Skocz do pozycji: 1.

Tytuł:

Three-dimensional path-following control of an autonomous underwater vehicle based on deep reinforcement learning

Autorzy:

Liang, Zhenyu
Qu, Xingru
Zhang, Zhao
Chen, Cong

Powiązania:

https://bibliotekanauki.pl/articles/32898215.pdf

Data publikacji:

2022

Wydawca:

Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa

Tematy:

autonomous underwater vehicle (AUV)
three-dimensional path following
deep reinforcement learning-based control
lineof-sight guidance
controller chattering

Opis:

In this article, a deep reinforcement learning based three-dimensional path following control approach is proposed for an underactuated autonomous underwater vehicle (AUV). To be specific, kinematic control laws are employed by using the three-dimensional line-of-sight guidance and dynamic control laws are employed by using the twin delayed deep deterministic policy gradient algorithm (TD3), contributing to the surge velocity, pitch angle and heading angle control of an underactuated AUV. In order to solve the chattering of controllers, the action filter and the punishment function are built respectively, which can make control signals stable. Simulations are carried out to evaluate the performance of the proposed control approach. And results show that the AUV can complete the control mission successfully.

Źródło:

Polish Maritime Research; 2022, 4; 36-44
1233-2585

Pojawia się w:

Polish Maritime Research

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 2.

Tytuł:

A multi-model based adaptive reconfiguration control scheme for an electro-hydraulic position servo system

Autorzy:

Zhang, Zhao
Yang, Zhong
Liu, Shuchang
Chen, Shuang
Zhang, Xiaokai

Powiązania:

https://bibliotekanauki.pl/articles/2124780.pdf

Data publikacji:

2022

Wydawca:

Uniwersytet Zielonogórski. Oficyna Wydawnicza

Tematy:

fault tolerant control
electro hydraulic position
servo system
multiple model
adaptive control
reconfiguration control
sterowanie tolerujące uszkodzenia
serwomechanizm
sterowanie adaptacyjne

Opis:

Reliability and safety of an electro-hydraulic position servo system (EHPSS) can be greatly reduced for potential sensor and actuator faults. This paper proposes a novel reconfiguration control (RC) scheme that combines multi-model and adaptive control to compensate for the adverse effects. Such a design includes several fixed models, one adaptive model, and one reinitialized adaptive model. Each of the models has its own independent controller that is based on a complete parametrization of the corresponding fault. A proper switching mechanism is set up to select the most appropriate controller to control the current plant. The system output can track the reference model asymptotically using the proposed method. Simulation results validate robustness and effectiveness of the proposed scheme. The main contribution is a reconfiguration control method that can handle component faults and maintain the acceptable performance of the EHPSS.

Źródło:

International Journal of Applied Mathematics and Computer Science; 2022, 32, 2; 185--196
1641-876X
2083-8492

Pojawia się w:

International Journal of Applied Mathematics and Computer Science

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 3.

Tytuł:

Chinese cabbage BrMYB34.2 transcription factor regulates indolic glucosinolates biosynthesis in Arabidopsis

Autorzy:

Zhao, Y.
Zhang, Y.
Guo, X.
Ma, Y.
Zhang, P.
Liu, H.
Liu, G.
Guo, J.

Powiązania:

https://bibliotekanauki.pl/articles/12705984.pdf

Data publikacji:

2020

Wydawca:

Uniwersytet Przyrodniczy w Lublinie. Wydawnictwo Uniwersytetu Przyrodniczego w Lublinie

Opis:

Glucosinolates (GS) are a group of sulfur- and nitrogen-rich plant secondary metabolites that originate from amino acids and exist mainly in plants in the order Brassicales, such as Arabidopsis thaliana (Arabidopsis) and Chinese cabbage (Brassica rapa ssp. pekinensis). To date, several regulatory components responsible for GS biosynthesis have been identified in Arabidopsis. However, the functions of GS biosynthesis regulators in Chinese cabbage have not been clarified. In our current study, a putative ATR1/MYB34 orthologous gene, BrMYB34.2, was isolated from Chinese cabbage leaves. To investigate the function of this gene, we engineered Arabidopsis plants that overexpress BrMYB34.2 ectopically and phenotypic analysis was performed. Moreover, we assayed the accumulation levels of indolic GS (IGS) and aliphatic glucosinolates in transgenic plants and test the expression of key genes of IGS biosynthesis and tryptophan synthesis by Real-time quantitative PCR. And further analysed the resistance of transgenic plants in 5MT stress treatment. The results indicate that ectopic expression of the BrMYB34.2 gene in Arabidopsis was able to up-regulate the accumulation level of IGS due to the increased expression of IGS and Trp biosynthetic genes. Moreover, overexpression of BrMYB34.2 conferred Arabidopsis 5MT resistance. These results suggest that the BrMYB34.2 gene may function as one of the regulators of IGS and Trp biosynthesis in Chinese cabbage.

Źródło:

Acta Scientiarum Polonorum. Hortorum Cultus; 2020, 19, 1; 85-95
1644-0692

Pojawia się w:

Acta Scientiarum Polonorum. Hortorum Cultus

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 4.

Tytuł:

Identification of Ephedra species by phylogenetic analyses using matK and ITS1 sequences

Autorzy:

Zhao, Y.S.
Xie, L.X.
Mao, F.Y.
Cao, Z.
Wang, W.P.
Zhao, Q.P.
Zhang, X.H.

Powiązania:

https://bibliotekanauki.pl/articles/56673.pdf

Data publikacji:

2016

Wydawca:

Polskie Towarzystwo Botaniczne

Opis:

In this study, the species identifications of seven Ephedra plants, including three medicinal plants from the Pharmacopoeia of the People’s Republic of China, were conducted using phylogenetic analyses, and the method’s validity was verified. The phylogenetic trees constructed from the maturase-coding gene (matK) and internal transcribed spacer 1 (ITS1) sequences showed that the former could be used for identifying five Ephedra plants, Ephedra intermedia, E. equisetina, E. antisyphilitica, E. major, and E. aphylla, but it had less power to discriminate E. sinica and E. przewalskii, while the latter could distinguish five Ephedra plants, E. przewalskii, E. equisetina, E. antisyphilitica, E. major, and E. aphylla, but it had less power to discriminate E. sinica and E. intermedia. However, when the two genes were combined, the seven species could be completely distinguished from each other, especially the medicinal plants from the others, which is significant in developing their pharmaceutical uses and in performing quality control assessments of herbal medicines. The method presented here could be applied to the analysis of processed Ephedra plants and to the identification of the botanical origins of crude drugs. Additionally, we discovered that E. equisetina and E. major were probably closely related to each other, and that E. sinica, E. intermedia, and E. przewalskii also had a close genetic relationship.

Źródło:

Acta Societatis Botanicorum Poloniae; 2016, 85, 2
0001-6977
2083-9480

Pojawia się w:

Acta Societatis Botanicorum Poloniae

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 5.

Tytuł:

Abruptly autofocusing property of circular Pearcey vortex beams with different initial launch angles in harmonic potentials

Autorzy:

Liu, Xianglian
Zhang, Di
Zhao, Lijiao
Li, Pu
Zhang, Jianguo
Liu, Yi

Powiązania:

https://bibliotekanauki.pl/articles/2172824.pdf

Data publikacji:

2022

Wydawca:

Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej

Tematy:

autofocusing beam
optical vortices
Pearcey

Opis:

We have studied and explored the influence of different launch angles on the circular Pearcey beams (CPBs) without vortex or with vortex for the first time. Although launch angles can manipulate the focal length and the contrast of peak intensity of the CPBs, the shape and propagation trajectory of the CPBs maintain invariant. When the vortex is considered, the focal pattern and the contrast of peak intensity of the circular Pearcey vortex beams (CPVBs) can be changed by adjusting the magnitude of topological charges and the position of vortex. In addition, we have deliberated the propagation of the CPVBs under the action of double opposite optical vortices.

Źródło:

Optica Applicata; 2022, 52, 3; 417--428
0078-5466
1899-7015

Pojawia się w:

Optica Applicata

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 6.

Tytuł:

Erratum to: Quantifying soil hydraulic properties and their uncertainties by modified GLUE method

Autorzy:

Yan, Y.
Liu, J.
Zhang, J.
Li, X.
Zhao, Y.

Powiązania:

https://bibliotekanauki.pl/articles/26617.pdf

Data publikacji:

2018

Wydawca:

Polska Akademia Nauk. Instytut Agrofizyki PAN

Źródło:

International Agrophysics; 2018, 32, 2
0236-8722

Pojawia się w:

International Agrophysics

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 7.

Tytuł:

Functional traits related to environmental divergence in combination with phylogenetic relationship of Picea species

Autorzy:

Wang, M.
Wang, J.
Zhang, A.
Zhang, X.
Sun, S.
Zhao, C.

Powiązania:

https://bibliotekanauki.pl/articles/2077949.pdf

Data publikacji:

2018

Wydawca:

Polska Akademia Nauk. Instytut Dendrologii PAN

Tematy:

δ13C
P50
Picea
seeva
quantitative convergence index

Opis:

Background: Plants have adapted to fine-scale environmental heterogeneity through ecologically important traits, leading to new lineages. This suggests that differentiation of important traits has been beneficial to habitat partitioning among closely related species. However, the pattern of ecological divergences and differentiation of functional traits in combination with phylogenetic relationships have not been widely examined. Material and methods: To illustrate the pattern of ecological divergences of nine Picea species, spatial evolutionary and ecological vicariance analysis (seeva) was used to quantify and test the divergence between sister lineages. Five functional traits were measured in a common garden experiment. For all traits the quantitative convergence index (QVI) was determined. Furthermore, their relationships with divergent environmental variables were analyzed in the context of phylogenetic relationships. Results: Temperature variables (maximum temperature of warmest month and temperature annual range) split at basal nodes and precipitation variables (annual precipitation and precipitation of driest quarter) split at terminal nodes. Conservative traits were leaf mass per area (LMA) and net photosynthetic rate (Pn), which reflected selective retention when ancestors suffered cold environmental separation. Meanwhile, linear stomatal density (LSD), carbon-13 isotope ratio (δ13C) and water potential at 50% loss of hydraulic conductivity (P50) were convergent between species, but only P50 exhibited adaption to different precipitation conditions. The nine Picea species exhibit a distinct environmental divergence pattern. LMA and Pn were selectively retained when their ancestors were subjected to cold environmental separation. P50 was an important trait with respect to adaptation to precipitation differences. This research provided a new way of expounding the correlation between environment, functional traits and phylogeny, deepening our understanding of environmental divergence, trait differentiation and speciation.

Źródło:

Dendrobiology; 2018, 80; 131-142
1641-1307

Pojawia się w:

Dendrobiology

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 8.

Tytuł:

Molecular cloning, expression, purification and osteoblasts proliferation activity of sika deer thymosin beta10

Autorzy:

Zhao, D.
Zhao, Y.
Zhang, H.
Xu, Z.
Liu, M.
Wang, J.
Bai, X.

Powiązania:

https://bibliotekanauki.pl/articles/2087874.pdf

Data publikacji:

2017

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

affinity chromatography
cell proliferation
prokaryotic expression
sika deer
thymosin 10

Źródło:

Polish Journal of Veterinary Sciences; 2017, 4; 751-758
1505-1773

Pojawia się w:

Polish Journal of Veterinary Sciences

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 9.

Tytuł:

The direct and indirect effect of fire on radial growth of Pinus koraiensis trees in a northern temperate forest of China

Autorzy:

Gao, Lushuang
Zhang, Chunyu
Zhao, Xiuhai
Zhang, Li

Powiązania:

https://bibliotekanauki.pl/articles/956863.pdf

Data publikacji:

2017

Wydawca:

Polska Akademia Nauk. Instytut Dendrologii PAN

Tematy:

burned trees
growth pattern
competition
climate
korean pine

Opis:

The long-term effects of fire on the radial growth of Korean pines (Pinus koraiensis) in Changbai Mountain is poorly understood. In order to quantify the impact of fire on the radial growth of Korean pines, we measured ring widths and developed two tree-ring chronologies from 21 burned Korean pine trees that were damaged by fire in 1857 as well as 30 control trees in the Changbai Mountain Nature Reserve, China. As expected, the growth rates of the burned trees were slower than those of the control trees in the first five years following the fire. However, beginning six years after the fire, the growth of the burned trees increased considerably, and this period of increased growth lasted 13 years, with moderate growth occurring throughout the 1866 to 1871 period. A difference in growth rates between burned and control tress was also observed for the 20 years since temperatures began markedly increasing in 1980. Burned trees tended to respond negatively to monthly minimum temperature, precipitation, and vapor pressure deficits (VPD), whereas the positive relationship between those factors and radial growth of control trees became stronger. In addition, the significantly negative effect of competition on radial growth was only observed among burned trees. These results demonstrated that the negative and direct effect of damage to physiological plant processes by fire only affected the years shortly after a fire occurred and then became obscured by its indirect effects, such as differential responses to climate and competition, which did persist for a long time. The indirect effect on radial growth over time could be explained by the variability in the relative strength of climatic responses and competition caused by fire.

Źródło:

Dendrobiology; 2017, 78; 111-123
1641-1307

Pojawia się w:

Dendrobiology

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 10.

Tytuł:

Energy Levels and Oscillator Strength of Ni XXIII

Autorzy:

Hu, F.
Jiang, G.
Yang, J.
Zhang, J.
Zhao, X.

Powiązania:

https://bibliotekanauki.pl/articles/1493444.pdf

Data publikacji:

2011-09

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

31.15.V-
31.30.jc

Opis:

Energy levels and oscillator strengths have been calculated for the fine-structure transitions among the levels of the $(1s^2) 2s^2 2 p^2,$ $2s2 p^3,$ $2p^4,$ $2s^2 2p3s,$ $2s^2 2p3p,$ and $2s^2 2p3d$ configurations of Ni XXIII using the graspVU and FAC program. The extensive configuration interaction and relativistic effects have been included while generating the wave functions. The results are compared with other recent theoretical estimates, and their accuracy is assessed.

Źródło:

Acta Physica Polonica A; 2011, 120, 3; 429-437
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 11.

Tytuł:

Ferrite Decarburization of High Silicon Spring Steel in Three Temperature Ranges

Autorzy:

Zhao, F.
Zhang, C. L.
Liu, Y. Z.

Powiązania:

https://bibliotekanauki.pl/articles/350822.pdf

Data publikacji:

2016

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

surface decarburization
steel
oxidation
carbon diffusion

Opis:

Surface decarburization of high silicon spring steel in ambient air was studied. The experimental results confirmed the decarburized mechanism under A_C1 temperature, in the temperature range of A_C1-A_C3 and A_C3-G. Under A_C1 temperature, pearlite spheroidization and surface decarburization are carried out simultaneously and pearlite spheroidization is reinforced. Considering the oxidation loss depth, the “true ferrite decarburized depth” at 850 °C (A_C3-G) is still smaller than that at 760°C (A_C1-A_C3). That is because an “incubation period” must pass away before ferrite decarburization occurs in the temperature range of A_C3-G, and the ferrite decarburized rate is limited to being equal to the partial decarburized rate.

Źródło:

Archives of Metallurgy and Materials; 2016, 61, 3; 1715-1722
1733-3490

Pojawia się w:

Archives of Metallurgy and Materials

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 12.

Tytuł:

Influence of Polytetrafluorethylene on the Mechanical and Safety Properties of a Composite Modified Double Base Propellant

Autorzy:

Sun, S.
Zhang, T.
Zhao, B.
Zhang, G.
Li, X.
Luo, Y.

Powiązania:

https://bibliotekanauki.pl/articles/358296.pdf

Data publikacji:

2018

Wydawca:

Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego

Tematy:

PTFE fibres
CMDB propellant
mechanical properties
mechanical sensitivity
combustion

Opis:

A novel Composite Modified Double Base (CMDB) propellant, formed by mechanically mixing aluminium/polytetrafluorethylene (Al/PTFE) powders, was prepared through a rolling process. A variety of tests, such as tensile properties, particle size analysis etc., were carried out to study the influence of PTFE on the CMDB propellant properties. The PTFE deformed from particles to fibres under a uniform shear force, forming a fibre network which greatly improved the propellant’s mechanical properties. Compared to that of the CMDB propellant without PTFE, the elongation of the propellant containing 6% PTFE was increased by 26 times, and moreover, the impact strength was enhanced by 326% at −40 °C. Significantly, the propellant friction and impact sensitivities were reduced by 75.8% and 35.6%, respectively. In addition, the presence of PTFE in the propellant resulted in fluorination of the Al. The gaseous combustion product AlF3 reduced the propellant combustion agglomeration. Consequently, PTFE significantly promoted the propellant’s mechanical performance, decreased the shock (friction, impact) sensitivity and reduced combustion agglomeration.

Źródło:

Central European Journal of Energetic Materials; 2018, 15, 3; 468-484
1733-7178

Pojawia się w:

Central European Journal of Energetic Materials

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 13.

Tytuł:

Thermal conductivity of a Brown Earth soil as affected by biochars derived at different temperatures: Experiment and prediction with the Campbell model

Autorzy:

Zhao, B.
Li, L.
Zhao, Y.
Zhang, X.

Powiązania:

https://bibliotekanauki.pl/articles/2082959.pdf

Data publikacji:

2020

Wydawca:

Polska Akademia Nauk. Instytut Agrofizyki PAN

Tematy:

biochar
bulk density
thermal conductivity
Brown Earth soil
Campbell model

Opis:

Thermal conductivity is a significant heat transfer property of soil. However, the influence of biochar on this property is not well known. In this research, the influence of corn straw biochars prepared at 300, 500 and 700oC on the thermal conductivity of a Brown Earth (Hapli-Udic Cambisol, FAO) soil and its prediction using a Campbell model was examined. The outcomes revealed that the bulk densities of the soil markedly decreased with increases in the biochar amendment rates of 1, 3, and 5% in linear patterns. The reduction in bulk density was mainly attributed to an increase in soil porosity and organic carbon content. With increasing volumetric water contents (10, 20, 30 and 40%), the thermal conductivity of the soils significantly increased, whereas those of soils with biochar amendment were obviously less than that of the CK and the differences increased with the biochar application rates. The pyrolysis temperature of biochar exhibited a negligible effect on the bulk density and thermal conductivity of soils at large. Combining the linear reduction of bulk density with the biochar amendment rate into the Campbell model, well-fitting results for the variation inthermal conductivity versus volumetric water content were obtained and accurate values could be predicted.

Źródło:

International Agrophysics; 2020, 34, 4; 433-439
0236-8722

Pojawia się w:

International Agrophysics

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 14.

Tytuł:

Microstructures and Microwave-Absorbing Properties of ZnO Smoke from Zinc Leach Residue Treated by Carbothermal Reduction

Autorzy:

Ma, Zhiwei
Wang, Sheng
Du, Xueyan
Zhang, Ji
Zhao, Ruifeng
Zhang, Shengquan

Powiązania:

https://bibliotekanauki.pl/articles/2049146.pdf

Data publikacji:

2021

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

zinc leach residue
carbothermal reduction
ZnO smoke
microwave-absorbing properties

Opis:

Much zinc residue is produced during the traditional processes involved in zinc hydrometallurgy in the leaching stage: its composition is complex and valuable metals are difficult to recover therefrom. If not handled properly, it can lead to a waste of resources and environmental pollution. To solve this problem, zinc leach residue specimens were treated using the carbothermal reduction method (CTR) that is easy to operate and has a high energy utilisation rate. The methods, such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and scanning transmission electron microscopy (STEM) were used for analytical characterisation. Based on this, this research investigated a structure-function relationship between microstructures and microwave-absorbing properties of ZnO smoke from CTR-treated zinc leach residue. The results demonstrate that microstructures and macro-properties of ZnO smoke obtained at different temperatures differ greatly. Under conditions including a calcination temperature of 1250°C, holding time of 60 min, and addition of 50% and 10% of powdered coal and CaO separately, the ZnO content in the obtained smoke is 99.14%, with regular micron-sized ZnO particles therein. For these particles, the minimum reflection loss (RLmin) reached –25.56 dB at a frequency of 15.84 GHz with a matching thickness of 5 mm. Moreover, frequency bandwidth corresponding to RL < –10 dB can reach 2.0 GHz. ZnO smoke obtained using this method is found to have excellent microwave-absorbing performance, which provides a new idea for high-value applications of zinc-rich residue.

Źródło:

Archives of Metallurgy and Materials; 2021, 66, 4; 1163--1170
1733-3490

Pojawia się w:

Archives of Metallurgy and Materials

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 15.

Tytuł:

Experimental study of quartz classification in the enhanced gravity field using Falcon concentrator

Autorzy:

Zhang, Ling
Yang, Lu
Hou, Haochun
Zhao, Yan
Lin, Jun
Zhang, Zeliang
Bu, Caiyun
Zheng, Xinran
Fu, Dong

Powiązania:

https://bibliotekanauki.pl/articles/27323652.pdf

Data publikacji:

2023

Wydawca:

Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej

Tematy:

classification
enhanced gravity field
fine particles
fish-hook

Opis:

The classification and separation of minerals happen in the traditional gravity separation simultaneously. This paper focuses on the classification performance of quartz particles in the enhanced gravity field. The classification efficiency of single quartz particles decreased then increased with the increase of rotational angular velocity, while it decreased with the increase of backwash water pressure. The classification efficiency of -0.5 +0.25mm, -0.25 +0.125mm, -0.125 +0.074mm, -0.074 +0.045mm and -0.045mm quartz was higher than the corresponding narrow size of -0.5mm quartz in general. The “fish-hook” phenomenon appeared in the partition curve of -0.5mm quartz under small/large rotational angular velocity and small backwash water pressure, and the dip point could be found in fine particles region, which indicated that the “fish-hook” was closely related with operating parameters and particle size. A medium rotational angular velocity and larger backwash water pressure could be helpful to avoid the appearance of “fish-hook” in fine particles region and achieve a better classification performance. This investigation is beneficial to understand the regularity of particle migration in the enhanced gravity field.

Źródło:

Physicochemical Problems of Mineral Processing; 2023, 59, 6; art. no. 175242
1643-1049
2084-4735

Pojawia się w:

Physicochemical Problems of Mineral Processing

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 16.

Tytuł:

Flotation kinetics and separation selectivity of coal size fractions

Autorzy:

Li, Y.
Zhao, W.
Gui, X.
Zhang, X.

Powiązania:

https://bibliotekanauki.pl/articles/110676.pdf

Data publikacji:

2013

Wydawca:

Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej

Tematy:

coal
flotation rate
combustible matter recovery
ash
particle size

Opis:

Flotation recovery and kinetics for three size fractions of coal were investigated. Flotation of combustible matter recovery was approximated with the first order kinetic equation while flotation of the ash forming minerals with the second order equation. Next, the equations for each size fraction were combined and a formula was obtained which was used for approximation of the experimental results using the so-called Fuerstenau upgrading curve, which relates the recovery of combustible matter recovery and recovery of ash forming minerals, both in concentrate. The Fuerstenau upgrading plot showed that the best selectivity was obtained for the middle size fraction of 0.25–0.075 mm, while the flotation selectivity of larger 0.5–0.25 mm and smaller –0.075 mm particles was diminished. This finding agrees with many other investigations.

Źródło:

Physicochemical Problems of Mineral Processing; 2013, 49, 2; 387-395
1643-1049
2084-4735

Pojawia się w:

Physicochemical Problems of Mineral Processing

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 17.

Tytuł:

Prefabricated fractured rock under stepwise loading and unloading

Autorzy:

Zhang, Wei
Zhao, Tongbin
Yin, Yanchun

Powiązania:

https://bibliotekanauki.pl/articles/2086954.pdf

Data publikacji:

2022

Wydawca:

Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej

Tematy:

fractured rock
graded loading and unloading
rock deformation
energy evolution
acoustic emission

Opis:

After the engineering rock mass has been affected by comprehensive effects of mining and disturbance, it experiences an input of external energy as well as dissipation and release of internal energy. From the viewpoint of energy, characteristics of rock failure are studied, and the law of rock unstable deformation and energy evolution is analyzed. The damage mechanism of rock is revealed easily. A gradual loading and unloading test of fractured rock is carried out to analyze deformation characteristics of the fractured rock during the load- -bearing process, and to study the law of energy dissipation and release under different load- ing and unloading stress levels. The results show that: (1) the load-bearing time, loading and unloading stress level, stress at crack initiation and peak stress of fractured rock gradually decrease with an increase in the number of cracks, and the descending speed decreases grad- ually with the increase in the number of cracks; (2) the strain at crack initiation and peak strain of the fractured rock increase gradually with an increase in the number of cracks, and the gathering speed decreases with the increase of the number of cracks; (3) the released strain energy and dissipation energy of fractured rock increase with an increase of loading and unloading stress levels, and the increasing rate gradually slows down; (4) the number of acoustic emission events is positively related to the degree of rock damage, and the increase in the number of cracks will prolong duration of the number of acoustic emission events. The results have a theoretical value for energy evolution and deformation damage of fractured rock masses, and also provide experimental experience to study the instability precursor information of rock materials from the viewpoint of energy.

Źródło:

Journal of Theoretical and Applied Mechanics; 2022, 60, 1; 167--179
1429-2955

Pojawia się w:

Journal of Theoretical and Applied Mechanics

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 18.

Tytuł:

Improved classification robust Kalman filtering method for precise point positioning

Autorzy:

Zhang, Qieqie
Zhao, Long
Zhou, Jianhua

Powiązania:

https://bibliotekanauki.pl/articles/220468.pdf

Data publikacji:

2019

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

Kalman filter
classification robust
equivalent weight function
precise point positioning

Opis:

The accuracy and reliability of Kalman filter are easily affected by the gross errors in observations. Although robust Kalman filter based on equivalent weight function models can reduce the impact of gross errors on filtering results, the conventional equivalent weight function models are more suitable for the observations with the same noise level. For Precise Point Positioning (PPP) with multiple types of observations that have different measuring accuracy and noise levels, the filtering results obtained with conventional robust equivalent weight function models are not the best ones. For this problem, a classification robust equivalent weight function model based on the t-inspection statistics is proposed, which has better performance than the conventional equivalent weight function models in the case of no more than one gross error in a certain type of observations. However, in the case of multiple gross errors in a certain type of observations, the performance of the conventional robust Kalman filter based on the two kinds of equivalent weight function models are barely satisfactory due to the interaction between gross errors. To address this problem, an improved classification robust Kalman filtering method is further proposed in this paper. To verify and evaluate the performance of the proposed method, simulation tests were carried out based on the GPS/BDS data and their results were compared with those obtained with the conventional robust Kalman filtering method. The results show that the improved classification robust Kalman filtering method can effectively reduce the impact of multiple gross errors on the positioning results and significantly improve the positioning accuracy and reliability of PPP.

Źródło:

Metrology and Measurement Systems; 2019, 26, 2; 267-281
0860-8229

Pojawia się w:

Metrology and Measurement Systems

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 19.

Tytuł:

Optimization of sealing parameters of double-sealing pipeline repair clamp

Autorzy:

Zhao, Bingjie
Zhang, Shuli
Gao, Qijun
Miao, Canliang
Wang, Tongyu

Powiązania:

https://bibliotekanauki.pl/articles/2086977.pdf

Data publikacji:

2022

Wydawca:

Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej

Tematy:

seal
rubber
pressure
the orthogonal experimental design

Opis:

Considering the key equipment of the pipeline clamp repair technology, this paper analyzes design of the pipeline repair clamp. Based on the damaged pipeline repair requirements, the design of a double-sealing pipeline repair clamp is established. The subsea pipeline in the Bohai Bay is considered as an example to develop a finite element model of a double sealing structure and calculate the sealing capacity, targeting a sealing pressure of 6MPa. The parameters affecting the sealing capacity are studied. For circumferential sealing, the effects of distance between the rubber and the pipeline, distance between the ring and the pipeline, and the contact friction coefficient on the sealing capacity are analyzed. The design parameters of circumferential sealing are optimized by an orthogonal experimental design method. Further, the effect of the friction coefficient on the axial sealing capacity is studied, and design suggestions are put forward based on the analysis. The results of this study can provide guidance for the design and application of subsea pipeline repair clamps.

Źródło:

Journal of Theoretical and Applied Mechanics; 2022, 60, 3; 333--346
1429-2955

Pojawia się w:

Journal of Theoretical and Applied Mechanics

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 20.

Tytuł:

Laser frequency stability estimation and velocity measurement in the atmosphere with self-heterodyne

Autorzy:

Zhang, H.
Wang, H.
Zhao, S.

Powiązania:

https://bibliotekanauki.pl/articles/174066.pdf

Data publikacji:

2016

Wydawca:

Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej

Tematy:

frequency stability
atmospheric propagation
self-heterodyne
Doppler velocity

Opis:

We present a novel method of self-heterodyne for laser frequency stability estimation in the atmosphere. At the same time, it is used in the Doppler velocity measurement for moving targets in the atmosphere. The transmission range is 16.2 km (round-trip propagation with 8.1 km) in the horizontal atmospheric path, and the measuring results showed that the frequency stability of the whole laser detection system is 53.4 kHz with 20.7 kHz stand deviation. This frequency stability is the integrated influence with the whole detection system not just for the laser, but it can be considered as the estimation of the laser’s frequency stability. It is much more practical for the heterodyne detection in the atmosphere. At last, the method of self-heterodyne was used for 16.2 km round trip velocity measurement. It is showed that the velocity absolute error is less than 1.5 cm/s in the turbulent atmosphere, and the relative error is not higher than 5%.

Źródło:

Optica Applicata; 2016, 46, 2; 305-316
0078-5466
1899-7015

Pojawia się w:

Optica Applicata

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 21.

Tytuł:

An integrated approach to estimate storage reliability with masked data from series system

Autorzy:

Zhang, Yongjin
Zhao, Ming

Powiązania:

https://bibliotekanauki.pl/articles/27322965.pdf

Data publikacji:

2023

Wydawca:

Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN

Tematy:

storage reliability
masked data
EM-LS algorithm
series system
LS method

Opis:

Storage reliability is of importance for the products that largely stay in storage in their total life-cycle such as warning systems for harmful radiation detection, and many kinds of defense systems, etc. Usually, the field-testing data can be available, but the failure causes for a series system cannot be always known because of the masked information. In this paper, the storage reliability model with possibly initial failures is studied on the statistical analysis method when the masked data are considered. To optimize the use of the masked survival data from storage systems, a technique based on the least squares (LS) method with an EM-like algorithm, is proposed for the series system. The parametric estimation procedure based on the LS method is developed by applying the algorithm to update the testing data, and then the LS estimation for the initial reliability and failure rate of the components constituting the series system are investigated. In the case of exponentially distributed storage lifetime, a numerical example is provided to illustrate the method and procedure. The results should be useful for accurately evaluating the production reliability, identifying the production quality, and planning a storage environment.

Źródło:

Eksploatacja i Niezawodność; 2023, 25, 4; art. no. 172922
1507-2711

Pojawia się w:

Eksploatacja i Niezawodność

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 22.

Tytuł:

Numerical modeling of hydrodynamic and sediment siltation due to typhoon in estuary channel regulation

Autorzy:

Zhao, H.
Zhang, Q.
Xie, M.

Powiązania:

https://bibliotekanauki.pl/articles/259087.pdf

Data publikacji:

2015

Wydawca:

Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa

Tematy:

Oujiang Estuary
numerical model
channel regulation
sediment siltation
typhoon

Opis:

Oujiang Estuary is a complex tidal estuary with many channels and shoals in the East China Sea, which was affected by typhoon frequently. The navigation channel of Wenzhou Port is located in the north branch of Oujiang Estuary, which happened serious sediment siltation in many times due to typhoon impact. The regulation is considered to decrease siltaion of the channel and protect shoals as well. According to the site survey data, the mathematic model is established and validated, which simulates the hydrodynamic, sediment transport and channel siltation due to typhoon in Oujiang Estuary. The channel regulation scenario is studied by the model simulation after analysis of the silation character. It indicates that the high concentration sediment from shoals north of channel is main sediment source caused siltation in the channel, which can be prevented into the channel by the regulation scenario and decrease siltation efficiently.

Źródło:

Polish Maritime Research; 2015, S 1; 61-66
1233-2585

Pojawia się w:

Polish Maritime Research

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 23.

Tytuł:

Molecular cloning and expression analysis of CML27 in Brassica oleracea pollination process

Autorzy:

Lian, X.P.
Zeng, J.
Zhang, H.C.
Yang, X.H.
Zhao, L.
Zhu, L.Q.

Powiązania:

https://bibliotekanauki.pl/articles/19583.pdf

Data publikacji:

2018

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Źródło:

Acta Biologica Cracoviensia. Series Botanica; 2018, 60, 2
0001-5296

Pojawia się w:

Acta Biologica Cracoviensia. Series Botanica

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 24.

Tytuł:

Study of the Effect of DINA on the Polymorphic Transition of ε-CL-20 in Composite Modified Double Base Propellants

Autorzy:

Wu, Zongkai
Zheng, Wei
Pei, Jiangfeng
Chen, Zhiqun
Zhang, Jun
Song, Xiuduo
Wang, Jiangning
Zhang, Dongxiang
Zhao, Fengqi

Powiązania:

https://bibliotekanauki.pl/articles/27788019.pdf

Data publikacji:

2021

Wydawca:

Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego

Tematy:

CMDB propellant
CL-20
DINA
polymorphic transition

Opis:

Abstract: The polymorphic transition of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazatetracyclo[5.5.0.05,9.03,11]dodecane (CL-20) is influenced by the materials and conditions used in the preparation of propellants, and limits the application of ε-CL-20 in solid propellants. In the present work, the effect of dinitroxydiethylnitramine (DINA) on the polymorphic transition of ε-CL-20 in CMDB propellants was investigated by Raman spectroscopy and the Calvet microcalorimeter method. The performance of propellants with CL-20 as affected by DINA was studied by the theoretical prediction of their energetic parameters, stability, combustion, and mechanical tests, respectively. The results showed that the polymorphic transition temperature of ε-CL-20 to α-CL-20 can be reduced to 75 °C by DINA. Expansion of the crystal volume during the process of the ε-CL-20 to α-CL-20 transition will produce obvious cracks in the surface of the crystals. NC/NG can inhibit the effect of DINA on the polymorphic transition of ε-CL-20. The theoretically predicted results indicated that adding DINA will not lower the energy level of CMDB propellants containing CL-20. The DSC and VST results showed that CL-20 has good compatibility and thermal stability with DINA. The burning rate tests revealed that adding DINA decreases the burning rates of CMDB propellants containing CL-20. Mechanical property testing showed that adding DINA can clearly improve the mechanical properties of CMDB propellants containing CL-20. The results of these investigations suggested that DINA has no effect on the crystalline stability of ε-CL-20 in the solventless extrusion process, which contributes to a significant understanding of practical applications and provides guidance for applied research on the use of CL-20 in propellants.

Źródło:

Central European Journal of Energetic Materials; 2021, 18, 2; 165--182
1733-7178

Pojawia się w:

Central European Journal of Energetic Materials

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 25.

Tytuł:

Interior Perforation Flow Field Study of Partially Cut 7-Perforated Stick Propellants

Autorzy:

Zhao, Xiaoliang
Zhang, Xiaobing

Powiązania:

https://bibliotekanauki.pl/articles/358092.pdf

Data publikacji:

2019

Wydawca:

Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego

Tematy:

partially cut
7-perforation stick propellants
internal perforation flow field
pressure difference
gas velocity

Opis:

Partially cut 7-perforated propellants are used in gun charges because of their good flame spreading, high progressivity and loading density. To investigate the complex flow field in a partially cut multi-perforation stick propellant, a steady three-dimensional model for compressible viscid internal perforation and the vent gas region flow field was established and simulated by ANSYS Fluent. The results illustrate that the cut vent can decrease the internal perforation pressure and end face gas velocity. Moreover, the mass that escaped through the vent to the outside was 85.3% of the whole internal burning propellant gas. When the width of the cut slot was larger than half the diameter, the internal pressure decreased weakly and the progressive intensity decreased slightly as the cut slot was increased. As the same side intervals were increased or the perforation diameters were decreased, the end face gas velocity and the internal and external perforation pressure differences increased, and the propellant combustion area progressive intensity increased. As the web thickness increased, the internal pressure increased, and gas velocity exhibited an upward tendency and reached peak values when 2e1 = 0.84 mm, whilst the progressive intensity increased slightly.

Źródło:

Central European Journal of Energetic Materials; 2019, 16, 4; 564-582
1733-7178

Pojawia się w:

Central European Journal of Energetic Materials

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 26.

Tytuł:

Human neutrophil peptide 3 could be functionally expressed in Rhodobacter sphaeroides

Autorzy:

Nie, Xin
Zhang, Li
Hu, Zongli
Liu, Yi
Zhao, Zhiping

Powiązania:

https://bibliotekanauki.pl/articles/1039101.pdf

Data publikacji:

2015

Wydawca:

Polskie Towarzystwo Biochemiczne

Tematy:

Rb. sphaeroides
HNP3
expression system
antimicrobial activity
spectral absorption

Opis:

Human neutrophil peptides (HNPs) possess high antimicrobial activities against a broad spectrum of microorganisms. Rhodobacter sphaeroides is the best-characterized photosynthetic bacterium and exhibits potential as a novel expression system. Up to date, no literature has been reported regarding expression of HNP3 in Rb. sphaeroides. In the present study, the HNP3 gene fragment was amplified by SOE PCR and ligated into photosynthetic bacteria light-harvesting complex 2 (LH2) expression vector leading to HNP3 fusion protein expression vector. The HNP3 fusion protein was successfully expressed as rapidly evaluated by the LH2 characteristic peaks at ~800 nm and ~850 nm before purification and SDS/PAGE. Subsequently, the HNP3 fusion protein was purified by one-step affinity chromatography, and could be rapidly detected by the color and the spectral absorption at ~800 nm and ~850 nm before SDS/PAGE. Antimicrobial activity assay suggested that the HNP3 fusion protein exhibited high antimicrobial activity towards E. coli. The present study may supply an insight into employing the novel Rb. sphaeroides expression system, exhibiting dramatic advantages over currently used commercial expression system, to heterologously express human neutrophil peptides.

Źródło:

Acta Biochimica Polonica; 2015, 62, 2; 259-263
0001-527X

Pojawia się w:

Acta Biochimica Polonica

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 27.

Tytuł:

Quantifying soil hydraulic properties and their uncertainties by modified GLUE method

Autorzy:

Yan, Yifan
Liu, Jianli
Zhang, Jiabao
Zhao, Yongchao
Xiaopeng, Li

Powiązania:

https://bibliotekanauki.pl/articles/973010.pdf

Data publikacji:

2017

Wydawca:

Polska Akademia Nauk. Instytut Agrofizyki PAN

Tematy:

soil hydraulic properties
uncertainty
generalized likelihood uncertainty estimation
evaporation experiment

Opis:

Nonlinear least squares algorithm is commonly used to fit the evaporation experiment data and to obtain the ‘optimal’ soil hydraulic model parameters. But the major defects of nonlinear least squares algorithm include non-uniqueness of the solution to inverse problems and its inability to quantify uncertainties associated with the simulation model. In this study, it is clarified by applying retention curve and a modified generalised likelihood uncertainty estimation method to model calibration. Results show that nonlinear least squares gives good fits to soil water retention curve and unsaturated water conductivity based on data observed by Wind method. And meanwhile, the application of generalised likelihood uncertainty estimation clearly demonstrates that a much wider range of parameters can fit the observations well. Using the ‘optimal’ solution to predict soil water content and conductivity is very risky. Whereas, 95% confidence interval generated by generalised likelihood uncertainty estimation quantifies well the uncertainty of the observed data. With a decrease of water content, the maximum of nash and sutcliffe value generated by generalised likelihood uncertainty estimation performs better and better than the counterpart of nonlinear least squares. 95% confidence interval quantifies well the uncertainties and provides preliminary sensitivities of parameters.

Źródło:

International Agrophysics; 2017, 31, 3; 433-445
0236-8722

Pojawia się w:

International Agrophysics

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 28.

Tytuł:

Research on vibration evolution of a ball bearing without the cage under local variable-diameter raceway damage

Autorzy:

Zhou, Enwen
Zhao, Yanling
Zhang, Huanqing

Powiązania:

https://bibliotekanauki.pl/articles/2200877.pdf

Data publikacji:

2023

Wydawca:

Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej

Tematy:

ball bearing
vibration evolution
variable-diameter raceway
damage

Opis:

This article presents an analysis of vibration evolution of a ball bearing without the cage. A vibration model in which time-varying displacement, time-varying stiffness, contact force and collision force are comprehensively considered, is proposed. On this basis, the law of motion of the bearing is studied. It is shown that a variable-diameter raceway affects the radius of curvature, which effects the dispersion of rolling elements. The damaged variable -diameter raceway leads to discrete failure, contact force and collision force of rolling elements, which are main reasons that cause vibration mutation. The bearing motion changes from quasi-periodic to chaotic motion.

Źródło:

Journal of Theoretical and Applied Mechanics; 2023, 61, 1; 129--146
1429-2955

Pojawia się w:

Journal of Theoretical and Applied Mechanics

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 29.

Tytuł:

Acoustic emission characteristics of deep granite under triaxial cylic loading and unloading

Autorzy:

Pei, Feng
Zhang, Yue-Zheng
Zhao, Ji-Wei
Geng, Jing-Ming

Powiązania:

https://bibliotekanauki.pl/articles/1402362.pdf

Data publikacji:

2020

Wydawca:

Politechnika Wrocławska. Wydział Geoinżynierii, Górnictwa i Geologii. Instytut Górnictwa

Tematy:

deep granite
acoustic emission
frequency spectrum
precursory feature recognition

Opis:

In order to obtain the damage and AE characteristics of deep granite, TAW-2000 electrohydraulic servo rigid testing equipment and PCI-2 acoustic emission acquisition system were used to clarify the relationship between AE characteristics and stress level under conventional triaxial and cyclic loading and unloading. The results show that: AE characteristic parameters such as counts and energy under different confining pressures have good consistency in reflecting cracks growth process, which correspond to the stress level of rock sample; Before the critical failure, the AE amplitude increases significantly and extremely high peak frequency and extremely low peak frequency began to appear; The phenomenon that peak frequency band number increases significantly can be used as the precursor of rock failure; The change trend of characteristic parameters, amplitude and peak frequency band were related to the stress level of rock, and the loading path has little influence on it, which verified the effectiveness of AE precursory feature recognition; FR value decreases continuously with the increase of cyclic stress level and overall trend is downward, which indicated that AE memory gradually decreases as the stress level increases; From the perspective of damage mechanics, the AE characteristics of rock before failure are explained reasonably by the development of damage rate.

Źródło:

Mining Science; 2020, 27; 209-225
2300-9586
2353-5423

Pojawia się w:

Mining Science

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 30.

Tytuł:

Dynamic characteristics study on the two-stage safety valve used on hydraulic support under impact loading

Autorzy:

Zhao, Guochao
Wang, Hui
Song, Yuning
Zhang, Changshuai

Powiązania:

https://bibliotekanauki.pl/articles/2055035.pdf

Data publikacji:

2020

Wydawca:

Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej

Tematy:

safety valve
impact loading
hydraulic support
dynamic characteristic

Opis:

A two-stage linkage safety valve for hydraulic support is presented. Considering the hydraulic support is impacted, dynamic simulation of the column circuit with the two-stage safety valve subject impact loading was carried out, and the dynamic characteristics of the two- -stage safety valve with different impact forms were studied. A rapid impact loading test rig was built to test the two-stage safety valve sample under impact loading. Simulation and experimental results indicate that the two-stage safety valve has high sensitivity and good unloading performance, it can realize fast and large flow unloading of the hydraulic support under different impact forms and pressures.

Źródło:

Journal of Theoretical and Applied Mechanics; 2020, 58, 3; 623--635
1429-2955

Pojawia się w:

Journal of Theoretical and Applied Mechanics

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 31.

Tytuł:

An improved resonant thermal converter based on micro-bridge resonator

Autorzy:

Dong, L.
Han, J.
Zhang, P.
Zhao, Z.
Cheng, B.
Han, D.

Powiązania:

https://bibliotekanauki.pl/articles/220878.pdf

Data publikacji:

2018

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

thermoelectric transfer difference
micro-bridge resonator
thermal converter
bifilar heater

Opis:

This paper presents the design, fabrication and testing of an improved thin-film thermal converter based on an electro-thermally excited and piezo-resistively detected micro-bridge resonator. The resonant thermal converter comprises a bifilar heater and an opposing micro-bridge resonator. When the micro-bridge resonator absorbs the radiant heat from the heater, its axial strain changes, then its resonant frequency follows. Therefore the alternating voltage or current can be transferred to the equivalent DC quantity. A non-contact temperature sensing mechanism eliminates heat loss from thermopiles and reduces coupling capacitance between the temperature sensor and the heater compared with traditional thin-film thermal converters based on thermopiles. In addition, the quasi-digital output of the resonant thin-film thermal converter eliminates such problems as intensity fluctuations associated with analogue signals output by traditional thin-film thermal converters. Using the fast-reversed DC (FRDC) method, the thermoelectric transfer difference, which determines the frequency-independent part of the ac-dc transfer difference, is evaluated to be as low as 1.1 · 10^-6. It indicates that the non-contact temperature sensing mechanism is a feasible method to develop a high-performance thermal converter.

Źródło:

Metrology and Measurement Systems; 2018, 25, 4; 715-725
0860-8229

Pojawia się w:

Metrology and Measurement Systems

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 32.

Tytuł:

Bacterial communities in PM2.5 and PM10 in broiler houses at different broiler growth stages in spring

Autorzy:

Zhang, J.
Li, Y.
Xu, E.
Jiang, L.
Tang, J.
Li, M.
Zhao, X.
Chen, G.
Zhu, H.
Yu, X.
Zhang, X.

Powiązania:

https://bibliotekanauki.pl/articles/2087465.pdf

Data publikacji:

2019

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

bacterial communities
broilers
high-throughput sequencing
particulate matter

Źródło:

Polish Journal of Veterinary Sciences; 2019, 3; 495-504
1505-1773

Pojawia się w:

Polish Journal of Veterinary Sciences

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 33.

Tytuł:

Theoretical Studies on the Local Structure and Spin Hamiltonian Parameters for Single Cu²⁺ Ion in BaF₂

Autorzy:

Lin, J.
Xiao, P.
Zhao, Y.
Zhang, B.
Yang, Y.

Powiązania:

https://bibliotekanauki.pl/articles/1398965.pdf

Data publikacji:

2016-06

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

75.10.Dg
76.30.Fc

Opis:

The spin Hamiltonian parameters (g-factors and the hyperfine structure constants) and local structure are theoretically studied for single Cu²⁺ ion in BaF₂ from the high-order perturbation formulae of these parameters for 3d⁹ ions in tetragonally elongated octahedra. In the calculations, the ligand orbital and spin-orbit coupling of the impurity Cu²⁺ are taken into account, based on the cluster approach. Due to the Jahn-Teller effect and size mismatching substitution, the impurity Cu²⁺ is found to be located at a distance of about 0.2 Å from the nearest fluorine plane. The signs of the hyperfine structure constants $A_∥ $ and $ A_⊥ $ are suggested. The theoretical spin Hamiltonian parameters based on the above local structure are in good agreement with the observed values.

Źródło:

Acta Physica Polonica A; 2016, 129, 6; 1173-1177
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 34.

Tytuł:

Aging behavior of the three-proof polyurethane coating under UV radiation
Wpływ promieniowania UV na starzenie trójwarstwowej powłoki poliuretanowej

Autorzy:

Wang, Jianfa
Gu, Zheng
Zhao, Jie
Zhang, Susu
Li, Peiyao
Meng, Chao
Sui, Jinyong
Zhang, Xiaoyi
Hu, Shaokai
Pan, Jiaying
Li, Junyi

Powiązania:

https://bibliotekanauki.pl/articles/2202627.pdf

Data publikacji:

2022

Wydawca:

Sieć Badawcza Łukasiewicz - Instytut Chemii Przemysłowej

Tematy:

polyurethane
ultraviolet
coating
resin
poliuretan
ultrafiolet
powłoka
żywica

Opis:

The influence of UV radiation on the gloss, structure (SEM, FTIR), thermal (TGA, DTG) and mechanical properties of polyurethane resins and the three-layer protective coating made of them was investigated. The gloss of the resins was greater than that of the protective coating. UV radiation has been proven to reduce gloss (at 1,200 hours irradiation, 81.3° to 8.9° for resins, and 61.1° to 2.8° for coating).The tensile strength of the resins decreased during aging, and the relative elongation at break after reaching the minimum was increased (at the irradiation time of 100 h). In the case of coating, both the tensile strength and elongation decreased during aging and, after reaching the minimum they increased (at the irradiation time of 800 h), reaching the maximum (at the irradiation time of 1000 h), and then decreased.
Zbadano wpływ promieniowania UV na połysk, strukturę (SEM, FTIR), właściwości termiczne (TGA, DTG) i mechaniczne żywic poliuretanowych oraz wykonanej z nich trójwarstwowej powłoki ochronnej. Połysk żywic był większy niż powłoki ochronnej. Potwierdzono, że promieniowanie UV zmniejsza połysk (przy naświetlaniu przez 1200 godzin, w przypadku żywic z 81,3° do 8,9°, a w przypadku powłok z 61,1° do 2,8°). Wytrzymałość na rozciąganie żywic zmniejszała się w trakcie starzenia, a wydłużenie względne przy zerwaniu po osiągnięciu minimum zwiększało (przy czasie naświetlania 100 h). W przypadku powłoki zarówno wytrzymałość na rozciąganie, jak i wydłużenie zmniejszały się w trakcie starzenia i po osiągnięciu minimum zwiększały (przy czasie naświetlania 800 h), osiągając maksimum (przy czasie naświetlania 1000 h), a następnie zmniejszały.

Źródło:

Polimery; 2022, 67, 9; 433--437
0032-2725

Pojawia się w:

Polimery

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 35.

Tytuł:

Fatigue Behavior and Mechanism of FV520B-I Owing to the Effect of Loading Frequency on the Fatigue Property in HCF and VHCF Regime

Autorzy:

Wang, J.
Zhang, Y.
Shi, B.
Zhao, Q.
Sun, Q.
Zhang, Z.
Lu, H.

Powiązania:

https://bibliotekanauki.pl/articles/353784.pdf

Data publikacji:

2018

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

ultrahigh loading frequency
FV520B-I
fatigue strength
fatigue conversion model

Opis:

Fatigue property of FV520B-I is affected by the ultrahigh loading frequency significantly, and the ultrasonic fatigue experimental data can’t be employed directly to analyze the fatigue failure in the actual remanufacturing engineering. However few theories about the effect of loading frequency on the fatigue property of FV520B-I has ever been proposed. In this paper, both ultrasonic experiment and conventional experiment are conducted out to obtain the fatigue data. The effect of loading frequency on the fatigue data distribution is discussed firstly, its fatigue limit declines with the increase of the loading frequency. Then the fracture surface observations are captured, the fatigue property and fatigue behavior mechanism of FV520B-I is examined by analyzing the fracture surface features, crack initiation and failure observations. A new material frequency correction factor is proposed and introduced to eliminate the influence of the loading frequency on the FV520B-I fatigue property. FV520B-I empirical fatigue life conversion model and fatigue strength conversion model are established with comprehensive use of a fitting algorithm based on the combination of experimental data and classic formula. A clear understand of the effect of loading frequency on the fatigue property of FV520B-I is novel and has an important significance in guaranteeing the accuracy of the actual fatigue analysis of FV520B-I in the remanufacturing engineering.

Źródło:

Archives of Metallurgy and Materials; 2018, 63, 1; 347-357
1733-3490

Pojawia się w:

Archives of Metallurgy and Materials

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 36.

Tytuł:

Low atmospheric density measurement based on Rayleigh scattering of an ultraviolet laser

Autorzy:

Wang, R
Yao, J.
Zhong, K.
Miao, Y.
Cui, H.
Zhao, X.
Zhang, C.

Powiązania:

https://bibliotekanauki.pl/articles/174910.pdf

Data publikacji:

2013

Wydawca:

Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej

Tematy:

atmospheric density measurement
Rayleigh scattering
ultraviolet laser

Opis:

The qualitative measurement of low atmospheric density in the air flow field has been investigated in this paper. The supersonic flow field with Mach number of 1.5 around the NACA0006 aerofoil has been numerically simulated and the transient slight pressure and low density atmosphere have been experimentally determined based on Rayleigh scattering of a 266 nm ultraviolet laser. The scattering patterns have been effectively captured under different atmospheric pressure of 4.5, 92, 470 and 710 Pa with laser energy of only 0.5 mJ. It has been demonstrated that in the pressure range from 4.5 to 1100 Pa, corresponding to the atmospheric density from 4.8105×10–5 kg/m3 to 1.279×10–2 kg/m3, the scattering intensity of an ultraviolet laser is linear to the pressure and density with the slope coefficient of 0.00968 a.u./Pa and 0.83226 a.u./(kg/m3×10–3). It has been proved that Rayleigh scattering is a promising technology for observation of instantaneous and multidimensional distribution of a supersonic flow field.

Źródło:

Optica Applicata; 2013, 43, 3; 597-605
0078-5466
1899-7015

Pojawia się w:

Optica Applicata

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 37.

Tytuł:

COMBINATION OF BERBERINE AND MATRINE AFFECTS APOPTOSIS AND CELLCYCLE IN HUMAN CERVICAL CANCER CELLS

Autorzy:

Zhang, Qijiayu
Sun, Yi
Huang, Yuxi
Sun, Jing
Zhao, Chongbo
Song, Yijun
Wu, Juanhua

Powiązania:

https://bibliotekanauki.pl/articles/895719.pdf

Data publikacji:

2019-12-29

Wydawca:

Polskie Towarzystwo Farmaceutyczne

Tematy:

apoptosis
cervical cancer
Matrine
berberine

Opis:

Cervical cancer is the fourth leading cause of malignancy-related mortality in women worldwide, and effective advanced-stage therapies are urgently required. Berberine is a quaternary ammonium compound extracted from traditional Chinese medicinal herbs, including Phellodendron spp., with antibacterial and antitumor activities. Matrine, the main active ingredient of Sophora flavescens rhizomes, has not only traditionally described health effects but is also widely used for its anticancer, anti-inflammatory, immunoregulatory, antiviral, and hepatoprotective effects. We investigated the antitumor activities of berberine and matrine against human cervical cancer HeLa and SiHa cells using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, along with flow cytometry and western blotting analyses, to assess the effect of the compounds on the cellular status and apoptosis- and cell cycle-related proteins. The 24 h half-maximal inhibitory concentrations (IC50) of berberine and matrine were 123.633 ± 4.278 µmol/L and 9.625 ± 0.245 mmol/L against HeLa cells and 105.067 ± 3.745 µmol/L and 8.50 ± 0.23 mmol/L against SiHa cells, respectively. Berberine plus matrine inhibited cancer cell growth and caused cell cycle arrest. We observed an increased stimulation of apoptosis, which was likely mediated by enhanced levels of caspase-3, caspase-9, and B-cell lymphoma 2 (Bcl-2)-associated X protein (Bax), as well as decreased Bcl-2 protein expression. Cell cycle arrest in the G1 phase was probably mediated by p21 upregulation and cyclin-dependent kinase (Cdk)-4, Cdk-6, and cyclin D1 suppression. Combination treatment with berberine and matrine effectively inhibited human cervical cancer cell proliferation, most likely by stimulating apoptosis and inducing cell cycle arrest.

Źródło:

Acta Poloniae Pharmaceutica - Drug Research; 2019, 76, 6; 1089-1097
0001-6837
2353-5288

Pojawia się w:

Acta Poloniae Pharmaceutica - Drug Research

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 38.

Tytuł:

Flotation and molecular dynamics simulation of muscovite with mixed anionic/cationic collectors

Autorzy:

Bai, Yang
Li, Caixia
An, Hongyun
Wang, Guoliang
Zhao, Xin
Zhang, Jinqi

Powiązania:

https://bibliotekanauki.pl/articles/110125.pdf

Data publikacji:

2020

Wydawca:

Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej

Tematy:

muscovite
mixed anionic/cationic collectors
flotation
molecular dynamics simulation

Opis:

In this study, three kinds of anionic collectors (sodium oleate (NaOl), sodium dodecyl sulfonate (SDS) and naphthenic acid (NA)) were used in combination with dodecylamine (DDA) to investigate the flotation behavior of muscovite under the action of different mixed anionic/cationic collectors, and their mechanisms for adsorption on the muscovite (001) Surface were clarified using molecular dynamics simulations. The flotation results indicated that different mixed anionic/cationic collectors could improve the recovery of muscovite to varying degrees, but the optimum molar ratio of anionic collectors to DDA and the optimum mixed collector dosage were different. Molecular dynamics simulations showed that the mixed anionic/cationic collectors could significantly increase the hydrophobicity of the muscovite, as evidenced by the decrease in the calculated water molecule density on the muscovite surface and the diffusion coefficient of water molecules at the solid/liquid interface. The interaction between the amino group and the polar group of anionic collectors reduced the electrostatic repulsion between DDA cations and theoretically increased the adsorption capacity of the mixed anionic/cationic collectors on the muscovite surface. Moreover, DDA/NA and DDA/NaOl could improve the calculated carbon atom density on the muscovite surface, which enhanced the hydrophobic association between nonpolar carbon chains, thus further achieving an enhanced flotation performance.

Źródło:

Physicochemical Problems of Mineral Processing; 2020, 56, 2; 313-324
1643-1049
2084-4735

Pojawia się w:

Physicochemical Problems of Mineral Processing

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 39.

Tytuł:

Secure Data Aggregation Mechanism based on Constrained Supervision for Wireless Sensor Network

Autorzy:

Wang, Yubo
Li, Liang
Ao, Chen
Zhang, Puning
Wang, Zheng
Zhao, Xinyang

Powiązania:

https://bibliotekanauki.pl/articles/226140.pdf

Data publikacji:

2019

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

Wireless Sensor Network
security data aggregation
trust management
constrained supervision

Opis:

The data aggregation process of wireless sensor networks faces serious security problems. In order to defend the internal attacks launched by captured nodes and ensure the reliability of data aggregation, a secure data aggregation mechanism based on constrained supervision is proposed for wireless sensor network, which uses the advanced LEACH clustering method to select cluster heads. Then the cluster heads supervise the behaviors of cluster members and evaluate the trust values of nodes according to the communication behavior, data quality and residual energy. Then the node with the highest trust value is selected as the supervisor node to audit the cluster head and reject nodes with low trust values. Results show that the proposed mechanism can effectively identify the unreliable nodes, guarantee the system security and prolong the network life time.

Źródło:

International Journal of Electronics and Telecommunications; 2019, 65, 2; 259-266
2300-1933

Pojawia się w:

International Journal of Electronics and Telecommunications

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 40.

Tytuł:

Prediction of moisture content uniformity using hyperspectral imaging technology during the drying of maize kernel

Autorzy:

Huang, M.
Zhao, W.
Wang, Q.
Zhang, M.
Zhu, Q.

Powiązania:

https://bibliotekanauki.pl/articles/24685.pdf

Data publikacji:

2015

Wydawca:

Polska Akademia Nauk. Instytut Agrofizyki PAN

Tematy:

prediction
moisture content
uniformity
hyperspectral imaging
drying
maize kernel

Opis:

Moisture content uniformity is one of critical parameters to evaluate the quality of dried products and the drying technique. The potential of the hyperspectral imaging technique for evaluating the moisture content uniformity of maize kernels during the drying process was investigated. Predicting models were established using the partial least squares regression method. Two methods, using the prediction value of moisture content to calculate the uniformity (indirect) and predicting the moisture content uniformity directly, were investigated. Better prediction results were achieved using the direct method (with correlation coefficients RP = 0.848 and root-mean-square error of prediction RMSEP = 2.73) than the indirect method (RP = 0.521 and RMSEP = 10.96). The hyperspectral imaging technique showed significant potential in evaluating moisture content uniformity of maize kernels during the drying process.

Źródło:

International Agrophysics; 2015, 29, 1
0236-8722

Pojawia się w:

International Agrophysics

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 41.

Tytuł:

Experimental study on triboelectrostatic beneficiation of wet fly ash using Microwave Heating

Autorzy:

Li, H.
Chen, Y.
Zhang, X.
Zhao, Y.
Tao, Y.
Li, C.
He, X.

Powiązania:

https://bibliotekanauki.pl/articles/110399.pdf

Data publikacji:

2016

Wydawca:

Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej

Tematy:

wet fly ash
triboelectrostatic beneficiation
microwave heating
efficiency

Opis:

Triboelectrostatic beneficiation, as a physical method, of fly ash cannot only meet the technical requirements of fly ash application but also recycle of an unburned carbon as a useful energy source. The aim of this study was to investigate the feasibility of improving efficiency of triboelectrostatic beneficiation of wet fly ash using microwave heating. The wet fly ash with different moisture contents had an average loss-on-ignition of 12.56%. The fly ash samples were heated in a microwave oven before the experiments. The experimental conditions were electric field voltage of 40 kV and air flux ranging from 12 to 30 m3/h. The influence of the microwave heating on the wet fly ash triboelectrostatic beneficiation was discussed under the conditions of different microwave intensity and irradiation time. The results indicated that the removal rate and recycle rate of the unburned carbon showed a significant increase performance as the wet fly ash was processed by the microwave heating which was attributed to changes of moisture contents and dielectric constants caused by the microwave heating. The feasibility had been verified according to the experimental study on fly ash with different moisture contents. It can be concluded that the microwave heating process was efficiently applied for the wet fly ash triboelectrostatic beneficiation.

Źródło:

Physicochemical Problems of Mineral Processing; 2016, 52, 1; 328-341
1643-1049
2084-4735

Pojawia się w:

Physicochemical Problems of Mineral Processing

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 42.

Tytuł:

Experimental Insight into the Catalytic Mechanism of MFe2O4 (M = Ni, Zn and Co) on the Thermal Decomposition of TKX-50

Autorzy:

Hou, Xiaoting
Zhang, Ming
Zhao, Fengqi
Yang, Yanjing
An, Ting
Li, Hui
Pan, Qing
Wang, Xiaohong
Zhang, Kun

Powiązania:

https://bibliotekanauki.pl/articles/27788010.pdf

Data publikacji:

2021

Wydawca:

Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego

Tematy:

bimetallic iron oxide
thermal decomposition
TKX-50
catalysis
mechanism

Opis:

Synthesized dihydroxylammonium 5,5’-bistetrazole-1,1’-diolate (TKX-50) owes its outstanding application prospects in the field of insensitive solid propellants not only to its high energetic performance but also to its low mechanical sensitivity. Based on the excellent catalytic activity of bimetallic iron oxides for the thermal decomposition of TKX-50, the catalytic mechanism of bimetallic iron oxides (NiFe2O4, ZnFe2O4 and CoFe2O4) for TKX-50 pyrolysis has been explored. For this study, the decomposition process of TKX-50, before and after mixing with the bimetallic iron oxides NiFe2O4, ZnFe2O4 and CoFe2O4 was monitored by in-situ FTIR and gas-phase MS-FTIR instruments. Of the different catalysts, ZnFe2O4 gave the best result for reducing the initial decomposition temperature of TKX-50. Additionally, the activation energy of functional group cleavage of TKX-50, before and after mixing with ZnFe2O4, was also calculated for mechanism analysis from the results of the in-situ FTIR measurements. The results showed that the condensate and the gas-phase decomposition products of TKX-50 remained unchanged after mixing with different catalysts, while the activation energy of tetrazole ring cleavage was significantly reduced. The results of this study will be helpful for the rational design of insensitive solid propellant formulations containing TKX-50, and for understanding the pyrolysis mechanisms of TKX-50 before and after mixing with the efficient catalyst ZnFe2O4.

Źródło:

Central European Journal of Energetic Materials; 2021, 18, 2; 223--244
1733-7178

Pojawia się w:

Central European Journal of Energetic Materials

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 43.

Tytuł:

Faeces As an Important Pollution Source of Airborne Pathogens in Traveling from Swine Farm

Autorzy:

Liangbin, Zhao
Wenjin, Zhang
Dongmei, Jiang
Lin, Bai
Xiaoxia, Hao

Powiązania:

https://bibliotekanauki.pl/articles/27315760.pdf

Data publikacji:

2023

Wydawca:

Politechnika Koszalińska. Wydawnictwo Uczelniane

Tematy:

air microorganism
16SrRNA high-throughput sequencing
manure
piggery
swine

Opis:

Airborne pathogens are the most important factor causing environmental issues on pig farms. Research on airborne swine-derived microbes has mainly concentrated on several specific microbes or pathogens. The present work was conducted to detect and identify the entire microbial community in piggery air and their dispersion by 16SrRNA sequencing. Fifteen faeces and eighty-four air samples were collected in swine barns and from different distances away from the barns, respectively. The results showed that the faeces and air share the most dominant bacteria. The top 10 genera belonged to Fimicutes, Proteobacteria and Bacteroidetes, and accounted for 54% and 76-84% of the total sequences. Moreover, great higher (P < 0.01) microbial diversity was detected in the faeces. This study indicated that a hygienic interval of 50 m should be set on swine farms to prevent the spreading infectious disease caused by airborne pathogens.

Źródło:

Rocznik Ochrona Środowiska; 2023, 25; 55--67
1506-218X

Pojawia się w:

Rocznik Ochrona Środowiska

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 44.

Tytuł:

Colloidal crystal cladded microfiber for refractive index sensing

Autorzy:

Yan, H. T.
Zhao, X Y
Zhang, Ch.
Zhen, Z Q
Li, Q Z
Cao, J X
Xia, L X

Powiązania:

https://bibliotekanauki.pl/articles/174902.pdf

Data publikacji:

2014

Wydawca:

Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej

Tematy:

microfibers
colloidal crystals
refractive index sensing

Opis:

We investigate the evanescent field of a microfiber wrapped by colloidal crystals. The microfiber has the diameter of about 1 μm that is drawn from a single-mode fiber with an alcohol lamp. The colloidal spheres are further attached to the microfiber through thermal evaporation, then they self-assemble to crystal-like structures. The 400 nm, 590 nm, and 710 nm-diameter SiO2 colloidal spheres are used, respectively. The spectral responses are studied theoretically and experimentally, and the results agree with each other. It is revealed that the evanescent field of a microfiber could be modulated by the photonic band-gap of colloidal crystals. This characteristic is very useful in refractive index sensing for liquids.

Źródło:

Optica Applicata; 2014, 44, 2; 309-315
0078-5466
1899-7015

Pojawia się w:

Optica Applicata

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 45.

Tytuł:

Study on mechanical characteristics of rock type I fracture and anchorage strengthening mechanism

Autorzy:

Zhang, Wei
Zhao, Tongbin
Guo, Weiyao
Xing, Minglu

Powiązania:

https://bibliotekanauki.pl/articles/2104761.pdf

Data publikacji:

2022

Wydawca:

Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej

Tematy:

anchor rock
fracture type of I
fracture toughness
three-point bending test
toughening

Opis:

Engineering rocks are easily affected by excavation unloading and are in uniaxial compres- sion or tension, forming a typical I-type tension crack. Anchor rods are often used for on-site support to ensure safety and reliability of the project. The study of propagation and pen- etration of type I tension cracks and quantitative evaluation of rock anchoring effects are of great significance for exploring mechanical properties of rock fracture and revealing the mechanism of rock failure. In this paper, combined with speckle light measurement, a rock fracture toughness test of different anchoring positions and pre-tightening forces is carried out, the deformation evolution law of the crack tip and the fracture mechanics characteris- tics of the anchored rock are obtained, and the anchoring strengthening mechanism of the rock is discussed based on the theory of the net stress intensity factor. The research shows that the rock fracture process is divided into four stages: elastic deformation, steady crack propagation, crack instability propagation and residual deformation. After anchoring, the time of crack instability growth can be prolonged by 172% and the final residual deformation can be increased by 148%. Compared with the unanchored rock, the fracture toughness of rock initiation and instability increased by 83% and 124% respectively, and increased with growth of the pre-tightening force, which shows that the bolt increases the critical value of rock initiation and instability to achieve the toughening effect. After the rock is anchored, the time required for the crack to propagate to the same length increases by 55%, and the lateral deformation area is reduced by 46%, indicating that the lateral closing force of the bolt inhibits crack propagation and delays the instability of the rock matrix.

Źródło:

Journal of Theoretical and Applied Mechanics; 2022, 60, 3; 423--434
1429-2955

Pojawia się w:

Journal of Theoretical and Applied Mechanics

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 46.

Tytuł:

Optimization of CNTs and SiO2 for thermostability and mechanical properties of PF microcapsules : used for self-healing of closed wall cracks in goaf

Autorzy:

Fu, Mingming
Ma, Boyu
Zhang, Yuanping
Jia, Xinlei
Chen, Lu
Zhang, Yuping
Sun, Kaidi
Zhao, Guanning
Wang, Mengyao

Powiązania:

https://bibliotekanauki.pl/articles/24085883.pdf

Data publikacji:

2023

Wydawca:

Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej

Tematy:

PF microcapsule
crack repair
closed wall
nanomaterials
heat resistance
brittleness

Opis:

Air leakage of closed wall in coal mine goaf would cause spontaneous combustion of remained coal. Most of measures to repair cracks are carried out after cracks are penetrated, which is not conducive to early prevention of spontaneous combustion. Repairing damage at the initial stage of cracking makes prevention effect to the best. Phenol-formaldehyde resin (PF) microcapsules embedded in closed wall to achieve self-healing of initial cracks, but the actual repair effect is often less than expected. PF microcapsules (PFM) of carbon nanotubes (CNTs) and silicon dioxide (SiO2) decorated shell for self-healing of closed wall cracks were prepared by in-situ polymerization. The effects of nanomaterials on morphology, chemical constitution, thermal performance and mechanical properties of PF microcapsules were characterized by scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and nanoindentation test. The test results indicated that nanomaterials were successfully introduced into the shell of PF microcapsules. The CNTs-SiO2@PF microcapsules were uniformly dispersed, the thermal decomposition was delayed, and the residual carbon was significantly increased, and the brittleness of PF microcapsules was significantly enhanced. The 0.2CNTs-SiO2@PF microcapsules (0.2CNTs-SiO2@PFM) had a uniform and full particle size, the initial decomposition temperature was 267.6℃, the residual mass was 41.3%, the maximum load on the capsule wall reached 94.79 mN, and the load dropped sharply after the capsule wall rupture. Finally, the self-healing mechanism of closed wall doped with microcapsules was discussed. The exploration of modified phenolic microcapsules provides a new idea for the repair of closed wall in goaf.

Źródło:

Physicochemical Problems of Mineral Processing; 2023, 59, 3; art. no. 170020
1643-1049
2084-4735

Pojawia się w:

Physicochemical Problems of Mineral Processing

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 47.

Tytuł:

The cavitation nuclei transient characteristics of Lennard-Jones fluid in cavitation inception

Autorzy:

Fu, Q.
Zhang, B.
Zhao, Y.
Zhu, R.
Liu, G.
Li, M.

Powiązania:

https://bibliotekanauki.pl/articles/259255.pdf

Data publikacji:

2018

Wydawca:

Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa

Tematy:

cavitation nuclei
molecular dynamics simulation
Lennard-Jones fluid
cavitation inception
nucleation

Opis:

In the field of ocean engineering, cavitation is widespread, for the study of cavitation nuclei transient characteristics in cavitation inception, we applied theoretical analysis and molecular dynamics (MD) simulation to study Lennard-Jones (L-J) fluid with different initial cavitation nuclei under the NVT-constant ensemble in this manuscript. The results showed that in cavitation inception, due to the decrease of liquid local pressure, the liquid molecules would enter the cavitation nuclei, which contributed to the growth of cavitation nuclei. By using molecular potential energy, it was found that the molecular potential energy was higher in cavitation nuclei part, while the liquid molecular potential energy changes greatly at the beginning of the cavitation nuclei growth. The density of the liquid and the surface layer changes more obvious, but density of vapor in the bubble changes inconspicuously. With the growth of cavitation nuclei, the RDF peak intensity increased, the peak width narrowed and the first valley moved inner. When cavitation nuclei initial size reduced, the peak intensity reduced, the corresponding rbin increased. With the decrease of the initial cavitation nuclei, the system pressure and total energy achieved a balance longer, and correspondingly, they were smaller. In addition, at the beginning of the cavitation nuclei growth, the total energy and system pressure changed greatly.

Źródło:

Polish Maritime Research; 2018, S 2; 75-84
1233-2585

Pojawia się w:

Polish Maritime Research

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 48.

Tytuł:

Fluidization characteristics and separation performance of mild-hot gas-solid fluidized bed

Autorzy:

Lv, Bo
Luo, Zhenfu
Zhang, Bo
Zhao, Yuemin
Qin, Yunfei

Powiązania:

https://bibliotekanauki.pl/articles/109724.pdf

Data publikacji:

2019

Wydawca:

Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej

Tematy:

dry coal separation
mild-hot gas-solid fluidized bed
bed temperature
fluidization characteristics

Opis:

In recent years, the mild-hot gas-solid fluidized bed had a crucial influence on wet-in-feed sorting when it comes to moist feed (e.g., lignite) because of its expanding sorting range. To explain the favorable sorting effect of the mild-hot gas-solid fluidized bed, the fluidization characteristics (e.g., the pressure drop, density, etc.) was studied under different work conditions. In addition, a high-speed dynamic camera was used in this study to compare the slumping behavior of the magnetite slag at different temperatures. The optimum conditions for coal separation was also studied by Design-Expert software. It was shown that the bed temperature of the fluidized bed has a particular effect on its stability when the bed temperature was below 120 °C, which had a great influence on the separation. Finally, the probable deviation E of the mild-hot gas-solid fluidized bed under optimum operation conditions could be as low as 0.09 g/cm3 which showed the good separation ability.

Źródło:

Physicochemical Problems of Mineral Processing; 2019, 55, 1; 184-195
1643-1049
2084-4735

Pojawia się w:

Physicochemical Problems of Mineral Processing

Dostawca treści:

Biblioteka Nauki

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Skocz do pozycji: 49.

Tytuł:

Defect recognition of buried pipeline based on approximate entropy and variational mode decomposition

Autorzy:

Ju, Haiyang
Wang, Xinhua
Zhang, Tao
Zhao, Yizhen
Ullah, Zia

Powiązania:

https://bibliotekanauki.pl/articles/221572.pdf

Data publikacji:

2019

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

Buried Pipeline
Defect Recognition
Geomagnetic Anomaly Detection
Variational Mode Decomposition
Approximate Entropy

Opis:

The study aimed to examine the use of Geomagnetic Anomaly Detection (GAD) to locate the buried ferromagnetic pipeline defects without exposing them. However, the accuracy of GAD is limited by the background noise. In the present work, we propose an approximate entropy noise suppression (AENS) method based on Variational Mode Decomposition (VMD) for detection of pipeline defects. The proposed method is capable of reconstructing the magnetic field signals and extracting weak anomaly signals that are submerged in the background noise, which was employed to construct an effective detector of anomalous signals. The internal parameters of VMD were optimized by the Scale–Space algorithm, and their anti-noise performance was compared. The results show that the proposed method can remove the background noise in high-noise background geomagnetic field environments. Experiments were carried out in our laboratory and evaluation results of inspection data were analysed; the feasibility of GAD is validated when used in the application to detection of buried pipeline defects.

Źródło:

Metrology and Measurement Systems; 2019, 26, 4; 739-755
0860-8229

Pojawia się w:

Metrology and Measurement Systems

Dostawca treści:

Biblioteka Nauki

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Skocz do pozycji: 50.

Tytuł:

Research on electric vehicle charging load prediction and charging mode optimization

Autorzy:

Zhang, Zhiyan
Shi, Hang
Zhu, Ruihong
Zhao, Hongfei
Zhu, Yingjie

Powiązania:

https://bibliotekanauki.pl/articles/1841299.pdf

Data publikacji:

2021

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

electric vehicles
Monte Carlo
wavelet neural network
charging load
pojazdy elektryczne
sieć neuronowa falkowa

Opis:

To reduce the influence of the disorderly charging of electric vehicles (EVs) on the grid load, the EV charging load and charging mode are studied in this paper. First, the distribution of EV charging capacity and state of charge (SOC) feature quantity are analyzed, and their probability density function is solved. It is verified that both EV charging capacity and SOC obey the skew-normal distribution. Second, considering the space-time distribution characteristics of the EV charging load, a method for charging load prediction based on a wavelet neural network is proposed, and compared with the traditional BP neural network, the prediction results show that the error of the wavelet neural network is smaller, and the effectiveness of the wavelet neural network prediction is verified. The optimization objective function with the lowest user costs is established, and the constraint conditions are determined, so the orderly charging behavior is simulated by the Monte Carlo method. Finally, the influence of charging mode optimization on power grid operation is analyzed, and the result shows that the effectiveness of the charging optimization model is verified.

Źródło:

Archives of Electrical Engineering; 2021, 70, 2; 399-414
1427-4221
2300-2506

Pojawia się w:

Archives of Electrical Engineering

Dostawca treści:

Biblioteka Nauki

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