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Latest progress on interactions between VLF/ELF waves and energetic electrons in the inner magnetosphere

science china earth sciences 2010年第3期53卷 317-326页

作者： XIAO FuLiang1,2, ZONG QiuGang3, SU ZhenPeng4, TIAN Tian3 & ZHENG HuiNan4 1 school of Physics and Electronic sciences, Changsha university of science and technology, Changsha 410004, china 2 State key laboratory of space Weather, Chinese Academy of sciences, Beijing 100190, china 3 Institute of space Physics and Applied technology, Peking university, Beijing 100871, china 4 cas key lab for basic plasma science, school of earth and space sciences, university of science and technology of china, hefei 230026, china 1. school of Physics and Electronic sciences Changsha University of Science and Technology Changsha 410004 China2. State Key Laboratory of Space Weather Chinese Academy of Sciences Beijing 100190 China3. Institute of Space Physics and Applied Technology Peking University Beijing 100871 China4. CAS Key Lab for Basic Plasma Science School of Earth and Space Sciences University of Science and Technology of China Hefei 230026 China

Interactions between very/extremely low frequency (VLF/ELF) waves and energetic electrons play a fundamental role in dynamics occurring in the inner magnetosphere. Here, we briefly discuss global properties of VLF/ELF waves, along with the variability of the electron radiation belts associated with wave-particle interactions and radial diffusion. We provide cases of electron loss and acceleration as a result of wave-particle interactions primarily due to such waves, and particularly some preliminary results of 3D evolution of phase space density from our currently developing 3D code. We comment on the existing mechanisms responsible for acceleration and loss, and identify several critical issues that need to be addressed. We review latest progress and suggest open questions for future investigation.

关键词： wave-particle interaction VLF/ELF waves energetic electrons acceleration and loss inner magnetosphere

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Sm-Nd and zircon SHRIMP U-Pb dating of Huilanshan mafic granulite in the Dabie Mountains and its zircon trace element geochemistry

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science china earth sciences 2005年第12期48卷 2081-2091页

作者： HOU Zhenhui1, LI Shuguang1, CHEN Nengsong2, LI Qiuli1 & LIU Xiaoming3 1. school of earth and space sciences, university of science and technology of china, hefei 230026, china 2. The key laboratory of Continental Dynamics of the Ministry of Education, Northwest university, Xi’an 710069, china 3. Faculty of earth sciences, china university of Geosciences, Wuhan 430074, china 1. school of earth and space sciences University of Science and Technology of China 230026 Hefei China 2. The key laboratory of Continental Dynamics of the Ministry of Education Northwest University 710069 Xi’an China 3. Faculty of earth sciences China University of Geosciences 430074 Wuhan China

The mafic granulites from Huilanshan are outcropped on the center of the Luotian dome in the northern Dabie Mountains. The Sm-Nd isochron defined by granulite-facies meta-morphic minerals (garnet + clinopyroxene + hypersthene) yields an age of 136 ± 18 Ma indicating the early Cretaceous granulite-facies metamorphism. The cathodoluminescence (CL) images of zircons from the granulite show clearly core-mantle-rim structures. The zircon cores are charac-terized by typical oscillatory zoning and highly HREE enriched patterns, which suggests their magma origin. Some zircon cores among them with little Pb loss give SHRIMP U-Pb ages rang-ing from 753 to 780 Ma, which suggests that the protolith of Huilanshan granulite is Neopro-terozoic mafic rocks. The zircon mantles usually cut across the oscillatory zone of the zircon cores have 3―10 times lower REE, Th, U, Y, Nb and Ta contents than the igneous zircon cores but have high common Pb contents. These characteristics suggest that they were formed by hydrothermal alteration of the igneous zircons. The part of zircon mantles with little Pb loss give a similar SHRIMP U-Pb age (716―780 Ma) to the igneous zircon cores, which implies that the hydrothermal events occurred closely to the magmatic emplacement. In view of the strong early Cretaceous magmatism in the Luotian dome, consequently, the Huilanshan mafic granulite was formed by heating of the Neoproterozoic mafic rocks in mid-low crust, which caused the granu-lite-facies metamorphism underneath the Dabie Mountains. The similarity between the granulite metamorphic age (136 ± 18 Ma) defined by Sm-Nd isochron and K-Ar age of 123―127 Ma given by amphible from the gneiss in Luotian dome suggests a rapid uplifting of the Luotian dome, which may result in further exhumation of the ultrahigh pressure metamorphic rocks in the Dabie Mountains.

关键词： Dabie orogen, granulite, zircon U-Pb ages, Sm-Nd age.

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The structural analysis of fuzzy measures

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science china(Information sciences) 2011年第1期54卷 38-50页

作者： ZHANG Ling1,ZHANG Bo2 & ZHANG YanPing1 1 Computer science College,Anhui university,hefei 230039,china 2State key lab of Intelligent technology & Systems Tsinghua National lab for Information science & technology Information science & technology College,Computer science & technology,Tsinghua university,Beijing 100084,china 1. Computer science College Anhui University Hefei 230039 China2. State Key Lab of Intelligent Technology & Systems Tsinghua National lab for Information science & technology Information science & technology College Computer Science & Technology Tsinghua University Beijing 100084 China

From quotient space based granular computing theory we explore the fuzzy measures of fuzzy sets. Based on the structural analysis of fuzzy sets,we present an"isotropism"*** this assumption we achieved the following insights:(1)the uniqueness of a fuzzy measure being isotropic on a finite complete semi-ordered set;(2)the necessary and suffcient condition of the isomorphism for fuzzy measure functions in fuzzy mathematics;(3)the necessary and suffcient condition that fuzzy measures have fuzzy and granular monotonicity;(4)under a certain assumption,the analytic expression for fuzzy *** results clarify the relationship between fuzzy measures and granular computing,reveal the essence of fuzzy measures,and provide a simple way of constructing fuzzy measures.

关键词： quotient space fuzzy set fuzzy measure rough set structural analysis

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Multi-isotopic system geochronology of low temperature eclogite from Huangzhen,Southern Dabie Terrain

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science china earth sciences 2004年第10期47卷 931-942页

作者： CHEN Daogong1, E. Deloule2, CHENG Hao1, XIA Qunke1 & WU Yuanbao1 1. school of earth and space sciences, university of science and technology of china, hefei 230026, china 2. CRPG-CNRS Nancy, 54501, France 1. school of earth and space sciences University of Science and Technology of China 230026 Hefei China 2. CRPG-CNRS 54501 Nancy France

Zircon U-Pb thermal ionization mass-spectrometer (TIMS) and secondary ion mass-spectrometer (SIMS) dating, mica and amphibole 40Ar-39Ar dating and mineral Sm-Nd isotopic compositions of Huangzhen low temperature eclogite and country granitic gneiss are carried out. The zircon U-Pb weighted average SIMS age is (231.6?9.7) Ma for one eclogite. The mica 40Ar-39Ar isochron age is (232.6?2.1) Ma and the lowest plateau age is (221.7?2.4) Ma from same sample. U-Pb TIMS concordant ages from other eclogite zircons are from (221.3?1.4) Ma to (222.5?2.3) Ma. U-Pb SIMS low intercept age from country granitic gneiss is (221?35) Ma. The retrograde amphibole 40Ar-39Ar isochron age is (205.9?1.0) Ma. Except for mica, which may contain excess 40Ar, all the ages represent peak and retrograde metamorphism of low temperature eclogites. It is indicated that the Huangzhen low temperature eclogites differ from Xiongdian low temperature eclogites of north of the Northern Dabie Terrain in metamorphic ages. Huangzhen low temperature eclogites share one coherent HP-UHP terrain with high temperature eclogites from Southern Dabie Terrain and they may have differences in subduction depth and cooling rates during exhumation.

关键词： low temperature eclogite, multi-isotopic dating, HP-UHP metamorphism, Dabieshan.

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Discovery and analysis of ultra-micro grinding grain texture in slipping lamellae of ductile-brittle zone

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science china earth sciences 2004年第3期47卷 265-271页

作者： GE Heping1, SUN Yan1, LU Xiancai1, ZHU Wenbin1, GUO Jichun1, LIU Deliang2 & Chi-yuen Wang3 1. Department of earth sciences, Nanjing university, State key laboratory of Mineral Deposit, Nanjing 210093, china 2. Department of earth and space sciences, university of science and technology of china, hefei 230026, china 3. Department of Geology and Geophysics, university of California, Berkeley, CA 94720, USA Nanjing Univ Dept Earth Sci State Key Lab Mineral Deposit Nanjing 210093 Peoples R China Univ Sci & Technol china Dept Earth & Space Sci Hefei 230026 Peoples R China Univ Calif Berkeley Dept Geol & Geophys Berkeley CA 94720 USA

Based on the observation of the deep bore cores sampled from the State of Cali-fornia, USA, preferred arranged particulate concentration belts were found in the ultra-slipping lamellae. And the same phenomenon was found again later in the bore cores from the petroleum basin in the Northern Shaanxi Province. It may be the product of the dynamic processes involv-ing tumbling, grinding and compresso-shearing functions, so the spherical particulates with ul-tra-size of nm and mm are called grinding grain. The formation of the grinding grains is related with the ductile-brittle deformation, the lateral pressure of the slipping, and the very low grade of dynamic metamorphism of the rocks. Based on the systematic analysis, it is indicated that some elements like Nb and Ta are enriched in the grinding grains in the granitic rocks because of the chemical differentiation, and that the slipping lamellae bearing grinding grains in mudstone with smear efficiency prove a perfect seal for oil and gas reservoirs. Meanwhile, the paper provides bases for the studies on the fast stick-slip movement and shear paradigm.

关键词： slipping lamellae, grinding grain texture, ductile-brittle deformation, smear efficiency.

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Numerical study of the auroral particle transport in the polar upper atmosphere

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science china(Technological sciences) 2008年第10期51卷 1759-1771页

作者： CAI HongTao1,2, MA ShuYing1,2 & PU ZuYin3 1 school of Electronic Information, Wuhan university, Wuhan 430079, china 2 key laboratory of Geospace Environment and Geodesy, Ministry of Education of PRC, Wuhan 430079, china 3 school of earth and space sciences, Peking university, Beijing 100871, china 1. school of Electronic Information Wuhan University Wuhan 430079 China 2. key laboratory of Geospace Environment and Geodesy Ministry of Education of PRC Wuhan 430079 China 3. school of earth and space sciences Peking University Beijing 100871 China

Starting from the Boltzmann equation and with some reasonable assumptions, a one-dimensional transport equation of charged energetic particles is derived by taking account of major interactions with neutral species in the upper atmosphere, including the processes of elastic scattering, the excitation, the ionization and the secondary electron production. The transport equation is numerically solved, for a simplified atmosphere consisting only of nitrogen molecules (N2), to obtain the variations of incident electron fluxes as a function of altitude, energy and pitch angle. The model results can describe fairly the transport characteristics of pre-cipitating auroral electron spectra in the polar upper atmosphere; meanwhile the N2 ionization rates calculated from the modeled differential flux spectra also exhibit good agreements with existing empirical models in terms of several key parameters. Taking the energy flux spectra of precipitating electrons observed by FAST satellite flying over EISCAT site on May 15, 1997 as model inputs, the model-calculated ionization rate profile of neutral atmosphere consists reasonably with that recon-structed from electron density measurements by the radar.

关键词： aurora particle precipitation polar upper atmosphere electron transport equation numerical simulation

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Enhancement of Solar Energetic Particles During A Shock Propagating through A Preceding Magnetic Cloud

Enhancement of Solar Energetic Particles During A Shock Prop...

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第十二届全国日地空间物理学术讨论会

作者： Chenglong Shen~1 Yuming Wang~1 Pinzhong Ye~1 Shui Wang~1 (1 cas key laboratory of basic plasma Physics,school of earth & space sciences.,university of science & technology of china,hefei,Anhui 230026,P.R.china

＜正＞Five cases of magnetic clouds （MCs） overtaken by shocks are reported by investigating the magnetic field and solar wind plasma data observed by ACE *** integral proton flux data observed by GOES spacecraft are...

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Monitoring of rice crop using ENVISAT ASAR data

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science china earth sciences 2006年第7期49卷 755-763页

作者： DONG Yanfang1, 2, SUN Guoqing1,3 & PANG Yong4 1. State key laboratory of Remote Sensing science, Institute of Remote Sensing Applications, Chinese Academy of sciences, Beijing 100101, china 2. Graduate university of Chinese Academy of sciences, Beijing 100039, china 3. Department of Geography, university of Maryland, College Park, MD 20742, USA 4. Forest Remote Sensing lab, Research Institute of Forest Resource and Information technology, Chinese Academy of For-estry, Beijing 100091, china 1. State key laboratory of Remote Sensing science Institute of Remote Sensing Applications Chinese Academy of Sciences Beijing 100101 China 2. Graduate university of Chinese Academy of sciences Beijing 100039 China 3. Department of Geography University of Maryland College Park MD 20742 USA 4. Forest Remote Sensing lab Research Institute of Forest Resource and Information Technology Chinese Academy of Forestry Beijing 100091 China

Because of the cloudy conditions during the rice growth period, rice is one of the agri-cultural crops most suited to monitoring with the SAR instruments. Backscatter response measured by SAR is correlated with rice conditions, including height, density, biomass and structure, which are variable at different growing stages. In this paper, multi-date ENVISAT ASAR Alternating Polarization Mode (APMode) imageries were acquired during the rice crop growing cycle. At the same time, the rice parameters were measured in field. A continuous canopy model was used to compute the back-scattering from rice fields during the growth cycle, and the relationship between rice parameters and radar backscattering coefficients from both ASAR and modeling was analyzed. The effects of polari-zation, incidence angle and polarization on radar backscattering coefficients were analyzed. It was found that simulated radar backscatter has similar trends as ASAR data. This will be meaningful for the further research of rice parameters estimation from ASAR data. Different features show signifi-cantly different signatures in ASAR images and they follow some certain laws, so rice area can be accurately mapped by using multi-temporal SAR images, then rice yield can be estimated.

关键词： rice, ASAR, radar backscattering, model.

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Low-frequency waves in magnetic reconnection

Low-frequency waves in magnetic reconnection

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日地活动现象中基本等离子体过程国际学术研讨会

作者： CHAI LiHui 1 ,LI Yi 1 ,WANG Shui 1 &SHEN Chao 2 1 school of earth and space sciences,university of science and technology of china,hefei 230026,china 2 National space science Center,Chinese Academy of sciences,Beijing 100190,china

The characteristics of low-frequency waves in magnetic reconnection are studied using two-dimensional hybrid simulation code. In a coordinate system moving with fluid,the time series of a magnetic field perpendicular to the magnetic reconnection plane,By, is transformed into the power spectrum via fast Fourier transformation,while the wave propagation direction and polarization are determined by minimum variance analysis of the electric *** results show that low-frequency Alfvén ion-cyclotron waves dominate the reconnection *** waves have frequencies 0-1Ωp（where Ωp is the local proton gyro frequency）and all are left-handed circularly *** these waves,large-amplitude turbulence,with frequencies of 0-0.6Ωp and isotropic propagation,dominates the outflow *** can cause the reversal of By in the quadrupole *** the inflow regions, dominant waves,propagating mainly parallel to the ambient magnetic field,have higher frequencies and smaller *** frequency of the main peak of wave energy is usually higher than 0.5Ωp.

关键词： magnetic reconnection low-frequency waves Alfvén-ion cyclotron waves Hall quadrupole structure

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Transverse instability and magnetic structures associated with electron phase space holes

Transverse instability and magnetic structures associated wi...

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中国科学院地质与地球物理研究所第11届（2011年度）学术年会

作者： Aimin Du,~1 Mingyu Wu,~2 Quanming Lu,~(2,a)) Can Huang,~2 and Shui Wang~2 1 Institute of Geology and Geophysics,Chinese Academy of sciences,Beijing 100029,china 2 cas key laboratory of basic plasma Physics,school of earth and space sciences, university of science and technology of china,hefei,Anhui 230026,china

Electron phase space holes(electron holes) are found to be unstable to the transverse instability. Two-dimensional(2D) electromagnetic particle-in-cell simulations are performed to investigate the structures of the fluctuating magnetic field associated with electron *** combined actions between the transverse instability and the stabilization by the background magnetic field (B=Be) lead a one-dimensional electron hole into several 2D electron holes which are isolated in both the x and y *** electrons trapped in these 2D electron holes suffer the electric field drift v=E×B/B due to the existence of the perpendicular electric field E,which generates the current along the z ***,the unipolar and bipolar stmctures are formed for the parallel cut of the fluctuating magnetic field along the x and y directions,*** the same time,these 2D electron holes move along the x direction,and the unipolar structures are formed for the parallel cut of the fluctuating magnetic field along the z direction.

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