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A coupled elasto-plastic-damage mechanical model for marble

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Science china(Technological Sciences) 2011年第S1期54卷 228-234页

作者： ZHOU Hui 1,ZHANG Kai 2 & FENG XiaTing 1 1 state key laboratory of Geomechanics and Geotechnical engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,wuhan 430071,china 2 state key laboratory for Geomechanics and Deep Underground engineering,china university of Mining&Technology,Xuzhou 221008,china 1. state key laboratory of Geomechanics and Geotechnical engineering Institute of Rock and Soil Mechanics Chinese Academy of Sciences Wuhan 430071 China 2. state key laboratory for Geomechanics and Deep Underground engineering China University of Mining & Technology Xuzhou 221008 China

A profound understanding of the mechanical behaviors of marble is very important for the design and construction of deep diversion tunnels in Jinping II hydropower *** this paper,a coupled elasto-plastic-damage mechanical model is presented for Jinping ***,the experimental investigations on Jinping marble are ***,based on the framework of continuum damage and plastic theories,a general mechanical model is proposed to predict the mechanical responses of Jinping *** proposed model is used to simulate the triaxial compressive tests,and there is a general good agreement between experimental data and numerical predictions in a qualitative *** proposed model is able to capture the main features of Jinping marble observed in experiments,such as progressive yielding process,damage induced by plastic distortion,dilation,elastic degradation and stress sensitivity.

关键词： mechanical model damage elasto-plastic coupling marble

Preparation and Characterization of Chitosan/Carboxymethylated Konjac Glucomannan Blend Films

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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 university of Technology, wuhan 430070, Hubei, china 2. College of Chemistry and Molecular Sciences, wuhan university, wuhan 430072, Hubei, china wuhan university of Technology 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

Land use data generalization indices considering scale and land use pattern effects

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Science china Earth Sciences 2011年第5期54卷 694-702页

作者： LIU YaoLin1,2,JIAO LiMin1,2 & LIU YanFang1,2 1 School of Resource and Environmental Sciences,wuhan university,wuhan 430079,china 2 key laboratory of Geographic Information System,Ministry of Education,wuhan university,wuhan 430079,china 1. School of Resource and Environmental Sciences Wuhan University Wuhan 430079 China2. Key Laboratory of Geographic Information System Ministry of Education Wuhan University Wuhan 430079 China

Land use generalization indices are critical for producing normative multi-scale land use databases and maps,but there is still not a national criterion for these indices in *** studies on land use data generalization indices often neglect macroindices such as area proportion of land use types and map load,and also ignore landscape effects on land use generalization *** we constructed an index system of land use data generalization from macro-and micro-perspectives,and examined scale and landscape effects on land use data generalization indices based on the countrywide multi-scale land use data *** formulated relationships between land use data generalization indices and both scale and land use pattern *** defined thresholds of land use data generalization indices on scales of 1:50000,1:100000,1:250000,and 1:*** verified our methodology and index thresholds through generalizing a county land use database.

关键词： land use database land use database generalization generalization indices land use pattern landscape metrics

Computer System Reliability Allocation Method and Supporting Tool

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wuhan university Journal of Natural Sciences 2001年第Z1期6卷 505-510页

作者： Ben Ke\|rong 1, Yan Jiong 2, Wang Ji 2 1 Department of Computer Science, Naval university of engineering, wuhan 430033, china software engineering key Lab.,wuhan university,wuhan 430072, china 2 Department of Computer Science, National Universit Department of Computer Science Naval University of Engineering Wuhan China software engineering key Lab. Wuhan University Wuhan China Department of Computer Science National University of Defence Technology Changsha China

This paper presents a computer system reliability allocation method that is based on the theory of statistic and Markovian chain,which can be used to allocate reliability to subsystem, to hybrid system and software mo... 详细信息

关键词： software Reliability reliability allocation method supporting tool

A New Evolutionary Algorithm for Function Optimization

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wuhan university Journal of Natural Sciences 1999年第4期4卷 409-414页

作者： GUO Tao, KANG Li shan state key laboratory of software engineering, wuhan university,wuhan 430072, china wuhan university State Key Laboratory of Software Engineering Wuhan China (GRID:grid.49470.3e) (ISNI:***)

A new algorithm based on genetic algorithm(GA) is developed for solving function optimization problems with inequality constraints. This algorithm has been used to a series of standard test problems and exhibited good performance. The computation results show that its generality, precision, robustness, simplicity and performance are all satisfactory.

关键词： key words evolutionary algorithm function optimization problem inequality constraints

Electronic Structure and Thermoelectric Properties of Na and Ni-doped Ca_3Co_2O_6

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Journal of wuhan university of Technology(Materials Science) 2006年第3期21卷 94-96页

作者：闵新民 Department of Applied Chemistry Wuhan University of Technology Wuhan 430070 ChinaState Key Laboratory of Advanced Technology for Materials Synthesis and ProcessingWuhan University of Technology Wuhan 430070China

The electronic structures of Ca3Co2O6, Na and Ni doped models were studied by the quantum chemical software of Cambride Serial Total Energy Package （CASTEP） that is based on deusity function theory （DFT） and psendo-potential. The electronic conductivity, seebeck coefficient, thermal conduetivity and figure of merit （Z） were computed. The energy band structure reveals the form of the impurity levels due to the substitutional imapurity in semiconductors. Na-doped model stunts the character of p-type semiconductor, but Xi-doped model is n-type semiconductor. The calculation results show that the electric conduetirity of the doped model is higher than that of the non-doped model, while the Seebeck coefficient and thermal conductivity of the doped model are lower than those of the non-doped one. Because of the great increase of the electric conductivity, Z of Na- doped model is enhanced and thermoelectric properties are improved. On the other hand, as the large decline of Seebeck coefficient, Z of Ni-doped model is less than that of the non-doped model.

关键词： cobalt oxide substitutional impurity quantum chemical calculation electronic structure thermoelectric property

GRACE detection of the medium-to far-field coseismic gravity changes caused by the 2004 Mw9.3 Sumatra-Andaman earthquake

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Earthquake Science 2012年第3期25卷 235-240页

作者： Jin Li1,2,3 and Wenbin Shen1,3,4, 1 Department of Geophysics, School of Geodesy and Geomatics, wuhan university, wuhan 430079, china 2 key laboratory of Geodynamic Geodesy of Chinese Academy, wuhan 430077, china 3 key laboratory of Geospace Environment and Geodesy (Ministry of Education), wuhan university, wuhan 430079, china 4 state key laboratory of Information engineering in Surveying, Mapping and Remote Sensing, wuhan 430079, china 1. Department of Geophysics School of Geodesy and Geomatics Wuhan University Wuhan 430079 China 2. key laboratory of Geodynamic Geodesy of Chinese Academy Wuhan 430077 China 3. key laboratory of Geospace Environment and Geodesy (Ministry of Education) Wuhan University Wuhan 430079 China 4. state key laboratory of Information engineering in Surveying Mapping and Remote Sensing Wuhan 430079 China

Large earthquakes cause observable changes in the Earth’s gravity field, which have been detected by the Gravity Recovery and Climate Experiment (GRACE). Since most previous studies focus on the detection of near-field gravity effects, this study provides the results from the medium- to far-field gravity changes caused by the 2004 Sumatra-Andaman earthquake that are recorded within GRACE monthly solutions. Utilizing a spherical-earth dislocation model we documented that large-scale signals predominate in the global field of the coseismic gravity changes caused by the earthquake. After removing the near-field effects, the coseismic gravity changes show a negative anomaly feature with an average magnitude of -0.18×10-8 m·s-2 in the region ranging ～40° from the epicenter, which is considered as the 'medium ffield' in this study. From the GRACE data released by Center for Space Research from August 2002 to December 2008, we retrieved the large-scale gravity changes smoothed with 3 000 km Gaussian ffilter. The results show that the coseismic gravity changes detected by GRACE in the medium field have an average of (-0.20±0.06)×10-8 m·s-2, which agrees with the model prediction. The detection confirms that GRACE is sensitive to large-scale medium-field coseismic gravitational effects of mega earthquakes, and also validates the spherical-earth dislocation model in the medium field from the perspective of satellite gravimetry.

关键词： GRACE medium-to far-field coseismic gravity change 2004 Sumatra-Andaman earthquake spherical-Earth dislocation model

A multi-scale and multi-orientation image retrieval method based on rotation-invariant texture features

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Science china(Information Sciences) 2011年第4期54卷 732-744页

作者： SHAO ZhenFeng,LI DeRen & ZHU XianQiang state key laboratory for Information engineering in Surveying,Mapping and Remote Sensing,wuhan university,129 Luoyu Road,wuhan 430079,china 1. state key laboratory for Information engineering in Surveying Mapping and Remote Sensing Wuhan University 129 Luoyu Road Wuhan 430079 China

Texture retrieval is a vital branch of content-based image ***-invariant texture retrieval plays a key role in texture *** paper addresses three major issues in rotation-invariant texture retrieval: how to select the texture measurement methods,how to alleviate the influence of rotation for texture retrieval and how to apply the proper multi-scale analysis theory for texture ***,the spectrum influence between a Radon transform and a Log-polar transform was compared after the rotation effect was *** average retrieval performance of wavelet and NSCT with different retrieval parameters was also *** on such analysis,we developed a multi-scale and multi-orientation texture transform spectrum,as well as a rotation-invariant feature vector and its measurement criteria,which can represent the human visual perception sensitive to texture *** a new rotation-invariant texture retrieval algorithm was *** algorithm was developed based on non-parametric statistical features and it applies low band and high frequency directional bands of NSCT coefficients for coarse filtering and fine retrieval,*** on the Brodatz image database show that the constructed rotation-invariant feature vector is appropriate for capturing major orientations and describing detail ***,the combination of the two-step progressive retrieval strategy and multi-scale analysis method can effectively improve retrieval efficiency while ensuring a high precision compared with traditional algorithms.

关键词： NSCT Log-polar Radon rotation-invariant texture retrieval

A METHOD TO APPROACH OPTIMAL RESTORATION IN IMAGE RESTORATION PROBLEMS WITHOUT NOISE ENERGY INFORMATION

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Acta Mathematica Scientia 2003年第4期23卷 512-520页

作者：曾三友丁立新康立山 state key laboratory of software engineering Wuhan University Wuhan 430072 China Deptartment of Computer Science Zhuzhou Institute of Technology Zhuzhou 402008 China state key laboratory of software engineering Wuhan University Wuhan 430072 China

This paper proposes a new image restoration technique, in which the resulting regularized image approximates the optimal solution steadily. The affect of the regular-ization operator and parameter on the lower band and upper band energy of the residue of the regularized image is theoretically analyzed by employing wavelet transform. This paper shows that regularization operator should generally be lowstop and highpass. So this paper chooses a lowstop and highpass operator as regularization operator, and construct an optimization model which minimizes the mean squares residue of regularized solution to determine regularization parameter. Although the model is random, on the condition of this paper, it can be solved and yields regularization parameter and regularized solution. Otherwise, the technique has a mechanism to predict noise energy. So, without noise information, it can also work and yield good restoration results.

关键词： Regularization method image restoration wavelet transform