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The variation in the magnetic fluctuation anisotropy across the front boundaries of magnetic clouds and its geomagnetic response

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Chinese Science Bulletin 2002年第10期47卷 863-867页

作者： LIU Rui & WEI FengsiDepartment of Geophysics, Peking University, beijing 100871, china Lab for space Weather, Center for space Science and Applied Research, Chinese academy of Sciences, beijing 100080, china Department of Geophysics Peking University Beijing China Lab for space Weather Center for Space Science and Applied Research Chinese Academy of Sciences Beijing China

A statistical study of magnetic fluctuations near the front boundaries of magnetic clouds is approached with the method of Minimum Variance Analysis, based on the data of ImpS and Wind spacecraft. New discoveries are that (1) fluctuation anisotropy tends to increase across the front boundaries of magnetic clouds; (2) there is a good correlation between the fluctuation anisotropy and the geomagnetic activity indices; and (3) in some cases, although there is southward field component immediately after the front boundary, Kp index descends (or Dst index ascends) with a corresponding decrease of the fluctuation anisotropy; in other cases with no distinct southward field component, Kp index ascends (or Dst index descends) with a corresponding increase of the fluctuation anisotropy. Thus we suggest that the fluctuation anisotropy might be a useful indicator in diagnosing the magnetic activities of magnetic clouds.

关键词： front boundary of magnetic clouds geomagnetic activity fluctuation anisotropy.

Relative position determination of a lunar rover using high-accuracy multi-frequency same-beam VLBI

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Science china(Physics,Mechanics & Astronomy) 2010年第3期53卷 571-578页

作者： LIU QingHui1, CHEN Ming1, XIONG WeiMing2, QIAN ZhiHan1, LI JinLing1, HAO WangHong1,4, WANG GuangLi1, ZHENG WeiMin1, GUAN Di3, ZHU RenJie1, WANG WeiHua1, ZHANG XiuZhong1, JIANG DongRong1, SHU FengChun1, PING JinSong1 & HONG XiaoYu11 Shanghai Astronomical Observatory, Chinese academy of Sciences, Shanghai 200030, china 2 Center for space Science and Applied Research, Chinese academy of Sciences, beijing 100190, china 3 Lunar Explorer Engineering General Department, Chinese academy of Sciences, beijing 100012, china 4 beijing Institute of Tracking and Telecommunications technology, beijing 100094, china Shanghai Astronomical Observatory Chinese Academy of Sciences Center for space Science and Applied Research Chinese Academy of Sciences

Multi-frequency same-beam VLBI means that two explorers with a small separation angle are simultaneously observed with the main beam of receiving antennas. In the same-beam VLBI, the differential phase delay between two explorers and two receiving telescopes can be obtained with a small error of several picoseconds. The differential phase delay, as the observable of the same-beam VLBI, gives the separation angular information of the two explorers in the celestial sphere. The two-dimensional relative position on the plane-of-sky can thus be precisely determined with an error of less than 1 m for a distance of 3.8×105 km far away from the earth, by using the differential phase delay obtained with the four Chinese VLBI stations. The relative position of a lunar rover on the lunar surface can be determined with an error of 10 m by using the differential phase delay data and the range data for the lander when the lunar topography near the rover and the lander can be determined with an error of 10 m.

关键词： same-beam VLBI differential phase delay relative position determination lunar rover

Maximal effective baseline for polarimetric interferometric SAR forest height estimation

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Science china(Information Sciences) 2012年第4期55卷 867-876页

作者： ZHOU YongSheng 1,2,3,HONG Wen 1,2,WANG YanPing 1,2 & WU YiRong 1,2 1 National Key Laboratory of Science &technology on Microwave Imaging,beijing 100190,china 2 Institute of Electronics,Chinese academy of Sciences,beijing 100190,china 3 academy of Opto-Electronics,Chinese academy of Sciences,beijing 100094.china National Key Laboratory of Science & technology on Microwave Imaging Beijing China Institute of Electronics Chinese Academy of Sciences Beijing China academy of Opto-Electronics Chinese Academy of Sciences Beijing China

The concepts of critical baseline and maximal effective baseline have been defined for interferometric SAR (InSAR) DEM application based on the spatial decorrelation (which is a function of baseline).This paper puts forward these two concepts to polarimetric interferometric SAR (Pol-InSAR) forest height estimation *** application makes use of volume decorrelation,which is also a function of *** both the spatial decorrelation and volume decorrelation are considered to determine Pol-InSAR critical and maximal effective *** various decorrelation effects are *** the calculation formula of Pol-InSAR maximal effective baseline are presented and compared to that of *** validation,RVoG-based and PolSARpro-based simulation data and DLR ESAR data are *** concept of Pol-InSAR maximal effective baseline is of practical significance in selection of Pol-InSAR image pairs as well as in the design of further Pol-InSAR systems.

关键词： Pol-InSAR maximal baseline forest height estimation

Damage from Particle Impact for Structural Ceramics

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Journal of Materials Science & technology 1994年第1期10卷 54-58页

作者： Zhongzhe JIN and Yiwang BAO(china Building Materials academy, beijing, 100024, china) china Building Materials Acad Beijing China

In this study, the relationship between the maximum impact force and velocity of partjcle has been derived on the basis of elastic theory and energy principle. Critical impact force and critical speed which cause initial damage is anaIVsed and its analytical expression is presented. The impact force for six dlfferent materials was measu red at the same condition to investigate the v8riation of impact pararneter with material properties. The authors provide a simple test method and experimental de vice to imitate the impact of moving particle, A series of experiments on ceramics and gIass were car ried out to study the dependence of residual strength on the impulse.

关键词： Damage from Particle Impact for Structural Ceramics

The deep thermal characteristic of continental margin of the northern South china Sea

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Chinese Science Bulletin 2000年第18期45卷 1717-1722页

作者： ZHANG Jian & WANG Jiyang1. Graduate School, University of Science and technology of china, Chinese academy of Sciences, beijing 100039, china 2. Institute of Geology, Chinese academy of Sciences, beijing 100029, china Graduate School University of Science and Technology of China Chinese Academy of Sciences Beijing China Institute of Geology Chinese Academy of Sciences Beijing China

Heat flow plays an important role in the study ot thermal structure and thermal evolutionof continental margin of the northern South china Sea. The analysis of heat flow value shows that margin heat flow in the northern South china Sea is relatively high setting, but the percentage of crustal heat flow is lower than 35% in terrestrial heat flow. The terrestrial heat flow exhibited a current of rise from the Northern Continental Margin to the Southern Central Basin. However, the proportion of crustal heat flow in terrestrial heat flow slowly dropped down in the same direction. It is suggested that the main factor causing high heat flow setting is the moving up of hot material from asthenosphere.

关键词： margin of northern South china Sea terrestrial heat flow thermal structures.

ON THE CENTRAL RELAXING SCHEME Ⅱ: SYSTEMS OF HYPERBOLIC CONSERVATION LAWS

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Journal of Computational Mathematics 2001年第6期19卷 571-582页

作者： Hua-zhong Tang (School of Mathematical Sciences, Peking University, beijing 100871, china) (LSEC,ICMSEC academy of Mathematics and Systems Sciences, Chinese academy of Sciences, beijing 100080, china) School of Mathematical Sciences Peking University Beijing 100871 China

This paper continues to study the central relaxing schemes for system of hyperbolic conservation laws, based on the local relaxation approximation. Two classes of relaxing systems with stiff source term are introduced to approximate system of conservation laws in curvilinear coordinates. Based on them, the semi-implicit relaxing schemes are con- structed as in [6, 12] without using any linear or nonlinear Riemann solvers. Numerical experiments for one-dimensional and two-dimensional problems are presented to demon- strate the performance and resolution of the current schemes.

关键词： Hyperbolic conservation laws The relaxing system The central relaxing schemes The Euler equations.

Two possible mechanisms for vortex self-organization

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Science china Earth Sciences 2006年第2期49卷 202-211页

作者： LUO Zhexian2, ZHOU Xiuji1 & GAO Shouting3 1. Chinese academy of Meteorological Sciences, beijing 100081, china 2. Department of space Information Science, Nanjing University of Information Science and technology, Nanjing 210044, china 3. Institute of Atmospheric Physics, Chinese academy of Sciences, beijing 100029, china Department of Environmental Science Nanjing University of Information Science and Technology Nanjing China Chinese academy of Meteorological Sciences Beijing China Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China

The vortex self-organization is investigated in this paper by four groups of numerical experiments within the framework of quasi-geostrophic model, and based on the experimental results two types of possible mechanisms for vortex self-organization are suggested. The meso-scale to-pography may enable separated vortices to merge into a larger scale vortex; and the interaction of meso-γ and meso-β scale systems may make separated vortices to self organize a typhoon-like vor-tex circulation.

关键词： vortex, self-organization, meso-scale topography, interaction of different scales.

Comment on “Evolution model of the earth's limited expanding” from comparative planetology

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Chinese Science Bulletin 2001年第17期46卷 1495-1496页

作者： SHI YaolinGraduate School, University of Science and technology of china, Chinese academy of Sciences, beijing 100039, china Graduate School University of Science and Technology of China Chinese Academy of Sciences Beijing China

In the article 'Evolution Model of the Earth’s Limited Expanding' published in Volume 45 Number (4) of Chinese Science Bulletin[1], the author suggests that the earth expands according to a law R(t) = R0+A(1 -exp(β(t-ts))) (remark: this formula was mistakenly printed as R(t) = R0 + Aexp(β(t-ts)) in the and formula (12) of the text of ref. [1]). According to ref. [1], the earth was formed 4.6 billion years ago. After 0.3 billion years from its birth (ts), it started expansion from an initial radius R0 of 4651 km, and may reach a final maximum radius of R0+A = 6511 km. In the 4.6 billion years history, the radius of the earch has increased by 1720 km, or the density decreased from 14200 km/m3 (2.57 times the present density) to 5520 kg/m3 within the latest 4.3 billion years.

关键词： from comparative planetology Evolution model of the earth’s limited expanding

The Development and Application of Combined Thermoregulatory Mathematical Models

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Journal of Systems Engineering and Electronics 1991年第2期2卷 55-64页

作者： Gu Dingliang and Pang ChengInstitute of space Medico-Engineering, beijing 100094, china Institute of space Medico-Engineering Beijing 100094 China

Thermoregulatory mathematical models have being developed for more than half a century and obtained more and more wide application. Among them, the 'engineering-physiological' thermal models, which correlated closely to the man-machine-environment system, are the ones that developed most rapidly and have been widely accepted by thermal physiologists and environmental control *** paper attempts to outline briefly the development and application of such kind of thermal models, discusses how to further develop and apply various combined thermal models in practice, and puts forward four respects of suggestions for establishment and modification of combined thermal models of man-clothing-cabin environment.

关键词： Thermoregulatory mathematical model Man-clothing-cabin environment system.