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Electronic Structure of New Superconducting Perovskite MgCNi3

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Journal of Materials Science & Technology 2004年第2期20卷 203-205页

作者： Li CHEN, Hua LI and Liangmo MEIphysics and Microelectronic school, shandong university, jinan 25.100, china Department of physics, Linyi Teachers university, shandong 276005, china Phys. and Microelectron. Sch. Shandong Univ. Ji'nan 250100 China Dept. of Phys. Linyi Teachers Univ. Linyi 276005 China

The electronic structures of new superconducting perovskite MgCNi3 and related compounds MgCNi2T (T=Co, Fe, and Cu) have been studied using MS-Xa method. In MgCNi3, the main peak of density of states is located below the Fermi level and dominated by Ni d. From the results of total energy calculations, it was found that the number of Ni valence electron decreases faster for the Fe-doped case than that for the Co-doped case. The valence state of Ni changes from +1.43 in MgCNi2Co to +3.02 in MgCNi2Fe. It was confirmed that Co and Fe dopants in MgCNi3 behave as a source of d-band holes and the suppression of superconductivity occurs faster for the Fe-doped case than that for the Co-doped case. In order to explain the fact that Co and Fe dopants in MgCNi3 behave as a source of d-band holes rather than magnetic scattering centers that quench superconductivity, we have also investigated the effects of electron (Cu) doping on the superconductivity and found that both electron (Cu) doping and hole (Co, Fe) doping quench superconductivity exist. Comparing with the hole (Co) doping, there was no much difference between Cu and Co doping. This suggests that Co and Fe doping do not act as magnetic impurity.

关键词： Electronic structure Superconductivity Density of states

Conduction Properties and Scattering Mechanisms in F-doped Textured Transparent Conducting SnO_2 Films Deposited by APCVD

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Journal of Materials Science & Technology 1997年第1期13卷 50-56页

作者： Deheng ZHANG(Dept. of physics, shandong university, jinan 25.100, china)Honglei MA(Institute of Optoelectronic Materials and Devices, shandong university, jinan 25.100, china) Dept. of physics Shandong University Jinan 250100 China Institute of Optoelectronic Materials and Devices Shandong University Jinan 250100 China

Transparent conducting F-doped texture SnO2 films with resistivity as low as 5× 10-4 Ω ·cm,with carrier concentrations between 3.5 × 1020 and 7× 1020 cm-3 and Hall mobilities from 15.7 to 20.1 cm2/(V/s) have been prepared by atmosphere pressure chemical vapour deposition (APCVD). These polycrystalline films possess a variable preferred orientation, the polycrystallite sizes and orientations vary with substrate temperature. The substrate temperature and fluorine flow rate dependence of conductivity, Hall mobility and carrier conentration fOr the resultingfilms have been obtained. The temperature dependence of the mobiity and carrier concentrationhave been measured over a temperature range 16～400 K. A systematically theoretical analysis on scattering mechanisms for the highly conductive SnO2 films has been given. Both theoretical analysis and experimental results indicate that for these degenerate, polycrystalline SnO2 ：F films in the low temperature range (below 100 K), ionized impurity scattering is main scattering mechanism. However, when the temperature is higher than 100 K, the lattice vibration scattering becomes dominant. The grain boundary scattering makes a small contribution to limit the mobility of the films.

关键词： SnO cm Conduction Properties and Scattering Mechanisms in F-doped Textured Transparent Conducting SnO2 Films Deposited by APCVD

DENSITY OF INTEGERS THAT ARE THE SUM OF FOUR CUBES OF PRIMES

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Chinese Annals of Mathematics,Series B 2001年第2期22卷 233-242页

作者： REN XIUMIN school of Economics, shandong university, jinan 25.100, china. school of Economics Shandong University Jinan 250100 China

Using the circle method and sieves, the author proves that a positive proportion of positive integers can be represented as the sum of four cubes of primes.

关键词： Waring-Goldbach problem Hardy-Littlewood method Sieve methods

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 25.100,china 1. Department of physics University of Jinan Jinan 250022 China2. School of Physics Shandong University Jinan 250100 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

A first-principles study of dihydroazulene as a possible optical molecular switch

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Science china(physics,Mechanics & Astronomy) 2011年第3期Mechanics & Astronomy) .卷 437-441页

作者： XIA CaiJuan1, LIU DeSheng2,3 & LIU HanChen1 1 school of Science, Xi’an Polytechnic university, Xi’an 710048, china 2 school of physics, State Key Laboratory of Crystal Materials, shandong university, jinan 25.100, china 3 Department of physics, Jining university, Qufu 273155, china 1. school of Science Xi’an Polytechnic University Xi’an 710048 China2. School of Physics State Key Laboratory of Crystal Materials Shandong University Jinan 250100 China3. Department of Physics Jining University Qufu 273155 China

By applying nonequilibrium Green's function formalism combined with first-principles density functional theory, we investigate the electronic transport properties of the dihydroazulene optical molecular switch. Three kinds of adsorption sites including the hollow, bridge and top sites are studied. The two forms of this molecule, namely the open form and the closed form, can reversibly switch from each other upon photoexcitation. Their transmission spectra are remarkably distinctive. Theoretical results show that the current of the closed form is always significantly larger than that of the open form for all three adsorption sites, which promises this system as possibly one of the good candidates for optical switches due to its unique advantage, and which may have some potential applications in the future molecular circuit.

关键词： molecular switch nonequilibrium Green’s function electronic transport density functional theory

LEAST-SQUARES MIXED FINITE ELEMENT METHODS FOR NONLINEAR PARABOLIC PROBLEMS

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Journal of Computational Mathematics 2002年第2期20卷 153-164页

作者： Dan-ping Yang (school of Mathematics and System Science, shandong university, jinan 25.100, china) school of Mathematics and System Science Shandong University Jinan 250100

Focuses on the formulation of a number of least-squares mixed finite element schemes to solve the initial boundary value problem of a nonlinear parabolic partial differential equation. Convergence analysis; Informatio... 详细信息

关键词： least-squares algorithm mixed finite element nonlinear parabolic problems convergence analysis

STRUCTURE AND MAGNETIC PROPERTIES OF Fe/Pd COMPOSITIONALLY MODULATED FILMS

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Acta Metallurgica Sinica(English Letters) 1993年第8期6卷 112-115页

作者： ZHANG Lin LIU Yihua shandong university,jinan,china WANG Hao Dongnan university,Nanjing,china engineer,Department of physics,shandong university,jinan 25.100,china shandong Univ Jinan China

Metal Fe/Pd compositionally modulated films(CMFs) were prepared by vapour depo- sition from two sources onto glass substrate under *** modulation and crystal structures of the films were examined by X-ray *** magnetic properties were determined by vibrating sample *** Pd layers in the Fe/Pd CMFs are of fcc structure,and the Fe layer structure transits from bcc into amorphous,state with decreasing thickness of Fe *** dependence of specific saturation magnetization on thickness of Fe layers has also been discussed.

关键词： compositionally modulated films modulated structure specific saturation magnetization

MAXIMUM PRINCIPLE FOR FORWARD-BACKWARD STOCHASTIC CONTROL SYSTEM WITH RANDOM JUMPS AND APPLICATIONS TO FINANCE

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Journal of Systems Science & Complexity 2010年第2期23卷 219-231页

作者： Jingtao SHI·Zhen WU school of Mathematics,shandong university,jinan 25.100,china. school of Mathematics Shandong University

Both necessary and sufficient maximum principles for optimal control of stochastic systemwith random jumps consisting of forward and backward state variables are *** control variableis allowed to enter both diffusion and jump *** result is applied to a mean-varianceportfolio selection mixed with a recursive utility functional optimization *** expressionof the optimal portfolio selection strategy is obtained in the state feedback form.

关键词： Forward-backward stochastic control system maximum principle Poisson random measure recursive utility stochastic optimal control.

The minimal sublinear expectations and their related properties

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Science china Mathematics 2009年第4期52卷 785-793页

作者： JIA GuangYan school of Mathematics, shandong university, jinan 25.100, china 1. school of Mathematics Shandong University Jinan 250100 China

In this paper, we prove that for a sublinear expectation ?[·] defined on L 2(Ω, $ \mathcal{F} $ ), the following statements are equivalent: ? is a minimal member of the set of all sublinear expectations defined on L 2(Ω, $ \mathcal{F} $ )? is linearthe two-dimensional Jensen’s inequality for ? holds.Furthermore, we prove a sandwich theorem for subadditive expectation and superadditive expectation.

关键词： g-expectation Jensen’s inequality linear expectation subadditive expectation sublinear expectation 60H10