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Spectral Parameters of Nd^(3+) in the Nd^(3+):GdMgB_5O_(10) Crystal

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Chinese Journal of Structural Chemistry 2005年第4期24卷 419-423页

作者： FANJun-Mei LINZhou-bin zhangli-Zhen HUZu-Shu WANGGuo-Fu StateKeyLaboratoryofStructuralChemistry FujianInstituteofResearchontheStructureofMatterTheChineseAcademyofSciencesFuzhouFujian350002China

The absorption and emission spectra of Nd3+:GdMgB5O10 crystal were inves- tigated. Based on Judd-Ofelt theory the three parameters of oscillator strength were obtained as follows: ?2 = 2.099×10-20 cm2, ?4 = 4.599×10-20 cm2 and ?6 = 5.139×10-20 cm2. The fluorescence branch rations were also obtained: β1 = 0.424, β2 = 0.474, β3 = 0.094 and β4 = 0.005. The radiative lifetime is 416 μs and quantum efficiency ηc 9.13%. The emission cross section σp (1.06 μm) is 4.38×10-19 cm2.

关键词： spectral parameters Nd3+:GdMgB5O10 crystal Judd-Ofelt theory

Synthesis and Structure of L-Aspartato- nickel(II) Complex with Benzimidazole

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Chinese Journal of Structural Chemistry 2004年第4期23卷 386-390页

作者： zhangli DAIZhi-Yuan DepartmentofFoodScience HangzhouInstituteofCommerceHangzhou310012China

The title complex Ni(C4H5NO4)(C7H6N2)31.75(H2O) (C25H26.5N7NiO5.75, Mr = 575.74) has been prepared and its crystal structure was determined by X-ray diffraction method. The crystal of this chiral complex belongs to monoclinic, space group P21 with a = 13.208(1), b = 10.741(1), c = 19.398(1) ? b = 104.39(1)o, V = 2665.8(4) 3, Z = 4, Dc = 1.435 g/cm3, m(MoKa) = 0.780 mm-1 and F(000) = 1198. The final R = 0.0504 and wR = 0.1267 for 9159 observed reflections (I > 2s(I)), and R = 0.065 and wR = 0.1299 for 11006 independent reflections. The complex assumes a distorted octa- hedral coordinate geometry formed by one aspartate dianion and three benzimidazole ligands. The aspartate chelates to the Ni atom as a tridentate ligand. The lattice water molecules are hydrogen- bonded to the Ni complex molecule.

关键词： Ni(II) complex aspartate crystal structure synthesis benzimidazole

Polar Oscillation of Interface and Surface Optical Phonons in Free-Standing Cylindrical Quantum-Well Wires

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Communications in Theoretical Physics 2004年第3X期42卷 459-466页

作者： zhangli DepartmentofMechanismandElectron PanyuPolytechnicCollegePanyu511483China

Under dielectric continuum approximation, interface optical (IO) and surface optical (SO) phonon modes aswell as the corresponding Frohlich electron-phonon interaction Hamiltonian in a free-standing cylindrical quantum-wellwire (Q WW) are derived and studied. Numerical calculations on GaAs/AlxGa1-xAs cylindrical QWW are *** reveal that there are two branches of IO phonon modes and one branch of SO phonon mode, and the dispersionfrequencies ofIO or SO phonon modes sensitively depend on the Al mole fraction x in Alx Ga1-x As material and the wave-vector in z direction, kz. With the increasing of κz and quantum number m, the frequency of each IO mode approaches oneof the two frequency values of the single GaAs/Alx Ga1-xAs heterostructure, and the electrostatic potential distributionof the phonon mode tends to be more and more localized at a certain interface or surface, meanwhile, the couplingbetween the electron-IO and -SO phonons becomes weaker.

关键词：光子模型圆柱形量子阱线量子点量子器件表面界面量子数

Vibration Spectrums of Polar Interface Optical Phonons in GaAs／AlAs Cylindrical Quantum Dots

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Communications in Theoretical Physics 2005年第2期43卷 333-336页

作者： zhangli SchoolofPhysics PekingUniversityBeijing100871China／／DepartmentofMechanismandElectronicsPanyuPolytechnicCollegePanyu511483China

The dispersions of the top interface optical phonons and the side interface optical phonons in cylindrical quantum dots are solved by using the dielectric continuum model. Our calculation mainly focuses on the frequency dependence of the IO phonon modes on the wave-vector and quantum number in the cylindrical quantum dot *** reveal that the frequency of top interface optical phonon sensitively depends on the discrete wave-vector in z direction and the azimuthal quantum number, while that of the side interface optical phonon mode depends on the radial and azimuthal quantum numbers. These features are obviously different from those in quantum well, quantum well wire,and spherical quantum dot systems. The limited frequencies of interface optical modes for the large wave-vector or quantum number approach two certain constant values, and the math and physical reasons for this feature have been explained reasonably.

关键词： phonon modes vibration spectrums cylindrical quantum dots

Studies on the Second-Order Nonlinear Optical Properties of Parabolic andSemi-parabolic Quantum Wells with Applied Electric Fields

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Communications in Theoretical Physics 2004年第5期41卷 761-766页

作者： zhangli XIEHong-Jing DepartmentofMechanicsandElectronics PanyuPolytechniqueCollegePanyu511483China DepartmentofPhysics GuihuagangCampusGuangzhouUniversityGuangzhou510405China

Within the framework of compact density matrix approach and iterative procedure, a detailed procedure for the calculation of the second-harmonic generation (SHG)susceptibility tensor is given in the electric-field-biased parabolic and semi-parabolic quantum wells (QWs). The simple analytical formula for the SHG susceptibility in the systems is also deduced. Numerical results on typical AlGaAs/GaAs materials show that, for the same effective width,the SHG susceptibility in semi-parabolic QW is larger than that in parabolic QW due to the self-asymmetry of the semiparabolic QW, and the applied electric field can make the SHG susceptibilities in both systems enhance ***, the SHG susceptibility is also related to the parabolic confinement frequency and the relaxation rate of the systems.

关键词： parabolic and semi-parabolic quantum wells electric field second-harmonic generation density matrix approach

Modeling of damage in materials during hot deformation based on the Zener-Hollomon parameter

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Rare Metals 2004年第1期23卷 88-92页

作者： LIUXuefeng WANGLingyun zhangli SchoolofMaterialsScienceandEngineering UniversityofScienceandTechnologyBeijing.Beijing100083China CollegeofMaterialsScienceandEngineering ChongqingUniversityChongqing400044.China Library ChongqingInstituteofTechnologyChongqing400050.China

By introducing the Zener-Hollomon parameter, which synthetically considersthe influence of deformation temperature and strain rate into damage mechanics, a damage evolutionmodel was developed to simulate the damage evolution of metallic materials during hot *** errors between the prediction damage values and the experimental ones are within 6%.

关键词： metallic materials damage evolution hot deformation zener-hollomonparameter

Development of Search System Used for Material Processing by Mobile Internet

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Journal of Iron and Steel Research International 2004年第3期11卷 33-36页

作者： WANGJun zhangli FANLei NortheasternUniversity Shenyang110004China DalianUniversityofTechnology Dalian116024China PoliceStartionofHuanggu Shenyang110036China)

A wireless search system was integrated on Windows 2000 *** on the communication principle between wireless data and Internet,the object expression of search file,the automatic query of document information,the segment browsing of result information,and the receiving and sending of user information were realized by using Active Server Page 3.0,VB Script,WML Script insert languages and object orient database *** requirement querying information of material processing through Internet by GPRS,WAP mobile handset and so on was accomplished.

关键词： material processing information search dynamic refreshment mobile Internet

Uniform Descriptions of Electron-IO Phonon Interaction in Structures of Multi-layer Coupling Low-dimensional Systems

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Communications in Theoretical Physics 2005年第1X期44卷 177-182页

作者： zhangli SHIJun-Jie DepartmentofMechanismandElectronics PanyuPolytechnicPanyu511483China//StateKeyLaboratoryforMesoscopicPhysicsandSchoolofPhysicsPekingUniversityBeijing100871China StateKeyLaboratoryforMesoscopicPhysicsandSchoolofPhysics PekingUniversityBeijing100871China

By using the transfer matrix method, within the framework of the dielectric continuum approximation,uniform forms for the interface optical (IO) phonon modes as well as the corresponding electron-IO phonon interaction Hamiltonians in n-layer coupling low-dimensional systems (including the coupling quantum well (CQ W), coupling quantum-well wire (CQWW), and coupling quantum dot (CQD)) have been presented. Numerical calculations on the three-layer asymmetrical AIGaAs/GaAs systems are performed, and the analogous characteristics for limited frequencies of IO phonon in the three types of systems (CQW, CQWW, and CQD) when the wave-vector and the quantum number approach zero or infinity are analyzed and specified.

关键词：三层不对称异质结构电子声子交互作用转移矩阵量子系统

Bound States and the Third Harmonic Generation in an Electric Field Biased Semi-parabolic Quantum Well

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Communications in Theoretical Physics 2003年第5X期40卷 614-618页

作者： zhangli XIEHong-Jing DepartmentofMechanicsandElectronicsCollege PanyuPolytechnicPanyu511483China DepartmentofPhysics GuihuagangCampusGuangzhouUniversityGuangzhou510405China

Within the framework of the compact density matrix approach, the third-harmonic generation (THG) in an electric-field-biased semi-parabolic quantum well (QW) has been deduced and investigated. Via variant of displacement harmonic oscillation, the exact electronic states in the semi-parabolic QW with an applied electric field have also been obtained and discussed. Numerical results on typical GaAs material reveal that, electric fields and confined potential frequency of semi-parabolic QW have obvious influences on the energy levels of electronic states and the THG in the semi-parabolic QW systems.

关键词：束缚态电场量子井密度矩阵趋近非线性光学低维量子系统