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Forcing mechanism of the Pleistocene east Asian monsoon variations in a phase perspective

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Science china Earth sciences 2005年第10期48卷 1708-1717页

作者： TIAN Jun1,2. WANg Pinxian1, CHENg Xinrong1, WANg Rujian1 & SUN Xiangjun1,3 1. State Key Laboratory of Marine geology, Tongji University, Shanghai 2.0092. china 2. Institute of geology and geophysics, chinese academy of sciences, {2. 10002., china 3. Institute of Botany, chinese academy of sciences, {2. 100093, china Tongji University chinese academy of {2.

The deep sea records from the ODP Sites 1143 and 1144 in the northern and southern South china Sea (SCS), including foraminiferal δ 18O and δ 13C, Opal% and pollen percentage, reveal that the variations of the east Asian monsoon have been closely correlated with the variations of the Earth’s orbital parameters (eccentricity, obliquity and precession) and the global ice volume on orbital scale. All the monsoonal proxies show strong 100 ka, 41 ka and 2. ka cycles. Although g. ruber δ 13C of Site 1143 is coherent with the ETP (ETP= normalized (eccentricity + obliquity-precession) at eccentricity, obliquity and precession bands, most of the coherent relationship focuses on the precession band, and the other monsoonal proxies are coherent with the ETP only at the precession band, which indicate that precession dominates the Pleistocene tropical climate changes. The phase relationship of the monsoonal proxies with the foraminiferal δ 18O implies that the global ice volume changes have played a significant role in modulating the east Asian monsoon climate, at least dominating the winter monsoon. This forcing mechanism of the east Asian monsoon is apparently different from that of the Indian ocean mon-soon. The variations of the east Asian monsoon at the precession band, at least that of the winter monsoon, have been controlled not only by the sensible heating but also by the latent heating of the surface water in the South china Sea.

关键词： South china Sea, ODP, east Asian monsoon, orbital forcing, global ice volume.

Avoided crossings between non-radial modes in low mass RgB stars

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Research in Astronomy and Astrophysics 2012年第12期12卷 1655-1665页

作者： Jun-Jun guo1,2.3,Yan Li1,2.and Xiang-Jun Lai1,2.1 National Astronomical Observatories/Yunnan Observatory,chinese academy of {2., Kunming 650011,china 2.Key Laboratory for the Structure and Evolution of Celestial Objects,chinese academy of {2.,Kunming 650011,china 3 g.aduate University of chinese academy of sciences,beijing 100049,china National Astronomical Observatories/Yunnan Observatory Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences g.aduate University of chinese academy of sciences

Non-radial p modes and g modes appear simultaneously in red giant stars. Their frequencies have different variation rates,causing their frequencies to become close during stellar evolution so that avoided crossings *** separation between regions where acoustic waves and gravity waves propagate for l=1,2.and 3 is different,which results in the coupling efficiency also being *** present the results of numerical computations of the models we *** find that the two kinds of modes for l=2.and 3 need to be closer in frequency in order for a complete exchange to occur,compared to the case for modes with l=*** scaled oscillation frequencies also present better regularity with evolution than modes with l=1. In order to study the effect of the avoided crossings in detail,we set the mode which has the smallest mode inertia to be the p *** plot the two kinds of modes for l =1,2.and 3 in frequency and periodéchelle diagrams and find modes of l=2.and 3 fit the two relations better;they are more equally spaced in frequency and period than modes with l=*** careful observation of the two kinds oféchelle diagrams for l=2.and 3,we still find that some p modes shift a little from being equally spaced in frequency and some g modes,which are close to those p modes in period,shift a little from being equally spaced in ***,we study the relation between the deviation from period being equally spaced and the mode inertia of g modes for different *** g modes of l=1 with a period closer to the p mode have less inertia and the deviation is bigger in the periodéchelle *** deviation is also obvious. However g modes of l=2.and 3 shift a little or have almost no deviation from being equally spaced in period,even though some of them may have strong coupling and close mode inertia like in the p ***,we suggest a possible method for measuring period spacing of g modes precisely using mixed g modes with l=2.and 3 that have fewer observed mixed g m

关键词： stars:oscillations-stars:red giants

Design of secure operating systems with high security levels

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Science in china(Series F) 2007年第3期50卷 399-418页

作者： QINg SiHan1,2.& SHEN ChangXiang3 1 Institute of Software, chinese academy of sciences, beijing 100080,{2. 2.school of Software and Microelectronics, Peking University, beijing 102.00,{2. 3 Institute of Computing Technology, Navy, beijing 100841,{2. Institute of Software Chinese Academy of Sciences school of Software and Microelectronics Peking University Institute of Computing Technology

Numerous Internet security incidents have shown that support from secure operating systems is paramount to fighting threats posed by modern computing environments. Based on the requirements of the relevant national and international standards and criteria, in combination with our experience in the design and development of the ANSHENg v4.0 secure operating system with high security level （hereafter simply referred to as ANSHENg OS）, this paper addresses the following key issues in the design of secure operating systems with high security levels： security architecture, security policy models, and covert channel analysis. The design principles of security architecture and three basic security models： confidentiality, integrity, and privilege control models are discussed, respectively. Three novel security models and new security architecture are proposed. The prominent features of these proposals, as well as their applications to the ANSHENg OS, are elaborated. Cover channel analysis （CCA） is a well-known hard problem in the design of secure operating systems with high security levels since to date it lacks a sound theoretical basis and systematic analysis approach. In order to resolve the fundamental difficulties of CCA, we have set up a sound theoretical basis for completeness of covert channel identification and have proposed a unified framework for covert channel identification and an efficient backward tracking search method. The successful application of our new proposals to the ANSHENg OS has shown that it can help ease and speedup the entire CCA process.

关键词： secure operating systems with high security levels architecture security model covert channel analysis

Occurrences of Permian radiolarians in central and eastern Nei Mongol(Inner Mongolia) and their geological significance to the Northern china Orogen

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chinese Science Bulletin 2004年第24期49卷 2613-2619页

作者： SHANg Qinghua Nanjing Institute of geology and Paleontology,chinese academy of {2.,Nanjing 2.0008,china Institute of Vertebrate Paleontology and Paleoanthropology,chinese academy of {2.,beijing 100044,china Nanjing Institute of geology and Paleontology Chinese Academy of Sciences Nanjing 210008 China

The Zhesi (Jisu) Formation of the Middle Per- mian in Nei Mongol (Inner Mongolia) was commonly con- sidered to be a shallow marine sequence. Here I report the radiolarians found in the argillite bed of that formation in Zhesi and Xilinhot areas. This fact indicates a deep marine sedimentary facies persisted during the Middle Permian, and suggests that the ocean between the North china Block and Siberian Craton was not closed until the Late guadalupian. The suture of this two blocks is probably extends along the Linxi ophiolite belt, south of the Hegenshan ophiolite belt.

关键词：造山带地质意义内蒙古放射虫二叠纪

Modeling the impact of Australian Plate drift on Southern Hemisphere climate and environment

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chinese Science Bulletin 2005年第14期50卷 1495-1502页

作者： ZHOU Botao1,5, ZHAO Ping2. JIAN Zhimin3 & HE Jinhai4 1. Nansen-Zhu International Research Center, Institute of Atmospheric Physics, chinese academy of sciences, beijing 10002.,{2. 2. Institute of Climate and Environment, chinese academy of Meteoro- logical sciences, beijing 100081,{2. 3. Laboratory of Marine geology, Tongji University, Shanghai 2.0092.{2. 4. Department of Atmospheric sciences, Nanjing Institute of Meteorol- ogy, Nanjing 2.0044,{2. 5. g.aduate {12. of the chinese academy of sciences, beijing 100039,{2. Nansen-Zhu International Research Center Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China g.aduate school of the{2. Beijing 100039 China Institute of Climate and Environment Chinese Academy of Meteorological Sciences Beijing 100081 China Laboratory of Marine geology Tongji University Shanghai 200092 China Department of Atmospheric sciences Nanjing Institute of Meteorology Nanjing 210044 China

Using a global atmosphere-ocean coupled model with the present-day and 14 MaB.P. oceanic topogra- phy respectively, two experiments are implemented to inves- tigate the effect of different locations of Australian Plate on the atmospheric circulation in middle-high latitudes of the Southern Hemisphere. The results show that when Austra- lian Plate lay south at 14 MaB.P., both anticyclone circula- tions in the subtropical oceans and cyclone circulation around 60°-70°S are strengthened. Subtropical highs and circumpolar low pressure appear stronger, which results in much stronger Antarctic Oscillation and shorter period of Antarctic Oscillation Index (AOI) at 14 MaB.P. The rainfall and the surface air temperature also change correspondingly. The precipitation decreases around 40°S and increases around 60°-70°S, and the surface air temperature rises in high latitudes of the South Pacific and descends over the Weddell Sea and its north side. Besides, due to the changes of the temperatures and winds, Antarctic sea ice coverage also changes with its increasing in the Ross Sea and its west re- gions and decreasing in the Weddell Sea.

关键词：半球气候地球环球澳大利亚漂流物海洋地形学

Simulation of the future change of East Asian monsoon climate using the IPCC SRES A2.and B2.scenarios

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chinese Science Bulletin 2003年第10期48卷 1024-1030页

作者： BUEH Cholaw LASg, Institute of Atmospheric Physics, chinese academy of sciences, beijing 10002.,{2. LASg Institute of Atmospheric Physics Chinese Academy of Sciences China

In this paper, we applied the newest emission scenarios of the sulfur and greenhouse gases, i.e. Intergovernmental Panel on Climate Change (IPCC) Special Report on Emission Scenarios (SRES) A2.and B2.scenarios, to investigating the change of the East Asian climate in the last three decades of the 2.st century with an atmosphere-ocean coupled general circulation model. The global warming enlarges the land-sea thermal contrast and, hence, enhances (reduces) the East Asian summer (winter) monsoon circulation. The precipitation from the Yangtze and Huaihe river valley to North china increases significantly. In particular, the strong rainfall increase over North china implies that the East Asian rainy area would expand northward. In addition, from the southeastern coastal area to North china, the rainfall would increase significantly in September, implying that the rainy period of the East Asian monsoon would be prolonged about one month. In July, August and September, the interannual variability of the precipitation enhances evidently over North china, meaning a risk of flooding in the future.

关键词：模拟亚洲东方季风气侯变化大气循环模型

Comparative analysis of temperature and CO2.fluxes for winter wheat in Tibetan Plain and North china Plain using the EMD method

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Progress in Natural Science:Materials International 2006年第10期16卷 1066-1071页

作者： JIANg Zhaoyang, YU Qiang, LEI Shuhe, WANg Tianduo, SUN Xiaomin and ZHANg Renhua ( chinese academy of Meteorological Science, {2. 100081, china Institute of geographic sciences and Natural Resources Research, chinese academy of sciences, {2. 100101, china Mathematics Department, Ocean University of china, Qingdao 2.6071, china Shanghai Institute of Plant Physiology and Ecology, chinese academy of sciences, Shanghai 2.0032. china) chinese academy of Meteorological Science Beijing 100081 China Institute of geographic sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China Mathematics Department Ocean University of China Qingdao 266071 China Shanghai Institute of Plant Physiology and Ecology Chinese Academy of Sciences Shanghai 200032 China

Comparative study of spectral properties of temperature and CO2.fluxes measured by eddy covariance method at Yucheng (36°57'N, 116°36'E, 2. m a.s.l., in the North china Plain) and at Lhasa (2.°41'N, 91°2.'E, 3688 m a.s. 1., on the Tibetan Plateau) is described using the empirical mode decomposition (EMD) method. The main results are: (1) The intrinsic oscillation modes or intrinsic mode functions (IMFs) were extracted from data of temperature ( T) and CO2.fluxes (F) measured at Yucheng ( T1 and F1) and Lhasa ( T2.and F2. . (2. Hilbert transform was applied to these IMF components, then the Hubert-Huang spectra and the marginal spectra of these data were obtained. (3) Comparison of temperature and CO2.fluxes in North china Plain and on Tibetan Plain illustrated that the characteristic frequencies corresponding to T1, F1, T2.and F2.are 0.05 Hz, 0.03 Hz, 0.014 Hz and 0.005 Hz, respectively.

关键词： empirical mode decomposition (EMD) intrinsic mode function (IMF) flux Hilbert transform wheat Tibet.

Responses of soil respiration in non-growing seasons to environmental factors in a maize agroecosystem,Northeast china

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chinese Science Bulletin 2010年第24期55卷 2723-2730页

作者： LI RongPing1,2.3, ZHOU guangSheng1,4 & WANg Yu1,3 1 State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, chinese academy of sciences, beijing 100093,{2. 2.Institute of Atmospheric Environment,{2. Meteorological Administration, Shenyang 110016,{2. 3 g.aduate University of chinese academy of sciences, beijing 100049,{2. 4 chinese academy of Meteorological sciences, beijing 100081,{2. State Key Laboratory of Vegetation and Environmental Change Institute of Botany Chinese Academy of Sciences Beijing 100093 China Institute of Atmospheric Environment China Meteorological Administration Shenyang 110016 China g.aduate University of chinese academy of sciences Beijing 100049 China chinese academy of Meteorological {2. Beijing 100081 China

Based on continuous three-year measurements (from 2.04 to 2.07) of eddy covariance and related environmental factors, environmental controls on variation in soil respiration (Rs) during non-growing season were explored in a maize agroecosystem in Northeast china. Our results indicated that during non-growing seasons, daily Rs was 1.08-4.08 g CO2.m-2.d-1, and the lowest occurred in late November. The average Rs of non-growing season was 456.06 ± 2..01 g CO2.m-2. accounting for 11% of the gross primary production (gPP) of the growing season. Additionally, at monthly scale, the lowest value of Rs appeared in January or February. From the beginning to the end of non-growing season, daily Rs tended to decrease first, and then increase to the highest. There was a significant quadratic curve relationship between Rs and soil temperature at 10 cm depth when soil temperature was more than 0°C (Pg ratio of 38%-70%. When soil water content was more than 0.1 m3 m-3, soil moisture at 10 cm depth was significantly parabolically correlated with Rs (Pg the rate of 18%-60%. Based on all the data of soil temperature of more than 0°C, a better model for Rs was established by coupling soil temperature and moisture, which could explain the rate of up to 53%-79%. Meanwhile, the standard error of regression estimation between the values of prediction and observation for Rs could reach 2.7%-11.8%. Rs in non-growing season can account for 2..4% of Rs in growing season, indicating that it plays a critical role in assessing the carbon budget in maize agroecosystem, Northeast china.

关键词：中国东北地区农田生态系统生长季节土壤呼吸环境因素玉米土壤含水量反应

Hyperbolic geometry with geometric algebra

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chinese Science Bulletin 1997年第3期42卷 262-263页

作者： LI Hong boInstitute of Systems Science, chinese academy of sciences, beijing 100080,{2. Institute of Systems Science Chinese Academy of Sciences Beijing China

WE use the geometric algebra in refs. [1, 2. to study hyperbolic geometry. The n-dimensional hyperbolic space Hn is taken to be the unit sphere of g1 (I-n,1) with antipodal points identified. We study typically H2./sup>: the dualities between generalized point and generalized line, between generalized triangle and imaginary triangle; convex generalized triangles; Lorentz transformations; generalized circles and double-cycles, etc. Below we list some of the results.

关键词： line Hyperbolic geometry with geometric algebra