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随机表面散射光场的格林函数法与基尔霍夫近似的比较

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物理学报 2004年第2期53卷 427-435页

作者：刘春香程传福任晓荣刘曼滕树云徐至展中国科学院物理研究所和凝聚态物理中心光物理实验室北京100080 中国科学院上海光学与精密机械研究所上海201800 山东师范大学物理系济南250014

从简谐光波满足的亥姆霍兹方程出发 ,将由格林定理得到的介质分界面上的积分方程转化为以表面上的光波及其导数为未知量的线性方程组 ,并对其进行数值求解 ,实现了光场的数值计算 .同时 ,由透射光场的格林函数积分得出了基尔霍夫近似下... 详细信息

从简谐光波满足的亥姆霍兹方程出发 ,将由格林定理得到的介质分界面上的积分方程转化为以表面上的光波及其导数为未知量的线性方程组 ,并对其进行数值求解 ,实现了光场的数值计算 .同时 ,由透射光场的格林函数积分得出了基尔霍夫近似下光场的表达式 .通过类比推导夫琅和费面上散斑场自相关函数的方法 ,提出了产生随机表面及其导数的傅里叶变换方法 .在此基础上 ,对采用基尔霍夫近似进行自仿射分形随机表面的散射光场数值计算的精确程度进行了研究 .发现在随机表面粗糙度比较小时 ,基尔霍夫近似的精度比较高 ;在粗糙度相同的情况下 ,表面的分形维数越小 ,基尔霍夫近似的精度越高 .

关键词：随机表面散射光场格林函数积分基尔霍夫近似简谐光波亥姆霍兹方程透射光场夫琅和费面自相关函数傅里叶变换

Relaxation of Chain Extension of Amorphous PET Fiber Above the Glass Transition Temperature

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chinese Chemical Letters 2000年第10期11卷 925-928页

作者： Xin LINGHU, Jun ZHAO, Rui SONG, Qing Rong FAN (Polymer Physics Laboratory, center of Molecular Science, institute of Chemistry,{2., beijing, 100080) Polymer Physics Laboratory Center of Molecular Science Institute of Chemistry Beijing 100080 China

The recovery of amorphous PET fiber in global chain orientation but nearly random segmental orientation (GOLR) state was studied by the hot shrinkage measurement above the glass transition temperature. The relaxation curves in the form of di-exponential decay were acquired and the change of two special times with the variation of treating temperature and residual recovery ratio ' was discussed.

关键词： GOLR state PET recovery of chain extension hot shrinkage measurement.

Characterization of different-Al-content AlGaN/GaN heterostructures on sapphire

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Science china(Physics,Mechanics & Astronomy) 2010年第1期53卷 49-53页

作者： DING GuoJian , GUO LiWei, XING ZhiGang, CHEN Yao, XU PeiQiang, JIA HaiQiang, ZHOU JunMing & CHEN Hong beijing National Laboratory of condensed {2. Physics, institute of Physics, chinese academy of sciences, beijing 100190, china 1. beijing National Laboratory of condensed {2. Physics Institute of Physics Chinese Academy of Sciences Beijing 100190 China

Al x Ga 1-x N/GaN high-electron-mobility transistor (HEMT) structures with Al composition ranging from x = 0.13 to 0.36 are grown on sapphire substrates by low-pressure metalorganic chemical vapor deposition (LP-MOCVD). The effects of Al content on crystal quality, surface morphology, optical and electrical characteristics of the AlGaN/GaN heterostructures have been analyzed. Although high Al-content (36%) heterostructure exhibits a distinguished photoluminescence peak related to recombination between the two-dimensional electron gas and photoexcited holes (2.EG-h), its crystal quality and rough surface morphology are poor. 2.EG mobility increases with the Al content up to 2.% and then it apparently decreases for high Al-content (36%) AlGaN/GaN heterostructure. The increase of sheet carrier density with the increase of Al content has been observed. A high mobility at room temperature of 2.05 cm 2./V s with a sheet carrier density of n s = 1.10 × 10 13 cm -2., for a 2.% Al-content AlGaN/GaN heterostructure has been obtained, which is approaching state-of-the-art for HEMT grown on SiC. Sheet resistance as low as 2.4 Ω/□ has also been achieved.

关键词： AlGaN Hall-effect luminescence

Improvement of refrigerant capacity of La_(0.67)Ca_(0.33)MnO_(3) single crystal with a few percent Fe doping

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Science china(Physics,Mechanics & Astronomy) 2009年第6期52卷 809-812页

作者： LI GuoKe, ZHANG XiangQun, KOU ZhiQi, LI QingAn, SUN Young & CHENG ZhaoHua State Key Laboratory of Magnetism, beijing National Laboratory of condensed {2. Physics and institute of Physics, chinese academy of sciences, beijing 100190, china State Key Laboratory of Magnetism Beijing National Laboratory of Condensed Matter Physics and Institute of Physics Chinese Academy of Sciences Beijing 100190 China

Large low-field-induced magnetic entropy changes, ΔSM, are observed in La0.67Ca0.33MnO3 and La0.67-Ca0.33Mn0.96Fe0.04O3 single crystals. The peaks of ΔSM broadened asymmetrically to high temperatures under higher magnetic fields for two materials should be attributed to the first-order magnetic phase transition at Tc. A small amount of iron doping results in an increase in the refrigerant capacity of the material though the magnetic entropy change decreases. The discovery of excellent magnetocaloric features of these single crystals in the low magnetic field can provide some ideas for exploring novel magnetic refrigerants operating under permanent magnet rather than superconducting one as magnetic field source.

关键词： single crystal magnetic entropy refrigerant capacity

Band gap anomaly and topological properties in lead chalcogenides

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chinese Physics B 2016年第3期25卷 27-34页

作者：聂思敏许霄琰徐刚方忠 beijing National Laboratory for condensed {2. Physics and Institute of Physics Chinese Academy of Sciences Beijing 1O0190 China Collaborative Innovation center of Quantum matter Beijing 100084 China

Band gap anomaly is a well-known issue in lead chalcogenides PbX （X = S, Se, Te, Po）. Combining ab initio calculations and tight-binding （TB） method, we have studied the band evolution in PbX, and found that the band gap anomaly in PbTe is mainly related to the high on-site energy of Te 5s orbital and the large s-p hopping originated from the irregular extended distribution of Te 5s electrons. Furthermore, our calculations show that PbPo is an indirect band gap （6.5 meV） semiconductor with band inversion at L point, which clearly indicates that PbPo is a topological crystalline insulator （TCI）. The calculated mirror Chern number and surface states double confirm this conclusion.

关键词： band gap anomaly lead chalcogenides indirect band gap semiconductor topological crystallineinsulator

Contradiction between strong lensing statistics and a feedback solution to the cusp/core problem

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Research in Astronomy and Astrophysics 2010年第12期10卷 1215-1222页

作者： Stacy McGaugh Department of Astronomy University of MarylandCollege Park

Standard cosmology has many successes on large scales, but faces some fundamental difficulties on small, galactic scales. One such difficulty is the cusp/core problem. High resolution observations of the rotation curves for dark matter domi- nated low surface brightness （LSB） galaxies imply that galactic dark matter halos have a density profile with a flat central core, whereas N-body structure formation simula- tions predict a divergent （cuspy） density profile at the {2.. It has been proposed that this problem can be resolved by stellar feedback driving turbulent gas motion that erases the initial cusp. However, strong gravitational lensing prefers a cuspy density profile for galactic halos. In this paper, we use the most recent high resolution observations of the rotation curves of LSB galaxies to fit the core size as a function of halo mass, and compare the resultant lensing probability to the observational results for the well defined combined sample of the Cosmic Lens All-Sky Survey （CLASS） and Jodrell Bank/Very Large Array Astrometric Survey （JVAS）. The lensing probabilities based on such density profiles are too low to match the observed lensing in CLASS/JVAS. High baryon densities in the galaxies that dominate the lensing statis- tics can reconcile this discrepancy, but only if they steepen the mass profile rather than making it more shallow. This places contradictory demands upon the effects of baryons on the central mass profiles of galaxies.

关键词： cosmology: theory -- dark matter -- galaxies: halos -- gravitationallensing: strong

Label-free high-throughput and real-time detections of protein interactions by oblique-incidence reflectivity difference method

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Science china(Physics,Mechanics & Astronomy) 2014年第4期57卷 615-618页

作者： HE LiPing LIU Shuang DAI Junbeijing National Laboratory for condensed {2. Physics institute of Physics chinese academy of sciences Lü HuiBin JIN KuiJuan YANG GuoZhen beijing National Laboratory for condensed {2. Physics Institute of Physics Chinese Academy of Sciences

Selected Mouse IgG of 1 mg/mL as target was fabricated on microarray for 500 sample ***-free and real-time reaction dynamic processes were detected between the microarrays with Goat Anti-mouse IgG of 0.02.mg/mL using the obliqueincidence reflectivity difference(OIRD)*** obtained the reaction results and the reaction dynamic curves of 500 protein *** addition,we also used label-free detection of protein microarrays of 10080 sample dots,including BSA and different concentrations of Mouse IgG and Rabbit IgG,by *** obtained reaction results between the protein microarray with 1 mg/mL Goat Anti-mouse IgG and 1 mg/mL Goat Anti-rabbit IgG are reported *** results show that OIRD can be not only label-free high-throughput detection method for biological microarrays but also label-free real-time detection in the interaction processes of biomolecules.

关键词： oblique-incidence reflectivity difference(OIRD) label-free real-time high-throughput

Impurity in Pairwise Entanglement of Heisenberg XX Open Chain

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Communications in Theoretical Physics 2007年第12期 1009-1016页

作者： XI Xiao-Qiang~(1,2.CHEN Wen-Xue~1 LIU Qi~3 and YUE Rui-Hong~3~1 Department of Applied Mathematics and Physics,Xi’an institute of Posts and Telecommunications,Xi’an 710061,china~2.Joint Laboratory of Advanced Technology in Measurements,{2. National Laboratory for condensed matter Physics,institute of Physics,the chinese academy of sciences,{2. 100080,china~3 institute of Modern Physics,North-West University,Xi’an 710069,china Department of Applied Mathematics and Physics Xi'an Institute of Posts and Telecommunications Xi'an 710061 China Joint Laboratory of Advanced Technology in Measurements Beijing National Laboratory for Condensed Matter Physics Institute of Physics the Chinese Academy of Sciences Beijing 100080 China Department of Applied Mathematics and Physics Xi'an Institute of Posts and Telecommunications Xi'an 710061 China institute of Modern Physics North-West University Xi'an 710069 China

We calculate the concurrence of all pairwise entanglement of Heisenberg XX open chain with single systemimpurity in three-qubit and four-qubit cases,and find that the impurity parameter J_i has great effect on *** the proper parameter J_i,we can obtain the maximal pairwise entanglement of the nearestqubits and make the non-nearest qubits entangle.

关键词： system impurity pairwise entanglement Heisenberg XX chain

电流注入对La_(0.8)Te_(0.2.MnO_3/YBa_2.u_3O_(7-δ)双层结构中YBa_2.u_3O_(7-δ)超导电性的影响

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中国稀土学报 2004年第5期22卷 719-721页

作者：朱亚彬周岳亮戴守愚北京交通大学理学院物理系北京100044 中国科学院物理研究所光物理实验室中国科学院凝聚态物理中心北京100080

用电泳法在厚度为5mm×10mm×0.5mm的YBa2.u3O7-δ上沉积厚约70μm的La0.8Te0.2.nO3形成La0.8Te0.2.nO3/YBa2.u3O7-δ(F/S)双层结构。通过扫描电子显微镜观察双层结构剖面的形貌,采用标准的四引线法测量YBa2.u3O7-δ层的电阻特性。在F/... 详细信息

用电泳法在厚度为5mm×10mm×0.5mm的YBa2.u3O7-δ上沉积厚约70μm的La0.8Te0.2.nO3形成La0.8Te0.2.nO3/YBa2.u3O7-δ(F/S)双层结构。通过扫描电子显微镜观察双层结构剖面的形貌,采用标准的四引线法测量YBa2.u3O7-δ层的电阻特性。在F/S双层结构中通入1mA的注入电流,无论电流从S层流入F层(+Iinj),或者电流从F层流入S层(-Iinj),正常电阻均比未加注入电流时的电阻低;超导转变温度均比未加注入电流的转变温度高。

关键词：金属材料庞磁电阻超导电性注入电流稀土