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

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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,chinese academy of sciences key {3. of Advanced energy and Power,chinese academy of sciences (Institute of Engineering Thermophysics),Beijing,100190,China Research Center for Clean energy and Power Chinese Academy of Sciences Beijing China key laboratory of Advanced energy 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

Exploration of combined adjustment laws about IGV,stator and rotational speed in off-design conditions in an axial compressor

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中国科学：技术科学英文版 2010年第4期53卷 969-975页

作者： HU YanMing1,2 & NIE ChaoQun1 1 key laboratory of Advanced energy and Power Technology,Institute of Engineeting Thermophysics,{3. {4. of Science,Beijing {4.,China 2 Graduate School of chinese academy of sciences,Beijing {4.,China 1. key laboratory of Advanced energy and Power Technology Institute of Engineeting Thermophysics Chinese Academy of Science Beijing 100190 China2. Graduate School of Chinese Academy of Sciences Beijing 100190 China

Experimental investigations are performed in a three-stage low-speed axial compressor with variable inlet guide vanes(IGV) and adjustable *** characteristics of the compressor,especially the efficiency and stall margin,are analyzed in design and off-design operation conditions by adjusting stagger angles of IGV and stators as well as changing the rotational *** experimental results show that the off-design performance of the multistage axial compressor is improved by restaggering of IGV and stators related to rotational *** the background of engineering applications,digital signal processing(DSP) technique is used to realize online adjustment of stagger angles according to the corresponding relations between incidence angles of rotor and rotational speed.

关键词： axial compressor IGV surge DSP techniques off-design

Narrow line Seyfert 1 galaxies: where are the broad line regions?

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Science China(Physics,Mechanics & Astronomy) 2010年第12期53卷 2307-2311,2339-2343页

作者： MAO WeiMing 1,2,3., HU Chen 2 , WANG JianMin 2 , BIAN WeiHao 4., ZHANG Shu 2 & ZHAO Gang 1 1 key laboratory of Optical Astronomy, National Astronomical Observatories, chinese academy of sciences, Beijing 100012, China 2 key laboratory for Particle Astrophysics, Institute of High energy Physics, chinese academy of sciences, Beijing 10004., China 3.Graduate University of the chinese academy of sciences, Beijing 10004., China 4.Department of Physics, Nanjing Normal University, Nanjing 210011, China 1. key laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China2. Key Laboratory for Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China3. Graduate University of the Chinese Academy of Sciences Beijing 100049 China4. Department of Physics Nanjing Normal University Nanjing 210011 China

A sample consisting of 211 narrow line Seyfert 1 galaxies (NLS1s) with high quality spectra from the Sloan Digital Sky Survey (SDSS) is selected to explore where broad line regions are in these objects. We find that the Hβ profile can be fitted well by three (narrow, intermediate and broad) Gaussian components, and the FWHM ratios of the broad to the intermediate components hold a constant of 3.0 roughly for the entire sample. If the broad components originate from the region scaled by the well-determined Hβ reverberation mapping relation, we find that the intermediate components originate from the inner edge of the torus, which is scaled by dust K-band reverberation. We find that the IC and the BC are strongly linked dynamically, but the relation of their covering factors is much more relaxed, implying that both regions are clumpy.

关键词： black hole physics galaxies: evolution quasars: general

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

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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 High Temperature Gas Dynamics,Institute of Mechanics,chinese academy of sciences,Beijing {3.,China 2 The State key laboratory of Nonlinear Mechanics,Institute of Mechanics,chinese academy of sciences,Beijing {3.,China 1. key laboratory of High Temperature Gas Dynamics Institute of Mechanics Chinese Academy of Sciences Beijing 100190 China2. The State Key Laboratory of Nonlinear Mechanics Institute of Mechanics Chinese Academy of Sciences Beijing 100190 China

A direct numerical simulation of the shock/turbulent boundary layer interaction flow in a supersonic 24.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

Geometry of Broad Line Regions of Active Galactic Nuclei

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chinese Journal of Astronomy and Astrophysics 2008年第1期8卷 50-62页

作者： Xiao-Rong Lü1 key laboratory for Particle Astrophysics, Institute of High energy Physics, {3., Beijing 10004. 2 Graduate School of {3., Beijing 10004. key laboratory for Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 and Graduate School of chinese academy of sciences Beijing 100049

It has long remained an open question as to the geometry of the broad line region （BLR） in active galactic nuclei （AGNs）. The reverberation mapping technique which measures the response of the broad emission lines to the ionizing continuum, when combined with multiwavelength continuum fitted by sophisticated accretion disks, provides a way of probing the BLR geometry. We analyze a sample of 3. AGNs, which have been monitored by the reverberation mapping campaign. In view of energy budget, the reverberation-based BH masses are found to be in agreement with those obtained by accretion disk models in two thirds of the present sample while the reverberation mapping methods underestimate the BH masses in about one third of objects, as also suggested by CoUin et al. in a recent work. We point out that there are obviously two kinds of BLR geometry, which are strongly dependent on the Eddington ratio, and separated by the value LBol/LEdd - 0.1. These results prefer a scenario of the disk and wind configuration of the BLR and identify the Eddington ratio as the physical driver regulating the wind in the BLR.

关键词： accretion, accretion disks - galaxies active - galaxies Seyfert - quasars general

Unsteady Numerical Simulation of Hot Streak/Blades Interaction and Film Cooling

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Journal of Thermal Science 2010年第5期19卷 402-409页

作者： Weilin Yi,Lucheng Ji and Yunhan Xiao Research Center for energy and Power,chinese academy of sciences,Beijing,China key {3. of Advanced energy and Power,chinese academy of sciences,(Institute of Engineering Thermophysics),Beijing,China P.O.Box 2706,Beijing 100190,China Research Center for energy and Power Chinese Academy of Sciences Beijing China key laboratory of Advanced energy and Power Chinese Academy of Sciences (Institute of Engineering Thermophysics) Beijing China Beijing China

Deeply research on management and application of hot streak is an important way to breakthrough technique obstacle of aero engine hot *** method is a useful instrument to investigate the correlative *** the paper developed independently three dimensional unsteady parallel computational code-MpiTurbo based on Fortran 90 and MPI at Linux operating *** unsteady numerical simulation was carried out to investigate impacts of the factors,which included circumferential locations of hot streak and clocking positions of blade rows,on the thermal environment of a 1+1 counter-rotating *** results clearly indicated that clocking positions of hot streak/blade row and blade row/blade row had great influence on the time-averaged temperature distribution of the third blade ***,it can be effective for improving thermal environment of turbine to optimize blade parameters and clocking *** film cooling layout was designed by the repetitious steady simulation based on source term *** the flow structure detail was given by the unsteady simulation.

关键词： hot streak turbine parallel computation film cooling

Compression behavior of Zr_(4.)Ti_(14.Cu_(12.5)Ni_(10)Be_(22.5) bulk metallic glass up to 24.GPa

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Science China(Physics,Mechanics & Astronomy) 2005年第3期48卷 319-324页

作者： LI Gong 1, 2 , ZHAN Zaiji 2 , LIU Jing 3., YUN Jinku 1 , SUN Liling 2 , LIU Riping 1 , ZHANG Jun 2 & WANG Wenkui 1, 2 1. key laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004. China 2. Center for Condensed Matter Physics, Institute of Physics, chinese academy of sciences, Beijing 100080, China 3. BSRF, Institute of High {3. Physics, chinese academy of sciences, Beijing 10003., China 1. key laboratory of Metastable Materials Science and Technology Yanshan University 066004 Qinhuangdao China 2. Center for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences 100080 Beijing China 3. BSRF Institute of High Energy Physics Chinese Academy of Sciences 100039 Beijing China

The compression of a Zr4.Ti14.u12.5Ni10Be22.5 bulk metallic glass (BMG) is investigated at room temperature up to 24.GPa using in-situ high pressure energy dispersive X-ray diffraction with a synchrotron radiation source. The pressure-induced structural relaxation is exhibited. It is found that below about 8 GPa, the existence of excess free volume contributes to the rapid structural relaxation, which gives rise to the rapid volumetric change, and the structural relaxation results in the structural stiffness under higher pressure.

关键词： bulk metallic glass, high pressure, structural relaxation, synchrotron radiation.

Ambient noise near the sea-route

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Science China(Physics,Mechanics & Astronomy) 2009年第1期52卷 40-45页

作者： HE Li1,2, LI ZhengLin1,3.& PENG ZhaoHui1 1 National laboratory of Acoustics, Institute of Acoustics, chinese academy of sciences, Beijing 100190, China 2 Institute of Geology and Geophysics, chinese academy of sciences, Beijing 100029, China 3.NanHai laboratory of Acoustics, Institute of Acoustics, chinese academy of sciences, Haikou 570206, China National laboratory of Acoustics Institute of Acoustics Chinese Academy of Sciences Beijing 100190 China Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China NanHai laboratory of Acoustics Institute of Acoustics Chinese Academy of Sciences Haikou 570206 China

Ambient noise data measured in an experiment conducted in shallow water near a sea-route were analyzed. It was observed that, at low frequency, the horizontal correlation has an obvious difference from that predicted by the classical ambient noise model. The theoretical analyses show that this phenomenon is caused by wind noise together with the discrete shipping noise nearby. An ambient noise model was proposed to include the effects caused by both the noise sources. Data measured at different times verify that the proposed model can be used to forecast the ambient noise field in shallow water near the sea-route.

关键词： ambient noise model horizontal correlation discrete ships

A 12-bit multichannel ADC for pixel detectors in particle physics and nuclear imaging

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Science China(Technological sciences) 2010年第5期53卷 1208-1214页

作者： WEI Wei1,2,3.WANG Zheng1,3.& ZHAO JingWei1,3.1 Institute of High energy Physics,{4.,Beijing 10004.,China 2 Graduate University of {4.,Beijing 10004.,China 3.{3. Lab of Nuclear Detection Technology and Nuclear Electronics of {4.,Beijing 10004.,China 1. Institute of High energy Physics Chinese Academy of Sciences Beijing 100049 China2. Graduate University of Chinese Academy of Sciences Beijing 100049 China3. Key Lab of Nuclear Detection Technology and Nuclear Electronics of Chinese Academy of Sciences Beijing 100049 China

Modern pixel detectors in nuclear and particle physics experiments and also in nuclear imaging,starve for highly integrated application specified integrated circuit(ASIC),whereas in China the study of ASIC still stays far away from practical *** lack of ASIC strictly limits the research and development of domestic high energy physics field.A 12-bit multichannel ADC designed for high density readout is introduced as a major candidate for solution.A precise model is discussed and the simulation fully agrees with the model,which indicates a key principle of *** is performed according to the given rule,and novel layout techniques are carried *** results in all aspects are also obtained,showing an excellent real performance,which satisfies the practical requirement.

关键词： application specified integrated circuit high density readout Wilkinson ADC multi-channel ADC