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Optimization of the imaginary time step evolution for the Dirac equation

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Science China(physics,Mechanics & Astronomy) 2011年第2期54卷 231-235页

作者： LI FangQiong1,ZHANG Ying2.LIANG HaoZhao2.3.& MENG Jie4,2.5 1Guizhou University for Nationalities,Guiyang 55002.,China 2.tate key Lab Nuclear {2. & Technology,School of {2.,Peking University,{3. 100871,China 3.nstitut de Physique Nucle’aire,IN2.3.CNRS and Universite’ Paris-Sud,F-91406 Orsay Cedex,France 4School of {2. and Nuclear energy Engineering,Beihang University,{3. 100191,China 5Department of {2.,University of Stellenbosch,Stellenbosch,South Africa 1. Guizhou University for Nationalities Guiyang 550025 China2. State Key Lab Nuclear Physics & Technology School of Physics Peking University Beijing 100871 China3. Institut de Physique Nucléaire IN2P3-CNRS and Université Paris-Sud F-91406 Orsay Cedex France4. School of Physics and Nuclear Energy Engineering Beihang University Beijing 100191 China5. Department of Physics University of Stellenbosch Stellenbosch South Africa

Taking the single neutron levels of 12. in the Fermi sea as examples,the optimization of the imaginary time step(ITS) evolution with the box size and mesh size for the Dirac equation is *** the weakly bound states,in order to reproduce the exact single-particle energies and wave functions,a relatively large box size is *** long as the exact results can be reproduced,the ITS evolution with a smaller box size converges faster,while for both the weakly and deeply bound states,the ITS evolutions are less sensitive to the mesh ***,one can find a parabola relationship between the mesh size and the corresponding critical time step,i.e.,the largest time step to guarantee the convergence,which suggests that the ITS evolution with a larger mesh size allows larger critical time step,and thus can converge faster to the exact *** conclusions are very helpful for optimizing the evolution procedure in the future self-consistent calculations.

关键词： Dirac equation Schrdinger-like equation imaginary time step method convergence

Convergence for Imaginary Time Step evolution in the Fermi and Dirac seas

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Science China(physics,Mechanics & Astronomy) 2010年第2期53卷 327-330页

作者： LI FangQiong1,ZHANG Ying2.& MENG Jie2.3.4 1Guizhou University for Nationalities,Guiyang 55002.,China 2.tate key Lab Nucl. Phys. & Tech.,School of {2.,Peking University,beijing 100871,China 3.chool of {2. and Nuclear energy Engineering,Beihang University,beijing 100191,China 4Department of {2.,University of Stellenbosch,Stellenbosch,South Africa 1. Guizhou University for Nationalities Guiyang 550025 China2. State Key Lab Nucl. Phys. & Tech. School of Physics Peking University Beijing 100871 China3. School of Physics and Nuclear Energy Engineering Beihang University Beijing 100191 China4. Department of Physics University of Stellenbosch Stellenbosch South Africa

The convergence for the Imaginary Time Step (ITS) evolution with time step is investigated by performing the ITS evolution for the Schrdinger-like equation and the charge-conjugate Schrdinger-like equation deduced from Dirac equation for the single proton levels of 12. in both the Fermi and Dirac seas. For the guaranteed convergence of the ITS evolution to the "exact" results,the time step should be smaller than a "critical" time step Δtc for a given single-particle level. The "critical" time step Δtc is more sensitive to the quantum numbers |κ| than to the energy of the single-particle level. For the single-particle levels with the same κ,their "critical" time steps are in the same order. For the single-particle levels with similar energy,a relatively small (large) "critical" time step for larger (smaller) |κ| is needed. These conclusions can be used in the future self-consistent calculation to optimize the evolution procedure.

关键词： Dirac equation Schrdinger-like equation Imaginary Time Step method convergence

分子筛改性Co／SiO2.化剂对Fischer-Tropsch合成汽油类烃的影响

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石油化工 2008年第5期37卷 445-449页

作者：李宇萍王铁军吴创之吕永兴李海滨中国科学院可再生能源与天然气水合物重点实验室

在中孔SiO2.添加USY，HZSM-5，β分子筛组成双功能载体，并采用初湿浸渍法在载体上浸渍钴盐，制备了一系列分子筛改性的Co／SiO2.化剂，考察了分子筛的类型、HZSM-5分子筛的骨架硅铝比、HZSM-5分子筛在载体中的含量对Fischer-Tropsch... 详细信息

在中孔SiO2.添加USY，HZSM-5，β分子筛组成双功能载体，并采用初湿浸渍法在载体上浸渍钴盐，制备了一系列分子筛改性的Co／SiO2.化剂，考察了分子筛的类型、HZSM-5分子筛的骨架硅铝比、HZSM-5分子筛在载体中的含量对Fischer-Tropsch合成汽油类烃（C5-12.的影响。实验结果表明，载体中SiO2.分子筛共同作用，提高了催化剂的活性，并使产物分布向汽油类烃偏移，其中，以HZSM-5分子筛改性的Co／SiO2.化剂的催化性能最好。HZSM-5分子筛改性催化剂对催化性能的影响受其骨架硅铝比的影响。当骨架硅铝比n（SiO2.：n（Al2.3.=3.、HZSM-5分子筛在载体中的质量分数为2.％时，CO转化率达到80％以上，汽油类烃的选择性高达55％，其中异构烷烃的选择性在10％以上。

关键词： Fischer-Tropsch合成钴/二氧化硅催化剂分子筛汽油类烃

Recombinant expression of rt-PA gene (encoding Reteplase) in gametophytes of the seaweed Laminaria japonica (Laminariales,Phaeophyta)

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Science China(Life sciences) 2008年第12期51卷 1116-1120页

作者： ZHANG YiChen1,2. JIANG Peng1, GAO JiangTao1,3. LIAO JianMin4, SUN ShiJing4, SHEN ZiLong4 & QIN Song1, 1 institute of Oceanology, {2., Qingdao 2.6071, China 2.College of Chemistry and Life Science, Tianjin Normal University, Tianjin 3.03.7, China 3.Graduate University of {2., {3., China 4 Biotechnology Center, China Pharmaceutical University, Nanjing 2.0009, China institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China College of Chemistry and Life Science Tianjin Normal University Tianjin 300387 China Graduate University of chinese academy of sciences Beijing 100049 China Biotechnology Center China Pharmaceutical University Nanjing 210009 China

The life cycle of seaweed Laminaria japonica involves a generation alternation between diploid sporophyte and haploid gametophte. The expression of foreign genes in sporophte has been proved. In this research, the recombinant expression in gametophyte was investigated by particle bombardment with the rt-PA gene encoding the recombinant human tissue-type plasminogen activator (Reteplase), which is a thrombolytic agent for acute myocardial infarction (AMI). Transgenic gametophytes were selected by their resistance to herbicide phosphiothricin (PPT), and proliferated in an established bubble column photo-bioreactor. According to the results from quantitative ELISA, Southern blotting, and fibrin agarose plate assay (FAPA) for bioactivity, it was showed that the rt-PA gene had been inte-grated into the genome of gametophytes of L. japonica, and the expression product showed the ex-pected bioactivity, implying the proper post-transcript modification in haploid gametophyte.

关键词： Laminaria japonica gametophyte genetic engineering Reteplase rt-PA bioreactor

Spectral Feature Analysis of Semiconductor Thin Disk Laser

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光机电信息 2007年第12期24卷 19-25页

作者： (HE Chun-feng1, QIN Li2. LI Jun1, CHENG Li-wen1, LIANG Xue-mei1, NING Yong-qiang2. WANG Li-jun2.1. key Laboratary of Excited State Processes, Changchun institute of Optics, Fine Mechanics and {2., {3.,Changchun 13.03., China Graduate School of the {3., beijing 100049, China 2. key Laboratary of Excited State Processes, Changchun institute of Optics, Fine Mechanics and {2., {3., Changchun 13.03.,China.) key Laboratary of Excited State Processes Changchun Institute of Optics Fine Mechanics and Physics Chinese Academy of SciencesChangchun 130033 China Graduate School of the chinese academy of sciences Beijing 100049 China key Laboratary of Excited State Processes Changchun Institute of OpticsFine Mechanics and Physics Chinese Academy of Sciences Changchun 130033China

The semiconductor thin disk laser is a new type of semiconductor laser. This work gives the basic operation function of the semiconductor disk laser, and analyses the heat effect by the experimentally measured photoluminescence spectrum of the laser chip at different pump power and different temperatures. We can see that: with increasing pump power, the thermal effect of the gain material becomes seriously and causes the saturation of carrier lifetime, so the electron-hole pair created in the absorbtion layer has no enough time to rate to one of the wells, and the non-radiative recombination happens in the barrier. When the thermal effect becomes stronger, the chip will be not lasing. This phenomenon is from the smaller energy offset between barrier and quantum well. We optimize the original structure design and experimental technology. A non-absorbing AlGaAs layer which is transparent to the pumping and laser wavelength is added to confine the carriers in the quantum wells. At the same time a DBR with double reflecting band is induced to improve the absorbing efficiency of the pumping light. The single QW is replaced by the three narrow QWs. This three QWs structure can add the quantum state of QW, increase the recombination probability of carriers in the QWs and reduce the heat effect. The chemical etching equipment is also improved to control the surface unevenness to be within 50 nm.

关键词： thin disk laser heat effect PL spectrum, active region heat removal gain barrier spectral shift

Penetrating view of nano-structures in Aleochara verna spermatheca and flagellum by hard X-ray microscopy

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chinese physics B 2013年第7期22卷 410-414页

作者：张凯李德娥洪友丽朱佩平袁清习黄万霞高昆周红章吴自玉 institute of High energy {2.h Chinese Academy of Sciences key laboratory of Zoological Systematics and Evolution Institute of ZoologyChinese Academy of Sciences National Synchrotron Radiation laboratory University of Science and Technology of China

A penetrating view of the three-dimensional nanostructure of female spermatheca and male flagellum in the species Aleochara verna is obtained with 100-nm resolution using a hard X-ray microscope, which provides a fast noninvasive imaging technology for insect morphology. Through introducing Zernike phase contrast and heavy metal staining, images taken at 8 keV displayed sufficient contrast for observing nanoscale fine structures, such as the spermatheca cochleate duct and the subapex of the flagellum, which have some implications for the study of the sperm transfer process and genital evolution in insects. This work shows that both the spatial resolution and the contrast characteristic of hard X-ray microscopy are quite promising for insect morphology studies and, particularly, provide an attractive alternative to the destructive techniques used for investigating internal soft tissues.

关键词： X-ray microscopy computed tomography synchrotron radiation source morphology

Size effects in lithium ion batteries

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chinese physics B 2016年第1期25卷 51-57页

作者：姚胡蓉殷雅侠郭玉国 CAS key laboratory of Molecular Nanostructure and Nanotechnology Institute of ChemistryChinese Academy of SciencesBeijing 100190China University of chinese academy of sciences Beijing 100049China Shandong Wina Green Power Co.Ltd. Shouguang 262705China

Size-related properties of novel lithium battery materials, arising from kinetics, thermodynamics, and newly discov- ered lithium storage mechanisms, are reviewed. Complementary experimental and computational investigations of the use of the size effects to modify electrodes and electrolytes for lithium ion batteries are enumerated and discussed together. Size differences in the materials in lithium ion batteries lead to a variety of exciting phenomena. Smaller-particle materials with highly connective interfaces and reduced diffusion paths exhibit higher rate performance than the corresponding bulk materials. The thermodynamics is also changed by the higher surface energy of smaller particles, affecting, for example, secondary surface reactions, lattice parameter, voltage, and the phase transformation mechanism. Newly discovered lithium storage mechanisms that result in superior storage capacity are also briefly highlighted.

关键词： lithium ion batteries size effects experiment calculation

用格子Boltzmann模型模拟垂直平板间的热对流

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物理学报 2004年第3期53卷 671-675页

作者：赵颖季仲贞冯涛中国科学院大气物理研究所大气科学和地球流体力学数值模拟国家重点实验室

引入一个新的能量分布函数 ,利用该能量分布函数与粒子速度分布函数耦合来求解一个热流场 .因而 ,这一能量分布函数与粒子速度分布函数和Boltzmann方程构成了一个新的格子Boltzmann模型 .这一模型满足质量、动量和能量守恒的准则 .用该... 详细信息

引入一个新的能量分布函数 ,利用该能量分布函数与粒子速度分布函数耦合来求解一个热流场 .因而 ,这一能量分布函数与粒子速度分布函数和Boltzmann方程构成了一个新的格子Boltzmann模型 .这一模型满足质量、动量和能量守恒的准则 .用该模型对垂直平板间的狭缝热对流进行了数值模拟 ,数值结果表明 ,在Prandtl数为 1,Grashof数在 1 3. 10 2.— 1× 10 6 之间时 ,流场将出现多个旋涡结构的流型 .

关键词：能量分布函数热对流 Boltzmann方程粒子速度分布函数能量守恒动量守恒质量守恒热力学

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基于裂解气质联用分析的生物质逐级热解研究

燃料化学学报 2010年第2期38卷 168-173页

作者：吴选民赵增立吴文强李海滨中国科学院广州能源研究所中国科学院可再生能源与天然气水合物重点实验室广东广州510640 中国科学院研究生院北京100049

为探究生物质快速热解反应历程,利用裂解气质联用仪对生物质进行逐级热解实验,考察在不同温度区间热解液体产物组分的分布规律。实验结果表明,生物质的化学组成和热解温度区间对热解液体产物都有重要影响。桉木在2.℃~400℃热解液体产... 详细信息

为探究生物质快速热解反应历程,利用裂解气质联用仪对生物质进行逐级热解实验,考察在不同温度区间热解液体产物组分的分布规律。实验结果表明,生物质的化学组成和热解温度区间对热解液体产物都有重要影响。桉木在2.℃~400℃热解液体产物较少,主要是吡喃和芳香类化合物,其中5,6-二氢-4-羟基-吡喃-2.酮相对峰面积随温度升高而降低;在450℃~500℃热解液体产物种类和产量均较多,主要以酮类和芳香类化合物为主。玉米芯热解规律和桉木的相似,但在2.℃~3.0℃主要以呋喃类化合物为主,主要热解液体产物是2.3.二氢-苯并呋喃和2.甲氧基-4-乙烯基苯酚,在400℃~450℃热解液体产物以酮类化合物为主。生物质主要化学组分在不同温度区间热解得到不同液体产物,对其进行选择性热解,能够有效实现生物质资源的综合利用。

关键词：生物质逐级热解裂解气质联用