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Sr-Nd isotopic compositions of the Changjiang sediments: Implications for tracing sediment sources

Science china Earth Sciences 2007年第10期50卷 1556-1565页

作者： YANG ShouYe1?, JIANG ShaoYong2, LING HongFei2, XIA XiaoPing3, SUN Min3 & WANG DeJie4 1 State Key Laboratory of Marine Geology, Tongji university, Shanghai 200092, china 2 State Key Laboratory for Mineral Deposit Research, nanjing university, nanjing 210093, china 3 Departmen of Earth Sciences, The university of Hong Kong, Hong Kong SAR, china 4 Development Research Center, china Geological Survey, Beijing 100083, china 1. State Key Laboratory of Marine Geology Tongji University Shanghai 200092 China 2. State Key Laboratory for Mineral Deposit Research Nanjing University Nanjing 210093 China 3. department of Earth Sciences The University of Hong Kong Hong Kong SAR China 4. Development Research Center China Geological Survey Beijing 100083 China

The suspended particulate and fine-grained floodplain sediments were collected from the main stream and tributaries of the Changjiang River for Sr-Nd isotopic measurements. The εNd(0) values gradually decrease downstream from -10.8 on average in the upper reaches to -12.3 in the lower reaches, whereas the 87Sr/86Sr ratios increase correspondingly, averaging 0.721899 and 0.725826 respectively in the upper and middle-lower reaches. The compositional variations primarily reflect the complex con- trols of provenance rocks, chemical weathering, and sediment characters between different catchments, among which the abnormal Sr-Nd isotopic compositions of the Yalong, Fujiang, Tuojiang and Yuanjiang rivers indicate the sediment provenance contributions from the Emeishan Basalt in the upper reaches and the old metamorphic and siliceous rocks in the middle-lower reaches. The Sr-Nd isotopic ratios of the Changjiang sediments can better reflect the average composition of weathered continental crust compared to other major rivers in the world because of the unique source rock types in the Changjiang drainage basin. The recognition of the Sr-Nd isotopic systematics of the Changjiang sediments will contribute to our understanding of the Changjiang evolution history and continental weathering processes during the Cenozoic, and also to reconstructing the paleoenvironmental changes in East china and the marginal seas.

关键词： Sr-Nd isotopes, sediment, Changjiang River, source rock, provenance

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Northernmost paleo-tethyan oceanic basin in Tibet:Geo-chronological evidence from ^(40)Ar/^(39)Ar age dating of Dur'ngoi ophiolite

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Chinese Science Bulletin 2001年第14期46卷 1203-1205页

作者： CHEN Liang, SUN Yong, PEI Xianzhi, GAO Ming, FENG Tao, ZHANG Zhongqing & CHEN Wen1. Laboratory of Continental Dynamics, Northwest university, Xi’an 710069, china 2. department of Geology, Northwest university, Xi’an, 710069, china 3. Institute of Geology, Chinese Academy of Geological Sciences, Beijing, 100037, china Laboratory of Continental Dynamics Northwest University Xi’an China department of Geology Northwest University Xi’an China Institute of Geology Chinese Academy of Geological Sciences Beijing China

Whole rock 40Ar/39Ar age dating has been conducted on a basalt sample from Dur’ngoi ophiolite, Qinghai Province, which was reported to be the northernmost pa-leo-tethyan oceanic basin in Tibet. A high temperature pla-teau age (345.3±7.9 Ma) with an isochorn age (336.6±7.1 Ma) has been obtained, representing the eruption time of oceanic crust Considering related geological settings, the new age provides constraints on the northernmost pa-leo-tethyan suture zone in Tibet and the tectonic evolution of Paleo-tethys in Northeast Tibet and adjacent areas.

关键词： Dur’ngoi ophlolite 40Ar -39Ar age Paleo-tethys.

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A Class of Nonlinear Nonlocal Singularly Perturbed Reaction Diffusion Systems

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Wuhan university Journal of Natural Sciences 2008年第1期13卷 9-13页

作者： CHEN Lihua department of mathematics and Computer Science Fujian Normal University Fuqing 350300 Fujian China

The singularly perturbed initial boundary value problems for the reaction diffusion system are raised. Firstly, under suitable conditions, using a iteration technique, the differential inequalities theorem is constructed and introducing two auxiliary functions the existence and uniqueness theorem of solution for the basic reaction diffusion system is proved. Using the singularly perturbed method the formal asymptotic expressions of the solution are constructed with power series theory. By using the comparison theorem the existence and its asymptotic behavior of solution for the original problem are studied. Finally, using method of estimate inequalities, the structure of solutions for the problem is discussed thoroughly in three cases and asymptotic solution of the original problem is given. The asymptotic behavior of solution in the three cases is proved.

关键词： reaction diffusion system singular perturbation initial boundary value problem

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Two-stop-two-slip motions of a dry friction oscillator

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Science china(Technological Sciences) 2010年第3期53卷 623-632页

作者： YANG ShaoPu1 & GUO ShuQi2 1 School of Mechanical Engineering,Shijiazhuang Railway Institute,Shijiazhuang 050043,china 2 department of Engineering Mechanics,Shijiazhuang Railway Institute,Shijiazhuang 050043,china 1. School of Mechanical Engineering Shijiazhuang Railway Institute Shijiazhuang 050043 China2. Department of Engineering Mechanics Shijiazhuang Railway Institute Shijiazhuang 050043 China

This paper presents the investigation on the two-stop-two-slip (TSTS) motions in a dry friction *** is a kind of dissipated *** dry friction oscillator implies complicated stick-slip *** to its nonlinear non-smooth characters,it is difficult to analyze the stick-slip ***,TSTS motion is analyzed in this paper.A closed form solution of the TSTS motions is *** addition,parameter domain for the motion is *** general,there are no explicit solutions to transcendental equation in the closed form ***,explicit solutions are possible for special ***, Poincare map is structured to analyze the stability of the motions.

关键词： dry friction non-smooth dynamics stick-slip motion

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CALCULATION OF CONFORMATIONAL ENTROPY AND FREE ENERGY OF POLYSILANE CHAIN

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Chinese Journal of Polymer Science 2001年第5期19卷 477-481页

作者： Meng-bo Luo Ying-cai Chen Jian-hua Huang Jian-min Xu department of Physics, Zhejiang university, Hangzhou 310028 china department of Physics, Taizhou Teacher’s College, Taizhou 317000 china department of Chemistry Zhejiang university Hangzhou 310028 china Zhejiang Univ Dept Phys Hangzhou 310028 Peoples R China Taizhou Teachers Coll Dept Phys Taizhou 317000 Peoples R China Zhejiang Univ Dept Chem Hangzhou 310028 Peoples R China

The conformational entropy S and free energy F were calculated by exact enumeration of polysilane chain up to 23 segments with excluded volume (EV) and long-range van der Waals (VW) interaction. A nonlinear relation between SEV+VW and chain length n was found though S-EV was found to vary linearly with n. We found that the second-order transition temperature of polysilane chain with VW interaction increases with the increase of chain length, while that of polysilane chain without VW interaction is chain length independent. Moreover, the free energies FEV+VW and F-EV are both linearly related with n, and FEV+VW < F-EV for all temperatures.

关键词： polysilane exact enumeration conformational entropy conformational free energy

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Cascade Two-photon Correlated-emission Optical Bistability

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Chinese Journal of Lasers 1998年第4期 26-33页

作者： HUANG Hongbin 1,2 SONG Jiliang 3 WEI Jiang 2 ZHANG Xiaolan 2 LU Hüi 2 ( 1 CCAST (World Laboratory), P.O.Box 8730, Beijing 100080, china 2 department of Physics, Southeast university, nanjing 210096, china 3 department

１ＩｎｔｒｏｄｕｃｔｉｏｎＩｎｔｈｅｓｔｕｄｉｅｓｏｆｔｈｅｇｅｎｅｒａｔｉｏｎｏｆｔｈｅｓｑｕｅｚｅｄｓｔａｔｅｓｏｆｌｉｇｈｔａｎｄｔｈｅｉｒｐｒｏｐｅｒｔｉｅｓ，ｔｗｏｐｈｏｔｏｎｔｒａｎｓｉｔｉｏｎｐｒｏｃ... 详细信息

１ＩｎｔｒｏｄｕｃｔｉｏｎＩｎｔｈｅｓｔｕｄｉｅｓｏｆｔｈｅｇｅｎｅｒａｔｉｏｎｏｆｔｈｅｓｑｕｅｚｅｄｓｔａｔｅｓｏｆｌｉｇｈｔａｎｄｔｈｅｉｒｐｒｏｐｅｒｔｉｅｓ，ｔｗｏｐｈｏｔｏｎｔｒａｎｓｉｔｉｏｎｐｒｏｃｅｓｅｓｈａｖｅｒｅｃｉｅｖｅｄｇ...

关键词： two photon optical bistability atomic coherences phase and photon number squeezing

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Study on Method of Fault Vibration Diagnose for Roller Overrunning Clutch

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厦门大学学报（自然科学版） 2002年第S1期41卷 216-217页

作者： LUO Yi-xin 1, DOU Yi-bing 2 (1. department of Resources Engineering, Xiangtan Polytechnic Univers ity, Xiangtan 411201,china 2. Guizhou university, Guiyang 550025, china)

Fault diagnose of the roller overrunning clutch is a headache problem in engineering at home and abroad. This paper introduces a new method to solve the problem by using the wavelet transform to separate fault si gnal and further analyzing the impact frequency. The signal local singularities under the wavelet transform are studied. According to the propagation features of modulus maximums of the fault signal and the noise under the wavelet transfor m different on the scales, and by use of the signal wavelet decomposition-recon struction algorithm, the clutch shell vibration acceleration signal is decompose d, denoised, and *** signal-to-noise of the monitored signal imp roved *** fault characteristic signal on time domain is *** f ault characteristic frequency is picked up. Experiment shows that it is quite effective.

关键词： clutch frequency fault diagnose

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Influence of La and RE on the Underside Shrinkage of ZA27 Alloy

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Journal of Rare Earths 1999年第2期17卷 47-51页

作者： Chen Yungui, Tu Mingjing, Shen Baoluo, Gao Shengji (department of Metal Materials, Sichuan university, Chengdu 610065, china) Sichuan Univ Dept Met Mat Chengdu 610065 Peoples R China

The effect of pure La and mischmetal(RE) on underside shrinkage of ZA27 alloy with cooling rate of 32 min-1 was investigated. The results show that the volumes of the underside shrinkage and the total shrinkage(underside shrinkage plus internal shrinkage) of the alloy decrease as the content of La or RE increases. When the contents of La and RE exceed 03%04%(mass fraction) respectively, the underside shrinkage is eliminated and the internal shrinkage moves upwards gradually. The mechanism that the underside shrinkage is eliminated is the falling of La and RE compounds and their accumulation on the bottom of the ZA27 alloy sample. Since La and RE can not effectively prevent phases(Al base solid solution) in the alloy from rising, the internal shrinkage is still close to the bottom of the ZA27 sample.

关键词： Rare earths Lanthanum Zinc base alloy Underside shrinkage

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Periodicity in a “Food-limited” Population Model with Toxicants and Time Delays

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Acta Mathematicae Applicatae Sinica 2002年第2期18卷 309-314页

作者： Meng Fan, Ke Wangdepartment of mathematics, Key Laboratory for Vegetation Ecology of the Ministry of Education of china, Northeast Normal university, Changchun 130024, china department of mathematics Key Laboratory for Vegetation Ecology of the Ministry of Education of China Northeast Normal University Changchun China

With the help of a continuation theorem based on Gaines and Mawhin's coincidence degree, we study the global existence of positive periodic solutions of a 'food-limited' population model with toxicants and time delays... 详细信息

关键词： Periodic solutions toxicants time delays coincidence degree

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Effect of UV Irradiation on PAN Precursor Fibers and Stabilization Process

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Journal of Wuhan university of Technology(Materials Science) 2011年第3期26卷 449-454页

作者：袁慧五 department of Chemistry and Material Naval University of Engineering

A low-cost rout for modification the polyacrylontrile（PAN） precursor fibers was *** approach involved pretreatment PAN precursor fibers with UV irradiation for various periods of time before the fibers were *** effect of UV irradiation on the chemical structure,orientation factor,density,crystallite size and morphology of the fibers in the process of stabilization was characterized by use of fourier transform infrared spectroscopy（FTIR）,float-sink procedure,X-ray diffraction（XRD）,scanning electron microscope（SEM）,*** results showed that UV irradiation could increase the density of the fibers in stabilization *** analysis indicated that the cyclization of nitrile groups was initiated at room temperature by UV *** transformation of C≡N groups to C=N ones was accelerated in the process of *** orientation factor of irradiated fibers was also *** crystallite size was decreased at first and increased later,and the better irradiation time of UV was 3 min according to the XRD *** analysis indicated that irradiation could decrease the internal and surface defects of the stabilized fibers treated at 300 ℃.

关键词： PAN precursor fibers UV irradiation cyclization crystallite size morphology

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