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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, {3. 100083. china 2. Key Laboratory of Oil and Gas Reservoir of Petro{2., {3. 100083. china 3. china university of Geosciences, {3. 100083. china 4. Institute of Geology, china Earthquake Administration, {3. 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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Response synchronization: New progress in brain-visual information processing

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chinese Science Bulletin 1999年第16期44卷 1447-1458页

作者： ZHAO Songnian, XIONG Xiaoyun, YAO Guozheng and GUO Aike1. State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry , Institute of Atmospheric Physics , chinese academy of Sciences , {2. 10002.,{4. 2. Commission of the National Natural Science Foundation of{4. , {2. 100083.{4. 3. The Center of Information Science , Peking university, {2. 100871,{4. 4. Open Laboratory of Visual Information Processing , Institute of Biophysics , chinese academy of Sciences , {2. 100101,{4. State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China Commission of the National Natural Science Foundation of china Beijing China The Center of Information Science Peking University Beijing China Open Laboratory of Visual Information Processing Institute of Biophysics Chinese Academy of Sciences Beijing China

Studies on brain-vision have entered a new stage, after the stimulus-induced y synchronized oscillation of neuron group activities have been discovered in cat primary visual cortex. Naturally, how to understand the visual system became a very important methodological problem. From aspects such as information processing, nonlinear dynamics and neuronal network, some primary problems in vision studies have been deeply discussed, which are

关键词： neuron group (neural population) synchro-oscillation computational theory of vision response synchroniza-tion.

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Evaluation of Sustainable Land Management and Diagnosis of Obstacle at County Scale in Sichuan Basin:Taking Lezhi County as Example

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Wuhan university Journal of Natural Sciences 2006年第4期11卷 1046-1051页

作者： CHEN Guangjian 1, 2. 3., LIU Qing 1 1. Chengdu Institute of Biology, chinese academy of Sciences, Chengdu 6100{3., Sichuan,{2. 2. Graduate university of chinese academy of Sciences, beijing 1000{3., china 3. academy of Land Reconnaissance and Layout of Sichuan Province , Chengdu 61003., Sichuan, china Chengdu Institute of Biology Chinese Academy of Sciences Chengdu Sichuan China Graduate university of chinese {2. of Sciences Beijing China academy of Land Reconnaissance and Layout of Sichuan Province Chengdu Sichuan China

This paper established sustainable land resources evaluating indicators fit for hilly area in Sichuan Basin, Southwest of china, and evaluated the case of sustainable land management of Lezhi County from 1990 to 2.01. The result showed that the land resource sustainable utilization ability in Lezhi County is belong to Second level （better sustainable）. Secondly, this paper diagnosed some years obstacles of sustainable land management of Lezhi County from base period to goal period and compared the obstacles factors in the indicators system. There were 16 indexes orderly become major affect factor to land sustainable utilization of Lezhi county in indicator system, of which there are 8 obstacles indexes exist both in 1990 and 2.01. The value of obstacles degree of five indicators exceeded 5 in 1990, but in 2.01, only two indicators＇ values were more than 5.

关键词： land resources sustainable land management assessment indicators diagnosis of obstacle

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A mixed method for measuring low-frequency acoustic properties of macromolecular materials

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Science china(Physics,Mechanics & Astronomy) 2006年第6期49卷 729-739页

作者： LIU Hongwei1,YAO Lei1,3.ZHAO Hong1,3.ZHANG Jichuan2.3.& XUE Zhaohong2.1. National Key Laboratory of Acoustics,Institute of Acoustics,chinese {3. of Sciences,{2. 100080,china 2. Institute of Chemistry,chinese {3. of Sciences,{2. 100080,china 3. Graduate university of chinese {3. of Sciences,{2. 10004.,china National Key Laboratory of Acoustics Institute of Acoustics Chinese Academy of Sciences Beijing 100080 China Institute of Chemistry Chinese Academy of Sciences Beijing 100080 China Graduate university of chinese {2. of Sciences Beijing 100049 China

A mixed method for measuring low-frequency acoustic properties of macro-molecular materials is presented. The dynamic mechanical parameters of materials are first measured by using Dynamic Mechanical Thermal Apparatus(DMTA) at low frequen-cies,usually less than 100 Hz; then based on the Principles of Time-Temperature Super-position (TTS),these parameters are extended to the frequency range that acousticians are concerned about,usually from hundreds to thousands of hertz; finally the extended dynamic mechanical parameters are transformed into acoustic parameters with the help of acoustic measurement and inverse analysis. To test the feasibility and accuracy,we measure a kind of rubber sample in DMTA and acquire the basic acoustic parameters of the sample by using this method. While applying the basic parameters to calculating characteristics of the sample in acoustic pipe,a reasonable agreement of sound absorp-tion coefficients is obtained between the calculations and measurements in the acoustic pipe.

关键词： low-frequency acoustic properties,dynamic mechanical properties,Principles of Time-Temperature Superposition,acoustic pipe,sound absorption coefficient.

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Monitoring the Cultivated Slope Land in the Three Gorges Reservoir Area Based on Remote Sensing and GIS

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Wuhan university Journal of Natural Sciences 2006年第4期11卷 915-921页

作者： ZHOU Jieming1, ZHOU Qigang 2. 3.,HUANG Zhiqin 2. 3. 4.1. The Faculty of Geography and Resources Science, Sichuan Normal {3., Chengdu 610066, Sichuan, china 2. Institute of Mountain Hazards and Environment, {2. academy of Sciences, Chengdu 61004., Sichuan, china 3. Graduate {3. of the {2. academy of Sciences, {13. 10004., china 4. Information Center of Land and Resources Department of Sichuan Province, Chengdu 61004., Sichuan, china The Faculty of Geography Resources Science Sichuan Normal University 610066 Chengdu Sichuan China Institute of Mountain Hazards Environment Chinese Academy of Sciences 610041 Chengdu Sichuan China Graduate university of the chinese {2. of Sciences 100049 Beijing China Information Center of Land Resources Department of Sichuan Province 610041 Chengdu Sichuan China

By means of combining auto-extraction with manual interpretation, the current distribution information about cultivated land is obtained. The distribution information of 1992.is extracted from the dynamic polygons of 2.02. The monitoring mini-system of the cultivated slope land is established. In the system, detailed surveys, focused on the resources of cultivated slope land, are carried out. The results indicate that the area of the cultivated slope land is very large. Meanwhile, there are lots of cultivated steep slopes with gradient above 3.°. The areas of steep land cultivated had been slowly reduced from 1992.to 2.02. At the same time, the pressures of returning farm land to forestry are great in all counties. The conflicts between population growth, insufficient grain supply and stagnant economic development sharpen increasingly. It is inevitable to improve the agricultural structure.

关键词： slope land cultivated remote sensing geography information system (GIS) the pressure of returning farm land to forestry Three Gorges Reservoir Area

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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 {4., {2. 100094. china 2. Institute of Geology and Geophysics, chinese academy of Sciences, {2. 10002., china 3. College of Environmental Sciences, MOE Laboratory for Earth Surface Processes, Peking {4., {2. 100871, china 4. Institute of Botany, chinese academy of Sciences, {2. 100093. china 5. Northwest Sci-Tech {4. of Agriculture and Forestry, Yangling 712.00, china 6. Network Center, china Agricultural {4., {2. 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 -1{3.6per 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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Two possible mechanisms for vortex self-organization

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Science china Earth Sciences 2006年第2期49卷 202-211页

作者： LUO Zhexian2. ZHOU Xiuji1 & GAO Shouting3.1. chinese academy of Meteorological Sciences, {2. 100081,{4. 2. Department of Space Information Science, Nanjing university of Information Science and Technology, Nanjing 2.004.,{4. 3. Institute of Atmospheric Physics, chinese academy of Sciences, {2. 10002.,{4. 2. Department of Environmental Science Nanjing University of Information Science and Technology Nanjing 210044 China 1. chinese academy of Meteorological Sciences Beijing 100081 China 3. Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

The vortex self-organization is investigated in this paper by four groups of numerical experiments within the framework of quasi-geostrophic model, and based on the experimental results two types of possible mechanisms for vortex self-organization are suggested. The meso-scale to-pography may enable separated vortices to merge into a larger scale vortex; and the interaction of meso-γ and meso-β scale systems may make separated vortices to self organize a typhoon-like vor-tex circulation.

关键词： vortex, self-organization, meso-scale topography, interaction of different scales.

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Geochemical simulation of the formation of brine and salt minerals based on Pitzer model in Caka Salt Lake

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Science china Earth Sciences 2004年第8期47卷 720-726页

作者： LIU Xingqi1, CAI Keqin2.& YU Shengsong3.1. Nanjing Institute of Geography and Limnology, chinese academy of Sciences, Nanjing 2.0008,{2. 2.{2. university of Geosciences, beijing 100083.{2. 3. Institute of Salt Lakes, chinese academy of Sciences, Xining 810008,{2. 1. Nanjing Institute of Geography and Limnology Chinese Academy of Sciences 210008 Nanjing China 2. china university of Geosciences 100083 Beijing China 3. Institute of Salt Lakes Chinese Academy of Sciences 810008 Xining China

The geochemical simulation of the formation of brine and salt minerals based on Pitzer model was made in Caka Salt Lake. The evolution of the mixed surface-water and the mineral sequences were calculated and compared with the hydrochemical compositions of the brine and the salt minerals of the deposit in Caka Salt Lake. The results show that the formation temperature of the lake is between 0°C and 5°C, which is well identical with other studies. The mixing of salt-karst water with the surface waters, neglected by the former researchers, is very important to the formation of the lake, indicating that the initial waters resulting in the formation of the lake are multi-source. It is the first time to use Pitzer model in china for making geochemical simulation of the formation and evolution of inland salt lake and satisfactory results have been achieved.

关键词： Pitzer model,Caka Salt Lake,geochemical simulation,salt-karst water.

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Time of impact of fragment P2.of comet SL 9 on Jupiter

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chinese Science Bulletin 1997年第5期42卷 396-398页

作者： ZHOU Hongnan,QIAN Bochen, HUANG Keliang and LI Qibin1. Department of Astronomy, Nanjing university, Nanjing 2.0093. china 2. Shanghai Observatory, {2. academy of Sciences, Shanghai 2.003., china 3. Physics Department, Nanjing Normal university, Nanjing 2.0097, china 4. beijing Astronomical Observatory, {2. academy of Sciences, beijing 100080, china Department of Astronomy Nanjing University Nanjing China Shanghai Observatory Chinese Academy of Sciences Shanghai China Physics Department Nanjing Normal University Nanjing China beijing Astronomical Observatory Chinese Academy of Sciences Behijing China

FROM 1994.07-16 to 1994.07-2., 2. fragments of comet SL 9 impacted against Jupiter in succession. During the impact period the impact of fragments D, E, K, N, P2.and S was observed in china. We used a 1.56-m telescope with the CCD camera of Shanghai Observatory to monitor Jupiter and its Galilean Satellites, obtaining 1000 high-quality images at B, V, I wave bands. Our data on optical wave bands are rather complete and valuable in the world. Specially, we got some images of Jupiter, Io and Europa in the impact time of fragment P2.impacting against Jupiter. This will help us understand the precise time, position, depth and energy of the P2.s collision. In this note, we report the impact time of fragment P2.of comet SL 9 and Jupiter. Since the impact of comet SL 9 was expected to take place on the side of Jupiter

关键词： comet comet Shoemaker-Levy 9 impacting against Jupiter impact time.

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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 5702.6,{3. 2. Institute of Geomechanics, {4. {2. of Geological Sciences, beijing 100081,{3. 3. beijing Center of SHRIMP, beijing 10003.,{3. 4. Institute of Geology, {4. {2. of Geological Sciences, beijing 10003.,{3. 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 2.6Pb/2.8U ages of 3.8±3.5 Ma (of granite, 95% confidence level, MSDW=1.2.) and 3.2.9±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.

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