检索结果-南通市图书馆

ON THE LINEAR CONVERGENCE OF PC-METHOD FOR ACLASS OF LINEAR VARIATIONAL INEQUALITIES

在线全文

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 1999年第2期17卷 199-208页

作者： Nai-hua Xiu(Department of Mathematics, Nothern Jiaotong university, beijing 10004., china Instituteof Applied Mathematics, Chinese Academy Of {4., beijing 100080, china) 北方交通大学数学系北京

This paper studies the linear convergence properties of a class of the projection and contraction methods for the affine variational inequalities, and proposes a necessary and sufficient condition under which PC-Metho... 详细信息

关键词： affine variational inequality projection and contraction method linear convergence

The steady-state solution of dendritic growth from the undercooled binary alloy melt with the far field flow

在线全文

学校读者我要写书评

暂无评论

Science china(Technological sciences) 2009年第8期52卷 2280-2287页

作者： CHEN MingWen1,2, WANG ZiDong2 & XU JianJun2,3,4.1 School of Applied sciences, university of Science and Technology beijing, beijing 100083,{4. 2 School of Materials Science and Engineering, university of Science and Technology beijing, beijing 100083,{4. 3 School of Mathematical sciences, Nankai university, Tianjin 300071,{4. 4.Department of Mathematics and Statistics, McGill university, Montreal H3A 2K6, Canada School of Applied sciences University of Science and Technology Beijing Beijing 100083 China School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China School of Mathematical sciences Nankai University Tianjin 300071 China Department of Mathematics and Statistics McGill University Montreal H3A 2K6 Canada

The steady-state dendritic growth from the undercooled binary alloy melt with the far field flow is considered. By neglecting the interface energy, interface kinetics and buoyancy effects in the system, we obtaine the steady-state solution for the case of the large Schmidt number, in terms of the multiple variable expansion method. The changes of the temperature and concentration fields, the morphology of the interface, the normalization parameter and the Peclet number of the system induced by uniform external flow are derived. The results show that, compared with the system of dendritic growth from undercooled pure melt, the convective flow in the system of growth from undercooled binary alloy has stronger effects on the morphology of the interface. Nevertheless, the shape of the interface still remains nearly a paraboloid.

关键词： binary alloy melt convection dendritic growth interfaces steady-state solution multiple variable expansion method

Uniqueness and local stability for the inverse scattering problem of determining the cavity

在线全文

学校读者我要写书评

暂无评论

Science china Mathematics 2005年第8期48卷 1113-1123页

作者： FENG Lixin & MA Fuming LMAM, School of Mathematical sciences, Peking university, beijing 100871, china School of Mathematical sciences, Heilongjiang university, Harbin 150080, china School of Mathematical sciences, Jilin university, Changchun 130012, china 1. LMAM School of Mathematical Sciences Peking University 100871 Beijing China 2. School of Mathematical sciences Heilongjiang University 150080 Harbin China 3. School of Mathematical sciences Jilin University 130012 Changchun China

Considering a time-harmonic electromagnetic plane wave incident on an arbitrarily shaped open cavity embedded in infinite ground plane, the physical process is modelled by Maxwell's equations. We investigate the inverse problem of determining the shape of the open cavity from the information of the measured scattered field. Results on the uniqueness and the local stability of the inverse problem in the 2-dimensional TM (transverse magnetic) polarization are proved in this paper.

关键词： uniqueness, stability, Maxwell's equations, inverse scattering problem.

Analysis of a 2D “liquid”plasma lattice

在线全文

学校读者我要写书评

暂无评论

Science china(Physics,Mechanics & Astronomy) 2004年第1期47卷 129-136页

作者： HUA Jianjun1, LIU Yanhong1 & ZHANG Zhihe2 1. Institute of Physics, Chinese Academy of sciences, beijing 100080, china 2. College of Biomedical Engineering,{{4., beijing 100054, china Correspondence should be addressed to Hua Jianjun (email: jj_hua@***) Received September 20, 2003 1. Institute of Physics Chinese Academy of Sciences 100080 Beijing China 2. College of Biomedical Engineering Capital University of Medical Sciences 10054 Beijing China

To study the structural and dynamical properties of a 2D dusty plasma lattice, a set of experiments were performed in an environment of radio frequency discharge. Based on the results of one of the experiments, pair correlation function, bond-orientational correlation function and mean square displacement of such a system were computed and analyzed. The bond-orientational correlation function is found to fit in with the law of e?r , and the mean square displacement is found to increase monotonously with time, both of which, together with the pair correlation function, indicate that the two-dimensional dusty plasma lattice formed in the experiment stayed in a “liquid” state.

关键词： plasma lattice, pair correlation function, bond-orientational correlation function, mean square displacement.

Quantum threshold group signature

在线全文

学校读者我要写书评

暂无评论

Science china(Physics,Mechanics & Astronomy) 2008年第10期51卷 1505-1514页

作者： YANG YuGuang1,2,3 & WEN QiaoYan4.1 College of Computer Science and Technology, beijing university of Technology, beijing 100124. china 2 State Key Laboratory of Integrated Services Network, Xidian university, Xi’an 710071, china 3 State Key Laboratory of Information Security (Graduate university of Chinese Academy of sciences), beijing 10004., china 4.State Key Laboratory of Networking and Switching Technology, beijing university of Posts and Tele-communications, beijing 100876, china College of Computer Science and Technology Beijing University of Technology Beijing 100124 China State Key Laboratory of Integrated Services Network Xidian University Xi’an 710071 China State Key Laboratory of Information Security Graduate University of Chinese Academy of Sciences Beijing 100049 China State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing 100876 China

In most situations, the signer is generally a single person. However, when the message is written on behalf of an organization, a valid message may require the approval or consent of several persons. Threshold signature is a solution to this problem. Generally speaking, as an authority which can be trusted by all members does not exist, a threshold signature scheme without a trusted party appears more attractive. Following some ideas of the classical Shamir’s threshold signature scheme, a quantum threshold group signature one is proposed. In the proposed scheme, only t or more of n persons in the group can generate the group signature and any t-1 or fewer ones cannot do that. In the verification phase, any t or more of n signature receivers can verify the message and any t-1 or fewer receivers cannot verify the validity of the signature.

关键词： threshold quantum signature trusted party quantum cryptography

The evolution and morphological stability of a spherical crystal

在线全文

学校读者我要写书评

暂无评论

Science china(Technological sciences) 2008年第3期51卷 225-243页

作者： CHEN MingWen1,2, WANG ZiDong2 & XU JianJun3,4.1 School of Applied sciences, university of Science and Technology beijing, beijing 100083,{4. 2 School of Materials Science and Engineering, university of Science and Technology beijing, beijing 100083,{4. 3 School of Mathematical sciences, Nankai university, Tianjin 300071,{4. 4.Department of Mathematics and Statistics, McGill university, Montreal H3A 2K6, Canada 1. School of Applied sciences University of Science and Technology Beijing Beijing 100083 China 2. School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China 3. School of Mathematical sciences Nankai University Tianjin 300071 China 4. Department of Mathematics and Statistics McGill University Montreal H3A 2K6 Canada

The growth model of a spherical crystal in the undercooled melt including the surface energy, interfacial kinetics and convective flow is established. The effect of the convective flow induced by a small far field flow on the evolution and morphological stability of the interface of the spherical crystal is studied. The interface shape of the spherical crystal, which is affected by the far field flow, and the dispersion relation of the growth rate of amplitude of the perturbed interface are derived. It is shown that the convection induced by the far field flow makes the interface of the growing spherical crystal further grow in the upstream direction of the far field flow and inhibit growth in the downstream direction; the interface of the decaying spherical crystal further decays in the upstream direction and inhibits decay in the downstream direction. The theoretical result suggests that both the growth of the sphere in the upstream direction and the decay of the sphere in the downstream direction make the spherical crystal tend to evolve into an oval; the morphological stability of the interface depends on a certain radius R c such that the spherical crystal is unstable when its radius is greater than R c and stable when its radius is less than R c . The surface energy and interfacial kinetics have strong stabilizing effects on the growth of the spherical crystal. In the meantime interfacial kinetics is a table factor of the interface when the interface of the sphere is growing; it is an unstable factor of the interface when the interface is decaying.

关键词： solid-liquid interface spherical crystal convective flow crystal growth morphological stability

Time of impact of fragment P2 of comet SL 9 on Jupiter

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1997年第5期42卷 396-398页

作者： ZHOU Hongnan,QIAN Bochen, HUANG Keliang and LI Qibin1. Department of Astronomy, Nanjing university, Nanjing 210093, china 2. Shanghai Observatory, Chinese Academy of sciences, Shanghai 200030, china 3. Physics Department, Nanjing Normal university, Nanjing 210097, china 4. beijing Astronomical Observatory, Chinese Academy of sciences, beijing 100080, china Department of Astronomy Nanjing University Nanjing China Shanghai Observatory Chinese Academy of Sciences Shanghai China Physics Department Nanjing Normal University Nanjing China beijing Astronomical Observatory Chinese Academy of Sciences Behijing China

FROM 1994.07-16 to 1994.07-22, 21 fragments of comet SL 9 impacted against Jupiter in succession. During the impact period the impact of fragments D, E, K, N, P2 and S was observed in china. We used a 1.56-m telescope with the CCD camera of Shanghai Observatory to monitor Jupiter and its Galilean Satellites, obtaining 1000 high-quality images at B, V, I wave bands. Our data on optical wave bands are rather complete and valuable in the world. Specially, we got some images of Jupiter, Io and Europa in the impact time of fragment P2 impacting against Jupiter. This will help us understand the precise time, position, depth and energy of the P2’s collision. In this note, we report the impact time of fragment P2 of comet SL 9 and Jupiter. Since the impact of comet SL 9 was expected to take place on the side of Jupiter

关键词： comet comet Shoemaker-Levy 9 impacting against Jupiter impact time.

Cloning, sequencing and expression of the coat protein gene of Cocksfoot mottle virus

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2007年第2期17卷 222-225页

作者： DONG Zhi, GUO Xiaoyu, ZHANG Hailong and ZHANG Feiyun ( College of Life Science, capital Normal university, beijing 100037, china College of Resources Environment and Tourism, capital Normal university, beijing 100037, china beijing Key Laboratory for Resources Environment and Geography Information System, beijing 100037, china) [a]College of Life Science Capital Normal University Beijing China [b]College of Resources Environment and Tourism Capital Normal University Beijing China [c]beijing Key Laboratory for Resources Environment and Geography Information System Beijing China

The coat protein (CP) gene of Cocksfoot mottle virus (CfMV) was amplified by RT-PCR and inserted into expression vector pGEX-4.-1, and the resulting plasmid was designated as pGEXCfMV-JANCP. The fusion protein GST-CP was expressed in BL21 (DE3) pLysS after IPTG induction. The results of SDS-PAGE and Western blot analysis showed that the CfMV-CP gene was efficiently expressed in E. coli BL21 (DE3) pLysS through IPTG induction and the 56.0 kD protein was obtained.

关键词： Cocksfoot mottle virus sequence analysis prokaryotic expression.

Multiplicity of Periodic Solutions of Duffing Equations with Jumping Nonlinearities

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 Mathematicae Applicatae Sinica 2002年第3期18卷 513-522页

作者： Zai-hong WangDepartment of Mathematics, capital Normal university, beijing 100037, china Department of Mathematics Capital Normal University Beijing China

We provide sufficient conditions for the existence and multiplicity of subharrnonic solutions for Duffing's equations with jumping nonlinearities.

关键词： Periodic solution. Jumping nonlinearity PS-condition