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progress in Natural Science:Materials International 2007年第6期17卷 733-738页

作者： Jiang Xingpeng1, li Yin2, Meng Ya3 and Meng Dazhi2(1. National Laboratory of pattern recognition,institute of automation, Chinese Academy of Sciences, beijing 100080, china 2. college of Applied Sciences, beijing University of technology, beijing 100022, china 3. School of Science, beijing institute of technology, beijing 100081, china) National Laboratory of pattern recognition Institute of Automation Chinese Academy of Sciences Beijing 100080 China National High Magnetic Field Laboratory Florida State University 1800 East Paul Dirac Drive Tallahassee Florida 32306 USA

Using a small quantity of DNA molecules and little experimental time to solve complex problems successfully is a goal of DNA computing. Some Np-hard problems have been solved by DNA computing with lower time complexity than conventional computing. However, this advantage often brings higher space complexity and needs a large number of DNA encoding molecules. One example is graph coloring problem. Current DNA algorithms need exponentially increasing DNA encoding strands with the growing of problem size. Here we propose a new DNA algorithm of graph coloring problem based on the proof of four-color theorem. This algorithm has good properties of needing a relatively small number of operations in polynomial time and needing a small number of DNA encoding molecules (we need only 6r DNA encoding molecules if the number of regions in a graph is r).

关键词： DNA computing Np-hard problem graph coloring problem.

Synthesis and thermodynamic analysis of nano-La2O3

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progress in Natural Science:Materials International 2007年第7期17卷 838-844页

作者： liu lili~(1,2) Tang Jie~2 li Yuxiang~1 zhang Mei~(1**) Wang Xidong~(1,3) (1.department of physical Chemistry,University of Science and technology beijing,beijing 100083,china 2.National institute for Materials Science,Segen 1-2-1,Tsukuba 305-0047,Japan 3.college of Engineering,beijing University,beijing 100871,china) department of physical Chemistry University of Science and Technology Beijing Beijing 100083 China

The thermodynamic parameters of La（NO3）3and La（OH）3are evaluated and the thermodynamics of nano-La2O3syn- thetic process is *** the base of thermodynamic analysis,La2O3nano-powders are prepared by the sol-gel method and the experi- ment scheme is designed by an orthogonal *** dry-gelatin is analyzed with differential thermal analysis/thermo-gravimetric analy- sis（TGA-DTA）and X-ray diffraction *** microstructure of nano-La2O3powders is observed by transmission dectron micro- *** synthetic parameters affecting the average grain size and dispersivity of nano-La2O3particles are experimentally examined and *** the results indicate that nano-La2O3particles well-dispersed are obtained and the average grain size is in the range of 20—50 nm.

关键词： nano-La2O3 sol-gel thermodynamic analysis

Level Set interface treatment and its application in Euler method

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Science china(physics,Mechanics & Astronomy) 2010年第2期53卷 227-236页

作者： WU KaiTeng1,2,HAO li3,WANG Cheng4 & zhang li1,2 1 Numerical Simulation Sichuan Higher School Key Laboratory,Neijiang Normal University,Neijiang 641112,china 2 college of Mathematics and Information Science,Neijiang Normal University,Neijiang 641112,china 3 college of Science,beijing University of Civil Engineering and Architecture,beijing 100044,china 4 State Key Laboratory of Explosion Science and technology,beijing institute of technology,beijing 100081,china Neijiang Normal University Numerical Simulation Sichuan Higher School Key Laboratory Neijiang China (GRID:grid.464376.4) (ISNI:***) Neijiang Normal University College of Mathematics and Information Science Neijiang China (GRID:grid.464376.4) (ISNI:***) beijing University of Civil Engineering and Architecture College of Science Beijing China (GRID:grid.411629.9) (ISNI:***) beijing institute of technology State Key Laboratory of Explosion Science and Technology Beijing China (GRID:grid.43555.32) (ISNI:***)

Level Set interface treatment method is introduced into Euler method,which is employed for interface treatment method for multi-materials. Combined with the ghost fluid method,the moving interface is tracked. Fifth-order WENO spatial discretization and third-order TVD runge-Kutta time discretization methods are used. Shock-wave action on bubble,implosion and velocity field Shock effect bubbles; implosion and velocity field are simulated by means of LS-MMIC3D programmed by C++. Nu-merical results show that the Level Set interface treatment method is effective and feasible for multi-material interface treatment in comparison with the WENO method.

关键词： Euler method Level Set method shock-wave action on bubble implosion numerical simulation

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Analysis of moment invariants under general linear transformation

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Science china(Information Sciences) 2010年第7期53卷 1305-1311页

作者： DIAO LuHong1, li Hua2, zhang Sen1 & liU Lei1 1college of Applied Sciences, beijing University of technology, beijing 100124, china 2National Center of Intelligent Computing, institute of Computing technology, Chinese Academy of Science, beijing 100080, china college of Applied Sciences Beijing University of Technology National Center of Intelligent Computing Institute of Computing Technology Chinese Academy of Science

This paper presents the necessary and sufficient condition of moment invariants under general linear transformation. Based on this condition, arbitrary order and dimensional moment invariant sets can be constructed. D... 详细信息

关键词： moment invariants independence linear transformation

Monaural voiced speech segregation based on elaborate harmonic grouping strategies

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Science china(Information Sciences) 2011年第12期54卷 2491-2500页

作者： liU WenJu 1 , zhang Xueliang 1 , JIANG Wei 1 , li peng 2 & XU Bo 2 1 National Laboratory of pattern recognition, institute of automation, Chinese Academy of Sciences, beijing 100190, china 2 Digital Media Content technology research Center, institute of automation, Chinese Academy of Sciences, beijing 100190, china National Laboratory of pattern recognition Institute of Automation Chinese Academy of Sciences

In this paper, an enhanced algorithm based on several elaborate harmonic grouping strategies for monaural voiced speech segregation is proposed. Main achievements of the proposed algorithm lie in three aspects. Firstly, the algorithm classifies the time-frequency (T-F) units into resolved and unresolved ones by carrier-to-envelope energy ratio, which leads to more accurate classification results than by cross-channel correlation. Secondly, resolved T-F units are grouped together according to minimum amplitude principle, which has been verified to exist in human perception, as well as the harmonic principle. Finally, "enhanced" envelope autocorrelation function is employed to detect amplitude modulation rates, which helps a lot in reducing half-frequency error in grouping of unresolved units. Systematic evaluation and comparison show that performance of separation is greatly improved by the proposed algorithm. Specifically, signal-to-noise ratio (SNr) is improved by 0.96 dB compared with that of previous method. Besides, our algorithm is also effective in improving the pESQ score and subjective perception score.

关键词： computational auditory scene analysis voiced speech separation harmonistic principle minimum amplitude principle elaborate harmonic grouping strategies

A new policy to solve routing conflicts in shuffle-exchange networks

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Science china(Information Sciences) 2011年第7期54卷 1512-1523页

作者： GE FangBin 1,ZHAO Min 1,zhang Tao 1 & WANG JianXin 2 1 college of Command automation pLA University of Science and technology,Nanjing 210007,china 2 institute of china Electronic System Engineering,beijing 100039,china college of Command automation pLA University of Science and technology

Batch routing is an important approach for solving routing conflicts in SE (shuffle-exchange) ***,the complexity of batching and the uncertainty of batch size makes this approach *** on sequence division and routing coding concepts,we propose a method for detecting routing conflicts in an SE network,known as dividing detection that is more efficient than the method for window *** addition,a new conjecture relating to routing policies in SE networks is *** is proved using a constructive approach when n re,a new routing scheme for SE networks is *** this scheme,all the input signals can be transfered without conflicts and within two batches,while the efficiency of the batch routing is noticeably improved.

关键词： shuffle-exchange network sequence division routing coding transition sequence educed sequence

Spatio-temporal pattern analysis of single-trial EEG signals recorded during visual object recognition

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Science china(Information Sciences) 2011年第12期54卷 2519-2527页

作者： WANG ChangMing 1 , HU Xiaoping 3 , YAO li 1,2 , XIONG Shi 2 & zhang JiaCai 2 1 National Key Laboratory of Cognitive Neuroscience and Learning, beijing Normal University, beijing 100875, china 2 college of Information Science and technology, beijing Normal University, beijing 100875, china 3 Biomedical Imaging technology Center, Emory University/Georgia institute of technology, Atlanta 30322, USA National Key Laboratory of Cognitive Neuroscience and Learning Beijing Normal University college of Information Science and technology Beijing Normal University

Object discrimination is a fundamental cognitive function for human brains. In this study, we utilized an analysis approach for single-trial electroencephalography (EEG) to analyze the spatio-temporal activation patterns of visual objects processing in human brains, and attempted to apply it to discriminate different visual objects. The spatial patterns were respectively extracted from scalp EEG and the reconstructed cortical sources, while the experiment participants were perceiving 4 different categories of visual objects (faces, buildings, cats and cars). By classifying the patterns extracted from single-trial EEG, the presented visual objects could be discriminated by a computer, and the classification accuracies may provide a quantitative index to evaluate the spatial differences of the brain activations related to different visual objects. Our results demonstrated that the spatial patterns on both the scalp and the sources levels resulted in higher classification accuracies than chance rate. We also examined the classification results using temporally non-overlapping time intervals of different event-related potential (Erp) components. The temporal changes of classification accuracies may reflect the temporal distribution of the discriminative information in the EEG responses. The present pattern extraction and classification methods may compose a computational model for single-trial EEG data analysis in investigations of the spatio-temporal activation patterns for object recognition. These spatio-temporal patterns in EEG may be useful to identifying the discriminative spatial areas and time stages to improve the accuracies and efficiencies of object discrimination. In addition, investigating and utilizing humans'cognitive mechanisms of object recognition may improve computers' processing efficiency of visual information.

关键词： EEG spatio-temporal pattern object recognition single-trial analysis visual information processing

Fluorescence dynamics of interactions between polyamide pypypyβDp and DNA

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Science china Chemistry 2006年第1期49卷 75-80页

作者： zhang Huijuan1,2, WANG Jin3, WU Yishi1, YUAN Gu3, AI Xicheng1, WANG li4 & zhang Jianping1 1. State Key Laboratory for Structural Chemistry of Unstable and Stable Species, institute of Chemistry, Chinese Academy of Sciences, beijing 100080, china 2. School of life Science and technology, beijing institute of technology, beijing 100081, china 3. college of Chemistry and Molecular Engineering, peking University, beijing 100080, china 4. Center for Condensed Matter physics, institute of physics, Chinese Academy of Sciences, beijing 100080, china Correspondence should be addressed to Ai Xicheng and zhang Jianping State Key Laboratory for Structural Chemistry of Unstable and Stable Species Institute of Chemistry Chinese Academy of Sciences Beijing China School of life Science and technology Beijing Institute of Technology Beijing China college of Chemistry and Molecular Engineering Peking University Beijing China Center for Condensed Matter physics Institute of Physics Chinese Academy of Sciences Beijing China

The photophysical properties of the polyamide pypypyβDp (ppp) were investigated by means of steady-state absorption and fluorescence spectroscopies, as well as time-resolved fluo-rescence spectroscopy. It was found that the excited-state properties of ppp are very sensitive to solvents. In TKMC buffer ppp exhibited weak fluorescence with a decay time constant of 16 ps, while with the decrease of the solvent polarity ppp showed the blue-shifted peak position, increased inten-sity and lengthened life-time for its fluorescence behavior. In the presence of calf thymus DNA, it was observed that the fluorescence intensity was enhanced and the fluorescence lifetime increased from 16 to 32 ps for ppp, which verified that ppp bound into the minor groove of DNA duplex.

关键词： polyamide (ppp), calf thymus DNA (ctDNA), time-resolved fluorescence spectroscopy, recognition dynamics.

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Formation of super-concentrated hydrochloric acid in the third phase in tertiary amine N235-ptCl_6^(2-)-HCl system and its influences on the pt microemulsion extraction

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Science china Chemistry 2009年第11期52卷 1825-1834页

作者： HUANG Kun1,CHEN Jing1,zhang ChengFeng1,2,li ZhiHong3,pAN QingHua1,SUN yan1,liU ShaoXuan1,liU XueXin2,li WeiHong1,yanG ZhanLan1,WENG ShiFu1,HU TianDou3,XU YiZhuang1 & WU JinGuang1 1 college of Chemistry and Molecular Engineering,peking University,beijing 100871,china 2 institute of Chemistry,Chinese Academy of Sciences,beijing 100190,china 3 institute of High Energy physics,Chinese Academy of Sciences,beijing 100049,china college of Chemistry and Molecular Engineering Peking University Beijing China institute of Chemistry Chinese Academy of Sciences Beijing China institute of High Energy physics Chinese Academy of Sciences Beijing China

In this paper,we have investigated the formation of the third-phase in tertiary amine(N235)-ptCl62--HCl system and the microscopic phase structural evolution of platinum-loaded organic phases before and after the occurrence of the *** third-phase is characterized by various spectroscopic techniques,and the small angle X-ray scattering(SAXS) experiments demonstrate the appearance of nano-aggregates,i.e.,water-in-oil reversed micelles,in the third *** experimental results indicate that(1) formation of the third phase is related to the aggregation behaviors of nano-reversed micelles in which a super-concentrated hydrochloric acid formed with the H+ to H2O molar ratio being much higher than that of the conventional 37 wt% saturated hydrochloric acid.(2) The occurrence of the super-concentrated HCl results in a great amount of H+ and Cl-ions enriched and confined within the nano-water pools of W/O reversed micelles in third ***,the coordination behaviors of platinum complex ions in that super-concentrated hydrochloric acid are very different from their corresponding behaviors in bulk aqueous *** is possible that H+ ions participate in the formation of such complexes as HmptCl6z+ in the super-concentrated hydrochloric acid.(3) The relative contents of various HmptCl6z+ complexes are different corresponding to the H+ ion concentrations in confined nanowater *** association ability of the acidified tertiary amine N235 molecules(r3NH+) with various HmptCl6z+ complexes plays an important role in affecting the platinum extraction behaviors.

关键词： solvent extraction third phase super-concentrated hydrochloric acid tertiary amine platinum

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