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A new orthogonality relationship for orthotropic thin plate theory and its variational principle

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Science china(Physics,Mechanics & Astronomy) 2005年第3期48卷 371-380页

作者： LUO Jianhui 1., LONG Yuqiu 2.& LIU Guangdong 1.1. College of Civil {1., Hunan university, Changsha 41.082.{2. 2. Department of Civil {1., Tsinghua university, Beijing 1.0084,{2. 1. College of Civil engineering Hunan University 410082 Changsha China 2. Department of Civil {1. Tsinghua University 100084 Beijing China

The thought how dual vectors are constructed in a new orthogonality relationship for theory of elasticity is generalized into orthotropic thin plate bending problems by using the analogy theory between plane elasticity problems and plate bending problems. Dual differential equations are directly obtained by using a mixed variables method. A dual differential matrix to be derived possesses a peculiarity of which principal diagonal sub-matrixes are zero matrixes. Two independently and symmetrically orthogonality sub-relationships are discovered. By using the integral form for elastic bending theory of orthotropic thin plate the orthogonality relationship is demonstrated. By selecting felicitous dual vectors a new orthogonality relationship for theory of elasticity can be generalized into elastic bending theory of orthotropic thin plate. By using the integral form a variational principle which is relative to differential form and a whole function expression are proposed.

关键词： theory of elasticity, thin plate theory, dual vectors, orthogonality relationship, orthotropic, variational principle.

Analysis on the long term discharge of a catchment

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Journal of Environmental Sciences 2000年第3期12卷 279-285页

作者： HONG Lin 1. TAKASE Keiji 2. SATO Koichi 2.(1. Wuhan university of Hydraulic and Electric engineering, Wuhan 430072.{2. 2. Ehime university, Japan) Wuhan university of Hydraulic and Electric {1. Wuhan 430072 China Ehime university Japan

In this study, the characteristics of the long term discharge of a Terraced Paddy Field Catchment are studied. 2.Kind of Tank Models are proposed and used to simulate the discharge of the catchment. The characteristics of the model simulations of the discharge of the catchment are analyzed and compared with those of a forest catchment.

关键词： long term discharge model simulation terraced paddy field catchment

Research on nonlinear constitutive relationship of permanent deformation in asphalt pavements

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Science china(Physics,Mechanics & Astronomy) 2006年第6期49卷 671-682页

作者： PENG Miaojuan1.& XU Zhihong2.1. Department of Civil {1.,Shanghai university,Shanghai 2.0072.{2. 2. School of Transportation {1.,Tongji university,Shanghai 2.0092.{2. 1. Department of Civil engineering Shanghai University Shanghai 200072 China 2. School of Transportation {1. Tongji University Shanghai 200092 China

To predict correctly the rut depths in asphalt pavements,a new nonlinear viscoelastic-elastoplastic constitutive model of permanent deformation in asphalt pave-ments is presented. The model combines a generalized Maxwell model with an elasto-plastic one. Then from the creep theory,the linear and nonlinear constitutive equations of the generalized Maxwell model are obtained. From the nonlinear finite element method for the rutting of the asphalt pavement,the rut depths of 4 asphalt-aggregate mixtures are obtained. And the results are compared with the ones from the finite element method by SHRP and the experiments by SWK/UN. The results in this paper are better than the ones by SHRP,and agree with the ones of the experiment by SWK/UN. This shows that the nonlinear viscoelastic-elastoplastic constitutive model,which is presented in this paper for the rutting of the asphalt pavement,is effective. The properties,such as nonlinear elastic-ity,plasticity,viscoelasticity and nonlinear viscoelasticity,which affect the rutting of an asphalt pavement,can be shown in the model. And the characteristics of the permanent deformation of the asphalt pavement can be presented entirely in the model.

关键词： asphalt pavement,permanent deformation,nonlinear viscoelastic-elastoplastic constitutive relationship,generalized Maxwell model,creep compliance.

Fracture analysis of a functionally graded interfacial zone between two dissimilar homogeneous materials

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Science china(Physics,Mechanics & Astronomy) 2006年第5期49卷 540-552页

作者： CHENG Zhanqi1.2.& ZHONG Zheng1.1. School of Aerospace {1. and Applied mechanics, Tongji university, Shanghai 2.0092.{2. 2. College of Civil {1., Zhengzhou university, Zhengzhou 450002.{2. 1. School of Aerospace engineering and Applied mechanics Tongji University Shanghai 200092 China 2. College of Civil {1. Zhengzhou University Zhengzhou 450002 China

In this paper the plane elasticity problem for a functionally graded interfacial zone containing a crack between two dissimilar homogeneous materials has been considered. It is assumed that in the interfacial zone the reciprocal of the shear modulus is a linear function of the coordinate, while Possion’s ratio keeps constant. By utilizing the Fourier transformation technique and the transfer matrix method, the mixed boundary problem is reduced to a system of singular integral equations that are solved numerically. The influences of the geometric parameters and the graded parameter on the stress intensity factors are investigated. The numerical results show that the graded parameters, the thickness of interfacial zone, the crack size and location have significant effects on the stress intensity factors.

关键词： functionally graded material interfacial zone fracture stress intensity factor

Electric-stimulus rate encoding algorithm of Mandarin tonal information in cochlear implant

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Progress in Natural Science:Materials International 2006年第12期16卷 1315-1321页

作者： GUAN Tian~1. GONG Qin~1.and YE Datian~2.*(1. Department of Biomedical {1., Tsinghua university, Beijing 1.0084,{2. 2. Research Center of Biomedical {1., Graduate School at Shenzhen, Tsinghua university, Shenzhen 51.055,{2.) [a]Department of Biomedical engineering Tsinghua University Beijing China [b]Research Center of Biomedical engineering Graduate School at Shenzhen Tsinghua University Shenzhen China

The modern multi-channel cochlear implants usually extract and encode the temporal envelope cues. This kind of algorithms can hardly satisfy the users who speak tonal languages, such as Mandarin. Many studies have tried to enhance the recognition ability of Mandarin through encoding tonal information and made suggestions to frequency-modulate the fixed pulse-rate carrier with the extracted tonal information based on the rate-pitch theory in electric hearing. However, how to encode and deliver the tonal information such as F_0by changing electric-stimulus rate has not got further study in clinical electric-stimulus mode. The present paper focuses on this matter by piecewise calculating the appreciable electric-stimulus rates. Then an electric-stimulus encoding algorithm of Mandarin tone is brought forward and testified through acoustic simulations. Such conclusion can be drawn that this algorithm of electric-stimulus rate could convey tonal information well and help to enhance the Mandarin speech recognition ability.

关键词： cochlear implant tone fundamental frequency electric-stimulus rate.

Seabed Classification Using BP Neural Network Based on GA

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Acta Oceanologica Sinica 2003年第4期22卷 523-531页

作者： Yang Fanlin1. Liu Jingnan2.1. GPS {1. Research Center, Wuhan university, Wuhan 430079,{2.. 2. Presidential Secretariat, Wuhan university, Wuhan 430079,{2. Wuhan Univ GPS Engn Res Ctr Wuhan 430079 Peoples R China

Side scan sonar imaging is one of the advanced methods for seabed study. In order to be utilized in other projects, such as ocean engineering, the image needs to be classified according to the distributions of different classes of seabed materials. In this paper, seabed image is classified according to BP neural network, and. Genetic Algorithm is adopted in train network in this paper. The feature vectors are average intensity, six statistics of texture and two dimensions of fractal. It considers not only the spatial correlation between different pixels, but also the terrain coarseness. The texture is denoted by the statistics of the co-occurrence matrix. Double Blanket algorithm is used to calculate dimension. Because a uniform fractal may not be sufficient to describe a seafloor, two dimensions are calculated respectively by the upper blanket and the lower blanket. However, in sonar image, fractal has directivity, i. e. there are different dimensions in different direction. Dimensions are different in acrosstrack and alongtrack, so the average of four directions is used to solve this problem. Finally, the real data verify the algorithm. In this paper, one hidden layer including six nodes is adopted. The BP network is rapidly and accurately convergent through GA. Correct classification rate is 9{1.5 % in the result.

关键词： BP network co-occurrence matrix fractal classification genetic algorithin

Construction and application of formal ontology for mine

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中国有色金属学会会刊：英文版 2011年第S3期21卷 577-582页

作者： CHENG Gang 1, 2. ZHANG Yin-ling1, 2. WANG Fei 1 ,2. ZHANG Zhen-hui 3, GUO Yu-xiang1, 2.1. Key Laboratory of Mine Spatial Information Technologies of State Bureau of Surveying and Mapping, Henan Polytechnic university, Jiaozuo 454003, china 2. School of Surveying and land Information {2., Henan Polytechnic university, Jiaozuo 454003, china 3. Qingdao Branch of naval Aeronautical {2. Institute, Qingdao 2.6041, china Henan Polytech Univ Key Lab Mine Spatial Informat Technol State Bur Surveying & Mapping Jiaozuo 454003 Peoples R China Henan Polytech Univ Sch Surveying & Land Informat Engn Jiaozuo 454003 Peoples R China naval Aeronaut Engn Inst Qingdao Branch Qingdao 266041 Peoples R China

Digital mine is the only way for the development of mining industry in china. Due to lack of appropriate standards and norms, and different awareness in the field of digital mine among academia and industry insiders, the meaning for digital mine is still unclear. Starting from the nature of mining and removing of views of specialized fields, this paper constructs formal ontology for digital mine and proposes the four levels for it. The ontology clarifies the concept world for digital mine, defines the meaning of concepts and relations clearly, provides a reference for the standard construction for digital mine and provides a unified semantic framework for the integration of heterogeneous mine data. Meanwhile, it can provide formal reasoning knowledge for expert system of digital mine and improve the intelligence and automation while the machine automatically interpreting and processing mine spatial data.

关键词： Digital mine formalization ontology concept world semantic share

Rock matrix-fractured media model for heterogeneous and fractured coal bed

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中国有色金属学会会刊：英文版 2011年第S3期21卷 621-625页

作者： ZHANG Chun-hui1. YU Guang-ming2. ZHANG Chun1.1. School of Civil {1., Hebei university of Science and Technology, Shijiazhuang 05001.,{2. 2. School of Civil {1., Qingdao Technological university, Qingdao 2.6033,{2. [a] School of Civil engineering Hebei University of Science and Technology Shijiazhuang 050018 China [b] School of Civil engineering Qingdao Technological University Qingdao 266033 China

Coal was considered rock matrix-fractured media composed of rock matrix and fractures, and the rock matrix-fractured media model for heterogeneous and fractured coal bed was presented. In this model the rock matrix is heterogeneous, and the mechanical parameters such as elastic modulus and strength follow Weibull distribution. Fractures in coal bed were generated with the discrete fracture network method, and the properties of fractures were simulated with Desai element. Then the virtual generating system (VGS) of natural heterogeneous and fractured coal bed was developed in Matlab 6.0. The coupled model of gas flow and deformation process based on the rock matrix-fractured media model method and VGS for heterogeneous and fractured coal bed was presented, and the numerical code was developed in Matlab 6.0. The gas flow process in the heterogeneous and fractured coal bed was simulated in a numerical case. The main conclusions are: 1. The natural heterogeneous and fractured coal bed could be simulated by the rock matrix-fractured media model and VGS; 2. The fractures connected with the well have much more effects on gas flow than those non-connected.

关键词： heterogeneity fractures rock matrix-fractured media

The study of adsorption gas sensor based carbon nanotube film

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Science china(Technological Sciences) 2005年第4期48卷 372-384页

作者： LI Xin1. LIU Junhua2.& ZHU Changchun1.1. School of Electronic and Information {1., Xi’an Jiaotong university, Xi’an 71.049,{2. 2. School of Electric {1., Xi’an Jiaotong university, Xi’an 71.049,{2. 1. School of Electronic and Information engineering Xi’an Jiaotong University 710049 Xi’an China 2. School of Electric {1. Xi’an Jiaotong University 710049 Xi’an China

The study of gas sensitivity of multi-wall carbon nanotubes (MWNTs), which is deposited by low press chemical vapor deposition (LPCVD), is presented. The results show that the pure MWNTs are not sensitive to the gases measured, while the composite film consisting of the MWNTs and silicon dioxide is sensitive to the methane, the hydrogen and the acetylene. The MWNTs and silicon dioxide composite film have the capacitance characteristic because of the formation of Schottky junctions within the MWNTs. The chemistry adsorption of the gas measured on the surface of the MWNTs affects the space discharge area of the Schottky junction, so that the dielectric constant changes with the gas concentration. That is why the gas is sensed.

关键词： gas sensor, carbon nanotubes, low press chemical vapor deposition, scatter.