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SUPERCONVERGENCE OF DISCONTINUOUS GALERKIN METHOD FOR NONSTATIONARY HYPERBOLIC EQUATION

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Journal of Computational Mathematics 2002年第4期20卷 429-436页

作者： Chen, Y Lin, JF Lin, Q chinese acad sci Acad Math & Syst Sci ICMSEC LSEC Beijing 100080 Peoples R China

For the first order nonstationary hyperbolic equation taking the piecewise linear discontinuous Galerkin solver, we prove that under the uniform rectangular partition, such a discontinuous solver, after postprossesing, can have two and half approximative order which is half order higher than the optimal estimate by Lesaint and Raviart under the rectangular partition.

关键词： discontinuous Galerkin method hyperbolic equation nonstationary superconvergence

LMS-LIKE ESTIMATION FOR TIME VARYING PARAMETERS

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Acta Mathematica scientia 1991年第3期11卷 327-340页

作者：陈翰馥郭雷张纪峰 chinese acad sci INST SYST SCIBEIJINGPEOPLES R CHINA

An LMS-like algorithm is applied for estimating the time-varying parameter theta-n in the linear model y(n) = phi-n-tau-theta-n + upsilon-n, which is general in the sense that none of the probabilistic properties such as stationarity, Markov property, independence and ergodicity is imposed on any of the processes {y(n)}, {phi-n}, {theta-n} and {upsilon-n}. It is shown that the alpha-th moment of the estimation error is of order of the alpha-th moment of the observation noise and the parameter variation w(n) change in equivalence theta-n - theta-n-1.

关键词： LMS-LIKE ESTIMATION FOR TIME VARYING PARAMETERS der Zhang ACTA 石蕊少司

Thermal-induced polycondensation of soluble organic matter in coal of lower maturation stage

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chinese science Bulletin 1998年第6期43卷 501-504页

作者： Chunjiang Wang Yanqing Xia Binjie Luo chinese acad sci Guangzhou Inst Geochem Canton 510640 Peoples R China chinese acad sci Lanzhou Inst Geol Lanzhou 730000 Peoples R China

A brief discussion is given to the thermal-induced polycondensation of soluble organic matter (SOM) in coal during lower maturation stage, based on laboratory simulation on hydrocarbon generation from coal and on correlation with natural maturation of coal. An essential relationship between the retrogressive variation of SOM and thermal-induced polycondensation during the lower maturation stage has been established.

关键词： coal coal-derived oil lower maturation polycondensation soluble organic matter.

Photoinduced Enhancement of Gas Response Behavior of Tetra(heptyloxy)phthalocyanine Thin Film

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chinese Chemical Letters 1998年第2期9卷 207-209页

作者： Li, XY Xu, HJ Jiang, DP Lu, AD chinese acad sci Inst Photog Chem Beijing 100101 Peoples R China chinese acad sci Changchun Inst Phys Changchun 130021 Peoples R China

The response of a spin coated phthalocyanine film to 1ppm NO2 can be increased significantly by light. This may be ascribed to the irritation of phthalocyanine molecules. This irritation decreased the energy changes o... 详细信息

关键词： phthalocyanine gas sensing properties photoinduced enhancement

Upper Jaramillo polarity transition and short geomagnetic event recorded in a loess section at Jingbian, northern China

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chinese science Bulletin 1999年第20期44卷 1907-1914页

作者： Bin Guo Rixiang Zhu Zhongli Ding Jiming Sun chinese acad sci Inst Geophys Beijing 100101 Peoples R China chinese acad sci Inst Geol Beijing 100080 Peoples R China

Detailed rock-magnetic and paleomagnetic investigations have been carried out in a loess-paleosol sequence from the lower part ot unit S9 to the bottom of L11 at Jingbian (37.4° N, 108.8°E), which demonstrates that the Upper Jaramillo polarity reversal and a short geomagnetic event bounded within the Jaramillo normal subchron have been revealed. The duration of this short event was about 8.5 ka. The statistical analysis showed that the virtual geomagnet-

关键词： Upper Jaramillo short geomagnetic event loess Jingbian.

MULTIFUNCTION AND ITS APPLICATION

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Acta Mathematica scientia 1991年第4期11卷 401-408页

作者：王毓云 chinese acad sci INST SYST SCIBEIJINGPEOPLES R CHINA

1. Introduction The study of multifunction has been developed extensively with application to mathematics in economics, optimal control, game theory, mathematical programming and decision prooess, etc. Especially, it has been widely used in mathematical economics. Debreu’s work Theory of Value is closely related to the method of multifunction which economists called correspondence. Economic equilibrium theory has long been treated by calculus since Walras. Von Neumann’s work in 1943 on economic theory has been an initiative to form a’new kind of mathematical method to economic theory and reduced the dependence on calculus. The early development of mathematical economics including the 19th century and even up to the World War Ⅱ was largely in terms of calculus; it was doubtless that th(?)

关键词： MULTIFUNCTION AND ITS APPLICATION

Ecotoxicity of Cadmium to Maize and Soybean Seedling in Black Soil

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chinese Geographical science 2007年第3期17卷 270-274页

作者： Cao Huicong Wang Jinda Zhang Xuelin chinese acad sci NE Inst Geog & Agroecol Changchun 130012 Peoples R China Grad Univ Chinese Acad Sci Beijing 100049 Peoples R China

Ecotoxicity and bioavailability of cadmium （Cd） to the maize （Zea mays L.） and the soybean （Glycine max （L.） Merr.） were investigated by acute toxicity experiment in the laboratory with black soil. Ecotoxicity and bioavailability of Cd were quantified by calculating the median effective concentration （ECs0） and bioaccumulation factor （BAF）. The measurement endpoints used were seed germination and seedling growth （shoot and root）. The results showed that concentrations of Cd in the soil had adverse effect on the growth of roots and shoots. Seed germination was not the sensitive indicator for the ecotoxicity of Cd in the soil, while the growth of roots was the most sensitive measurement endpoint. Absorbability and transport of Cd in plants depended on the test crop species and Cd concentrations in the soil. The maize retains more Cd in its roots, while the soybean transports more Cd to the shoots from roots.

关键词： cadmium maize soybean ecotoxicity black soil

In-situ energy calibration of SSRF macromolecular crystallography beamline using powder diffraction

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Nuclear science and Techniques 2010年第6期21卷 321-324页

作者： Tao Shixing Zhu Jing Niu Jing Chen Mingzhi Liu Ke Wang Yu Wang Qisheng Sun Bo Huang Sheng Tang Lin He Jianhua chinese acad sci Shanghai Inst Appl Phys Shanghai 201800 Peoples R China chinese acad sci Grad Univ Beijing 100049 Peoples R China

For X-ray powder diffraction spectra collected by an area detector of MarCCD on macromolecular crystallography beamline of SSRF,an energy calibration method was developed using LaB_6(660a) powder diffraction for in-situ rapid energy calibration of the X-rays without changing the experimental *** intensity of each diffraction ring was integrated,and the accurate peak positions were fitted by Pseudo-Voigt function *** sample's interplanar spacing for XRD analysis and the calibrated energy were obtained by the PCPDFWIN code and by fitting all the energies with the least-square *** exposure time and the sample-to-detector distance were found no effect on accuracy of the energy calibration,and the in-situ energy calibration could be done with an accuracy of better than 0.4‰in 7-18 *** method is applicable to other X-ray beamlines.

关键词： X射线光束线粉末衍射能量刻度晶体学大分子光源上海 X射线衍射分析

SOME ARGUMENTS FOR RECOVERING THE FINITE ELEMENT~*

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Acta Mathematica scientia 1991年第3期11卷 290-297页

作者：林群周爱辉 chinese acad sci INST SYST SCIBEIJINGPEOPLES R CHINA

The dual argument is well known for recoving the optimal L2-error of the finite element method in elliptic context. This argument, however, will lose efficacy in hyperbolic case. An expansion argument and an approximation argument are presented in this paper to recover the optimal L2-error of finite element methods for hyperbolic problems. In particular, a second order error estimate in L2-norm for the standard linear finite element method of hyperbolic problems is obtained if the exact solution is smooth and the finite element mesh is almost uniform, and some superconvergence estimates are also established for less smooth solution.

关键词： hyperbolic argument estimates elliptic bilinear exact recover usual inequal erior