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The evolution and morphological stability of a spherical crystal

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Science china(Technological sciences) 2008年第3期51卷 225-243页

作者： CHEN MingWen1,2. WANG ZiDong2.& XU JianJun3.4 1 school of Applied {2., university of Science and Technology Beijing, Beijing {3. china 2.school of Materials Science and Engineering, university of Science and Technology Beijing, Beijing {3. china 3.school of Mathematical {2., Nankai university, Tianjin 3.0071, china 4 Department of Mathematics and Statistics, McGill university, Montreal H3. 2.6, Canada 1. school of Applied sciences University of Science and Technology Beijing Beijing 100083 China 2. school of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China 3. school of Mathematical {2. Nankai University Tianjin 300071 China 4. Department of Mathematics and Statistics McGill University Montreal H3A 2K6 Canada

The growth model of a spherical crystal in the undercooled melt including the surface energy, interfacial kinetics and convective flow is established. The effect of the convective flow induced by a small far field flow on the evolution and morphological stability of the interface of the spherical crystal is studied. The interface shape of the spherical crystal, which is affected by the far field flow, and the dispersion relation of the growth rate of amplitude of the perturbed interface are derived. It is shown that the convection induced by the far field flow makes the interface of the growing spherical crystal further grow in the upstream direction of the far field flow and inhibit growth in the downstream direction; the interface of the decaying spherical crystal further decays in the upstream direction and inhibits decay in the downstream direction. The theoretical result suggests that both the growth of the sphere in the upstream direction and the decay of the sphere in the downstream direction make the spherical crystal tend to evolve into an oval; the morphological stability of the interface depends on a certain radius R c such that the spherical crystal is unstable when its radius is greater than R c and stable when its radius is less than R c . The surface energy and interfacial kinetics have strong stabilizing effects on the growth of the spherical crystal. In the meantime interfacial kinetics is a table factor of the interface when the interface of the sphere is growing; it is an unstable factor of the interface when the interface is decaying.

关键词： solid-liquid interface spherical crystal convective flow crystal growth morphological stability

Two conceptual models of displacement transfer and examples

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Science china earth {2. 2005年第7期48卷 900-911页

作者： GUAN Shuwei1,2. WANG Xin2. YANG Shufeng2. HE Dengfa1 & ZHAO Weidong3.1. Research Institute of Petroleum Exploration and Development, Beijing 100083. {2. 2. Department of geosciences, Zhejiang {3., Hangzhou 3.002., {2. 3. Tarim Oilfield Company, Korla 841000, {2. Research Institute of Petroleum Exploration and Development Beijing 100083 China Department of geosciences Zhejiang University Hangzhou 310027 China Tarim Oilfield Company Korla 841000 China

This paper presents two conceptual models of displacement transfer, reverse sym- metry model and infinitely equal division model, based on the fault-bend folding theory. If the fault shape is held constant in the trend, then the distribution of slip magnitude, geometry of imbricate structures and its axial surface map all display reverse symmetry on the process of displacement transfer, as called reverse symmetry model in this paper. However, if the ramp height of thrust fault decreases gradually along its strike, the displacement is postulated to be equally and infinitely divided to every thrust that is formed subsequently, this kinematic process is described using infinitely equal division model. In both models, displacement transfer is characterized by the regular changes of imbricate thrusting in the trend. Geometric analysis indicates that the displacement transfer grads can be estimated using the tangent of deflective angle of hinterland structures. Displacement transfer is often responsible for the distortion and branching of the surface anticlines, especially in the region where the multi-level detachment structures is developed. We also present some examples from the frontal structures of the Southern Tianshan fold-and-thrust belt, Xinjiang, china. Displacement transfer between deep imbricate thrusts in the middle segment of Qiulitag anticline zone causes the Kuqatawu and Southern Qiulitag deep an- ticlines left-lateral echelon. The region, where these two deep anticlines overlap, is characterized by duplex structures, and extends about 18 km. The shallow anticline is migrated southward displaying obvious “S” form in this area.

关键词： displacement transfer fault-bend folding reverse symmetry model infinitely equal division model Qiulitag zone.

A new Early Cretaceous lizard with well-preserved scale impressions from western Liaoning, china

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Progress in Natural Science:Materials International 2005年第2期15卷 67-73页

作者： JI Shu’an*(school of earth and Space {2., Peking {3., Beijing 100871, china) school of earth and Space {2. Peking University Beijing 100871 China

A new small lizard, Liaoningolacerta brevirostra gen. et sp. nov., from the Early Cretaceous Yixian Formation of western Liaoning is described in detail. The new specimen was preserved not only by the skeleton, but also by the exceptionally clear scale impressions. This lizard can be included within the taxon Scleroglossa based on its 2. or more presacrals, cruciform interclavicle with a large anterior process, moderately elongated pubis, and slightly notched distal end of tibia. The scales vary evidently in size and shape at different parts of body: small and rhomboid ventral scales, tiny and round limb scales, and large and longitudinally rectangular caudal scales that constitute the caudal whorls. This new finding provides us with more information on the lepidosis of the Mesozoic lizards.

关键词： new genus Squamata skeleton lepidosis Early Cretaceous western Liaoning

Macro-and microscopic mechanical behaviour of flow of coal samples experimentally deformed at high temperatures and pressures

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Chinese Science Bulletin 2005年第S1期50卷 59-66页

作者： LIU Junlai , YANG Guang & MA Rui State Key Laboratory of Geological Processes and Mineral resources, china university of geosciences, Beijing {2. {3. Key Laboratory of Lithosphere Tectonics and Lithoprobing Technology of Ministry of Education, china university of geosciences, Beijing {2. {3. College of earth sciences, Jilin university, Changchun 13.061, {3. china Univ Geosci State Key Lab Geol Proc & Mineral Resources Beijing 100083 Peoples R China china Univ Geosci Minist Educ Key Lab Lithosphere Tecton & Lithoprobing Technol Beijing 100083 Peoples R China Jilin Univ Coll Earth Sci Changchun 130061 Peoples R China

Coal samples from Qinshui Basin, Shanxi, china are experimentally deformed at temperatures and confining pressures of 2.0 - 500℃and 2.0 - 500 Mpa, strain rate of 0.5×10-5/s and total strain of 10%. The vitrinite reflectance of the coal samples varies from 3.04 to 1.79. It is shown that the strengths of the deformed samples change obviously with coeval increasing temperatures and pressures (T/P). At the experimental range of T/P, the effects of increasing temperature predominate over that of increasing pressure. Microstructural analysis indicates a brittle to ductile transition under experimental T/P conditions from 2.0 to 3.0℃, and 2.0 to 3.0Mpa. Brittle deformation microstruc-tures include macroscopic fracture zones and penetrative fracture associations. Elongation, undulose or irregular extinction, deformation lamellae and dynamic recrystallization of grains are the main ductile deformation microstructures. The variation of deformation mechanisms of the experimentally deformed coal samples is related to both the components of coals and T/P conditions. At low T/P, fractures occur in both inertinite and vitrinite of the samples. At higher T/P, crystalline plastic deformations are observed in the inertinite only.

关键词： coal experimental deformation brittle to ductile transition.

New lower bounds of classical Ramsey numbers R(6,12., R(6,14) and R(6,15)

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Chinese Science Bulletin 1998年第10期43卷 817-818页

作者： LUO Haipeng 1, SU Wenlong 2.and LI Qiao 3.1. Guangxi Academy of sciences, Nanning 53.03., china 2. Wuzhou First Middle school, Wuzhou 543.02. china 3. Shanghai Jiaotong university, Shanghai 2.003., china Guangxi Academy of sciences Nanning China Wuzhou First Middle school Wuzhou China Shanghai Jiaotong university Shanghai China

Three new cyclic graphs are constructed by using a computer, and the lower bounds of three Ramsey numbers obtained: R(6,12.≥2.4, R(6,14)≥2.8,R(6,15)≥3.8, which fill in three blanks in the table of bounds of Ram... 详细信息

关键词： Ramsey number lower bound cyclic graph.

Identification of Hercynian shoshonitic intrusive rocks in central Hainan Island and its geotectonic implications

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Science Bulletin 2006年第20期51卷 2507-2519页

作者： XIE Caifu1, 2. ZHU Jinchu1, DING Shijiang3. ZHANG Yeming2. FU Tai’an2.& LI Zhihong2.1. State Key Laboratory for Mineral Deposits Research and Department of earth {2., Nanjing university, Nanjing 2.0093. {3. 2. Yichang Institute of Geology and Mineral resources, Yichang 443.03. {3. 3. Hainan Bureau of Geology and Mineral resources, Haikou 5702.6, {3. Department of Otolaryngology University Hospital VU P.O. Box 7057 1007 MB Amsterdam The Netherlands State Key Laboratory for Mineral Deposits Research and Department of earth sciences Nanjing University Nanjing 210093 China

An identification has been made of some shoshonitic intrusive rocks in central Hainan Island recently. These rocks are K-rich (K2.=2.9%―5.1%, K2./Na2.=0.95―2.12., distinctly enriched in LILE and LREE, strongly depleted in Nb, Ta, and moder- ately depleted in Sr and Ti, with (87Sr/86Sr)i = 0.70859―0.7142. and ε Nd(t) = (?2.77―?7.49). They were derived from an EMⅡ-type mantle source. The enrichment process is related to metasomatism of depleted mantle caused by a great amount of fluid-melt released from oceanic crust and terri- genous sediments at great depth (eclogite facies) during the subduction of the South china plate under the Indochina-South china Sea plate in the Carbon- iferous–Early Permian. A SHRIMP U-Pb zircon dating yields a crystallization age of 2.2.7 Ma for the sho- shonitic intrusions, which is coeval with the strongly peraluminous granites found in central Hainan Island. These two kinds of rocks generally possess syn-intrusion ductile deformation structures. Thus they are considered to have been generated during the early stage (syn-thrust phase) of a post-collisional event. The primary magma of shoshonitic rocks was produced at a depth > 80 km by decompression- dehydration melting of previously enriched litho- spheric mantle wedge, phlogopite-bearing garnet peridotite, which was in turn caused by the break-off of a descendent slab and upwelling of a hot as- thenosphere. The rising of melts was accompaniedby crustal contamination and crystallization fractiona- tion (AFC). Combining with other related data, it is proposed that the southwards subduction and amal- gamation of the South china plate with the Indo- china-South china Sea plate took place at ca. 2.7- 2.8 Ma, which was a part of the convergence proc- ess of the Pangea supercontinent. The suture zone was probably located along the line of Song Ma-Beibu Gulf-north margin of the Yunkai Moun- tains-Wuyi Mountains.

关键词： SHRIMP U-Pb dating Hercynian shoshonitic intrusive rocks post-collisional event enriched mantle Hainan Island.

Zircon LA-ICPMS study and petrogenesis simulation of Dahuabei pluton in the Wulashan area,Inner Mongolia

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Progress in Natural Science:Materials International 2009年第12期19卷 1727-1737页

作者： Dapeng Li~(a,b),Yuelong Chen~(a,*),Liemeng Chen~c,Zhong Wang~d,Jinbao Liu~d a school of earth {2. and {3.,china university of geosciences(Beijing),Beijing 100083.china b State Key Laboratory of Geological Process and Mineral {3.,china university of geosciences,Wuhan 43.074,china c State Key Laboratory of Ore Deposit Geochemistry,Institute of Geochemistry,Chinese Academy of {2.,Guiyang 550002.china d Geological Survey Institute of Inner Mongolia,Hohhot 010010,china [a]school of earth {2. and {3. China University of Geosciences (Beijing) Beijing 100083 China [b]State Key Laboratory of Geological Process and Mineral resources China University of Geosciences Wuhan 430074 China [c]State Key Laboratory of Ore Deposit Geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China [d]Geological Survey Institute of Inner Mongolia Hohhot 010010 China

Dahuabei pluton in the Wulashan area,Inner Mongolia,is an alkaline and peraluminous granitic ***-ICPMS U-Pb dating of zircons indicates that this pluton crystallized at 3.0±10 *** pluton did not experience apparent zircon *** consistent temperatures between Zr saturation(765℃) and the average zircon-rutile Ti equilibrium(780℃),together with zircon ages and their CL images,indicated that there were no inherited zircons in this *** the simulation of the dry-system crystallization process of magma cooling at 2.0 MPa and 1100-709℃,the phase diagram and composition evolution tendency of different phases were *** magma reached its liquidus at 1069℃.Sanidine was the first crystallized phase;at 709℃the residual magma was less than 4%,and the range of 1069-719℃should be the most suitable approach to the real *** is shown that at least some part of the pluton underwent such isobaric equilibrium crystallization processes during its crystallization.

关键词： Dahuabei pluton Petrogenesis simulation Geochemistry Zircon LA-ICPMS

Effective solutions to a global 3. visual system in networking environments

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Science china earth {2. 2005年第11期48卷 2032-2039页

作者： ZHANG Liqiang1,2. ZHANG Yan3. YANG Chongjun2. LIU Suhong1, REN Yingchao2. RUI Xiaoping2.& LIU Donglin2.1. State Key Laboratory of Remote Sensing sciences, {2. of Geography and Remote Sensing, Beijing Normal university, Beijing 100875, {3. 2. State Key Laboratory of Remote Sensing sciences, Institute of Remote Sensing Applications, Chinese Academy of sciences, Beijing 101001, {3. 3. Institute of Geographical sciences and Natural resources Research, Chinese Academy of sciences, Beijing 101001, {3. 1. State Key Laboratory of Remote Sensing sciences School of Geography and Remote Sensing Beijing Normal University 100875 Beijing China 2. Chinese Academy of sciences State Key Laboratory of Remote Sensing SciencesInstitute of Remote Sensing Applications 101001 Beijing China 3. Institute of Geographical sciences and Natural {2. Research Chinese Academy of Sciences 101001 Beijing China

The development of Web-based global 3. visual system has made progresses. However, there exist few mature and effective ways for managing, transmitting and visualizing massive spatial data. Based on the related work, the paper illustrates the ellipsoidal quadtree technique for rapid access multi-scale and multiple level geographical data, integrates the streaming with level-of-detail rendering method for transmitting the data on the network, and im-plements large-scale terrain surface simplification using M-band wavelet transforms and mul-tiresolution triangulations. We fulfil a web-based global terrain visual system using COM com-ponents on the basis of the above techniques. The system has a good prospect in the military simulation and city plans.

关键词： massive spatial data, streaming transmission, system architecture, M-band wavelet

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

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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 Academy of sciences, Beijing 10002., {2. 2. Department of Atmospheric Science, Yunnan university, Kunming 650091, {2. 3. Graduate university of the Chinese Academy of sciences, Beijing 100049, {2. 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.