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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, jinan 250014, china 2. Department of Mathematics and Physics, shandong Institute of Architecture and Engineering, jinan 250014, china Department of Physics Shandong Normal University Jinan China Department of Mathematics and Physics Shandong Institute of Architecture and Engineering 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.

Extraction of Surface Roughness from the Central δ-peak of Light Scattering Using a Multi-wavelength Ar~+ Laser

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Chinese Journal of Lasers 2000年第3期9卷 22-27页

作者： LIU Deli QI Dongping CHENG Chuanfu (Department of Physics, shandong Normal University, jinan 250014, china) 山东师范大学山东济南

In this paper, a new light scattering method for measuring t he roughness of random surfaces is proposed. The method is based on the relation between the specularly reflected intensity I s, i.e., the central δ-peak intensity and wave vector component k z. The linear fit of the logarithm graph of the normalized central δ-peak intensity I sr versus k-2 z, whose variation is induced by changing illuminating wavelength, gives the square of the surface roughness w. The roughnesses of 6 silicon backside samples were measured.

关键词： random surface roughness light scattering multi-wavelength

MECHANICAL PROPERTIES OF Al-Li ALLOY 8090 AT CRYOGENIC TEMPERATURES

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Acta Metallurgica Sinica(English Letters) 1993年第2期6卷 78-80页

作者： SUN Dongsheng LI Fengzhao ZHANG Gang shandong Polytechnic University,jinan,china Lecturer,Centre of Materials Testing and Analysis,shandong Polytechnic University,jinan 250014,china shandong Polytechnic Univ Jinan China

Cryogenic strength,ductility and toughness of AI-Li alloy 8090 were found to be superior to those at ambient temperature,and up to optima at about 20 *** aging regimes may only influence on its cryogenic yield strengt... 详细信息

关键词： Al-Li alloy cryogenic mechanical property work hardening alloy 8090

Prediction for RNA planar pseudoknots

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Progress in Natural Science:Materials International 2007年第6期17卷 717-724页

作者： Li Hengwu1,2, Zhu Daming1, Liu Zhendong1 and Li Hong2(1. School of Computer Science and Technology, shandong University, jinan 250100, china 2. Department of Computer, shandong Economic University, jinan 250014, china) School of Computer Science and Technology Shandong University Jinan 250100 China Department of Computer Shandong Economic University Jinan 250014 China

Based on m-stems and semi-extensible structure, a model is presented to represent RNA planar pseudoknots, and corresponding dynamic programming algorithm is designed and implemented to predict arbitrary planar pseudoknots and simple non-planar pseudoknots with O(n4) time and O(n3) space. The algorithm folds total 245 sequences in the Pseudobase database, and the test results indicate that the algorithm has good accuracy, sensitivity and specificity.

关键词： algorithm RNA secondary structure pseudoknot dynamic programming.

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, jinan 250100, china) Xianhong DENG and Yongjun ZHANG (shandong Metallurgical Research Institute, jinan 250014, 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

Phylogenetic origin of Beckmannia (Poaceae) inferred from molecular evidence

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Journal of Systematics and Evolution 2009年第4期47卷 305-310页

作者： ~(1,2)Chong-Mei XU ~3Chang-You QU ~(2,4)Wen-Guang YU ~2Xue-Jie ZHANG ~2Fa-Zeng LI~* 1(Weifang Medical University,Weifang 261053,china) 2(College of Life Sciences,shandong Normal University,jinan 250014,china) 3(shandong Drug and Food Vocational College,Weihai 264400,china) 4(shandong Shengli Co.Ltd.,jinan 250101,china) (Weifang Medical University Weifang 261053 China) (College of Life Sciences Shandong Normal University Jinan 250014 China) (shandong Drug and Food Vocational College Weihai 264400 China) (shandong Shengli Co. Ltd. Jinan 250101 China)

The phylogenetic origin of Beckmannia remains *** genus has been placed within the Chlorideae,Aveneae(Agrostideae),Poeae,or treated as an isolate lineage,*** the present study, we used nuclear internal transcribed spacer(ITS)and chloroplast trnL-F sequences to examine the phylogenetic relationship between Beckmannia and those genera that have assumed to be *** the basis of the results of our studies,the following conclusions could be drawn:(i)Beckmannia and Alopecurus are sister groups with high support;and(ii)Beckmannia and Alopecurus are nested in the Poeae clade with high *** results of our analysis suggest that Beckmannia should be placed in Poeae.

关键词： Aveneae Beckmannia internal transcribed spacer(ITS) phylogeny Poeae trnL-F.

The Existence of Periodic Orbits for Nonlinear Impulsive Differential Systems

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Communications in Nonlinear Science and Numerical Simulation 1999年第1期4卷 50-53页

作者： Xilin FU Jiangang QI and Yansheng LIU (Department of Mathematics, shandong Normal University, jinan 250014, china) Department of Mathematics Shandong Normal University Jinan 250014 China

In this paper, we gave the necessary and sufficient condition for the existence of the periodic solutions of nonlinear impulsive differential systems by using a special function and study the stable properties of suc... 详细信息

关键词： impulsive differential equation periodic orbit stable

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_2O_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_2O_3

An investigation of hadronization mechanism at a Z^0 factory

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Science china(Physics,Mechanics & Astronomy) 2010年第11期53卷 1998-2004页

作者： JIN Yi 1,SI ZongGuo 2,XIE QuBing 2 & YAO Tao 2 1 Department of Physics,University of jinan,jinan 250022,china 2 School of Physics,shandong University,jinan 250100,china Department of Physics University of Jinan Jinan China School of Physics Shandong University Jinan China

We briefly review the hadronization pictures adopted in the LUND String Fragmentation Model (LSFM),Webber Cluster Fragmentation Model (WCFM) and Quark Combination Model (QCM),*** of hadron multiplicity,baryon to meson ratios and baryon-antibaryon flavor correlations,especially those related to heavy hadrons at a Z 0 factory obtained by LSFM and QCM,are reported.

关键词： Z0 factory hadronization model baryon to meson ratio B correlation