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Journal of Computational Mathematics 2000年第5期18卷 513-520页

作者： Yan Gao (department of Basic science,{2. university of Mining and technology-Beijing, Beijing 100083,{2.) （北京）中国矿业大学北京 100083

This paper refers to Clarke generalized gradient for a smooth composition of max-type functions of the form: f(x) = g(x, maxj∈J1 f1j(x),''', maxj∈Jm fmj(x)), where x ∈Rn, Ji, i = 1,''',m are finite index sets, g and fij,j ∈ Ji, i = 1,... )m, are continuously differentiable on Rm+n and Rn, respectively. In a previous paper) we proposed an algorithm of finding an element of Clarke generalized gradient for f, at a point. In that paper, finding an element of Clarke generalized gradient for f, at a point, is implemented by determining the compatibilities of systems of linear inequalities many times. So its computational amount is very expensive. In this paper) we will modify the algorithm to reduce the times that the compatibilities of systems of linear inequalities have to be determined.

关键词： Nonsmooth optimization Clarke generalized gradient Max-type function.

Intense Photoluminescence and Movement of Optical Absorption Edge in Alumina Aerogels

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Journal of Materials science & technology 2000年第3期16卷 315-318页

作者： Xianting SUN, Lianzeng YAO, Chimei MO, Gang SHI, Weili CAI and Yimin ZHANG (department of Materials science and Engineering,{2., hefei 230026, china) Lide ZHANG (Institute of Solid State Physics, Chinese Academy department of Materials science and Engineering University of Science and Technology of China Hefei 230026 China department of Physics Teacher's College of Ping Ding Shan China Institute of Solid State Physics Chinese Academy of Sciences Hefei 230031 China

Alumina aerogels with high porosity of nanometer size were prepared from Al, n-butanol and ethyl acetoacetate by the sol-gel route and the N2.supercritical extraction drying technique. Optical experiment results showed that for alumina aerogels after annealing at 500℃ for 4 h one intense blue emission band appeared in the wavelength range of 400 to 800 nm, and the optical absorption edge moved from 8.0 eV of coarse grain Al2.3 to 3～eV and with increasing the annealing temperature, this luminescence band presented blue shifts. The reasons of these new optical properties are discussed in detail.

关键词： Aerogels

Spectral Radius of Non-negative Matrices and Digraphs

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Acta Mathematica Sinica,English Series 2002年第2期18卷 293-300页

作者： ZHANG Xiao Dong department of Mathematics.East china Normal {2.,Shanghai 2.0062.P.R.china E-mail:xdzhang2.hotmail.comLI Jiong Sheng department of Mathematics.{2. of science and technology of china,hefei 230026,P.R china department of Mathematics East China Normal University Shanghai P. R. China department of Mathematics University of Science and Technology of China Hefei P. R. China

We present,an upper and a lower bound for the spectral radius of non-negative matrices. Then we give the bounds for the spectral radius of digraphs.

关键词： Non-negative matrix Digraph Spectral radius

Non-isothermal Melt Crystallization Kinetics of Anhydrite-Filled Polypropylene Composites

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Journal of Wuhan university of technology(Materials {2.) 2010年第1期25卷 12-19页

作者：王少会 department of Chemistry and Chemical Engineering East China JiaoTong University

The non-isothermal crystallization kinetics of polypropylene （PP）, PP/anhydrite composites were investigated by differential scanning calorimetry （DSC） with various cooling rates. The Avrami analysis modified by Jeziorny and a method developed by Mo were employed to describe the non-isothermal crystallization process of these samples. The difference in the exponent n between PP and PP/anhydrite composites indicated that non-isothermal kinetic crystallization corresponded to tri-dimensional growth with heterogeneous nucleation. The values of half-time, Zc and F（T） showed that the crystallization rate increased with the increasing of cooling rates for PP and PP/anhydrite composites, but the crystallization rate of PP/anhydrite composites was faster than that of PP at a given cooling rate. The method developed by Ozawa did not describe the non-isothermal crystallization process of PP very well. Moreover, the method proposed by Kissinger was used to evaluate the activation energy of the mentioned samples. The result showed that the activation energy of PP/anhydrite was greatly larger than that of PP.

关键词： polypropylene anhydrite composites non-isothermal crystallization kinetics

NUMERICAL　STUDY　ON　THE　VORTEX　STRUCTURES　IN　THE　WAKE　OF　AN　OSCILLATING　CIRCULAR　CYLINDER　IN　A　UNIFORM　FLOW

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Journal of Hydrodynamics 1994年第1期6卷 12-22页

作者： Lu Xi-yun Tong Bing-gang Zhuang Li-xian Yin Xie-yuan (department of Modern Mechanics, university of science and technology of china, {2., Anhui 230026,P. R. china) Univ of science and technology of China Hefei China

Vortex shedding from a circular cylinder subjected to fortal oscillations at arbitrary angles(as shown in Fis. 1 for 0°<β<90°) with respect to the free stream is numerically investigated using the Navier-Stokes equations. The emphasis of this study is put on revealing the complicated vortex structures and their evolution in the near wake. In the present study, a number of possible vortex modes are also numerically simulated, and a variety of physical phenomena are duplicated and even renewed numerically. A parameter map indicating the classification of preferred vortex modes is firstly given in the frequency-amplitude plane.

关键词： unsteady flow vortex motion separated flow oscillatory flow.

Fast parallel algorithms for discrete Gabor expansion and transform based on multirate filtering

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science china(Information sciences) 2012年第2期55卷 293-300页

作者： TAO Liang1 & GU JuanJuan2.1School of Computer science and technology,Anhui {2.,hefei 2.0039,china 2.5} of Electronic Information and Electrical Engineering,hefei {2.,hefei 2.002.,china 1. School of Computer science and technology Anhui University Hefei 230039 China2. Department of Electronic Information and Electrical Engineering Hefei University Hefei 230022 China

The Gabor transform has long been recognized as a very useful tool for the joint time and frequency analysis in signal *** real time applications,however,were limited due to the high computational complexity of the Gabor transform *** this paper,some novel and fast parallel algorithms for the finite discrete Gabor expansion and transform are presented based on multirate *** analysis filter bank is designed for the finite discrete Gabor transform(DGT)and a synthesis filter bank is designed for the finite discrete Gabor expansion(DGE).Each of the parallel channels in the two filter banks has a unified structure and can apply the FFT and the IFFT to reduce its computational *** computational complexity of each parallel channel does not change as the oversampling rate *** fact,it is very low and depends only on the length of the input discrete signal and the number of the Gabor frequency sampling *** computational complexity of the proposed parallel algorithms is analyzed and compared with that of the major existing parallel algorithms for the finite DGT and *** results indicate that the proposed parallel algorithms for the finite DGT and DGE based on multirate filtering are very attractive for real time signal processing.

关键词： discrete Gabor expansion discrete Gabor transform critical sampling and oversampling multirate filtering analysis and synthesis filter banks

Experimental　and　Numerical　Investigation　of　Enhancement　of　Heat　and　Mass　Transfer　in　Adsorbent　Beds

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Journal of Thermal science 1994年第3期3卷 187-190页

作者： Liu Zhenyan Fu Zhuman Ge Xinshi Su Yuehong Wang Yongtang (department of Thermal science and Energy Engineering,{2.,hefei, Anhui, 230026, china) 1. department of Thermal science and Energy Engineering University of Science and Technology of China 230026 Hefei Anhui China

Some interrelated parameters of heat and mass transfer in two phases of pressure rise and constant pressure are obtained by studying the desorption processes of two kinds of cylindrical adsorbent beds,with fins and without fins. Moreover, the effects of equiValent thermal conductivity of adsorbent beds,contact thermal transfer coefficient, heat transfer of fins, condensation temperature, uncondensable gas in the adsorber are analyzed, finally, enhancement of heat and mass transfer has been attained

关键词： adsorber enhancement of heat transfer desorption

Oxyfunctionalization of ketones bearing α-methylene group with piperidine oxoammonium *** of α-diketones from monoketones

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Chinese Journal of Chemistry 1996年第3期14卷 252-258页

作者： LIU, You-Cheng REN, Tan GUO, Qing-Xiang National Laboratory of Applied Organic Chemistry, Lanzhou university,Lanzhou, Gansu 730000, china {2. of Modern Chemistry, university of science and technology of china,hefei, Anhui 230026, china National Laboratory of Applied Organic Chemistry Lanzhou University Lanzhou Gansu 730000 China department of Modern Chemistry University of Science and Technology of China Hefei Anhui 230026 China National Laboratory of Applied Organic Chemistry Lanzhou University Lanzhou Gansu 730000 China National Laboratory of Applied Organic Chemistry Lanzhou University Lanzhou Gansu 730000 China department of Modern Chemistry University of Science and Technology of China Hefei Anhui 230026 China [*]Address correspondence to this author at university of science and technology of china.

A facile method for the title transformation is described. The reaction of 2.2.6,6-tetramethyl-4-methoxypiperidine oxoammonium chloride (1b) and ketones bearing a-methylene group in acetonitrile proceeded smoothly to give the a-oxyfunctionalized coupling products (6a-h). These coupling products decomposed upon heating in acidic medium to produce a-diketones (7a-h) in good to excellent yields.

关键词： Piperidine oxoammonium salt monoketones,α-diketones synthesis

Three-Dimensional and Cross-sectional Characteristics of Normal Grain Growth Based on Monte Carlo Simulation

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International Journal of Minerals,Metallurgy and Materials 1998年第3期12卷 129-133,139页

作者： Xiaoyan Song Guoquan Liu(Material science and Engineering School, university of science and technology Beijing, Beijing 100083, china)(department of Materials science and Engineering, Hebei university of technology, Tianjin 300130, china) Material science and Engineering School University of Science and Technology Beijing Beijing 100083 China departments of Materials science and Engineering Hebei University of Technology Tianjin 300130 China

An appropriate Monte Carlo method was developed to simulate the three-dimensional normal grain growth more completely. Comparative investigation on the three-dimensional and the cross-sectional characteristics of normal grain growth was done. It was found that the time exponent of grain growth determined from cross-section exhibits the same rule of increasing slowly with time and approaching the theoretical value n = 0.5 of steadygrain growth as the three-dimensional (3-D) system. From change of the number of grains per unit area with timemeasured in cross-section, the state of 3-D normal grain growth may be predicted. The gtain size distribution incross-section is different from that in 3-D system and can not express the evolution characteristic of the 3-D distribution. Furthermore, there exists statistical connection between the topological parameters in cross-section and thosein three-dimensions.

关键词： Monte Carlo simulation normal grain growth three-dimension cross-section characteristics

A　Technique　for　Producing　Drinking　Water　from　Air　Using　Adsorbents　Driven　by　Solar　Energy：　Theoretical　and　Experimental　Research

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Journal of Thermal science 1994年第4期3卷 225-228页

作者： Chou Qiaoli Su Yuehong Ge Xinshi Wang Yongtang Cheng Shuxia(department of Thermal science and Energy Engineering,{2.,hefei, Anhui, 230026, china) 1. department of Thermal science and Energy Engineering University of Science and Technology of China 230026 Hefei Anhui China

A technique for producing driping water from air using adsorbents driven by solar energy is Presented,its principle is described, and its applicability is experimentally verified.

关键词： adsorption producing drinking water from air solar energy.