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The optical near-field speckles and their first order statistics on the basis of the integral equations of electromagnetic field

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Science china(Physics,Mechanics & Astronomy) 2004年第3期47卷 365-380页

作者： CHENG Chuanfu1, 2. SONG Hongsheng2. LIU Chunxiang2. REN Xiaorong2. ZHANG Ningyu3, TENG Shuyun1 & XU Zhizhan1 1. Shanghai institute of Optics and Fine Mechanics, Chinese Academy of Sciences, P. O. Box 800-2.1, Shanghai 2.1800, china 2. {2. of Physics, shandong Normal University, jinan 2.0014, china 3. shandong institute of Architecture and Engineering, jinan 2.0014, china 1. Shanghai institute of Optics and Fine Mechanics Chinese Academy of Sciences P. O. Box 800-211 201800 Shanghai China 2. department of Physics Shandong Normal University 250014 Jinan China 3. shandong institute of Architecture and Engineering 250014 Jinan China

From Helmholtz equation of the harmonic electromagnetic waves, the integral equations of the light field at the medium boundaries are obtained by use of the Green's theorem and are discretized into linear equation set with the values of the light field and its derivative as the unknowns. On solving the linear equation set, we realize the rigorous computations of the light fields at the boundaries. Then the intensities of the light waves scattered by the random self-affine fractal surfaces in the optical near-field are calculated, and the propagation characteristics, the evolutions of the contrast and the intensity probability density function of the near-field speckles are studied in detail. The near-field speckles are much different from the conventional speckles in the diffraction regions and in the imaging systems. There are obvious local fluctuations in the intensity distributions of the near-field speckles and such fluctuations disappear after propagating a distance of one wavelength from the medium surfaces. For the random surfaces with smaller lateral correlation lengths, the speckle contrasts approach the saturation values and the speckle fields approach Gaussian distribution within the near-field, while for the random surfaces with larger lateral correlation lengths, such evolutions become comparatively slow.

关键词： speckle, near-field optics, first order statistics, Green's function.

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Recurrence spectra of He atoms in strong external fields

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Science china(Physics,Mechanics & Astronomy) 2004年第4期47卷 477-484页

作者： LIN Shenglu1, LI Hongyun1, WANG Dehua2. ZHAO Wenli1 & GAO Feng1 1. department of Physics, shandong Normal University,{2., china 2. department of Mathematics and Physics, shandong institute of Architecture and Engineering,{2., china 1. department of Physics Shandong Normal University 250014 Jinan China 2. department of Mathematics and Physics Shandong Institute of Architecture and Engineering 250014 Jinan China

By employing a model potential including the electron exchange energy, we extend the semiclassical closed orbit theory to study the multielectron atoms. Using special region-splitting consistent and iterative method, we figure out the closed orbits in the corresponding classical system and calculate the recurrence spectra of triplet helium atoms in parallel electric and magnetic fields at scaled energy ε=?0.03,n≈40,n=0. The core-scattering effects have been taken into account, which lead to more peaks in the spectra. It has also been confirmed by means of the direct comparison between the spectral portrait in such a plot and those of hydrogen case. In order to compare the theoretic results with experiment, we investigate the closed orbits and recurrence spectra of helium atoms for the similar exchange potential but applied only by single electric field at scaled energy ε=?2.7 case. The spectra are in good agreement with the experimental observation. We conclude that our model is correct and it is necessary to consider the exchange effect for determining the photoabsorption spectra of multielectron atoms in strong external fields.

关键词： exchange potential, recurrence spectra, semiclassical closed orbit theory, core-scattering.

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Sol-gel preparation and spectroscopic study of the pyrophanite MnTiO_3 nanoparticles

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Science china chemistry 2005年第3期48卷 210-215页

作者： ZHOU Guowei1, KANG Youngsoo2. LI Tianduo1 & XU Guiying3 1. School of Light Chemicals and Environmental Engineering, shandong institute of Light Industry, {2. 2.0100, china 2. department of chemistry, Pukyong National University, Daeyeon-3-dong, Nam-gu, Pusan 608-737, Korea 3. Key Laboratory for Colloid and Interface of Ministry of education of china, shandong University, {2. 2.0100, china 1. School of Light Chemicals and Environmental Engineering Shandong Institute of Light Industry 250100 Jinan China 2. department of chemistry Pukyong National University Daeyeon-3-dong Nam-gu 608-737 Pusan Korea 3. Key Laboratory for Colloid and Interface of Ministry of education of china Shandong University 250100 Jinan China

The nanosized xerogel of titanium dioxide (TiO2. and manganese oxides (MnO2. Mn2.3, Mn3O4) was prepared by the sol-gel method using manganese chloride (MnCl2.4H2.) and titanium isopropoxide (Ti(O-iPr)4) as precursors in cetyltrimethylammonium bromide (CTAB)/ ethanol/H2./HCl micelle solutions, following the calcinations of the produced powders at differ-ence temperatures. The nanostructure and phase composition of these nanoparticles were characterized with X-ray powder diffraction (XRD), transmission electron microscopy (TEM), en-ergy dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS). The spectroscopic characterizations of these nanoparticles were also done with UV-Vis spectroscopy and laser Raman spectroscopy (LRS). XRD patterns show that the pyrophanite MnTiO3 phase was formed at the calcinations temperature of 900℃. The TEM images show that the nanoparti-cles are almost spherical or slight ellipose and the sizes are 50 nm on average. The UV-Vis spectra show that the nanosized MnTiO3 have significant absorption bands in the visible region. There are new absorption peaks of MnTiO3 nanoparticles in LRS compared with the pure TiO2.powder.

关键词： pyrophanite MnTiO3, nanoparticles, spectroscopy, CTAB micelle, sol-gel.

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Calculation of the molecular exchanging energy of binary surfactants system on the surface monolayer of aqueous solution

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Science china chemistry 2007年第4期50卷 468-475页

作者： WANG ZhengWu1 & YI XiZhang2.1 department of Food Sciences & Technology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 2.02.0, china 2.{2. of Theoretical chemistry, shandong University, jinan 2.0100, china 1. department of Food Sciences & Technology School of Agriculture and Biology Shanghai Jiao Tong University Shanghai 200240 China 2. institute of Theoretical chemistry Shandong University Jinan 250100 China

By using the binary anionic/cationic surfactants system CH3(CH2.nOSO_3/CH3(CH2.nN+(CH3)3 as an ex-ample, the molecular exchanging energy (ε) of adsorption on the surface monolayer of aqueous solu-tion has been studied. ε can be obtained with two methods. One is from the relationship between ε and the molecule interaction parameter (β). This relationship is founded by considering that the adsorption of mixed surfactants on the surface monolayer of solution satisfies the dimensional crystal model condition under which β can be obtained by testing the surface tension of solution. The other is directly from the molecular structure of surfactants with the Lennard-Jones formula. The results for the studied system show that these two methods coincide well.

关键词： surfactant molecule exchanging energy dimensional crystal model

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Patterned self-assembled film guided electrodeposition

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Science china chemistry 2004年第2期47卷 120-125页

作者： ZHOU Feng1, LI Bin1,2. XU Tao1, CHEN Miao1, HAO Jingcheng1 & LIU Weimin1 1. State Key Laboratory of Solid Lubrication, Lanzhou institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, china {2., shandong institute of education, jinan 2.0014, china 1. State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical Physics Chinese Academy of Sciences 730000 Lanzhou China 2. department of chemistry Shandong Institute of Education 250014 Jinan China

The paper describes the fabrication of polypyrrole (PPy) microstructures through patterned self-assembled film guided electrodeposition. Thus the patterned self-assembled monolayer is prepared by microcontact printing (μCP) and used as the template in the electrodeposition of PPy. It has been found that the self-assembled monolayer plays completely different roles on different substrates in directing the deposition of the PPy. Namely, the electrodeposition mainly occurs on the exposed area of the gold substrates patterned with dodecanethiol (DDT) and octadecanelthiol (ODT) and on the indium tin oxide (ITO) substrate patterned with octadecyltrichlorosilane (OTS), while PPy nucleates on the OTS covered area and no deposition is found on the exposed area of a semiconductor substrate (silicon). This is attributed to the co-operative effect between the substrate conductivity and the compatibility of the PPy oligomerwith the covered or exposed area of the substrate surface.

关键词： pattern, conducting polymer, microcontact printing, electrodeposition.

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Fabrication of hexagonal gallium nitride films on silicon (111) substrates

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Rare Metals 2003年第3期22卷 221-225页

作者： YANGLi XUEChengshan WANGCuimei LIHuaixiang RENYuwen chemistryFunctionMaterialsLab InstituteofSemiconductorsShandongNormalUniversityJinan250014China PhysicsDe0artment ShandongNormalUniversityJinan250014China InspectioninstituteforElectronicProductsofshandong Jinan250000China

Hexagonal gallium nitride films were successfully fabricated throughammoniating Ga_2._3 films deposited on silicon (111) substrates by electrophoresis. The structure,composition, and surface morphology of the formed films were characterized by X-ray diffraction(XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmissionelectron microscopy (TEM). The measurement results reveal that the polycrystalline GaN films withhexagonal wurtzite structure were successfully grown on the silicon (111) substrates. Preliminaryresults suggest that varying the ammoniating temperature has obvious effect on the quality of theGaN films formed with this method.

关键词： semiconductor materials GaN films electrophoresis Ga_2._3

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A Hybrid of Theorems of Goldbach and Piatetski-Shapiro

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Chinese Annals of Mathematics,Series B 2006年第3期27卷 341-352页

作者： Xianmeng MENG Mingqiang WANG School of Computer Science and Technology, shandong University, jinan 2.0100,{2. department of Statistics and Mathematics, shandong Finance institute, jinan 2.0014,{2.. School of Computer Science and Technology, shandong University, jinan 2.0100,{2. department of Mathematics, Qufu Normal University, Qufu 2.3165, shandong,{2.. School of Computer Science and Technology Shandong University Jinan 250100 China department of Statistics and Mathematics Shandong Finance Institute Jinan 250014 China department of Mathematics Qufu Normal University Qufu 273165 Shandong China

It is proved that for almost all sufficiently large even integers n, the prime variable equation n = p1 ＋ p2. p1 ∈ Pγ is solvable, with 13/15 〈γ≤ 1, where Pγ = {p ｜p = [m^1/γ], for integer m and prime p} is t... 详细信息

关键词： Circle method Sieve method Goldbach problem

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Density functional study on enantioselective reduction of keto oxime ether with borane catalyzed by oxazaborolidine

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Science china chemistry 2006年第4期49卷 296-307页

作者： LI Ming1, ZHENG Wenxu2.& TIAN Anmin2.1. department of chemistry, Southwest-{2. Normal University, Chongqing 400715, china 2. department of chemistry, Sichuan University, Chengdu 610064, china 1. department of chemistry Southwest-China Normal University Chongqing 400715 China 2. department of chemistry Sichuan University Chengdu 610064 China

The enantioselective reduction of keto oxime ether with borane catalyzed by oxazaborolidine is discussed by the density functional theory (DFT) method. The main intermediates and transition states for this reaction are optimized completely at the B3LYP/6-31g(d) level, and the transition states are verified by vibrational modes. As shown, the chirality-controlled steps for this re- action are the hydride transfer from borane to carbonyl carbon and oxime carbon of keto oxime ether, and the chirality for the reduced products is determined in these two reaction steps. In all examined reaction paths, the first hydride is transferred via a six-membered ring and the second hydride via a five-membered ring or a four-membered ring.

关键词： keto oxime ether, oxazaborolidine, enantioselective reduction, DFT.

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Demagnetization Process and Coercivity for Anisotropic HDDR NdFeB Bonded Magnets

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Journal of Materials Science & Technology 2000年第4期16卷 445-446页

作者： Ruwei GAO and Jiancheng ZHANG (Physics department, shandong University, {2. 2.0100, china) Xianhong DENG and Yongjun ZHANG (shandong Metallurgical Research institute, jinan 2.0014, china) Physics department Shandong University Jinan 250100 China shandong Metallurgical Research institute Jinan 250014 China

The demagnetization process and the coercivity mechanism for amsotropic HDDR Nd(Fe,Co)B bonded magnets were studied by comparing the dependence of coercivity on the alignment field applied while the powders were pressed. The results showed that both the remanence and the coercivity of magnet increased with increasing alignment field. The demagnetization process of the magnet can be classified as the nucleation process inside the grains and the domain-wall motion between the grains. The combined effect of two processes determines the coercivity of HDDR NdFeB bonded magnets.

关键词： NdFeB HDDR Demagnetization Process and Coercivity for Anisotropic HDDR NdFeB Bonded Magnets

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The dynamical properties of Rydberg hydrogen atom near a metal surface

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Science china(Physics,Mechanics & Astronomy) 2005年第6期48卷 667-675页

作者： GE Meihua1, ZHANG Yanhui1, WANG Dehua2. DU Mengli3 & LIN Shenglu1 1. College of Physics and Electronics, shandong Normal University, jinan 2.0014,{2. 2. department of Mathematics and Physics, shandong institute of Architecture and Engineering, jinan 2.0014,{2. 3. institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100080,{2. 1. College of Physics and Electronics Shandong Normal University 250014 Jinan China 2. department of Mathematics and Physics Shandong Institute of Architecture and Engineering 250014 Jinan China 3. institute of Theoretical Physics Chinese Academy of Sciences 100080 Beijing China

The dynamical properties of Rydberg hydrogen atom near a metal surface are presented by using the methods of phase space analysis and closed orbit theory. Transforming the coordinates of the Hamiltonian, we find that the phase space of the system is divided into vibrational and rotational region. Both the Poincaré surface of section and the closed orbit theory verify the same conclusion clearly. In this paper we choose the atomic principal quantum number as n = 2.. The dynamical character of the exited hydrogen atom depends sensitively on the atom-surface distance d. When d is sufficiently large, the atom-surface potential can be expressed by the traditional van der Waals force and the system is integrable. When d becomes smaller, there exists a critical value dc. For d > dc, the system is near-integrable and the motion is regular. While chaotic motion appears for d < dc, and the system tends to be non-integrable. The trajectories become unstable and the electron might be captured onto the metal surface.

关键词： Rydberg hydrogen atom, van der Waals interaction, Poincaré surface of section, closed orbit theory, chaos.

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