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Irregular wavelet frames on L^2.(R^n)

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Science china Mathematics 2005年第2期48卷 277-287页

作者： YANG Deyun & ZHOU Xingwei department of Information & technology, Nankai {2., Tianjin 300071, china department of Mathematics, Nankai {2., Tianjin 300071, china department of computer Science, Taishan College, Taian 2.1000, china 1. department of Information & technology Nankai University 300071 Tianjin China 2. department of Mathematics Nankai University 300071 Tianjin China 3. department of computer Science Taishan College 271000 Taian China

In this paper, we present the conditions on dilation parameter {sj}j that ensure a discrete irregular wavelet system to be a frame on L2.Rn), and for the wavelet frame we consider the perturbations of translation para... 详细信息

关键词： wavelet transform, frame, wavelet frame, irregular dilation.

Fuzzy tolerance quotient spaces and fuzzy subsets

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Science china(Information Sciences) 2010年第4期53卷 704-714页

作者： ZHANG Ling1 & ZHANG Bo2.3,4* 1computer Science & technology College, Anhui {2., Anhui 2.0039, china 2.tate Key Laboratory of Intelligent technology and Systems, Beijing 100084, china 3Tsinghua National Laboratory of Information Science & technology, Beijing 100084, china 4Information Science & technology College, computer Science & technology department, Tsinghua {2., Beijing 100084, china 1. computer Science & technology College Anhui University Anhui 230039 China2. State Key Laboratory of Intelligent Technology and Systems Beijing 100084 China3. Tsinghua National Laboratory of Information Science & Technology Beijing 100084 China4. Information Science & Technology College Computer Science & Technology Department Tsinghua University Beijing 100084 China

The structure and characteristic of fuzzy subsets are discussed by using the concepts of granulation and hierarchy in quotient space theory. First, the equivalence relation based quotient space theory is extended to the fuzzy tolerance relation. Second, the isomorphism and its discriminant of fuzzy tolerance relations are discussed. Finally, by using the fuzzy tolerance relation to define the fuzzy subset, its properties are addressed. The main results are given below: (1) several equivalent statements of fuzzy tolerance relations; (2. the definition of isomorphism of fuzzy tolerance relations; (3) the isomorphic discriminant of fuzzy tolerance relations; (4) the definition and properties of fuzzy subsets based on the fuzzy tolerance relations; and (5) the necessary and sufficient condition of the isomorphism of fuzzy subsets. These results will help us further comprehend the concepts of fuzzy tolerance relations and fuzzy subsets.

关键词： Fuzzy tolerance relation quotient space isomorphism fuzzy subset

Synthesis and Characterization of a Novel pH-sensitive Complex for Drug Release

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Journal of Wuhan university of technology(Materials Science) 2010年第1期25卷 24-27页

作者：许东颖李光吉 department of Polymer Science and Engineering South China University of Technology

A novel pH-sensitive complex was prepared by using oxidized konjac glucomannan and 4-aminosalicylic acid （4-ASA） through glutaraldehyde as a cross-linking agent. The product was characterized by FTIR and 13C NMR spectra, and the thermogravimetric analysis was also studied. The drug release studies in vitro showed that the amount of 4-ASA released from the complex was about 4%, 56% and 17% after 12.h at pH 1.2. 6.8 and 7.4, respectively. The data demonstrate that the rate of the drug release of the complex can be more effectively controlled by pH value. The results showed that the novel pH-sensitive complex could be potentially useful for colon-targeting drug delivery system.

关键词： konjac glucomannan pH-sensitivity drug release

Modern microbialites and their environmental signifi-cance,Meiji reef atoll,Nansha (Spratly) Islands,south china Sea

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Science china Earth Sciences 2008年第4期51卷 608-617页

作者： SHEN JianWei1 & WANG Yue1,2.1 department of Marine Geology, south {2. Sea Institute of Oceanology Key Laboratory of Marginal Sea Geology, south {2. Sea Institute of Oceanology and guangzhou Institute of Geochemistry, Chinese Academy of Sciences, guangzhou 510301, {2. 2.Graduate university of the Chinese Academy of Sciences, Beijing 100049, {2. department of Marine Geology South China Sea Institute of Oceanology Guangzhou China Key Laboratory of Marginal Sea Geology South China Sea Institute of Oceanology and Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou

Meiji (Mischief) coral atoll, in Nansha (Spratly) Islands, south china Sea, consists of an annular reef rim surrounding a central lagoon. On the atoll rim there are either protuberant 'motu' (small coral patch reefs on the rim of atoll) islets or lower sandy cays that contain modern microbialite deposits on the corals in pinnacles and surrounding bottoms of the atoll. Microbialites, including villiform, hairy, and thin spine growth forms, as well as gelatinous masses, mats and encrustation, developed on coral colonies and atoll rim sediments between 0 and 15 m deep-water settings. The microbialites were produced by natural populations of filamentous cyanobacteria and grew on (1) bulbous corals together with Acropora sp., (2. on massive colonies of Galaxea fascicularis, (3) on dead Montipora digitata, and (4) on dead Acropora teres, some hairy microbialite growing around broken coral branches. This study demonstrates that microbial carbonates are developed in coral reefs of south china Sea and indicates that microbial processes may be important in the construction of modern reef systems. The results have significance in the determination of nature and composition in microorganisms implied in the formation ancient microbialites, and permit evaluation of the importance of microbial deposits in mo-dern coral reefs and of 'microbialites' in biogeochemical cycles of modern coral reef systems. The re-sults also provide evidence of modern analogues for ancient microbialites in shallow-water settings, and combine with sedimentological studies of ancient microbialites to understand their controls.

关键词： Microbialite Meiji reef Nansha Island south china Sea

EXPONENTIAL ESTIMATES FOR STOCHASTIC DELAY EQUATIONS WITH NORM-BOUNDED UNCERTAINTIES

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Journal of Systems Science & Complexity 2009年第2期22卷 324-332页

作者： Hongchu WANG Shigeng HU School of Mathematics Science South China Normal University Guangzhou 510631 China. department of Mathematics Huazhong University of Science and Technology Wuhan 430074 China.

This paper presents the sufficient conditions for the exponential stability of linear or semi-linear stochastic delay equations with time-varying norm bounded parameter ***-tial estimates for the solutions are also obtained by using a modified Lyapunov-Krasovski *** conditions can be tested numerically using interior point algorithms.

关键词： Exponential estimates time delay uncertainty.

Ti/Al_2._3 Functionally Gradient Material Prepared by the Explosive Compaction/SHS Process

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Journal of Materials Science & technology 1999年第3期15卷 271-275页

作者： Yimin LI(Powder Metallurgy Research Institute, Central-south university of {2., Changsha 410083, china)Ziqiao ZHENG(department of Materials Science and Engineering, Central-south university of {2., Changsha 410083, china) Cent S Univ Technol Powder Met Res Inst Changsha 410083 Peoples R China Cent S Univ Technol Dept Mat Sci & Engn Changsha 410083 Peoples R China

Ti1Al2.3 Functionally Gradient Material (FGM) was prepared by an explosive compaction/SHS process. Ten sheets of the compounding powder were laminated and pressed to get a green body of FGM. It was then compacted explosively By burying the explosive compaction body into a stoichiometric Al/TiO2.mixture and igniting the combustion of the stoichiometric Al/TiO2.mixture, the SHS reaction of the explosive compaction body was initiated by the heat released from the combustion of the stoichiometric Al/TiO2.mixture. In this way, Ti/Al2.3 FGM was synthesized. The adiabatic temperatures of each gradient layer were calculated when the preheating temperatures were 2.8 K and 1173 K, respectively The microstructure, composition and properties of Ti/Al2.3 FGM and the reaction mechanism of each gradient layer were studied. It was found that Ti/Al2.3 FGM prepared by the explosive compaction/SHS process had a high density and a high microhardness. Its structure, composition and properties showed apparent gradient distribution. The structure of the standard stoichiometric ratio gradient layer of FGM was a network structure. Its reaction mode could be described as follows: Al powder melted first, then the molten Al penetrated into the TiO2.zone and reacted with TiO2. and big pores were left in the original positions of Al powder. The reaction of gradient layers with the addition of Al3O3 as diluents was similar to that of the standard stoichiometric ratio gradient layer, so were their structure and composition. However, the reaction of gradient layers with the addition of Ti as diluents was more complex and the composition deviated slightly from the designed one

关键词： Al SHS Ti/Al2.3 Functionally Gradient Material Prepared by the Explosive Compaction/SHS Process

Heterotetranuclear Cu_2.IPd_2.Ⅱ Complex with Bis(diphenylphosphino)methane and Diethyldithiocarbamate

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Chinese Journal of Structural Chemistry 2003年第4期22卷 435-438页

作者： SITU Yue HUANG Shao-Bin (department of Applied Chemistry, south china university of technology, {2., Guangdong 510640, china)

Self-assembly between the building blocks of Pd(Et2.tc)2.(Et2.tc = diethyldithio- carbamate) and [Cu2.m-dppm)2.MeCN)2.2. (dppm = bis(diphenylphosphino)methane) gave a new heterotetranuclear complex [Cu2.d2.m-dppm)2.m-Et2.tc)2.m3-Et2.tc)2.(ClO4)2.2. (C70H86Cl2.u2. N4O9P4Pd2.8, Mr = 1932.56), and its crystal structure has been determined by X-ray crystallo- graphy. It crystallizes in triclinic, space group P with a = 11.9834(6), b = 12.562.(6), c = 14.5603(8) ? a = 101.393 (1), b = 103.300 (1), g = 96.310(1), V = 2.63.2.2. 3, Z = 1, Dc = 1.544 g/cm3, m(MoKa) = 1336 cm-1 and F(000) = 978. The total and unique reflections are 8710 and 5400, respectively. The structure was refined to R = 0.0860 and wR = 0.1996 for 3914 observed reflections with I > 2.(I). The title complex consists of the cation [Cu2.d2.m-dppm)2.m-Et2.tc)2.m3- Et2.tc)2.2., anion ClO4- and solvate H2.. The Pd(Ⅱ) atoms are located at the approximately square-planar environments with PS3 donors and the Cu(I) atoms display distorted tetrahedral geometries.

关键词： bis(diphenylphosphino)methane diethyldithiocarbamate copper crystal structure palladium

Fuzzy tracking control design for hypersonic vehicles via T-S model

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Science china(Information Sciences) 2011年第3期54卷 521-528页

作者： GAO DaoXiang 1 & SUN ZengQi 2.1 School of technology, Beijing Forestry university, Beijing 100083, {2. 2.State Key Laboratory of Intelligent technology and System, department of computer Science and technology, Tsinghua university, Beijing 100084, {2. 1. School of technology Beijing Forestry University Beijing 100083 China2. State Key Laboratory of Intelligent Technology and System Department of Computer Science and Technology Tsinghua University Beijing 100084 China

The main focus of this paper is on designing a T-S fuzzy controller for the hypersonic vehicle. The longitudinal dynamics of the vehicle are studied using time-scale decomposition to reduce the complexity of T-S modeling. The dynamic inversion with PI control technique is applied for the slow dynamics to derive the flight path angle command and throttle setting by taking the pilot altitude and velocity command as its inputs. The T-S fuzzy controller is designed for the fast dynamics to derive the elevator deflection to track the flight path angle command. The discrepancy between the T-S model and real vehicle model is considered by using sliding mode control for the system stability. Simulation results are included to show the effectiveness of the controller.

关键词： fuzzy control T-S model sliding mode control hypersonic vehicle

Electrochemical Characterization of Surface-modified LiMn_2._4 Cathode Materials for Li-ion Batteries

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Journal of Wuhan university of technology(Materials Science) 2006年第4期21卷 56-59页

作者：禹筱元 College of Science South China Agricultural University Guangzhou 510642ChinaSchool of Physics & Engineering Sun Yat-sen University Guangzhou 510275China

To improve the performance, the surface of 12.n2.4 was coated with very fine MgO , Al2.3 and ZnO by solgel method, respectively. The structure and morphology of the coated materials were investigated by X-ray diffraction （ XRD ）, X-ray photoelectron spectroscopy （ XPS ） and scanning electron microscopy （SEM）. The charge and discharge performance of uncoated and surfnce modified 12.n2.4 spinel at 2.℃ and 55 ℃ were tested, using a voltage window of 3.0-4.35 V and a current deasity of 0. 1 C rate. There is a slight decrease in the initial discharge capacity relative to that of uncoated UMn2.O4, bat the cycle ability of 12.12.n2.4 coated by metal-oxide has remarkably been improved. The EIS measuremeuts of uncoated and Al2.3 -coated 12.n2.4 were carried out by a model 2.3 A potentiostatl galvanistat controUed by a computer using M2.0 software, and using a freqnency response analyzer （ Zsimpwin ） combined with a potentiostate （ PAR 2.3）. Coaseqnently, the reason for the improved cycle properties is that the surface modification reduces the dissolution of Mn , which results from the suppression of the electrolyte decomposition, and suppresses the formation of passivation film that acts as an electronic insulating layer. In conclusion, the use of surface modification is an effective way to improve the electrochemical performance of 12.n2.4 cathode material for lithium batteries.

关键词： lithium-ion batteries surface modification metal-oxide coating: 12.n2.4 cathode