检索结果-南通市图书馆

APPLICATION OF PARAMETRIC DERIVATION METHOD TO THE CALCULATION OF PEIERLS ENERGY AND PEIERLS STRESS IN LATTICE THEORY

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2007年第4期20卷 363-368页

作者： xiaozhi wu shaofeng wang Institute for Structure and Function Chongqing University Chongqing 400044 China

Applying the parametric derivation method, Peierls energy and Peierls stress are calculated with a non-sinusoidal force law in the lattice theory, while the results obtained by the power-series expansion according to sinusoidal law can be deduced as a limiting case of non- sinusoidal law. The simplified expressions of Peierls energy and Peierls stress are obtained for the limit of wide and narrow. Peierls energy and Peierls stress decrease monotonically with the factor of modification of force law. Present results can be used expediently for prediction of the correct order of magnitude of Peierls stress for materials.

关键词： Peierls energy Peierls stress parametric derivation method lattice theory

EXTENDED CORE STRUCTURE OF DISSOCIATED EDGE DISLOCATIONS IN FCC CRYSTALS WITH CONSIDERATION OF DISCRETENESS

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2008年第5期21卷 403-410页

作者： xiaozhi wu shaofeng wang Huili Zhang Institute for Structure and Function Chongqing University Chongqing 400044 China

The extended core structure of the dissociated edge dislocation in Al, Au, Ag, Cu and Ni is determined within lattice theory of dislocation. The 2D dislocation equation governing the displacements is coupled by the restoring forces that are determined by the parameterization of the generalized stacking fault energies. The Ritz variational method is presented to solve the dislocation equation and the trial solution is constituted by two arctan-type functions with two undetermined parameters. The core widths of partial dislocations are wider than that obtained in generalized Peierls-Nabarro model due to the consideration of discreteness of crystal.

关键词： core structure dissociation dislocation equation variational method

ON CORE STRUCTURE PROPERTIES AND PEIERLS STRESS OF DISSOCIATED SUPERDISLOCATIONS IN ALUMINIDES:NiAl AND FeAl

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2010年第3期23卷 213-219页

作者： xiaozhi wu shaofeng wang Congbo Li Institute .for Structure and Function Chongqing University Chongqing 400044 China State Key Laboratory of Mechanical Transmission Chongqing University Chongqing 400044 China

The study of dislocation properties in B2 structure intermetallics NiAl and FeAl is crucial to understand their mechanical behaviors. In this paper, the core structure and Peierls stress of collinear dissociated （111）{110} edge superdislocations in NiAl and FeAl are investigated with the modified P-N dislocation equation. The generalized stacking fault energy curve along （111） direction in {110} slip plane contains two modification factors that can assure the antiphase energy and the unstable stacking fault energy to change independently. The results show that the core width of superpartials decreases with the increasing unstable stacking fault energy, and increases with the increasing antiphase boundary energy. The calculated Peierls stress of （111）{ 110） edge superdislocations in NiAl and FeAl are 475 MPa and 3042 MPa, respectively. The values of Peierls stress in NiAl is in accordance in magnitude with the experimental and the molecular statics simulations results.

关键词： core structure Peierls stress NiAl FeAl

New advances in the assessment of tight oil resource in China

在线全文

学校读者我要写书评

暂无评论

Petroleum Research 2017年第1期2卷 1-12页

作者： Shejiao wang Yuanjiang Yu Qiulin Guo Shaoyong wang xiaozhi wu PetroChina Research Institute of Petroleum Exploration and Development Beijing 100083China

The research on tight oil becomes another hotspot in the field of unconventional oil and gas after the boom of shale *** global recoverable resources of tight oil are estimated to be around 47.3×10^(9)*** recent years,significant progress has been made in the technologies of tight oil exploration and development in North America,thus stimulating the dramatic increase of tight oil ***,China has also acquired remarkable achievements in tight oil *** assessment methods have been established for tight oil resources by the US,generally dominated by analogy and statistical methods with their own advantages and disadvantages as well as applicable *** China,improvement of resource evaluation techniques becomes an urgent issue in increasing tight oil reserve and *** study mainly discusses the resource evaluation methods and resource enrichment characteristics of tight *** kinds of assessment methods in three categories(i.e.,analogy,statistical and genetic method)and evaluation parameters have been preliminary established,and are specifically applied in the Sichuan,Ordos,Songliao,Junggar,Bohai Bay and other tight oil basins through the newly hierarchical resource abundance analogy method,the estimated ultimate recovery(EUR)analogy method and the small-cell volumetric *** preliminary evaluation results reveal that China has great potential in tight oil resource,and the geological resources amount to 20×10^(9)t,providing a resource base for large-scale development.

关键词： Unconventional oil and gas Resource assessment method Resource potential Resource enrichment characteristics Tight oil

Simultaneously enhanced energy storage performance and luminance resistance in (K_(0.5)Na_(0.5))NbO_(3) -based ceramics via synergistic optimization strategy

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Advanced Ceramics 2024年第1期13卷 34-43页

作者： Yu Huan Diyu Gui Changxiao Li Tao Wei Lingzhi wu Xinjian wang xiaozhi wang Zhenxiang Cheng School of Materials Science and Engineering University of JinanJinan 250022China Yangtze Delta Region Transformation Center for Advanced Technological Achievements Suzhou 215000China Electronic Materials Research Laboratory Key Laboratory of the Ministry of Education and International Center for Dielectric ResearchXi’an Jiaotong UniversityXi’an 710032China Institute for Superconducting and Electronic Materials Australian Institute for Innovative MaterialsUniversity of WollongongInnovation CampusNorth Wollongong 2500Australia

The rapidly advancing energy storage performance of dielectric ceramics capacitors has garnered significant interest for applications in fast charge/discharge and high-power electronic *** the exceptional electrical properties in harsh environments can further promote their practical *** carriers can be excited under luminance irradiation,thereby leading to degradation of energy storage ***,a synergic optimization strategy is proposed to enhance energy storage properties and luminance resistance of(K_(0.5)Na_(0.5))NbO_(3)-base(KNN)***,the introduction of Bi(Zn0.5Ti0.5)O_(3) solid solution and La3+ions disrupts the long-range polar orders and enhances super paraelectric relaxation ***,doping La3+ions can increase the band gap and reduce oxygen vacancy concentration,resulting in excellent luminance ***,the viscous polymer process is employed to suppress the grain growth and promote chemical *** a result,ultrahigh recoverable energy storage density(Wrec)of 8.11 J/cm3 and high efficiency(η)of 80.98%are achieved under an electric field of 568 kV/***,the variations in Wrec andηare only 12.45%and 1.75%,respectively,under 500 W xenon lamp irradiation compared to the performance under a dark *** findings hold great potential in facilitating the practical application of dielectric ceramic capacitors in luminance irradiation environments.

关键词： potassium-sodium niobate energy storage performance illumination resistance oxygen vacancy viscous polymer processing

STOCHASTIC ELASTO-PLASTIC FRACTURE ANALYSIS OF ALUMINUM FOAMS

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2009年第3期22卷 276-282页

作者： Shiyong Sun Haoran Chen xiaozhi Hu Zhanjun wu State Key Laboratory of Structural Analysis for Industrial Equipment Dalian University of Technology Dalian 116024 China School of Mechanical Engineering The University of Western Australia Perth WA 6009 Australia

Model I quasi-static nonlinear fracture of aluminum foams is analyzed by considering the effect of microscopic heterogeneity. Firstly, a continuum constitutive model is adopted to account for the plastic compressibility of the metallic foams. The yield strain modeled by a two- parameter Weibull-type function is adopted in the constitutive model. Then, a modified cohesive zone model is established to characterize the fracture behavior of aluminum foams with a cohesive zone ahead of the initial crack. The tensile traction versus local crack opening displacement relation is employed to describe the softening characteristics of the material. And a Weibull statistical model for peak bridging stress within the fracture process zone is used for considering microscopic heterogeneity of aluminum foams. Lastly, the influence of stochastic parameters on the curve of stress-strain is given. Numerical examples are given to illustrate the numerical model presented in this paper and the effects of Weibull parameters and material properties on J-integral are discussed.

关键词： aluminum foams cohesive zone model continuum constitutive model fracture Weibull distributions J-integral

Analysis of one dimensional and two dimensional fuzzy controllers

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2006年第2期17卷 362-373页

作者： Ban Xiaojun Gao xiaozhi Huang Xianlin wu Tianbao Dept. of Control Theory and Engineering Harbin Inst. of Technology Harbin 150001 P. R. China Inst. of Intelligent Power Electronics Helsinki Univ. of Technology Espoo Finland

The analytical structures and the corresponding mathematical properties of the one dimensional and two dimensional fuzzy controllers are first investigated in detail. The nature of these two kinds of fuzzy controllers is next probed from the perspective of control engineering. For the one dimensional fuzzy controller, it is concluded that this controller is a combination of a saturation element and a nonlinear proportional controller, and the system that employs the one dimensional fuzzy controller is the combination of an open-loop control system and a closedloop control system. For the latter case, it is concluded that it is a hybrid controller, which comprises the saturation part, zero-output part, nonlinear derivative part, nonlinear proportional part, as well as nonlinear proportional-derivative part, and the two dimensional fuzzy controller-based control system is a loop-varying system with varying number of control loops.

关键词： one dimensional fuzzy controller two dimensional fuzzy controller analytical structures fuzzy inference control system analysis.

CC-chemokine receptor 7 and its ligand CCL 19 promote mitral valve interstitial cell migration and repair

在线全文

学校读者我要写书评

暂无评论

The Journal of Biomedical Research 2015年第6期29卷 456-464页

作者： xiaozhi wang Liang wang Liping Miao Rong Zhao Yanhu wu Xiangqing Kong Department of Cardiology The First Affiliated Hospital of Nanjing Medical University Department of Cardiothoracic Surgery The First Affiliated Hospital of Nanjing Medical University

The effect of CC-chemokine receptor 7 （CCR7） and CC-chemokine ligand 19 （CCL19） on rheumatic mitral ste- nosis is unknown. This study aimed to explore the roles of CCR7 and CCL19 in rheumatic mitral stenosis by mea- suring the expression of CCR7 and CCL19 in human mitral valves from rheumatic mitral stenosis patients. Additionally, we examined their effects on human mitral valve interstitial cells （hMVICs） proliferation, apoptosis and wound repair. CCR7 and CCL19 expression was measured in the mitral valves from rheumatic mitral stenosis patients （n= 10） and compared to normal mitral valves （n=5）. CCR7 was measured in cultured hMVICs from rheu- matic mitral stenosis patients and normal donors by RT-PCR and immunofluorescence. The cells were also treated with exogenous CCL19, and the effects on wound healing, proliferation and apoptosis were assayed. In the rheu- matic mitral valves, valve interstitial cells expressed CCR7, while mononuclear cells and the endothelium expressed CCL19. Healthy mitral valves did not stain positive for CCR7 or CCL19. CCR7 was also detected in cultured rheu- matic hMVICs or in normal hMVICs treated with CCL19. In a wound healing experiment, wound closure rates of both rheumatic and normal hMVICs were significantly accelerated by CCL19. These effects were abrogated by a CCR7 neutralizing antibody. The CCR7/CCL19 axis did not influence the proliferation or apoptosis of hMVICs, indicating that wound healing was due to increased migration rates rather than increased proliferation. In conclu- sion, CCR7 and CCL19 were expressed in rheumatic mitral valves. The CCR7/CCL19 axis may regulate remodel- ing of rheumatic valve injury through promoting migratory ability of hMVICs.

关键词： CC-chemokine receptor 7 CC-chemokine ligand 19 rheumatic mitral stenosis migration woundrepair

Enhanced photocatalytic performance of Bi_(2)O_(2)CO_(3)/Bi_(4)O_(5)Br_(2)/reduced graphene oxide Z-schemehe terojunction via a one-pot room-temperature synthesis

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第4期138卷 418-427页

作者： Xiaoge wu Lei Yan Rongrong Qin Qikai Zhang Wei Yang xiaozhi wang Yongcai Zhang Min Luo Jianhua Hou College of Environmental Science and Engineering Yangzhou UniversityYangzhouJiangsu 225009China Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization Nanjing 210095China Beijing Xinfeng Aerospace Equipment Co. Ltd.Beijing 100854China Beijing System Design Institute of Electro-Mechanic Engineering Beijing 100005China College of Chemistry and Chemical Engineering Ningxia UniversityYinchuanNingxia 750021China

Bi_(2)O_(2)CO_(3)(BOC)/Bi_(4)O_5Br_(2)(BOB)/reduced graphene oxide(rGO)Z-scheme heterojunction with promising photocatalytic properties was synthesized via a facile one-pot room-temperature ***-thin nanosheets of BOC and BOB were grown in situ on r *** formed 2D/2D direct Z-scheme heterojunction of BOC/BOB with oxygen vacancies(OVs)effectively leads to lower negative electron reduction potential of BOB as well as higher positive hole oxidation potential of BOC,showing improved reduction/oxidation ***,rGO is an acceptor of the electrons from the conduction band of *** dual roles significantly improve the transfer performance of photo-induced charge carriers and accelerate their *** layered nanosheet structure,rich OVs,high specific surface area,and increased utilization efficiency of visible light,the multiple synergistic effects of BOC/BOB/rGO can achieve effective generation and separation of the electron-holes,thereby generating more·O_(2)^(-)and h^(+).The photocatalytic reduction efficiency of CO_(2)to CO(12.91μmol/(g·hr))is three times higher than that of BOC(4.18μmol/(g·hr)).Moreover,it also achieved almost 100%removal of Rhodamine B and cyanobacterial cells within 2 hours.

关键词： Bi_(2)O_(2)CO_(3) Bi_(4)O_(5)Br_(2) Reduced graphene oxide Z-scheme heterojunction Photocatalysis CO_(2)reduction