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Journal of Wuhan University of Technology(Materials science) 2011年第2期26卷 312-315页

作者：胡长征 state laboratory Breeding Base of Nonferrous Metals and specific Materials Processing Guilin University of Technology key laboratory of Nonferrous Materials and New Processing Technology Ministry of EducationGuilin University of Technology state key laboratory of Advanced Technology for Materials synthesis and Processing Wuhan University of Technology

Compounds sr4Eu2Ti4Nb6O30 and sr5EuTi3Nb7O30 with filled tetragonal tungsten bronze structure were prepared,and the dielectric characteristics and ferroelectric transition were *** ceramics displayed weak frequency dependence in room temperature dielectric constant,which decreased from 125 to 118 for sr4Eu2Ti4Nb6O30,from 206 to 195 for sr5EuTi3Nb7O30 in the frequency range of 10 kHz to 1 *** present ceramics showed a diffuse ferroelectric phase *** frequency independent transition temperature （Tm） indicated the above compounds had no relaxor *** diffuseness （γ） was 1.45 and 1.64 for sr4Eu2Ti4Nb6O30 and sr5EuTi3Nb7O30 *** weak ferroelectric of the present materials are indicated from the P-E hysteresis loops,and a small 2Pr of 0.596 μC/cm2 and 0.068 μC/cm2 were observed for sr4Eu2Ti4Nb6O30 and sr5EuTi3Nb7O30 respectively.

关键词： tungsten bronze dielectric properties X-ray diffraction phase transition

Integrated modeling of nitrogen oxides formation in diesel engines

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Progress in Natural science:Materials International 2007年第12期17卷 1476-1481页

作者： song Jinou, Yao Chunde and Wang Hongfu(state key laboratory of Engine, Tianjin University, Tianjin 300072, china) state key laboratory of Engine Tianjin University Tianjin 300072 China

To account for the effects of both chemistry and flow turbulence, the present study proposes an integrated NO sub-model that combines the extended Zel’dovich mechanism and engine CFD computations to simulate the NO histories in a diesel engine. NOx sub-model parameters and pollutant formation mechanisms can be more easily investigated by solving the NOx sub-model. The new NO formation model incorporating the effects of both chemical kinetics and turbulent mixing was applied to simulate a diesel engine with a quiescent combustion chamber, and one with a re-entrant combustion chamber; the premise of the model being the reaction rate is mainly determined by a kinetic timescale and a turbulent timescale. The results indicate that the predicted NO formulation from the new model agrees well with the measured data. As the utilization of fossil fuels continues to increase, the control of NOx emissions is a worldwide concern; and it is imperative to understand fully the NOx reaction processes in combustion systems. This technology has the potential to enhance the application of various combustion techniques used to reduce NOx emissions from practical combustion systems.

关键词： nitrogen oxides (NOx) combustion turbulence diesel.

Thermoelastic properties of sandwich materials with pin-reinforced foam cores

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science china(Technological sciences) 2008年第12期51卷 2059-2074页

作者： LU TianJian1,LIU Tao2,3 & DENG ZiChen2,4 1 MOE key laboratory of strength and Vibration,school of Aerospace,xi’an Jiaotong University,xi’an 710049,china 2 Department of Engineering Mechanics,Northwestern Polytechnical University,xi’an 710072,china 3 Department of Engineering,University of Cambridge,Cambridge CB2 1PZ,UK 4 state key laboratory of structural Analysis of Industrial Equipment,Dalian University of Technology,Dalian 116024,china MOE key laboratory of strength and Vibration School of Aerospace Xi’an Jiaotong University Xi’an China Department of Engineering Mechanics Northwestern Polytechnical University Xi’an China Department of Engineering University of Cambridge Cambridge UK state key laboratory of structural Analysis of Industrial Equipment Dalian University of Technology Dalian China

Pin-reinforced foam is a novel type of sandwich core materials formed by inserting pins(trusses) into a foam matrix to create a truss-like network reinforced foam *** loading,the pins deform predominantly by local stretching whilst the deformation of foam is governed by local *** paper presents a theoretical study on the thermoelasticity of pin-reinforced foam sandwich *** calculate the effective thermoelastic properties of pin-reinforced foam cores,the energy-based homogenization approach is employed to develop a micromechanics-based model,calibrated by the existing experimental *** is found that the stiffness of the sandwich core is mainly governed by pin reinforcements:the foam matrix contributes little to sandwich *** with traditional foam cores without pin reinforcements,the changes in inplane thermal expansion coefficients are not vigorous as a result of pin reinforcements,while the through-thickness thermal expansion coefficient changes *** is also demonstrated that it is possible to design materials with zero or negative thermal expansion coefficients under such a context.

关键词： sandwich panel pin reinforcement analytical solutions homogenization thermoelasticity thermal expansion

Variational Neural Inference Enhanced Text semantic Communication system

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china Communications 2024年第7期21卷 50-64页

作者： Zhang xi Zhang Yiqian Li Congduan Ma xiao school of Electronics and Communication Engineering Sun Yat-Sen UniversityShenzhen 518107China Guizhou University state key laboratory of Public Big Data Guiyang 550025China shenzhen key laboratory of Navigation and Communication Integration Shenzhen 518107China school of Computer science and Engineering Sun Yat-Sen UniversityGuangzhou 510006China

Recently,deep learning-based semantic communication has garnered widespread attention,with numerous systems designed for transmitting diverse data sources,including text,image,and speech,*** efforts have been directed toward improving system performance,many studies have concentrated on enhancing the structure of the encoder and ***,this often overlooks the resulting increase in model complexity,imposing additional storage and computational burdens on smart ***,existing work tends to prioritize explicit semantics,neglecting the potential of implicit *** paper aims to easily and effectively enhance the receiver's decoding capability without modifying the encoder and decoder *** propose a novel semantic communication system with variational neural inference for text ***,we introduce a simple but effective variational neural inferer at the receiver to infer the latent semantic information within the received *** information is then utilized to assist in the decoding *** simulation results show a significant enhancement in system performance and improved robustness.

关键词： deep learning semantic communication variational neural inference

Influence of Ordovician carbonate reservoir beds in Tarim Basin by faulting

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science china Earth sciences 2008年第S2期51卷 53-60页

作者： L xiuxiang1,2,YANG Ning1,2,ZHOU xinYuan3,YANG HaiJun3 & LI JianJiao1,2 1 Faculty of Natural Resource & Information Technology,china University of Petroleum,Beijing 102249,china 2 state key laboratory of Petroleum Resource and Prospecting,china University of Petroleum,Beijing 102249,china 3 Tarim Oilfield,Petrochina,Korla 841000,china Faculty of Natural Resource & Information Technology China University of Petroleum Beijing China state key laboratory of Petroleum Resource and Prospecting China University of Petroleum Beijing China Tarim Oilfield PetroChina Korla China

The quality of the Ordovician carbonate reservoir beds in the Tarim Basin is closely related to the development of secondary pores,fractures and cavities. Karstification is important in improving the properties of reservoir beds,and karstification related to unconformity has caught wide attention. Compared with the recent research on the unconformity karst reservoir bed improvement,this paper shows a new way of carbonate reservoir bed transformation. Based on field survey,core and slices observation,transformation of Ordovician carbonate reservoir beds by faulting can be classified into three types: (1) secondary faults and fracturs generated by faulting improved carbonate reservoir bed properties,which were named the Lunnan or Tazhong82 model; (2) upflow of deep geothermal fluids caused by faulting,with some components metasomatizing with carbonate and forming some secon-dary deposit,such as fluorite. It can improve carbonate reservoir bed properties obviously and is named the Tazhong 82 model; and (3) the faulting extending up to the surface increased the depth of supergene karstification and the thickness of reservoir bed. It is named the Hetianhe model. Trans-formation effect of carbonate reservoir beds by faulting was very significant,mainly distributed on the slopes or on the edge or plunging end of the uplift.

关键词： carbonate faulting reservoir transformation Ordovician Tarim Basin

METHODs OF MODERN DEsIGN FOR CYLINDRICAL GEAR DRIVE BAsED ON THE INTERNET

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Chinese Journal of Mechanical Engineering 2002年第1期15卷 62-65页

作者： Lin Chao Li Runfang state key laboratory of Mechanical Transmission，Chongqing University， Chongqing 400044，china Chongqing University State Key Laboratory of Mechanical Transmission 重庆 400044

The basic principle of modern design of cylindrical gear drive based on theInternet is described. The methods of optimized design, finite element analysis, CAD design and webdesign as well as research and development entity of three parties such as institute research unit(or university), enterprise and customer are also studied. Its purpose is to provide a necessaryfoundation for realizing the design of cylindrical gear drive from different location on the modemInternet and to explore a practice application route.

关键词： Internet Cylindrical gear Mechanical model

Effects of boundary conditions on vibrating mode of acoustic logging dipole transducer

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science china Earth sciences 2008年第S2期51卷 195-200页

作者： QIAO Wenxiao,CHE xiaoHua & ZHANG Fei state key laboratory of Petroleum Resource and Prospecting,china University of Petroleum,Beijing 102249,china state key laboratory of Petroleum Resource and Prospecting China University of Petroleum Beijing China

Acoustic transducer is an important part of acoustic well logging tool. In this paper,ANsYs software package is used to design acoustic dipole transducer and simulate vibrating mode of the dipole transducer in different mechanical boundary conditions. The results show that boundary conditions influence the number of vibrating mode in the same frequency band and the frequency value of the same vibrating mode. several acoustic dipole transducers are designed according to the results of numerical simulation and laboratory measurements. The basic frequency of vibrating mode of experi-ment has good agreement with that of simulation. The numerical simulation plays a good guidance role in designing,producing and correctly installing the acoustic dipole transducer.

关键词： acoustic dipole transducer vibrating mode basic frequency acoustic well logging

solar energetic particles intensity variations associated with a tilted-dipole 3D corotating interaction region

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Earth and Planetary Physics 2024年第5期8卷 797-810页

作者： YuJi Zhu Fang shen xi Luo Yang Wang BoFeng Tang state key laboratory of space Weather National Space Science Center Chinese Academy of Sciences shandong Institute of Advanced Technology (sDIAT) College of Earth and Planetary sciences University of Chinese Academy of Sciences school of science Harbin Institute of Technology

The effect of a tilted-dipole three-dimensional corotating interaction region(CIR) on the transport and acceleration of solar energetic particles(sEPs) is *** this work,we discussed how the particle intensity longitudinal and radial dependence might be influenced by the background ***,we investigate how the spectral index distribution is modulated by the CIR structure We use the focused transport equation(FTE) to describe the propagation and acceleration of sEPs in a tilt-dipole 3D CIR,generated by the high-resolution 3D magnetohydrodynamic(MHD) *** forward stochastic differential method is used to solve the *** protons with theE～(-4.4)spectrum from 0.5 to 15 MeV are injected uniformly at the heliographic equator of 0.15 *** quantities are extracted along each interplanetary magnetic field(IMF) line to show the *** the tilted-dipole CIR background,if injected from the solar equator at the inner boundary,particles in the slow flow are transported to higher latitudes due to the extension of the IMF lines to higher *** longitudinal patterns of the particles are dominated by the density of IMF *** focusing effect modulates the longitudinal variation of the particle intensity and gives rise to new longitudinal intensity *** adiabatic effect largely increases the intensity fluctuation along the *** structure of the solar wind can also lead to the difference of the index α in the empirical functionI＿(max)=kR～(-α),describing the radial variation of peak intensity according to our *** the influence of the CIR structure,the index α varies from 1.9 to 3.4 at 0.3-1.0 *** variation of the solar wind speed should be considered when estimating the radial dependence of the sEP peak *** spectra indices rise near the CIR boundaries and drop near the stream interface(sI).The adiabatic effect makes the spatial variability of the spectral index *** spectral index could be sim

关键词： solar energetic particle (sEP) corotating interaction regions (CIR) magnetohydrodynamic (MHD)

Post-earthquake assessment of building damage degree using LiDAR data and imagery

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science china(Technological sciences) 2008年第S2期51卷 133-143页

作者： LI ManChun1,CHENG Liang1,2,GONG JianYa2,LIU YongXue1,CHEN ZhenJie1,LI FeiXue1,CHEN Gang1,CHEN Dong1 & sONG xiaoGang3 1 Department of Geographic Information science,Nanjing University,Nanjing 210093,china 2 state key laboratory of Information Engineering in surveying,Mapping and Remote sensing,Wuhan University,Wuhan 430079,china 3.state key laboratory of Earthquake Dynamics,Institute of Geology,china Earthquake Administration,Beijing 100029,china Department of Geographic Information science Nanjing University Nanjing China state key laboratory of Information Engineering in surveying Mapping and Remote Sensing Wuhan University Wuhan China state key laboratory of Earthquake Dynamics Institute of Geology China Earthquake Administration Beijing China

Various methods have been developed to detect and assess building's damages due to earthquakes using remotely sensed *** the launch of the high resolution sensors such as IKONOs and QuickBird,it becomes realistic to identify damages on the scale of individual *** the low accuracy of the results has often led to the use of visual interpretation ***,it is very difficult to estimate the degree of building damage(*** damage,moderate damage,or severe damage) in detail using the existing ***,a novel approach integrating LiDAR data and high resolution optical imagery is proposed for evaluating building damage degree *** approach consists of two steps:3D building model reconstruction and rooftop patch-oriented 3D change ***,a method is proposed for automatically reconstructing 3D building models with precise geometric position and fine details,using pre-earthquake LiDAR data and high resolution ***,focusing on each rooftop patch of the 3D building models,the pre- and post-earthquake LiDAR points belonging to the patch are collected and compared to detect whether it was destroyed or not,and then the degree of building damage can be identified based on the ratio of the destroyed rooftop patches to all rooftop *** novelty of the proposed approach is to detect damages on the scale of building's rooftop patch and realize quantitative estimation of building damage degree.

关键词： post-earthquake assessment building damage degree rooftop patch LiDAR imagery

Dominant point detecting based non-uniform B-spline approximation for grain contour

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science china(Technological sciences) 2007年第1期50卷 90-96页

作者： ZHAO xiuYang1, YIN Yansheng1,2 & YANG Bo3 1 shandong key laboratory of Engineering Ceramics, shandong University, Jinan 250061, china 2 school of Materials, Ocean University of china, Qingdao 266003, china 3.state key laboratory of Advanced Technology for Materials synthesis and Processing, Wuhan University of science and Technology, Wuhan 430070, china shandong key laboratory of Engineering Ceramics Shandong University Jinan China school of Materials Ocean University of China Qingdao China state key laboratory of Advanced Technology for Materials synthesis and Processing Wuhan University of Science and Technology Wuhan China

Three-dimension reconstruction from serial sections has been used in the last decade to obtain information concerning three-dimensional microstructural ge-ometry. One of the crucial steps of three-dimension reconstruction is getting compact and fairing grain contours. Based on the achievement of closed raw con-tours of ceramic composite grains by using wavelet and level set, an adaptive method is adopted for the polygonal approximation of the digitized raw contours. Instead of setting a fixed length of support region in advance, the novel method computes the suitable length of support region for each point to find the best es-timated curvature. The dominant points are identified as the points with local maximum estimated curvatures. Periodic closed B-spline approximation is used to find the most compact B-spline grain boundary contours within the given tolerance. A flexible distance selection approach is adopted to obtain the common knot vector of serial contours consisting of less knots that contain enough degrees of freedom to guarantee the existence of a B-spline curve interpolating each contour. Finally, a B-spline surface interpolating the serial contours is generated via B-spline surface skinning.

关键词： composite B-spline dominant points control points grain contour