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Empirical likelihood confidence regions of the parameters in a partially linear single-index model

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Science china Mathematics 2005年第10期48卷 1333-1348页

作者： XUE Liugen~1 & ZHU Lixing~2.1. College of Applied Sciences,Beijing university of Technology,Beijing 10002.,china 2. Department of Mathematics,Hong Kong Baptist university,Hong Kong,china 1. College of Applied Sciences Beijing University of Technology 100022 Beijing China 2. Department of Mathematics Hong Kong Baptist University Hong Kong China

In this paper, a partially linear single-index model is investigated, and three empirical log-likelihood ratio statistics for the unknown parameters in the model are suggested. It is proved that the proposed statistics are asymptotically standard chi-square under some suitable conditions, and hence can be used to construct the confidence regions of the parameters. Our methods can also deal with the confidence region construction for the index in the pure single-index model. A simulation study indicates that, in terms of coverage probabilities and average areas of the confidence regions, the proposed methods perform better than the least-squares method.

关键词： partially linear single-index model, empirical likelihood, confidence region, chi-square distribution, coverage probability.

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 Engineering,Shanghai university,Shanghai 2.0072.china 2. School of Transportation Engineering,Tongji university,Shanghai 2.0092.china 1. Department of Civil Engineering Shanghai University Shanghai 200072 China 2. School of Transportation Engineering 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.

Electrical property of 8-mol% yttria-stabilized zirconia electrolyte by spark-plasma sintering

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Science china(Technological Sciences) 2004年第5期47卷 569-576页

作者： JIAN Jiawen1,2. CHANG Aimin3, YANG Bangchao2.& ZHANG Yikang4 1. The School of Information Science Engineering, Ningbo {2., Ningbo 3152.1, china 2. The School of Microelectronics and Solid-state Electronics, {2. of Electronic Science and Tech-nology of china, Chengdu 610054, china 3. The xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, urumqi 83002., china 4. Hongtak (Chengdu) Electronic Co., Ltd, Chengdu 610041, china Correspondence should be addressed to Jian Jiawen 1. The School of Information Science Engineering Ningbo University 315211 Ningbo China 2. The School of Microelectronics and Solid-state Electronics University of Electronic Science and Technology of China 610054 Chengdu China 3. The xinjiang Technical Institute of Physics and Chemistry Chinese Academy of Sciences 830022 Urumqi China 4. Hongtak (Chengdu) Electronic Co. Ltd 610041 Chengdu China

Spark-plasma sintering (SPS) process was used to sinter ZrO2.(8Y) powders, and a relative density of 99% has been reached at a low temperature (1350°C) and short dwelling time (10 min) compared to the conventional sintered identical samples (1450°C 4 h)(CS). By the X-ray diffraction (XRD) patterns, the microstructure of the SPS pellet and CS pellet are both indexed by the cubic unit cell (Fm3m). The finer crystallite size (D111) of the SPS pellet is 154 nm and D111 of the CS pellet is more than 1 μm. The AC impedance spectroscopy shows that the ionic conductivity of SPS pellet is different from that of CS pellet. The activation energy for the SPS ceramics, estimated from the slope in the range of 400–800°C, was 91 kJ mol?1, which is in good agreement with CS pellet (96 kJ mol?1), indicating that the conduction mechanism in SPS ceramics is similar to that in CS ceramics.

关键词： yttria-stabilized zirconia electrolyte, spark-plasma sintering, AC impedance.

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 Engineering 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 92.5 % in the result.

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

Pattern phenomena in an rf discharge dusty plasma system

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Science china(Physics,Mechanics & Astronomy) 2006年第5期49卷 588-596页

作者： HUANG Feng1,2. YE Maofu2.& WANG Long2.1. College of Science, china Agricultural university, Beijing 100083, china 2. Institute of Physics, Chinese Academy of Sciences, Beijing 100080, china 1. College of Science China Agricultural University Beijing 100083 China 2. Institute of Physics Chinese Academy of Sciences Beijing 100080 China

Various dust patterns are observed in an rf discharge dusty plasma system. According to the dust growth process from small to large in size, the formation of different dust patterns can be divided into two stages: the small-particle stage (or dust cloud stage), and the large-particle stage (or dust crystal stage). The evolution relations between different dust patterns with gas pressure changing are investigated. Dust voids, dust acoustic waves and strong turbulence modes are presented at the small-particle stage. The self-organized dust lattices and dust clusters are investigated at the large-particle stage. The static structure of a dust lattice is characterized by means of the pair correlation function. Dust clusters formed by particles with different numbers and the regular evolution of the clusters with gas pressure are also investigated. The packing sequences of dust clusters are verified through two-dimensional confined molecular dynamics simulations.

关键词： dusty plasma dust patterns

Trace element geochemistry of the Lower Cambrian black rock series from northwestern Hunan, South china

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Progress in Natural Science:Materials International 2004年第1期14卷 65-71页

作者： PAN Jiayong 1,2. *, MA Dongsheng 1 and CAO Shuanglin 1,2. (1.The State Key Laboratory for Mineral Deposits Research, Nanjing {2., Nanjing 2.0093, china 2. East china Institute of Technology, Fuzhou 344000, china) Nanjing Univ State Key Lab Mineral Deposit Res Nanjing 210093 Peoples R China E china Inst Technol Fuzhou 344000 Peoples R China

Samples of black rock series collected from the Lower Cambrian Niutitang Formation, northwestern Hunan Province, china, were analyzed for trace elements. The trace element geochemical characteristics of the ore layer (high enrichments of Ni, Mo, V, U, Cu, Pb, Zn, Cd, Tl and Ba; high U/Th ratios and LREE enriched patterns with positive Eu and Y anomalies) support the assumption that the Ni Mo polymetallic layer is of submarine hydrothermal origin. High field strength elements (HFSE) and lithophile elements such as Nb, Ta, Zr, Hf, Li, Be, Rb, Cs, Th and Sc are remarkably higher in the upper unit than those in the lower unit of the Niutitang Formation. These features may reflect that hydrothermal contributions were diminished, and terrigenous constituents were increased in the sediments of the upper unit of the Niutitang Formation.

关键词： black rock series Early Cambrian trace elements northwestern Hunan china

Optimal error bound of restricted Monte Carlo integration on anisotropic Sobolev classes

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Progress in Natural Science:Materials International 2006年第6期16卷 588-593页

作者： GAO Wenhua, YE Peixin and WANG Hui (College of Mathematics and System Sciences, xinjiang university, urumqi 83.046,{{2. School of Mathematical Sciences and LPMC, Nankai university, Tianjin 300071,{{2. Department of Mathematics, Ily Teachers' College, Yining 835000,{{2. College of Science, Hehai university, Nanjing {2.0098,{{2.) [a]College of Mathematics and System Sciences Xinjiang University Urumqi China [b]School of Mathematical Sciences and LPMC Nankai University Tianjin China [c]Department of Mathematics Ily Teachers College Yining China [d]College of Science Hehai University Nanjing China

We study the restricted Monte Carlo integration error for anisotropic Sobolev classes. Results prove that with O(log2.n) random bits we have the optimal order for the n-th minimal Monte Carlo integration error with ar... 详细信息

关键词： Monte Carlo integration random bits anisotropic Sobolev classes.

Architecture and application of integrated spatial information service platform for digital 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 706-711页

作者： ZHANG Jin1, XIAO Jie2.1. College of Mining, Taiyuan university of Technology, Taiyuan 03002., china 2. Institute of Geodesy and Geophysics, Chinese Academy of Sciences, Wuhan 430077, china Taiyuan Univ Technol Coll Min Taiyuan 030024 Peoples R China Chinese Acad Sci Inst Geodesy & Geophys Wuhan 430077 Peoples R China

Using enterprise GIS platform, spatial databases and modern information technology, building geo-spatial information service platform of digital mine which has the features of the data exchange service, enterprise GIS services, directory services, logging services, is key technology and application infrastructure for digital mine. Based on the support of geospatial information service platform of digital mine, the professional GIS application service adapter can be developed and the application supports related to mining application system can be realized. Using high-resolution satellite remote sensing data, the mine functional partition map and geographic grids can be divided, and the geographic grid parts, status and events of important features of the surface object were investigated and defined. The system architecture and technical characteristics of integrated spatial information service platform were analyzed firstly, which guarantee service ability of digital mine. The methods and applications of functional partition map for integrated management service platform were discussed which are the services scheme of digital mine. The application results indicated that digital mine upgrades and enhances the capability and range of mine surveying and mapping, and is of great significance for guarantee of efficient, green and intensive exploitation of mine.

关键词： platform architecture web services application services digital mine

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 Engineering, Xi’an Jiaotong university, Xi’an 710049,{2. 2. School of Electric Engineering, Xi’an Jiaotong university, Xi’an 710049,{2. 1. School of Electronic and Information Engineering Xi’an Jiaotong University 710049 Xi’an China 2. School of Electric Engineering 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.