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2.02.The extra-strong warm winter event in North Asia and its accompanying anomalous atmospheric circulation

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chinese Science Bulletin 2003年第10期48卷 1031-1033页

作者： WANg Huijun LASg, Institute of Atmospheric Physics, chinese academy of sciences, beijing 10002.,{2. LASg Institute of Atmospheric Physics Chinese Academy of Science China

Features of an extra-strong warm winter event in North Asia in 2.02.and its accompanying anomalous atmospheric circulation were studied through diagnosis on the atmospheric reanalysis data set. Results show that the winter of 2.02.is of the warmest in the recent 54 years in North Asia, which was caused by both decadal scale and interannual scale variability. The interannual variability is proved to be as the main cause for the event, and it is related to the global scale atmospheric circulation anomalies, with the strongest of them in the Eastern Hemisphere and in the middle and high latitude region of the Southern Hemisphere.

关键词：大气环流亚洲北部高强度暖冬现象天气资料

Spectroscopic evidence for triplet excitation energy transfer among carotenoids in the LH2.complex from photosynthetic bacterium Rhodopseudomonas palustris

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Science china Chemistry 2004年第1期47卷 80-90页

作者： FENg Juan, WANg Qian, ZHANg Xujia, HUANg Youguo, Al Xicheng, ZHANg Xingkang & ZHANg JianpingState Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, chinese academy of sciences, beijing 100080,{2. National Laboratory of Biomacromolecules, Institute of Biophysics, chinese academy of sciences, beijing 100101,{2. State Key Laboratory for Structural Chemistry of Unstable and Stable Species Institute of Chemistry Chinese Academy of Sciences Beijing China National Laboratory of Biomacromolecules Institute of Biophysics Chinese Academy of Sciences Beijing China

The LH2.complex from Rhodopsudomonas (Rps.) palustris is unique in the heterogeneous carotenoid compositions. The dynamics of triplet excited state Carotenoids (3Car* has been investigated by means of sub-microsecond time-resolved absorption spectroscopy both at physiological temperature (2.5 K) and at cryogenic temperature (77K). Broad and asymmetric T n ←T 1 transient absorption was observed at room temperature following the photo-excitation of Car at 532.nm, which suggests the contribution from various carotenoid compositions having different numbers of conjugated C=C double bonds (Nc=c). The triplet absorption bands of different carotenoids, which superimposed at room temperature, could be clearly distinguished upon decreasing the temperature down to 77 K. At room temperature the shorter-wavelength side of the main Tn04T1 absorption band decayed rapidly to reach a spectral equilibration with a characteristic time constant of ∽1 μs, the same spectral dynamics, however, was not observed at 77 K. The aforementioned spectral dynamics can be explained in terms of the triplet-excitation transfer among heterogeneous carotenoid compositions. global spectral analysis was applied to the time-resolved spectra at room temperature, which revealed two spectral components peaked at 545 and 565 nm, and assignable to the Tn04 T1 absorption of Cars with Nc=c=11 and Nc=c=13, respectively. Surprisingly, the decay time constant of a shorter-conjugated Car, i.e. 0.72.?s (aerobic) and 1.36 ?s (anaerobic), is smaller than that of a longer-conjugated Car, i.e. 2.12.us (aerobic) and 3.75 ?s (anaerobic), which is contradictory to the general rule of carotenoids and relative polyenes. The results are explained in terms of triplet-excitation transfer among different types of Cars. It is postulated that two Cars with different conjugation lengths coexist in an α, β-subunit in the LH2.complex.

关键词： purple photosynthetic bacteria, carotenoid, excited-state, time-resolved spectroscopy.

Adaptive computation for convection dominated diffusion problems

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Science china Mathematics 2004年第Z1期47卷 22-31页

作者： CHEN Zhiming & Jl guanghuaLSEC, Institute of Computational Mathematics, academy of Mathematics and System sciences,{2., beijing 100080, china Institute of Computational Mathematics, academy of Mathematics and System sciences,{2., beijing 100080, china (email:ghji@***) LSEC Institute of Computational Mathematics Academy of Mathematics and System Sciences Chinese Academy of Sciences Beijing China Institute of Computational Mathematics Academy of Mathematics and System Sciences Chinese Academy of Sciences Beijing China

We derive sharp L∞(L1) a posteriori error estimate for the convection dominated diffusion equations of the formThe derived estimate is insensitive to the diffusion parameter ε→0. The problem is dis-cretized implicitly in time via the method of characteristics and in space via continuous piecewise linear finite elements. Numerical experiments are reported to show the competitive behavior of the proposed adaptive method.

关键词： a posteriori error estimator, characteristics, adaptive.

A shortest path algorithm for moving objects in spatial network databases

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Progress in Natural Science:Materials International 2008年第7期18卷 893-899页

作者： Xiaolan Yin a,b,*, Zhiming Ding c, Jing Li a a Technology Center of Software Engineering, Institute of Software, chinese academy of Science, P.O. Box 8718, {2. 100080, china b g.aduate University, chinese academy of sciences, {2. 100049, china c Technology Center of Basic Software, Institute of Software, chinese academy of sciences, {2. 100080, china Technology Center of Software Engineering Institute of Software Chinese Academy of Science P.O. Box 8718 Beijing 100080 China g.aduate University Chinese Academy of Sciences Beijing 100049 China Technology Center of Basic Software Institute of Software Chinese Academy of Sciences Beijing 100080 China

One of the most important kinds of queries in Spatial Network Databases (SNDB) to support location-based services (LBS) is the shortest path query. given an object in a network, e.g. a location of a car on a road network, and a set of objects of interests, e.g. hotels, gas station, and car, the shortest path query returns the shortest path from the query object to interested objects. The studies of shortest path query have two kinds of ways, online processing and preprocessing. The studies of preprocessing suppose that the interest objects are static. This paper proposes a shortest path algorithm with a set of index structures to support the situation of moving objects. This algorithm can transform a dynamic problem to a static problem. In this paper we focus on road networks. However, our algorithms do not use any domain specific information, and therefore can be applied to any network. This algorithm’s complexity is O(klog2.), and traditional Dijkstra’s complexity is O((i + k)2..

关键词： Moving object Spatial network databases Shortest path index Shortest path

A new method to prepare clean cuticular membrane from fossil leaves with thin and fragile cuticles

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Science china Earth sciences 2011年第2期54卷 223-227页

作者： WANg Li1,2.& LENg Qin1,3 1 State Key Laboratory of Palaeobiology and Stratigraphy,Nanjing Institute of geology and Palaeontology,chinese academy of {2.,Nanjing 2.0008,china 2.g.aduate school of chinese academy of sciences,beijing 100049,china 3 Department of Science and Technology,Bryant University,Smithfield RI 02.17,USA State Key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences Nanjing China g.aduate school of{2. Beijing China Department of Science and Technology Bryant University Smithfield USA

Leaf cuticle analysis has long been a powerful tool for fossil plant identification, systematics, and palaeoclimatological recon- struction. In recent decades the application of stomatal frequency data that are relied on precise calculation of stomata on plant fossil cuticles to reconstruct ancient atmospheric CO2.concentration made the preparation of cuticular membrane with sufficient size a critical technique in palaeoclimatological research. However, for plants with originally thin and fragile cuticles, e.g., most deciduous plants, conventional techniques sometimes fail to obtain cuticular membranes with sufficient size, or sometimes unable to recover any. This has largely hampered the usage of fossil cuticle analysis in palaeobotanical and palaeo- climatological research. Here, we describe a new method using clear nail polish as a medium to ＂strengthen＂ the originally thin and fragile cuticles prior to maceration procedures. We demonstrate the method by using middle Eocene Metasequoia fossils that were notorious for the difficulty of recovering large-sized clean cuticular membranes due to their thin and fragile nature. Metasequoia, with well-documented and widely-distributed fossil records since the Late Cretaceous and with a living repre- sentative, 114. glyptostroboides, as a comparative reference, bas been widely used as a model genus for the study of evolution of plants, palaeoclimatological reconstruction, and plant adaptation to climate changes. But its deciduous habit produces thin cuticles and makes the preparation of clean cuticular membranes a tedious process. The new method successfully allows us to recover its delicate cuticular membranes with sufficient sizes for SEM observation and stomatal frequency analysis.

关键词： fossil leaf cuticle Metasequoia new method thin and fragile cuticle SEM observation stomatal frequency CO2

EXPANSION OF STEP-TRANSITION OPERATOR OF MULTI-STEP METHOD AND ITS APPLICATIONS (Ⅱ)

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Journal of Computational Mathematics 2002年第2期20卷 461-478页

作者： Yi-fa Tang(State Key Laboratory of Scientific and Engineering Computing, ICMSEC, academy of Mathematics and System sciences,{2., P.O. Box 2.19, beijing 100080, china) 中科院数学与系统科学院 LSEC ICMSEC CAS 北京 100080

We give some formulae for calculation of the expansions for (1) composition of step-transition operators (STO) of any two difference schemes (DS) for ODE's, (2. inverse operator of STO of any DS, and (3) conjugate ope... 详细信息

关键词： Step-transition operator Expansion Composition Inverse operator Conjugate operator.

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Explicit formula of holomorphic automorphism group on complex homogeneous bounded domains

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Science china Mathematics 2006年第10期49卷 1392-1404页

作者： XU Yichao,CHEN Minru & MA Songya academy of Mathematics and Systems Science, chinese academy of sciences, {2. 100080, china College of Mathematics and Information sciences, Henan University, Kaifeng 475001, china academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing China College of Mathematics and Information sciences Henan University Kaifeng China

We known that the maximal connected holomorphic automorphism group Aut (D)(0) is a semi-direct product of the triangle group T(D) and the maximal connected isotropic subgroup Iso (D)(0) of a fixed point in the complex homogeneous bounded domain D and any complex homogeneous bounded domain is holomorphic isomorphic to a normal Siegel domain D(VN,F).In this paper, we give the explicit formula of any holomorphic automorphism in T(D(VN,F)) and Iso (D(VN, F))(0), where g(0) is the unit connected component of the Lie group g.

关键词： holomorphic automorphism group, homogeneous Siegel domain, normal Siegel domain, complex homogeneous bounded domain.

Numerical simulation of Richtmyer-Meshkov instability

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Science china Mathematics 2004年第z1期47卷 234-244页

作者： FU Dexun, MA Yanwen, ZHANg Linbo & TIAN BaolinState Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, chinese academy of sciences, beijing 100080,{2. State Key Laboratory of Scientific and Engineering Computing, Institute of Computational Mathematics, chinese academy of sciences, beijing 100080,{2. State Key Laboratory of Nonlinear Mechanics Institute of Mechanics Chinese Academy of Sciences Beijing China State Key Laboratory of Scientific and Engineering Computing Institute of Computational Mathematics Chinese Academy of Sciences Beijing China

The compressible Navier-Stokes equations discretized with a fourth order accurate compact finite difference scheme with group velocity control are used to simulate the Richtmyer-Meshkov (R-M) instability problem produced by cylindrical shock-cylindrical material interface with shock Mach number Ms=1.2.and density ratio 1:2. (interior density/outer density). Effect of shock refraction, reflection, interaction of the reflected shock with the material interface, and effect of initial perturbation modes on R-M instability are investigated numerically. It is noted that the shock refraction is a main physical mechanism of the initial phase changing of the material surface. The multiple interactions of the reflected shock from the origin with the interface and the R-M instability near the material interface are the reason for formation of the spike-bubble structures. Different viscosities lead to different spike-bubble structure characteristics. The vortex pairing phenomenon is found in the initial double mode simulation. The mode interaction is the main factor of small structures production near the interface.

关键词： R-M instability, direct numerical simulation, shock-interface interaction.

A new method of ionospheric-free hybrid differential positioning based on a double-antenna CAPS receiver

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Science china(Physics,Mechanics & Astronomy) 2009年第3期52卷 368-375页

作者： gUO JinYun1,2. HAN YanBen1 & CHANg XiaoTao3 1 National Astronomical Observatories, chinese academy of sciences, beijing 100012.{2. 2.College of geodesy and geomatics, Shandong University of Science and Technology, Qingdao 2.6510,{2. 3 chinese academy of Surveying and Mapping, beijing 100039,{2. National Astronomical Observatories Chinese Academy of Sciences Beijing China College of geodesy and geomatics Shandong University of Science and Technology Qingdao China chinese academy of Surveying and Mapping Beijing China

chinese Area Positioning System (CAPS) is a transmitted satellite navigation system moved by the chinese academy of sciences. Three basic modes of navigation and positioning with CAPS are given, and then a comparative analysis is made in this paper. In terms of the principle that the ionospheric delay is at an inverse ratio to the frequency square, a new ionospheric-free positioning method based on a double-antenna CAPS receiver is put forward. Then the hybrid differential observations and the solving equations and algorithms for one epoch and multi epochs are deduced according to the basic principle of the method. The method may remove the global errors in signal emission, propagation, transmission and receiving (e.g., ionospheric delay, hardware delay, and clock error). So it is very convenient for the single-epoch solution and multi-epoch navigation and positioning, and may efficiently improve the precision of real time CAPS navigation. Furthermore, the method can be used not only for the geometric orbit determination of CAPS gEO and IgSO satellites and the navigation and positioning, but also for the estimation of the tropospheric zenith delay, which is useful for the study of water vapor changes in the atmosphere. Polynomials are used in this method to express the tropospheric zenith delay and CAPS satellite orbits within the limited time interval, which reduces the num- ber of unknown parameters and thus speeds the computation.

关键词： chinese Area Positioning System (CAPS) ionospheric-free linear combination double-antenna receiver hybrid differential positioning method