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Giant magnetoimpedance effect of multilayered structure(F/SiO_2)_3/Ag/(SiO_2/F)_3 films deposited in a longitudinal magnetic field

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Science china(Technological Sciences) 2010年第3期53卷 287-292页

作者： CHEN WeiPing1,2,SHAO XianYi1,2,FENG ShangShen1,2,XIAO ShuQin3 & LIU YiHua3 1 school of physics and Electronics Engineering,Zhejiang Taizhou university,Taizhou 318000,china 2 Institute of Function Materials for Electronic Information,Zhejiang Taizhou university,Taizhou 318000,china 3 school of physics,shandong university,jinan 250100,china 1. school of physics and Electronics Engineering Zhejiang Taizhou University Taizhou 318000 China2. Institute of Function Materials for Electronic Information Zhejiang Taizhou University Taizhou 318000 China3. School of Physics Shandong University Jinan 250100 China

The soft magnetic properties and giant magnetoimpedance(GMI) effect of the multilayered structure(F/SiO2)3/Ag/(SiO2/F)3(F≡Fe71.5Cu1Cr2.5V4Si12B9) films,which were prepared by radio frequency sputtering without and with a longitudinal magnetic field of about 72 kA/m,are *** results show that the GMI effect almost cannot be detected in the samples deposited without field,whereas,a longitudinal magnetic field applied during deposition process obviously optimizes the soft magnetic properties of the films,and noticeable GMI effect is *** maximum values of the longitudinal and transverse GMI ratios are 45% and 44% at the frequency of 6.81 MHz,*** addition,the dependence of magnetoimpedance ratio,magnetoresistance ratio,magnetoreactance ratio and effective permeability ratio on the frequency has been *** found that the GMI spectrum curves in the longitudinal and transverse cases almost overlap for the field-deposited *** GMI effect is mainly a giant magnetoinductive effect at low *** f >9 MHz,magnetoreactance ratio changes to a negative,i.e.,the property of reactance changes from inductive to capacitive.

关键词： Fe-based soft magnetic alloy as-deposited multilayered films giant magnetoimpedance effect effective permeability magnetic anisotropy

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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 250100, china)Honglei MA(Institute of Optoelectronic Materials and Devices, shandong university, jinan 250100, 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 250100, 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

Optical waveguides in LiNbO_3 and stoichiometric LiNbO_3 crystals by proton exchange

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Science china(physics,Mechanics & Astronomy) 2008年第10期51卷 1479-1488页

作者： LI ShiLing College of physics and Engineering, Qufu Normal university, Qufu 273165, china school of physics and Microelectronics, shandong university, jinan 250100, china 1. College of physics and Engineering Qufu Normal University Qufu 273165 China 2. school of physics and Microelectronics Shandong University Jinan 250100 China

The formation of optical planar waveguides in LiNbO3 and stoichiometric LiNbO3 crystals by proton exchange was reported. The prism-coupling method was used to characterize the dark-line spectroscopy at the wavelength of 633 and 1539 nm, re-spectively. The mode optical near-field outputs from proton-exchanged LiNbO3 and SLN waveguides at 633 nm were presented. The mode field from stoichiometric LiNbO3 (SLN) waveguide is lighter and more uniform than that from LiNbO3 waveguide, which means the quality of the waveguide in SLN crystal is better than that of the LiNbO3 waveguide. For proton-exchanged LiNbO3 waveguides, the evo-lution of the refractive index profile with annealing was presented. The disorder profiles of Nb atoms in proton-exchanged LiNbO3 waveguides were obtained by Rutherford backscattering/channeling technique. It is shown that the longer the exchange time, the larger the displacement of Nb atoms.

关键词： optical waveguide proton exchange LiNbO3 crystal stoichiometric LiNbO3 crystal

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 250100, 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

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 250100, 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

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 250100,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 250100, 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

Electronic structure and magnetism of compound Nd_2Fe_(17)N_3

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Chinese Science Bulletin 1998年第4期43卷 278-282页

作者： JIANG Tao and LI Hua Department of physics, shandong university, jinan 250100, china Department of physics Shandong University Jinan 250100 China

The electronic structure and magnetism of compound Nd\-2Fe 17 N\-3 has been studied with MS_Xα method. It was found that there are negative exchange couplings between Fe(f) and Fe(c) atoms in Nd\-2Fe 17 N x compounds. The interstitial N atoms make the unit cell volume of the compounds increase a little, and hence the strength of negative exchange coupling decreases.

关键词： compounds of R\-2Fe 17 type Curie temperature electronic density of states exchange splitting atomic magnetic moment.