检索结果-南通市图书馆

science china(Information sciences) 2012年第10期55卷 2301-2317页

作者： ZHANG Zhe 1,2,3,ZHANG bingChen 1,2,JIANG ChengLong 1,2,3,XIANG Yin 1,2,HONG Wen 1,2 & WU YiRong 1,2 1 science and Technology on Microwave Imaging Laboratory,beijing 100190,china 2 institute of Electronics,chinese academy of sciences,beijing 100190,china 3 graduate University,chinese academy of sciences,beijing 100190,china 1. science and Technology on Microwave Imaging Laboratory Beijing 100190 China 2. institute of Electronics Chinese Academy of Sciences Beijing 100190 China 3. graduate University Chinese Academy of Sciences Beijing 100190 China

Sparse microwave imaging radar is a newly developed concept of microwave imaging system,which tries to combine the traditional radar imaging system with sparse signal processing theories,achieving the aim of reducing the complexity of microwave imaging systems and enhancing the system *** this paper,we introduce some basic concepts of sparse signal processing theory,and then apply it to the traditional radar imaging system to get the mathematical model of sparse microwave imaging *** analyze the factors that determine the performance of sparse microwave imaging radar,including scene,waveform and *** to the radar model,we analyze how these factors influence the radar system and how to optimize *** results of the sparse microwave imaging radar system are also provided.

关键词： sparse microwave imaging radar synthetic aperture radar compressive sensing Lq regularization waveform design

Scan chain design for shift power reduction in scan-based testing

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science china(Information sciences) 2011年第4期54卷 767-777页

作者： LI Jia 1,HU Yu 2 & LI XiaoWei 2 1 The school of Software,Tsinghua University,beijing 100084,china 2 The institute of Computing Technology,chinese academy of sciences,beijing 100190,china 1. The school of Software Tsinghua University Beijing 100084 China2. The Institute of Computing Technology Chinese Academy of Sciences Beijing 100190 China

Test power of VLSI systems has become a challenging issue *** scan shift power dominates the average test power and restricts clock frequency of the shift phase,leading to excessive thermal accumulation and long test *** paper proposes a scan chain design technique to solve the above *** on weighted transition metric (WTM),the proposed extended WTM (EWTM) that is utilized to guide the scan chain design algorithm can estimate the scan shift power in both the shift-in and shift-out ***,the wire length overhead of the proposed scan chain design can also be reduced by the proposed distance of EWTM (DEWTM) *** results confirm that the proposed approach can significantly reduce scan shift power with low wire length overhead.

关键词： low power DfT scan-based testing test power reduction scan chain design

Development of environmental monitoring satellite systems in china

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science china Earth sciences 2010年第S1期53卷 1-7页

作者： LI guoPing1 & CAO ChunXiang2 1 school of Earth and Space sciences,Peking University,beijing 100871,china 2 State Key Laboratory of Remote Sensing science,Jointly Sponsored by the institute of Remote Sensing Applications of chinese academy of sciences and beijing Normal University,beijing 100101,china 1. school of Earth and Space sciences Peking University Beijing 100871 China2. State Key Laboratory of Remote Sensing Science Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University Beijing 100101 China

With the increase in global environmental problems,the necessity and urgency of remote sensing technology being applied to environmental monitoring has been widely recognized around the *** has launched the environment and disaster monitoring and forecasting small satellite constellation HJ-1A/B and the FY3 atmosphere and environmental satellite,but they still cannot fully satisfy requirements for environmental *** paper summarizes the current status of satellite environmental monitoring in china and the existing problems of inadequate load design and low data utilization efficiency,and discusses the demand for environmental monitoring *** on the development of foreign satellite systems for environmental monitoring,the future development and key tasks of the environmental monitoring satellite system in china is discussed,as are some related initiatives.

关键词： environmental satellite environmental monitoring global climate change specialty load satellite system

EXPLORATION OF TCM MASTERS KNOWLEDGE MINING

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Journal of systems science & Complexity 2008年第1期21卷 34-45页

作者： Xijin TANG Nan ZHANG Zheng WANG institute of systems science Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100080 China.

Traditional chinese medicine （TCM） has a rich knowledge about human health and disease by its special way evolved along a very long history. As modern medicine is achieving much progress, arguments and disputes toward TCM never end. To avoid losing precious knowledge of living TCM masters, endeavors have been engaged to systematic collection of those knowledge of TCM masters, such as their growth experiences, effective practical cases toward diseases and typical therapeutic principles and methods. Knowledge mining methods have been expected to explore some useful or hidden patterns to unveil some mysteries of the TCM system. In the paper, some computerized methods are applied toward those collected materials about some living TCM masters in china mainland to show a different way of exposing essential ideas of those TCM masters by correspondence visualization which aims to help people understand TCM holistic views toward disease and body, and facilitate tacit knowledge transfer and sense-making of the essence of TCM. The work is one kind of qualitative meta-synthesis of TCM masters＇ knowledge.

关键词： Idea map knowledge mining qualitative meta-synthesis traditional chinese medicine.

L^2-Algebraic Decay Rate for Transient Birth-Death Processes

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chinese Annals of mathematics,Series B 2012年第4期33卷 583-594页

作者： Lijuan CHENG1 Yingzhe WANG2 1Laboratory of mathematics and Complex systems, the Ministry of Education of china school of Mathe-matical sciences, beijing Normal University, beijing 100875, china. 2Laboratory of mathematics and Complex systems, the Ministry of Education of china school of Mathematical sciences, beijing Normal University, beijing 100875, china. Laboratory of mathematics and Complex systems the Ministry of Education of China school of Mathematical sciences Beijing Normal University Beijing China

This paper is a continuation of the study of the algebraic speed for Markov processes. The authors concentrate on algebraic decay rate for the transient birth-death processes. According to the classification of the boundaries, a series of the sufficient conditions for algebraic decay is presented. To illustrate the power of the results, some examples are included.

关键词： Transient Birth-death processes Algebraic decay

Profitless delays for extinction in nonautonomous Lotka-Volterra system

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Communications in Nonlinear science and Numerical Simulation 2001年第4期6卷 210-216页

作者： Shengqiang LIU and Lansun CHEN academy of mathematics and system sciences, chinese academy of sciences, beijing 100080, china e-mail: Lsq@math03. math. ac. cn academy of mathematics and system sciences Chinese Academy of Sciences Beijing 100080 China

We study the delayed periodic n-species Lotka-Volterra systems where the growth rate of each species is not always positive. The sufficient conditions for the extinction that are independent of the delays are obtained. Some known results are improved and generalized. Our results suggest that under some conditions, the introduction and the variance of the time delays can be both harmless and profitless. Discussion about the effect of time delays on the extinction of the system is also advanced.

关键词： competitive Lotka-Volterra system periodic profitless delays extinction

Fluorescence response of hypocrellin B to the environmental changes in a mimic biological membrane——liposome

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science china Chemistry 2004年第4期47卷 335-339页

作者： JIN Xuanye1,2, ZHAO Yuewei1, XIE Jie1 & ZHAO Jingquan1 1. CAS Key Laboratory of Photochemistry, Center for Molecular science, institute of Chemistry, chinese academy of science, beijing 100080, china 2. school of Earth sciences and Resources, china University of Geosciences, beijing 100083, china 1. CAS Key Laboratory of Photochemistry Center for Molecular Science Institute of Chemistry Chinese Academy of Science 100080 Beijing China 2. school of Earth sciences and Resources China University of Geosciences 100083 Beijing China

Liposome is well known as not only a drug-delivery system but also a simple model for biological membranes. It was reported that fluorescence properties of hypocrellins were changeable over some extreme pH values. In the current work, the effects of the microenvironments on the fluorescence properties of HB in liposome, including approximately physiological range of pH values pH = 6.0-8.0, concentration of cholesterols and ionic strength of the solution, were studied. It was found that the fluorescence intensity of HB was sensitive to and also regulated by the microenvironments. When concentration of cholesterols and ionic strength keep invariable in PBS solution, there exists the maximum for the fluorescence of HB-liposome at pH 7.4 while the minimum for that of HB at pH 7.0. In addition, when pH value keeps constant (7.2), there exists the maximum at the ionic strength of 0.12 mol/kg while that at the concentration of 6×10?4 mol/L for cholesterols. On the other hand, in PBS solution, the lower the ionic strength is, the higher the fluorescence intensity is. The environment-sensitive fluorescence may be potentially applicable to probe some specific environmental features in cells or tissues.

关键词： microenvironment hypocrellin B liposome fluorescence

POSITIVE SOLUTIONS FOR WEAKLY COUPLED NONLINEAR ELLIPTIC systems

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Acta Mathematica Scientia 2010年第5期30卷 1577-1592页

作者：龙静杨健夫 Wuhan institute of Physics and mathematics Chinese Academy of Sciences graduate school Chinese Academy of Sciences Department of mathematics Jiangxi Normal University

In this article, we consider the existence of positive solutions for weakly coupled nonlinear elliptic systems {-△u＋u=（1＋a（x））｜u｜P-1u＋μ｜u｜a-2u｜v｜β＋λv in Rn,-△u＋u=（1＋b（x））｜v｜p-1v＋μ｜u｜a｜v｜β-2v＋λu in Rn To find nontrivial solutions, we first investigate autonomous systems. In this case, results of bifurcation from semi-trivial solutions are obtained by the implicit function theorem. Next, the existence of positive solutions of problem （0.1） is obtained by variational methods.

关键词： Elliptic system in RN positive solution bifurcation variational method

A CLASS OF GENERALIZED MULTIPROCESSOR SCHEDULING PROBLEMS

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systems science and Mathematical sciences 2000年第4期13卷 385-390页

作者： YANG Xiaoguang (Laboratory of Management, Decision and Information system, institute of systems science, academy of mathematics and systems science, chinese academy of sciences, beijing 100080, china) 中科院系统科学所管理、决策与信息系统开放实验室北京 100080

The paper discusses a class of generalized multiprocessor scheduling problems which is to arrange some independent jobs on almost identical processors. Different from the classical multiprocessor scheduling, each job may only be processed by some processors, not all. In this paper, we first prove that the problems of minimization makespan and minimization total weighted completion time can be solved by the polynomial algorithms if all processing time are unit time. Then for arbitrary processing time, we try to analyze the worst performance of list schedule (LS) method and longest processing time(LPT) method when there are only two machines involved. We show that the bounds for LS and LPT are exactly two.

关键词： Unit execution time polynomial algorithm bound.

Phase relationship of complex multi-component system in chromate cleaner production

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Progress in Natural science:Materials International 2007年第7期17卷 845-850页

作者： Ge Xinlei~1 Wang Xidong~(1,3**) Zheng Shili~2 Zhang Mei~1 Zhang Yi~2 (1.Department of Physical Chemistry,University of science and Technology beijing,beijing 100083,china 2.institute of Process Engineering,chinese academy of sciences,beijing 100080,china 3.College of Engineering,Peking University,beijing 100871,china) [a]Department of Physical Chemistry University of Science and Technology Beijing Beijing China [b]College of Engineering Peking University Beijing China [c]institute of Process Engineering Chinese Academy of Sciences Beijing China

The phase relationships of the complex multi-component systems in the liquid-phase oxidization and separation process related with the chromate cleaner production are investigated theoretically and *** phase diagram of main system Fe- Cr2O4-KOH-O2of oxidization process and the relationship of its standard Gibbs free energy change with temperature are calculated.A se- ries of phase diagrams of the separation process at different temperatures,such as K（Na）OH-K（Na）2CrO4-H2O,KOH-KAlO2-H2O, K（Na）OH-K（Na）2CO3-H2O,K（Na）OH-K（Na）HCO3-H2O and K（Na）HCO3-K（Na）2CrO4-H2O have also been *** ex- periments are carried out to verify the calculated *** results showed that the sub-molten salt media are suitable for the oxidization and separation processes;FeCr2O4can be oxidized across a wide range of temperature;K（Na）2CrO4can be separated from K（Na）AlO2system at appropriate temperature and proper concentration;the crystallization of carbonate is easier than that of K（Na）2CrO4.

关键词： chromite chromate system thermodynamics calculation phase diagram