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Recent Beijing Spectroscopy (BES) results

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Science china(physics,Mechanics & Astronomy) 2008年第6期51卷 567-576页

作者： LI WeiGuo institute of High Energy physics, chinese academy of sciences, Beijing 100049, china 1. institute of High Energy physics Chinese Academy of Sciences Beijing 100049 China

Recent experimental results from Beijing Spectroscopy (BES) are reviewed, including the hadron spectroscopy from J/ψ decays, and a number of new states are found or confirmed, including σ, κ, X(1835), ωφ threshold enhancement in J/ψ→γωφ, a broad resonance in J/ψ→K + K ? π 0, decay studies of ψ(2S) and χ CJ , as well as the results of ψ(3770) non-D $ \bar D $ decays. The current status of BEPCII/BESIII, the major upgrade of BEPC/BESII, is also reported.

关键词： Beijing Spectroscopy hadron spectroscopy charm physics BEPCII

Studies on BEPC upgrade from pretzel to double-ring

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Science china(physics,Mechanics & Astronomy) 2010年第11期53卷 2084-2089页

作者： ZHANG Chuang institute of High Energy physics,chinese academy of sciences,Beijing 100049,china 1. institute of High Energy physics Chinese Academy of Sciences Beijing 100049 China

physics opportunity in the charm and τ energy region calls for higher luminosity of the Beijing Electron-Positron Collider (BEPC).The BEPC has experienced continuous improvement since its completion in ***,as a major upgrading project of the BEPC,aims at enhancing its luminosity of factor 30–100,following the principle of "one machine,two purposes" as adopted in BEPC,so that both high energy physics and synchrotron radiation experiments can be carried out with *** the BEPC to BEPCII,the double-ring scheme with multi-bunch e +-e-collision in the large crossing angle was studied in comparison with the single-ring pretzel *** the dedicated synchrotron radiation operation,artful "bridges" are designed to connect two halves of the outer ring in both the southern and the northern crossing *** paper reviews the studies on the BEPC upgrade from pretzel to double-ring structure of BEPCII.

关键词： collider storage ring high energy physics synchrotron radiation

The mechanism of the effects of the upwelling mean on the ENSO event mature phase locking

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Science china Earth sciences 2007年第8期50卷 1266-1272页

作者： YAN BangLiang CMSR, institute of Atmospheric physics, chinese academy of sciences, Beijing 100029, china 1. CMSR Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

The mechanism of the effects of the upwelling mean on the ENSO event mature phase locking is ex-amined by using a mixed-mode model. The results show that the positive feedback process of the ef-fects of the seasonal variation of the upwelling mean on the Kelvin wave is the mechanism of the locking of the event mature phase to the end of the calendar year. The memory of the Rossby waves for the sign-shifting of the sea surface temperature anomaly from positive to negative 6 months before the cold peak time is the other mechanism of the locking of the La Nia event mature phase to the end of the calendar year. The results here are different from previous ones which suggest that the balance between cold and warm trends of sea surface temperature anomaly is the mechanism involved. The cold trend is caused by the upwelling Kelvin wave from upwelling Rossby wave reflected at the western boundary, excited by the westerly anomaly stress over the central Pacific and amplified by the seasonal variation of the coupled strength in its way propagating westward. The warm trend is caused by the Kelvin wave forced by the western wind stress over the middle and eastern equatorial Pacific. The cause of the differences is due to the opposite phase of the seasonal variation of the upwelling mean to that in the observation and an improper parameterization scheme for the effects of the seasonal varia-tion of the upwelling mean on the ENSO cycle in previous studies.

关键词： Kelvin wave Rossby wave interaction between atmosphere and sea positive feedback

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 1. LASG Institute of Atmospheric Physics Chinese Academy of Sciences 100029 Beijing China 2. School of mathematics and Computer Science Nanjing Normal University 210097 Nanjing China 3. School of mathematics and System Science Chinese Academy of Sciences 100080 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 1. Key Laboratory of Metastable Materials Science and Technology Yanshan University 066004 Qinhuangdao China 2. Center for Condensed Matter physics Institute of Physics Chinese Academy of Sciences 100080 Beijing China 3. BSRF Institute of High Energy Physics Chinese Academy of Sciences 100039 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

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

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(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 200083 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