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Probing proton halo of the exotic nucleus ^(2.)S by elastic electron scattering

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Science China(physics,Mechanics & Astronomy) 2004年第1期47卷 42-51页

作者： WANG Zaijun1.& REN Zhongzhou1.2.1. {1. of physics, Nanjing {2., Nanjing 2.0008, China 2. Center of Theoretical Nuclear physics, National Laboratory of Heavy-Ion Accelerator at Lanzhou, Lanzhou 730000, China Correspondence should be addressed to Ren Zhongzhou (email: zren@*** zren99@***) Received June 1., 2.03 1. department of {1. Nanjing University 210008 Nanjing China 2. Center of Theoretical Nuclear {1. National Laboratory of Heavy-Ion Accelerator at Lanzhou 730000 Lanzhou China

Elastic electron scattering on the exotic light nucleus 2.S is investigated in the plane wave Born approximation. The variation of the squared form factors of 2.S with momentum transfer is compared with that of 32.. It is found that the behavior of the form factors near the second minimum (with a moderate momentum transfer) is sensitive to the alteration of the charge density distribution of halo protons in 2.S. This indicates that elastic electron scattering can be a good probe of the structure of proton-halo nuclei.

关键词： elastic electron scattering, cross section, form factor, proton-halo nucleus.

Synthesis and structural characterization of Zn_3N_2.powder

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Science China(physics,Mechanics & Astronomy) 2005年第2期48卷 201-210页

作者： ZONG Fujian1. MA Honglei1. XUE Chengshan2. ZHUANG Huizhao2. ZHANG Xijian1. MA Jin1. JI Feng1.& XIAO Hongdi1.1. School of physics and Microelectronics, Shandong university, Jinan 2.01.0, China 2. Institute of Semiconductor, Shandong {2. university, Jinan 2.001., China School of physics and Microelectronics Shandong University Jinan 250100 China Institute of Semiconductor Shandong Normal University Jinan 250014 China

Zinc nitride (Zn3N2. powder has been synthesized through the nitridation reaction of Zn powder with NH3 gas (at the flow rate of 500 ml/min) at the nitridation temperature of 600℃ for 1.0} min. X-ray diffraction (XRD) indicates that Zn3N2.is cubic in structure with the lattice constant being a = 0.9788 nm. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) show that Zn3N2.powder has surface morphology of various types. X-ray photoelectron spectroscopy (XPS) shows the differences in chemical bonding states between Zn3N2.and ZnO, and confirms the formation of N–Zn bonds. Observation through high resolution transmission electron microscopy (HRTEM) also indicates that the computer simulation of the structure of Zn3N2.is consistent with the structural model put forward by Partin.

关键词： nitridation, Zn3N2 powder, structure, XRD, SEM, TEM, HRTEM, XPS.

1.55 μm Wavelength Operation of E_r^(3+) -Doped Optical Fiber Bistability

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Wuhan university Journal of Natural Sciences 1999年第4期4卷 435-438页

作者： SONG Qian 1. ZHANG Yuan cheng 2.1. College of Electronics Information, Wuhan {1., Wuhan 430072. China 2. department of {2., Wuhan {1., Wuhan 430072. China Wuhan university College of Electronics Information Wuhan China (GRID:grid.49470.3e) (ISNI:***) Wuhan university Department of Physics Wuhan China (GRID:grid.49470.3e) (ISNI:***)

An all optical all fiber optical bistability operation has been realized in an all fiber cavity consisted with Er doped fiber and optical fiber loop mirrors. The experimental bistability threshold is consistent w... 详细信息

关键词： optical nonlinearity optical bistability Er doped fiber all fiber device

Study on the two and three-parameter working stability regions of 3Y-TZP suspension

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Science China(Technological Sciences) 2006年第5期49卷 547-568页

作者： CHEN Youqiang1. 2. ZHANG Xinni3, CHEN Sha’ou3 & QI Ping3 1. {1. of Chemistry, Qingdao university, Qingdao 2.6071. China 2. {1. of Chemistry, Tsinghua university, Beijing 1.0084, China 3. {1. of physics, Qingdao university, Qingdao 2.6071. China 1. department of Chemistry Qingdao University Qingdao 266071 China 2. {1. of Chemistry Tsinghua University Beijing 100084 China 3. department of {1. Qingdao University Qingdao 266071 China

We determined the variation tendency of viscosity (η) at various solids load- ing (α) for 3Y-TZP suspension as a function of dispersant concentration (Cw) using vis- cosity measurement, measured the diameter of particles as a function of Cw in very dilute suspension using light scattering method, and obtained the surface features of the sedi- ment of suspension with different Cw using SEM. We also discussed the influence of the microstructure of adsorbed polymer layers on particles and their interactions in the dis- persing medium on the stability of suspension. Then two different stable states and two different unstable states for 3Y-TZP suspension were given. Accordingly, the (Cw, η), (Cw, α), and (α, η) two-parameter, and (Cw, α, η) three-parameter stability maps were con- structed. Based on the DLVO theory calculations, the dispersant concentration, particle distance (r), and interparticle potential energy (VT) maps with various solids loading for 3Y-TZP aqueous suspension were also constructed. In (Cw, r) two-parameter coordinate system, the stable motion region map for particles was established. The Cw, α, and VT,max (the highest potential energy) surface of the potential barrier map was obtained through calculation and simulation on the basis of the surfaces of Cw, r, VT maps introduced above. The (Cw, α) two-parameter stability map was then obtained from the Cw, α, VT,max map. The results showed that this theoretical map can qualitatively prove the experimentally obtained results—the existence of different dispersed states of particles in suspension system and the variation tendency of suspension stability with changing each parame- ter—were reasonable.

关键词： 3Y-TZP, suspension, stability, DLVO theory, interparticle potential energy.

High resolution stalagmite δ1.O records over the past 1.00 years from Dongge Cave in Guizhou

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Science Bulletin 2005年第10期50卷 1003-1008页

作者： HE Yaoqi1. WANG Yongjin1. KONG Xinggong1. & CHENG Hai2. 1. College of Geography Science, Nanjing {1. university, Nanjing 2.0097, China 2. {2. of Geology and Geophysics, Minnesota university, Mineapolis MN 55455, USA College of Geography Science Nanjing Normal University Nanjing 210097 China

Based on MC-ICP-MS U-series dating and stable O-isotope analysis results, a 4―5 years resolution monsoon record over the past 1.00 years has been estab- lished for two stalagmites from Dongge Cave, Guizhou. The high resolution oxygen isotope record serves as a proxy for variations in rainfall of Asian southwest monsoon over the Yunnan-Guizhou Plateau. A close relation of the δ 1.O record with the ?1.C record from tree rings largely reflects impact of centennial-scale solar activity on the monsoon climate changes. The conspicuous decrease in the δ 1.O value at AD 1.2. indicates an abrupt increase in monsoon rainfall, sug- gesting that an atmospheric-oceanic couple over the tropical Indian Ocean plays an important role in rapid increase of the Northern Hemisphere temperature over the last century.

关键词： cave stalagmite oxygen isotope southwest monsoon solar activity Guizhou.

An initial note on quasi- stationary, cold-core Lanyu eddies southeast off Taiwan Island

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Chinese Science Bulletin 2003年第19期48卷 2101-2107页

作者： JING Chunsheng1.2.& LI Li1.1. Third Institute of Oceanography, State Oceanic Administration, Xiamen 361.05, China 2. department of Oceanography, Xiamen university, Xiamen 361.05, China Third Institute of Oceanography State Oceanic Administration Xiamen China department of Oceanography Xiamen University Xiamen China

Drifting buoys, satellite altimetry and satellite-derived sea surface thermal images are used to identify the existence of a large cold-core, cyclonic Kuroshio frontal eddy between Hengchun Peninsula and Lanyu, southeast off Taiwan Island around March 1.96. The cold eddy accompanies an offshore meander of the Kuroshio near Lanyu, about 70 km and 1.0 km in horizontal zonal and meridional scales, respectively. The cold eddy is different from normal Kuroshio frontal eddies for its persisting of about {1.months near Lanyu. Supporting evidence suggests that the Kuroshio intruded into the South China Sea (SCS, hereafter) forming a loop-like structure during the persisting period of the cold eddy and that similar eddies occur occasionally in the same location. Compared with the corresponding studies in the Gulf of Mexico, it is suggested that Lanyu cold eddies are SCS analogues of Tortugas eddies found in the southern Straits of Florida. Overshooting of the meandering Kuroshio when it leaves the SCS and effects from conservation of potential vorticity are the possible mechanism of eddy genesis.

关键词：台湾省黑潮暖流涡流寒潮飓风

Size distributions and magic number characteristics of cluster configurations formed during solidification processes of liquid metal Al

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Science China(Technological Sciences) 2006年第2期49卷 172-187页

作者： LIU Rangsu1. LIU Fengxiang1. DONG Kejun1. ZHENG Caixing1. LIU Hairong2. PENG Ping2.& LI Jiyong3 1. department of physics, Hunan {2., Changsha 41.082. China 2. department of Material Science and Engineering, Hunan {2., Changsha 41.082. China 3. department of Chemistry, Hunan {2., Changsha 41.082. China 1. department of {1. Hunan University Changsha 410082 China 2. {1. of Material Science and Engineering Hunan University Changsha 410082 China 3. department of Chemistry Hunan University Changsha 410082 China

A molecular dynamics simulation study has been performed for a large systemconsisting of 1.0000 liquid metal Al atoms to investigate the formation and magic numbercharacteristics of the cluster configurations formed during the rapid solidification processes. Thecluster-type index method (CTIM) has been adopted to describe various types of clusterconfigurations. The results indicate that the icosahedral clusters (1.0}0 1.0}0) and theircombinations play the most important role in the rnicrostructure transitions during solidificationprocesses; for the cluster configurations of different levels formed by various combinations withdiffering numbers of basic clusters, their size distributions possess obvious magic number sequencewhich is in turn as 1.(1.), 1.(2.), 2.-2.(2.), 32.33(32., 39-40, 43-44, 48..., (those in bracket arethe corresponding value in liquid state); the magic numbers correspond to the peak value positionsof the cluster numbers for corresponding level formed with various combinations by 1. 2. 3, 4, 5, 6,7, ...basic clusters, respectively. This magic number sequence is in good agreement with theexperimental results obtained by Harris et al. At the same time, this simulation study also gives ascientific and reasonable explanation to these experimental results.

关键词： liquid metal, solidification processes, cluster configuration, magic numbers, computer simulation.

Doubly contracted CI method and applications

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Science China Chemistry 2004年第4期47卷 276-282页

作者： WANG Yubin1. HAN Huixian1. ZHAI Gaohong2.,SUO Bin1.& WEN Zheny1.2.1. Institute of Modern physics, Northwest university, Xian 71.069, China 2. Laboratory of Physico-Inorganic Chemistry, {2. of Chemistry, Northwest university, Xian 71.069,China Correspondence should be addressed to Wen Zhenyi 1. Institute of Modern physics Northwest University 710069 Xian China 2. Laboratory of Physico-Inorganic Chemistry Department of Chemistry Northwest University 710069 Xi’an China

Based on the hole-particle correspondence an approximate so-called doubly contracted CI scheme is proposed. Examples calculated based on the doubly contracted CI (DCCI) scheme show that the number of configurations after contraction is reduced by three orders of magnitude, and the computation time is reduced by an order of magnitude. The examples also show that compared with experiments the DCCI and uncontracted CI have similar and reasonable accuracy to some spectroscopic parameters.

关键词： doubly contracted CI hole-particle symmetry approximate MRCI

Atomic force microscopy studies of SrTiO_(3)(001.substrates treated by chemical etching and annealing in oxygen

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Science China(physics,Mechanics & Astronomy) 2005年第4期48卷 459-468页

作者： WANG Xu1. FEI Yiyan1. LU Huibin1. JIN Kui-juan1. ZHU Xiangdong1.3, CHEN Zhenghao1. ZHOU Yueliang1.& YANG Guozhen1.1. Beijing National Laboratory for Condensed Matter physics,Institute of physics,Chinese Academy of Sciences,Beijing 1.0080,China 2. {2. of physics,university of California, Davis,California,USA 1. Beijing National Laboratory for Condensed Matter physics Institute of Physics Chinese Academy of Sciences 100080 Beijing China 2. {1. of physics University of California Davis California USA

The SrTiO3 (001. substrates treated by chemical etching in NH4F-buffered HF solution and annealing in oxygen ambient have been studied by an atomic force microscopy (AFM). The SrTiO3 substrates with TiO2.termineted and atomically smooth surfaces and single unit cell steps have been obtained. The surface morphologies of SrTiO3 substrates strongly depend on the treated conditions and the quality of the substrates.

关键词： SrTiO3, AFM, surface morphology, surface defects.