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Quantum properties of the binomial state field interacting with a two-level atom

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science China(Physics,Mechanics & Astronomy) 2010年第5期53卷 864-869页

作者： JIANG DaoLai,REN XueZao,CONG HongLu & LI Lei School of science,southwest university of science and technology,Mianyang 621010,China 1. School of science Southwest University of Science and Technology Mianyang 621010 China

By the method of coherent-state orthogonalization expansion,the atomic inversion and the anti-bunching effect in a two-level atomic system interacting with binomial state field are studied under the Jaynes-Cummings model without rotating wave *** influence of the parameter and the detuning on the anti-bunching effect are discussed,and the anti-bunching effect is also discussed under the conditions of strong *** studies show that the second order coherence degrees are quite different between the situations of with and without-rotating wave *** the latter when the detuning increases,the duration of the bunching effect increases at the beginning and then decreases,and finally the light field displays anti-bunching effect completely.

关键词： coherent state orthogonalization expansion binomial state field Jaynes-Cummings model without-rotating wave approximation atomic inversion

A new approximating method for Holstein model

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science China(Physics,Mechanics & Astronomy) 2010年第1期53卷 44-48页

作者： REN XueZao 1 , LIAO Xu 1 , LI Lei 1 & WANG KeLin 2 1 School of science, southwest university of science and technology, Mian Yang 621010, China 2 Department of Modern Physics, university of science and technology of China, Hefei 230026, China 1. School of science Southwest University of Science and Technology Mian Yang 621010 China2. Department of Modern Physics University of Science and Technology of China Hefei 230026 China

A new approach-the method of coherent state orthogonal expansion is developed for one-dimensional Holstein model. In zeroth order approximation, the formula of ground state energy is deduced analytically and the solutions in strong- and weak-coupling limits are obtained correctly. When the trial wave-function of ground state is expanded to the second order, the obtained ground state energy agrees quite well with that calculated by numerical method in all coupling regimes. The present approach can be easily generalized to the situations of higher dimensions and more electrons.

关键词： coherent-state orthogonal expansion polaron simulated annealing method

On a Class of Number Fields of Eisenstein Type

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Chinese Quarterly Journal of Mathematics 2004年第4期19卷 368-372页

作者： JIANG Jian-jun(College of science, southwest university of science and technology, Mianyang 621002, China) College of science Southwest University of Science and Technology Mianyang 621002 China

In this paper the author determine the factorization of p and the number of p-th subfields of the splitting field K of the irreducible binomial xp ?m(m is p-th powerfree and p | m) and obtain that all p-th subfields o... 详细信息

关键词： number field of Eisenstein type totally ramified prime ideal factorization element of Eisenstein type subfield of degree p

Combustion Synthesis and Luminescent Properties of CaO: Eu^(3+), M^+ (M=Li, Na, K) Phosphor

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Journal of Wuhan university of technology(Materials science) 2010年第2期25卷 179-183页

作者：康明 College of Material science and Engineering Southwest University of Science and Technology

Li ^＋ , Na^ ＋ , or K ^＋ co-doped CaO： Eu^3＋ phosphors were prepared by the combustion synthesis method and characterized by X-ray diffraction （XRD）, photoluminescence and photolumi-nescence excitation （PL-PLE） spectra. The experimental results show that, upon excitation with 250 nm xenon light, the emission spectrum of the CaO： Eu^3＋ consists of 4f-4f emission transitions from the 5D0 excited level to the 7FJ （J=1, 2, 3） levels with the mainly electric dipole transition 5D0→7F2 of Eu3＋, indicating that the Eu^3＋ occupies a low symmetry. The charge-transfer band （CTB） shows somewhat red shift with the decreasing ionic radii of co-doped alkali metal ions. The PL and PLE intensities are significantly enhanced, especially the strongest intensity of luminescent is CaO： Eu^3＋, Li ＋ phosphor, when alkali metal ions are incorporated. The strongest peak of emission is slightly shifted from 614 to 593 nm, indicating that the Eu^3＋ ion locates in a symmetric position （Oh） when alkali metal ions are incorporated.

关键词： luminescence CaO: Eu^3+ combustion method

Periodic Wave Solutions to Dispersive Long-Wave Equations in(2+1)-Dimensional Space

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Communications in Theoretical Physics 2005年第7期44卷 8-10页

作者： TIAN Ying-Hui CHEN Han-Lin LIU Xi-Qiang School of Mathematics and Physics, southwest university of science and technology, Mianyang 621010, China Department of Mathematics, Liaocheng university, Liaocheng 252059, China School of Mathematics and Physics Southwest University of Science and Technology Department of Mathematics Liaocheng University

Periodic wave solutions to the dispersive long-wave equations are obtained by using the F-expansionmethod, which can be thought of as a generalization of the Jacobi elliptic function method. In the limit case, solitar... 详细信息

关键词： dispersive long-wave equations F-expansion method periodic wave solutions Jacobi elliptic functions solitary wave solutions

Investigation on the surface active sites variation of mineral dusts

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Journal of Central South university 2001年第3期13卷 169-174页

作者： DONG Fa-qin, WAN Pu, FENG Qi-ming, SONG Gong-bao, PENG Tong-jiang (Institute of Mineral Materials and Applications, southwest university of science and technology, Mianyang 621002, China) 1. Institute of Mineral Materials and Applications Southwest University of Science and Technology 621002 Mianyang China

The paper analyzed the groups naked and the transformed of fibrous brucite, wollastonite, chrysotile asbestos, sepiolite, palygorskite, clinoptilolite, crocidolite and diatomaceous earth mineral dusts by using IR under acid and alkali etched, strong mechanical and polarized molecular interaction. The results show that the active site focuses on ends in stick dusts and on defects or hole edges in pipe dusts. The inside active sites of dusts play the main role in small molecular substance. The shape of dusts affects their distributions and densities of active sites. The strong mechanical and weak chemical force make the active site feature of minerals change, the powder process brings about more naked surface groups and more combined types. The dust activity relates to the type, contribution, and naked level of surface groups. The studied dust surface groups are mainly as follows: OH?, Mg(OH)?, Si-O-Si, Ca-O-Si, -Mg-OH2,-Al(Si)-OH, -Mg(Ca)-OH2, Ca-O,-Si???OH, Mg(Fe)-OH. Due to the difference of surface composition and structure, the minerals have a large disparity on activity and character of surface groups. The one side surface group of chrysotile layer is the same as fibrous brucite and stripped layer with more naked group. The fibrous sepiolite and palygorskite surface OH? similar to crocidolite is naked with their surface structural defects and cleavage. The more development of mineral defects, the higher of OH? (H2O+) content, the main H2O+ of clinoptilolite is partly transformed into H+, NH 4 + or OH?. The acid etched process may change OH? concentration, distribution and increase the defects and porosity of mineral fiber surface. The alkali etched has no effect on Si-O, Si-OH etc. and destroyed Al-O, Al-OH? acid site of sepiolite, palygorskite and clinoptilolite. Some surface groups of remnant differ from original dusts. The surface process of small polarized molecular or middle moleular’s branch may produce ionation and new coordinate bond, and change the acti

关键词： mineral dusts surface group active site

分子动力学方法研究金属Ti中He小团簇的迁移

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物理学报 2011年第12期60卷 428-432页

作者：陈敏西南科技大学国防科技学院绵阳621010

采用分子动力学方法模拟了不同温度下He原子及He团簇在金属Ti中的迁移特性,并计算了扩散前系数和激活能.研究发现这种扩散的各向异性非常显著,具体表现在He原子及He团簇在不同方向上扩散系数的前系数完全不同,但它们的激活能却相同.研... 详细信息

采用分子动力学方法模拟了不同温度下He原子及He团簇在金属Ti中的迁移特性,并计算了扩散前系数和激活能.研究发现这种扩散的各向异性非常显著,具体表现在He原子及He团簇在不同方向上扩散系数的前系数完全不同,但它们的激活能却相同.研究表明:在预测金属中He的扩散行为时,必须采用动态模拟方法才能得到准确的前系数,仅仅考虑势垒的静态模拟方法是不行的.另外,还发现一个不同于直觉的现象,即较低温度下He二聚物的扩散系数比单个He原子的扩散系数大;此外,在所模拟的温度范围内Arrhenius方程能够很好地描述它们的扩散.这说明动力学模拟对预测金属中He的扩散行为具有重要的意义.

关键词：分子动力学扩散系数各向异性氦

Photoluminescence and cathodoluminescence properties of a novel CaLaGa_3O_7:Dy^(3+) phosphor

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Chinese science Bulletin 2012年第7期57卷 827-831页

作者： ZHAO WenYu1,2, AN ShengLi1, FAN Bin1, LI SongBo1 & DAI YaTang3 1 School of Metallurgical and Ecological Engineering, university of science and technology Beijing, Beijing 100083, China 2 School of Chemistry and Chemical Engineering, Inner Mongolia university of science and technology, Baotou 014010, China 3 School of Materials science and Engineering, southwest university of science and technology, Mianyang 621000, China School of Metallurgical and Ecological Engineering University of Science and Technology Beijing School of Chemistry and Chemical Engineering Inner Mongolia University of Science and Technology

A single host white emitting phosphor, CaLaGa3O7:Dy3+, was synthesized by chemical co-precipitation. Field emission scanning electron microscopy, X-ray diffraction, laser particle size analysis, and photoluminescence and cathodoluminescence spectra were used to investigate the structural and optical properties of the phosphor. The phosphor particles were composed of microspheres with a slight tendency to agglomerate, and an average diameter was of about 1.0 μm. The Dy3+ ions acted as luminescent centers, and substituted La3+ ions in the single crystal lattice of CaLaGa3O7 where they were located in Cs sites. Under excitation with ultraviolet light and a low voltage electron beam, the CaLaGa3O7:Dy3+ phosphor exhibited the characteristic emission of Dy3+ (4F9/2-6H15/2 and 4F9/2-6H13/2 transitions) with intense yellow emission at about 573 nm. The chromaticity coordinates for the phosphor were in the white region. The relevant luminescence mechanisms of the phosphor are investigated. This phosphor may be applied in both field emission displays and white light-emitting diodes.

关键词：光致发光阴极射线荧光粉镝离子场发射扫描电子显微镜白色发光二极管特性 X射线衍射仪

A study of two-dimensional magnetic polaron

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science China(Physics,Mechanics & Astronomy) 2006年第4期49卷 421-429页

作者： LIU Tao1, ZHANG Huaihong1, FENG Mang1,2 & WANG Kelin1,3 1. School of science, southwest university of science and technology, Mianyang 621010, China 2. Wuhan Institute of Physics and Mathematics, Chinese Academy of sciences, Wuhan 430070, China 3. Department of Modern Physics, university of science and technology of China, Hefei 230026, China School of science Southwest University of Science technology Mianyang 621010 China Wuhan Institute of Physics Mathematics Chinese Academy of Sciences Wuhan 430070 China Department of Modern Physics University of Science technology of China Hefei 230026 China

By using the variational method and anneal simulation, we study in this paper the self-trapped magnetic polaron (STMP) in two-dimensional anti-ferromagnetic material and the bound magnetic polaron (BMP) in ferromagnetic material. Schwinger angular momentum theory is applied to changing the problem into a coupling problem of carriers and two types of Bosons. Our calculation shows that there are single-peak and multi-peak structures in the two-dimensional STMP. For the ferromagnetic material, the properties of the two-dimensional BMP are almost the same as that in one-dimensional case; but for the anti-ferromagnetic material, the two-dimensional STMP structure is much richer than the one-dimensional case.

关键词： self-trapped magnetic polaron, bound magnetic polaron, impurity potential, anti-ferromagnet.