检索结果-南通市图书馆

Re-Os isotopic system and formation age of subcontinental lithosphere mantle

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2000年第3期45卷 193-200页

作者： ZHI XiachenDepartment of earth and Space sciences, {2. of Science and technology of china, Hefei 2.002., china Advance research center for earth Science and astronomy, USTC, third world {12. of Science, Hefei 2.002., china Laboratory of Chemical Geodynamics, USTC, Hefei 2.002., china Department of earth and Space sciences University of Science and Technology of China Hefei China Advance research center for {2. Science and astronomy USTC Third World Academy of Science Hefei China Laboratory of Chemical Geodynamics USTC Hefei China

The determination of the formation age of subcontinental Lithosphere Mantle (SCLM) is a widely concerned issue in mantle geochemistry. it is difficult to obtain the formation age of SCLM using lithophile isotopic systems such as Rb-Sr, Sm-Nd, U-Th-Pb, ete., but as siderophile elements, the Re-Os isotopic system provides a powerful tool for that work. Here a comprehensive review on the recent development in Re-Os dating for SCLM has been given.

关键词： Re-Os isotopic dating subcontinental lithospheric mantle mantle derived peridotites Re depleted model age whole rock isochronological age.

Observation results of relativistic electrons detected by Fengyun-1 satellite and analysis of relativistic electron enhancement (REE) events

在线全文

学校读者我要写书评

暂无评论

Science china(Physics,Mechanics & astronomy) 2008年第12期51卷 1947-1956页

作者： YANG XiaoChao1,2. & WANG ShiJin1 1 center for Space Science and Applied research, Chinese {2. of sciences, Beijing 100190, china 2.Graduate university of Chinese {2. of sciences, Beijing 100049, china 1. center for Space Science and Applied research Chinese Academy of Sciences Beijing 100190 China 2. Graduate university of Chinese academy of {2. Beijing 100049 China

The space particle component detector on Fengyun-1 satellite which works at the sun-synchronous orbit of about 870 km altitude has detected relativistic electrons for a long time. In comparison with the SAMPEX satellite observations during 1999–2.04, the relativistic electron data from Fengyun-1 satellite from June 1999 to 2.05 are used to analyze the relativistic electron enhancement (REE) events at the low earth orbit, and the possible correlation among REE events at the low earth orbit, high-speed solar wind and geomagnetic storms is discussed. The statistical result presents that 45 REE events are found in total during this time period, and the strong REE events with the maximum daily average flux > 400 cm?2.srt-1·s?1 occur mostly during the transition period from solar maximum to solar minimum. Among these 45 REE events, four strong REE events last a longer time period from 2.-to 51-day and correlate closely with high speed solar wind and strong geomagnetic storms. Meanwhile, several strong geomagnetic storms occur continuously before these REE events, and these continuous geomagnetic storms would be an important factor causing these long-lasting strong REE events. The correlation analysis for overall 45 events indicates that the strength of the REE events correlates with the solar wind speed and the strength of the geomagnetic storm, and the correlation for strong REE events is much stronger than that for weak REE events.

关键词： relativistic electron enhancement low earth orbit high-speed solar wind geomagnetic storm

research of the Gas-solid Flow Character Based on the DEM Method

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2011年第6期20卷 521-526页

作者： Xueyao Wang and Yunhan Xiao research center for Clean Energy and Power,Chinese {2. of sciences Key Laboratory of advanced Energy and Power,Chinese {2. of sciences (Institute of Engineering Thermophysics),Beijing,100190,china research center for Clean Energy and Power Chinese Academy of Sciences Beijing China Key Laboratory of advanced Energy and Power Chinese Academy of Sciences (Institute of Engineering Thermophysics) Beijing China

Numerical simulation of gas-solid flow behaviors in a rectangular fluidized bed is carried out three dimensionally by the discrete element method (DEM).Euler method and Lagrange method are employed to deal with the gas phase and solid phase *** collided force among particles,striking force between particle and wall,drag force,gravity,Magnus lift force and Saffman lift force are considered when establishing the mathematic ***-sphere model is used to describe the collision of *** addition,the Euler method is also used for modeling the solid phase to compare with the results of *** flow patterns,particle mean velocities,particles' diffusion and pressure drop of the bed under typical operating conditions are *** results show that the DEM method can describe the detailed information among particles,while the Euler-Euler method cannot capture the micro-scale *** matter which method is used,the diffusion of particles increases with the increase of gas *** the gathering and crushing of particles cannot be simulated,so the energy loss of particles' collision cannot be calculated and the diffusion by using the Euler-Euler method is *** addition,it is shown by DEM method,with strengthening of the carrying capacity,more and more particles can be schlepped upward and the dense suspension upflow pattern can be ***,the results given by the Euler-Euler method are not consistent with the real situation.

关键词： DEM gas-solid flow numerical simulation

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

在线全文

学校读者我要写书评

暂无评论

Science china earth {2. 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, {2. 2. Laboratory for earth Material Cycling, School of earth and Space sciences, university of Science and technology of {2., Hefei 2.002., {2. 3. Institute of Mineral Resource, Chinese academy of Geological sciences, Beijing 100037, {2. National research center of Geoanalysis Beijing {2. Laboratory for earth Material Cycling School of Earth and Space Sciences University of Science and Technology of China Hefei China Institute of Mineral Resource Chinese academy of Geological sciences Beijing {2.

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 0.2.9 ± 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 82. ± 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.

Interannual variability of Antarctic Oscillation and its influence on East Asian climate during boreal winter and spring

在线全文

学校读者我要写书评

暂无评论

Science china earth {2. 2006年第5期49卷 554-560页

作者： FAN Ke1,2.3 & WANG Huijun2.1. Nansen-Zhu International research center, Institute of Atmospheric Physics, Chinese {2. of sciences, Beijing 10002., china 2. Department of Atmospheric Science, Yunnan university, Kunming 650091, china 3. Graduate university of the Chinese {2. of sciences, Beijing 100049, china 1. Nansen-Zhu International research center Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China 2. Department of Atmospheric Science Yunnan University Kunming 650091 China 3. Graduate university of the Chinese academy of {2. Beijing 100049 China

The interannual variability of Antarctic Oscillation (AAO) and its influence on East Asian climate during both boreal winter and spring are addressed. The results show that the positive AAO anomaly decreases the cold activity over East Asia during both boreal winter and spring. AAO-related barotropic meridional teleconnection from Antarctic to Arctic is found through analysis of mean me- ridional circulations. This meridional teleconnection is remarkable over Eurasia during boreal winter and over the Pacific Ocean during boreal spring. The results also show that zonal mean zonal wind at high latitudes in Southern Hemisphere has well positive correlation with that of Eurasia during boreal winter and has negative correlation with Pacific North American teleconnection (PNA) during boreal spring, which again display the meridional teleconnection. Thus, local meridional teleconnection is a possible linkage for interaction of circulations at mid-high latitudes between both hemispheres.

关键词： Antarctic Oscillation, Eurasian west wind, meridional teleconnection, mean meridional circulation.

A new iguanodontid (Jin-zhousaurus yangi *** ***.) from the Yixian Formation of western Liaoning,china

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2001年第19期46卷 1669-1672页

作者： WANG Xiaolin & XU Xing1. Institute of Vertebrate Paleontology and Paleoanthropology, Chinese academy of sciences, Beijing 100044, {2. 2. College of earth sciences and Resources, {2. university of Geo-sciences, Beijing 100083, {2. Institute of Vertebrate Paleontology and Paleoanthropology Chinese Academy of Sciences Beijing China College of earth sciences and Resources China University of Geosciences Beijing China

A new iguanodontid, Jinzhousaurus yangi gen. et sp. nov., is erected based on the cranial and dental morphology of a specimen from the Yixian Formation of western Liaoning. Although a few primitive characteristics remain, Jinzhousaurus yangi display a number of characteristics similar to those seen in derived iguanodontids. Other interesting characteristics include the absence of antorbital fenestra and the frontal excluded from the participation in orbit, which are closer to the condition in hadrosaurids. The unusual combination of the characteristics provides important data for assessing morphological evolution toward hadrosaurs. The new discovery also represents the first reported large-sized dinosaur from Jehol fauna in western Liaoning, and increases the diversity of this famous fauna. Furthermore, the discovery of a derived iguanodontid from the Yixian Formation provides further evidence supporting a Cretaceous age of the Jehol fauna, which is consistent with an isotopic age.

关键词： Western Liaoning Lower Cretaceous Yixian Formation Jehol Biota Iguanodontid

Regional differences and determinants of built-up area expansion in china

在线全文

学校读者我要写书评

暂无评论

Science china earth {2. 2007年第12期50卷 1835-1843页

作者： HUANG JiKun1,2.ZHU LiFen3,1 & DENG XiangZheng1,2.1 center for Chinese Agricultural Policy,Chinese academy of {2.,Beijing 100101,china 2.Institute of Geographic {2. and Natural Resources research,Chinese academy of {2.,Beijing 100101,china 3 research center of the Economy of the Upper Reaches of the Yangtze River,Chongqing technology and Business {12.,Chongqing 400067,china 1. center for Chinese Agricultural Policy Chinese Academy of Sciences Beijing 100101 China 2. Institute of Geographic sciences and Natural Resources research Chinese Academy of Sciences Beijing 100101 China 3. research center of the Economy of the Upper Reaches of the Yangtze River Chongqing Technology and Business University Chongqing 400067 China

Based on remote sensing data on land use provided by the Chinese academy of sciences and socio-economic data collected by the authors,this paper analyzes the trends and regional differences in built-up area(BUA) expansion in {2. from the late 1980s to 2.00,and empirically estimates the major determinants of BUA expansion in different regions in 1996―*** 1989―2.00,although {2.'s overall BUA expansion accelerated,the trends differed significantly among *** expansion in the central and western regions accelerated significantly,but it slowed down considerably in the east-ern *** estimation results from our econometric analysis reveal that BUA expansion in the eastern region reached a period when economic growth had no further significant impact on per capita BUA,the land utilization in this region has become more intensive with further expansion of the *** the central and western regions,the BUA has expanded remarkably due to the relatively more flexible land development policies and the relatively cheap land ***,as the econ-omy continues to grow rapidly,policies relating to BUA expansion and cultivated land reductions may face more serious challenges in the central and western regions.

关键词： built-up area, land use, regional difference, determinants, china

Explanation of the mechanism of carcinogenesis and syntheses of anticancer agents with high selectivity

在线全文

学校读者我要写书评

暂无评论

Science china Chemistry 2006年第1期49卷 44-62页

作者： DAI Qianhuan1,2.1. center of Chemistry and Bioengineering of Cancer research, Beijing Polytechnic {2. (Now known as Beijing Univer-sity of technology), Beijing 10002., china 2. center of Environmental sciences, Peking {2., Beijing 100871, china 1. center of Chemistry and Bioengineering of Cancer research Beijing Polytechnic University Beijing 100022 China 2. center of Environmental sciences Peking University Beijing 100871 China

In 1979, the mechanism of chemical carcinogenesis, a challenging anddifficult scientific problem pending for a number of years, was explained by Dai Qianhuan. Themechanism named di-region theory predicted that a carcinogen always metabolizes to form a specialbi-functional alky-lating agent. This agent induces cross-linkages between the complementary basepairs in DMA and switches on initial mutageneses in genomes including point and frameshiftmutations. This, in turn, induces further deep mutageneses including the production of variouschimeric chromosomes, deletions and other aberrations found in genomes. In the end this initiatescarcinogenesis of the whole cell through the reverse transcription mechanism after a lengthyincubation period. Recently, this laboratory has verified that physical carcinogenesis, includingthe oncogenesis induced by radiation and asbestos as well as the carcinogenesis induced byendogenous factors such as estrogen or diethyl-stilbestrol switch on carcinogenesis by inducing theformation of cross-linkages between the complementary base pairs in DNA. Di-region theory has nowbeen supported by many experimental observations such as mutational spectra of various *** potential for carcinogenesis, teratogenesis, sterility and mutagenesis lumped together asgenetic toxicity appears to originate almost uniformly from the cross-linking between complementarybases, i.e. malignant cross-linking, which is in accordance with di-region theory. Other forms ofcross-linking between non-complementary bases, benign cross-linkings, show bi-functional alkylationanticancer activity but lack genetic toxicity. The predictable design and synthesis of a highselectivity anticancer agent with high efficacy and low genetic toxicity, a goal long pursued incancer chemotherapy, have been realized for the first time in this laboratory by inhibitingmalignant and heightening benign cross-linking using the principles of di-region theory. A series ofpatented new anticanc

关键词： mechanism of carcinogenesis, di-region theory, minoplatin, selectivity of anticancer agent, cross-linking between DNA bases, anticancer platinum complexes, predictive design of anticancer agent, second generation anticancer agent.

Adsorption of zinc on manganite(γ-MnOOH): particle concentration effect and adsorption reversibility

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental sciences 2004年第4期16卷 627-630页

作者： QIN Yan-wen1, PAN Gang 1,2., ZHANG Ming-ming1, LI Xian-liang1 (1. State Key Laboratory of Environmental Aquatic Chemistry, research center for Eco-Environmental {2., Chinese academy of {2., Beijing 100085, china. 2. Qingdao university of Science & technology, Qingdao 2.6042. china) State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China.

The adsorption and desorption processes of Zn(Ⅱ) on γ-MnOOH as a function of particle concentrations(C p) were studied. An obvious C p effect was observed in this adsorption system. The degree of adsorption hysteresis increased greatly with the increasing of C p, indicating that the extent of the real metastable-equilibrium states deviating from the ideal equilibrium state was enhanced with the increasing of C p. The C p-reversibility relationship confirmed the metastable-equilibrium adsorption(MEA) inequality(Pan, 1998a), which was the core formulation of the MEA theory. Because the MEA inequality was based on the basic hypothesis of MEA theory that adsorption density Γ is not a state variable, the C p-reversibility relationship gave indirect evidence to the basic hypothesis of MEA theory.

关键词： zinc γ-MnOOH adsorption reversibility