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Concatenating construction of the multisymplectic schemes for 2+1-dimensional sine-Gordon equation

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Science china mathematics 2004年第1期47卷 18-30页

作者： WANG Yushun, WANG Bin & QIN MengzhaoLASG, institute of Atmospheric physics, chinese academy of sciences, Beijing 100029, china School of mathematics and Computer Science, Nanjing Normal University, Nanjing 210097, china School of mathematics and System Science, chinese academy of sciences, Beijing 100080, china LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China School of mathematics and Computer Science Nanjing Normal University Nanjing China School of mathematics and System Science Chinese Academy of Sciences Beijing China

In this paper, taking the 2+1-dimensional sine-Gordon equation as an example, we present the concatenating method to construct the multisymplectic schemes. The method is to discretizee independently the PDEs in different directions with symplectic schemes, so that the multisymplectic schemes can be constructed by concatenating those symplectic schemes. By this method, we can construct multisymplectic schemes, including some widely used schemes with an accuracy of any order. The numerical simulation on the collisions of solitons are also proposed to illustrate the efficiency of the multisymplectic schemes.

关键词： 2+l-climensional sine-Gordon equation multisymplectic scheme concatenating method solitons

Variational calculation of the Intrashell 2p^2 ~3P^e State for Heliumlike F^( 7+) ion

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原子与分子物理学报 2000年第4期17卷 743-747页

作者： GUANG Xiao xu 1, WANG Zhi wen(Z.W.Wang) 2(1.wuhan institute of physics and mathematics, chinese academy of Science, wuhan 430071 2.Department of physics,Liaoning Normal University, Dalian 116029) 中科院武汉物理与数学所湖北武汉 430071 辽宁师范大学辽宁大连 116029

Doubly excited intrashell 2p 2 3P e state in heliumlike F 7+ ion is calculated by using the modified configuration interaction wave function. Using the modified Slater type wave function having up to 362 terms, the energy position of the discrete 2p 2 3P e state in F 7+ is determined to be -18.812 629 78 a.u., Several expectation values of r i,r -1 12 and r 12 are also given in the present work. The present results indicate that the modified Slater type wave function in which r coordinates are incorporated is effective and powerful for the description of the 2p 2 3P e state showing strong correlation effect in two electron systems.

关键词：变分计算壳层氟离子氦状态

Compression behavior of Zr_(41)Ti_(14)Cu_(12.5)Ni_(10)Be_(22.5) bulk metallic glass up to 24 GPa

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Science china(physics,Mechanics & Astronomy) 2005年第3期48卷 319-324页

作者： LI Gong 1, 2 , ZHAN Zaiji 2 , LIU Jing 3 , YUN Jinku 1 , SUN Liling 2 , LIU Riping 1 , ZHANG Jun 2 & WANG Wenkui 1, 2 1. Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, china 2. Center for Condensed Matter physics, institute of physics, chinese academy of sciences, Beijing 100080, china 3. BSRF, institute of High Energy physics, chinese academy of sciences, Beijing 100039, china Key Laboratory of Metastable Materials Science and Technology Yanshan University Qinhuangdao China Center for Condensed Matter physics Institute of Physics Chinese Academy of Sciences Beijing China BSRF Institute of High Energy Physics Chinese Academy of Sciences Beijing China

The compression of a Zr41Ti14Cu12.5Ni10Be22.5 bulk metallic glass (BMG) is investigated at room temperature up to 24 GPa using in-situ high pressure energy dispersive X-ray diffraction with a synchrotron radiation source. The pressure-induced structural relaxation is exhibited. It is found that below about 8 GPa, the existence of excess free volume contributes to the rapid structural relaxation, which gives rise to the rapid volumetric change, and the structural relaxation results in the structural stiffness under higher pressure.

关键词： bulk metallic glass, high pressure, structural relaxation, synchrotron radiation.

Effects of cosmological constant on motion of UHECR particles

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Science china(physics,Mechanics & Astronomy) 2005年第1期48卷 44-56页

作者： CHEN Shaoxia & CHANG Zhe institute of High Energy physics, chinese academy of sciences, Beijing 100039, china Graduate School of chinese academy of sciences, Beijing 100039, china institute of High Energy physics Chinese Academy of Sciences Beijing 100039 China Graduate School Chinese Academy of Sciences Beijing 100039 China

Recent astronomical observations manifest that about two-thirds of the whole energy in the Universe is contributed by a small positive cosmological constant A (> 0). Then, an asymptotically de Sitter spacetime is premised naturally. However, physics in the de Sitter spacetime is very different from that in the Minkowski spacetime. As the first step, a covariant formalism of the kinematics in the de Sitter spacetime is presented here. By solving exactly the equations of motion for a field, we obtain the dispersion relation of a free particle. It is noticed that the dispersion relation is dependent on the degree of freedom of angular momentum of the particle. We show the threshold anomaly of the ultra high energy cosmic ray disappears naturally in the framework of the de Sitter kinematics.

关键词： ultrahigh energy cosmic ray, cosmological constant, curved spacetime.

Phase approximation of spiral waves and applications

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Phase approximation of spiral waves and applications

Lepton flavor violating Z-boson decays at GigaZ as a probe of supersymmetry

第三届全国复杂动态网络学术论坛

作者： Meng Zhan wuhan institute of physics and mathematics, chinese academy of sciences, wuhan 430071, china

＜正＞Spiral wave patterns are extensively observed in excitable and oscillatory media, and the dynamics of spiral are complicated. However, in most cases we can only focus on the phase information of spiral waves and view them in the simple way. In this presentation, I will report my works by applying the phase approximation theory of spiral waves to some model studies, including the chirality effect on the global structure of spiral-domain patterns in the two-dimensional complex Ginzburg-Landau equation, which has been submitted to Physical Review E recently, the structure analysis for line defects in complex-oscillatory spiral waves, which has been published in PRE, 72, 046221 （2005） with Raymond Kapral, and the destruction of spiral waves in chaotic media, which has been published in PRE, 73, 026224 （2006） with Raymond Kapral also. Some techniques originally proposed in chaotic phase synchronization have been borrowed and developed here. In the first part, we take a closer look at the global structure of spiral-domain patterns by using phase approximation analysis and considering the unusual effect of the chirality （handedness） of spiral wave. An equation that determines the slope of shock line is derived. We generalize this analytical method to study the interaction of a pair of spirals with different rotation frequencies, and obtain the geometrical structures of the shock line and the wavefront of invasion wave in transient processing. For the last two works, read the published papers in PRE.

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Science china(physics,Mechanics & Astronomy) 2010年第11期53卷 1949-1952页

作者： YANG JinMin 1,2 1 Department of physics,Henan Normal University,Xinxiang 453007,china 2 institute of Theoretical physics,chinese academy of sciences,Beijing 100190,china Department of physics Henan Normal University Xinxiang China institute of Theoretical physics Chinese Academy of Sciences Beijing China

This paper briefly reviews the lepton flavor violating Z-decays at GigaZ as a probe of supersymmetry by focusing on Z → i j in two representative supersymmetric models: the minimal supersymmetric model without R-parity and the supersymmetric seesaw *** work concludes that under the current experimental constraints from LEP and i → j γ,these rare decays can still be enhanced to reach the sensitivity of the ***,supersymmetry can be probed via these decays at GigaZ.

关键词： Z-decay GigaZ supersymmetry

Simulation on C/A codes and analysis of GPS/pseudolite signals acquisition

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Science china(Technological sciences) 2009年第5期52卷 1459-1462页

作者： ZHANG Lei Shanghai institute of Technical physics,chinese academy of sciences,Shanghai 200083,china Shanghai institute of Technical physics Chinese Academy of Sciences Shanghai China

The global positioning system(GPS) is an extremely mature technique in the navigation and position-ing ***,there are still some limits in some aspects and for some special ***-cially,the performance of GPS needs to be improved with technological *** a GPS-like ground transmitter,the pseudolite provides a new research direction to achieve high positioning ac-curacy and *** this paper,we describe the core technologies of designing and simulation on the coarse acquisition codes in constructing the pseudolite *** the GPS/pseudolite integration system,the signal PRN 36 of the pseudolite and the GPS satellites signals are acquired in the modified receiver based on the computer software *** is shown that the pseudolite technology is ideally suited to augment the GPS alone and provide greater integrity,availability,and continuity of the navi-gation positioning system,especially for indoor use.

关键词： GPS pseudolite coarse acquisition(C/A) code acquisition

Special relativity and theory of gravity via maximum symmetry and localization

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Science china mathematics 2008年第4期51卷 568-603页

作者： GUO HanYing institute of Theoretical physics chinese academy of sciences Beijing 100080 china institute of Theoretical physics Chinese Academy of Sciences Beijing China

Like Euclid, Riemann and Lobachevski geometries are on an almost equal footing, based on the principle of relativity of maximum symmetry proposed by Professor Lu Qikeng and the postulate on invariant universal constants c and R, the de Sitter/anti-de Sitter (dS/AdS) special relativity on dS/AdS-space with radius R can be set up on an almost equal footing with Einstein’s special relativity on the Minkowski-space in the case of R→∞.Thus the dS-space is coin-like: a law of inertia in Beltrami atlas with Beltrami time simultaneity for the principle of relativity on one side, and the proper-time simultaneity and a Robertson-Walker-like dS-space with entropy and an accelerated expanding S 3 fitting the cosmological principle on another side.If our universe is asymptotic to the Robertson-Walker-like dS-space of R ? (3/Λ)1/2, it should be slightly closed in O(Λ) with entropy bound S ? 3πc 3 k B /ΛG?. Contrarily, via its asymptotic behavior, it can fix on Beltrami inertial frames without ‘an argument in a circle’ and acts as the origin of inertia.There is a triality of conformal extensions of three kinds of special relativity and their null physics on the projective boundary of a 5-d AdS-space, a null cone modulo projective equivalence [ $ \mathcal{N} $ ] ? ? P (AdS 5). Thus there should be a dS-space on the boundary of S 5 × AdS 5 as a vacuum of supergravity.In the light of Einstein’s ‘Galilean regions’, gravity should be based on the localized principle of relativity of full maximum symmetry with a gauge-like dynamics. Thus, this may lead to the theory of gravity of corresponding local symmetry. A simple model of dS-gravity characterized by a dimensionless constant g ?(ΛG?/3c 3)1/2 ～ 10?61 shows the features on umbilical manifolds of local dS-invariance. Some gravitational effects out of general relativity may play a role as dark matter.The dark universe and its asymptotic behavior may already indicate that the dS special relativity and dS-gravity be the foundati

关键词： special relativity de Sitter invariance gravity local de Sitter invariance umbilical manifold 83A05 83D05 53A35 53B50

Cyclic Heating-Annealing and Boltzmann Distribution of Free Energies in a Spin-Glass System

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Communications in Theoretical physics 2007年第7期48卷 179-182页

作者： ZHOU Hai-Jun institute of Theoretical physics,the chinese academy of sciences,Beijing 100080,china institute of Theoretical physics the Chinese Academy of Sciences Beijing 100080 China

Ergodicity of a spin-glass is broken at low temperatures;the system is trapped in one of many ergodicconfigurational *** between different ergodic domains are achievable through a *** this experiment is repeated infinite times,all ergodic configurational domains will be visited with frequencesthat decreasing exponentially with their free *** mean free energy density of a spin-glass system on a randomgraph is calculated based on this free energy Boltzmann distribution in the present work,by means of the cavity approach.

关键词： spin-glass ergodicity-broken cavity method