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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 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.

THE GOLDBACH-VINOGRDOV THEOREM WITH THREE PRIMES IN A THIN SUBSET

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Chinese Annals of Mathematics,Series B 1998年第4期19卷 479-488页

作者： LIU JIANYA (Department of Mathematics, shandong university, jinan 250100, china.) 山东大学数学系山东济南

It is proved constructively that there exists a thin subset S of primes, satisfying for some absolute constant c＞0, such that every sufficiently large odd integer N can beLet r be prime, and hi positive integers with (bj, r) = 1,j = 1, 2, 3. It is also proved that, for almost all prime moduli r＜ log- N, every sufficiently large odd integer N = b1 + b2 +ba(modr) can be represented as where c ＞ 0 is an absolute constant.

关键词： Goldbach-Vinogradov theorem Exponential sum Primes Arithmetic progression Mean-value theorem

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

Medical image segmentation using improved FCM

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Science china(Information Sciences) 2012年第5期55卷 1052-1061页

作者： ZHANG XiaoFeng 1,2,ZHANG CaiMing 1,3,4,TANG WenJing 1,2 & WEI ZhenWen 1 1 School of Computer Science and Technology,shandong university,jinan 250101,china 2 School of Information and Electrical Engineering,Ludong university,Yantai 264025,china 3 School of Computer Science and Technology,shandong university of Finance and Economics,jinan 250014.china 4.shandong Province Key Lab of Digital Media Technology,jinan 250014.china 1. School of Computer Science and Technology Shandong University Jinan 250101 China2. School of Information and Electrical Engineering Ludong University Yantai 264025 China3. School of Computer Science and Technology Shandong University of Finance and Economics Jinan 250014 China4. Shandong Province Key Lab of Digital Media Technology Jinan 250014 China

Image segmentation is one of the most important problems in medical image processing,and the existence of partial volume effect and other phenomena makes the problem much more *** C-means,as an effective tool to deal with PVE,however,is faced with great challenges in *** at this,this paper proposes one improved FCM algorithm based on the histogram of the given image,which will be denoted as HisFCM and divided into two *** first phase will retrieve several intervals on which to compute cluster centroids,and the second one will perform image segmentation based on improved FCM *** with FCM and other improved algorithms,HisFCM is of much higher efficiency with satisfying *** on medical images show that HisFCM can achieve good segmentation results in less than 0.1 second,and can satisfy real-time requirements of medical image processing.

关键词： FCM histogram image segmentation medical image processing

Manufacturing Supply Chain Optimization Problem with Time Windows Based on Improved Orthogonal Genetic Algorithm

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武汉理工大学学报 2006年第S1期28卷 254-259页

作者： ZHANG Xinhua (Information Management College,shandong Economic university,jinan 250014.china) Information Management College Shandong Economic UniversityJinan 250014China

Aim to the manufacturing supply chain optimization problem with time windows,presents an improved orthogonal genetic algorithm to solve it. At first,we decompose this problem into two sub-problems (distribution and routing) plus an interface mechanism to allow the two algorithms to collaborate in a master-slave fashion,with the distribution algorithm driving the routing algorithm. At second,we describe the proposed improved orthogonal genetic algorithm for solving giving problem detailedly. Finally,the examples suggest that this proposed approach is feasible,correct and valid.

关键词： manufacturing supply chain time windows orthogonal genetic algorithm

Theoretical studies on the structures and reactivity of stannylenoids *** structures and isomerization of stannylenoid H_2SnLiF

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Chinese Journal of Chemistry 1996年第4期14卷 310-314页

作者： QIU, Hua-Yu DENG, Cong-HaoInstitute of Theoretical Chemistry, shandong university, jinan, shandong 250100, china Institute of Theoretical Chemistry Shandong University Jinan Shandong 250100 China

The structures of singlet stannylenoid H2SnLiF have been examined by ab initio MO theory. Four equilibrium states and three transition states of isomerization reaction are located. The calculation shows that the p-complex 1 is the most stable and experimentally detectable. The other three species, three-membered ring 2, o-complex 3 and tetrahedron 4, are also local minima on the potential energy surface, but are higher in energy.

关键词： Stannylenoid ab initio p-complex structure isomerization reaction

The eigenenergies for ~3S excited states of the helium atom with CFPHGLF method

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Chinese Journal of Chemistry 1997年第1期15卷 13-16页

作者： WANG, Yi-Xuan DENG, Cong-HaoInstitute of Theoretical Chemistry, shandong university, jinan, shandong 250100, china Institute of Theoretical Chemistry Shandong University Jinan Shandong 250100 China

The matrix elements of the correlation function between symmetric potential harmonics were first simplified into the analytical summation of the grand angular momentum. The correlation-function potential-harmonic and generalized Laguerre function method (CFPHGLF) proposed by us recently was then applied to directly solve the Schrodinger equation for n3S(n=2-5) excited states of the helium atom. With only 12 PHs, the convergent eigenenergies of 23S, 33S, 43S and 53S states were 2.17427, 2.06849, 2.03644, 2.02257 Eh, respectively. The errors only were 0.00096, 0.00020, 0.00007, 0.00005 Eh, when compared with the exact Hylleraas variational results respectively.

关键词： Hyperspherical coordinates potential harmonics helium atom

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.

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