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Genesis of ^(2.0)Th excess in basalts from mid-ocean ridges and ocean islands:Constraints from the global U-series isotope database and major and rare earth element geochemistry

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Science china Earth sciences 2010年第10期53卷 1486-1494页

作者： zhang GuoLiang1,2.& ZENG ZhiGang1 1 Key Laboratory of Marine Geology and Environment,institute of Oceanology,{2. academy of sciences,Qingdao 2.6071,china 2.Graduate University of chinese academy of sciences,Beijing 100049,china 1. Key Laboratory of Marine Geology and Environment Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China2. Graduate University of Chinese Academy of Sciences Beijing 100049 China

Based on 2.0Th-2.8U disequilibrium and major element data from mid-ocean ridge basalts(MORBs) and ocean island basalts(OIBs),this study calculates mantle melting parameters,and thereby investigates the origin of 2.0Th excess.(2.0Th/2.8U) in global MORBs shows a positive correlation with Fe8,Po,Na8,and Fmelt(Fe8 and Na8 are FeO and Na2. contents respectively after correction for crustal fractionation relative to MgO = 8 wt%,Po=pressure of initial melting and Fmelt=degree of melt),while 2.0Th excess in OIBs has no obvious correlation with either initial mantle melting depth or the average degree of mantle ***,compared with the MORBs,higher(2.0Th/2.8U) in OIBs actually corresponds to a lower melting *** suggests that the 2.0Th excess in MORBs is controlled by mantle melting conditions,while the 2.0Th excess in OIBs is more likely related to the deep garnet *** vast majority of calculated initial melting pressures of MORBs with excess 2.0Th are between 1.0 and 2.5 GPa,which is consistent with the conclusion from experiments in recent years that DU>DTh for Al-clinopyroxene at pressures of >1.0 *** initial melting pressure of OIBs is 2.2.3.5 GPa(around the spinel-garnet transition zone),with their low excess 2.6Ra compared to MORBs also suggesting a deeper mantle ***,excess 2.0Th in MORBs and OIBs may be formed respectively in the spinel and garnet stability *** addition,there is no obvious correlation of K2./TiO2.with(2.0Th/2.8U) and initial melting pressure(Po) of MORBs,so it is proposed that the melting depth producing excess 2.0Th does not tap the spinel-garnet transition *** and MORBs in both(2.0Th/2.8U) vs.K2./TiO2.and(2.0Th/2.8U) *** plots fall in two distinct areas,indicating that the mineral phases which dominate their excess 2.0Th are ***/Yb-Ce curves of fast and slow ridge MORBs are similar,while,in comparison,the Ce/Yb-Ce curve for OIBs shows more influence from *** mechanism

关键词： excess 2.0Th clinopyroxene garnet spinel-lherzolite mid-ocean ridge ocean island

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Terrestrial transect study on driving mechanism of vegetation changes

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Science china Earth sciences 2008年第7期51卷 984-991页

作者： zhang YuJin1,2.& ZHOU GuangSheng1 1 State Key Laboratory of Vegetation and Environmental Change, institute of Botany,{2., Beijing 100093, china 2.Graduate University of{2., Beijing 100049, china 1. State Key Laboratory of Vegetation and Environmental Change Institute of Botany Chinese Academy of Sciences Beijing 100093 China 2. Graduate University of chinese academy of sciences Beijing 100049 China

In terms of chinese climate-vegetation model based on the classification of plant functional types, to- gether with climatic data from 1951 to 1980 and two future climatic scenarios (SRES-A2.and SRES-B2. in china from the highest and the lowest emission scenarios of greenhouse gases, the distribution patterns of vegetation types and their changes along the Northeast china Transect (NECT) and the North-South Transect of Eastern china (NSTEC) were simulated in order to understand the driving mechanisms of vegetation changes under climatic change. The results indicated that the vegetation distribution patterns would change significantly under future climate, and the major factors driving the vegetation changes were water and heat. However, the responses of various vegetation types to the changes in water and heat factors were obviously different. The vegetation changes were more sensi- tive to heat factors than to water factors. Thus, in the future climate warming will significantly affect vegetation distribution patterns.

关键词： driving mechanism vegetation terrestrial transect climatic change plant functional types

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The three-dimensional structure and seasonal variation of the North Pacific meridional overturning circulation

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Acta Oceanologica Sinica 2011年第3期30卷 33-42页

作者： LIU Hongwei zhang Qilong DUAN Yongliang HOU Yijun institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China Key Laboratory of Ocean Circulation and Waves （KLOCAW） Chinese Academy of Sciences Qingdao 266071 China The Graduate School of the chinese academy of sciences Beijing 100049 China

The three-dimensional structure and the seasonal variation of the North Pacific meridional overturning circulation （NPMOC） are analyzed based on the Simple Ocean Data Assimilation data and Argo profiling float data. The NPMOC displays a multi-cell structure with four cells in the North Pacific altogether. The TC and the STC are a strong clockwise meridional cell in the low latitude ocean and a weaker clockwise meridional cell between 7°N and 18°N, respectively, while the DTC and the subpolar cell are a weaker anticlockwise meridional cell between 3°N and 15°N and a weakest anticlockwise meridional cell between 35°N and 50°N, respectively. The DTC, the TC and the STC are all of very strong seasonal variations. As to the DTC, the southward transport is strongest in fall and weakest in spring. For the TC, the northward transport is strongest in winter and weakest in spring, while the southward transport is strongest in fall and weakest in spring, which is associated with the strong southward fiow of the DTC in fall. As the STC, the northward transport is strongest in winter and weakest in summer, while the southward transport is strongest in summer and weakest in spring. This seasonal difference may be associated with the DTC. The zonal wind stress and the east-west slope of sea level play important roles in the seasonal variations of the TC, the STC and the DTC.

关键词： North Pacific meridional overturning circulation three-dimensional structure seasonal variation

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New technique to control in situ oxygen fugacity in water-free high-pressure system──Using Cu-O as an example

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chinese Science Bulletin 1998年第16期43卷 1353-1358页

作者： LI Heping 1, XIE Hongsen 1, GUO Jie 1, zhang Yueming 1,XU Zuming 1 and XU Ji’an 2.1. institute of Geochemistry,{2., Guiyang 550002. china 2. institute of Earth sciences, Taiwan 1152., china institute of Geochemistry Chinese Academy of Sciences Guiyang China institute of Earth sciences Taiwan China

Through inserting a solid oxygen-specific electrolyte (YSZ) inside and exerting an electrical power of direct current outside between the sample and oxygen reservoir (an solid oxygen buffer), oxygen was driven by the power from the cathodic electrode area into the positive electrode area at high temperature and high pressure. In this way, the oxygen fugacity in the sample was in situ controlled independently of temperature and pressure. By using Cu-O system as an example, this technique was proved to be successful.

关键词： in situ control of oxygen fugacity water-free system high temperature and high pressure.

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The role of reservoir mediums in natural oil cracking:Preliminary experimental results in a confined system

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chinese Science Bulletin 2010年第33期55卷 3787-3793页

作者： XIAO QiLin1,2.SUN YongGe1,3 & zhang YongDong1,2.1 State Key Laboratory of Organic Geochemistry,Guangzhou institute of Geochemistry,{2. academy of sciences,Guangzhou 510640,china 2.Graduate Schools,{2. academy of sciences,Beijing 100049,china 3 institute of Environmental and Biogeochemistry(eBig),Zhejiang University,Hangzhou 31002.,china State Key Laboratory of Organic Geochemistry Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 China Graduate Schools Chinese Academy of Sciences Beijing 100049 China institute of Environmental and Biogeochemistry (eBig) Zhejiang University Hangzhou 310027 China

Large amounts of data regarding the influence of temperature and pressure on the thermal stability of crude oil have been pub-lished;however,the role of reservoir mediums has received little *** involving oil cracking in the presence of montmorillonite,illite,calcite,quartz and water were conducted in closed gold tubes to investigate the effects of these reservoir mediums on oil *** was done by screening variations in the chemical and stable carbon isotopic components of nC10+ and gasoline-range hydrocarbons(nC8-)present in various *** indicated that reservoir mediums have an active role in oil cracking under experimental *** concentrations of nC10+ in the cracked residues progressively decreased in systems containing oil+water+illite,oil+water+montmorillonite,oil+water,oil+water+quartz and oil+water+*** comparison with the system containing oil+water,our results indicated a retardation effect for oil cracking in systems in the presence of illite and montmorillonite,and an acceleration effect on oil destruction in systems in the presence of calcite and ***10+ became increasingly depleted in 13C in systems with oil+water+illite,oil+water+calcite,oil+water+montmorillonite,oil+water+ quartz and oil+*** obvious correlation was observed between concentrations and stable carbon isotopic components of nC6-nC8 and nC10+ in the individual *** discrepancies in chemical and stable carbon isotopic components of nC6-nC8 and nC10+ in the pyrolyzed residues highlighted the important role of reservoir mediums to control carbon-carbon cleavage of nC10+ and then the isomerization,cyclolization and aromatization reactions;as well as governing the occurrence and thermal destruction of nC6-nC8 under experimental *** research may have critical implications in reconstructing chemical kinetic models for natural oil cracking.

关键词：裂解作用实验条件密闭系统原油裂解水库介质天然同位素组成

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Experimental and discrete element numerical analysis of side slope instability induced by fissure water underlying impervious bed

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Science china(Technological sciences) 2005年第z1期48卷 65-80页

作者： LIU Bingshan1, LI Shihai1, zhang Lei1,2.& WANG Jianguo31. institute of Mechanics,{2., Beijing 100080, china 2. Graduate School,{2., Beijing 100060, china 3. Tropical Marine Science institute, National University of Singapore, 10 Kent Ridge Crescent, Singapore 1192.0 chinese Acad Sci Inst Mech Beijing 100080 Peoples R China chinese Acad Sci Grad Sch Beijing 100060 Peoples R China Natl Univ Singapore Trop Marine Sci Inst Singapore 119260 Singapore

When the sliding mass contains impervious bed, rainfall can infiltrate into mountain via crevices and form higher artesian aquifer at impervious bed inferior. This will decrease slip resistance and increase sliding forces of the sliding mass, thus lowering the safety factor, and inducing landslide disasters. In this paper, a landslide experimental apparatus is designed for experimental studies on the mechanism of this type of landslides. Meanwhile, the non-dimensional parameters in the model experiment are taken into account using dimensional analysis. The experimental results show that (1) the ratio of the cleft water pressure to the overlying pressure is a crucial parameter affecting the stability of the slope; (2. when the shut-in pressure reaches 80% of the normal component of the pressure on the slip surface made up of rock and soil, landslide will occur; (3) the whole slope will start to slide when the shut-in pressure is equal to the normal component of the pressure formed by the overlying rock and soil on the upper 30% area. In this article, a discrete element method simulation is used to investigate the influence of cleft water pressure and shearing strength on the landslide stability. It can be concluded that the critical value of Ccr, ?cr, which determines the slide mass stability, increases with the increase of the water pressure; if the water pressure reaches a high level, the stability of the slide mass depends mainly on C, while the influence of ? becomes smaller than C.

关键词： impervious bed, rainfall infiltration, pore water pressure, landslide experiment, displacement monitor, discrete element method.

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Oxidative cyclization of allyl compounds and isocyanide: A facile entry to polysubstituted 2.cyanopyrroles

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chinese Chemical Letters 2024年第4期35卷 330-335页

作者： yaping zhang Wei Zhou Mingchun Gao Tianqi Liu Bingxin Liu Chang-Hua Ding Bin Xu Department of Chemistry Affiliated Nantong Hospital of Shanghai University(The Sixth People's Hospital of Nantong)Shanghai Engineering Research Center of Organ RepairInnovative Drug Research CenterSchool of MedicineShanghai UniversityShanghai 200444China State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China

A facile Tf OH-catalyzed oxidative cyclization of allyl compounds and isocyanide has been developed with the assistance of DDQ, where isocyanide is used as the crucial "N" and "CN" sources. Highly functionalized 2.cyanopyrroles are constructed efficiently through a new formal [3 + 2. mode, demonstrating diverse reactivity and synthetic utility in organic chemistry. 2.Cyanopyrrole is converted into a nucleobase analogue of Remdesivir and 5H-pyrrolo[2.1-a]isoindole through a three-step or a two-step sequence, respectively. This protocol features broad substrate scope, operational simplicity and good functional group tolerance.

关键词： Isocyanide Cyanopyrrole Insertion Allyl compound Bronsted acid catalysis

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Pollen limitation and variation in floral longevity in gynodioecious Potentilla tanacetifolia

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Journal of Systematics and Evolution 2011年第6期49卷 539-545页

作者： 1,2.ong yao 1Yi-Bo LUO 1(State Key Laboratory of Systematic and Evolutionary Botany,institute of Botany,{2. {2. of sciences,Beijing 100093,china) 2.Graduate University of the chinese academy of sciences,Beijing 100049,china) (State Key Laboratory of Systematic and Evolutionary Botany Institute of Botany Chinese Academy of Sciences Beijing 100093 China) (Graduate University of the chinese academy of sciences Beijing 100049 China) *Correspondence: Yi-Bo LUO *Correspondence: E-mail: luoyb@*** Tel.: 86-10-62.36514 Fax: 86-10-62.90843.

Pollination limitation is common in flowering plants and is thought to be a factor driving the evolution of floral *** plasticity of floral longevity to pollination may be an adaptation of plants to pollen ***,this adaptation is less critical in short-lived *** evaluate pollen limitation and the plasticity of floral longevity to pollination in Potentilla tanacetifolia,a gynodioecious herb with short-lived flowers,we analyzed its breeding system,tested sex-differential pollen limitation,and compared variations in floral display size in natural populations in Duolun County,Inner Mongolia,*** pollination experiments and pollinator exclusion treatments revealed that *** is self-compatible and non-autonomously apomictic and shows sex-differential pollen *** plasticity of floral longevity to pollination was observed;the floral duration of female plants was prolonged by approximately 3-4 hours with pollination exclusion ***,the percentage of flowers displayed on female plants during pollination exclusion treatment was significantly higher than that during natural *** natural pollination conditions,the percentage of flowers displayed on female plants was significantly higher than on hermaphrodite ***,approximately 50%of the pollen grains spread out of the anthers of hermaphrodite flowers within 2.h of anthesis;the number of pollen grains adhering to the stigmas of hermaphrodite flowers was significantly higher than that adhering to female flowers when flowers shed their *** results indicate that variation in floral longevity may be an adaptive strategy to pollination conditions for gynodioecious ***.

关键词： floral longevity gynodioecy plasticity pollen limitation Potentilla tanacetifolia.

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A NEW STYRYL-LACTONE COMPOUND FROMGONIOTHALAMUS LEIOCARPUS

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chinese Chemical Letters 1996年第7期7卷 617-618页

作者： Qing MU Chao Ming LI Hong Jie zhang Yu WU and Han Dong SUN(kunming {2. of Botany, chinese academy of sciences,kunming 6502.4) chinese ACAD SCI KUNMING INST BOTKUNMING 650204PEOPLES R CHINA

A new styryl-lactone compound, named as leiocarpin A (1), was isolated from Goniothalamus leiocarpus. Its structure and relative configuration were determined by means of spectrum particularly 2. NMR including H-1-H-1...

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Influence factors of sparse microwave imaging radar system performance:approaches to waveform design and platform motion analysis

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Science china(Information sciences) 2012年第10期55卷 2301-2317页

作者： zhang Zhe 1,2.3,zhang BingChen 1,2.JIANG ChengLong 1,2.3,XIANG Yin 1,2.HONG Wen 1,2.& WU YiRong 1,2.1 Science and Technology on Microwave Imaging Laboratory,Beijing 100190,{2. 2.institute of Electronics,chinese academy of sciences,Beijing 100190,{2. 3 Graduate University,chinese academy of sciences,Beijing 100190,{2. 1. Science and Technology on Microwave Imaging Laboratory Beijing 100190 China 2. institute of Electronics Chinese Academy of Sciences Beijing 100190 China 3. Graduate University Chinese Academy of Sciences Beijing 100190 China

Sparse microwave imaging radar is a newly developed concept of microwave imaging system,which tries to combine the traditional radar imaging system with sparse signal processing theories,achieving the aim of reducing the complexity of microwave imaging systems and enhancing the system *** this paper,we introduce some basic concepts of sparse signal processing theory,and then apply it to the traditional radar imaging system to get the mathematical model of sparse microwave imaging *** analyze the factors that determine the performance of sparse microwave imaging radar,including scene,waveform and *** to the radar model,we analyze how these factors influence the radar system and how to optimize *** results of the sparse microwave imaging radar system are also provided.

关键词： sparse microwave imaging radar synthetic aperture radar compressive sensing Lq regularization waveform design

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