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Problems of sequence stratigraphy in china

Journal of earth science 2000年第3期19卷 10-20页

作者： Wang Hongzhen Faculty of earth sciences and Mineral resources, china {3. of geosciences, beijing 100083. china

A comprehensive study of outcrop sequence stratigraphy in china began in the early 1990s. The investigated strata range from Mesoproterozoic to Quaternary and the studied areas cover the three platforms and margins, the southern Himalayas and the East china and south china seas. Problems of general concern in the sequence stratigraphy of china are discussed. These are: the hierarchy for sequence stratigraphy, the third order sequence and eustasy, the chronostratigraphic boundaries and GssP, and the International stratigraphic Chart and the sequence chronostratigraphy of china. The average time interval of Mesosequence (25-40 Ma) and of the sequence (2-5 Ma) is suggested and the minor sequences below the sequence are discussed. The time interval of the sequence shows no evident decrease with time, but several epochs with remarkable short intervals occur in the Phanerozoic, which may represent a planetary behavior denoting the special development stages in earth’s evolution. sea level change curves are given separately for the three platforms and the different regions. The Global stratotype section and Point (GssP) concept and practice are discussed, and a comparison between the first appearance point of biozone and the first flooding surface in the sequence is made for designation of the chronostratigraphic boundary. It is suggested that the chronostratigraphic boundaries might be set at the first flooding surface in the sequence for easy recognition. The idea of sequence chronostratigraphy is recommended, and a comparison between the International stratigraphic Chart and the sequence chronostratigraphy of china is made. The close relation between chronostratigraphy and sequence stratigraphy makes it possible for sequence stratigraphy to improve chronostratigraphic research. It is pointed out that multidisciplinary study in chronostratigraphy is necessary and should be promising and profitable.

关键词： sequence stratigraphy chronostratigraphy GssP china.

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surface characteristics of rapidly solidified nickel-based superalloy pow-ders prepared by PREP

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Rare Metals 2003年第4期22卷 309-314页

作者： CHEN Huanming , HU Benfu , and LI Huiying1) school of Materials science and Engineering, university of science and Technology beijing,{3.2) school of Physics and Electrical Information Engineering, Ningxia university, Yinchuan 750021, china school of Materials science and Engineering University of Science and Technology Beijing Beijing 100083 Chins

The surface microstructure and the surface segregation of FGH 95 nickel-basedsuperalloy powders prepared through plasma rotating electrode processing (PREP) have beeninvestigated by using sEM and AEs. The results indicate that the surface microstructure of powderschanges from dendrite into cellular stricture as the particle size of powders decrease, and thepredominant precipitates solidified on the particle surfaces were identified as MC' type carbidesenriched with Nb and Ti. It was also indicated that along with the depth of particle surfaces, thesegregation layer of s, C and O elements are thick, and that of Ti, Cr elements are thin for largesire powders while they are in reverse for median size particles.

关键词： FGH 95 nickel-based superalloy powders surface characteristics microstructure plasma rotating electrode processing

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3. Integrated geological Modeling in Tongshan Copper Deposit,Heilongjiang Province,china

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地学前缘 2009年第S1期16卷 282-283页

作者： Gongwen Wang,Limei Wang,Ge Cui,Chengyin Tan,shanyan Jin school of earth sciences and resources,{3. university of geosciences(beijing),beijing 100083.{3..

In this paper,3.-GIs reconstruction and interpolation approach,additional virtual borehole technology and BP network technology are used to explore the concealed ore *** virtual borehole has same function as reality b... 详细信息

关键词： 3. geological modeling virtual borehole BP network mineral exploration Tongshan copper deposit

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stability on Finite Time interval andTime-Dependent Bifurcation Analysis ofDuffing's Equations

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Communications in Nonlinear science and Numerical simulation 1999年第4期4卷 268-271页

作者： Cuncai HUA Qishan LU(school of science, beijing university of Aeronautics and Astronautics, beijing 100083.china) school of science Beijing Univ. Aero. and Astronaut. Beijing 100083 China

IntroductionInPhysics,MechanicsandEngineering,ChemistryandLifescienceetc.,thereealstbfforcationproblemsm***etimepassingthrought... 详细信息

IntroductionInPhysics,MechanicsandEngineering,ChemistryandLifescienceetc.,thereealstbfforcationproblemsm***etimepassingthrought...

关键词： stability on finite time interval time-dependent bifurcation Duffing’s equa-tion

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Dynamic mechanisms of the post-seismic deformation following large events:Case study of the 1999 Chi-Chi earthquake in Taiwan of china

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science china earth sciences 2009年第11期52卷 1813-1824页

作者： ZHU shouBiao1,2 & CAI YongEn2 1 Institute of Crustal Dynamics, china earthquake Administration, beijing 100085, china 2 Department of geophysics, Peking university, beijing 100871, china 1. Institute of Crustal Dynamics China Earthquake Administration Beijing 100085 China 2. Department of geophysics Peking University Beijing 100871 China

The mechanism of postseismic deformation related to strong earthquakes is important in geodynamics, and presumably afterslip or viscoelastic relaxation is responsible for the postsesimic deformation. The 1999 Chi-Chi, Taiwan of china, earthquake occurred in the region where GPs observation station is most densely deployed in the world. The unprecedented GPs data provides a unique opportunity to study the physical processes of postseismic deformation. Here we assume that the interactions of viscoelastic relaxation, afterslip, fault zone collapse, poroelastic rebound, flow of underground fluids, and all these combined contribute to the surface displacements following the main shock. In order to know the essence of the postseismic deformation after the strong event, fault zone collapse, poroelastic rebound, flow of underground fluids, and so on, are represented equivalently by the variations of the focal medium properties. Therefore, the viscoelastic relaxation, afterslip, and the variations of the equivalent focal medium properties are inverted by applying the GPs temporal series measurement data with viscoelastic finite element method. Both the afterslip rate distribution along the fault and the afterslip evolution with time are obtained by means of inversion. Also, the preliminary result suggests that viscosities of the lower crust and the upper mantle in Taiwan region is 2.7×1018 and 4.2×1020 Pa·s, respectively. Moreover, the inversion results indicate that the afterslip contributing to postseismic deformation of 44.6% in 450 days after the Chi-Chi earthquake, with 3..7% caused by the viscous relaxation and 20.7% by other factors such as fault zone collapse, poroelastic rebound, and the flow of liquids.

关键词： mechanism of postseismic deformation viscoelastic finite element method GPs temporal series data Chi-Chi earthquake

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Ultramafic xenoliths in Mesozoic diorite in west shandong Province

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science china earth sciences 2004年第6期47卷 489-499页

作者： CHEN Lihui1,2 & ZHOU Xinhua2 1.The Key Laboratory of Orogenic Belts and Crustal Evolution,Ministry of Education,china and school of earth and space sciences,Peking {3.,beijing 100871,china 2.Institute of geology and geophysics,Chinese Academy of sciences,beijing 100029,china Correspondence should be addressed to Chen Lihui(email: lihui_chen@***) 1. The Key Laboratory of Orogenic Belts and Crustal Evolution Ministry of Education China and School of Earth and Space Science Peking University 100871 Beijing China 2. Institute of geology and geophysics Chinese Academy of Sciences 100029 Beijing China

Ultramafic xenoliths are common in Tietonggou intrusion, Laiwu, shandong Prov-ince. Peridotite xenoliths develop two-stage metasomatism popularly: (i) The early metasoma-tism is characterized by intergranular clinopyroxene and phlogopite; (ii) The later metasomatism is characterized by orthopyroxene veins with a few plagioclases and amphiboles. These ul-tramafic xenoliths are thought to be mostly from the crust-mantle transitional zone on the basis of their combination, mineral chemistry, equilibrium temperature, and metasomatic characteristics. Major elements, rare earth elements, and sr-Nd isotopic composition of the ultramafic xenoliths indicate that there is a petrogenetic relationship between the silica-enriched xenoliths and their host diorites. We propose that such silica enrichment might be an indicator of melt-rock interac-tions in the Mesozoic lithosphere beneath western shandong.

关键词： ultramafic xenoliths, crust-mantle transitional zone,metasomatism, Tietonggou intrusion, Laiwu.

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Electron surfing acceleration in a current sheet of flares

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science china(Physics,Mechanics & Astronomy) 2009年第11期52卷 1810-1812页

作者： WANG DeYu1 & LU QuanMing2 1 Purple Mountain Observatory, Nanjing 210008, china 2 school of earth and space sciences, {3. of science and Technology of china, Hefei 23.026, china Purple Mountain Observatory Nanjing 210008 China school of earth and space sciences University of Science and Technology of China Hefei 230026 China

A model of electron acceleration in a current sheet of flares is studied by the analytical approximation solution and the test particle simulation. The electron can be trapped in a potential of propagating electrostatic wave. The trapped electron moving with the phase velocity v p of wave may be effectively accelerated by ev p/c × B z force along the outflow direction in the current sheet, if a criterion condition K > 0 for electron surfing acceleration is satisfied. The electron will be accelerated continuously until the electron de-trap from the wave potential at the turning point s.

关键词： electron acceleration electrostatic wave current sheet

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The feature study on the π and proton rapidity distributions at AGs, sPs and RHIC

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science china(Physics,Mechanics & Astronomy) 2009年第2期52卷 198-206页

作者： FENG shengQin1,2 & YUAN XianBao1,3.1 College of science, china Three Gorges university, Yichang 443.02, china 2 {3. of Physics and Technology, Wuhan university, Wuhan 43.072, china 3.Institute of Particle Physics, Central china Normal university, Wuhan 43.070, china 1. College of science China Three Gorges University Yichang 443002 China 2. school of Physics and Technology Wuhan University Wuhan 430072 China 3. Institute of Particle Physics Central China Normal University Wuhan 430070 China

The features of nuclear stopping power and multi-hadron production systematically are studied by making an analysis of rapidity distributions of pion and proton at AGs, sPs and RHIC in this work. It is found that nuclear stopping power increases linearly with project rapidity yp at AGs and sPs, but that is not liner at RHIC. It is argued that the average rapidity loss is saturated at central rapidity region at RHIC. For pion distribution, it is found that the phase space of pion distribution distributes uniformly in the longitudinal direction,and a linear relationship of L with log s is given at AGs and sPs. Non-uniform flow model may explain the features of the distribution at AGs and sPs, but may not ex- plain those of at RHIC.

关键词： non-uniform flow model average rapidity loss baryon number density nuclear stopping power

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An application of the Riemann-Roch theorem

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science china Mathematics 2008年第4期51卷 765-772页

作者： WANG shiKun~1 ZHANG HuiPing~(2+) 1 KLMM and IAM AMss Chinese Academy of sciences beijing 100080 china 2 school of Information Renmin {3. of china beijing 100872 china 1. KLMM and IAM AMSS Chinese Academy of Sciences Beijing 100080 China 2. school of Information Renmin University of China Beijing 100872 China

Applying the Riemann-Roch theorem,we calculate the dimension of a kind of mero- morphicλ-differentials’ space on compact Riemann *** we also construct a basis of theλ-differentials’ *** the main result,the Cauchy ... 详细信息

关键词： Riemann-Roch theorem λ-differential annulus domain Cauchy integral formula 14C40

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Effect of upward ion on field-aligned currents in the near-earth magnetotail

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science china(Physics,Mechanics & Astronomy) 2007年第5期50卷 673-680页

作者： ZHANG LingQian1, LIU ZhenXing1, MA ZhiWei2, sHEN Chao1, ZHOU XuZhi3.& ZHANG XianGuo3.1 Center for space and Applied Research, Chinese Academy of sciences, beijing 100080, china 2 Institute of Plasma Physics, Chinese Academy of sciences, Hefei 23.03., china 3.{3. of earth and space science, Peking university, beijing 100871, china 1. Center for space and Applied Research Chinese Academy of Sciences Beijing 100080 China 2. Institute of Plasma Physics Chinese Academy of Sciences Hefei 230031 China 3. school of earth and space science Peking University Beijing 100871 China

A 3.dimensional resistive MHD simulation was carried out to study the effect of the upward ions on the field-aligned currents (FACs) in the near-earth magnetotail. The simulation results show that the up-flow ions originating from the nightside auroral oval would drift into the center plasma sheet along the magnetic field lines in the plasma sheet boundary, and have an important effect on the field-aligned currents. The main conclusions include that: 1) the upward-ions mainly affect the field- aligned currents in the near-earth magnetotail (inside 15 Re); 2) the generated FACs in the near-earth region have two types, i.e., Region 1 FAC in the high-latitude and Region 2 FAC in the low-latitude; 3. FACs increase with the enhancement of the upward ion flux; 4) with the same flux of the upward ions, FACs enhance with the increase of the velocity of the up-flow ions; 5) the intensification of FACs is also closely related with the latitude of the upward ions, and the ions from the closed field line region generate larger FACs; 6) the generation of FACs is closely related with By created by the upward ions.

关键词： up-flow ions, near-earth magnetotail, field-aligned current

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