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Mesozoic-Cenozoic tectonic transition in Kuqa Depression-Tianshan,Northwest china:Evidence from sandstone detrital and geochemical records

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science china Earth {2. 2005年第9期48卷 1387-1402页

作者： LI Zhong1, GUO Hong2. WANG Daoxuan3.& LIN Wei1 1. Institute of Geology and Geophysics, chinese Academy of sciences, Beijing 10002., {2. 2. Tarim Oilfield Branch, CNPC, Korla 841000, {2. 3. Hefei University of Industry, Tunxilu 193. Hefei 2.0009, {2. Institute of Geology and Geophysics Chinese Academy of Sciences Beijing Chin Tarim Oilfield Branch CNPC Korla China Hefei University of Industry Hefei Chin

Similar to compositional evolution of sandstone modes and detrital heavy minerals from different profiles in the Kuqa Depression, Northwest china, major element analysis of whole sandstones from the same profiles shows four discontinuous depositional interfaces or periods, respectively corresponding to Lower Triassic\Middle Triassic, Upper Jurassic\Lower Cretaceous, Lower Cretaceous\Paleogene and Miocene\Pliocene, and indicates five-phase evolution during Mesozoic-Cenozoic: (1) From the first to fifth phase, a depositional suite changes from maroon and coarse clastic, through grey-dark grey and fine, red and coarse, red-mottled, interlayered by gypsum, to brown and coarse clastic assemblages, accompanying detrital component evolution in unstable-stable-unstable-very unstable-very unstable assem- blages. It is indicated that carbonate and complex detritus gradually dominate in sandstones in post-Late Jurassic, with rapid reduction of compositional maturity. (2. For major element geo- chemical parameters of whole sandstones, CaO and Fe2.O * 3.MgO contents show a change sequence in high-low-high-higher-highest values, with rapid increasing in post-Late Jurassic. (3. Contra some aggregative indicators for weathering indexes of sandstone detrital component, Al2.3.(CaO+Na2.) and ln(Q/(L+CE)), show a change sequence in low-high-low-lower-lowest ratios, with rapid decreasing in post-Late Jurassic. It is found that sandstone samples of the first, second and later three phases may be distinguished from the A-CN-K and A-CNK-FM diagrams respectively. Therefore, in the Kuqa Depression-Tianshan, the most important discontinuous depositional interface recording paleotectonic and paleoclimatic transition occurred in Early Triassic\Middle Triassic and Late Jurassic\Early Cretaceous, respectively, and, however, tec- tonic differentiations of basin-range system finally result in distinct depositional systems but similar detrital weathering indexes across the Lower Cretaceous\Paleogene

关键词： Tianshan, Kuqa Depression, basin-range, depositional record, tectonic transition, Mesozoic-Cenozoic.

Effects of elevated CO_2.on growth and carbon partitioning in rice

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chinese science Bulletin 1998年第23期43卷 1982-1986页

作者： LIN Weihong\+1 and WANG Dali\+2.1. Department of Plant Nutrition, china Agricultural University, Beijing 100094, china 2. Department of {2. Ecology, Research Center for Eco_Environmental science, chinese Academy of sciences, Beijing 100085, china Department of Plant Nutrition China Agricultural University Beijing China Department of systems Ecology Research Center for Eco-Environmental Science Chinese Academy of Sciences Beijing China

Rice (\%Oryza sativa\% cv. Jindao 1187) was grown in open_top chambers which contained ambient and enriched CO\-2. CO\-2.elevation stimulated rice tillering during early vegetative stage. However, panicle dry weight per plant did not change at maturity stage. Root biomass was enhanced by high CO\-2. Root / shoot ratio was increased under high CO\-2.at maturity, indicating more carbon allocation to the below_bround part in rice under high CO\-2.

关键词： CO 2 elevation growth carbon partitioning rice (\%Oryza sativa cv\%. Jindao 1187).

BOUNDARY FEEDBACK STABILIZATION OF NONUNIFORM TIMOSHENKO BEAM WITH A TIPLOAD

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chinese Annals of mathematics,Series B 2001年第4期22卷 485-494页

作者： YAN QINGXU, FENG DEXING Institute of systems science, Academy of {2. and systems science, chinese Academy of sciences, Beijing 100080, china. Institute of systems science, Academy of {2. and systems science, chinese Academy of sciences, Be Institute of systems science Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100080 China

The boundary stabilization problem of a Timoshenko beam attached with a mass at one end is studied. First, with linear boundary force feedback and moment control simultaneously at the end attached with the load, the energy corresponding to the closed loop system is proven to be exponentially convergent to zero as time t →∞. Then, some counterexamples are given to show that, in other casest the corresponding closed loop system is, in general, not stable asymtotically, let alone exponentially.

关键词： Timoshenko beam Boundary feedback control C0 semigroups Exponential stability Multiplier method

Ecological rebuilding and land reclamation in surface mines in Shanxi Province, china

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Journal of Environmental sciences 2000年第4期12卷 486-497页

作者： MIAO Ze wei 1, BAI Zhong ke 2. GAO Lin 1 (1. Research Center for Eco Environmental sciences, chinese Academy of sciences, Beijing 100085, china E\|mail: miaozewei@*** 2. Department of Soil science, Shanxi Agricultural University Taigu, 03 中科院生态环境研究中心北京 1 0 0 0 85 山西师范大学山西临汾 0 3 0 80 1

It is well known that the mining industry produces a large amount of derelict land, and causes pollution of water loss and soil erosion as well as other environmental damage in china. As land is under pressure in china, it is now policy to restore or reclaim land despoiled by mining, the aim being to develop sustainable and healthy arable land eco{2.. This paper outlines the principles and approaches of ecological restoration, which have been adopted in Shanxi Province with reference to three typical surface mines. In the research, the principles of ecological engineering and ecological succession are considered as the critical theories of ecological restoration in mine degraded land. Meanwhile, the paper made a comparative research on main links of ecological rebuilding in three surface mines in Shanxi Province, which include new land construction, treatment of toxic substances, control of soil erosion, fertility management, irrigation, ecological planning and the establishment of legislation {2.. As the research demonstrated, for successful restoration, new land construction is the fundamental framework, but it must be integrated with ecological engineering including ecological planning, the control of soil erosion and vegetation establishment and ecosystem creation in order to optimise land productivity and soil fertility. In addition, the establishment of the legislation {2. and organization of administration are also indispensable aspects of ecological rebuilding in mined land.

关键词： ecological restoration land reclamation open-pit mine

Intermediate processes and critical phenomena: Theory, method and progress of fractional operators and their applications to modern mechanics

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science china(Physics,Mechanics & Astronomy) 2006年第3期49卷 257-272页

作者： XU Mingyu1 & TAN Wenchang2.1. Institute of Applied mathematics, School of Math & System science, Shandong University, Jinan 2.0100, {2. 2. State Key Laboratory of Turbulence and Complex systems & Department of Mechanics and Engineering science, Peking University, Beijing 100871, {2. Institute of Applied mathematics School of Math & System Science Shandong University Jinan China State Key Laboratory of Turbulence and Complex systems & Department of Mechanics and Engineering science Peking University Beijing China

From point of view of physics, especially of mechanics, we briefly introduce fractional operators (with emphasis on fractional calculus and fractional differential equa- tions) used for describing intermediate processes and critical phenomena in physics and mechanics, their progress in theory and methods and their applications to modern me- chanics. Some authors’ researches in this area in recent years are included. Finally, prospects and evaluation for this subject are made.

关键词： fractional operators,intermediate processes,critical phenomena,modern mechanics

Bifurcation stabilization of nonlinear systems by dynamic output feedback with application to rotating stall control

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science china(Information {2.) 2012年第1期55卷 200-213页

作者： CHEN PengNian1,QIN HuaShu2.WANG Yong3.HONG YiGuang2.1Department of mathematics,{3. Jiliang University,Hangzhou 3.0018,{3. 2.nstitute of systems science,The chinese Academy of sciences,Beijing 100080,{3. 3.epartment of Mechanics,Peking University,Beijing 100871,{3. Department of mathematics China Jiliang University Hangzhou China Institute of systems science The Chinese Academy of Sciences Beijing China Department of Mechanics Peking University Beijing China

The paper deals with the problem of stabilization of stationary bifurcation solutions of nonlinear systems via dynamic output *** is emphasized that the parameter of the system is not directly *** introduce the concepts of uniform observability of the inverse of a function of state and input and N-order-input-to-state bifurcation *** on the concepts,we propose a new method for designing dynamic compensators that guarantee bifurcation stability for the closed-loop *** an example,we apply the general theory to active control of rotating stall in axial flow compressors by designing a stabilizing dynamic compensator for the three-state Moore-Greitzer model with a class of cubic compressor characteristics.

关键词： bifurcation control uniform observability dynamic output feedback rotating stall

A quasi-local mass for 2.spheres with negative Gauss curvature

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science china {2. 2008年第9期51卷 1644-1650页

作者： ZHANG Xiao Institute of mathematics, Academy of mathematics and {2. {3., chinese Academy of sciences, Beijing 100080, china Institute of mathematics Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing China

We extend our previous definition of quasi-local mass to 2.spheres whose Gauss curvature is negative, and prove its positivity.

关键词： general relativity quasi-local mass positivity 53.2. 53.50 83.60

Pole assignment in descriptor periodic systems

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science china {2. 2005年第10期48卷 1309-1332页

作者： FAN Hung-Yuan~1 LIN Wen-Wei~1 & XU Shufang~2.1. Department of mathematics,Tsing Hua University,Hsinchu 3.043.china 2. LMAM,School of Mathematical {2.,Peking University,Beijing 100871,china Department of mathematics Tsing Hua University Hsinchu China LMAM School of Mathematical Sciences Peking University Beijing China

In this paper a pole assignment problem is considered for the descriptor linear discrete-time periodic systems, which is using the periodic proportional-derivative feedback to modify a given system such that the closed loop system has a specified selfconjugate set of eigenvalues. It is shown that the complete reachability of an open loop periodic system is equivalent to the possibility of assigning an arbitrary set of the eigenvalues to the system by choosing the suitable periodic proportional-derivative feedback.A computational approach is also proposed to solve the problem, which uses the reliable numerical techniques based on the orthogonal transformations. Numerical examples are presented to illustrate the effectiveness of the proposed approach.

关键词： descriptor linear periodic system, pole assignment, proportional and derivative feedback, numerical method, periodic Schur decomposition.

Minimal systems of generators for central division algebra and semi-simple algebra

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chinese science Bulletin 1998年第21期43卷 1777-1780页

作者： QIU Qizhang 1 and SUN Ling 2.1. Department of mathematics, Wuhan University, Wuhan 43.072. {3. 2. Department of Information {2., Wuhan University, Wuhan 43.072. {3.. Department of mathematics Wuhan University Wuhan China Department of Information science Wuhan University Wuhan China

Suppose that F is a field of characteristic zero and (ⅰ) D is a finite-dimensional central division algabra over F; (ⅱ) A is a finite-dimensional semi-simple algabra over F. It is proved that as F-algebras, D and A ... 详细信息

关键词： central division algebra semi-simple algebra generator minimal system of generators.