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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 {4. 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 {4. 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 {4. center for earth Science and astronomy in ustc, third world academy of Science, hefei 2.002. 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 2.002.

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

Sorption behavior of U(VI), ^(234.U(VI) and ^(238)U(VI) onto fracture-filling clays in Beishan granite, Gansu: Application to selecting the site of high-level radwaste repository in china

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Science china earth Sciences 2005年第10期48卷 1649-1655页

作者： MIN Maozhong1,2, LUO Xingzhang3, WANG Ju4. JIN Yuanxin4.& WANG Rucheng1 1. Department of earth Sciences, State Key Laboratory of Mineral Deposit research, Nanjing University, Nanjing 210093, china 2. center of Materials Analysis, Nanjing University, Nanjing 210093, china 3. Department of Environmental Science and Engineering, Nanjing University, Nanjing 210093, china 4. Beijing Geology Institute, Nuclear Industry, Beijing 100029, china Department of earth Sciences State Key Laboratory of Mineral Deposit Research Nanjing University Nanjing China center of Materials Analysis Nanjing University Nanjing china Department of Environmental Science and Engineering Nanjing University Nanjing china Beijing Geology Institute Nuclear Industry Beijing china

The first results of sorption experiments of U(VI), 234.(VI) and 238U(VI) onto original (unpurified) fracture-filling clays from No.1 monzonitic granite intrusion, Beishan area, Gansu Province, china are reported. The monzonitic granite intrusion is a potential location for a high-level radwaste (HLW) repository in china. The present experimental results show that the maximum U(VI) sorption reached 92% at near-neutral pH and the distribution coefficient (Kd) was 1226 mL/g. A high sorption capacity of the fracture-filling clays in host rock on radioactive ele-ments is necessary for HLW deep geological disposal repository. No preferential sorption of 234. onto the clays was found. Finally, the sorption of U(VI) onto the clays was also modeled using a surface complexation model.

关键词： HLW geological disposal repository, granite, uranium, radionuclide, clay, sorption.

U-Pb dating of zircon from the bed parallel anatectic granitic intrusion in the Baoban group in Hainan Island and the tectonic implication

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Science china earth Sciences 2005年第12期48卷 2092-2103页

作者： DING Shijiang1, HU Jianmin2, SONG Biao3,4. CHEN Mulun1, XIE Shengzhou1 & FAN Yuan1 1. Geological Surveying Institute of Hainan, Haikou 570206, china 2. Institute of Geomechanics, Chinese academy of Geological Sciences, Beijing 100081, china 3. Beijing center of SHRIMP, Beijing 100037, china 4. Institute of Geology, Chinese academy of Geological Sciences, Beijing 100037, china 1. Geological Surveying Institute of Hainan 570206 Haikou China 2. Institute of Geomechanics Chinese Academy of Geological Sciences 100081 Beijing China 3. Beijing center of SHRIMP 100037 Beijing China 4. Institute of Geology Chinese Academy of Geological Sciences 100037 Beijing China

The petrological and geochemical features of the bed parallel granitic intrusion in the Pre-Cambrian Baoban group in Hainan Island attest to the anatexis origin of the granites. U-Pb dating analyses of zircons from the anatectic granite and the biotite two-feldspar gneiss in the Baoban group, using SHRIMP II in the Beijing Ion-probe center, acquire 206Pb/238U ages of 368±3.5 Ma (of granite, 95% confidence level, MSDW=1.23) and 362.9±6.1 Ma (of gneiss, 95% confidence level, MSDW = 2.04. respectively. The two late Devonian ages indicate consistently a tectonic- thermal event experienced in Hainan Island, and are the first discovered record of the Devonian geological process in the district. This event possibly resulted from the deep ther-mal-dynamic process when the Gondwana continent began to break up in the Devonian period.

关键词： Hainan Island, Devonian period, anatectic granite, zircon SHRIMP U-Pb dating.

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 2.002., china 2School of earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA 3 Department of Physics, Syracuse University, Syracuse, NY 1324., USA 4.he research center for Complex System Science, University of Shanghai for Science and Technology and Shanghai academy of System Science, Shanghai 200093, china 1. Department of Modern Physics and Nonlinear Science center University of Science and Technology of China (USTC) Hefei 230026 China2. School of Earth and Atmospheric Sciences Georgia Institute of Technology Atlanta GA 30332 USA3. Department of Physics Syracuse University Syracuse NY 13244 USA4. The Research Center for Complex System Science University of Shanghai for Science and Technology and Shanghai Academy of System Science Shanghai 200093 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

The impact of vegetation restoration on erosion-induced sediment yield in the middle Yellow River and management prospect

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Science china earth Sciences 2005年第6期48卷 724-741页

作者： CHEN Hao1, ZHOU Jinxing2, CAI Qiangguo1, YUE Zhongqi3, LU Zhongchen4. LIANG Guanglin1& HUANG Jianguo5 1. Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Re-search, Chinese academy of Sciences, Beijing 100101, china 2. Institute of Forestry, Chinese academy of Forestry Sciences, Beijing 100091, china 3. Department of Civil Engineering, University of Hong Kong, Hong Kong, china 4. Eco-environmental research center, Chinese academy of Sciences, Beijing 100085, china 5. College of Resources and Environment, Southwest Agricultural University, Chongqing 4.0716, china Correspondence should be addressed to Chen Hao 1. Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences 100101 Beijing China 2. Institute of Forestry Chinese Academy of Forestry Sciences 100091 Beijing China 3. Department of Civil Engineering University of Hong Kong Hong Kong China 4. Eco-environmental research center Chinese Academy of Sciences 100085 Beijing China 5. College of Resources and Environment Southwest Agricultural University 400716 Chongqing China

According to the characteristics of water and erosion environments of different natural zones on the Loess Plateau, this paper studies changes of vegetation types, distribution boundaries of forest and grass as well as restoration capacity of vegetation in different natural zones in the middle Yellow River. The annual precipitation of 530 mm is the critical annual pre-cipitation for forest and grass distribution in the middle Yellow River. Among the zonal and azonal environmental factors affecting watershed sediment yield, the intermediate diameter D50 (mm) of suspended load and forest coverage (V, %) play the leading role. Of them the effect weight of forest coverage (V, %) on catchments sediment yield is only 3.4. less than the role of the intermediate diameter (D50, mm), they are almost the same. To effectively control soil erosion in semiarid, especially in hilly-gullied areas and make sediment transport modulus reduce to less than 6000 t/km2, it is rather difficult by merely relying on natural restoration of forest. In the process of cultivated land conversion into forest land and grassland, measures suiting local conditions should be adopted in tree species selection and artificial afforestation (grass planting) based on management with biological measures for slopeland and engineering measures for hilly-gullied areas, so that watershed forest coverage in key counties can reach at least over 30%.Compared with the standard period of precipitation prior to the 1960s, with the decrease of an-nual precipitation at various periods, plant productivities decline to different degrees under natural conditions. The main reason accountable for the low survival rate of new seedlings and grass over years is due to precipitation decrease. In light with regression models of annual pre-cipitation and natural vegetation productivities, it is possible to obtain estimated values of wa-tershed natural vegetation productivity and eco-water consumption needed for the restoration to

关键词： vegetation restoration, eco-water requirement, watershed sediment yield, the middle Yellow River.

Lithosphere types in North china:Evidence from geology and geophysics

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Science china earth Sciences 2005年第11期48卷 1809-1827页

作者： QIU Ruizhao1,2, DENG Jinfu3, ZHOU Su3, LI Jinfa4. XIAO Qinghui1,5, WU Zongxu6 & LIU Cui3 1. Institute of Geology, Chinese academy of Geological Sciences, Beijing 100037, china 2. Development and research center, china Geological Survey, Beijing 100037, china 3. china University of Geosciences, Beijing 100083, china 4. china University of Geosciences, Wuhan 4.0074. china 5. Information center of Ministry of Land and Resources, Beijing 100812, china 6. Institute of Geology, State Seismological Bureau, Beijing 100029, china 1. Institute of Geology Chinese Academy of Geological Sciences 100037 Beijing China 2. Development and research center China Geological Survey 100037 Beijing China 3. china University of Geosciences 100083 Beijing China 4. china University of Geosciences 430074 Wuhan China 5. Information center of Ministry of Land and Resources 100812 Beijing China 6. Institute of Geology State Seismological Bureau 100029 Beijing China

On the basis of the characteristics of geology and geophysics in North china, three types of lithosphere, namely, the cratonic, the orogenic and the rift lithospheres can be classified. In terms of petrological method (based on the information from Precambrian rock assemblages, igneous activities, deep-seated enclaves, etc.) and the relationship between seismic velocity and rock compositions, the crust-mantle petrological and chemical structure models can be set up. researching results indicate that the geology and geophysics of North china platform bears the similar characteristics in comparison with those of the global typical cratons. The Eerduosi(Ordos) block located in the west of the North china Platform is a remnant of cratonic lithosphere after the North china platform had undergone “activation” in Mesozoic and “reconstruction” in Cenozoic times. The continental crust consists mainly of TTG rock assemblage while the subcontinental lithosphere mantle mainly consists of strongly depleted harzburgite. The craton was finally formed in late Archaean and early Proterozoic, and has been kept in stability up to present; its crustal-mantle petrological structures of lithosphere can be set up as a reference for the study of North china craton and even Sino-Korean craton. In the Mesozoic period, the middle and east areas of North china platform were activated in the Yanshanian orogenic process, the continental crust was reformed by material and heat-transfer of convective mantle and the original crustal TTG component was reconstructed to be granitic crust, and the subcontinental lithosphere man- tle was replaced by the Yanshanian harzburgite-lherzolite. The Yanshan-Taihang Mountains were the remnants of orogenic lithosphere after the rifting in eastern North china in Cenozoic. The present thickness of continental crust and lithosphere in the Yanshan-Taihang Mountains is not equal to their thickness during the Yanshanian orogenic movement because they had undergone the

关键词： lithospheric types,evidence of geology and geophysics,crust-mantle petrological structure,deep process

The onset and advance of the Asian summer monsoon

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Science Bulletin 2006年第1期51卷 80-88页

作者： Lü Junmei1,2,4. ZHANG Qingyun1, TAO Shiyan1 & JU Jianhua3 1. State Key Laboratory of Numerical Modeling for Atmospheric Sci- ences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese academy of Sciences, Beijing 100029, china 2. Department of Atmospheric Sciences, Yunnan University, Kunming 650091, china 3. china Meteorological Administration Training Centre, Beijing 100081, china 4. Graduate School of Chinese academy of Sciences, Beijing 100039, china State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Department of Atmospheric Sciences Yunnan University Kunming 650091 China Graduate School of Chinese academy of Sciences Beijing 100039 China china Meteorological Administration Training Centre Beijing 100081 China

Based on the daily outgoing longwave radiation (OLR) data from National Oceanic and At- mospheric Administration (NOAA) satellites, the Cli- mate Prediction center’s merged analysis of pre- cipitation (CMAP) data and the National centers for Environmental Prediction/National center for At- mospheric research (NCEP/NCAR) reanalysis dataset, the mean intraseasonal variability of the Asian summer monsoon (ASM) is investigated by using power spectrum analysis, band-pass filter, and diagnostic analyses. The processes of the onset and {4. of monsoon over the southern part of Indo- china Peninsula, the east coast of Bay of Bengal, the South china Sea and the Indian subcontinent are explored. It is found that there is an abrupt change in OLR, precipitation and zonal wind during the onset and {4. of the ASM. It is also indicated that the southern part of Indochina Peninsula and the adja- cent Andaman Sea is the region where the earliest onset of the ASM occurs in the 2nd pentad of May.

关键词： Asian summer monsoon intraseasonal variability onset advance.

Mesozoic subduction-accretion zone in northeastern South china Sea inferred from geophysical interpretations

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Science china earth Sciences 2006年第5期49卷 471-482页

作者： ZHOU Di1, WANG Wanyin2, WANG Jialin3, PANG Xiong4. CAI Dongsheng5 & SUN Zhen1 1. Key Laboratory of Marginal Sea Geology, South china Sea Institute of Oceanology, Chinese academy of Sciences, Guang- zhou 510301, china 2. College of Geological and Topographical Engineering, Chang’an University, Xi’an 710054. china 3. Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, china 4. china National Offshore Oil Co. Limited – Shenzhen Branch, Shenzhen 518067, china 5. china National Offshore Oil Co. Limited – research center, Beijing 100027, china 1. Key Laboratory of Marginal Sea Geology South China Sea Institute of Oceanology Chinese Academy of Sciences Guangzhou 510301 China 2. College of Geological and Topographical Engineering Chang’an University Xi’an 710054 China 3. Key Laboratory of Marine Geology Tongji University Shanghai 200092 China 4. china National Offshore Oil Co. Limited — Shenzhen Branch Shenzhen 518067 China 5. china National Offshore Oil Co. Limited — research center Beijing 100027 China

A segment of Mesozoic subduction-accretion zone was inferred across thenortheastern South china Sea at approximately NE4.0 orientation. Basic evidence includes thefollowing: A belt of peek gross horizontal Bouguer gravity gradient (PGHGBA) is comparable in sizeand intensity to that of the Manila subduction-accretion zone. A belt of high positive magneticanomalies appears to the north and sub-parallel to the PGHGBA, representing the volcanic arcassociated to the subduction zone. The PGHGBA crosses obliquely both Cenozoic structures and presentseafloor topography, indicating a pre-Cenozoic age. The segment is offset left-laterally byNW-running strike-slip faults, in concord with the Mesozoic stress field of South china. Inaddition, the existence of the subduction zone is supported by wide-angle seismic data obtained indifferent years by different institutions. At approximate localities, a north-dipping ramp of Mohosurface is indicated by records of ocean-bottom seismometers, and a strong reflector about 8 kmbeneath the Moho reflector is indicated by both OBS and long-cable seismic records. Theidentification of a segment of Mesozoic subduction zone in NE South china Sea fills nicely the gapof the Great Late Mesozoic Circum SE Asia Subduction-acrretion Zone, which extended from Sumatra,Java, SE Kalimantan to N Palawan, and from Taiwan, Ryukyu to SW Japan.

关键词： Mesozoic, subduction zone, SE Asia, NE South china Sea, geophysics.