检索结果-南通市图书馆

Science china(technological Sciences) 2009年第7期52卷 1919-1922页

作者： LI Qiang1,2.1 School of Physics Science and technology, Xinjiang university, Urumqi 830046, china {2. of Physics, the chinese university of hongkong, shatin n.t., hongkong, china School of Physics Science and technology Xinjiang University Urumqi 830046 China department of Physics The Chinese University of HongKong Shatin N.T. HongKong China

nanostructured Fe40ni40P14B6 alloy ingots of 3―5 mm in diameter could be synthesized by a metastable liquid state spinodal decomposition method. For undercooling t> 2.0 K, the microstructure of the undercooled specimen had exhibited liquid state spinodal decomposition in.t.e undercooled liquid state. the microstructure could be described as two intertwining n.t.orks with small grains dispersed in.t.em. For undercooling t>2.0 K, the overall microstructure of the specimen changed into a granular morphology. the average grain sizes of the small and large grains are 30 nm and 80 nm, respectively. these prepared samples are soft magn.t. with saturation magn.t.zation Bs 0.744 t.

关键词： nanomaterials magn.t.c materials solidification bulk nanostructured alloy Fe40ni40P14B6 metastable liquid spinodal decomposition

nOVEL SYntHESIS OF LOnG MULtI-BLOCK HEtEROPOLYMER CHAInS WItH An ORDERED SEQUEnCE AnD COntROLLABLE BLOCK LEn.t.S

在线全文

学校读者我要写书评

暂无评论

chinese Journal of Polymer Science 2001年第5期19卷 451-454页

作者： Chi Wu Zuo-wei Xie Guang-zhao Zhang Guo-fu Zi department of Chemistry, the chinese {2. of Hong Kong shatin, n.t., Hong Kong china chinese Univ Hong Kong Dept Chem Shatin Hong Kong Peoples R China

It had very long been a dream in polymer science to synthesize long multi-block polymer chains with an orderedchain sequence and controllable block len.t.s. Using ionic or living free radical polymerization or furnishing each end ofpolymer blocks with a reactive fun.t.onal group, one can only prepare heteropolymer chains with few long blocks, such asdiblock and triblock copolymers. the most plausible result so far was a pentablock copolymer. Recently, using a combin.t.onof polymer physics and synthetic chemistry, we have invented self-assembly assisted polycondensation (SAAP). thiscommunication reports the results of using this novel. method to connect 10-100 triblock polymer chains together to formlong multi-block heteropolymer chains with an ordered sequence and controllable block len.t.s.

关键词： multi-block copolymer self assembly self assembly assisted polypolymerization novel polymer synthesis

A HYBRID POLYMER GEL AnD ItS StAtIC nOnERGODICItY

在线全文

学校读者我要写书评

暂无评论

chinese Journal of Polymer Science 2002年第3期20卷 269-274页

作者： Yue Zhao Chi Wu the Open Laboratory of Bond Selective Chemistry department of Chemical Physics, university of Science and technology of{2. Hefei 2.002.{2. department of Chemistry the chinese university of Hong Kong shatin, n.t., Hong Kong{2. Univ Sci & technol china Dept Phys Chem Open Lab Bond Select Chem Hefei 230026 Peoples R China chinese Univ Hong Kong Dept Chem Shatin Hong Kong Peoples R China

We used a thermally reversible hybrid gel made of billions of physically jam-packed swollen.t.ermally sensitivepoly(n-isopropyl-acrylamide) chemical microgels. Laser light scattering study on a series of such hybrid gels formed atdifferent gelling rates and temperatures revealed that the position-dependence of the scattering speckle pattern(staticnonergodicity) came from large voids formed during the sol-gel transition. With a proper preparation, such a nonergodicitycould be completely removed, indicating that the static nonergodicity generally observed in a gel is n.t.indinsic, but comesfrom the clustering "island" structure formed during the gelation process.

关键词： Polymer gel nonergodicity Dynamic light scattering

Perturbations of the radical of nest algebras

在线全文

学校读者我要写书评

暂无评论

chinese Science Bulletin 1998年第7期43卷 556-560页

作者： LU Fangyan 1 and LU Shijie 2.1. department of Mathematics, Suzhou university, Suzhou 2.5006,{2. 2. department of Mathematics, Zhejiang university, Hangzhou 31002.,{2. department of Mathematics Suzhou University Suzhou China department of Mathematics Zhejiang University Hangzhou China

Let R n and K-n be the radical ideal and the compact operator ideal of nest algebra t(n) respectively. It is proved thatR-n+K-n=span.t.t(n)∶tt(n)nCt}=span.t.t(n): #σ′(St)≤1, S∈t(n)}.

关键词： nest algebras radical perturbation.

Status of output regulation in uncertain nonlinear systems

在线全文

学校读者我要写书评

暂无评论

Status of output regulation in uncertain nonlinear systems

Approximation algorithms for indefin.t. complex quadratic maximization problems

第二十一届中国控制会议

作者： HUAnG Jie (department of Automation and Computer-Aided Engineering the chinese university of hongkong, {2. , n.t. , hongkong)

Output regulation problem, or altern.t.vely, servomechanisni problem, aims at designing a feedback controller to achieve asymptotic tracking of a class of reference inputs and disturbance rejection of a class of disturbances in an uncertain system while maintaining the closed-loop stability. It is a general mathematical formulation of many

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Science china Mathematics 2010年第10期53卷 2697-2708页

作者： HUAnG Yongwei1,& ZHAnG Shuzhong2.1department of Electronic and Computer Engineering,the Hong Kong university of Science and technology,Kowloon,Hong Kong,{2. 2.0} of Systems Engineering and Engineering Management,the chinese university of Hong Kong,shatin,Hong Kong,{2. 1. department of Electronic and Computer Engineering The Hong Kong University of Science and Technology Kowloon Hong Kong China2. Department of Systems Engineering and Engineering Management The Chinese University of Hong Kong Shatin Hong Kong China

In.t.is paper,we consider the following indefin.t. complex quadratic maximization problem: maximize zHQz,subject to zk ∈ C and zkm = 1,k = 1,...,n,where Q is a Hermitian matrix with trQ = 0,z ∈ Cn is the decision vector,and m *** (1/log n) approximation algorithm is presented for such ***,we consider the above problem where the objective matrix Q is in bilinear form,in which case a 0.7118 cos mπ 2.pproximation algorithm can be *** the context of quadratic optimization,various extensions and connections of the model are discussed.

关键词： indefin.t. Hermitian matrix randomized algorithms approximation ratio semidefin.t. programming relaxation

Fin.t. Volume Methods for Solving Electromagn.t.c Problems in nonhomogeneous Media

在线全文

学校读者我要写书评

暂无评论

Wuhan university Journal of n.t.ral Sciences 2003年第S1期8卷 176-182页

作者： Zou Jundepartment of Mathematics. the chinese {2. of Hong Kong, shatin, n. t. , Hong Kong, china. the chinese university of Hong Kong Department of Mathematics Shatin N. T Hong Kong China (GRID:grid.10784.3a) (ISNI:***)

this article shall review some of the recent advances on fin.t. volume methods for solving electromagn.t.c problems in nonhomogeneous media. the stability, convergence and applications of the fin.t. volume methods wil... 详细信息

关键词： Maxwell equations fin.t. volume methods stability convergence

Intern.t.onal non-governmental actors in HIV/AIDS prevention in china

在线全文

学校读者我要写书评

暂无评论

Cell Research 2005年第Z1期 919-922页

作者： Feng Shi WU* department of Government and Public Administration, chinese {2. of Hong Kong, shatin, n.t., Hong Kong SAR, china

Intern.t.onal non-governmental organizations were among the first intern.t.onal actors that responded to the emer- gence of AIDS crisis in{2.. Since 1994, the number of intern.t.onal non-governmental organizations and charitable foundations working in AIDS related issue areas in{2. has grown steadily and substantially. Despite their organiza- tional differences, most of these non-governmental actors present the characteristics of independent mission, localized practice and diverse working focus. Even.t.ough they are con.t.ained by financial and other factors compared with multilateral and bilateral official assistance agencies, they have still played a unique role in fighting again.t.AIDS in{2. as technical experts, public educators, and civil society supporters.

关键词： AIDS china nGO.

Video-based facial animation with detailed appearance texture

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Progress in n.t.ral Science:Materials Intern.t.onal 2006年第3期16卷 297-306页

作者： WAnG Jin, SUn Hanqiu and PEnG Qunsheng (department of Computer Science & technology, Xuzhou normal university, Xuzhou 2.1009,{2. State Key Laboratory of CAD & CG, Zhejiang university, Zhejiang 31002.,{2. department of Computer Science & Engineering, CUHK shatin, n.t., Hong Kong) [a]department of Computer Science & technology Xuzhou China [b]State Key Laboratory of CAD & CG Zhejiang University Zhejiang China [c]department of Computer Science & Engineering CHUK shatin N.T. Hong Kong

Facial shape transformation described by facial animation parameters (FAPs) involves the dynamic movement or deformation of eyes, brows, mouth, and lips, while detailed facial appearance concerns the facial textures such as creases, wrinkles, etc. Video-based facial animation exhibits n.t.only facial shape transformation but also detailed appearance updates. In.t.is paper, a novel algorithm for effectively extracting FAPs from video is proposed. Our system adopts the ICA-enforced direct appearance model (DAM) to track faces from video sequences; and then, FAPs are extracted from every frame of the video based on an extended model of Wincandidate 3.1. Facial appearance details are transformed from each frame by mapping an expression ratio image to the original image. We adopt wavelet to synthesize expressive details by combining the low-frequency signals of the original face and high-frequency signals of the expressive face from each frame of the video. Experimental results show that our proposed algorithm is suitable for reproducing realistic, expressive facial animations.

关键词： image based rendering facial animation texture transform.

Morita Equivalence for Factorisable Semigroups

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2001年第3期17卷 437-454页

作者： Yu Qun CHEn department of Mathematics,South china normal {2.,Guangzhou 510631,P.R.china E-mail:yqchen@scnu.edu.cnK.P.SHUM department of Mathematics,the chinese {2. of Hong Kong,shatin,n.t.,Hong Kong E-mail:kpshum@math.cuhk.edu.hk department of Mathematics South China Normal University Guangzhou 510631 P. R. China department of Mathematics The Chinese University of Hong Kong Shatin N.T. Hong Kong

Recall that the semigroups S and R are said to be strongly Morita equivalent if there exists a un.t.ry Morita context （S,R,SPR,RQS,） with and *** a factorisable semigroup S,we den.t. ζS={（s1,s2./sub>）∈S×S|ss1=ss2./sub>,S∈S},S′=S/ζS and US-FAct={SM∈ S-Act|SM=M and SHomS（S,M）≌M}.We show that,for factorisable semigroups S and R,the categories US-FAct and UR-FAct are equivalent if and only if the semigroups S′ and R′ are strongly Morita *** conditions for a factorisable semigroup to be strongly Morita equivalent to a sandwich semigroup,local un.t. semigroup,monoid and group separately are also ***,we show that a seinigroup S is completely simple if and only if S is strongly Morita equivalent to a group and for any index set I,SSHomS(S,i∈IS)→i∈IS,st·f（st）f is an S-isomorphism.

关键词： Category S-acts Fact orisable semigroup Morita equivalence