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Brownian ratchets driven by flashing noise strength

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Chinese Science Bulletin 1999年第21期44卷 1956-1961页

作者： ZHAO Tongjun, ZHAN Yong, ZHUO Yizhong and WU XizhenDepartment of Applied Mathematics and physics , Hebei University of Technology , Tianjin 3.013., china china {3. of Atomic energy, beijing 102413. china {3. of Theoretical physics, Chinese Academy of Sciences , beijing 100080, china Corresponding author Dept. of Appl. Math. and physics Hebei University of Technology Tianjin 300130 China china institute of Atomic energy Beijing 102413 China institute of Theoretical physics Chinese Academy of Sciences Beijing 100080 China

The stochastic transport driven by flashing multi-noise sources in a ratchet is studied. The stationary current versus the noise strength and the colored noise correlated time T is obtained . At a fixed flip rate and strength of the colored noises, the novel phenomenon of the current reversal occurs as T reaches a certain value. More than one reversal point exists when

关键词： flashing force ratchet current reversal Langevian equation.

A study on the sharp knee and fine structures of cosmic ray spectra

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Science china(physics,Mechanics & Astronomy) 2010年第5期53卷 842-847页

作者： WANG Bo1,YUAN Qiang1,FAN Chao1,2,ZHANG JianLi1,HU HongBo1 & BI XiaoJun1 1 Key Laboratory of Particle Astrophysics,institute of high {3. physics,Chinese Academy of Sciences,beijing 100049,china 2 Department of physics,Shandong University,Jinan 250100,china Key Laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing China Department of physics Shandong University Jinan China

The paper investigates the overall and detailed features of cosmic ray(CR) spectra in the knee region using the scenario of nuclei-photon interactions around the acceleration *** supernova remnants can be the physical realities of such kind of CR acceleration *** results show that the model can well explain the following problems simultaneously with one set of source parameters:the knee of CR spectra and the sharpness of the knee,the detailed irregular structures of CR spectra,the so-called"component B"of Galactic CRs,and the electron/positron excesses reported by recent *** coherent explanation serves as evidence that at least a portion of CRs might be accelerated at the sources similar to young supernova remnants,and one set of source parameters indicates that this portion mainly comes from standard sources or from a single source.

关键词： cosmic ray knee fine structures e+e-excesses "component B" single source

Dark output characteristic of γ-ray irradiated CMOS digital image sensors

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Rare Metals 2002年第1期21卷 79-84页

作者： MENG Xiangti and KANG A iguo institute of Nuclear energy Technology, Tsinghua University, beijing 100084, {3. institute of Nuclear energy Technology Tsinghua University 北京 100084

The quality of dark output images from the CMOS (complementarymetal oxide semiconductor) black and white (B & W) digital imagesensors captured before and after γ-ray irradiation was studied. Thecharacteristic parameters of the dark output images captured atdifferent radiation dose, e.g. average brightness and itsnon-uniformity of dark out- put images, were analyzed by our testsoftware. The primary explanation for the change of the parameterswith the radi- ation dose was given.

关键词： CMOS digital image sensor gamma radiation dark output characteristic Si

A Study of Electromagnetic Transition of Δ(123.)Resonance

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Communications in Theoretical physics 2004年第7期 87-89页

作者： DONG Yu-Bing LIU Jian institute of high energy {3., the Chinese Academy of Sciences, beijing 10003., china

Point form relativistic dynamics of relativistic quantum mechanics is employed to estimate the photonand electroproduction amplitudes of Δ(123.) *** are compared with the non-relativistic work,and thedifferences betw... 详细信息

关键词： relativistic quantum mechanism point form dynamics

Lookback time as a test for f(R) gravity in the Palatini approach

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Research in Astronomy and Astrophysics 2011年第11期11卷 1257-1265页

作者： Zhong-Xu Zhai and Wen-Biao Liu Department of physics, institute of Theoretical physics, {3. Normal University, {3. 100875, china Department of physics Institute of Theoretical Physics Beijing Normal University Beijing 100875 China

We use the recently released data of lookback time (LT)-redshift relation, the cosmic microwave background shift parameter and the baryon acoustic oscillation measurements to constrain cosmological parameters of f (R) gravity in the Palatini formalism by considering the f (R) form of type (a) f (R) = R β/Rn and (b) f (R) = R + α ln R β. Under the assumption of a Friedmann-Robertson-Walker universe, we achieved the best fitting results of the free parameters (Ωm0, n) for (a) and (Ωm0, α) for (b). We find that current LT data can provide interesting and effective constraints on gravity models. Compared with other data, the LT constraints favor a smaller value of the non-relativistic matter energy density.

关键词： cosmology cosmic microwave background

Progress in multi-waveband observations of supernova remnants

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Progress in Natural Science:Materials International 2008年第9期18卷 1057-1062页

作者： Xuejuan Yang a,b, Fangjun Lua, Wenwu Tian c,d,* a Particle Astrophysics Center, institute of high {3. physics, Chinese Academy of Sciences, beijing 100049, china b Department of Astronomy, beijing Normal University, beijing 100875, china c National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, CAS, beijing 100012, china d Department of physics & Astronomy, University of Calgary, Alberta, Canada T2N 1N4 Particle Astrophysics Center Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China Department of Astronomy Beijing Normal University Beijing 100875 China National Astronomical Observatories Chinese Academy of Sciences 20A Datun Road Chaoyang District CAS Beijing 100012 China Department of physics & Astronomy University of Calgary Alberta Canada T2N 1N4

The development of observational techniques has enriched our knowledge of supernova remnants. In this paper, we review the main progresses in the last decade, including new discoveries of supernova remnants and the associated (rare type of) pulsars, nucleosynthesis, the interaction between supernova remnants and molecular clouds, dust in the supernova remnants, shock physics, and cosmic ray accelerations.

关键词： Supernova remnant Observations

Collision dynamics of He@C_(60)+He@C_(60) at low energies

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Science china(physics,Mechanics & Astronomy) 2008年第7期51卷 765-772页

作者： ZHAO Qiang1,2, ZHANG FengShou1,2,3.& ZHOU HongYu1,2 1 Key Laboratory of Beam Technology and Material Modification of Ministry of Education, institute of Low energy Nuclear physics, {3. Normal University, {3. 100875, china 2 {3. Radiation Center, {3. 100875, china 3.Center of Theoretical Nuclear physics, National Laboratory of Heavy Ion Accelerator of Lanzhou, Lanzhou 73.000, china Key Laboratory of Beam Technology and Material Modification of Ministry of Education Institute of Low Energy Nuclear Physics Beijing Normal University Beijing China beijing Radiation Center Beijing China Center of Theoretical Nuclear physics National Laboratory of Heavy Ion Accelerator of Lanzhou Lanzhou China

A semi-empirical molecular dynamics model is developed. The central collisions of C60+C60 and He@C60+He@C60 at different incident energies are investigated based on this model. It is found that the dimer structures have been produced at proper incident energies and these fullerene dimers could be formed by a self-assembly of C60 fullerene and He@C60. The He atom has a significant effect at higher incident energy and this embedded He atom can enhance the stability of the dimer structure.

关键词： C60 He@C60 collision molecular dynamics

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,{3. 2 Key Laboratory of Particle Astrophysics,institute of high energy physics,Chinese Academy of Sciences,beijing 100049,{3. Department of Engineering physics & Center for Astrophysics Tsinghua University Beijing China Key Laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing 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

FROM UNWEIGHTED TO WEIGHTED GENERALIZED FAREY ORGANIZED TREE AND THE PYRAMID NETWORKS

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Journal of Systems Science & Complexity 2010年第4期23卷 681-700页

作者： Yong LI·Jinqing FANG·Qiang LIU china institute of Atomic energy,{3. 102413.china. china institute of Atomic energy Beijing China

Generalized Farey tree network （GFTN） and generalized Farey organized pyramid network （CFOPN） model are proposed, and their topological characteristics are studied by both theoretical analysis and numerical simulations, which are in good accordance with each other. Then weighted GFTN is studied using cumulative distributions of its Farey number value, edge weight, and node strength. These results maybe helpful for future theoretical development of hybrid models.

关键词： Generalized Farey organized pyramid network topological properties weighted generalized Farey tree network.