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含有理想导体的准分形结构光子晶体的能带

物理学报 2004年第9期53卷 3205-3210页

作者：李岩郑瑞生冯玉春牛憨笨中国科学院西安光学精密机械研究所中国科学院研究生院北京100864 深圳大学光电子学研究所广东省光电子器件与系统重点实验室深圳518060

用时域有限差分方法计算了一组具有相似几何结构且包含理想金属材料的准分形光子晶体的能带 .数值计算结果表明 ,这种准分形结构光子晶体具有绝对带隙 ,且带隙的宽度会随着分形级数的增大而增大 .同时 ,随着级数的增大 ,其能带在整体地... 详细信息

用时域有限差分方法计算了一组具有相似几何结构且包含理想金属材料的准分形光子晶体的能带 .数值计算结果表明 ,这种准分形结构光子晶体具有绝对带隙 ,且带隙的宽度会随着分形级数的增大而增大 .同时 ,随着级数的增大 ,其能带在整体地趋向于高频端的同时。

关键词：光子晶体带隙时域有限差法分形级数能带结构

分子筛改性Co／SiO2催化剂对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中添加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催化剂，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中添加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催化剂，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和分子筛共同作用，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催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（Al2O3.=3.、HZSM-5分子筛在载体中的质量分数为20％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

Fabrication of GaN-based LEDs with 22° undercut sidewalls by inductively coupled plasma reactive ion etching

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chinese Physics B 2013年第10期22卷 445-448页

作者：王波宿世臣何苗陈弘吴汶波张伟伟王巧陈虞龙高优张力朱克宝雷严 laboratory of Nanophotonic Functional Materials and Devices Institute of Optoelectronic Materials and TechnologySouth China Normal University key laboratory for Renewable energy Chinese Academy of SciencesBeijing Key Laboratory for New Energy Materials and DevicesBeijing National Laboratory for Condense Matter PhysicsInstitute of PhysicsChinese Academy of Sciences

We use a simple and controllable method to fabricate GaN-based light-emitting diodes （LEDs） with 22° undercut sidewalls by the successful implementation of the inductively coupled plasma reactive ion etching （ICP-RIE）. Our exper- iment results show that the output powers of the LEDs with 22° undercut sidewalls are 3..8 rnW under a 20-mA current injection, 6.75% higher than 3..6 mW, the output powers of the conventional LEDs under the same current injection.

关键词： GaN light-emitting diode (LED) undercut

Ultrafast photo-induced turning of magnetization and its relaxation dynamics in GaMnAs

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Science china(Physics,Mechanics & Astronomy) 2010年第5期53卷 779-782页

作者： LUO Jing,ZHENG HouZhi,SHEN Chao,ZHANG Hao,ZHU Ke,ZHU Hui,LIU Jian,LI GuiRong,JI Yang & ZHAO JianHua State key laboratory for Superlattices and Microstructures,Institute of Semiconductors,chinese {3. of Sciences,beijing 100083.china 1. State key laboratory for Superlattices and Microstructures Institute of Semiconductors Chinese Academy of Sciences Beijing 100083 China

We report that,by linearly polarized pumping of different wavelengths,Kerr transients appear at zero magnetic field only in the case when GaMnAs samples are initialized at 3.K by first applying a 0.8 Tesla field and then returning to zero *** find that,instead of magnetization precession,the near-band gap excitation induces a coherent out-of-plane turning of magnetization,which shows very long relaxation dynamics with no *** photon energy increases,the peak value of the Kerr transient increases,but it decays rapidly to the original slow transient seen under the near-band-gap excitation.

关键词： dilute magnetic semiconductor magneto-crystalline anisotropy time-resolved Kerr rotation coherent precession

Azimuthal anchoring of a nematic liquid crystal on a grooved interface with anisotropic polar anchoring

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chinese Physics B 2012年第6期21卷 378-384页

作者：周璇张志东叶文江宣丽 State key laboratory of Applied Optics Changchun Institute of OpticsFine Mechanics and PhysicsChinese Academy of Sciences Graduate School of the chinese academy of Sciences Department of Physics Hebei University of Technology

Zhang Y J et al.[Zhang Y J,Zhang Z D,Zhu L Z and Xuan L 2011 Liquid Cryst.3. 3.5] investigated the effects of finite polar anchoring on the azimuthal anchoring energy at a grooved interface,in which polar anchoring was isotropic in the local tangent plane of the *** this paper,we investigate the effects of both isotropic and anisotropic polar anchoring on the surface anchoring energy in the frame of Fukuda et al.’s *** results show that anisotropic polar anchoring strengthens the azimuthal anchoring of grooved *** the one-elastic-constant approximation（K11 = K22 = K3. = K）,the surface-groove-induced azimuthal anchoring energy is entirely consistent with the result of Faetti,and it reduces to the original result of Berreman with an increase in polar ***,the contribution of the surface-like elastic term to the Rapini-Papoular anchoring energy is zero.

关键词： azimuthal anchoring energy surface grooves anchoring isotropy anchoring anisotropy

On the sand surface stability in the southern part of Gurbantünggüt Desert

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中国科学：地球科学英文版 2005年第6期48卷 778-785页

作者： WANG Xueqin1,2, WANG Tao1, JIANG Jin2 & ZHAO Congju2 1. laboratory of Blown Sand Physics and Desert Environment, Cold and Arid Regions of Environmental and Engineering Research In-stitute, chinese academy of Sciences, Lanzhou 73.000, {3. 2. Xinjiang Institute of Ecology and Geography, chinese academy of Sciences, Urmqi 83.011, {3. Correspondence should be addressed to Wang Xueqin 1. laboratory of Blown Sand Physics and Desert Environment Cold and Arid Regions of Environmental and Engineering Research In-stitute Chinese Academy of Sciences 730000 Lanzhou China 2. Xinjiang Institute of Ecology and Geography Chinese Academy of Sciences 830011 Urümqi China

Longitudinal dunes are the most widespread dune types in the world sand seas but comprehensive study on the sand surface stability is scarce. The southern part of Gurbantnggt Desert is mainly covered by longitudinal dune in which fixed and semi-fixed dunes occupy over 80% of the total area. Systematic analysis on the climatic conditions, the soil moisture and vegetation distributions, and the sand surface activities showed that the fixed and semi-fixed dunes are in a comprehensive low-energy wind environment. Snow cover and frozen soil provide a good protection to the ground surface in winter. The temporal distribution of precipitation and corresponding variation of temperature create a favorable condition for the desert plants growth, especially for the ephemeral plants. The occurrence of effective winds for sand moving in April to June coincides with the stage of relatively wet sand surface and good vegetation cover, which effectively keep the sand surface stable at the interdune and the plinth of the dunes. Activity sand surface appears only at the crest and the upper part of the sand dunes.

关键词： Gurbantünggüt Desert, longitudinal dune, sand surface stability.

SYNTHESIS AND CHARACTERIZATION OF PHTHALAZINONE POLY(ARYL ETHER SULFONE KETONE)WITH CARBONYL GROUP

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chinese Journal of Polymer Science 2002年第3期20卷 225-229页

作者： Ying-nan Xuan Yan Gao Yong Huang Xi-gao Jian laboratory of Cellulose and Lignocellulosics Chemistry Guangzhou Institute of Chemistry chinese academy of Sciences, Guangzhou 510650 {3. Institute of Chemistry chinese academy of Sciences, beijing 100080 {3. Department of Polymer Science, College of Chemical Engineering Dalian University of Technology, Dalian 116012, {3. chinese Acad Sci Guangzhou Inst Chem Lab Cellulose & Lignocellulos Chem Guangzhou 510650 Peoples R China chinese Acad Sci Inst Chem Beijing 100080 Peoples R China Dalian Univ Technol Coll Chem Engn Dept Polymer Sci Dalian 116012 Peoples R China

A kind of novel heat-resistant, high performance engineering thermoplastic phthalazinone poly(aryl ether sulfone ketone) (PPESK) containing a carboxyl group in its side chain was prepared by the nucleophilic displacement reaction of 4-(4-hydroxylphenyl)- 1 (2H)-phthalazinone with di(4-chlorophenyl) sulfone, 4,4'-difluoro-benzophenone and phenolphthalin in sulfolane in the presence of K2CO3.to produce high molecular weight polymers which can be dissolved in some polar solvents such as chloroform and nitrobenzene at room temperature and can be easily cast into flexible, yellowish and transparent films. PPESK is an amorphous polymer having a decomposition temperature above 400degreesC, which indicates that it has high thermal stability. At the same time, the thermal properties of PPESKs with dicyandiamide (DICY) as curing agent indicated that the heat-resistance properties of the PPESKs are improved after curing. The apparent activation energy (A-E) of the cross-linking reaction and the reaction order (n) of PPESK/DICY were found to be 52.2 kJ/mol and ca. 1.0, respectively. Therefore, the cross-linking reaction is approximately a first order reaction.

关键词： poly(aryl ether sulfone ketone) synthesis active pendant group

Al-doping-induced magnetocapacitance in the multiferroic CuCrS_2

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chinese Physics B 2013年第2期22卷 477-480页

作者：刘荣灯刘蕴韬陈东风何伦华闫丽琴王志翠孙阳王芳卫 china Institute of Atomic energy State key laboratory of Magnetism Beijing National Laboratory for Condensed Matter PhysicsInstitute of Physics Chinese Academy of Sciences

In this paper,magnetic and dielectric properties of the quasi-two-dimensional triangular-lattice system CuCrS2 and its B-site-diluted analogs CuAl1-xCrxS2（x = 0.01 and x = 0.02） are *** phase transition is observed at about 3..5 K by magnetization measurement without shift induced by a small amount of doping *** effect is found near TN in each of the three *** dielectric constant decreases and the magnetocapacitance increases with the increase of substitution of nonmagnetic Al3. ions for the magnetic Cr^3. *** negative magnetocapacitive effect reaches ～ 13. for CuAl0.02Cr0.98S2.

关键词： magnetocapacitance dielectric property magnetoelectric coupling antiferromagnetics

Predicting the shock arrival time using 1D-HD solar wind model

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Predicting the shock arrival time using 1D-HD solar wind mod...