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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,{2., jinan 2.0100, china 2. Department of Computer, shandong Economic university, jinan 2.0014, china) [a]school of Computer science and Technology Shandong University Jinan China [b]Department of Computer Shandong Economic University Jinan 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 2.5 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.

DFT study of the conductance of molecular wire:The effect of coupling geometry and intermolecular interaction on the transport properties

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science china Chemistry 2006年第6期49卷 492-498页

作者： QI Yuanhua1,2. GUAN Daren1 & LIU Chengbu1 1. Institute of Theoretical Chemistry, shandong university, jinan 2.0100,{2. 2. school of Physics and Microelectronics, shandong university, jinan 2.0061,{2. 1. Institute of Theoretical Chemistry Shandong University Jinan 250100 China 2. school of Physics and Microelectronics Shandong University Jinan 250061 China

The density functional theory (DFT) combining with the non-equilibrium Green functions (NEGF) method is applied to the study of the electronic transport properties for a Di-thiol-benzene (DTB) molecule coupled to two Au(111) surfaces. The dependence of the transport properties on the bias, the coupling geometry of the molecule-electrode interface, and the intermolecular interaction are examined in detail. The results show that the existence of the hydrogen atom at the end of the DTB molecule would significantly decrease the transmission coefficients, and then the differential conductance (dI/dV). By changing the position of the DTB molecule located between two electrodes a maximum value of calculated current is observed. It is also found that the intermolecular interaction will strongly influence the transport properties of the system studied.

关键词： non-equilibrium Green functions method, transmission spectrum, the molecular projected selfconsistent Hamiltonian, projected density of state.

Adaptive bidirectional diffusion for image restoration

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science china({2. sciences) 2010年第12期53卷 2452-2460页

作者： FU ShuJun 1,2.& ZHANG CaiMing 1 1 school of Computer science and Technology,{2., jinan 2.0101, china 2.school of Mathematics,{2., jinan 2.0100, china 1. school of Computer science and Technology Shandong University Jinan 250101 China2. School of Mathematics Shandong University Jinan 250100 China

A large number of applications in image processing and computer vision depend on image quality. In this paper, combining the forward diffusion with the backward diffusion by different weights, we present an adaptive bidirectional diffusion method for image denoising and deblurring simultaneously. Further, we introduce a gradient factor into the data fidelity term, which forms a spatially varying constraint and allows a better restoration of image edges and fine details. In order to obtain a stable solution, we develop a numerically stable scheme and give its theoretical analysis. Finally, we show advantages of this method in deblurring edges, denoising and restoring fine details of image compared with other related methods in experiments.

关键词： image restoration bidirectional diffusion inverse diffusion anisotropic diffusion stabilizing scheme spatially varying constraint

Stability for a class of nonlinear time-delay systems via Hamiltonian functional method

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science china({2. sciences) 2012年第5期55卷 1218-1228页

作者： YANG RenMing 1,2.& WANG YuZhen 1 1 school of Control science and Engineering,{2. university,jinan 2.0061,china 2.{2. Jiaotong university,jinan 2.002.,china 1. school of Control science and Engineering Shandong University Jinan 250061 China2. Shandong Jiaotong University Jinan 250023 China

This paper investigates the stability of a class of nonlinear time-delay systems via Hamiltonian functional method,and proposes a number of new results on generalized Hamiltonian realization (GHR) and stability analysis for this class of ***,the concept of GHR of general nonlinear time-delay systems is proposed,and several new GHR methods are ***,based on the new GHR methods obtained,the stability of time-delay systems is investigated,and several delay-dependent sufficient conditions in term of matrix inequalities are derived for the stability analysis by constructing suitable Lyapunov-Krasovskii (L-K) ***,an illustrative example shows that the results obtained in this paper have less conservatism,and work very well in the stability analysis of some nonlinear time-delay Hamiltonian systems.

关键词： nonlinear time-delay systems stability Hamiltonian functional method generalized Hamiltonian realization

H∞ control of a class of nonlinear Hamiltonian descriptor systems

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science china({2. sciences) 2010年第11期53卷 2195-2204页

作者： SUN LiYing1,2.& WANG YuZhen1 1school of Control science and Engineering,{2., jinan 2.0061, china 2.0} of science, university of jinan, jinan 2.002., china 1. school of Control science and Engineering Shandong University Jinan 250061 China2. School of Science University of Jinan Jinan 250022 China

This paper studies the stabilization and H∞ control of a class of nonlinear Hamiltonian descriptor systems. Firstly, based on the structural characteristic of the nonlinear Hamiltonian descriptor system, an equivalent nonlinear dissipative Hamiltonian differential-algebraic system is obtained by using restricted system equivalent theory. With the dissipative form, the stabilization problem is then discussed for the nonlinear Hamiltonian descriptor systems, and an H∞ controller is designed. Finally, simulations on a nonlinear circuit system are given.

关键词： nonlinear Hamiltonian descriptor systems stabilization H∞ control

Repetitious-Hot-Pressing Technique in Hot-Pressing Process

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Journal of Materials science & Technology 2003年第5期19卷 486-488页

作者： Shixue SONG, Xing AI, Wei GAO and Jun ZHAO1)school of Mechanical Engineering, shandong university, {2. 2.0061, china2.school of science, {2. university, {2. 2.002., china school of Mechanical Engineering Shandong University Jinan 250061 China school of science Jinan University Jinan 250022 China

A new pressing method was proposed for hot-pressing process. Experimental results indicated that the porosity in Al2.3/TiC/ Ni/Mo (hereafter called AI2.3/TiC composite) composite compacts decreases by 6% after adopting this new technique, compared to traditional hot-pressing technique under the same sintering temperature. The flexural strength and Vicker hardness increase from 883 MPa to 980 MPa and from 16 GPa to 2..1 GPa, respectively. A theoretical model was given to analyze the densification mechanism of the composite in the process of repetitious-hot-pressing.

关键词： Hot-pressing sintering Repetitious-hot-pressing sintering Composite

The influence of laser pulse on the photoabsorption spectra of Li atom in strong external field

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science china(Physics,Mechanics & Astronomy) 2006年第2期49卷 178-186页

作者： WANG Dehua1 & LIN Shenglu2.1. school of Physics and Electronic Engineering, Yantai Normal university, Yantai 2.402.,{2. 2. Department of Physics, shandong Normal university, jinan 2.0014,{2. 1. school of Physics and Electronic Engineering Yantai Normal University Yantai 264025 China 2. Department of Physics Shandong Normal University Jinan 250014 China

Using the time-dependent perturbation theory and the calculation formula of the single- and double-pulse absorption spectra of the atom in strong external fields, we calculate the single- and double-pulse absorption spectra of Li atom in strong magnetic field for different pulse widths. The results show that a pulse of some width can reduce the contribution of the short period closed orbits and eliminate the contribution of the long period orbits. Compared with the single-pulse absorption spectra, we found that for some phase differences, the double-pulse laser absorption spectra are strengthened; while for others, they are reduced. Therefore, we can use the pulse laser to control the oscillation of the absorption spectra and obtain the optimization object.

关键词： laser pulse closed orbit absorption spectra.

Diffusion and Oxidation Wear of PCBN Tool based on Thermodynamics

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Journal of Wuhan university of Technology(Materials science) 2010年第2期25卷 265-271页

作者：邵芳 Binzhou Vacational College school of Mechanical Engineering Shandong University

The rules of diffusion wear and oxidation wear for PCBN cutting tools were analyzed based on thermodynamics theory. Dissolution concentrations in typical normal workpice materials of PCBN tool material at different temperature were then calculated. Diffusion reaction rules in high temperature were developed and analyzed using the Gibbs free energy criterion. The machining tests were conducted using the PCBN tools at different cutting speeds of 50, 95,100 and 180 m/min, feed of 0.1, 0.2.and depth of cut of 0.1, 0.8, 1, and 1.5 mm respectively on a PUMA300LM numerically-controlled lathe. It was found that the theoretical results were uniform with the experimental data, and the results will provide useful references for tool material design and selection.

关键词： thermodynamics PCBN tool diffusion wear oxidation wear

Intermediate processes and critical phenomena: Theory, method and progress of fractional operators and their applications to modern mechanics

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science china(Physics,Mechanics & Astronomy) 2006年第3期49卷 257-272页

作者： XU Mingyu1 & TAN Wenchang2.1. Institute of Applied Mathematics, school of Math & System science,{2., jinan 2.0100, china 2. State Key Laboratory of Turbulence and Complex Systems & Department of Mechanics and Engineering science, Peking university, Beijing 100871, china 1. Institute of Applied Mathematics School of Math & System Science Shandong University Jinan 250100 China 2. State Key Laboratory of Turbulence and Complex Systems & Department of Mechanics and Engineering science Peking University Beijing 100871 China

From point of view of physics, especially of mechanics, we briefly introduce fractional operators (with emphasis on fractional calculus and fractional differential equa- tions) used for describing intermediate processes and critical phenomena in physics and mechanics, their progress in theory and methods and their applications to modern me- chanics. Some authors’ researches in this area in recent years are included. Finally, prospects and evaluation for this subject are made.

关键词： fractional operators,intermediate processes,critical phenomena,modern mechanics