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Multi-channel neural mass modelling and analyzing

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Science china(Information Sciences) 2011年第6期54卷 1283-1292页

作者： CUI Dong 1 , LI XiaoLi 2 , JI XueQing 3.& LIU LanXiang 3.1 institute of Information Science and engineering, Yanshan University, Qinhuangdao 066004, china 2 institute of Electrical engineering, Yanshan University, Qinhuangdao 066004, china 3.the No.1 Hospital of Qinhuangdao, Qinhuangdao 066000, china 1. institute of Information Science and engineering Yanshan University Qinhuangdao 066004 China2. Institute of Electrical Engineering Yanshan University Qinhuangdao 066004 China3. The No.1 Hospital of Qinhuangdao Qinhuangdao 066000 China

Multi-channel neural signals generated by a computational model can help understand the mechanism of EEG rhythms, analyze brain functional connectivity and evaluate neural signal processing methods. In this study, a two-kinetics lumped-parameter neural mass model is extended to a multi-kinetics and multi-channel coupled model. this new model can effectively simulate the coupled dynamics activities between different areas in the brain. the simulation results show that the proposed model can generate neural signals with various frequency bands, from delta wave (1-4 Hz) to gamma wave (3.-70 Hz), and the dynamics of the simulated neural signals is more complicated. the simulation analysis can also reveal the relationship between the coupled neural networks and the rhythm of neural populations, and the simulated neural signals can present the bi-modal and uni-modal phenomenon in the frequency domain when the coupling strength of models increases. Finally, analysis of an epileptic EEG signal from a rat demonstrates that the coupling among the neural populations can induce a large-scale seizure.

关键词： multi-channel neural mass model coupling spectrum synchronization epilepsy

research on stability of the accumulated rock-soil body of reservoir bank under rainfall condition

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Science china(Technological Sciences) 2009年第9期52卷 2528-2535页

作者： GU ChongShi1,2,WU HaiZhen1,2 & SU HuaiZhi1,2 1 College of Water Resources and Hydropower engineering,Hohai University,Nanjing 210098,china 2 National engineering {3. Center of Water Resources Efficient Utilization and engineering Safety,Hohai University,Nanjing 210098,china 3.Jiangxi Water Conservancy {3. institute,Nanchang 3.0029,china 1. College of Water Resources and Hydropower engineering Hohai University Nanjing 210098 China 2. National engineering research Center of Water Resources Efficient Utilization and engineering Safety Hohai University Nanjing 210098 China 3. Jiangxi Water Conservancy research institute Nanchang 330029 China

the shear strength parameters property of rock-soil aggregates in embankment slope of reservoir,that is,the relationship between cohesion and gravel content,between friction angle and gravel content,and the relationship between cohesion and water content,between friction angle and water content,is studied based on the direct shear test results,the shear strength change law of the rock-soil aggregates is given,and the unsaturated shear strength formulation of rock-soil aggregates that could consider suction and saturation degree influence is put forward in this paper,through which the sliding or failure physical mechanism of this type of slope under the condition of rainfall infiltration is studied. Also the 3D unsteady saturated-unsaturated seepage field and its FEM resolving mode are established based on the analysis of the slope rainfall infiltration process. Case study with this method indicates that the minimum safety factor of the accumulated rock-soil aggregates dose not arrive at the moment of rainfall cessation,but appears several hours after the rainfall cessation,this phenomenon is in accordance with the practical slope engineering's failure process and could explain appropriately the slope failure caused by rainfall infiltration. research results in this paper have an important reference value for the research on stability of the accumulated rock-soil aggregates in embankment slope of reservoir,and can enrich the stability analysis method and relevant theory of reservoir embankment slope.

关键词： reservoir bank slope rock-soil aggregates rainfall infiltration saturated/unsaturated seepage

theoretical study of ZnO adsorption and bonding on Al_2O_3.0001) surface

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Science china(Physics,Mechanics & Astronomy) 2004年第6期47卷 664-675页

作者： LI Yanrong1,YANG Chun1,2,XUE Weidong1,LI Jinshan3.& LIU Yonghua3.1.institute of Microelectronics and Solid State Electronics,University of Electronic Science and Technol- ogy of china,Chengdu 610054,china 2.institute of Mathematics and Software Science,Sichuan Normal University,Chengdu 610068,china 3.institute of Chemical Materials,china Academy of engineering Physics,Mianyang 621000,china institute of Microelectronics and Solid State Electronics University of Electronic Science and Technology of China Chengdu 610054 China institute of Mathematics and Software Science Sichuan Normal University Chengdu 610068 China institute of Chemical Materials China Academy of Engineering Physics Mianyang 621000 China

ZnO adsorption on sapphire (0001) surface is theoretically calculated by using a plane wave ultrasoft pseudo-potential method based on ab initio molecular dynamics. the results reveal that the surface relaxation in the first layer Al-O is reduced, even eliminated after the surface adsorption of ZnO, and the chemical bonding energy is 43..3.±3..6) kJ·mol?1. the chemical bond of ZnO (0.185 ± 0.01 nm) has a 3.° angle away from the adjacent Al-O bond, and the stable chemical adsorption position of the Zn is deflected from the surface O-hexagonal symmetry with an angle of about 3.°. the analysis of the atomic populations, density of state and bonding electronic density before and after the adsorption indicates that the chemical bond formed by the O2 of the ZnO ? and the surface Al3. has a strong ionic bonding characteristic, while the chemical bond formed by the Zn2+ and the surface O2 has an obvious covalent characteristic, which ? comes mainly from the hybridization of the Zn 4s and the O 2p and partially from that of the Zn 3. and the O 2p.

关键词： α-Al2O3.(0001) ZnO ab initio molecular dynamics chemical adsorption density of states

the Wenchuan earthquake creation of a rich database of building performance

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Science china(Technological Sciences) 2010年第10期53卷 2668-2680页

作者： SUN BaiTao & ZHANG GuiXin institute of engineering Mechanics, china Ear{3.quake Administration, Harbin 150080, china 1. institute of engineering Mechanics China Earthquake Administration Harbin 150080 China

After the Wenchuan earthquake,the {3. of engineering Mechanics (IEM) performed an extensive and comprehensive damage survey of the large area affected by the earthquake. Seismic codes in china were revised and updated after the catastrophic 1976 Tangshan earthquake. However,until the Wenchuan earthquake the seismic code provisions were not tested by a large earthquake. Some 5000 buildings,exposed to intensities VI to XI,were investigated in great detail immediately after the earthquake. the investigation and the surveys covered both seismically designed (fortified) buildings and non-code compliant buildings. In the process a comprehensive and documented database of building performance was compiled,which would be very valuable for further {3.,improvement of the seismic code,improvement of the construction practices,and disaster mitigation planning and management. the database dominantly contains the most prevalent structural types in the region: 1) reinforced and un-reinforced masonry structures; 2) masonry buildings with reinforced frame in the lower stories,and 3. reinforced concrete frame structures. Observed damage characteristics of various structural types were studied and documented,damage patterns analyzed,and corresponding damage probability matrices derived from the data collected during this survey. It is our hope that this investigation and the published material will be utilized for the revision of the seismic codes,leading to a higher level of life safety and damage reduction in future earthquakes.

关键词： Wenchuan earthquake building damage vulnerability damage probability matrices

Early Hydration of Composite Cement with thermal Activated Coal Gangue

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Journal of Wuhan University of Technology(Materials Science) 2010年第1期25卷 162-166页

作者：郭伟 Department of Material engineering Yancheng Institute of Technology institute of Material Science and engineering Nanjing University of Technology

Composite cement samples were prepared by mixing clinker, gypsum with burnt coal gangues which was calcined at various temperatures. the mechanical strength and Ca（OH）2 content in the cement paste were tested, and the paste composition and microstructure were analyzed by thermogravimetry-differential thermal analysis （TG-DSC）, X-ray diffraction（XRD）, scanning electronic microscopy （SEM） and pore structure analysis. Results demonstrate that the thermal activated coal gangue could accelerate the early hydration of cement clinker obviously, which promotes the gangue hydration itself. the early hydrated products of the cement are C-S-H gel, Ca（OH）2 and AFt. the cement with 3.% （in mass） the gangue exhibits higher mechanical strength, and among all the cement samples the one with the gangue burnt at 700 ℃ displays the highest hydration rate, mechanical strength, the most gel pores and the lowest total porosity.

关键词： blended cement hydration microstructure hydration product

Building damage in Dujiangyan during Wenchuan Earthquake

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Earthquake engineering and engineering Vibration 2008年第3期7卷 263-269页

作者： Zhang Minzheng and Jin Yingjie institute of engineering Mechanics, china Ear{3.quake Administration, Harbin 150080, china Professor Graduate Student institute of engineering Mechanics China Earthquake Administration Harbin 150080 China

A field damage survey of 1,005 buildings damaged by the Wenchuan Earthquake in Dujiangyan City was carried out and the resulting data was analyzed using the statistical method. It is shown that buildings that were seismically designed achieved the desired seismic fortification target; they sustained less damage than the non-seismically designed buildings. Among the seismically designed buildings investigated, RC frame buildings performed the best in terms of seismic resistance. Masonry buildings with a ground story of RC frame structure were the second best, and masonry buildings performed the worst. Considering building height, multistory buildings sustained more severe damage than high-rise buildings and 2- and 3.story buildings. Compared to residential buildings, public buildings, such as schools and hospitals, suffered more severe damage.

关键词： Wenchuan Earthquake Dujiangyan building damage seismic intensity field survey

Numerical and experimental investigation of the fracture behavior of shock loaded alumina

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Science china(Physics,Mechanics & Astronomy) 2010年第2期53卷 244-252页

作者： REN HuiLan1,SHU XueFeng2 & LI Ping3.1 State Key Laboratory of Explosion Science and Technology,Beijing institute of Technology,Beijing 100081,china 2 institute of Applied Mechanics and Biomedical {3.,Taiyuan University of Technology,Taiyuan 03.024,china 3.Labroratory for Shock Wave and Detonation Physics research,institute of Fluid Physics,CAEP,Mianyang 610059,china 1. State Key Laboratory of Explosion Science and Technology Beijing Institute of Technology Beijing 100081 China2. Institute of Applied Mechanics and Biomedical Engineering Taiyuan University of Technology Taiyuan 030024 China3. Labroratory for Shock Wave and Detonation Physics Research Institute of Fluid Physics CAEP Mianyang 610059 China

Plate impact expeiments are conducted to investigate the dynamic behavior of alumina by using one stage light gas gun. A ve-locity interferometer system for reflectors (VISAR) is used to obtain Hugoniot elastic limit and the free surface velocity profile,which consists of an elastic wave followed immediately by a dispersive inelastic wave. the stress histories under different impact velocities are measured by in-material manganin gauges. Based on the experimental data a Hugoniot curve is fitted,which shows the compressive characteristics that alumina changes typically from elastic to "plastic" ,and under higher pressure it will be transferred to similar-fluid state. the turning point of the Hugoniot curve from a high pressure region to a low pressure region is about 11.4 GPa. the fracture process of alumina is simulated by way of finite element code. After the analysis of the fracture mechanism,the numerical results show an important role played by the nucleation and the growth of the cracks in the macro-scopic fracture of the alumina target. the numerical predictions of stress histories are compared with the experimental results,which indicates consistency between them.

关键词： plate impact experiment hugoniot curve fracture characteristics numerical simulation

Simulation of thermodynamics and Kinetics for KR Desulphurization

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Journal of Iron and Steel research International 2011年第S2期18卷 98-106页

作者： XU An-jun1, ZHANG Mao-lin2, ZHANG Hui-ning1, LI An-dong3.(1. School of Metallurgical and Ecological engineering, University of Science and Technology Beijing, Beijing 100083.china 2. Steel-Making and Continuous Casting engineering {3., Capital engineering and research Incorporation Limited, Beijing 100176,china 3. Stainless Steel Company, Baosteel Group, Shanghai 201900,china) Univ Sci & Technol Beijing Sch Met & Ecol Engn Beijing 100083 Peoples R China Capital Engn & Res Inc Ltd Steel Making & Continuous Casting Engn Inst Beijing 100176 Peoples R China Stainless Steel Co Baosteel Grp Shanghai 201900 Peoples R China

this paper seeks to optimize parameters, reduce the cost of desulphurization and the consumption of operation about KR pretreatment of hot metal at the Stainless Steel Company, Baosteel Group. Based on the theoretical analysis of physical chemistry in metallurgy, simulation experiments of the KR desulphurization of hot metal were conducted in a laboratory and the composition of the desulphurization was optimized, by means of chemical analysis, DSC, SEM and EDS. the water modeling displays the fluid flow characteristics of KR desulphurization. Combination of the techniques and production at the Stainless Steel Company, Baosteel Group, the optimized parameters of the process are put forward.

关键词： desulphurization of hot metal KR, desulphurization thermodynamics water model

Epithermal Ageing Mechanism of Gussasphalt

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Journal of Wuhan University of Technology(Materials Science) 2009年第3期24卷 466-470页

作者：郝增恒 School of Traffic Science and engineering Harbin Institute of Technology Chongqing Communications research and Design Instituts

the normal asphalt index test, DSR test, FTIR and the GPC distribution analysis of molecular weight on the extraction and recovery of asphalt of the gussasphalt, SMA extraction and recovery of asphalt and the rotary-thin-film-oven-aged asphalt above 240 ℃ were introduced. the results indicate the rutting factor and fatigue factor of the extraction and recovery of asphalt of the gussasphalt are greatly improved, and an obvious absorption peak of carbonyl and a further decrease of the SBS molecular weight of the gussasphalt are found.

关键词： gussasphalt epithermal ageing rheolagical performance fourier transforms infrared spectroscopy gel permeation chromatography