检索结果-南通市图书馆

Research of the Gas-solid Flow Character Based on the DEM Method

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2011年第6期20卷 521-526页

作者： Xueyao Wang and Yunhan xiao Research Center for Clean energy and Power,{2. academy of sciences key laboratory of Advanced energy and Power,{2. academy of sciences (institute of Engineering Thermo{12.),Beijing,100190,China Research Center for Clean energy and Power Chinese Academy of Sciences Beijing China key laboratory of Advanced {2. and Power Chinese Academy of Sciences (Institute of Engineering Thermophysics) Beijing China

Numerical simulation of gas-solid flow behaviors in a rectangular fluidized bed is carried out three dimensionally by the discrete element method (DEM).Euler method and lagrange method are employed to deal with the gas phase and solid phase *** collided force among particles,striking force between particle and wall,drag force,gravity,Magnus lift force and Saffman lift force are considered when establishing the mathematic ***-sphere model is used to describe the collision of *** addition,the Euler method is also used for modeling the solid phase to compare with the results of *** flow patterns,particle mean velocities,particles' diffusion and pressure drop of the bed under typical operating conditions are *** results show that the DEM method can describe the detailed information among particles,while the Euler-Euler method cannot capture the micro-scale *** matter which method is used,the diffusion of particles increases with the increase of gas *** the gathering and crushing of particles cannot be simulated,so the energy loss of particles' collision cannot be calculated and the diffusion by using the Euler-Euler method is *** addition,it is shown by DEM method,with strengthening of the carrying capacity,more and more particles can be schlepped upward and the dense suspension upflow pattern can be ***,the results given by the Euler-Euler method are not consistent with the real situation.

关键词： DEM gas-solid flow numerical simulation

The time lag spectrum of Cir X-1 on its normal branch

在线全文

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2010年第S1期53卷 60-63页

作者： QU Jinlu1,lU Yu1,2.DING GuoQiang3,ZHANG Fan1,lEI YaJuan1 & lI ZhiBing1 1 key laboratory for {2. astrophysics,institute of high energy physics,chinese academy of sciences,Beijing 100049,China 2.Graduate University of{12.,Beijing 100049,China 3 Urumqi Observatory,NAOC Urumqi 830011,China key laboratory for {2. astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing China Graduate University of chinese academy of sciences Beijing China Urumqi Observatory NAOC Urumqi China

In the radiation-hydrodynamics model,the time lag and fractional root-mean-squared(rms) amplitude as a function of emitted photon energy should show a minimum on the normal branch *** has been seen in the Z-sources Cyg X-2.and GX ***,using the observations from the Rossi X-ray Timing Explorer(RXTE),we study the energy dependence of normal branch QPOs in the peculiar Z-source Cir *** discuss the results in the context of radiation-hydrodynamics and the Comptonization model.

关键词： Cir X-1 temporal variability QPO time lag

Observation constraints of the hard X-ray modulation telescope HXMT

在线全文

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2010年第S1期53卷 31-35页

作者： lU Yu1,2.ZHANG WenZhao3,QU Jinlu1,SONG liMing1,GAO Jian3,ZHANG HongMei4 & OU Ge4 1 key laboratory of {2. astrophysics,institute of high energy physics,chinese academy of sciences,Beijing 100049,China 2.Graduate University of{12.,Beijing 100049,China 3 Department of Astronomy,Beijing Normal University,Beijing 100875,China 4 Computing Center,institute of high energy physics,chinese academy of sciences,Beijing 100049,China key laboratory of {2. astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing China Graduate University of chinese academy of sciences Beijing China Department of Astronomy Beijing Normal University Beijing China Computing Center Institute of High Energy Physics Chinese Academy of Sciences Beijing China

The hard X-ray modulation telescope HXMT is a low orbit X-ray space telescope whose main science goals are to accomplish a hard X-ray all sky survey and to study timing and spectral characteristics of X-ray *** has three kinds of science instruments:the high energy X-ray detector(HE),the medium energy X-ray detector(ME) and the low energy X-ray detector(lE).The observation schedule of HXMT is a key to achieving the science goal of HXMT,and the analysis of the observation constraints is one of the first tasks in making the observation *** paper analyzes how the observation constraints influence the sky visibility and the visible time distribution of X-ray sources and discusses the schedule strategy with regard to the observation constraints.

关键词： HXMT observation constraints sky visibility

Direct numerical simulation of shock/turbulent boundary layer interaction in a supersonic compression ramp

在线全文

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2010年第9期53卷 1651-1658页

作者： lI Xinliang1,FU DeXun2.MA YanWen2.& lIANG Xian1 1 key laboratory of {2. Temperature Gas Dynamics,institute of Mechanics,chinese academy of sciences,Beijing 100190,China 2.The State key laboratory of Nonlinear Mechanics,institute of Mechanics,chinese academy of sciences,Beijing 100190,China key laboratory of {2. Temperature Gas Dynamics Institute of Mechanics Chinese Academy of Sciences Beijing China The State key laboratory of Nonlinear Mechanics Institute of Mechanics Chinese Academy of Sciences Beijing China

A direct numerical simulation of the shock/turbulent boundary layer interaction flow in a supersonic 2.-degree compression ramp is conducted with the free stream Mach number *** blow-and-suction disturbance in the upstream wall boundary is used to trigger the *** the mean wall pressure and the velocity profiles agree with those of the experimental data,which validates the *** turbulent kinetic energy budget in the separation region is *** show that the turbulent production term increases fast in the separation region,while the turbulent dissipation term reaches its peak in the near-wall *** turbulent transport term contributes to the balance of the turbulent conduction and turbulent *** on the analysis of instantaneous pressure in the downstream region of the mean shock and that in the separation bubble,the authors suggest that the low frequency oscillation of the shock is not caused by the upstream turbulent disturbance,but rather the instability of separation bubble.

关键词： compression ramp shock/turbulent boundary layer interaction direct numerical simulation shock oscillation

Correlation between the charge radii difference in mirror partner nuclei and thesymmetry energy slope

在线全文

学校读者我要写书评

暂无评论

chinese physics C 2024年第8期48卷 177-184页

作者： xiao-rong Ma Shuai Sun rong An li-Gang Cao School of physics Ningxia UniversityYinchuan 750021China key laboratory of Beam Technology of Ministry of Education College of Nuclear Science and TechnologyBeijing Normal UniversityBeijing 100875China key laboratory of Beam Technology of Ministry of Education Institute of Radiation TechnologyBeijing Academy of Science and TechnologyBeijing 100875China

A correlation between the charge radii difference of mirror partner nucleiΔR_(ch) and the slope parameter l of symmetry energy has been built to ascertain the equation of state of isospin asymmetric nuclear *** this work,the influences of pairing correlations and isoscalar compression modulus on theΔRch are systematically investigated based on the Skyrme energy density functional *** calculated results suggest that the linear correlation betweenΔR_(ch) and l is decreased by the surface pairing *** slope parameter deduced from the difference of charge radii of mirror-pair nuclei ^(32.Ar-^(32.Si,^(36)Ca-^(36)S,^(38)Ca-^(38)Ar,and ^(54)Ni-^(54)Fe falls into the range of l=42.57−50.64 MeV,that is,the rather soft equation of state of asymmetric nuclear ***,the range of the slope parameter can also be influenced by the effective forces classified by various isoscalar incompressibility coefficients.

关键词： symmetry energy charge radius mirror-pair nuclei slope parameter

Heavy ion reactions around the Coulomb barrier

在线全文

学校读者我要写书评

暂无评论

中国科学：物理学、力学、天文学英文版 2011年第S1期54卷 6-13页

作者： ZHANG HuanQiao1, lIN ChengJian1, JIA HuiMing1, ZHANG Chunlei1,2. ZHANG Gaolong1,3, YANG Feng1, lIU ZuHua1, AN GuangPeng1, WU ZhenDong1, XU XinXing1 & JIA Fei1 1 China institute of Atomic energy, P. O. Box 2.5(10), Beijing 102.13, China 2.{2. astrophysics Center, institute of high energy physics, chinese academy of sciences, Beijing 100039, China 3 School of physics and Nuclear energy Engineering, Beihang University, Beijing 100191, China China institute of Atomic energy Beijing China particle astrophysics Center Institute of High Energy Physics Chinese Academy of Sciences Beijing China School of physics and Nuclear energy Engineering Beihang University Beijing China

The angular distributions of fission fragments for the 32.+184W reaction near Coulomb barrier energies are measured. The ex perimental fission excitation function is obtained. The measured fission cross sections are decomposed into fusion-fission, quasi-fission and fast fission contributions by the dinuclear system (DNS) model. The hindrance to completing fusion both at small and large collision energies is explained. The fusion excitation functions of 32.+90,96Zr in an energy range from above to below the Coulomb barrier are measured and analyzed within a semi-classical model. The obvious effect of positive Q-value multi-neutron transfers on the sub-barrier fusion enhancement is observed in the 32.+96Zr system. In addition, the excitation functions of quasi-elastic scattering at a backward angle have been measured with high precision for the systems of 16O+2.8Pb, 196Pt, 184W, and 154,152.m at energies well below the Coulomb barrier. Considering the deformed coupling effects, the extracted diffuseness parameters are close to the values extracted from the systematic analysis of elastic and inelastic scattering data. The elastic scattering angular distribution of 17F+12. at 60 MeV is measured and calculated by using the continuum-discretized coupled-channels (CDCC) approach. It is found that the diffuseness parameter of the real part of core-target potential has to be increased by 2.% to reproduce the experimental result, which corresponds to an increment of potential depth at the surface re gion. The breakup cross section and the coupling between breakup and elastic scattering are small.

关键词： fusion-fission quasi-fission fusion hindrance fusion enhancement surface diffuseness parameter exotic nuclei

Testing local realism in P → VV decays

在线全文

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2010年第5期53卷 870-875页

作者： lI Junli1 & QIAO CongFeng1,2.1Department of physics,Graduate University of chinese academy of sciences,Beijing {2.,China 2.heoretical physics Center for Science Facilities(TPCSF),chinese academy of sciences,Beijing {2.,China Department of physics Graduate University of Chinese Academy of Sciences Beijing China Theoretical physics Center for Science Facilities (TPCSF) Chinese Academy of Sciences Beijing China

It was found that the vector meson pair from the pseudoscalar decays can form an entangled *** this work we give out detailed explanations on the polarization correlation of the two entangled vector *** is demonstrated that an experimental test of the Clauser-Horne inequality can be carried out through measuring the azimuthal distribution of four pseudoscalars in the cascade decay ηc→ VV →(PP)(PP),and the measurement of this process is feasible with the current running experiments in tau-charm ***,a brief discussion on the polarization correlation of the two vector mesons from B → VV decays is also presented.

关键词： nonlocality test high energy experiment meson decays

Correlation of Behavior Changes and BOlD Signal in Alzheimer-like Rat Model

在线全文

学校读者我要写书评

暂无评论

Acta Biochimica et Biophysica Sinica 2004年第12期36卷 803-810页

作者： Zheng-Hui HU#, xiao-Chuan WANG1#, li-Yun lI3, Mai-li lIU3, rong lIU1, Zhiqun lING1, Qing TIAN1, xiao-Wei TANG, Yi-Gen WU2., and Jian-Zhi WANG1* Department of physics and Bio-X disciplinary laboratory, Zhejiang University, Hangzhou 31002.,China 1 Department of Pathophysiology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China 2.5} of high energy physics and key laboratory of Nuclear Analysis Techniques, chinese academy of sciences, P.O. Box 918, Beijing 100039, China 3Wuhan institute of physics and Mathematics, State key laboratory of Magnetic Resonance and Atomic and Molecular physics, chinese academy of sciences, Wuhan 430071, China Department of physics and Bio-X disciplinary laboratory Zhejiang UniversityHangzhou 310027China Department of Pathophysiology Tongji Medical College Huazhong University of Science and TechnologyWuhan 430030 China Wuhan institute of physics and Mathematics State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Chinese Academy of SciencesWuhan 430071 China institute of high {2. physics and key laboratory of Nuclear Analysis Techniques Chinese Academy of SciencesP.O. Box 918 Beijing 100039 China

To explore a potential means for the early diagnosis of Alzheimer disease, we studied the relationship of resting T2. signal and tau hyperphosphorylation/spatial memory deficit. The rat model with tau hyperphosphorylation and spatial memory deficit was established by bilateral hippocampi injection of isoproterenol (IP). Then, the correlative alteration between resting T2. signal and spatial memory retention was assessed with blood oxygenation level dependent (BOlD) functional magnetic resonance imaging (fMRI) study and Morris Water Maze test, and Western blot was employed to confirm tau hyperphosphorylation. The analysis showed following results. (1) Tau phosphorylation at Ser396/Ser404 and Ser199/Ser2.2.was signifi- cantly increased in IP-injected rats as detected by PHF-1 and tau-1, respectively. (2. An AD-like spatial memory retention disturbance was induced at 2. h after isoproterenol injection. (3) A sensitivity threshold of resting T2. signal intensity, which separated the IP-treated rats from vehicle control, was obtained by applying linear regression analysis, and an estimated sensitivity statistical threshold was at 32.62. These results suggest that resting T2. signal may serve as a noninvasive quantitative marker in predicting AD-like spatial memory deficits and tau hyperphosphorylation.

关键词： Alzheimer disease (AD) functional magnetic resonance imaging (fMRI) isoproterenol (IP) Morris Water Maze diagnosis

Creep-Resistant Covalent Adaptable Networks with Excellent SelfHealing and Reprocessing Performance via Phase-locked Dynamic Covalent Benzopyrazole-Urea Bonds

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

chinese Journal of Polymer Science 2024年第10期42卷 1545-1556,I0013页

作者： Miao Xie xiao-rong Wang Zhan-Hua Wang He-Sheng Xia State key laboratory of Polymer Materials Engineering Polymer Research InstituteSichuan UniversityChengdu610065China School of Petrochemical Engineering Liaoning Petrochemical UniversityFushun113001China

Covalent adaptive networks(CANs)are capable of undergoing segment rearrangement after being heated,which endows the materials with excellent self-healing and reprocessing performance,providing an efficient solution to the environment pollution caused by the plastic *** main challenge remains in developing CANs with both excellent reprocessing performance and creep-resistance *** this study,a series of CANs containing dynamic covalent benzopyrazole-urea bonds were developed based on the addition reaction between benzopyrazole and isocyanate *** calculation confirmed that relatively low dissociation energy is obtained through undergoing a five-member ring transition state,confirming excellent dynamic property of the benzopyrazole-urea *** verified by the FTIR results,this nice dynamic property can be well maintained after incorporating the benzopyrazole-urea bonds into polymer *** self-healing and reprocessing performance is observed by the 3-ABP/PDMS elastomers owing to the dynamic benzopyrazole-urea *** separation induced by the aggregation of the hard segments locked the benzopyrazole-urea bonds,which also makes the elastomers display excellent creep-resistance *** hard phase locking strategy provides an efficient approach to design CANs materials with both excellent reprocessing and creep-resistance performance.

关键词： Covalent adaptive networks Self-healing polymer Dynamic covalent bond