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Progress and review of the studies on the end-Triassic mass extinction event

Science china.Earth Sciences 2005年第12期48卷 2049-2060页

作者： DENG Shenghui1,2. LU Yuanzheng1,2.3 & XU Daoyi4 1. research institute of Petroleum Exploration and Development, {2. 100083, china.2. Key Laboratory of Oil and Gas Reservoir of Petrochina. {2. 100083, china.3. china.University of Geosciences, {2. 100083, china.4. institute of Geology, china.Earthquake Administration, {2. 10002., china 1. research institute of Petroleum Exploration and Development 100083 Beijing China 2. Key Laboratory of Oil and Gas Reservoir of Petrochina 100083 Beijing China 3. china.University of Geosciences 100083 Beijing China 4. institute of Geology China Earthquake Administration 100029 Beijing China

The mass extinction at the end-Triassic is one of the five biggest in the Phanerozoic. However,it is the least well understood among these five events, and only till last decade it became a great academic interesting subject to geologists. The evidences for this event come obviously from bivalves, brachiopods, ammonites, corals, radiolaria, ostracods and foraminifera of marine habitats, and plants and tetrapods of terrestrial realm. By contrast, for some of other groups, such as marine gastropods and marine vertebrates, no mass extinction has been recog-nized yet. The extinction event is strongly marked at specific level but shown a complicated situa-tion at generic and family levels. Dramatic changing of the environment, such as the temperature raise due to the greenhouse effect, the marine anoxic habitats caused by a sudden transgression after the regression at the end of Triassic, has been claimed to be the main cause of the extinction. Many hypotheses have been suggested to demonstrate the mechanisms of the environment changing, among which two popular ones are the bolide impact and volcanic eruption. The Triassic-Jurassic (Tr-J) boundary mass extinction event is still poorly understood because no enough data have been obtained from the Tr-J boundary successional sections of both marine and terrestrial sediments, and most of these studies were regionally restricted. The basic aspects of the event and its associated environmental conditions remain poorly characterized and the causal mechanism or mechanisms are equivocal. Some authors even doubt its occurrence. china.has many successionally developed terrestrial and marine Tr-J sections. Detailed studies of these sections may be important and significant for well understanding of the event.

关键词： progress, review, end-Triassic, mass extinction, mechanism, Tr-J boundary.

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Spectral analysis of quasi-stationary sea surface topography from GRACE mission

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Science china.Earth Sciences 2005年第11期48卷 2040-2048页

作者： ZHANG Zizhan1,2.& LU Yang1,3 1. institute of Geodesy and Geophysics, Chinese academy of Sciences, Wuhan 430077, {2.2. Graduate School of the Chinese academy of Sciences, beijing 100039, {2.3. Unite Center for Astro-geodymics research, Chinese academy of Sciences, Shanghai 2.0030, china 1. institute of Geodesy and Geophysics Chinese Academy of Sciences 430077 Wuhan China 2. Graduate School of the Chinese academy of Sciences 100039 Beijing China 3. Unite Center for Astro-geodymics research Chinese Academy of Sciences 200030 Shanghai China

During the last two decades satellite altimetry has offered an abundance of meas-urements of the sea surface resulting in the improvement of global mean sea surface height (MSSH) and marine geoid determination. On the other hand, with the launching of new genera-tion gravity satellites, some high accuracy long-wavelength gravity models are available. These breakthroughs give us a great opportunity for new estimation of quasi-stationary sea surface topography (QSST). In this paper, the new gravity model GGM01C derived from GRACE mission is briefly presented, and a new global high precision and high-resolution QSST is determined based on the GGM01C model and the global MSSH. The spectral features of the QSST esti-mated by GGM01C and EGM96 gravity model to degree/order 2.0 are discussed by spectral analysis. As a result, the QSST is mainly composed of long waves, medium waves partially and short waves scarcely, its power spectral structures are different between the zonal direction and the meridional direction, there are great differences between the two models, which maybe ex-plain why the ocean currents derived from the two gravity models by Tapley show different pat-terns.

关键词： quasi-stationary sea surface topography, mean sea surface height, GGM01, fast Fourier transform, spectral analysis

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CH_4 uptake flux of Leymus chinensis steppe during rapid growth season in Inner Mongolia,china

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Science china.Earth Sciences 2010年第7期53卷 977-983页

作者： GENG YuanBo1, LUO GuangQiang1,2.& YUAN GuoFu1 1 institute of Geographic Sciences and Natural Resources research, Chinese {2. of Sciences, beijing 100101, china.2.Graduate University of Chinese {2. of Sciences, beijing 100049, china 1. institute of Geographic Sciences and Natural Resources research Chinese Academy of Sciences Beijing 100101 China2. Graduate University of Chinese Academy of Sciences Beijing 100049 China

The influence of near ground atmosphere CH4 concentration, soil water content, soil Eh, plants, soil temperature, and pH on CH4 uptake flux of Leymus chinensis steppe during rapid growth season was studied using field in-situ measurement in Xilin River basin of Inner Mongolia, china. The results showed that CH4 uptake flux was positively correlated with near ground atmosphere CH4 concentration and soil Eh but negatively correlated with soil water content. Precipitation may decrease the CH4 flux by increasing the soil water content. The average fluxes of three treatments during the observation period were 1.52.(natural conditions, 1.51 (aboveground plants were excluded), and 2.00 mg m?2.d?1 (all plants were removed), respectively. The difference between the CH4 flux of natural condition treatment and that of removing aboveground plants treatment is small, whereas the flux of removing all plants treatment is larger than the other two treatments. This means that the contribution of aboveground plants to CH4 uptake flux is smaller than that of roots or roots-removing process. CH4 uptake flux is not sensitive to soil temperature and the narrow-ranged soil pH (6.36–7.86). The Leymus chinensis steppe acts as a sink for CH4, and thus more studies should be focused on its affecting factors and related mechanisms.

关键词： CH4 uptake flux Leymus chinensis steppe affecting factors static opaque chamber/gas chromatography method

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Main Timber Legality Verification Schemes in the World

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Chinese forestry Science and Technology 2010年第3期9卷 50-55页

作者： SU Haiying1 REN Haiqing1 CHEN Yong2.1.research institute of Wood Industry,Chinese {2. of forestry,beijing 100091,P.R.china.2.research institute of forestry Policy and Information,Chinese {2. of forestry,beijing 10091,P.R.china

Based on introduction of the timber legality verification schemes,the article provides a detailed review of existing legality verification schemes covering aspects such as definition of legality,verification *** aims to help Chinese companies understand the different requirements and evidence of compliance required by legislation,public and private procurement policies.

关键词： timber legality verification

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Survival probability and ruin probability of a risk model

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Applied Mathematics(A Journal of Chinese Universities) 2008年第3期23卷 256-264页

作者： LUO Jian-hua College of Science,Central South University of forestry and Technology,Changsha 410004,china.{2. of Statistics,Central South University of forestry and Technology,Changsha 410004,china. College of Science Central South University of Forestry and Technology Changsha 410004 China institute of Statistics Central South University of Forestry and Technology Changsha 410004 China

In this paper, a new risk model is studied in which the rate of premium income is regarded as a random variable, the arrival of insurance policies is a Poisson process and the process of claim occurring is p-thinning process. The integral representations of the survival probability are gotten. The explicit formula of the survival probability on the infinite interval is obtained in the special casc cxponential *** Lundberg inequality and the common formula of the ruin probability are gotten in terms of some techniques from martingale theory.

关键词： risk model thinning process survival probability martingale ruin probability integral representation

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The species diversity of fusulinaceans and high-frequency sea-level changes in the Carboniferous-Permian boundary section at Xikou, Zhen'an County,Shaanxi Province, china

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Science china.Earth Sciences 2006年第7期49卷 673-683页

作者： ZHANG Haijun1, WANG Xunlian2. DING Lin1, XIA Guoying3 & WANG Lei2.1. institute of Tibetan Plateau research, Chinese {2. of Sciences, beijing 100085, china.2. Faculty of Earth Sciences and Mineral Resources, china.University of Geosciences, beijing 100083, china.3. Tianjin institute of Geology and Mineral Resources, Tianjin 300170, china 1. institute of Tibetan Plateau research Chinese Academy of Sciences Beijing 100085 China 2. Faculty of Earth Sciences and Mineral Resources China University of Geosciences Beijing 100083 China 3. Tianjin institute of Geology and Mineral Resources Tianjin 300170 China

The study on the interrelation between sea-level changes and biodiversity with its evolu-tion has great significance for understanding the impact of global changes on organic evolution and exploring the inherent laws of life-environment coevolution in geological history. In this paper, the stratigraphic distribution of fusulinacean fauna in the Carboniferous-Permian boundary section at Xikou, Zhen’an County, Shaanxi Province, is analyzed quantitatively, and the relationship between the species diversity of fusulinaceans and relative sea-level changes is discussed. As a whole, the spe-cies numbers of fusulinacean fauna experience a rapid increase and an obvious decline in Xikou, Zhen’an County, from the Late Carboniferous to the Early Permian. There is a significant increase in species diversity around the Carboniferous-Permian boundary, which is one of the biggest bio-events of the fusulinacean fauna, and represents the radiation of Pseudoschwagerininae subfamily in the studied area. Integrated fusulinacean species diversity into sequence stratigraphic framework, de-tailed study suggests that the species diversity of the fusulinaceans is closely related to its relative stratigraphic location, and is essentially controlled by the sea-level changes, especially by the high-frequency sea-level changes. Generally, the species diversity of fusulinaceans is low, and the number of first and last appearance datum is small in the lower unit of high-frequency depositional cycle formed during the quick rise of the sea level; whereas the species diversity of fusulinaceans is high, and the number of first and last appearance datum is large in the upper unit of high-frequency cycle formed during the slow fall of the sea level. Within the third-order depositional sequence, the species diversity of the fusulinaceans at the first flooding surfaces and the maximum flooding surfaces is low, and it increases upward. The fusulinacean species diversity is low within the transgressive syst

关键词： fusulinaceans, species diversity, high-frequency cyclothem, sequence stratigraphy, sea-level changes, Carboniferous-Permian boundary, Zhen'an, Shaanxi.

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Liquid propellant analogy technique in dynamic modeling of launch vehicle

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Science china.Technological Sciences) 2010年第8期53卷 2102-2110页

作者： PAN ZhongWen 1,2.,XING YuFeng 1 ,ZHU LiWen 2.,DONG Kai 2.&SUN Mu 2.1Solid Mechanics research Center,beijing University of Aeronautics and Astronautics,beijing 100191,china.2.beijing Astronautics Systems Engineering institute,beijing 100076,china 1. Solid Mechanics research Center Beijing University of Aeronautics and Astronautics Beijing 100191 China2. Beijing Astronautics Systems Engineering Institute Beijing 100076 China

The coupling effects among lateral mode,longitudinal mode and torsional mode of a launch vehicle cannot be taken into account in traditional dynamic analysis using lateral beam model and longitudinal spring-mass model *** deal with the problem,propellant analogy methods based on beam model are proposed and coupled mass-matrix of liquid propellant is constructed through additional mass in the present *** an integrated model of launch vehicle for free vibration analysis is established,by which research on the interactions between longitudinal and lateral modes,longitudinal and torsional modes of the launch vehicle can be *** examples for tandem tanks validate the present method and its necessity.

关键词： dynamic characteristics coupled mass integrative modeling propellant analogy

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Compositions of heavy minerals in Northeastern china.sandlands and provenance analysis

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Science china.Earth Sciences 2007年第11期50卷 1715-1723页

作者： XIE Jing1,2.& DING ZhongLi1 1 institute of Geology and Geophysics, Chinese academy of Sciences, {2. 10002., china.2.Graduate University of Chinese academy of Sciences, {2. 100049, china 1. institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China 2. Graduate University of Chinese academy of Sciences Beijing 100049 China

Sand samples deposited since the Last Glacial Maximum (LGM) from the Hulun Buir, Horqin and Otin-dag sandlands were measured for their assemblages of heavy minerals and chemical compositions of detrital garnets and tourmalines. Heavy mineral assemblages of these three sandlands consist mainly of garnet, ilmenite, epidote and minor amphibole and magnetite. Garnets consist mainly of high Mg type-A ones (58% on average), and minor type-B ones. Toumalines are mainly composed of Mg-rich and minor Fe-rich ones. Compared with those of central-southern Mongolia and central Tarim, these three sandlands are derived from the Phanerozoic rocks of the Central Asian Orogenic Belt and the Archean and Paleoprotorozoic basement rocks of the North china.Craton. Our results provide direct evidence that the present-day sands may be reworked from LGM ones. Differences of heavy mineral composi-tions occur between the samples of the three sandlands and Taklimakan Desert, indicating that the material of the western arid regions contributes little to the eastern sandlands.

关键词： heavy minerals,provenance,Northeastern china.garnet,tourmaline

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Geological analysis and physical modeling of structural pumping in high effective formation of Kela 2.gas field

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Science china.Earth Sciences 2006年第10期49卷 1070-1078页

作者： ZHAO Wenzhi1, WANG Hongjun1, SHAN Jiazeng2. WANG Zecheng1 & XU Dafeng1 1. research institute of Petroleum Exploration and Development, Petro{2. beijing 100083, {2.2. institute of Geology and Geophysics, Chinese academy of Sciences, beijing 10002., china 1. research institute of Petroleum Exploration and Development Petrochina Beijing 100083 China 2. institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China

In a 3-D closed geological body, in case “structural expanding” inside is induced by stress, it can produce the pressure difference between the expanding cell and surrounding rock, then generate a pumping force directed toward the cell and accelerate the directional flow of fluid in the strata. The structural style and conditions of gas reservoir-formation in the Kuqa depression are favorable to the structural pumping. According to similarity principle, a physical modeling of structure formation and gas filling process of the Kela 2.gas field has justified the occurrence of structural pumping and its important role in gas-reservoir formation with high efficiency under the compressive and well-sealed circumstance. Therefore, authors propose that structural pumping is an important mechanism of gas reservoir-formation with high efficiency in the Kuqa depression.

关键词： Kela 2 gas field, structural pumping, gas-reservoir formation mechanism, high efficiency,physical modeling.

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Carbon isotope ratios of C_(4) plants in loess areas of North china

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Science china.Earth Sciences 2006年第1期49卷 97-102页

作者： WANG Guoan1,2.3, HAN Jiamao 2. ZHOU Liping3, XIONG Xiaogang4, TAN Ming2. WU Zhenhai5 & PENG Jun6 1. Department of Plant Nutrition, china.Agricultural University, beijing 100094, china.2. institute of Geology and Geophysics, Chinese academy of Sciences, beijing 10002., china.3. College of Environmental Sciences, MOE Laboratory for Earth Surface Processes, Peking University, beijing 100871, china.4. institute of Botany, Chinese academy of Sciences, beijing 100093, china.5. Northwest Sci-Tech University of Agriculture and forestry, Yangling 712.00, china.6. Network Center, china.Agricultural University, beijing 100094, china 1. Department of Plant Nutrition China Agricultural University Beijing 100094 China 2. institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China 3. College of Environmental Sciences MOE Laboratory for Earth Surface Processes Peking University Beijing 100871 China 4. institute of Botany Chinese Academy of Sciences Beijing 100093 China 5. Northwest Sci-Tech University of Agriculture and forestry Yangling 712100 China 6. Network Center China Agricultural University Beijing 100094 China

Carbon isotope ratios (δ^(13)C) of 89 C_4 plant samples were determined fromthe loess area in North china. δ^(13)C values vary between -10.5per thousand and -14.6per thousandwith a mean of -12.6per thousand. Along a precipitation gradient from the semi-moist area to thesemiarid area, then to the arid area, the δ^(13)C values of C_4 plants show a slight decreasingtrend. The δ^(13)C values of C_4 plants in the dry season are found lower than those in the wetseason. These trends are opposite to those observed for C_3 species.

关键词： C4 plants, carbon isotope ratios, loess area.

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