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Pleonaste in Boxian meteorite

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Chinese science Bulletin 1998年第19期43卷 1656-1660页

作者： WANG Kuiren and HONG Ji’an Department of earth and Space sciences, University of science and Technology of china advanced research center for earth sciences and astronomy, University of science and Technology of china, third world academy of sciences Department of earth and Space sciences University of Science and Technology of China China advanced research center for earth sciences and astronomy University of Science and Technology of China Third World Academy of Sciences Hefei China

There are three kinds of occurrence of pleonaste, a rare meteoritic mineral, totally found in Boxian meteorite. They are as the following: (ⅰ) occurring in the inner circle of the chondrule edge, of which a circle texture is composed; (ⅱ) occurring in the state of inclusions, included in an olivine chondrule, with close paragenesis of wadsleyite; (ⅲ) occurring in the state of porphyry. The chondrule in the first occurrence belongs to CA chondrules. The chemical compositions of pleonaste are heterogeneity except for the atomic ratios of Fe/(Mg+Fe), which can be attributed to the following reasons: (ⅰ) they are congenetic minerals; (ⅱ) the heterogeneity of the compositions of the solar clouds in the early states; (ⅲ) the chondrites are the multiple-stage evolution; (ⅳ) the further proof of Boxian meteorite is an unequilibrium common chondrite.

关键词： rare pleonaste in meteorites found genesis.

Oxidation Experiment of Natural Megacrystal Ch'nopyroxene: Implications for Assignment of Mossbauer Spectra

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Acta Geologica Sinica(English Edition) 2001年第1期 51-58页

作者： ZHI Xiachen, CHEN PengDepartment of earth and Space sciences, University of science and Technology of china Laboratory of Chemical Geodynamics, ustc advanced research center for earth science and astronomy in ustc, third world academy of science, hefei 23.026 LIN Chengzhong, CHEN Shuqing, ZHANG GuilanInstitute of Mineral Resources, Chinese academy of Geology sciences, Beijing 100037LI Yuzhi and LIN Lei Open Laboratory of Structure Analysis, ustc, hefei 23.026

The Mossbauer spectra of natural megacrystal clinopyroxene are usually fitted by 4 sets of symmetric doublets, A-A', B-B', C-C' and D-D', respectively, in terms of increasing Qs value in literature. But the assignments of those doublets are quite different, except the D-D' doublet assigned to Fe3+ at the lattice site Ml in previous papers. Particularly, the assignment and interpretation of the C-C' doublet are *** oxidation experiments of natural megacrystal clinopyroxene collected from the Hannuoba basalt, North china, were performed under controlled conditions of temperature at 1000℃ and oxygen fugacity of FMQ buffer in 1, 2, 3 and 5 days respectively. The oxidized samples were then measured by X-ray diffraction spectrometry and Mossbauer spectrometry. The oxidation of clinopyroxene is characterized by Fe2+→ Fe3+ at Ml under the subsolidus conditions, which is consistent with the increase of the area of the D-D' doublet when the heating time increases. Accordingly, the area of the A-A' and B

关键词： megacrystal clinopyroxene Mossbauer spectrum oxidation experiment anomalous doublet

advanced information feedback strategy in intelligent two-route traffic flow systems

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science china(Information sciences) 2010年第11期53卷 2265-2271页

作者： DONG ChuanFei1,2, MA Xu1,3 & WANG BingHong1,4 1Department of Modern Physics and Nonlinear science center, University of science and Technology of china (ustc), hefei 23.026, china 2School of earth and Atmospheric sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA 3 Department of Physics, Syracuse University, Syracuse, NY 13244, USA 4The research center for Complex System science, University of Shanghai for science and Technology and Shanghai academy of System science, Shanghai 200093, china Department of Modern Physics and Nonlinear science center University of Science and Technology of China (USTC) Hefei China School of earth and Atmospheric sciences Georgia Institute of Technology Atlanta USA Department of Physics Syracuse University Syracuse USA The research center for Complex System science University of Shanghai for Science and Technology and Shanghai Academy of System Science Shanghai China

The optimal information feedback has a significant effect on many socioeconomic systems like stock market and traffic systems aiming to make full use of resources. In this paper, we study dynamics of traffic flow with real-time information. The influence of a feedback strategy named vehicle number feedback strategy (VNFS) is introduced, in which we only calculate the vehicle number of first 500 route sites from the entrance. Moreover, the two-route traffic system has only one entrance and one exit, which is different from those in the previous work. Our model incorporates the effects of adaptability into the cellular automaton models of traffic flow, and simulation results by adopting this optimal information feedback strategy have demonstrated higher efficiency in controlling spatial distribution of traffic patterns than the other three information feedback strategies, i.e., TTFS, MVFS and CCFS.

关键词： vehicle number feedback strategy two-route selecting traffic flow intelligent vehicle cellular automaton model

Measurement of Attenuation Q Value of Cylindrical Sample from Wave Energy

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earthquake research in china 2000年第2期14卷 16-22页

作者： Shi Xingjue, Ye Lin, Zhao Cuiping, Li Guangquan and Li WeidongDepartment of earth and Space sciences, University of science and Technology of china,advanced center for earth science and astronomy, third world academy of science, hefei 23.026, china Department of earth and Space sciences University of Science and Technology of ChinaAdvanced Center for Earth Science and AstronomyThird World Academy of ScienceHefei 230026China

Two methods for measuring the attenuation Q value,frequency-amplitude ratio method andwaveform inversion method,were *** size and shape of most rock samples in thelaboratory can hardly fulfill the rigorous requirements of the above methods.A new testmethod of using the wave energy to calculate the Q value was *** principle,calculation formulae and some points for attention were expounded;the relationship betweenQ_P and Q_E was discussed;and many samples were measured by this *** result wascompared with those by other methods,and it was considered that the Q value by this methodlies between Q_P and Q_E·

关键词： Attenuation Ultrasonic wave Energy

Thresholds of geographic environmental elements in sediment yield of drainage basins

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science china earth sciences 2005年第2期48卷 230-240页

作者： CHEN Hao, ZHOU Jinxing, CAI Qiangguo, LU Zhongchen & LI Zhongyan Institute of Geographic sciences and Natural Resources research, Chinese academy of sciences, Beijing 100101, china Institute of Forestry science, Chinese academy of Forestry science, Beijing 100091, china research center for Eco-Environment sciences, Chinese academy of sciences, Beijing 100085, china Computing Institute of science and Engineering, North china Electric Power University, Beijing 102206, china Institute of Geographic sciences and Natural Resources research Chinese Academy of Sciences Beijing China Institute of Forestry science Chinese Academy of Forestry Science Beijing China research center for Eco-Environment sciences Chinese Academy of Sciences Beijing China Computing Institute of science and Engineering North China Electric Power University Beijing China

Threshold of environmental elements in drainage basin sediment yield refers to, under effect of climate, underlying surface and human activity, a turning point of abrupt changes in drainage sediment yield related to environmental element characteristics. Previous studies on threshold of sediment yield of relevant drainage basins were mainly concentrated on impact of natural zones with a few researches on impact of other environmental elements. Particularly studies on compound environmental element threshold in drainage basin sediment yield remain blank today. Studies indicate that sediment yield in drainage basins is affected by compound interactions and complex actions. Based on single element analysis, the present paper gives quantitatively compound threshold of environmental elements affecting sediment yield of the drainage basin between Hekouzhen and Tongguan in the middle Yellow River by the method of multi-variant, polynomial formula regression analysis.

关键词： middle Yellow River, environmental element, sediment, sediment delivery mudule, threshold.

Lunar ~3He estimations and related parameters analyses

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science china earth sciences 2010年第8期53卷 1103-1114页

作者： LI DiHui, LIU HeGuang, ZHANG WeiGuo, LI Yun & XU ChuanDong center for Space science and Applied research, Chinese academy of sciences, Beijing 100190, china center for Space science and Applied research Chinese Academy of Sciences Beijing China

As a potential nuclear fuel, 3He element is significant for both the solution of impending human energy crisis and the conservation of natural environment. Lunar regolith contains abundant and easily extracted 3He. Based on the analyses of the impact factors of 3He abundance, here we have compared a few key assessment parameters and approaches used in lunar regolith 3He reserve estimation and some representative estimation results, and discussed the issues concerned in 3He abundance variation and 3He reserve estimation. Our studies suggest that in a range of at least meters deep, 3He abundance in lunar regolith is homogeneously distributed and generally does not depend on the depth; lunar regolith has long been in a saturation state of 3He trapped by minerals through chemical bonds, and the temperature fluctuation on the lunar surface exerts little influence on the lattice 3He abundance. In terms of above conclusions and the newest lunar regolith depth data from the microwave brightness temperature retrieval of the "ChangE-1" Lunar Microwave Sounder, a new 3He reserve estimation has been presented.

关键词： lunar regolith 3He abundance reserve estimation maturity granularity composition solar wind flux CELMS

Effect of upward ion on field-aligned currents in the near-earth magnetotail

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science china(Physics,Mechanics & astronomy) 2007年第5期50卷 673-680页

作者： ZHANG LingQian1, LIU ZhenXing1, MA ZhiWei2, SHEN Chao1, ZHOU XuZhi3 & ZHANG XianGuo3 1 center for Space and Applied research, Chinese academy of sciences, Beijing 100080, china 2 Institute of Plasma Physics, Chinese academy of sciences, hefei 230031, china 3 School of earth and Space science, Peking University, Beijing 100871, china center for Space and Applied research Chinese Academy of Sciences Beijing China Institute of Plasma Physics Chinese Academy of Sciences Hefei China School of earth and Space science Peking University Beijing China

A 3-dimensional resistive MHD simulation was carried out to study the effect of the upward ions on the field-aligned currents (FACs) in the near-earth magnetotail. The simulation results show that the up-flow ions originating from the nightside auroral oval would drift into the center plasma sheet along the magnetic field lines in the plasma sheet boundary, and have an important effect on the field-aligned currents. The main conclusions include that: 1) the upward-ions mainly affect the field- aligned currents in the near-earth magnetotail (inside 15 Re); 2) the generated FACs in the near-earth region have two types, i.e., Region 1 FAC in the high-latitude and Region 2 FAC in the low-latitude; 3) FACs increase with the enhancement of the upward ion flux; 4) with the same flux of the upward ions, FACs enhance with the increase of the velocity of the up-flow ions; 5) the intensification of FACs is also closely related with the latitude of the upward ions, and the ions from the closed field line region generate larger FACs; 6) the generation of FACs is closely related with By created by the upward ions.

关键词： up-flow ions, near-earth magnetotail, field-aligned current

Re-Os(ICP-MS)dating of the massive sulfide ores from the Jinchuan Ni-Cu-PGE deposit

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science china earth sciences 2005年第10期48卷 1672-1677页

作者： YANG Gang1,2, DU Andao1, LU Jiren3, QU Wenjun1 & CHEN Jiangfeng2 1. National research center of Geoanalysis, Beijing 100037, china 2. Laboratory for earth Material Cycling, School of earth and Space sciences, University of science and Technology of china, hefei 23.026, china 3. Institute of Mineral Resource, Chinese academy of Geological sciences, Beijing 100037, china National research center of Geoanalysis University of science and Technology of china Chinese academy of Geological sciences

Massive sulfide ore from the Jinchuan Ni-Cu-PGE deposit was dated by Re-Os technique using Carius Tube digestion, Os distillation, Re extraction by acetone and ICP-MS measurement. An isochron giving an age of 833 ± 35 Ma, initial 187Os/188Os ratio of 0.279 ± 0.018 (MSWD = 1.7) and γOs = 130 ± 15 is obtained. The Re-Os age obtained agrees, within analytical uncertainties, with previous SHRIMP zircon U-Pb age of 827 ± 8 Ma (n=5, MSWD = 4.3). The result suggests that the deposit was formed at Neoproterozoic and that the formation of the Jinchuan Ni-Cu-PGE sulfide deposit may be closely related to the plume activity, which were attributed to the breakup of the Rodinia supercontinent. The high γOs of the massive ores sug-gests that crustal material was involved in the formation of the Jinchuan deposit, however, the quantity of the added crustal material is less than 10%.

关键词： Jinchuan Ni-Cu-PGE deposit, Re-Os dating, ICP-MS.

Numerical study of successive CMEs during November 4―5, 1998

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science china(Technological sciences) 2008年第10期51卷 1600-1610页

作者： ZHOU YuFen & FENG XueShang SIGMA Weather Group, State Key Laboratory for Space Weather, center for Space science and Applied research, Chinese academy of sciences, Beijing 100190, china SIGMA Weather Group State Key Laboratory for Space Weather Center for Space Science and Applied Research Chinese Academy of Sciences Beijing China

We present the solar-terrestrial transit process of three successive coronal mass ejections (CMEs) of November 4―5, 1998 originating from active region 8375 by using a time-dependent three-dimensional magnetohydrodynamics (MHD) simula-tion. These CMEs interacted with each other while they were propagating in inter-planetary space and finally formed a "complex ejecta". A newly developed SIP-CESE MHD model was applied to solve MHD equations numerically. The quiet solar wind was started from Parker-like 1D solar wind solution and the magnetic field map was calculated from the solar photospheric magnetic field data. In our simulation, the ejections were initiated using pulse in the real active region 8375. The interplanetary disturbance parameters, such as speed, direction and angular size of the expanding CME, were determined from the SOHO/LASCO data with the cone-model. We discussed the three-dimensional aspects of the propagation, in-teraction and merging of the three ejections. The simulated interplanetary shocks were compared with the nearby-earth measurement. The results showed that our simulation could reproduce and explain some of the general features observed by satellite for the "complex ejecta".

关键词： complex ejecta three-dimensional MHD simulation SIP-CESE MHD model