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chinese Science Bulletin 1998年第10期43卷 837-840页

作者： xu yigang {2. institute of Geochemistry, chinese academy of sciences, guangzhou 51064., china guangzhou institute of Geochemistry Chinese Academy of Sciences Guangzhou China

Spinel peridotite xenoliths from Wangqing, NE china exhibit correlative variations in texture, temperature, geochemistry and radiogenic isotopes. This suggests that the Wangqing xenoliths may come from a mantle diapir. It is possible that the fertile and undeformed lherzolites were situated in the interior of the diapir, whereas the refractory and deformed harzburgites and clinopyroxene_poor lherzolites were within the diapiric flanks.

关键词： peridotite xenoliths texture geochemistry Wangqing.

Summary of the 11th Conference on Magnetic Confined Fusion Theory and Simulation

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Plasma Science and Technology 2024年第10期26卷 1-7页

作者： guangzhou HAO Jianqiang xu Youwen SUN Zhibin GUO Organizing Committee of the 11th Conference on Magnetic Confined Fusion Theory and Simulation Southwestern institute of Physics Chengdu 610041People’s Republic of China institute of Plasma Physics Hefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031People’s Republic of China State Key Laboratory of Nuclear Physics and Technology Fusion Simulation CenterSchool of PhysicsPeking UniversityBeijing 100871People’s Republic of China 不详

This conference report summarizes recent progress in plasma theory and simulation that was presented in contributed papers and discussions at the 11th Conference on Magnetic Confined Fusion Theory and Simulation(CMCFTS)held in Chengdu,china,2.–30 October,*** in various fields has been *** example,results on zonal flow generation by mode coupling,simulations of the key physics of divertor detachment,energetic particle effects on magnetohydrodynamic(MHD)modes in addition to ion-and electron-scale turbulence,physics of edge coherent modes and edge-localized modes,and the optimization of ion heating schemes as well as confinement scenarios using advanced integrated modeling are presented at the *** this conference,the scientific research groups were organized into six categories:(a)edge and divertor physics;(b)impurity,heating,and current drive;(c)energetic particle physics;(d)turbulent transport;(e)MHD instability;and(f)integrated modeling and code development.A summary of the highlighted progress in these working groups is presented.

关键词： magnetic confined fusion(MCF) theory and simulation modeling tokamak

Trace element characteristics and origin of intergranular components in mantle peridotites

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chinese Science Bulletin 2000年第7期45卷 643-649页

作者： xu yigang{2. institute of Geochemistry, chinese academy of sciences, guangzhou 51064., china guangzhou institute of Geochemistry Chinese Academy of Sciences Guangzhou China

Leaching experiment has been carried out on mantle xenoliths with different petrographic features in order to directly characterize the nature of intergranular components. ICP-MS analyses of leachates show that they are characterized by high LREE concentrations with strong depletion of Ta. The total REE contents and whether the negative Rb, Ba and Nb anomalies are present or not in intergranular components are largely dependent upon the nature of mantle metasomatism experienced by its host rock. It is proposed that intergranular components may represent residues of small volume metasomatic melts.

关键词： peridotite xenoliths intergranular components trace elements upper mantle.

Scientific objectives and payload configuration of the Chang'E-7 mission

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National Science Review 2024年第2期11卷 285-300页

作者： Chi Wang Yingzhuo Jia Changbin xue Yangting Lin Jianzhong Liu Xiaohui Fu Lin xu Yun Huang Yufen Zhao {2. xu Rui Gao Yong Wei Yuhua Tang Dengyun Yu Yongliao Zou State Key Laboratory of Space Weather National Space Science Center Chinese Academy of Sciences National Space Science Center Chinese Academy of Sciences institute of Geology and Geophysics Chinese Academy of Sciences institute of Geochemistry Chinese Academy of Sciences Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment School of Space Science and Physics Institute of Space SciencesShandong University institute of Drug Discovery Technology Ningbo University State Key Laboratory of Isotope Geochemistry Guangzhou Institute of Geochemistry Chinese Academy of Sciences School of Earth Science and Engineering Sun Yat-sen University Lunar Exploration and Space Engineering Center china Aerospace Science and Technology Corporation

As the cornerstone mission of the fourth phase of the chinese Lunar Exploration Program, Chang'E-7(CE-7) was officially approved, and implementation started in 2.2., including a main probe and a communication relay satellite. The main probe, consisting of an orbiter, a lander, a rover and a mini-flying probe, is scheduled to be launched in 2.2.. The lander will land on Shackleton crater's illuminated rim near the lunar south pole, along with the rover and mini-flying probe. The relay satellite(named Queqiao-2. will be launched in February 2.2. as an independent mission to support relay communication during scientific exploration undertaken by Chang'E-4, the upcoming Chang'E-6 in 2.2. and subsequent lunar *** CE-7 mission is mainly aimed at scientific and resource exploration of the lunar south pole. We present CE-7's scientific objectives, the scientific payloads configuration and the main functions for each scientific payload with its key technical specifications.

关键词： Chang’ E-7 scientific objectives scientific payloads

Tree wavelet approximations with applications

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Science china Mathematics 2005年第5期48卷 680-702页

作者： xu Yuesheng & ZOU Qingsong Department of Mathematics, Syracuse University, Syracuse, NY 132.4, USA institute of Mathematics, {2. of Mathematics and System sciences, chinese academy of sciences, Beijing 100080, china Department of Scientific Computing and Computer Science, Zhongshan University, guangzhou 5102.5, china 1. Department of Mathematics Syracuse University 13244 Syracuse NY USA 2. institute of Mathematics Academy of Mathematics and System Sciences Chinese Academy of Sciences 100080 Beijing China 3. Department of Scientific Computing and Computer Science Zhongshan University 510275 Guangzhou China

We construct a tree wavelet approximation by using a constructive greedy scheme (CGS). We define a function class which contains the functions whose piecewise polynomial approximations generated by the CGS have a prescribed global convergence rate and establish embedding properties of this class. We provide sufficient conditions on a tree index set and on bi-orthogonal wavelet bases which ensure optimal order of convergence for the wavelet approximations encoded on the tree index set using the bi-orthogonal wavelet bases. We then show that if we use the tree index set associated with the partition generated by the CGS to encode a wavelet approximation, it gives optimal order of convergence.

关键词： greedy algorithms tree wavelet approximations Besov spaces.

Identification and analysis of shear waves recorded by three-component OBSs in northeastern South china Sea

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Progress in Natural Science:Materials International 2008年第2期18卷 181-188页

作者： Minghui Zhao ,xuelin Qiu,Shaohong Xia,Ping Wang,Kanyuan Xia,Huilong xu Key Laboratory of Marginal Sea Geology,South{2. Sea institute of Oceanology,chinese academy of sciences,guangzhou 510301,china Key Laboratory of Marginal Sea Geology South China Sea Institute of Oceanology Chinese Academy of Sciences Guangzhou 510301 China

Structure models associated with P-and S-wave velocities contain considerable amount of information on lithology and geophysical properties,which can be used to better understand the complexity of the deep crustal structure. However,records of converted shear waves are less due to the speciality of seismic survey at sea and the rigorous generated conditions. The study on shear waves has always been a weakness for studying the deep crustal structures of South china Sea (SCS). In this paper,eleven three-component OBSs were deployed along the Profile OBS-2.01 in northeastern SCS. After the data processing of polarization and band-pass filter,converted S-wave phases were identified in the radical component records of nine OBSs. Taking the OBS7 as an example,identification and analysis of converted shear waves were presented and discussed in detail. A few phase groups,such as PwSc,PgSs,PnSc,PmS,and PwSn,were found coming from the deep crust or Moho interface by simple theoretical model calculation and ray-tracing simulation. The results not only provide the underlying basis for studies of S-wave velocity structure and Poisson’s ratio structure,but also reveal the relationship between crustal petrology and seismology,which will be of importance for making full use of S-wave information in the future.

关键词： Converted shear wave Deep crustal structure Three-component ocean bottom seismometer Northeastern South china Sea

Distribution and identification of the low-velocity layer in the northern South china Sea

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Progress in Natural Science:Materials International 2007年第5期17卷 591-600页

作者： Zhao Minghui, Qiu xuelin, xu Huilong, Shi Xiaobin, Wu Shimin , Ye Chunming and Xia Shaohong (Key Laboratory of Marginal Sea Geology, South{2. Sea institute of Oceanology, chinese academy of sciences, guangzhou 510301,{2. Earthquake Administration of Guangdong Province, guangzhou 510070,{2.) [a]Key Laboratory of Marginal Sea Geology South China Sea Institute of Oceanology Chinese Academy of Sciences Guangzhou China [b]Earthquake Administration of Guangdong Province Guangzhou China

The low-velocity layer (LVL), closely related with tectonic activities and dynamic settings, has always been a hot topic in the deep crustal structure studies. The deep seismic (OBS/OBH) and onshore-offshore experiments have been extensively implemented in the northern South china Sea (SCS) since the 1990s. Six seismic profiles were finished on the northern margin of SCS by domestic and international cooperations. The features of crustal structures were revealed and five velocity-inversion layers were discovered. Among them three LVLs with 3.0—3. 5 km·s-1 velocity are located in the sedimentary structure (2.0—6.0 km in depth and 2.0—4. 6 km in thickness) of the Yinggehai Basin and Pearl River Mouth Basin. They were identified by the reflective and refractive phases for their shallow depth. The other two LVLs with 5.5—6.0 km·s-1 velocity generally existed in the middle crust (7.0—18.0 km in depth) with an about 2.5—6.0 km thickness in the transitional crustal structure of the northeastern and northwestern SCS. They were detected by the refractive phase from their overlain and underlying layers. We explored the possible tectonic formation mechanisms combining with previously reported results, which provided evidence for the formation and evolution of SCS.

关键词： low-velocity layer deep crustal structure the northern South china Sea OBS/OBH and onshore-offshore seismic experiments.

Controls on reservoir quality in the paleogene Kalatar Formation of the southwestern region of the Tarim Basin,china

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Petroleum Science 2011年第3期8卷 302-315页

作者： Yang Haijun Shen Jian-Wei Wang xu Zhang Lijuan Li Meng Key Laboratory of Marginal Sea Geology of CAS South China Sea Institute of Oceanology Chinese Academy of Sciences Guangzhou 510301 China Exploration and Development Research institute Tarim Oilfield Company Petroleum Company Limited Korla 841000 China Graduate School of the chinese academy of sciences Beijing 100049 China

The Paleogene Kalatar Formation is a main target for petroleum ex12. ploration in the southwestern region of the Tarim Basin （SWRTB） and a systematical summary of controls on reservoirs of high quality has important implications for this area. According to outcrop analysis, as well as core, and laboratory experiments based on theories of sedimentology, it can be inferred that the main pore types in the Kalatar Formation are moldic, vuggy, intercrystalline and interparticle pores, fractures, and mudstone microporosity, respectively. The foreshore in the shore-shelf depositional model is the most favorable target, wherein grainstone and dolomitized grainstone are characterized by high quality in a middle ramp subfacies of the carbonate ramp model. Diagenetic factors, such as micritization, cementation, compaction, neomorphism, silicification, and pyritization, are detrimental for reservoirs. At the same time, leaching and dolomitization can improve the quality of reservoirs. Permeability of reservoirs can be greatly improved by fractures, through which quality of reservoirs can be effectively enhanced. Concentration of CO2. temperature, and humidity are affected by changes in climate, which can have an influence on depositional setting, composition and diagenesis of sediments, and eventually the properties of reservoirs. The hot and arid climate of the Paleogene was harmful to development of reservoirs, which is demonstrated in the contemporaneous diagenetic and epigenetic stages. Shallow and deep-burial diagenesis are closely related to the formation and the connate water, however these are rarely affected by paleo-climatic variation. There is possible erosion that mainly resulted from organic acid in relative well intervals according to indications of hydrocarbons in the early diagenetic stage. Fracture systems can be established when acidic fluids are ernplaced during periods of uplift, by which pores can be effectively enlarged during the late diagenetic stages.

关键词： Kalatar Formation sedimentary facies diagenesis dolomitization fractures climaticconditions Tarirn Basin

Preliminary Response of Soil Fauna to Simulated N Deposition in Three Typical Subtropical Forests

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Pedosphere 2006年第5期16卷 596-601页

作者： xu Guo-Liang MO Jiang-Ming ZHOU Guo-Yi FU Sheng-Lei institute of Ecology South China Botanical Garden Chinese Academy of Sciences Guangzhou 510650 （China） Graduate School of the chinese academy of sciences Beijing 100039 （China）

A field-scale experiment arranged in a complete randomized block design with three N addition treatments including a control (no addition of N), a low N (5 g m-2.year-1), and a medium N (10 g m-2.year-1) was performed in each of the three typical forests, a pine (Pinus massoniana Lamb.) forest (PF), a pine-broadleaf mixed forest (MF) and a mature monsoon evergreen broadleaf forest (MEBF), of the Dinghushan Biosphere Reserve in subtropical china to study the response of soil fauna community to additions of N. Higher NH4+ and NO3- concentrations and a lower soil pH occurred in the medium N treatment of MEBF, whereas the NO3- concentration was the lowest in PF after the additions of N. The response of the density, group abundance and diversity index of soil fauna to addition of N varied with the forest type, and all these variables decreased with increasing N under MEBF but the trend was opposite under PF. The N treatments had no significant effects on these variables under MF. Compared with the control plots, the medium N treatment had significant negative effect on soil fauna under MEBF. The group abundance of soil fauna increased significantly with additions of higher N rates under PF. These results suggested that the response of soil fauna to N deposition varied with the forest type and N deposition rate, and soil N status is one of the important factors affecting the response of soil fauna to N deposition.

关键词： Dinghushan Biosphere Reserve N deposition soil fauna subtropical china

Regional patterns of particulate spectral absorption in the Pearl River estuary

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chinese Science Bulletin 2003年第21期48卷 2344-2351页

作者： CAO Wenxi, YANG Yuezhong, xu Xiaoqiang, HUANG Liangmin & ZHANG Jianlin LED Laboratory, South china Sea {2. of Oceanology, chinese academy of sciences, guangzhou 510301, china Correspondence should be addressed to Cao Wenxi (e-mail: wxcao@ ***) LED Laboratory South China Sea Institute of Oceanology Chinese Academy of Sciences Guangzhou China

Spectral absorption coefficients of the total particulate, ap(l ), nonalgal particulate, ad(l ), and phyto-plankton pigment, aph(l ), in the Pearl River estuary and its vicinity waters were determined using the quantitative filter technique. The particulate absorption ap(443) ranged from 0.04 to 1.82.m-1, with the corresponding aph(443) ranging from 0.016 to 0.484 m-1. Two typical spectral patterns are found for the total particulate absorption. For the first typi-cal spectral pattern, the total particulate absorption spectra are similar to that of nonalgal particulate, with values of absorption coefficient decreasing with wavelength. In con-trast, for the second spectral pattern the spectral absorptions by total particulate are very similar to that of phytoplankton pigment. The spectral dependency of absorption by nonalgal particulate follows an exponential increase toward short wavelengths, with an average slope of 0.012.0.002.nm-1. The nonalgal absorption and the fraction of the nonalgal particulate absorption to the total particulate absorption exhibit a distinct trend of decreasing with salinity of the sur-face water. Phytoplankton pigment absorption exhibits a clear trend of increasing nonlinearly with chlorophyll a con-centration. The relationships between the phytoplankton pigment absorption and chlorophyll a concentration can be described by power law, with the determination coefficient r2.of 0.82. But only weak relationships between ap(l ) and chlorophyll a concentration are observed, with the determination coefficient r2.of 0.42. The relatively large scatter around ap(443) versus chl-a relationship would be attributed to the effects of loading of the nonalgal particulate absorption. Our analysis indicated that such relationships similar to that for Case Ⅰ waters can be applicable to optically complex Case Ⅱ waters if the effects caused by nonalgal are corrected. The chlorophyll-specific absorption coefficients of phytoplankton pigment are not constant, it

关键词：光谱吸收系数浮游植物色素叶绿素珍珠河