检索结果-南通市图书馆

A mathematical model for solid liquid and mass transfer coupling and numerical simulation for hydraulic fracture in rock salt

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2005年第8期15卷 742-748页

作者： LIANG Weiguo 1,2. and ZHAO Yangsheng1(1. Mining technology institute, Taiyuan {2. of technology, Taiyuan 03002., china 2. Rock and Soil Mechanics institute, Chinese Academy of Sciences, wuhan 430071, china) Mining technology institute Taiyuan University of Technology Taiyuan 030024 China. Rock and Soil Mechanics institute Chinese Academy of Sciences Wuhan 43007! China

The hydraulic fracture in rock salt is a complicated solid fluid and mass transfer coupling process. Through theoretical analysis, a solid fluid and mass transfer coupling mathematical model of hydraulic fracture in rock salt is established in this work, and numerical simulations are carried out with the model. The simulation results indicate that rock salt cracks in the typical way of wing-crack(or tensile crack) during the fracture, and the relation of fracture aperture (w) with expanding distance (x) and fracture time (t) is w=(0.0034+0.0006t)e (0.0007+0.0018t)x. Furthermore, it has been found that both the water pressure in the crack and the expanding velocity of the crack decrease gradually as a result of the influence of salt dissolving during fracturing. These numerical simulations well illustrate the process of hydraulic fracture in rock salt and are significantly meaningful in engineering practice.

关键词： rock salt hydraulic fracture solid liquid and mass transfer coupling mathematical model numerical simulation.

Exact eigenstates for a class of models describing multiphoton processes in the presence of seven bosonic modes

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china(Physics,Mechanics & Astronomy) 2004年第6期47卷 649-657页

作者： ZHAN Zhiming1,LI Weibin2.YOU Jun2.XIE Xiaotao2.& YANG Wenxing2.1.State Key Laboratory of laser technology,{2. university of Science and technology,wuhan 43.074,china 2.Department of Physics,{2. university of Science and technology,wuhan 43.074,china 1. State Key Laboratory of laser technology Huazhong University of Science and Technology 430074 Wuhan China 2. Department of Physics Huazhong University of Science and Technology 430074 Wuhan China

We present the analytical expressions of eigenstates and eigenenergies by using a parameter λ without the assumption of Bethe anzatz for three kinds of seven-bosonic-mode mixing models. The parameter is shown to be determined by the roots of a simple polynomial. We also demonstrate the exact analytical expressions of eigenstates and energies without any unknown parameter.

关键词： spectra, eigenstate, eigenvalue.

Structure and Magnetic Properties of Ni-doped ZnO Powder

在线全文

学校读者我要写书评

暂无评论

Journal of wuhan university of {2.(Materials Science) 2010年第5期25卷 770-773页

作者：高放赵俊 Department of Electronic Science and technology Huazhong University of Science and Technology

Ni-doped ZnO nanopowder （Zn0.98Ni0.2.） was synthesized by improved coprecipitation method. The average particle size of the powder was estimated to be 50 nm. The powder was then processed by thermal treatment. Samples were annealed at 1 073, 1 2.3, and 1 473 K, respectively. The solubility of NiO in ZnO and the lattice parameters of ZnO both increased with the temperature. The magnetic property of the doped samples was examined, and hysteresis loops were got. The results showed all the samples were ferromagnetic, while powder processed at 1 2.3 K for 4 h got a highest saturation magnetization （Ms） of 0.0457 emu/g. Also, magnetic properties were related to the grain size of the powder.

关键词： ferromagnetism diluted magnetic semiconductor Ni-doped ZnO coprecipitation solid state reaction

A novel DNA computing model based on RecA-mediated triple-stranded DNA structure

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2007年第6期17卷 708-711页

作者： Fang Gang1, Zhang Shemin2. Dong Yafei1 and Xu Jin1(1. The Key Laboratory of Image Processing and Intelligent Control, Department of Control Science & engineering, huazhong {2. of Science and technology, wuhan 43.074, china 2. Shaanxi {2. of technology, Hanzhong 72.000, china) [a]The Key Laboratory of Image Processing and Intelligent Control Department of Control Science & Engineering Huazhong University of Science and Technology Wuhan China [b]Shaanxi university of technology Hanzhong China

The field of DNA computing emerged in 1994 after Adleman’s paper was published. Henceforth,a few scholars solved some noted NP-complete problems in this way. And all these methods of DNA computing are based on conventional Watson-Crick hydrogen bond of doublehelical DNA molecule. In this paper, we show that the triple-stranded DNA structure mediated by RecA protein can be used for solving computational problems. Sequence-specific recognition of double-stranded DNA by oligonucleotide-directed triple helix (triplex) formation is used to carry out the algorithm. We present procedure for the 3-vertex-colorability problems. In our proposed procedure, it is suggested that it is possible to solve more complicated problems with more variables by this model.

关键词： DNA computing 3-vertex-colorability problem.

On three-dimensional geological modeling and visualization

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china Earth Sciences 2004年第8期47卷 739-748页

作者： WU Qiang1 & XU Hua2.1. Department of Resource Exploitation engineering, china {2. of Mining and technology, Beijing 100083, china 2. Beijing institute of Petrochemical technology, Beijing 102.17, china 1. Department of Resource Exploitation engineering China University of Mining and Technology 100083 Beijing China 2. Beijing institute of Petrochemical technology 102617 Beijing China

The technology of 3D geological modeling will bring about great changes in the methods of geological data acquiring, storing, processing and displaying. However, no perfect or convenient software systems have been developed up to now since the geologic data which re-flect geological entities bear the feature of diversity, uncertainty and complexity. Some supervoxel models, mathematical models of fault and geometrical models of fold have been contrived so as to show the space geometric configuration of the complicated geologic structures. The application-oriented system architecture for 3D geological modeling is established; and a novel design concept based on spatial data processing is also proposed with the technology of solid modeling as its core and the application of models as its objective. Theories and methods for 3D geological modeling will hopefully be enriched and developed. In the light of these theories and methods, a feature-based navigation visualization technique is also put forward in the paper. By integrating geo-database, graphics libraries and KBS with 3D dynamic simulation systems, geologists will be able to capture the partial characteristics and whole structure embodied in the geological data in a direct-viewing, figurative and accurate manner.

关键词： 3D geological modeling,geometrical model,system architecture,visualization

Preparation and Characterization of Chitosan/Carboxymethylated Konjac Glucomannan Blend Films

在线全文

学校读者我要写书评

暂无评论

wuhan university Journal of Natural Sciences 2002年第1期7卷 107-112页

作者： Zheng Hua 1 , Du Yu-min 2.1. Department of Chemical engineering, wuhan {2. of technology, wuhan 430070, Hubei, china 2. College of Chemistry and Molecular Sciences, wuhan {2., wuhan 430072. Hubei, china wuhan university of {2. Department of Chemical Engineering Wuhan Hubei China (GRID:grid.162110.5) (ISNI:***) wuhan university College of Chemistry and Molecular Sciences Wuhan Hubei China (GRID:grid.49470.3e) (ISNI:***)

In order to improve the mechanical and water swelling properties of the chitosan (CS) film, a series of transparent films were prepared by blending 2.(weight) chitosan acetic acid solution with 1.5%(weight) carboxymethylated konjac glucomannan (CMKGM) aqueous solution according to predetermined ratio and drying at 30°C. The morphological structure, miscibility, thermal stability, mechanical properies, and swelling capacity of the blend films were studied by infrared (IR), X-ray diffraction (XRD), differential thermal analysis (DTA), scanning electron micrograph (SEM), and measurements of the mechanical properties and swelling properties. The results demonstrated that there was strong interaction and good miscibility between CS and CMKGM resulted from intermolecular hydrogen bonding and electrostatic force. The mechanical properties in dry state and wet state, thermostability, and water swelling properties of the blend films were obviously improved. The best values of the tensile strength in the dry and wet state achieved 89 MPa and 49 MPa, respectively, when the CMKGM content was 30%(weight). The CS/ CMKGM blend films provided promising biomedical applications.

关键词： Key words chitosan carboxymethylated konjac glucomannan blend films structure characterization

Evolution of Bright Screening-photovoltaic Spatial Optical Solitons

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of lasers 2001年第5期10卷 28-33页

作者： LIU Jinsong (State Key Laboratory of laser technology, {2. university of Science and technology, wuhan 43.074, china) 华中科技大学激光技术国家重点实验室湖北武汉

A numerical analysis of the dynamical evolution of bright screening photovoltaic (SP) spatial solitons in biased photovoltaic photorefractive materials in the case of neglecting the material loss and the diffusion is presented. When an incident optical beam is a bright SP soliton, the beam propagates along a linear path with its shape kept unchanged. When the incident optical beam is slightly different from a bright SP soliton, the beam reshapes itself and tries to evolve into a bright SP soliton after a short distance. However, when the incident optical beam is significantly different from a SP bright soliton, the beam cannot evolve into a stable bright SP soliton, and tends to experience periodic compression and expansion. For a low intensity input beam, the wave experiences a periodic process of compression first and then expansion during the initial part of the cycle. For a high intensity input beam, however, the wave will initially diffract and then experiences compression during the cycle.

关键词： nonlinear optics spatial optical solitons photorefractive effects

Optimality strategy of a sealed-offer simultaneous bargaining protocol

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china(Information Sciences) 2011年第1期54卷 79-90页

作者： ZHANG LinLan1,2.CHEN XueGuang2.& HONG Liu2.1School of Business,Hubei university,wuhan 430062.{2. 2.3} of Systems engineering,huazhong university of Science and technology,wuhan 43.074,{2. 1. School of Business Hubei University Wuhan 430062 China2. Institute of Systems Engineering Huazhong University of Science and Technology Wuhan 430074 China

Alternating-offer bargaining protocol is the most predominant way for solving bilateral bargaining ***,alternating-offer may consume much time and cause a low effciency in some ***, a deadlock in which both negotiators are unwilling to concede or refuse to disclose more information may arise. Then mediation is *** paper presents an agent-based sealed-offer simultaneous bargaining protocol by introducing a nonbiased *** information of both agents is considered completely *** our agent-based model,both agents simultaneously submit their respective offers to the mediate *** offers of each agent are not revealed to the *** design can discourage counter-speculation and effectively control fraud and misrepresentation in a certain ***,we analyze how an agent can exploit the available information in selecting a strategy that maximizes its expected utility and give the optimal offers of each agent at each stage of the *** groups of automated experiments are conducted to evaluate the performance of the proposed automated negotiation procedure.

关键词： automated negotiation bargaining sealed-bid optimal strategy

A low frequency piezoelectric power harvester using a spiral-shaped bimorph

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china(Physics,Mechanics & Astronomy) 2006年第6期49卷 649-659页

作者： HU Yuantai1,2.HU Hongping2.& YANG Jiashi3 1. institute of Mechanics and Sensing technology,Central South {2.,Changsha 410083,china 2. Department of Mechanics,huazhong {2. of Science and technology,wuhan 43.074,china 3. Department of engineering Mechanics,{2. of Nebraska,Lincoln,NE 68588-052.,USA 1. institute of Mechanics and Sensing technology Central South University Changsha 410083 China 2. Department of Mechanics Huazhong University of Science and Technology Wuhan 430074 China 3. Department of engineering Mechanics University of Nebraska Lincoln NE 68588-0526 USA

We propose a spiral-shaped piezoelectric bimorph power harvester operating with coupled flexural and extensional vibration modes for applications to low frequency energy sources. A theoretical analysis is performed and the computational results show that the spiral structure has relatively low operating frequency compared to beam power harvesters of the same size. It is found that to optimize the performance of a piezoelectric spiral-shaped harvester careful design is needed.

关键词： spiral-shaped bimorph,piezoelectric harvester,power density.