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Diagnostic analysis of mesoscale rainstorms in the Jiang-Huai valley of china with convective vorticity vector

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Progress in Natural science:Materials International 2007年第5期17卷 559-568页

作者： Cui Xiaopeng, Gao Shouting and Li Xiaofan (Laboratory of Cloud-Precipitation physics and Severe Storms (LACS), Institute of Atmospheric physics, chinese academy of sciences, beijing 100029, china Joint center for Satellite Data Assimilation and NOAA/NESDIS/center for Satellite Applications and Research, Camp Springs, Maryland, USA) [a]Laboratory of Cloud-Precipitation physics and Severe Storms (LACS) Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China [b]Joint center for Satellite Data Assimilation and NOAA/NESDIS/center for Satellite Applications and ResearchCamp Springs Maryland USA

By the vector product of absolute vorticity vectors and equivalent potential temperature gradients, a new vector, convec-tive vorticity vector (CVV) is readdressed after Gao et al., and is applied to the study of the development and movement of mesoscale rainstorms in the Jiang-Huai valley of china by using high-resolution simulation data with PSU/NCAR MM5 briefly. The results show that the CVV, especially its vertical component which is closely related to interactions between vertical secondary circulations and horizontal equivalent potential temperature gradients, may be a good tracer and diagnostic tool in the study of mesoscale rainstorms in the Jiang-Huai valley of china. And the main physical processes responsible for the variations of the vertical component of the CVV are discussed briefly based on its tendency equation proposed in this article.

关键词： convective vorticity vector mesoscale rainstorms tendency equations.

Effects of gravity on the microstructure of Zr_(41)Ti_(14)-Cu_(12.5)Ni_(10)Be_(22.5) bulk glass forming alloy

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chinese science Bulletin 2001年第11期46卷 961-963页

作者： LI Gong, ZHAN Zaiji, WANG Limin, CAO Limin, SUN Liling, DAI Daoyang, ZHANG Jun & WANG WenkuiInstitute of physics, center for Condensed Matter physics, chinese academy of sciences, beijing 100080, china Department of Materials science and Engineering, Yanshan University, Qinhuangdao 066004, china Institute of physics Center for Condensed Matter Physics Chinese Academy of Sciences Beijing China Department of Materials science and Engineering Yanshan University Qinhuangdao China

The ZrTiCuNiBe alloy is melt and solidified by Bridgman unidirectional solidification on two gravity field orientations (the gravity field orientation is parallel and opposite to solidification direction). Effects of gravity on morphology and microstructure are investigated by scanning electron microscope (SEM) and X-ray diffraction (XRD). When gravity field orientation is parallel to solidificationdirection, less needle-like primary phase is embedded in a matrix eutectic; when gravity field orientation is opposite to solidification direction, a large amount of coarser needle-like primary phases were observed.

关键词： gravity field unidirectional solidification bulk amor- phous alloy.

Effects of 4DVAR with multifold observed data on the typhoon track forecast

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chinese science Bulletin 2003年第S2期48卷 93-98页

作者： WANG Yunfeng, WANG Bin, MA GANG & WANG Yushun 1. LASG, Institute of Atmospheric physics, chinese academy of sciences. beijing 100029, china: 2. National Satellite Meteorological center, beijing 100081. china chinese Acad Sci Inst Atmospher Phys LASG Beijing 100029 Peoples R China Natl Satellite Meteorol Ctr Beijing 100081 Peoples R China

Effects of 4-dimension variational data assimi-lation (4DVAR) with multifold observed data on the typhoontrack forecast are studied, by using the MM5V3 model, theRTTOVS-5 model and their adjoint models. The data usedfor assimilation include large-scale background fields data,bogus data, cloud-derived wind data, satellite inverse data,and high resolution infrared radiation sounder data (HIRS).There are 5 typhoon cases are used to perform the numericalexperiments and assimilation experiments. The numericalresults show that with 4DVAR the initial fields can be greatlyimproved and the initial typhoon structure can be clearlydescribed.

关键词： multifold observed data 4DVAR typhoon track. DOI: 10.1360/03wd0456

Profile of the composition fractions in neutron stars

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chinese science Bulletin 2002年第8期47卷 632-634页

作者： LI Wenfei, ZHANG Fengshou & CHEN Liewencenter of theoretical Nuclear physics, National Laboratory of Heavy Ion Accelerator, Lanzhou 730000, china Institute of Modern physics, chinese academy of sciences, Lanzhou 730000, china Department of physics, Shangh center of theoretical Nuclear physics National Laboratory of Heavy Ion Accelerator Lanzhou China Institute of Modern physics Chinese Academy of Sciences Lanzhou China Department of physics Shanghai Jiao Tong University Shanghai China

The composition fractions of β-stable neutron stars and their radial distributions are investigated based on Skyrme-Hartree-Fock theory and Tolman-Oppenheimer-Volkoff (TOV) equation. It is found that a pure neutron interior with a radius of 3.5 km can exist in the neutron stars. When the radius is greater than 3.5 km, the fractions of the proton, electron and μ- appear and increase with the increment of the radius, then decrease after reaching their maximum at the radius of 8 km. These results make it possible to further study the thermal evolution and magnetic properties of the neutron stars.

关键词： neutron stars compositon fractions asymmetric nuclear matter equation of state Tolman-Oppenheimer-Volkoff equation.

Re-study of Nucleon Pole Contribution in J/ψ→N(?)π Decay

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Communications in theoretical physics 2006年第9期46卷 507-513页

作者： ZONG Yuan-Yuan,~(1,2) SHEN Peng-Nian,~(1,3,4) ZOU Bing-Song,~(1,3,4) LIU Ji-Feng,~2 LIANG Wei-Hong~2 1 Institute of High Energy physics, the chinese academy of sciences, P.O. Box 918(4), beijing 100049, china 2 Department of physics, Guangxi Normal University, Guilin 541004, china 3 center of theoretical Nuclear physics, National Laboratory of Heavy Ion Accelerator, Lanzhou 730000, china 4 Institute of theoretical physics, the chinese academy of sciences, beijing 100080, china Institute of High Energy physics the Chinese Academy of Sciences P.O. Box 9184 Beijing 100049 Department of physics Guangxi Normal University Guilin 541004

We re-study nucleon pole contribution in J/ψ→NNπ decays by including the imaginary part for the propagator of the off-shell nucleon with energy above πN threshold. It is found that when including the imaginary part in the propagator, the branching ratio of the decay width will descend about 11% compared with the result without including the imaginary part, no matter whether including the off-shell form factors or not. It also leads to a phase of up to 25° for the off-shell nucleon propagator at invariant mass around 1400 MeV. This effect needs to be considered for detailed partial wave analysis of N* resonances around this mass region.

关键词： J/ψ decay form factor

High-pressure and high-tem-perature synthesis of MgB_2 and its superconductivity

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chinese science Bulletin 2001年第22期46卷 1932-1934页

作者： ZHU Jialin, LI Shaochun, YU Richeng, LI Fengying LIU Zhengxing & JIN ChangqingLaboratory for Extreme Condition physics, Institute of physics, center for Condensed Matter Physcis and beijing High Pressure Research center, chinese academy of sciences, beijing 100080, china Laboratory for Extreme Condition physics Institute of Physics Center for Condensed Matter Physcis and Beijing High Pressure Research Center Chinese Academy of Sciences Beijing China

The single-phase sample of MgB2 was prepared successfully at the temperature of 900℃ and under the pressure of 3 GPa. The structure of the sample was investigated using powder X-ray diffraction and Rietveld analysis. The results show that the structure of the sample belongs to the hexagonal structure with space group of P6/mmm, a=3.0861(5) A, c=3.5222(8) A. The magnetic and resistance measurements indicate that the superconducting transition temperature Tc is 39 K.

关键词： superconductivity magnetization resistance.

A primary study of the correlation between the net air-sea heat flux and the interannual variation of western North Pacific tropical cyclone track and intensity

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Acta Oceanologica Sinica 2011年第6期30卷 27-35页

作者： WU Liang WEN Zhiping HUANG Ronghui center for Monsoon and Environment Research/Department of Atmospheric sciences Sun Yat-sen University Guangzhou 510275 China center for Monsoon System Research Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

A singular value decomposition （SVD） analysis is carried out to reveal the relationship between the interannual variation of track and intensity of the western North Pacific tropical cyclones （WNPTCs） in the tropical cyclone （TC） active season （July–November） and the global net air-sea heat flux （Q net ） in the preceding season （April–June）. For this purpose, a tropical cyclone track and intensity function （TIF） is defined by a combination of accumulated cyclone energy （ACE） index and a cyclone track density function. The SVD analysis reveals that the first mode is responsible for the positive correlation between the upward heat flux in the tropical central Pacific and the increased activity of western North Pacific （WNP） TIF, the second mode for the positive correlation between the upward heat flux in the North Indian Ocean and the northeastward track shift of WNPTCs and the third mode for the negative correlation between the upward heat flux in mid-latitude central Pacific and the northwest displacement of the WNP TC-active center. This suggests that Q net anomalies in some key regions have a substantial remote impact on the WNP TC activity.

关键词： tropical cyclone western North Pacific the net air-sea heat flux (Q net ) interannual variation

A theoretical analysis of optical-to-THz conversion efficiency via optical rectification

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science china(Technological sciences) 2008年第12期51卷 2080-2088页

作者： LI DeHua1,QI XiaoDong2 & LIU ShengGang3 1 Terahertz Institute of Shandong University of science & Technology,Qingdao 266510,china 2 Changchun Institute of Optics,Fine Mechanics and physics,chinese academy of sciences,Changchun 130033,china 3 Terahertz research center,Physical Electronics College,University of Electronics science,Chengdu 610054,china Terahertz Institute of Shandong University of science & Technology Qingdao 266510 China Changchun Institute of Optics Fine Mechanics and Physics Chinese Academy of Sciences Changchun 130033 China Terahertz research center Physical Electronics College University of Electronics Science Chengdu 610054 China

A theoretical analysis of an ultra-short pulse converted to Terahertz radiation via optical rectification in nonlinear optical crystal is presented here;several factors that affect optical-to-THz conversion efficiencies are discussed;pulse durations affect the conversion efficiency effectively:when crystal length is equal to the optimal crystal length lc,optical-to-THz conversion efficiency is the highest,but for the periodically-inverted electro-optic crystals,conversion efficiency is almost proportional to the crystal length when absorption can be *** account of the absorption of crystals,effective length of crystal is Leff=0.63/α,there is no apparent increase of conversion efficiency and the conversion efficiency approaches to a constant eventually when the crystal length is increased.

关键词： optical rectification periodically inverted effective length conversion efficiency

Cloud microphysical and rainfall responses to zonal perturbations of sea surface temperature:A cloud-resolving modeling study

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Progress in Natural science:Materials International 2009年第5期19卷 587-594页

作者： Xiaopeng Cuia, Xiaofan Lib, Zhiping Zongc a Laboratory of Cloud-Precipitation physics and Severe Storms (LACS), Institute of Atmospheric physics, chinese academy of sciences, beijing 100029, china b Joint center for Satellite Data Assimilation and NOAA/NESDIS/Office of Research and Applications, Camp Springs, MD, USA c National Meteorological center, china Meteorological Administration, beijing 100081, china [a]Laboratory of Cloud-Precipitation physics and Severe Storms (LACS) Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China [b]Joint Center for Satellite Data Assimilation and NOAA/NESDIS/Office of Research and Applications Camp Springs MD USA [c]National Meteorological Center China Meteorological Administration Beijing 100081 China

The cloud microphysical and rainfall responses to zonal perturbations of sea surface temperature (SST) are investigated by analyzing the equilibrium simulation data (from day 31-40) obtained from a series of two-dimensional cloud-resolving simulations with a zonal model domain of 768 km. Four experiments imposed by zonal SST perturbations of wavenumbers 1 (SST29Z1), 2 (SST29Z2), 4 (SST29Z4), and 8 (SST29Z8) are compared to the control experiment imposed by zonally uniform SST (SST29). The model domain mean SST is 29 °C, and the two-dimensional cloud-resolving model with a cyclic lateral boundary is also imposed by zero vertical velocity and constant zonal wind. The time and model domain mean surface rain rates in SST29Z1, SST29Z2, and SST29Z8 are about 10% larger than those in SST29, whereas the mean surface rain rates in SST29Z4 and SST29 are similar. The analysis of mean surface rainfall budgets shows that local water vapor and hydrometeor changes play important roles in determining the differences and similarities in mean surface rain rate between the perturbation experiments and the control experiment. Both convective and stratiform rain rates are larger in SST29Z1 and SST29Z2 than in SST29 due to the smaller advection of rain from convective regions into raining stratiform regions and the larger vapor condensation rates associated with the larger water vapor convergence over raining stratiform regions in SST29Z1 and SST29Z2. The convective rain rates are larger in SST29Z4 and SST29Z8 than in SST29 because of the larger condensation rates associated with the larger water vapor convergence over convective regions in SST29Z4 and SST29Z8. The stratiform rain rates in SST29Z4 and SST29Z8 are smaller than in SST29 due to the smaller vapor condensation rates and smaller collection rates of cloud water by rain over raining stratiform regions in SST29Z4 and SST29Z8.

关键词： Cloud microphysical and rainfall responses Sea surface temperature Zonal perturbation Cloud-resolving modeling study