence of four different binders and seven different binder contents on the shell deformation and the degree of the involved reaction. The test results showed that the degree of the reaction can be improved by changing the binder content, but not by the binder type. This phenomenon was explained by the thermal-conduction theory.
Źródło:
Central European Journal of Energetic Materials; 2018, 15, 2; 339-350
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Internal Friction of Li7La3Zr2O12 Based Lithium Ionic Conductors
Autorzy:
Wang, X. P.
Song, L.
Hu, J.
Xia, Y. P.
Xia, Y.
Gao, Y. X.
Zhang, L. C.
Magalas, L. B.
Fang, Q. F.
Powiązania:
https://bibliotekanauki.pl/articles/958222.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
lithium ionic conductor
Li7La3Zr2O12
internal friction
Opis:
The diffusion mechanisms of lithium ions in tetragonal phase as well as in Al and Nb stabilized cubic Li7La3Zr2O12 compounds were investigated by low-frequency internal friction technique. In the cubic Li7La3Zr2O12 phase, a remarkable relaxation-type internal friction peak PC with a peak height up to 0.12 was observed in the temperature range from 15°C to 60°C. In the tetragonal phase however, the height of the PT peak dropped to 0.01. The obvious difference of the relaxation strength between the cubic and tetragonal phases is due to the different distribution of lithium ions in lattice, ordered in the tetragonal phase and disordered in the cubic phase. Based on the crystalline structure of the cubic garnet-type Li7La3Zr2O12 compound, it is suggested that the high internal friction peak in the cubic phase may be attributed to two diffusion processes of lithium ions: 96h↔96h and 96h↔24d.
Źródło:
Archives of Metallurgy and Materials; 2016, 61, 1; 21-24
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Identification, evaluation, and application of the genomic-SSR loci in ramie
Autorzy:
Luan, M.-B.
Yang, Z.-M.
Zhu, J.-J.
Deng, X.
Liu, C.-C.
Wang, X.-F.
Xu, Y.
Sun, Z.-M.
Chen, J.-H.
Powiązania:
https://bibliotekanauki.pl/articles/57981.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Botaniczne
Opis:
To provide a theoretical and practical foundation for ramie genetic analysis, simple sequence repeats (SSRs) were identified in the ramie genome and employed in this study. From the 115 369 sequences of a specific-locus amplified fragment library, a type of reduced representation library obtained by high-throughput sequencing, we identified 4774 sequences containing 5064 SSR motifs. SSRs of ramie included repeat motifs with lengths of 1 to 6 nucleotides, and the abundance of each motif type varied greatly. We found that mononucleotide, dinucleotide, and trinucleotide repeat motifs were the most prevalent (95.91%). A total of 98 distinct motif types were detected in the genomic-SSRs of ramie. Of them, The A/T mononucleotide motif was the most abundant, accounting for 41.45% of motifs, followed by AT/TA, accounting for 20.30%. The number of alleles per locus in 31 polymorphic microsatellite loci ranged from 2 to 7, and observed and expected heterozygosities ranged from 0.04 to 1.00 and 0.04 to 0.83, respectively. Furthermore, molecular identity cards (IDs) of the germplasms were constructed employing the ID Analysis 3.0 software. In the current study, the 26 germplasms of ramie can be distinguished by a combination of five SSR primers including Ibg5-5, Ibg3-210, Ibg1-11, Ibg6-468, and Ibg6-481. The allele polymorphisms produced by all SSR primers were used to analyze genetic relationships among the germplasms. The similarity coefficients ranged from 0.41 to 0.88. We found that these 26 germplasms were clustered into five categories using UPGMA, with poor correlation between germplasm and geographical distribution. Our study is the first large-scale SSR identification from ramie genomic sequences. We have further studied the SSR distribution pattern in the ramie genome, and proposed that it is possible to develop SSR loci from genomic data for population genetics studies, linkage mapping, quantitative trait locus mapping, cultivar fingerprinting, and as genetic diversity studies.
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:
3D Simulation of Warp Knitted Structures with a New Algorithm Based on NURBS
Symulacja 3D struktur dzianych z zastosowaniem algorytmu opartego na algorytmie NURBS
Autorzy:
Xu, H Y
Chen, N L
Jiang, J H
Jin, L X
Wang, Z X
Powiązania:
https://bibliotekanauki.pl/articles/232913.pdf
Data publikacji:
2015
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
warp knitted stitch
three-dimensional simulation
NURBS
joint of stitches
MATLAB
ścieg osnowy tkaniny
struktura dzianin
symulacja trójwymiarowy
algorytm NURBS
wspólne szwów
oprogramowanie Matlab
Opis:
In order to obtain a three-dimensional computer simulation of warp knitted structures with more flexibility and realism, a new algorithm using Matlab was developed by NURBS based on empirical geometrical loop models. With the principles of NURBS curves, once the values of data points are known, the control points with two coincidence points at the start and end points can be uncomplicatedly calculated by Matlab. Then the NURBS curve of a single typical stitch can be simulated flexibly by Matlab. A new typical stitch selected from two stitches simulated directly by the new method is redefined to improve the joint of neighboring stitches, and it is found that there are two types of redefined typical warp knitted stitches judged by whether the two under lap on the same side or not. Based on the redefined typical warp knitted stitch, two warp knitted structures are simulated regardless of the loop offset, and all the joints of stitches are smooth.
Przeprowadzono symulację komputerową struktur dzianin w wymiarze 3D, opracowując w tym celu nową procedurę opartą na algorytmie NURBS. Do tego celu wykorzystano oprogramowanie MATLAB. Symulację 3D przeprowadzono w oparciu o procedury numeryczne umożliwiające wykreślenie przestrzennych figur geometrycznych opisujących strukturę dzianin. Symulowano kształt oczek zamkniętych i otwartych podstawowych splotów kolumienkowych trykotu, sukna i aksamitu. W oparciu o 8 punktów referencyjnych zorientowano konfigurację pętli oczka i łącznika w postaci przestrzennej linii eliptycznej. Do zapisu struktury splotu kształtu oczek wykorzystywano aparat matematyczny w postaci macierzy.
Źródło:
Fibres & Textiles in Eastern Europe; 2015, 1 (109); 57-60
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
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:
Software Startups – A Research Agenda
Autorzy:
Unterkalmsteiner, M.
Abrahamsson, P.
Wang, X. F.
Nguyen-Duc, A.
Shah, S.
Bajwa, S. S.
Baltes, G. H.
Conboy, K.
Cullina, E.
Dennehy, D.
Edison, H.
Fernandez-Sanchez, C
Garbajosa, J.
Gorschek, T.
Klotins, E.
Hokkanen, L.
Kon, F.
Lunesu, I.
Marchesi, M.
Morgan, L.
Oivo, M.
Selig, C.
Seppänen, P.
Sweetman, R.
Tyrväinen, P.
Ungerer, C.
Yagüe, A.
Powiązania:
https://bibliotekanauki.pl/articles/953060.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
software startup
research agenda
software-intensive systems
Opis:
Software startup companies develop innovative, software-intensive products within limited time frames and with few resources, searching for sustainable and scalable business models. Software startups are quite distinct from traditional mature software companies, but also from micro-, small-, and medium-sized enterprises, introducing new challenges relevant for software engineering research. This paper’s research agenda focuses on software engineering in startups, identifying, in particular, 70+ research questions in the areas of supporting startup engineering activities, startup evolution models and patterns, ecosystems and innovation hubs, human aspects in software startups, applying startup concepts in non-startup environments, and methodologies and theories for startup research. We connect and motivate this research agenda with past studies in software startup research, while pointing out possible future directions. While all authors of this research agenda have their main background in Software Engineering or Computer Science, their interestin software startups broadens the perspective to the challenges, but also to the opportunities that emerge from multi-disciplinary research. Our audience is therefore primarily software engineering researchers, even though we aim at stimulating collaborations and research that crosses disciplinary boundaries. We believe that with this research agenda we cover a wide spectrum of the software startup industry current needs.
Źródło:
e-Informatica Software Engineering Journal; 2016, 10, 1; 89-123
1897-7979
Pojawia się w:
e-Informatica Software Engineering Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation and Properties of RDX-Nitrocellulose Microspheres
Autorzy:
Shi, X.
Wang, J
Li, X.
Powiązania:
https://bibliotekanauki.pl/articles/358363.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
RDX
nitrocellulose
flash vaporization process
thermal stability
Opis:
A new insensitive explosive based on RDX and with Nitrocellulose (NC) as binder has been prepared using a flash vaporization process. Scanning electron microscopy was used to characterize the morphology and particle size of the resulting RDX-NC microspheres. X-ray photoelectron spectroscopy, Differential Scanning Calorimetry, impact sensitivity, vacuum stability and burning rate of raw RDX, RDX-NC and RDX-1 were also used to characterize the explosive. The RDX-NC microspheres were found to have a fibrous surface. The microspheres ranged in size from 0.5 μm to 4 μm. The NC formed a coat on the surface of the RDX. The activation energies of raw RDX, RDX-1 and RDX-NC were found to be 200.8 kJ·mol−1, 183.9 kJ·mol−1 and 187.2 kJ·mol−1, respectively. The drop heights of raw RDX, RDX-1 and RDX-NC were found to be 21.3 cm, 51.7 cm and 82.9 cm, respectively. The friction sensitivity of RDX-NC was lower than that of raw RDX and RDX-1. In the vacuum stability test, the volumes of evolved gas from raw RDX, RDX-1 and RDX-NC were 0.12 mL·g−1, 0.12 mL·g−1, and 0.09 mL·g−1, respectively. The burning rates of RDX-NC-based propellants were higher than that of RDX-1 and raw RDX based propellants at 5-15 MPa. The burning rate pressure exponent of RDX-NC based propellants is 0.9929 at 40-200 MPa.
Źródło:
Central European Journal of Energetic Materials; 2016, 13, 4; 871-881
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A class of nonlocal integrodifferential equations via fractional derivative and its mild solutions
Autorzy:
Wang, J.
Yan, X.
Zhang, X. H.
Wang, T. M
Li, X. Z.
Powiązania:
https://bibliotekanauki.pl/articles/255673.pdf
Data publikacji:
2011
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
integrodifferential equations
fractional derivative
nonlocal conditions
resolvent operator and their norm continuity
fixed point theorem
mild solutions
Opis:
In this paper, we discuss a class of integrodifferential equations with nonlocal conditions via a fractional derivative of the type: [formula]. Some sufficient conditions for the existence of mild solutions for the above system are given. The main tools are the resolvent operators and fixed point theorems due to Banach's fixed point theorem, Krasnoselskii's fixed point theorem and Schaefer's fixed point theorem. At last, an example is given for demonstration.
Źródło:
Opuscula Mathematica; 2011, 31, 1; 119-135
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of surfactants on the flotation performance of low-rank coal by particle sliding process measurements
Wpływ surfaktantów na sprawność flotacji węgla niskiej jakości w pomiarach procesu przemieszczania się cząstek
Autorzy:
Wang, S.
Tao, X.
Powiązania:
https://bibliotekanauki.pl/articles/216970.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Instytut Gospodarki Surowcami Mineralnymi i Energią PAN
Tematy:
węgiel o niskiej wartości
prędkość kątowa poślizgu
hydrofobowość
środek powierzchniowo czynny
wynik XPS
low rank coal
slip angle velocity
hydrophobicity
surfactant
XPS result
Opis:
In this paper, flotation performances of low-rank coal were investigated in the 2-ethyl hexanol, DAH (dodecyl amine hydrochloride), and SDS (sodium dodecyl sulfate) solutions, respectively. In order to reduce the heterogeneity and hydrodynamic effects on the hydrophobicity and movement trajectory of low-rank coal particles, respectively, experimental coal samples with low ash content and 0.500–0.250 mm in size fraction were adopted. The XPS result demonstrated that the total silicium and aluminum content of 0.500–0.250 mm size fraction was 1.58%. It was also found that the ash content of the 0.500–0.250 mm size fraction was 1.91%. Therefore, it demonstrated that there were few hydrophilic mineral particles on the coal sample surface. Thus, the heterogeneity effect of hydrophilic mineral particles during sliding process measurements can be ignored. The XPS result also indicated that after the grinding process, the mineral content on the low-rank coal surface was very small, which would play a small role in the hydrophobicity of low-rank coal samples. The flotation results indicated that the hydrophobicity of the low-rank coal particles could be improved by nonionic 2-ethyl hexanol and cation DAH surfactants. Moreover, from the analysis of slip angle velocity, it demonstrated that the flotation responses of low-rank coal were depressed by anionic SDS. Furthermore, it was observed that the slip angle velocity can be used to evaluate the effect of surfactant agents on the flotation performance of low-rank coal while the surfactant concentration was more than 10–6 mol/L.
W niniejszym artykule zbadano właściwości flotacyjne węgla niskiej jakości w roztworach 2-etyloheksanolu, DAH (chlorowodorku dodecylu) i SDS (dodecylosiarczanu sodu). W celu zmniejszenia niejednorodności i skutków hydrodynamicznych hydrofobowości i trajektorii ruchu cząstek węgla niskiej jakości przyjęto do doświadczeń próbki węgla o niskiej zawartości popiołu z klasy ziarnowej 0,500–0,250 mm. Wynik XPS wykazał, że całkowita zawartość krzemu i glinu w klasie ziarnowej 0,500–0,250 mm wynosiła 1,58%. Stwierdzono również, że zawartość popiołu w klasie ziarnowej 0,500–0,250 mm wynosiła 1,91%. W związku z tym wykazano, że na powierzchni próbki węgla znajduje się niewiele hydrofilowych cząstek mineralnych. W ten sposób można pominąć efekt heterogeniczności hydrofilowych cząstek mineralnych podczas pomiarów kąta poślizgu. Wynik XPS wskazał również, że po procesie mielenia zawartość minerałów na powierzchni węgla niskiej jakości była bardzo mała, dlatego też występuje słabe oddziaływanie na hydrofobowość tych próbek. Wyniki flotacji wskazują, że hydrofobowość cząstek węgla niskiej jakości można poprawić za pomocą niejonowego 2-etyloheksanolu i kationowych środków powierzchniowo czynnych DAH. Analiza prędkości kąta poślizgu wykazuje, że flotacja węgla niskiej jakości została obniżona przez SDS. Ponadto zaobserwowano, że prędkość kąta poślizgu może być wykorzystana do oceny wpływu środków powierzchniowo czynnych na sprawność flotacji węgla niskiej jakości, gdy ich stężenie jest większe niż 10–6 mol/L.
Źródło:
Gospodarka Surowcami Mineralnymi; 2018, 34, 1; 69-82
0860-0953
Pojawia się w:
Gospodarka Surowcami Mineralnymi
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Consistency analysis of degradation mechanism in step-stress acc elerated degradation testing
Analiza niezmienności mechanizmu degradacji w przyspieszonych badaniach degradacji z obciążeniem stopniowym
Autorzy:
Lu, X.
Chen, X.
Wang, Y.
Tan, Y.
Powiązania:
https://bibliotekanauki.pl/articles/301224.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
przyspieszone badania degradacji z obciążeniem stopniowym
niezmienność mechanizmu degradacji
test ilorazu wiarygodności
uszczelka gumowa
step-stress accelerated degradation testing
degradation mechanism consistency
likelihood ratio test
rubber seals
Opis:
Step-stress accelerated degradation testing (SSADT) has been used by many researchers for the reliability assessment of highly reliable products. Most of the previous works on SSADT assume that the degradation mechanism keeps unchanged during the accelerated degradation testing. However, some recent investigations have shown that degradation mechanisms may be different among various accelerated stress levels. For an accurate extrapolation of accelerated testing results to the ambient condition, the degradation mechanism at all accelerated stress levels should be the same. Taking the variation of the degradation mechanism into account, it is advisable to test the degradation mechanism consistency in a SSADT. This paper proposes a likelihood ratio test method for the consistency analysis of degradation mechanism in the SSADT. We first introduce the basic principle of the likelihood ratio test method. Then we describe the model for SSADT data and the parameter estimation method. Further, we propose a decision rule for the consistency analysis. The proposed method is illustrated and validated with examples on the consistency analysis of degradation mechanism in a SSADT of silicone rubbers.
Wielu badaczy wykorzystuje przyspieszone badania degradacji z obciążeniem stopniowym (ang. step-stress accelerated degradation testing, SSADT) do oceny niezawodności wysoce niezawodnych produktów. Większość wcześniejszych prac nad SSADT zakłada, że podczas badań przyspieszonych mechanizm degradacji pozostaje niezmienny. Jednak, najnowsze badania wykazały, że mechanizmy degradacji mogą różnić się w zależności od poziomu przyspieszonego obciążenia. Poprawna ekstrapolacja wyników badań przyspieszonych na warunki otoczenia wymaga aby mechanizm degradacji przy wszystkich poziomach obciążenia był taki sam. Biorąc pod uwagę zmienność mechanizmu degradacji, wskazane jest badanie stopnia (nie)zmienności mechanizmu degradacji w badaniach SSADT. W artykule zaproponowano metodę analizy niezmienności mechanizmu degradacji w badaniach SSADT opartą na teście ilorazu wiarygodności. W pierwszej kolejności, przedstawiono podstawową zasadę testu ilorazu wiarygodności. Następnie, opisano model dla danych SSADT i metodę estymacji parametrów. Ponadto zaproponowano regułę decyzyjną stanowiąca narzędzie do analizy niezmienności. Omawianą metodę zilustrowano i zweryfikowano na przykładzie analizy niezmienności mechanizmu degradacji w badaniach SSADT gumy silikonowej.
Źródło:
Eksploatacja i Niezawodność; 2017, 19, 2; 302-309
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Phase Stability of Ammonium Nitrate with Organic Potassium Salts
Autorzy:
Xu, Z.-X.
Fu, X.-Q.
Wang, Q.
Powiązania:
https://bibliotekanauki.pl/articles/358264.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
ammonium nitrate(V)
phase transition
organic compounds
differential scanning calorimetry
Opis:
A study has been undertaken on the effect of additives on the phase transition of ammonium nitrate(V) (AN). Results obtained using Differential Scanning Calorimetry (DSC) showed that organic compounds and potassium salts of organic compounds have an effect on the phase transition behavior of AN. The samples were further analyzed using infrared (IR) and powder X-ray diffraction (XRD). The mechanism of phase stabilization of AN by compounds of this kind was examined. The present study showed that the influence of additives on the phase transition of AN occurs through the polar groups that are involved in intermolecular interactions of orbital and electrostatic types that form new hydrogen bonds. AN exists in only one phase in the temperature range from 30 °C to +100 °C, when a potassium salt of organic compounds was added. However, with organic compounds, the III→II phase transition was changed. IR and XRD of composites are characterized by new intermolecular interactions. Compacted samples of AN containing potassium salts of organic compounds exhibited better stability than AN containing organic compounds to multiple cyclic changes within a temperature range. This we named ‘freezing and thawing analysis’. Additives have two functions on the AN phase transition. First, solid solutions of AN mixture were formed for K+ replacement of NH4+. Second, hydrogen bonds formed, which caused AN and salts of organic compounds to interact intimately.
Źródło:
Central European Journal of Energetic Materials; 2016, 13, 3; 736-754
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Antimicrobial properties of flax fibers in the enzyme retting process
Właściwości antybakteryjne lnu w procesie enzymatycznego roszenia
Autorzy:
Tian, Y.
Liu, X.
Zheng, X.
Wang, L.
Powiązania:
https://bibliotekanauki.pl/articles/231965.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
flax fibre
pectic substance content
antibacterial property
retting
włókno lniane
substancja pektynowa
właściwości antybakteryjne
roszenie
Opis:
“GB/T 20944.3-2008--Part 3: Shake flask method” was applied to assess the antimicrobial property of flax fibres. The antimicrobial efficiency of flax fibre was represented as the absolute antimicrobial rate and relative antimicrobial rate. Cotton fibre served as a contrast in relation to the antimicrobial rate. The retted flax fibre showed an absolute antimicrobial rate against E.coli and S. aureus, but only presented a relative antimicrobial rate against S. cerevisiae. The contents of pectic substances of flax straw such as cerolipoid, hydrotrope, pectin, hemicellulose and lignin declined during flax retting, especially lignin, whose content declined from 24% to 7.13%, and gaps appeared between the fibre bundles. Consequently the antimicrobial efficiency of flax fibre decreased gradually. This experiment confirmed the existence of antibacterial substances, but exactly what compounds associated with flax exhibiting antimicrobial properties is not discussed.
Właściwości antybakteryjne włókien lnianych badano zgodnie z normą GB/T20944.32008: Właściwości oceniano poprzez bezwzględną i względną antybakteryjną intensywność. Włókna bawełniane służyły jako materiał porównawczy przy ocenianiu antybakteryjnej intensywności względnej. Roszone włókna lnu wykazywały bezwzględną intensywność antybakteryjną przeciwko E. coli i S. aureus, ale tylko względną intensywność antybakteryjną przeciwko S. cerevisiae. Zawartość substancji pektynowych w słomie lnianej, takich jak cerolipoidy, hydrotopy, pektyny, chemiceluloza, i ligniny zmniejszała się podczas roszenia. Szczególnie zmniejszyła się zawartość lignin spadając z 24% do 7,13%. W czasie roszenia pojawiały się szczeliny pomiędzy wiązkami włókien. W konsekwencji zdolności antybakteryjne włókien lnianych ulegały systematycznej degradacji. Przeprowadzony eksperyment potwierdził istnienie antybakteryjnych substancji ale nie stwierdzono, które składniki były najbardziej aktywne antybakteryjnie.
Źródło:
Fibres & Textiles in Eastern Europe; 2016, 1 (115); 15-17
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Antibiotics in WWTP discharge into the Chaobai River, Beijing
Autorzy:
Zhang, C.
Wang, L.
Gao, X.
He, X.
Powiązania:
https://bibliotekanauki.pl/articles/204951.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
antibiotics
PPCPs
pharmaceuticals and personal care products
WWTP
wastewater treatment plant
BAF
biological aerated filter
advanced treatment
Opis:
22 representative antibiotics, including 8 quinolones (QNs), 9 sulfonamides (SAs), and 5 macrolides (MCs) were selected to investigate their occurrence and removal efficiencies in a Wastewater Treatment Plant (WWTP) and their distribution in the receiving water of the Chaobai River in Beijing, China. Water quality monitoring was performed in an integrated way at different selected points in the WWTP to explore the potential mechanism of antibiotics removal during wastewater treatment. Water quality of the Chaobai River wa s also analyzed to examine environmental distribution in a river ecosystem. The results showed that within all the 22 compounds examined, 10 antibiotics were quantifi ed in wastewater influent, 10 in effluent, and 7 in river. Sulfadiazine (SDZ, 396 ng/L) and Sulfamethazine (SMZ, 382 ng/L) were the dominating antibiotics in the influent. Both the conventional treatment and advanced Biological Aerated Filter (BAF) system was important for the removal of antibiotics from the wastewater. And the concentrations of selected antibiotics were ranged from 0–41.8 ng/L in the effluent-receiving river. Despite the fact that the concentrations were reduced more than 50% compared to effluent concentrations, WWTP discharge was still regarded as a dominant point-source input of antibiotics into the Chaobai River.
Źródło:
Archives of Environmental Protection; 2016, 42, 4; 48-57
2083-4772
2083-4810
Pojawia się w:
Archives of Environmental Protection
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:
Research on Knitted Fabric Properties of Yak Cashmere and Cotton Blend Yarns
Badania właściwości dzianin wykonanych z przędz kaszmirowo-bawełnianych.
Autorzy:
Qin, X.
Liang, H.
Wang, G.
Su, X.
Liu, X.
Powiązania:
https://bibliotekanauki.pl/articles/234186.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
yak cashmere
blend yarn
knitted fabric
blend ratio
kaszmir
przędza mieszana
trykot
właściwości dzianiny
Opis:
As a natural fibre, yak cashmere has attracted more and more attentions in textile processing due to its excellent properties, environmentally friendly characteristics and inexpensive prices. However, the direct processing of yak cashmere, especially pure yarn spinning, is difficult since the dispersion of the fibre length is large. Therefore, in this paper, yak cashmere and cotton blend yarns were spun. Compact Sirospun yarns with three different kinds of blending ratios; 70/30, 50/50 and 30/70, were spun, and corresponding spun yarn qualities: hairiness, breaking strength and evenness were tested. It is shown that with an increasing content of cotton, for the same yarn count spun, all properties tested were improved. Then the properties of corresponding knitted fabric, including the permeability, thickness, static voltage, warmth retention, whiteness, water permeability, bursting strength, elastic recovery, tensile properties, drape, wear resistance, pilling, anti-ultraviolet resistance and bending stiffness were measured and comparatively analysed. It is shown that with an increasing content of yak cashmere, the fabric is lighter and thinner, and the air permeability, warmth retention, wear resistance and pilling were all improved, while the strength and elongation properties as well as water permeability were worsened. Meanwhile the average weight distribution of yak cashmere and cotton in the yarn is beneficial for the fabric elastic recovery property and drape.
Jako włókno naturalne, kaszmir przyciąga coraz więcej uwagi w przemyśle tekstylnym dzięki doskonałym właściwościom, przyjaznym dla środowiska cechom i niewysokim cenom. Jednakże bezpośrednie przetworzenie kaszmiru jakowego, a zwłaszcza przędzenia przędzy, jest trudne, ze względu na duży rozrzut długości włókien. Z tego powodu w przedstawionej pracy wytworzono przędze bawełniano-kaszmirowe o trzech różnych proporcjach: 70/30, 50/50 i 30/70. Wykazano, że wraz ze wzrastającą zawartością bawełny, badane właściwości tj. włochatość, wytrzymałość na rozerwanie i równomierność uległy polepszeniu. Zbadano także właściwości otrzymanych dzianin tj. przepuszczalność powietrza, grubość, napięcie statyczne, ciepłochronność, stopień bieli, przepuszczalność wody, wytrzymałość na rozerwanie, odprężenie, właściwości mechaniczne podczas rozciągania, układalność, odporność na ścieranie, pilling, oporność na promieniowanie ultrafioletowe i sztywność zginania. Wykazano, że wraz z rosnącą zawartością kaszmiru dzianiny są lżejsze i cieńsze, a przepuszczalność powietrza, ciepłochronność, odporność na ścieranie uległy poprawie, natomiast właściwości wytrzymałościowe i przepuszczalność wody uległy pogorszeniu.
Źródło:
Fibres & Textiles in Eastern Europe; 2017, 4 (124); 31-35
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation and Characterization of HMX/Estane Nanocomposites
Autorzy:
Shi, X.
Wang, J.
Li, X.
An, Ch.
Powiązania:
https://bibliotekanauki.pl/articles/358274.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
HMX
Estane 5703
spray drying
nanocomposites
thermal stability
Opis:
A new insensitive explosive based on octahydro-1,3,5,7-tetranitro1,3,5,7-tetrazocine (HMX) was prepared by spray drying using Estane 5703 as a binder. Scanning electron microscopy was used to characterize the morphology and particle size of the HMX/Estane 5703 nanocomposites. The composites were analyzed by X-ray diffractometry and differential scanning calorimetry and their impact sensitivity was determined. For comparison, raw HMX was also tested using these three methods. The nanocomposite morphology was found to be microspherical (1 to 8 μm diameter) and composed of many tiny particles, 30 to 150 nm in size. The crystal type of the HMX/Estane 5703 nanocomposites was unchanged. The activation energy, self-ignition temperature and average drop height of the raw HMX were 515.66 kJ·mol-1, 278.63 °C and 18.4 cm, respectively. In comparison, the corresponding values for the HMX/Estane 5703 nanocomposites were 488.92 kJ·mol-1, 279.3 °C and 75.4 cm, respectively.
Źródło:
Central European Journal of Energetic Materials; 2014, 11, 3; 433-442
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
High-efficiency carrier frequency estimation algorithm for real-time multi-domain communication signal analysis
Autorzy:
Wang, Q.
Yang, X.
Yan, X
Qin, K.
Powiązania:
https://bibliotekanauki.pl/articles/221239.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
carrier frequency estimation
multi-domain communication
signal analysis
Opis:
Based on real-time multi-domain communication signal analysis architecture, a high-efficiency blind carrier frequency estimation algorithm using the power spectrum symmetry of the measured modulated signal is presented. The proposed algorithm, which utilizes the moving averaged power spectrum achieved by the realtime spectrum analysis, iteratively identifies the carrier frequency in according to the power difference between the upper sideband and lower sideband, which is defined and revised by the estimated carrier frequency in each iteration. When the power difference of the two sidebands converges to the preset threshold, the carrier frequency can be obtained. For the modulation analysis, the measured signal can be coarsely compensated by the estimated result, and the residual carrier frequency error is eliminated by a following carrier synchronization loop. Compared with previous works, owing to the moving averaged power spectrum normalization and the smart iterative step variation mechanism for the two sidebands definition, the carrier frequency estimation accuracy and speed can be significantly improved without increasing the computational effort. Experimental results are included to demonstrate the outstanding performance of the proposed algorithm.
Źródło:
Metrology and Measurement Systems; 2014, 21, 2; 281-292
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dynamic electric vehicles charging load allocation strategy for residential area
Autorzy:
Wang, Y.
Ma, X.
Wang, F.
Hou, X.
Sun, H.
Zheng, K.
Powiązania:
https://bibliotekanauki.pl/articles/140939.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
electric vehicles
charging power management
allocation strategy
priority assessment
Opis:
A large amount of electric vehicles (EVs) charging load will bring significant impact to the power system. An appropriate resource allocation strategy is required for securing the power system safety and satisfying EVs charging demand. This paper proposed a power coordination allocation strategy of EVs’ in distribution systems. The strategy divides the allocation into two stages. The first stage is based on scores assigned to EVs through an entropy method, whereas the second stage allocates energy according to EV’s state of charge. The charging power is delivered in order to maximize EV users’ satisfaction and fairness without violation of grid constraints. Simulation on a typical power-limited residential distribution network proves the effectiveness of the strategy. The analysis results indicate that compared with traditional methods, EVs, which have higher charging requirement and shorter available time will get more energy delivered than others. The root-mean-square-error (RMSE) and standard-deviation (SD) results prove the effectiveness of the methodology for improving the balance of power delivery.
Źródło:
Archives of Electrical Engineering; 2018, 67, 3; 641--654
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Oxidation of a lignin model compound of benzyl-ether type linkage in water with H2O2 under an oxygen atmosphere catalyzed by Co(Salen)
Utlenianie modelowego związku ligniny z typem wiązania benzylowo-eterowego w wodzie z H2O2 w atmosferze tlenu katalizowane Co(Salen)
Autorzy:
Zhou, X.F.
Qin, J.X.
Wang, S.R.
Powiązania:
https://bibliotekanauki.pl/articles/52363.pdf
Data publikacji:
2011
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technologii Drewna
Tematy:
oxidation
lignin model compound
benzyl-ether type
linkage
water
oxygen atmosphere
cobalt salen complex
catalytic property
analytical technique
veratrylglycerol-beta-guaiacyl-alpha,gamma-dimethylether
Opis:
The catalytic properties of Cobalt salen? complex in the oxidation of a lignin model compound [veratrylglycerol-β-guaiacyl-α,γ-dimethylether, VGD] have been investigated in order to obtain the mechanistic aspects of the reaction between Co(salen) and VGD under an oxygen atmosphere using hydrogen peroxide as an oxidant. VGD was found to undergo structural changes in response to the catalytic reaction as characterised by different analytical techniques (FT-IR, H-1 NMR and GC-MS), yielding 2-methoxy phenol and biphenyl. A mechanism for the oxidation of VGD was postulated.
Zbadano katalityczne właściwości kompleksu Co(Salen) w utlenianiu modelowego związku ligniny (veratrylglycerol-β-guaiacyl-α,γ-dimetyleter, VGD) w celu określenia mechanicznych aspektów reakcji pomiędzy Co(salen) i VGD w atmosferze tlenu przy zastosowaniu nadtlenku wodoru jako utleniacza. Zaobserwowano, że w VGD zaszły zmiany strukturalne w odpowiedzi na reakcję katalityczną, co przedstawiono za pomocą różnych technik analitycznych (FTIR, H-1 NMR oraz GC-MS). W efekcie otrzymano 2-metoksy fenol i bifenyl.
Źródło:
Drewno. Prace Naukowe. Doniesienia. Komunikaty; 2011, 54, 186
1644-3985
Pojawia się w:
Drewno. Prace Naukowe. Doniesienia. Komunikaty
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation and Performance of a Novel Water Gel Explosive Containing Expired Propellant Grains
Autorzy:
Wang, P.
Xei, X.
He, W.
Powiązania:
https://bibliotekanauki.pl/articles/358510.pdf
Data publikacji:
2013
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
expired propellant
detonation performance
reuse
water gel explosive
Opis:
Novel water gel explosives containing expired single base and double base propellant grains were prepared by using a new gelling agent and a simple process. The shock wave overpressures and underwater output energies of the explosives were measured. The detonation performances of the explosives were also investigated. As the particle size of the propellant was increased, the detonation velocity, peak overpressure and underwater energy of the explosive containing single base propellant (NCP) were gradually reduced. Double base propellant (DBP) had low detonation sensitivity due to its thermoplasticity. When it was mixed with the appropriate quantity of NCP, DBP could also be reused. NCP acted as the sensitizer and energy source in the explosive containing both DBP and NCP. So the detonation velocity, peak overpressure and underwater energy of the explosive increased with the increase in ωNCP. With excellent detonation performance, these two kinds of water gel explosives can be used as opencast blasting agents.
Źródło:
Central European Journal of Energetic Materials; 2013, 10, 4; 495-507
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Coupling mechanism and coupling degree measurement model of shipbuilding industry cluster
Autorzy:
Su, Y.
Wang, F.
An, X.
Powiązania:
https://bibliotekanauki.pl/articles/258740.pdf
Data publikacji:
2016
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
coupling mechanism
coupling degree measurement model
shipbuilding industry cluster
Opis:
This article was aimed to analyse the working condition of the coupling mechanism in Chinese shipbuilding industry cluster. Literature review was conducted to unveil the coupling mechanism of shipbuilding industry cluster, providing analysis of the present development of shipbuilding industry. A theoretical model was proposed by using the efficacy function and the capacity of the coupling coefficient while measuring the coupling of the shipbuilding industry cluster. Four coupling characteristics were found including relevant, systemic, diversity, and collaborative in the shipbuilding industry cluster. The shipbuilding industry cluster has two levels of coupling mechanism including the core layer coupling mechanism and the support layer coupling mechanism respectively. The improvement through coupling the core layer, support layer, and the coupling between two levels, is an effective way to achieve long-term stable development in Chinese shipbuilding industry cluster.
Źródło:
Polish Maritime Research; 2016, S 1; 78-85
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessing the accuracy of SRTM DEM and ASTER GDEM datasets for the coastal zone of shandong province, Eastern China
Autorzy:
Luan, S.
Hou, X.
Wang, Y.
Powiązania:
https://bibliotekanauki.pl/articles/258952.pdf
Data publikacji:
2015
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
elevation errors
SRTM DEM
ASTER DEM
Opis:
This study assessed the performance of recently released 3 arc second SRTM DEM version 4.1 by CSI-CGIAR and 1 arc second ASTER GDEM version 1 and version 2 by METI-NASA in comparison with ground control points from 1:50000 digital line graphs for the coastal zone of Shandong Province, Easter China. The vertical accuracy of SRTM DEM is 13.74 m root mean square error (RMSE), and GDEM version 1 reaches 24.11 m RMSE. Version 2 of ASTER GDEM shows better performance than version 1 and SRTM DEM with a RMSE of 12.12 m. A strong correlation of the magnitude of elevation error with slope and elevation is identified, with lager error magnitudes in the steeper slopes and higher elevations. Taking into account slope and elevation has the potential to considerably improve the accuracy of the SRTM DEM and GDEM version 1 products. However, this improvement for GDEM version 2 can be negligible due to their limited explanatory power for the DEM elevation errors.
Źródło:
Polish Maritime Research; 2015, S 1; 15-20
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pseudo-static experiment and analysis on seismic behavior of the RC columns strengthened by GHPFRCC
Autorzy:
Li, X.
Wang, J.
Luo, M.
Powiązania:
https://bibliotekanauki.pl/articles/259179.pdf
Data publikacji:
2015
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
green high performance fiber reinforced cementitious composites (GHPFRCC)
pseudo-static test
reinforced concrete column
strengthening
seismic performance
Opis:
Green high performance fiber reinforced cementitious composites (GHPFRCC) are a new class of sustainable cementitious composites, employing a high volume of fly ash to replace cement. In addition to increasing the sustainability of the construction environment, GHPFRCC exhibits a high tensile ductility and multiple cracking behaviors in the strainhardening state. These materials can effectively improve the structural energy dissipation capacity and structural durability. In this study, the optimum mixture ratio of GHPFRCC is presented established using an orthogonal experiment for a specific engineering application. The described GHPFRCC sustains the mechanical performance of concrete and is employed as the outer cladding to strengthen concrete columns. The finite element analysis of the material was based on the software ABAQUS and pseudo static experiments were conducted to exhibit retrofitting of GHPFRCC applied in the rehabilitation of seismic-damaged concrete columns. The computed and experimental results showed that GHPFRCC, while incorporating high volume fly ash, can retain significant multiple cracking behaviors. The energy dissipation capacity of the GHPFRCC reinforced concrete (RC) column is better than the comparable unreinforced column.
Źródło:
Polish Maritime Research; 2015, S 1; 56-60
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Elastic-plastic analysis for circumferential through crack at boundary of semi’s brace under beam wave
Autorzy:
Wang, F.
Deng, X.
Li, Y.
Powiązania:
https://bibliotekanauki.pl/articles/260258.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
theoretical model
crack damaged brace
semi-submersible platform
beam wave
Opis:
In order to ensure the safety and reliability of the horizontal brace of semi-submersible platform (SEMI) which functions as the supporting structure in SEMI, this article presents an elastic-plastic method to analyze the variations of the crack tip opening displacement, elastic zone and plastic zone of the cracked section of the horizontal brace under beam wave. The brace of the SEMI was assumed to be located a circumferential through crack at its boundary in this article. In addition, the cracked section of the brace has been divided into crack zone, tensile plastic zone, elastic zone and compressive plastic zone in the presented theoretical model. Moreover, the closed form of the solution has been found in this article which is especially suitable solving complicated problems in practical engineering application. Also, a typical new-generation SEMI that is in practical use was selected to analyze the variation tendency of the cracked brace’s parameters using the proposed model which could give good suggestion to semi-submersible platform designers and managers.
Źródło:
Polish Maritime Research; 2018, 4; 106-113
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on marine fhotovoltaic power forecasting based on Wavelet Transform and Echo State Network
Autorzy:
Du, X.
Wang, S.
Zhang, J.
Powiązania:
https://bibliotekanauki.pl/articles/260584.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
marine photovoltaic power system
power forecasting
Wavelet Transform
Echo State Network
Opis:
With the rapid development of photovoltaic power generation technology, photovoltaic power generation system has gradually become an important component of the integrated energy system of marine. High precision short-term photovoltaic power generation forecasting is becoming one of the key technologies in ship energy saving and ship energy efficiency improving. Aiming at the characteristics of marine photovoltaic power generation system, we designed a highprecision power forecasting model (WT+ESN) for marine photovoltaic power generation system with anti-marine environmental interference. In this model, the information mining of the photovoltaic system in marine environment is carried out based on wavelet theory, then the forecasting model basing on echo state network is construct ed. Lastly, three kinds of error metrics are compared with the three traditional models by Matlab, the result shows that the model has high forecasting accuracy and strong robustness to marine environmental factors, which is of great significance to save fuel for ships, improve the energy utilization rate and assist the power dispatching and fuel dispatching of the marine power generation system.
Źródło:
Polish Maritime Research; 2017, S 2; 53-59
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Asymmetry and Contradiction of Mirror Misalignments Influence of Off-Axial Cylindrical Hybrid Resonator
Autorzy:
Wang, N.
Li, X.
Zhu, H.
Powiązania:
https://bibliotekanauki.pl/articles/1399267.pdf
Data publikacji:
2013-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
42.55.Xi
42.60.Da
42.60.Jf
Opis:
The output far-field intensity distributions of off-axial cylindrical hybrid resonator with different mirror misalignments are simulated by coordinate transformation fast Fourier-transform algorithm. The simulations showed that the mirror misalignments influence is different in anticlockwise and clockwise tilt direction. According to the calculation results, the output beam quality of off-axial unstable resonator is analyzed, from the aspects of $M^2$ value and power in the bucket curves. Furthermore, the analysis brings out an interesting contradiction that the beam quality changing evaluated by $M^2$ value is different from that by power in the bucket curves when the mirror misalignments occurred in anticlockwise direction. It demonstrated that the beam quality evaluation of off-axial unstable resonator should not be one-sided.
Źródło:
Acta Physica Polonica A; 2013, 124, 4; 661-664
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On nonlocal problems for fractional differential equations in Banach spaces
Autorzy:
Dong, X.
Wang, J.
Zhou, Y.
Powiązania:
https://bibliotekanauki.pl/articles/255742.pdf
Data publikacji:
2011
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
nonlocal problems
fractional differential equations
existence
generalized singular Gronwall inequality
fixed point method
Opis:
In this paper, we study the existence and uniqueness of solutions to the nonlocal problems for the fractional differential equation in Banach spaces. New sufficient conditions for the existence and uniqueness of solutions are established by means of fractional calculus and fixed point method under some suitable conditions. Two examples are given to illustrate the results.
Źródło:
Opuscula Mathematica; 2011, 31, 3; 341-357
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Computational fluid dynamics (CFD) numerical simulation and particle image velocimetry (PIV) measurement of a packed flotation column
Autorzy:
Yan, X.
Chen, Z.
Wang, L.
Powiązania:
https://bibliotekanauki.pl/articles/110183.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
cyclonic-static microbubble flotation column
computational fluid dynamics
sieve-plate packing
particle image velocimetry
velocity distribution
Opis:
Packing is a useful method to obtain a static separation environment for a high flotation recovery and selectivity. In this study, the single-phase flow field in a packed lab-scale cyclonic-static microbubble flotation column (FCSMC) was investigated by computational fluid dynamics (CFD) simulation. Turbulence model was verified by Particle Image Velocimetry (PIV) experiment; the simulation results obtained by the RSM (Reynolds Stress Model) are closer to the experimental data. Based on this validation, RSM turbulence model was used to obtain the effect of sieve-plate on the hydrodynamic characteristics in the column flotation zone. The results show that the sieve-plate packing arrangement greatly straightens the rotation flow and decreases the turbulence. To further improve the effect of packing, two layers of sieve plates were used, and one diameter (1D = 190 mm) was selected as the reasonable distance between the two layers of sieve plates. To quantitative evaluate the effect of sieve-plate packing, the logarithm of Pdk over the logarithm of Pdo was calculated based on the volume-averaged turbulence dissipation rate, increasing from 24.72 for one layer of sieve-plate packing to 216.96 for two layers of sieve-plate packing. The probability of detachment significantly decreased for two layers of sieve-plate packing, and the recovery efficiency was significantly improved.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 2; 395-405
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Antibiotic resistance and molecular characteristics of Staphylococcus aureus isolated from pigs in Hunan, China
Autorzy:
Zhang, X.
Wang, G.
Yin, C.
Powiązania:
https://bibliotekanauki.pl/articles/2087249.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
antibiotic resistance
molecular characterization
pig-associated S. aureus
Hunan
Źródło:
Polish Journal of Veterinary Sciences; 2020, 23, 4; 563-570
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Life assessment of marine ethylene propylene rubber power cables based on hardness retention rate
Autorzy:
Meng, X.
Wang, Z.
Li, G.
Powiązania:
https://bibliotekanauki.pl/articles/141470.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ethylene propylene rubber (EPR)
nondestructive
hardness retention rate
elongation at break retention rate (EAB %)
termination index
Opis:
The lifetime of ethylene propylene rubber (EPR) insulated cables will decrease because of complex aging processes. From the safety perspective, insulation condition assessment of the cable is essential to maintain an efficient and reliable operation. As a nondestructive and online evaluation method, a hardness retention rate was used to estimate the lifetime of cable. First, accelerated thermal aging tests in the laboratory were performed to measure the elongation at break retention rate (EAB%) and a hardness retention rate at different temperatures. Second, the aging values were processed by the Arrhenius equation and time temperature superposition to assess aging lifetime of insulation at different temperatures and end levels. As the insulation condition assessment of the cable by hardness retention test has no approved standard, the EAB% data were correlated with hardness retention to provide an evaluation basis. The results show that when EAB% picks out the time corresponding to a certain amount of 50% degradation, 10% of hardness retention was chosen as the termination index.
Źródło:
Archives of Electrical Engineering; 2017, 66, 3; 475-484
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biomass partition and carbon storage of Cunninghamia lanceolata chronosequence plantations in Dabie Mountains in East China
Autorzy:
Xie, X.
Cui, J.
Shi, W.
Liu, X.
Tao, X.
Wang, Q.
Xu, X.N.
Powiązania:
https://bibliotekanauki.pl/articles/41359.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
biomass
carbon storage
Cunninghamia lanceolata
Chinese fir
chronosequence
plantation forest
Dabie Mountains
China
Opis:
The quantification of biomass carbon pools is important for understanding carbon cycling in forest ecosystems. This study was designed to reveal the effects of stand age on biomass partitioning and carbon storage of Chinese fir plantation stands in Dabie Mountains of Anhui, East China. A total of six even-aged Chinese fir plantation stands along an age-sequence from 10 to 50 years were selected. To quantify the biomass of different tree components, 18 trees with diameter at breast height (D1.3) from 6.5 to 35.2 cm were harvested from the different aged stands. Biomasses of understory vegetation, forest floor and standing dead trees were also investigated. Total biomass carbon storages ranged from 57.6 to 211.4 Mg ha–1 in the different aged stands. Tree layer comprised from 93.7% to 96.4% of the total biomass C pools in the different aged stands. The C pools of the necromass were from 1.8 to 6.2 Mg ha–1. Stand age had a significant effect on tree biomass partitioning, with an increase in proportion of root biomass. The root/shoot ratios were from 0.187 to 0.312, which was significantly positively correlated to stand age. The existing plantation stands are still developing and have somewhat high rate of biomass and carbon accumulations beyond the normal rotation period (usually 25–30 years) even over an age of 50 years. Appropriate prolongation of the rotation period of Chinese fir plantation will be effective in maintaining long-term productivity and providing large carbon sink. The measurements provide valuable data for modelling productivity of Chinese fir plantation forest.
Źródło:
Dendrobiology; 2016, 76
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study on Ships Safety Control System
Autorzy:
Han, X. J.
Meng, X. Y.
Wang, Z. W.
Powiązania:
https://bibliotekanauki.pl/articles/117442.pdf
Data publikacji:
2009
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
Safety of Navigation
ships safety
Control System
Ships Safety Control System
Ship Accidents
Human Factor
Control Strategy
Accident Precaution
Opis:
The proportion of main reasons of ships accidents to the whole reasons is discussed in the paper. Among these reasons, human factors are in the majority. So a method to prevent wrong orders sent by a navigator is laid emphasis on. On the basis of this, a ships safety control system is studied. The construction and control principle of the ships safety control system, as well as control strategy, implementation method and key technology are elaborated in the paper.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2009, 3, 1; 19-22
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analytical Band Model in Monte Carlo Simulation of Electric Transport in ZnS Thin Film Electroluminescent Devices
Autorzy:
Zhao, H.
Wang, Y.
Xu, X.
Powiązania:
https://bibliotekanauki.pl/articles/2014087.pdf
Data publikacji:
2000-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.60.-b
72.20.-i
Opis:
In this paper, an analytical band model is introduced in Monte Carlo simulation of electric transport process in thin film electroluminescent devices. The band structure of ZnS calculated from the empirical pseudopotential method is fitted by using polynomials. The density of states and scattering rates are also calculated from these polynomials. Based on these results, the electric transport process in ZnS-type thin film electroluminescent devices is simulated through the Monte Carlo method. By comparison with others, this model is as fast as the nonparabolic model and as accurate as the full band model. Furthermore, the influence of the band model on the simulation results is also investigated. We show that the dispersion relation and density of states are all important in the simulation.
Źródło:
Acta Physica Polonica A; 2000, 98, 1-2; 123-130
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wave propagation in piezoelectric rings with rectangular cross-sections
Autorzy:
Zhang, X.
Wang, Y.
Chen, H.
Powiązania:
https://bibliotekanauki.pl/articles/279995.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
piezoelectric rings
orthogonal polynomial
guided wave
dispersion curves
Opis:
The ring ultrasonic transducers are widely used in the ocean engineering and medical fields. This paper employs an extended orthogonal polynomial approach to solve the guided wave propagation in two-dimensional structures, i.e. piezoelectric rings with rectangular cross- -sections. The extended polynomial approach can overcome the drawbacks of the conven- tional orthogonal polynomial approach which can be used to solve wave propagation in one-dimensional structures. Through numerical comparison with the available results for a rectangular aluminum bar, the validity of the present approach is illustrated. The dispersion curves and displacement and electric potential distributions of various rectangular piezo- electric rings are calculated, and the effects of different radius to thickness ratios, width to height ratios and polarizing directions on the dispersion curves are illustrated.
Źródło:
Journal of Theoretical and Applied Mechanics; 2015, 53, 3; 673-682
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation and Characterization of CL-20/EPDM by a Crystal Refinement and Spray Drying Method
Autorzy:
Ji, W.
Li, X.
Wang, J.
Powiązania:
https://bibliotekanauki.pl/articles/358349.pdf
Data publikacji:
2015
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
CL-20/EPDM
spray drying
impact sensitivity
thermal stability
Opis:
A 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) based mixed explosive was prepared by a spray drying method using CL-20 suspended in hexane containing EPDM rubber (ethylene-propylene-diene monomer), and made into a stable suspension. The samples were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD), and their thermal stability and impact sensitivity were also measured. The results showed that the ethylene-propylene-diene-monomer rubber (EPDM) can be successfully coated on to the CL-20 crystal surface. Compared to refinement-spray CL-20, the impact sensitivity of CL-20/EPDM was significantly reduced. The characteristic drop height was increased from 28.12 to 39.78 cm. The thermal stability was better than refinement-spray CL-20.
Źródło:
Central European Journal of Energetic Materials; 2015, 12, 4; 831-840
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On controllability for fractional differential inclusions in Banach spaces
Autorzy:
Wang, J.
Li, X.
Wei, W.
Powiązania:
https://bibliotekanauki.pl/articles/256046.pdf
Data publikacji:
2012
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
controllability
fractional differential inclusions
Bohnenblust-Karlin's fixed point theorem
Opis:
In this paper, we investigate the controllability for systems governed by fractional differential inclusions in Banach spaces. The techniques rely on fractional calculus, multivalue mapping on a bounded set and Bohnenblust-Karlin's fixed point theorem.
Źródło:
Opuscula Mathematica; 2012, 32, 2; 341-356
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An integrated production and delay-time based preventive maintenance planning model for a multi-product production system
Model integrujący planowanie opartej na pojęciu czasu opóźnienia konserwacji zapobiegawczej oraz planowanie produkcji dla systemów produkcji wieloasortymentowej
Autorzy:
Liu, X.
Wang, W.
Peng, R.
Powiązania:
https://bibliotekanauki.pl/articles/1365965.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
production planning
preventive maintenance
delay time
integration
multi-product
planowanie produkcji
konserwacja zapobiegawcza
czas opóźnienia
integracja
wieloasortymentowy
Opis:
This paper integrates preventive maintenance and medium-term tactical production planning in a multi-product production system. In such a system, a set of products needs to be produced in lots during a specified finite planning horizon. Preventive maintenance is carried out periodically at the end of some production periods and corrective maintenance is always performed at failures. The system’s available production capacity can be affected by maintenance, since both planned preventive maintenance and unplanned corrective maintenance result in downtime loss during the planning horizon. In addition to the time used for preventive and corrective maintenance, our model considers the setup time and the product quality, as these are affected by the defects and failures of the system. Procedures are proposed to identify the optimal production plan and preventive maintenance policy simultaneously. Our objective is to minimize the sum of maintenance, production, inventory, setup, backorder costs and the costs of unqualified products within the planning horizon. A real case from a steel factory is presented to illustrate the model.
W niniejszej pracy zintegrowano proces konserwacji zapobiegawczej z procesem średnioterminowego taktycznego planowania produkcji w odniesieniu do systemu produkcji wieloasortymentowej. W takim systemie, zestaw wyrobów jest produkowany partiami w określonym, skończonym horyzoncie planowania. Konserwacja zapobiegawcza prowadzona jest okresowo pod koniec wybranych okresów produkcyjnych, natomiast w przypadku wystąpienia uszkodzenia wykonuje się konserwację korygującą. Konserwacja może mieć wpływ na dostępne moce produkcyjne systemu, jako że zarówno planowana konserwacja prewencyjna jak i nieplanowana konserwacja korygująca powodują straty związane z przestojem urządzeń w danym horyzoncie planowania. Oprócz czasu potrzebnego na konserwację zapobiegawczą i korygującą, nasz model uwzględnia czas konfiguracji urządzeń oraz jakość produktów, ponieważ one również zależą od defektów i awarii systemu. Zaproponowano procedury, które pozwalają na jednoczesne określenie optymalnego planu produkcji i optymalnej strategii konserwacji prewencyjnej. Naszym celem jest minimalizacja sumy kosztów konserwacji, produkcji, zapasów, konfiguracji urządzeń oraz zamówień oczekujących a także kosztów produktów, które nie zostały zakwalifikowane do wprowadzenia do obrotu w danym horyzoncie planowania. Model zilustrowano na przykładzie rzeczywistego przypadku z fabryki stali.
Źródło:
Eksploatacja i Niezawodność; 2015, 17, 2; 215-221
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-100 z 261

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