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science china(Physics,Mechanics & Astronomy) 2009年第6期52卷 909-918页

作者： shen fang1 & wu wangyi2 1 state key laboratory for space weather, center for space science and applied research, chinese academy of sciences, beijing 100190, china 2 state key laboratory of Turbulence and Complex Systems & Department of Mechanics and Engineering science, Peking University, beijing 100871, china 1. state key laboratory for space weather Center for Space Science and Applied Research Chinese Academy of Sciences Beijing 100190 China 2. state key laboratory of Turbulence and Complex Systems & Department of Mechanics and Engineering science Peking University Beijing 100871 China

Basic function method is developed to treat the incompressible viscous flow. Artificial compressibility coefficient, the technique of flux splitting method and the combination of central and upwind schemes are applied to construct the basic function scheme of trigonometric function type for solving three-dimensional incompressible Navier-Stokes equations numerically. To prove the method, flows in finite-length-pipe are calculated, the velocity and pressure distribution of which solved by our method quite coincide with the exact solutions of Poiseuille flow except in the areas of entrance and exit. After the method is proved elementary, the hemodynamics in two-and three-dimensional aneurysms is researched numerically by using the basic function method of trigonometric function type and unstructured grids generation technique. The distributions of velocity, pressure and shear force in steady flow of aneurysms are calculated, and the influence of the shape of the aneurysms on the hemodynamics is studied.

关键词： basic function unstructured grid aneurysm viscous incompressible flow artificial compressibility flux splitting

Anisotropic characteristics of electrical responses of fractured reservoir with multiple sets of fractures

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Petroleum science 2009年第2期6卷 127-138页

作者： shen Jinsong Su Benyu Guo Naichuan Department of Geophysics School of Resource and Information Technology China University of Petroleum Beijing 102249 China key laboratory of CNPC Geophysical Exploration China University of Petroleum Beijing 102249 China state key laboratory of Petroleum Resource and Prospecting China University of Petroleum Beijing 102249 China

In fractured reservoirs, the fractures not but also form the main flow channels which connect productivity of reservoirs. However, because of the only provide the storage space for hydrocarbons, the pores of the matrix, so fractures dominate the heterogeneity and randomness of the distribution of fractures, exploration and evaluation of fractured reservoirs is still one of the most difficult problems in the oil industry. In recent years, seismic anisotropy has been applied to the assessment of fractured formations, whereas electrical anisotropy which is more intense in fractured formations than seismic anisotropy has not been studied or used so extensively. In this study, fractured reservoir models which considered multiple sets of fractures with smooth and partly closed, rough surfaces were established based on the fractures and pore network, and the vertical and horizontal electrical resistivities were derived as a function of the matrix and fracture porosities according to Ohm＇s law. By using the anisotropic resistivity equations, variations of the electrical anisotropy of three types of fractured models under the conditions of free pressure and confining pressure were analyzed through the variations of the exerted pressure, matrix porosity, fracture aperture and formation water resistivity. The differences of the vertical and horizontal resistivities and the anisotropy between the connected and non-connected fractures were also analyzed. It is known from the simulated results that an increase of the confining pressure causes a decrease of electrical anisotropy because of the elasticity of the closed fractures and the decrease of the fracture aperture. For a fixed fracture porosity, the higher the matrix porosity, the weaker the electrical anisotropy in the rock formation.

关键词： Fractured reservoir partly closed fracture electrical anisotropy fracture roughness

Quantitative Analysis of CME Deflection in the Corona

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Quantitative Analysis of CME Deflection in the Corona

3-D MHD Simulation of the Evolution of Two CME Events Using Magnetized Plasma Blob Model

第十四届全国日地空间物理学术研讨会

作者： Bin Gui1,2 Chenglong shen1 Yuming Wang1, Pinzhong Ye1,2 Jiajia Liu1 Shui Wang1 and Xuepu Zhao3 (1 CAS key laboratory of Geospace Environment, Department of Geophysics & Planetary sciences, University of science & Technology of china, Hefei, Anhui 230026, china) (2 state key laboratory of space weather, center for space science and applied research, chinese academy of sciences, beijing, china) (3 W.W. Hansen Experimental Physics laboratory, Stanford University, Stanford, CA 94305, USA )

In this paper, ten CME events viewed by the STEREO twin spacecraft are analyzed to study the deflections of CMEs during their propagation in the corona. Based on the three-dimensional information of the CMEs derived by the graduated cylindrical shell （GCS） model [Thernisien et al., 2006], it is found that the propagation directions of eight CMEs had changed. By applying the theoretical method proposed by shen et al. [2011] to all the CMEs, we found that the deflections are consistent, in strength and direction, with the gradient of the magnetic energy density. There is a positive correlation between the deflection rate and the strength of the magnetic energy density gradient and a weak anti-correlation between the deflection rate and the CME speed. Our results suggest that the deflections of CMEs are mainly controlled by the background magnetic field and can be quantitatively described by the magnetic energy density gradient （MEDG） model.

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3-D MHD Simulation of the Evolution of Two CME Events Using ...

Synthesis,Crystal Structure, Thermal Decomposition and Sensitivity Properties of (AIM)(HTNR) and (AIM)(PA)

第十四届全国日地空间物理学术研讨会

作者： F. shen1 X. S. Feng1 Yuming Wang2 S. T. wu3 W. B. Song1 J. P. Guo1 and Y. F. Zhou1 (1 state key laboratory of space weather, National space science center, CAS, beijing 100190, china) (2 School of Earth & space sciences, University of science & Technology of china, Hefei, Anhui 230026, china) (3 center for space Plasma and Aeronomic research, the University of Alabama in Huntsville, Huntsville, AL 35899 USA)

A three-dimensional （3D） time-dependent, numerical magnetohydrodynamic （MHD） model is used to investigate the evolution and interaction of two CMEs in the nonhomogeneous ambient solar wind. The background solar wind is constructed based on the self-consistent source surface with observed line-of-sight of magnetic field and density from the source surface of 2.5 Rs to the Earth’s orbit （215 Rs） and beyond. The CMEs are simulated by means of a very simple flux rope model: a high-density, -velocity and -temperature magnetized plasma blob is superimposed on a steady state background solar wind with an initial launch direction. The dynamical interaction of a CME with the background solar wind flow between 2.5 and 220 Rs is investigated. We have chosen two well-defined CME events as the test cases. （1） the halo-CME event of 4-6 April 2000;（2） the two successive CMEs occurring on 2001 March 28 and forming a multiple magnetic cloud （multi-MC） in interplanetary space. In this validation study we find that this 3D MHD model, with the asynchronous and parallel time-marching method, the self-consistent source surface as initial-boundary conditions and the simple flux rope as CME model, provide a relatively satisfactory comparison with the ACE spacecraft observations at the L1 point, and can also reproduce and explain some of the general characters of the multiple magnetic clouds observed by satellite. Then, in order to understand the physical processes of the acceleration and deceleration of the CME propagation in the heliosphere, we also analyze the forces which caused the acceleration and deceleration in detail.

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Chemical research in chinese Universities 2012年第1期28卷 4-8页

作者： TANG Zhan, YANG Li, QIAO Xiao-jing, wu Bi-dong, ZHANG Tong-lai, ZHOU Zun-ning and YU Kai-bei state key laboratory of Explosion science and Technology, beijing Institute of Technology, beijing 100081, P. R. china beijing Inst Technol State Key Lab Explos Sci & Technol Beijing 100081 Peoples R China

Two new energetic compounds （AIM）（HTNR） and （AIM）（PA）（AIM=2-azidoimidazole, TNR=2,4,6-trini troresorcinol, PA=picric acid） have been prepared by AIM（2-azidoimidazolium） and TNR（2,4,6-trinitroresorcinol） or PA（picric acid） and characterized by elemental analysis and FTIR spectrum. Their crystal structures were determined by X-ray single-crystal diffraction analysis. The obtained results show that （AIM）（HTNR） crystal belongs to monoc linic, P21/c space group, a=1.1306（2） nm, b=0.70305（14） nm, c=1.7398（4） nm, β=106.91°, V=1.3231（5） nm3, Dc=1.778 g/cm3, Z=4, R1=0.0524, wR2[I 〉2σ（I）]=0.1067 and S=1.092 and （AIM）（PA） crystal belongs to monoclinic P21/c space group, a=0.80303（16） nm, b=0.81395（16） nm, c=2.0471（4） nm, β=93.93（3）°, V=1.3349（5） nm3, Dc=1.683 g/cm3, Z=4, R1=0.0784, wR2[I〉2σ（I）]=0.1814 and S=1.098. Both the compounds have electrostatic attraction and hy drogen bonds, which contribute to making the constructions more stable. The decomposition of the two compounds was studied via differential scanning calorimetry（DSC） and thermogravimetry-derivative thermogravimetry（TG-DTG） techniques at a heating rate of 10 oC/min, and the results show that both the compounds underwent one intensive exothermic decomposition stage. Sensitivity tests reveal that the title compounds were insensitive to friction and im pact and sensitive to flame and could be applied in potential pyrotechnics.

关键词： 2-Azidoimidazolium 2,4,6-Trinitroresorcinol Picric acid Crystal structure Thermal decomposition

Atomistic simulation of rare earth-transition intermetallic compounds derived from CaCu5 type

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Progress in Natural science:Materials International 2003年第5期 21-26页

作者： CHEN Nanxian, LU Yao, shen Jiang and wu Yu (1. Institute of applied Physics, beijing University of science and Technology, beijing 100083, china 2. Department of Physics, Ts-inghua University, beijing 100084, china) Institute of applied Physics，beijing University of science and Technology，beijing 100083，china Department of Physics，Tsinghua University，beijing 100084，china Institute of applied Physics，beijing University of science and Technology，beijing 100083，china

The rare earth(R)-transition metal(M) compounds are important subjects of new functional materials. In this paper, first we review the transformation relations between R-M compounds (Rn-mM5n + 2m) derived from CaCu5 type structure, and discuss their validity and limitations. Then we calculate the lattice parameters and crystal structures of five binary compounds, SmFe5, Sm2Fe17 (H), Sm2Fe17(R), SmFe12(t), and Sm3Fe29 by energy minimization. With above results, we get the vector transformation matrix in reciprocal space in comparison with the traditional transformation matrix and analyze the reason for their similarity and difference. Finally, we discuss the stable effect of the third elements Cr, Ti to Sm3Fe29- The third elements also change the lattice parameters and the materials X-rays diffraction pattern. The tradition matrix cannot reflect these differences.

关键词： R-M compounds derived from CaCus type structure transformation relation interatomic potential.

SKIP: an efficient search mechanism in unstructured P2P networks

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The Journal of china Universities of Posts and Telecommunications 2010年第5期17卷 64-71页

作者： shen Wen-wu SU Sen SHUANG Kai YANG fang-chun state key laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing 100876 China

Search efficiency and accuracy of resource are important considerations for search algorithm in peer-to-peer （P2P） *** search algorithms use flooding among neighbor nodes to search relevant ***,this usually causes great amount of redundant messages,which results in high search costs and low search *** this paper,we use vector space model （VSM） and relevance ranking algorithms to construct overlay network,and a novel search mechanism search with K-iteration preference （SKIP） based on semantic group for P2P networks is proposed to efficiently solve these *** key idea of SKIP is to reorder the semantic neighbors of nodes according to relevant scores and to utilize preference selection during the process of *** analysis and implement the scheme and reveal that the SKIP provides a low overhead on topology maintenance,which can be effectively used in P2P searching and verify it outperformance in higher precision and lower search cost by comparing with current semantic-based searching mechanism gnutella-like efficient searching system （GES）.

关键词： K-iteration preference SKIP P2P networks

Structural transition,electric transport,and electronic structures in the compressed trilayer nickelate La_(4)Ni_(3)O_(10)

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science china(Physics,Mechanics & Astronomy) 2024年第11期67卷 9-15页

作者： Jingyuan Li Cui-Qun Chen Chaoxin Huang Yifeng Han Mengwu Huo Xing Huang Peiyue Ma Zhengyang Qiu Junfeng Chen Xunwu Hu Lan Chen Tao Xie Bing shen Hualei Sun Dao-Xin Yao Meng Wang center for Neutron science and Technology Guangdong Provincial Key Laboratory of Magnetoelectric Physics and DevicesSchool of PhysicsSun Yat-sen UniversityGuangzhou 510275China center for Materials of the Universe School of Molecular SciencesArizona State UniversityTempe 85287USA School of sciences Sun Yat-sen UniversityShenzhen 518107China

Atomic structure and electronic band structure are fundamental properties for understanding the mechanism of superconductivity. Motivated by the discovery of pressure-induced high-temperature superconductivity at 80 K in the bilayer Ruddlesden-Popper nickelate La_(3)Ni_(2)O_(7), the atomic structure and electronic band structure of the trilayer nickelate La_(4)Ni_(3)O_(10) under pressure up to 44.3 GPa are investigated. A structural transition from the monoclinic P2_(1)/a space group to the tetragonal I4/mmm around 12.6-13.4 GPa is identified, accompanied by a drop of resistance below 7 K. Density functional theory calculations suggest that the bonding state of Ni 3d_(z^(2)) orbital rises and crosses the Fermi level at high pressures, which may give rise to possible superconductivity observed in resistance under pressure in La_(4)Ni_(3)O_(10). The trilayer nickelate La_(4)Ni_(3)O_(10) shows some similarities with the bilayer La_(3)Ni_(2)O_(7) and has unique properties, providing a new platform to investigate the underlying mechanism of superconductivity in nickelates.

关键词： La_(4)Ni_(3)O_(10) high pressure synchrotron X-ray diffraction structural transition DFT calculations

河南省商城县2种动物发热伴血小板减少综合征病毒感染情况的调查研究

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中华疾病控制杂志 2024年第1期28卷 83-91页

作者：刘万双陈浩荣代科蒋宝贵陈津津田珅吴家红刘玮方立群贵州医科大学公共卫生学院流行病与卫生统计学系贵阳550025 北京化工大学生命科学与技术学院制药工程学系北京100029 军事医学研究院微生物流行病研究所病原微生物生物安全国家重点实验室北京100071 广州医科大学公共卫生学院流行病与卫生统计学系广州511436

目的通过开展发热伴血小板减少综合征(severe fever with thrombocytopenia syndrome,SFTS)自然疫源地动物宿主感染新布尼亚病毒(severe fever with thrombocytopenia syndrome virus,SFTSV)的调查研究,明确SFTS自然疫源地SFTSV的传播风险与影响因素,为SFTS的针对性防控提供科学依据。方法采用卫星定位技术连续跟踪商城县邱湾村、平塘村和龙头桥村3个村庄部分村民家养狗日常活动轨迹2周并采集血清样本,使用间接荧光抗体试验(indirect immunofluorescence assay,IFA)法检测家养狗血清SFTSV⁃IgG抗体,使用logistic回归分析模型分析影响家养狗感染SFTSV的潜在环境影响因素;采用夹(笼)夜法和粘鼠板法对家养狗活动区域内的啮齿动物及小型哺乳动物种群进行密度调查,针对保守基因进行PCR种类鉴定,并采用荧光PCR和酶联免疫吸附试验(enzyme linked immunosorbent assay,ELISA)方法检测啮齿动物及小型哺乳动物SFTSV感染情况。结果通过卫星定位共追踪26条家养狗的日常活动范围信息,采集37条家养狗52份血清,SFTSV⁃IgG抗体总阳性率为59.46%;共捕获啮齿动物及小型哺乳动物419只,优势种为黄胸鼠、小家鼠、黑线姬鼠,未有SFTSV阳性标本检出;家养狗活动中心离主干道路距离远和到过林地的频次多是感染SFTSV的危险因素,家养狗活动中心离林地距离远是感染SFTSV的保护因素。结论商城县家养狗SFTSV抗体阳性率较高,感染SFTSV与生态环境相关,建议进一步扩大家养动物的种类,开展SFTSV感染情况的研究;啮齿动物的SFTSV感染率低,在SFTSV自然循环过程中的作用需进一步调查。

关键词：新布尼亚病毒蜱传疾病啮齿动物血清学危险因素血小板减少综合征发热

The heating of the solar transition region

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research in Astronomy and Astrophysics 2010年第6期10卷 529-532页

作者： Wen-Bin Song Xue-Shang Feng fang shen SIGMA weather Group State Key Laboratory of Space Weather Center for Space Science and Applied Research Chinese Academy of Sciences Beijing 100190 China

The temperature curve in the solar chromosphere has puzzled astronomers for a long time. Referring to the structure of supergranular cells, we propose an inductive heating model. It mainly includes the following three steps. （1） A small-scale dynamo exists in the supergranulation and produces alternating small-scale magnetic fluxes; （2） The supergranular flow distributes these small-scale fluxes according to a regular pattern; （3） A skin effect occurs in the alternating and regularly-distributed magnetic fields. The induced current is concentrated near the transition region and heats it by resistive dissipation.

关键词： Sun transition region -- Sun granulation