检索结果-南通市图书馆

Elliptical inclusion in an anisotropic plane:non-uniform interface effects

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2022年第5期43卷 667-688页

作者： Pengyu PEI ming dai School of Electrical and Mechanical Engineering Jinling Institute of TechnologyNanjing 211169China State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and AstronauticsNanjing 210016China

We study the plane deformation of an elastic composite system made up of an anisotropic elliptical inclusion and an anisotropic foreign matrix surrounding the *** order to capture the influence of interface energy on the local elastic field as the size of the inclusion approaches the nanoscale,we refer to the Gurtin-Murdoch model of interface elasticity to describe the inclusion-matrix interface as an imaginary and extremely stiff but zero-thickness layer of a finite stretching *** opposed to isotropic cases in which the effects of interface elasticity are usually assumed to be uniform(described by a constant interface stretching modulus for the entire interface),the anisotropic case considered here necessitates non-uniform effects of interface elasticity(described by a non-constant interface stretching modulus),because the bulk surrounding the interface is *** this end,we treat the interface stretching modulus of the anisotropic composite system as a variable on the interface curve depending on the specific tangential direction of the *** then devise a unified analytic procedure to determine the full stress field in the inclusion and matrix,which is applicable to the arbitrary orientation and aspect ratio of the inclusion,an arbitrarily variable interface modulus,and an arbitrary uniform external loading applied *** non-uniform interface effects on the external loading-induced stress distribution near the interface are explored via a group of numerical *** is demonstrated that whether the nonuniformity of the interface effects has a significant effect on the stress field around the inclusion mainly depends on the direction of the external loading and the aspect ratio of the inclusion.

关键词： elliptical inclusion anisotropic material interface stress Gurtin-Murdoch model membrane-type interface

Application of material-mesh algebraic collapsing acceleration technique in method of characteristics——based neutron transport code

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2021年第8期32卷 95-109页

作者： ming dai Mao-Song Cheng Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China CAS Innovative Academies in TMSR Energy System Chinese Academy of SciencesShanghai 201800China

The algebraic collapsing acceleration(ACA)technique maximizes the use of geometric flexibility of the method of characteristics(MOC).The spatial grids for loworder ACA are the same as the high-order transport,which makes the numerical solution of ACA equations costly,especially for large-size *** speed-up the MOC transport iterations effectively for general geometry,a coarse-mesh ACA method that involves selectively merging fine-mesh cells with identical materials,called material-mesh ACA(MMACA),is *** energy group batching(EGB)strategy in the tracing process is proposed to increase the parallel efficiency for microscopic crosssection *** and macroscopic crosssection benchmark problems are used to validate and analyse the accuracy and efficiency of the MMACA *** maximum errors in the multiplication factor and pin power distributions are from the VERA-4 B-2 D case with silver-indium-cadmium(AIC)control rods inserted and are 104 pcm and 1.97%,*** with the single-thread ACA solution,the maximum speed-up ratio reached 25 on 12 CPU cores for microscopic cross-section VERA-4-2 D *** the C5 G7-2 D and LRA-2 D benchmarks,the MMACA method can reduce the computation time by approximately one *** present work proposes the MMACA method and demonstrates its ability to effectively accelerate MOC transport iterations.

关键词： Algebraic collapsing acceleration Material-mesh ACA Method of characteristics OpenMP Arbitrary geometry

The symmetry and loading-independency of multiple inclusions enclosing uniform stresses in an infinite elastic plane

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2020年第10期41卷 1493-1496页

作者： ming dai P.SCHIAVONE State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and AstronauticsNanjing 210016China Department of Mechanical Engineering University of AlbertaEdmontonAlberta T6G 1H9Canada

The identification of multiple interacting inclusions with uniform internal stresses in an infinite elastic matrix subjected to a uniform remote loading is of fundamental importance in the mechanics and design of particulate composite *** anti-plane shear and plane deformations,certain sufficient conditions have been established in the literature which guarantee uniform internal stresses inside multiple interacting inclusions displaying various symmetries when the matrix is subjected to specific uniform remote ***,sufficient conditions which allow for the design of multiple interacting inclusions independent of any specific form of(uniform)remote loading have also been *** this paper,we demonstrate rigorously that,in all cases,these sufficient conditions are also necessary conditions and indeed allow for the identification of all possible collections of such inclusions.

关键词： uniform stress Eshelby’s conjecture multiple inclusion

A distribution prior model for airplane segmentation without exact template

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2020年第1期31卷 56-63页

作者： dai ming ZHOU Zhiheng GUO Yongfan School of Electronics and Information Engineering South China University of Technology

In many practical applications of image segmentation problems,employing prior information can greatly improve segmentation *** paper continues to study one kind of prior information,called prior *** this research,there is no exact template of the object;instead only several samples are *** proposed method,called the parametric distribution prior model,extends our previous model by adding the training procedure to learn the prior distribution of the *** this paper establishes the energy function of the active contour model(ACM)with consideration of this parametric form of prior ***,during the process of segmenting,the template can update itself while the contour *** are performed on the airplane data *** results demonstrate the potential of the proposed method that with the information of prior distribution,the segmentation effect and speed can be both improved efficaciously.

关键词： image segmentation active contour model(ACM) prior distribution level set method

Parametric shape prior model used in image segmentation

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2016年第5期27卷 1115-1121页

作者： zhiheng zhou ming dai huiqiang zhong College of Electronics and Information Engineering South China University of Technology Guangzhou 510640 China

Due to the frequency of occlusion, cluttering and lowcontrast edges, gray intensity based active contour models oftenfail to segment meaningful objects. Prior shape information is usuallyutilized to segment desirable objects. A parametric shape priormodel is proposed. Firstly, principal component analysis is employedto train object shape and transformation is added to shaperepresentation. Then the energy function is constructed througha combination of shape prior energy, gray intensity energy andshape constraint energy of the kernel density function. The objectboundary extraction process is converted into the parameters solvingprocess of object shape. Besides, two new shape prior energyfunctions are defined when desirable objects are occluded by otherobjects or some parts of them are missing. Finally, an alternatingdecent iteration solving scheme is proposed for numerical *** on synthetic and real images demonstratethe robustness and accuracy of the proposed method.

关键词： image segmentation shape prior principal componentanalysis kernel density function.

A mini review of NiFe-based materials as highly active oxygen evolution reaction electrocatalysts

在线全文

学校读者我要写书评

暂无评论

Nano Research 2015年第1期8卷 23-39页

作者： ming Gong Hongjie dai Department of Chemistry Stanford University Stanford CA 9430S USA

Oxygen evolution reaction （OER） electrolysis, as an important reaction involved in water splitting and rechargeable metal-air batteries, has attracted increasing attention for clean energy generation and efficient energy storage. Nickel/iron （NiFe）-based compounds have been known as active OER catalysts since the last century, and renewed interest has been witnessed in recent years on developing advanced NiFe-based materials for better activity and stability. In this review, we present the early discovery and recent progress on NiFe-based OER electrocatalysts in terms of chemical properties, synthetic methodologies and catalytic performances. The advantages and disadvantages of each class of NiFe-based compounds are summarized, including NiFe alloys, electrodeposited films and layered double hydroxide nanoplates. Some mechanistic studies of the active phase of NiFe-based compounds are introduced and discussed to give insight into the nature of active catalytic sites, which could facilitate further improving NiFe based OER electrocatalysts. Finally, some applications of NiFe- based compounds for OER are described, including the development of an electrolyzer operating with a single AAA battery with voltage below 1.5 V and high performance rechargeable Zn-air batteries.

关键词： oxygen evolution reaction electrocatalysis nickel-iron water splitting

Microstructure and mechanical properties of friction stir welding joint during post weld heat treatment with different zigzag lines

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

Rare Metals 2019年第11期38卷 1070-1077页

作者： Zhi-Li Hu Qiu Pang ming-Liang dai Hubei Key Laboratory of Advanced Technology of Automobile Components Wuhan University of TechnologyWuhan 430070China Hubei Collaborative Innovation Center for Automotive Components Technology Wuhan University of TechnologyWuhan 430070China School of Mechanical and Electrical Engineering Wuhan Donghu UniversityWuhan 430212China

Zigzag line is a common defect in friction stir welding(FSW) *** formation mechanism of the zigzag line in Al-Cu alloy FSW joint and its influence on the microstructure and mechanical properties during post weld heat treatment(PWHT) were studied by scanning electron microscopy(SEM),microhardness and tensile *** is found that the occurrence of zigzag line for PWHT joint is determined by PWHT process which in nature depends on residual stress and thermal stress of FSW *** optimization of PWHT process to reduce the residual and thermal stress can trigger for the deterioration of mechanical properties of PWHT joints with zigzag *** obvious decrease of tensile properties is observed for T6-450 and T6-495 joints although zigzag line appears in the *** determines the sizes of zigzag line cracks and consequently determines the fracture location and characteristics of FSW joint.

关键词： Friction stir welding Post weld heat treatment Zigzag line Mechanical properties

Feature-based Design of Welded Structure for Robotic Arc Welding Off-line Programming

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2001年第1期17卷 181-182页

作者： Tong LIU Jinsong TIAN Lin WU ming dai National Key Lab of Advanced Welding Production Technology Harbin institute of TechnologyHarbin 150001China

Feature modeler of welded structure provides both 3D-geographical and non-geographical features for the off-line programming of arc welded robot. Welded structure is regarded as an assembly, the design of welded structure consists of three aspects f plane, joint, and groove design. Each aspect corresponds to a category of features. The plane features are defined by interactive feature definition. A method analogous to the 'mating feature' is introduced to represent the joint features. Based on AutoCAD 2000, a B-rep solid modeler, a prototype system is implemented.

关键词： Robotic Arc Welding welded structure prototype system

Local Area Quotas for Industrial Emissions along Reaches of the Pearl River in Guangdong

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Population,Resources and Environment 2008年第1期6卷 72-78页

作者： dai ming Qin Jian dai Xie＇er Research Centre for Regional and Urban Development Jinan University Guangzhou Guangdong 510632 China Faculty of Mathematics Sun Yat-sen University Guangzhou Guangdong 510275 China

There is an obvious departure from the regional equi-librium of developments between the upper and lower reaches of the Pearl River in Guangdong, which resulted in "the effects of contra-geography-grads development". It is mainly because the upriver mountainous areas have been deeply stuck in industriali-zation delay and marginalization plights, so that nearly 40 million local people have conceived a dream to get rid of "the vicious circle of poverty" by speeding up industrial development. But the problem is that such industrialization efforts on a large scale in mountainous areas are encountering the bottleneck of environ-mental capacity that strictly limits industrial emissions along the upper reaches of any water system. As a solution, an institutional arrangement called "the Local Area Quotas for Industrial Emis-sions along the Pearl River" is put forward supposed to give cor-responding compensation to the rights of industrial development yielded by some areas with lower environmental capacity through the distribution and trading of IDQs.

关键词： Pearl River regional developments in equilibrium industrial discharge quotas (IDQs) local area quotas (LAQs)