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A one-dimensional heat transfer model of the Antarctic Ice Sheet and modeling of snow temperatures at Dome A, the summit of Antarctic Plateau

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Science china Earth sciences 2010年第5期53卷 763-772页

作者： CHEN BaiLian1,3, ZHANG RenHe2. SUN ShuFen1, BIAN LinGen2. XIAO CunDe4,2.& ZHANG TingJun5 1 institute of Atmospheric physics, {2., Beijing 10002., china 2.chinese academy of Meteorological sciences, Beijing 100081, china 3 Graduate University of {2., Beijing 100049, china 4 Cold and Arid Regions Environmental and Engineering Research institute, {2., Lanzhou 730000, china 5 The National Snow and Ice Data Center, University of Colorado, Boulder, CO 80309-0449, USA 1. institute of Atmospheric physics Chinese Academy of Sciences Beijing 100029 China3. Graduate University of Chinese Academy of Sciences Beijing 100049 China2. Chinese Academy of Meteorological Sciences Beijing 100081 China4. Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China5. The National Snow and Ice Data Center University of Colorado Boulder CO 80309-0449 USA

A vertical one-dimensional numerical model for heat transferring within the near-surface snow layer of the Antarctic Ice Sheet was developed based on simplified parameterizations of associated physical processes for the atmosphere, radiation, and snow/ice systems. Using the meteorological data of an automatic weather station (AWS) at Dome A (80°2.′S, 70°2.′E), we applied the model to simulate the seasonal temperature variation within a depth of 2. m. Comparison of modeled results with observed snow temperatures at 4 measurement depths (0.1, 1, 3, 10 m) shows good agreement and consistent seasonal variations. The model results reveal the vertical temperature structure within the near-surface snow layer and its seasonal variance with more details than those by limited measurements. Analyses on the model outputs of the surface energy fluxes show that: 1) the surface energy balance at Dome A is characterized by the compensation between negative net radiation and the positive sensible fluxes, and 2. the sensible heat is on average transported from the atmosphere to the snow, and has an evident increase in spring. The results are considered well representative for the {2.est interior Antarctic Plateau.

关键词： Antarctic Ice Sheet near-surface layer energy transfer numerical model

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

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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 Particle Astrophysics,institute of {2. energy physics,chinese academy of sciences,Beijing 100049,china 2.Graduate University of chinese academy of sciences,Beijing 100049,china 3 Urumqi Observatory,NAOC Urumqi 830011,china 1. Key Laboratory for Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China2. Graduate University of Chinese Academy of Sciences Beijing 100049 China3. Urumqi Observatory NAOC Urumqi 830011 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

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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,{2.,Beijing 100190,china 2.The State Key Laboratory of Nonlinear Mechanics,institute of Mechanics,{2.,Beijing 100190,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 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

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In situ study on dendrite growth of metallic alloy by a synchrotron radiation imaging technology

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Science china(Technological sciences) 2010年第5期53卷 1278-1284页

作者： WANG TongMin1,XU JingJing1,LI Jun1,HUANG WanXia2.LIU ShengChu1 & LI TingJu1 1 School of Materials Science and Engineering,Dalian University of Technology,Dalian 11602.,china 2.institute of {2. energy physics,chinese academy of sciences,Beijing 100039,china 1. School of Materials Science and Engineering Dalian University of Technology Dalian 116024 China2. Institute of High Energy Physics Chinese Academy of Sciences Beijing 100039 China

This study was trying to observe the real-time dendrite growth of Sn-Bi and Sn-Pb binary alloys by a synchrotron radiation imaging *** imaging system includes an intense and high brightness synchrotron radiation source,a high-resolution and fast-readout charge coupled device camera,an alloy sample and a Bridgman solidification *** imaging experiments were done at Beijing Synchrotron Radiation Facility with an updated synchrotron radiation imaging technique,diffraction-enhanced imaging,which was firstly used to study the dendrite growth of metallic alloy.A series of growth behavior and morphology evolution of dendrite have been in situ observed,such as columnar-to-equiaxed transition,dendrite competition,dendrite fragmentation and floating,etc.,which can offer the direct proofs to verify or improve the solidification theories of metallic *** research opens a novel window for the study of alloy solidification and enables the unambiguous understanding of solidification processes in optically opaque,metallic alloys.

关键词： dendritic growth synchrotron radiation solidification diffraction-enhanced imaging metal and alloys

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Kinetics and reaction mechanism of phenol hydroxylation catalyzed by La-Cu_4FeAlCO_3

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Science china Chemistry 2005年第6期48卷 530-537页

作者： CHEN Chunxia1,2. XU Chenghua1, FENG Liangrong1, SUO Jishuan1 & QIU Fali1 1. Chengdu institute of Organic Chemistry, chinese academy of sciences, Chengdu 610041, {2. 2. Graduate School of the chinese academy of sciences, Beijing 100039, {2. 1. Chengdu institute of Organic Chemistry Chinese Academy of Sciences 610041 Chengdu China 2. Graduate School of the chinese academy of sciences 100039 Beijing China

The present work synthesizes La-Cu4FeAlCO3 catalyst under microwave irradiation and characterizes its structure using XRD and IR techniques. The results show that the obtained La-Cu4FeAlCO3 has a hydrotalcite structure. In the phenol hydroxylation with H2.2.catalyzed by La-Cu4FeAlCO3, the effects of reaction time and phenol/H2.2.molar ratio on the phenol hy-droxylation, and relationships between the initial hydroxylation rate with concentration of the catalyst, phenol, H2.2.and reaction temperature are also investigated in details. It is shown the phenol conversion can reach 50.09% (mol percent) in the phenol hydroxylation catalyzed by La-Cu4FeAlCO3, under the reaction conditions of the molar ratio of phenol/H2.2.1/2. the amount ratio of phenol/catalyst 2., reaction temperature 343 K, reaction time 12. min, 10 mL distilled water as solvent. Moreover, a kinetic equation of v = k[La ? Cu 4 FeAlCO 3 ][C 6 H 5 OH][H 2.O 2.. and the activation energy of Ea=58.37 kJ/mol are obtained according to the kinetic studies. Due to the fact that the HO-Cu+-OH species are detected in La-Cu4FeAlCO3/H2.2.system by XPS, the new mechanism about the generation of hydroxyl free radicals in the phenol hydroxylation is pro-posed, which is supposed that HO-Cu+-OH species are transition state in this reaction.

关键词： rare earth, hydrotalcite, microwave irradiation, phenol hydroxylation, kinetics, reaction mechanism.

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Simulation of the in-flight calibration of the collimator alignment and PSF for HXMT

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Science china(physics,Mechanics & Astronomy) 2010年第S1期53卷 47-50页

作者： XIONG ShaoLin,LI XinQiao,QU JinLu & LU FangJun Key Laboratory for Particle Astrophysics,institute of {2. energy physics,chinese academy of sciences(CAS),Beijing 100049,china 1. Key Laboratory for Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences (CAS) Beijing 100049 China

The Hard X-ray Modulation Telescope(HXMT) is an X-ray astronomical satellite in 1-2.0 keV,consisting of three collimated *** present the in-flight calibration approach of the collimator alignment and Point Spread Function(PSF) for HXMT,using both the direct fitting method and the imaging *** to observational simulations of the Crab Nebula,we find that these two methods produce almost the same calibration accuracy of the alignment,and with a one-day scanning observation,the alignment can be calibrated to better than 0.45' and 0.1' along the wide and narrow directions of the Field of View(FOV) for a detector module,which corresponds to a localization accuracy of better than 0.1' and meets the scientific requirement.

关键词： HXMT alignment PSF calibration

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Calibrating the HXMT collimators using diffuse illumination

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Science china(physics,Mechanics & Astronomy) 2010年第S1期53卷 36-39页

作者： HAN Dong1,JIN YongJie1,WU Mei2.& ZHANG Zhi1 1 Department of Engineering physics & Center for Astrophysics,Tsinghua University,Beijing 100084,{2. 2.Key Laboratory of Particle Astrophysics,institute of high energy physics,chinese academy of sciences,Beijing 100049,{2. 1. Department of Engineering physics & Center for Astrophysics Tsinghua University Beijing 100084 China 2. Key Laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China

We propose a new method to calibrate the HXMT collimators by measuring the optical point spread function(PSF) of the hard X-ray modulation telescope(HXMT).The light transmission of the collimator at different viewing angles with a camera and a diffuse backlight placed behind the collimator is *** method is much easier to accomplish than measuring the PSF with a parallel optical *** experimental results are very consistent with the *** PSF of the collimator of the high energy X-ray telescope on HXMT is found to be in good agreement with the design,with accuracy better than 1 arcmin.

关键词： HXMT collimator point spread function Monte Carlo simulation diffuse illumination

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The characteristic spectral lines of target atoms in the impact of^(40)Ar^(q+)ions on metal surfaces

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Science china(physics,Mechanics & Astronomy) 2004年第6期47卷 729-736页

作者： ZHANG Xiao’an1,2.ZHAO Yongtao1,2.LI Fuli1,YANG Zhihu2.XIAO Guoqing2.& ZHAN Wenlong2.1.Department of Applied physics,Xi’an Jiaotong University,Xi’an 710049,china 2.{2. of Modern physics,chinese academy of sciences,Lanzhou 730000,china Department of Applied physics Xi'an Jiaotong University Xi'an 710049 China institute of Modern physics Chinese Academy of Sciences Lanzhou 730000 China

We report the measured results of the 2.0 nm—1000 nm characteristic spectral lines of target atoms when highly charged ions40Ar q+(6≤q≤14) with the same kinetic energy and40Ar6+ with different kinetic energies are incident upon Al, Ti, Ni, Ta and Au surfaces, respectively. The results for12.Xe6+,12.Xe10+ and12.Xe15+ with the same kinetic energy (150 keV) incident upon a Ta surface are also reported. These results show that when the projectile and target are properly selected (40Ar12. impinges on Al,12.Xe6+ impinges on Ta), the spectral intensity of characteristic spectral lines of the target atom is effectively enhanced, and is not strongly dependent on the kinetic energy of the incident ions.

关键词： highly charged ion, hollow atom, characteristic spectrum, spectral intensity.

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Effect of the Small Reaustenized Grains on the Mechanical Properties of a HSLA Steel

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Journal of Iron and Steel Research International 2011年第S1期18卷 312-315页

作者： ZHAO Lian-yu 1,2.WEI Yan 1,SHAN Yi-yin 1,YANG Ke 1 (1.institute of Metal Research,chinese academy of sciences,Shenyang 110016,Liaoning,{2. 2.Graduate School of chinese academy of sciences,Beijing 100049,{2.) chinese Acad Sci Inst Met Res Shenyang 110016 Liaoning Peoples R China chinese Acad Sci Grad Sch Beijing 100049 Peoples R China

Grain refinement improves not only strength but also *** reaustenized grains were discovered to form along the grain boundaries and lath boundaries in an as rolled high-strength low-alloy (HSLA) steel when heated to double phase *** number and size of the small reaustenized grains were revealed to depend mainly on temperature in the range of 700 to 760℃.These small reaustenized grains were deduced to form by consuming *** mechanical property tests showed that they resulted in slight changes to tensile ***,the sample heated at 740℃ produced a peak Charpy V-notch (CVN) impact energy of 2.8J when tested at-30℃.Fractography showed that the facture surface of the 740℃ heated impact sample exhibited the smallest brittle zone away from the notch root and a large dimple zone lay ahead of the notch tip,which demonstrated the highest toughness.

关键词： high-strength low-alloy steel reaustenization grain refinement tensile property

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

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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 2.3} 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

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