检索结果-南通市图书馆

Science China Earth sciences 2006年第5期49卷 554-560页

作者： FAN Ke1,2.3 & WANG Huijun2.1. Nansen-Zhu International Research center, institute of Atmospheric {2., chinese academy of sciences, beijing 10002., China 2. Department of Atmospheric Science, Yunnan University, Kunming 650091, China 3. Graduate University of the chinese academy of sciences, beijing 100049, China 1. Nansen-Zhu International Research center Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China 2. Department of Atmospheric Science Yunnan University Kunming 650091 China 3. Graduate University of the chinese academy of sciences Beijing 100049 China

The interannual variability of Antarctic Oscillation (AAO) and its influence on East Asian climate during both boreal winter and spring are addressed. The results show that the positive AAO anomaly decreases the cold activity over East Asia during both boreal winter and spring. AAO-related barotropic meridional teleconnection from Antarctic to Arctic is found through analysis of mean me- ridional circulations. This meridional teleconnection is remarkable over Eurasia during boreal winter and over the Pacific Ocean during boreal spring. The results also show that zonal mean zonal wind at high latitudes in Southern Hemisphere has well positive correlation with that of Eurasia during boreal winter and has negative correlation with Pacific North American teleconnection (PNA) during boreal spring, which again display the meridional teleconnection. Thus, local meridional teleconnection is a possible linkage for interaction of circulations at mid-high latitudes between both hemispheres.

关键词： Antarctic Oscillation, Eurasian west wind, meridional teleconnection, mean meridional circulation.

Negative refraction in two-dimensional photonic crystals

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2006年第10期16卷 1027-1032页

作者： REN Xiaobin, REN Kun, FENG Zhifang, FENG Shuai and REN Cheng ( School of physics Science and Information Technology, Liaocheng University, Liaocheng 2.2.59, China beijing National Laboratory for {2. matter physics, institute of physics, chinese academy of sciences, beijing 100080, China) [a]School of physics Science and Information Techonolgy Liaocheng University Liaocheng China [b]beijing National Laboratory for condensed {2. physics Institute of Physics Chinese Academy of Sciences Beijing China

Recent progress made in research on negative refraction in two-dimensional photonic crystals is reviewed. Special attentions are paid to the research results of our group. We explore the underlying mechanism governing the occurrence of negative refraction in periodic and quasiperiodic photonic crystals. These results may be useful references for the application of photonic crystals. The perspectives of future research on negative refraction are briefly predicted.

关键词： negative refraction photonic crystals superlens subwavelength imaging equifreqnency surface.

Testing local realism in P → VV decays

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2010年第5期53卷 870-875页

作者： LI JunLi1 & QIAO CongFeng1,2.1Department of physics,Graduate University of chinese academy of sciences,{2. 100049,China 2.heoretical physics center for Science Facilities(TPCSF),chinese academy of sciences,{2. 100049,China 1. Department of physics Graduate University of Chinese Academy of Sciences Beijing 100049 China2. Theoretical Physics Center for Science Facilities (TPCSF) Chinese Academy of Sciences Beijing 100049 China

It was found that the vector meson pair from the pseudoscalar decays can form an entangled *** this work we give out detailed explanations on the polarization correlation of the two entangled vector *** is demonstrated that an experimental test of the Clauser-Horne inequality can be carried out through measuring the azimuthal distribution of four pseudoscalars in the cascade decay ηc→ VV →(PP)(PP),and the measurement of this process is feasible with the current running experiments in tau-charm ***,a brief discussion on the polarization correlation of the two vector mesons from B → VV decays is also presented.

关键词： nonlocality test high energy experiment meson decays

The gravity wave instability induced by photochemistry in summer polar mesopause region

在线全文

学校读者我要写书评

暂无评论

chinese Science Bulletin 2000年第3期45卷 267-272页

作者： center for Space Science and Applied Research, chinese academy of sciences,{2., China Laboratory of Numeric Study of Heliospheric physics, chinese academy of sciences,{2., China center for Space Science and Applied Research Chinese Academy of Sciences Beijing China Laboratory of Numeric Study of Heliospheric physics Chinese Academy of Sciences Beijing China

The effect of diabatic process due to the photochemical heating and cooling on the gravity wave propagation in middle atmosphere is studied. A linear gravity wave model which considers the diabatic process is established. The unstable region and the growth rate of the gravity wave caused by photochemistry are calculated. And the comparison between the model and the adiabatic gravity wave theory of pure dynamics is made. The results indicate that the photochemical heating process can induce the instability of gravity wave at mesopause. The intensity of the instability becomes stronger as the temperature decreases. The temperature feature and the altitude characteristics of the instability are consistent with the observation. Therefore, the instability of the gravity wave induced by photochemistry may be an important mechanism in polar mesopause region in summer.

关键词： photochemistry instability gravity wave growth rate.

PREPARATION OF BISPHENOL A EPOXY RESIN WATERBORNE DISPERSIONS BY THE PHASE INVERSION EMULSIFICATION TECHNIQUE

在线全文

学校读者我要写书评

暂无评论

chinese Journal of Polymer Science 2000年第1期18卷 33-38页

作者： Zhen-zhong Yang De-lu Zhao Polymer physics Laboratory, institute of Chemistry,{2., beijing 100080, China chinese Acad Sci Inst Chem Polymer Phys Lab Beijing 100080 Peoples R China

The phase inversion emulsification technique (PIET) is an effective physical method for preparing waterborne dispersions of polymer resins. Some results concerning the preparation of bisphenol A epoxy resin waterborne dispersions by PIET in our laboratory were summarized. Electrical properties, rheological behavior and morphological evolution during phase inversion progress were systematically characterized. The effects of the emulsifier concentration and emulsification temperature on phase inversion progress and the structural features of the waterborne particles were studied as well. The deformation and break up of water drops in a shear field were analyzed in terms of micro-theology, while the interaction and coalescence dynamics of water drops were discussed in terms of DLVO theory and Smoluchowski effective collision theory, respectively. Based on the experimental results and theoretical analysis, a physical model of phase inversion progress was suggested, by which the effects of the parameters on phase inversion progress and the structural features of the waterborne particles were interpreted and predicted.

关键词： phase inversion emulsification waterborne dispersions epoxy resin mechanism physical model

Nonlinear interactions between gravity waves and background winds

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6期17卷 639-644页

作者： Liu Xiao1,2.and Xu Jiyao1(1. State Key Laboratory for Space Weather, center for Space Science and Applied Research, chinese academy of sciences,{2., China 2. Graduate University of chinese academy of sciences, beijing 100039, China) [a]State Key Laboratory for Space Weather Center for Space Science and Applied Research Chinese Academy of Sciences Beijing China [b]Graduate University of chinese academy of sciences Beijing China

Using the nonlinear propagating gravity waves (GW) model in the two-dimensional compressible atmosphere and the linear GW theory, the process of GW propagation in different background winds, e.g. the direction of the background wind is opposite to (dead wind) or the same as (tail wind) the direction of the horizontal phase velocity of GW, is studied. The results show that the dead wind prolongs the vertical wavelength and accelerates GW propagation. Therefore, GW propagates up to a higher height becomes instable in a short time and eventually induces an inverse jet flow. Then, the vertical wavelength is becoming short due to the nonlinear interactions between GW and the inverse jet flow. The vertical wavelength and group velocity decrease after GW propagates into the tail wind. The initial instable time is delayed. Although most of GW is trapped in the instable region, some of GW propagates above the instable region. Compared with GW propagation in the tail wind, the nonlinear interactions between GW and the dead wind are also strong. In contrast, the linear GW theory predicts that GW can propagate freely in the dead wind. The vertical wavelength simulated by the nonlinear numerical model is different from that predicted by the linear theory greatly after GW propagates into the dead wind.

关键词： gravity waves background winds vertical group velocity vertical wavelength nonlinear interactions.

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

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

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 {2. physics,institute of physics,chinese academy of sciences,beijing 100080,China 2. Department of physics,University of California, Davis,California,USA 1. beijing National Laboratory for condensed {2. physics Institute of Physics Chinese Academy of Sciences 100080 Beijing China 2. Department 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.

High-pressure synthesis and properties of CeO_2.ZrO_2.solid solution

在线全文

学校读者我要写书评

暂无评论

chinese Science Bulletin 2001年第10期46卷 801-806页

作者： XU Dapeng, WANG Quanyong, LU Zhe, LIU Zhiguo, ZHANG Gongmu & SU Wenhui1. Department of physics, Jilin University, Changchun 13002. China 2. International center for Materials physics, chinese academy of sciences, Shenyang 110015, China 3. center for condensed matter and Radiation physics, China center of Advanced Science and Technology (World Laboratory), beijing 100080, China Department of physics Jilin University Changchun China International center for Materials physics Chinese Academy of Sciences Shenyang China center for condensed {2. and Radiation physics China Center of Advanced Science and Technology (World Laboratory) Beijing China

Using nanoparticles of CeO2.and ZrO2.prepared by the chemical precipitation method as starting materials, the single-phase cubic Ce0.5Zr0.5O2.solid solution (c-Ce0.5Z0.5O2. has been synthesized under 3.1 GPa at 1073 K for the first time. The structure of the c-Ce0.5Zr0.5O2.has not been changed before and after annealing at 773 K for 1 h. Only an unknown EPR signal (g =1.990) has been observed in the c-Ce0.5Zr0.5O2.and not varied after annealing at 773 K for 1 h, which exhibited that there exists no Ce3+ in the c-Ce0.5Zr0.5O2.and the Ce4+ has not been reduced into Ce3+ after annealing. The transport mechanism is ionic for the c-Ce0.5Zr0.5O2. The bulk conductivity (a =1.2.10-5 S/cm at 82. K, σ=2.1 ×10-3 S/cm at 112. K) is the same as that of CeO2. but smaller than that of Y2.3-stabilized ZrO2. A marked curvature at T = 82. K has been observed in the Arrhenius plot of the bulk conductivity. The activation energy below 82. K is lower than that above 82. K, and the reason has been discussed.

关键词： CeO2.ZrO2 nanocrystalline high-pressure and -temperature solid-state reaction solid solution.

Superconductivity in Ti-doped iron-arsenide compound Sr_4Cr_(0.8)Ti_(1.2.O_6Fe_2.s_2

在线全文

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2009年第12期52卷 1876-1878页

作者： ZHU XiYu,HAN Fei,MU Gang,CHENG Peng,SHEN Bing,ZENG Bin & WEN HaiHu National Laboratory for Superconductivity,institute of physics,{2. academy of sciences,beijing 100190,China beijing Na-tional Laboratory for condensed matter physics,institute of physics,{2. academy of sciences,beijing 100190,China 1. National Laboratory for Superconductivity Institute of Physics Chinese Academy of Sciences Beijing 100190 China 2. beijing National Laboratory for condensed {2. physics Institute of Physics Chinese Academy of Sciences Beijing 100190 China

Superconductivity was achieved in Ti-doped iron-arsenide compound Sr4Cr0.8Ti1.2.6Fe2.s2.(abbreviated as Cr-FeAs-42.2.). The X-ray diffraction measurement shows that this material has a layered structure with the space group of P4/nmm,and with the lattice constants a = b = 3.9003  and c = 15.8376 . Clear diamagnetic signals in ac susceptibility data and zero-resistance in resistivity data were detected at about 6 K,confirming the occurrence of bulk superconductivity. Meanwhile we observed a supercon-ducting transition in the resistive data with the onset transition temperature at 2..2.K,which may be induced by the nonuniform distribution of the Cr/Ti content in the FeAs-42.2. phase.

关键词： iron-based superconductor high-temperature superconductor Perovskite

Interference pattern generation and simulation in the single beam of a white light continuum

在线全文

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2010年第6期53卷 1060-1064页

作者： YU ZhiHao & WENG YuXiang Laboratory of Soft matter physics,{2. of physics,chinese academy of sciences,and National Laboratory of condensed matter physics,beijing 100190,China 1. Laboratory of Soft matter physics Institute of Physics Chinese Academy of Sciences and National Laboratory of Condensed Matter Physics Beijing 100190 China

We demonstrate the interference phenomenon in the White Light Continuum(WLC) generated by a single femtosecond laser beam. Different kinds of spatial interference patterns of the WLC generation under various conditions were investigated. The spatial patterns were attributed to interference between the filaments in the WLC generated by the fundamental laser beam yielding the diffraction effect from spatial confinement. Simulations of different patterns were performed. By comparing the results of simulation with those of experiments,the distances of several micrometers between the neighboring filaments can be derived,which agree with the literature values from direct measurements.

关键词： interference supercontinuum generation ultrafast nonlinear optics