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Coronal Magnetic Flux Rope Equilibria and Magnetic Helicity

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Chinese Journal of Astronomy and Astrophysics 2001年第1期1卷 77-84页

作者： You－QinHu Yan－WeiJiang 等 departmentofearthandspacescience UniversityofScienceandTechnologyofChinaHefei230026 departmentofEart

Using a 2.5-dimensional (2.5-D) ideal MHD model, this paper analyzes the equilibrium properties of coronal magnetic flux ropes in a bipolar ambient magnetic field. It is found that the geometrical features of the magnetic flux rope, including the height of the rope axis, the half-width of the ropes and the length of the vertical current sheet below the ropes are determined by a single magnetic parameter, the magnetic helicity, which is the sum of the self-helicity of the rope and the mutual helicity between the rope field and the ambient magnetic field. All the geometrical parameters increase monotonically with increasing magnetic helicity. The implication of this result in solar active phenomena is briefly discussed.

关键词： Sun: magnetic fields - Sun: magnetic flux rope - Sun: magnetic helicity

Sm-Nd isotopic ages of Tiqiushan eclogites in Xinyi region and its geological significance

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Chinese science Bulletin 1999年第S2期44卷 144-146页

作者： WANG Yinxi~(1,2), YANG Jiedong~(1,2), TAO Xiancong~(1,2), GE Ningjie~4. CHEN Peirong~3, FAN Chunfang~3 and LI Jianhua~5 1. Center of Modern Analysis, Nanjing University, Nanjing 210093, china 2. State Key Laboratory for Research of Mineral Deposits, Nanjing University, Nanjing 210093, china 3. department of earth {4., Nanjing University, Nanjing 210093, china 4. department of earth and space sciences, University of {4. and technology of chian, hefei 2.002., china 5. No.5 Geological Party of Jiangsu Province, Xuzhou 221005, china Center of Modern Analysis Nanjing University Nanjing 210093 China State Key Laboratory for Research of Mineral Deposits Nanjing University Nanjing 210093 China department of earth and space sciences University of Science and Technology of Chian Hefei 230026 China department of earth science Nanjing University Nanjing 210093 China No. 5 Geological Party of Jiangsu Province Xuzhou 221005 China

GEOLOGICAL scientists have paid much attention to the suture zones formed by collision between the Sino-Korean and Yangtze blocks because of the discovery of the ultrahigh pressue metamorphic (UHPM) rocksfrom northern Jiangsu Province (Su), southern Shandong Province (Lu) and the Dabie *** the age of 200-24. Ma is probably the best estimation for UHPM metamorphism in the DabieMountains, the primary intrusive and metamorphic ages of the complex from northern Jiangsu Provincehave not been determined before. Using the Sm-Nd isotopic dating method, our study is aimed at datingthe UHPM metanorphic event of northern Jiangsu Province and researching a probable relation between theUHPM rocks from the Dabie Mountains and the UHPM rocks from northern Jiangsu Province.

关键词： northern Jiangsu eclogite rocks Sm-Nd isotopic ages.

CONSTRUCTION OF EQUILIBRIUM P-T BUNDLES OF COMBINATION OF n+2 PHASES ON PETROGENETIC GRIDS

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science china Chemistry 1989年第2期32卷 193-204页

作者：程伟基王基镕郭其悌 department of earth and space sciences the University of Science and Technology of China Hefei department of Mathematics the University of Science and Technology of China Hefei Institute of Geochemistry Academia Sinica Guiyang

This paper first discusses the algorithm for balancing reactions of the combination of n + 2 phases around an invariant point on a P-Tdiagram, and then emphatically develops a new algorithm for the arrangement of univariant reaction lines, using a signum matrix V·F or S·F, where V and S are diagonal matrixes of signum of △V and △S in n+2 univariant reactions respectively, and F is a signum matrix of stoichiometric coefficients of phases in reactions. Using this new algorithm greatly simplifies relative computer programs, brings out the automatic construction of equilibrium P-T curves of combination of n +2 phases, and further makes it possible to construct a whole petrogenetic grid automatically

关键词： P-T bandles of combination of n + 2 phases.

Stratigraphy and TL Dating of Paleolithic Sites in the Luonan Basin,china

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人类学学报 2002年第S1期21卷 67-77页

作者： WANG She jiang(Shaanxi Provincial Institute of Archaeology, Xi’an, P. R. china 710054. HUANG Pei hua(department of earth and space {4., University of {4. and technology of china, hefei 2.002.)

Between 1995 and 1999 the Longyadong cave site and 50 open air Paleolithic sites were investigated and excavated in the Luonan Basin of china. A total of 1?751 stone artifacts were collected from open air sites, and fossils from about 20 animal species as well as 65?000 lithic artifacts were excavated from the cave site. This paper provides a preliminary study of site lithic stratigraphics in their geological context as well as the results of thermoluminescence (TL) dating. The TL dates of five soil samples place the sites into the middle to late period of the Middle Pleistocene (Q 2 2—3 ). Upon further taking into account strata relationships, three cultural periods were identified in Longyadong cave. When compared with the TL dates and stratigraphy from Zhoukoudian Locality 1, loess deposits in Shaanxi Luochuan, red earth in Anhui and deep sea records, Longyadong is in the range of 500—250 kyr, approximately the same timeframe as Zhoukoudian Locality 1.

关键词： Stratigraphy TL dating Paleolithic Longyadong Cave Open air Sites Luonan Basin

VELOCITY SHEAR INSTABILITY IN DUSTY PLASMAS OF COMET

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中国科学院上海天文台年刊 2000年 201-205页

作者： Lu Li Li Zhongyuan (department of earth and space sciences, University of {4. and technology of china, hefei 2.002.)

The velocity shear instability in a magnetized, three-component dusty plasma is investigated for both positively and negatively charged dust particles. The critical shears as a function of the relative charge of dust grains for both positively and negatively charged dust grains are in the same form. The instability excitation is easier in colder proton’s environment for positively charged dust, and so also in colder electron’s environment for negatively charged dust. For a certain flow pattern, the instability excites in different direction for different sign of charged dust grains. This conclusion may be helpful in interpreting the helical structures and streamer splitted phenomena in a cometary tail.

关键词： velocity shear instability - dusty plasma - cometary tail - comet plasma

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 2.002., china 3. department of Geology and Geophysics, University of California, Berkeley, CA 94.20, 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.

Pb isotope geochemistry of lead, zinc, gold and silver deposit clustered region, Liaodong rift zone,northeastern china

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science china earth sciences 2005年第4期48卷 467-476页

作者： CHEN Jiangfeng1, YU Gang1, XUE Chunji2, QIAN Hui1, HE Jianfeng1, XING Zhi1 & ZHANG Xun1 1. School of earth and space sciences, University of science and {4. of china, hefei 2.002., china 2. department of Geology, Chang’an University, Xi’an 710054. china 1. School of earth and space sciences University of Science and Technology of China 230026 Hefei China 2. department of Geology Chang’an University 710054 Xi’an China

Pb isotopic analyses were reported for sulfide and hydrothermal carbonate minerals and marble of the Xiquegou lead-zinc, the Zhenzigou zinc-lead and the Gaojiapuzi silver deposits from the Qingchengzi ore field and the Beiwagou zinc-lead deposit in the west, Proterozoic Liaodong rift zone. Pb isotopic ratios of the marble from the Qingchengzi ore field range from 18.24.to 30.63 for 206 Pb/204.b, 15.59 to 17.05 for207Pb/204.b and 37.4. to 38.63 for 208Pb/204.b. The marble gives a Pb-Pb isochron age of 1822±92 Ma, which is interpreted as the age of the metamorphism of the marble. Ore Pb, including Pb of sulfide and hydrothermal car- bonate minerals, from the Qingchengzi ore field shows limited variation with 206 Pb/204.b=17.66- 17.96, 207 Pb/204.b=15.60-15.74.and 208Pb/204.b=37.94.38.60. In contrast, ore Pb from the Beiwagou deposit gives different Pb isotopic ratios with 206Pb/204.b=15.68-15.81, 207 Pb/204.b= 15.34.15.4. and 208Pb/204.b=35.30-35.68. Pb of all deposits from the Liaodong rift zone is derived from the upper crust. Ore Pb of the Qingchengzi deposits is derived from a young upper crust. The model Th/U ratios of 4.4. to 4.74.for ore Pb are significantly different from that of 1.7 to 4.4.given by the marble of the Qingchengzi ore field, suggesting that marble is not the source of the ore Pb. Ore Pb of the Beiwagou deposit is extracted from its source and the deposit is formed at the Paleoproterozoic era. Different Pb isotopic ratios of the Qingchengzi ore field and the Beiwagou deposit are due to different ages of the deposits and suggest that the two types of deposits are derived from different sources and are possibly formed by different ore-forming processes.

关键词： Pb isotopes, source(s) of the ore-forming materials, origin of ore deposits, Liaodong rift zone.

Re-Os isotopic composition of the Dongling ⅢCD iron meteorite

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Chinese science Bulletin 2001年第6期46卷 518-520页

作者： SUN Weidong, DU Andao, YANG Gang, XIE Zhi & CHEN JiangfengDeparlmenl of earth and space sciences, Laboratory tor Chemical Geodynamics. University of science and {4. of china, hefei 2.002.. china:Institute of Rock and Mineral Analysis, Chinese Academy of Geological sciences. Beijing 100037, china department of earth and space sciences Laboratory for Chemical Geodynamics University of Science and Technology of China Hefei China Institute of Rock and Mineral Analysis Chinese Academy of Geological Sciences Beijing China

Re, Os concentrations and Os isotopic compositions of the Dongling ⅢCD iron meteorite were determined by N-TIMS technique. The result was compared with that of the other irons and chondrites. The Re and Os concentrations of the Dongling iron meteorite were plotted on the trends of the group ⅢA and ⅣA irons. The Pt-Os relation of the Dongling iron meteorite is similar to that of the group ⅡA irons. That suggests a higher fractionation for the Dongling iron meteorite.

关键词： Dongling iron meteorite Re-Os isotopes N-TIMS.

U-PB ZIRCON AGES OF TIANZHUSHAN GRANITES IN THE EASTERN DABIE OROGEN AND THEIR GEOLOGICAL IMPLICATIONS

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Scientia Geologica Sinica 1998年第4期 521-525页

作者： Ge Ningjie(department of earth and space sciences, University of {4. and technology of china, hefei, 2.002.)Wu Weiping (Anhui institute of Geological {4.)Liu Bin (department of earth and space sciences, University of {4. and technology of Chin

The precise U-Ph zircon dating of Tianzhushan granites indicates. the emplacement age of the intrusion is127 Ma. It is one part of the Large-scale magmatic emplacement in the extension environment after thecollision betWeen Yangtze Block (YB) and North china Block (NCB), and is belonged to the granitesformed after collision orogens. This large-scale tectonic magma event not only caused the emplacement ofgranitic intrusion and led to intense metamorphism and deformation of the rocks in Dabie area, but alsoplayed a very important role for the Dabie ultrahigh pressure (UHP) metamorphic rocks ultimatelyreturning to the each surface.

关键词： Pb U-PB ZIRCON AGES OF TIANZHUSHAN GRANITES IN THE EASTERN DABIE OROGEN AND THEIR GEOLOGICAL IMPLICATIONS Wang