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A new class of symmetric periodic solutions of the spatial elliptic restricted three-body problem

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Science china(Physics,Mechanics & Astronomy) 2009年第9期52卷 1404-1413页

作者： XU XingBo1,2 & FU YanNing1 1 Purple Mountain Observatory, chinese academy of sciences, Nanjing 210008, china 2 graduate university of chinese academy of sciences, beijing 100039, china 1. Purple Mountain Observatory Chinese Academy of Sciences Nanjing 210008 China 2. graduate university of chinese academy of sciences Beijing 100039 China

We show that there exists a new class of symmetric periodic solutions of the spatial elliptic restricted three-body problem. In such a solution, the infinitesimal body is confined to the vicinity of a primary and moves on a nearly circular orbit. This orbit is almost perpendicular to the orbital plane of the primaries, where the line of symmetry of the orbit lies. The existence is shown by applying a corollary of Arenstorf's fixed point theorem to a periodicity equation system of the problem. And this existence doesn't require any restriction on the mass ratio of the primaries, nor on the eccentricity of their relative elliptic orbit. Potential relevance of this new class of periodic solutions to real celestial body systems and the follow-up studies in this respect are also discussed.

关键词： periodic orbits spatial restricted three-body problem symmetric orbits averaging

Overview of HBV whole genome data in public repositories and the chinese HBV reference sequences

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Progress in Natural Science:Materials International 2008年第1期18卷 13-20页

作者： Guanghua Wu a,b, Huiguo Ding c, Changqing Zeng b,* a graduate School of chinese academy of sciences, beijing 100049, china b beijing Institute of Genomics, chinese academy of sciences, beijing 101300, china c beijing Youan Hospital, Capital Medical university, beijing 100069, china graduate School of chinese academy of sciences Beijing 100049 China beijing Institute of Genomics Chinese Academy of Sciences Beijing 101300 China beijing Youan Hospital Capital Medical University Beijing 100069 China

The number of Hepatitis B virus (HBV) whole genomic sequences in public nucleotide databases (GenBank, EMBL, and DDBJ) had reached 866 by January 1, 2007. Coming from 46 countries and regions, these sequences were categorized as eight genotypes (A–H). With the statistical and phylogenetic analysis on all available complete genomic data of HBV, we here present an overview of HBV sequences in public databases. From all registered 229 HBV genomes in chinese regions as well as 59 sequencing data from our research group, we report the establishment of reference sequences of HBV strains prevailing in china. These analyses provide clues for the effects of HBV genotypes in host clinical progressions, geographic distribution of the infection, and the viral evolutionary history. Moreover, the viral sequence reference would be helpful in the identiffcation of various HBV mutations. Based on the analysis of various public databases, we suggest that the chinese HBV database with the clinical information should be constructed.

关键词： Public databases HBV genomic sequences Genotype Subtype chinese reference sequences

Possible Energy Network with polygeneration system and CCS for china

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中国科学：技术科学英文版 2010年第1期53卷 33-39页

作者： GAO Lin1,LI Sheng1,2,JIN HongGuang1 & LIN Hu1 1 Institute of Engineering Thermophysics,chinese academy of sciences,beijing 100190,china 2 graduate School of chinese academy of sciences,beijing 100039,china 1. Institute of Engineering Thermophysics Chinese Academy of Sciences Beijing 100190 China2. Graduate School of Chinese Academy of Sciences Beijing 100039 China

On basis of adopting polygeneration systems for power and alternative fuels,capturing CO2 with near zero energy penalties,and storing CO2 on sites,a new kind of Energy Network can integrate energy utilization,CO2 capture,transportation and storage ***-economic analysis of this solution focusing on Inner Mongolia and the Yangtze River Delta districts had been carried with comparison to the chain method for energy utilization and CO2 *** solution can save 21.5% of energy,and reduce 35% of total *** adoption of advanced polygeneration systems contributes 52.2% of the total saved costs,and the integration of energy utilization and CO2 sequestration in the Energy Network contributes 47.8%.From the aspect of CCS,the CO2 sequestration cost in the Energy Network can be as low as 12 $/t due to the lower energy penalties of capture in polygeneration systems and the combination of CO2 source and *** Energy Network exhibits attractive performance on energy saving,costs reduction for CCS,which may be a promising solution for sustainable development of china.

关键词： CO2 capture and storage Energy Network polygeneration system

The influence of moderate ENSO on summer rainfall in eastern china and its comparison with strong ENSO

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chinese Science Bulletin 2008年第5期53卷 791-800页

作者： XUE Feng1 & LIU ChangZheng1,2 1 Institute of Atmospheric Physics, chinese academy of sciences, beijing 100029, china 2 graduate university of chinese academy of sciences, beijing 100049, china chinese Acad Sci Inst Atmospher Phys Beijing 100029 Peoples R China.

The 6 major ENSO events since 1979 are classified into the strong and moderate ENSO based on in-tensity. The composite analysis is performed to reveal the influence of ENSO on East Asian summer monsoon (EASM) and summer rainfall in eastern china. It is shown that the influence is changed with the seasonal cycle in summer, with a weaker influence in June and a stronger influence in August, in-dicating a long lagged effect of ENSO on EASM. Besides, the circulation and rainfall anomalies caused by the strong ENSO are also stronger with an earlier starting time, while the influence of the moderate ENSO is evident in August. The composite summer rainfall in eastern china for the moderate ENSO exhibits a northern rainfall pattern, which is totally different from the classical ENSO-type rainfall pat-tern. Based on the composite analysis, two moderate ENSO years with a similar intensity (i.e., 1995 and 2003) are compared. The result shows that, the response of EASM to the moderate ENSO during June and July is, to a certain degree, modulated by the circulation systems in mid-high latitudes of Eurasia and in the Southern Hemisphere, thereby inducing a different rainfall distribution in eastern china. In comparison with the strong ENSO in 1983, it is further revealed that, the strong ENSO plays a dominant role in summer rainfall anomalies in eastern china as well as in controlling the influence of the other factors on EASM. The strong ENSO is therefore different with the moderate ENSO.

关键词：中国东部海洋气象学厄尔尼诺现象东亚季风降雨

Balanced multiple description subband coding based on multifilter banks

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Science china(Information sciences) 2011年第11期54卷 2359-2372页

作者： WANG Ning 1,LI BaoBin 2 & PENG LiZhong 1 1 LMAM,School of Mathematical sciences,Peking university,beijing 100871,china 2 School of Information Science and Engineering,graduate university of chinese academy of sciences,beijing 100190,china 1. LMAM School of Mathematical Sciences Peking University Beijing 100871 China2. School of Information Science and Engineering Graduate University of Chinese Academy of Sciences Beijing 100190 China

Multiple description coding is one of the source coding techniques to alleviate the problems of packet loss in *** encoder generates several different descriptions of the source and the decoder can produce a useful reconstruction with any received subset of these *** of the earlier works concentrated on redundancy and the average distortion of the single-description reconstructions,which is insufficient to describe the *** this paper,a metric of the coding system,balance eccentric modulus,is defined to evaluate the difference in quality between the individual *** the discrete wavelet transform becomes trivial polyphase transform when setting the balance eccentric modulus at zero,we introduce a multiwavelet based scheme ***,a sufficient condition for balanced multiwavelet based multiple description coding is presented.

关键词： multiple description coding rate-distortion theory balance eccentric modulus balanced multiwavelet multifilter bank

Bursting of Morris-Lecar neuronal model with current-feedback control

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Science china(Technological sciences) 2009年第3期52卷 771-781页

作者： DUAN LiXia1, LU QiShao2 & CHENG DaiZhan3 1 College of Science, North china university of Technology, beijing 100144, china 2 School of Science, beijing university of Aeronautics and Astronautics, beijing 100191, china 3 Institute of Systems Science, chinese academy of sciences, beijing 100190, china College of Science North China University of Technology Beijing 100144 China School of Science Beijing University of Aeronautics and Astronautics Beijing 100191 China Institute of Systems Science Chinese Academy of Sciences Beijing 100190 China

The Morris-Lecar (ML) neuronal model with current-feedback control is considered as a typical fast-slow dynamical system to study the combined influences of the reversal potential VCa of Ca2+ and the feedback current I on the generation and transition of different bursting oscillations. Two-parameter bifurcation analysis of the fast subsystem is performed in the parameter (I, VCa)-plane at first. Three important codimension-2 bifurcation points and some codimension-1 bifurcation curves are obtained which enable one to determine the parameter regions for different types of bursting. Next, we further divide the control parameter (V0, VCa)-plane into five different bursting regions, namely, the "fold/fold" bursting region R1, the "fold/Hopf" bursting region R2, the "fold/homoclinic" bursting region R3, the "subHopf/homoclinic" bursting region R4 and the "subHopf/subHopf" bursting region R5, as well as a silence region R6. Codimension-1 and -2 bifurcations are responsible for explanation of transition mechanisms between different types of bursting. The results are instructive for further understanding the dynamical behavior and mechanisms of complex firing activities and information processing in biological nervous systems.

关键词： neuron bursting bifurcation fast-slow dynamics analysis codimension

On designated-weight Boolean functions with highest algebraic immunity

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Science china Mathematics 2010年第11期53卷 2847-2854页

作者： LIU MeiCheng1,3, DU YuSong2, PEI DingYi2 & LIN DongDai1 1The State Key Laboratory of Information Security, Institute of Software of chinese academy of sciences, beijing 100190, china 2College of Mathematics and Information sciences, Guangzhou university, Guangzhou 510006, china 3graduate university of chinese academy of sciences, beijing 100049, china 1. The State Key Laboratory of Information Security Institute of Software of Chinese Academy of Sciences Beijing 100190 China3. Graduate University of Chinese Academy of Sciences Beijing 100049 China2. College of Mathematics and Information Sciences Guangzhou University Guangzhou 510006 China

Algebraic immunity has been considered as one of cryptographically significant properties for Boolean functions. In this paper, we study ∑d-1 i=0 (ni)-weight Boolean functions with algebraic immunity achiev-ing the minimum of d and n - d + 1, which is highest for the functions. We present a simpler sufficient and necessary condition for these functions to achieve highest algebraic immunity. In addition, we prove that their algebraic degrees are not less than the maximum of d and n - d + 1, and for d = n1 +2 their nonlinearities equalthe minimum of ∑d-1 i=0 (ni) and ∑ d-1 i=0 (ni). Lastly, we identify two classes of such functions, one having algebraic degree of n or n-1.

关键词： cryptography Boolean function algebraic immunity algebraic degree nonlinearity

Chronology of Holocene lacustrine sediments in Co Ngoin, central Tibetan Plateau

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Science china Earth sciences 2006年第9期49卷 991-1001页

作者： WU Yanhong1, WANG Sumin1& HOU Xinhua1,3 1. Key Laboratory of Lake Sedimentation and Environment, Nanjing Institute of Geography and Limnology, chinese academy of sciences, Nanjing 210008, china 2. Institute of Tibetan Plateau Research, chinese academy of sciences, beijing 10085, china 3. graduate university of chinese academy of sciences, beijing 100039, china 1. Key Laboratory of Lake Sedimentation and Environment Nanjing Institute of Geography and Limnology Chinese Academy of Sciences Nanjing 210008 China 2. Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing 10085 China 3. graduate university of chinese academy of sciences Beijing 100039 China

Chronology is the basis for using lacustrine sediments to reconstruct the history of en-vironmental change. Radioactive-nuclides such as 14C, 210Pb and 137Cs dating are mainly used to establish the chronology for recent several ten thousand years. Because of being mixed with “dead carbon”, the measured 14C age is always older than the actual age which is recognized as “reservoir effect”. Cs is a kind of active metal element, and easy to migrate vertically in the sediment that leads to the error of the time marker. 210Pb dating should make sure to select CIC model or CRS model. On the Tibetan Plateau, most of the lakes are alkaline closed lake where Cs is more moveable in the sediment and the reservoir effect caused by “dead carbon” on 14C dating is stronger. Based on the analysis on results of 14C, 210Pb and 137Cs of the lacustrine sediments from Co Ngoin, central Tibetan Plateau, we use the simple regression method to re-calculate the 14C calendar ages, and establish the time sequence for cores CE-1 and CE-2 with result of 210Pb CRS model for the upper 35 cm and re-calculated 14C calendar age for sediments bellow 35 cm. Since 1400 cal. a BP, sedimentation inter-rupted for more than 1000 years. According to this time sequence, variations of environmental proxies confidently reflect the major climatic events in Holocene.

关键词： 14C, 210Pb and 137Cs, chronology, lacustrine sediments, climatic event, Co Ngoin, central Tibetan Plateau.

Analysis and application of automatic deformation monitoring data for buildings and structures of mining area

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中国有色金属学会会刊：英文版 2011年第S3期21卷 516-522页

作者： XIAO Jie1, 2, 3, ZHANG Jin4 1. Institute of Geodesy and Geophysics, chinese academy of sciences, Wuhan 430077, china 2. Key Laboratory of Dynamic Geodesy, Institute of Geodesy and Geophysics, chinese academy of sciences, Wuhan 430077, china 3. graduate School of chinese academy of sciences, beijing 100049, china 4. Department of Surveying and Mapping, Taiyuan university of Technology, Taiyuan 030024, china Taiyuan Univ Technol Dept Surveying & Mapping Taiyuan 030024 Peoples R China chinese Acad Sci Inst Geodesy & Geophys Key Lab Dynam Geodesy Wuhan 430077 Peoples R China chinese Acad Sci Grad Sch Beijing 100049 Peoples R China

The buildings and structures of mines were monitored automatically using modern surveying technology. Through the analysis of the monitoring data, the deformation characteristics were found out from three aspects containing points, lines and regions, which play an important role in understanding the stable state of buildings and structures. The stability and deformation of monitoring points were analysed, and time-series data of monitoring points were denoised with wavelet analysis and Kalman filtering, and exponent function and periodic function were used to get the ideal deformation trend model of monitoring points. Through calculating the monitoring data obtained, analyzing the deformation trend, and cognizing the deformation regularity, it can better service mine safety production and decision-making.

关键词： wavelet analysis Kalman filtering deformation monitoring data analysis mine