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Anomalous magnetotransport in LaMn_(1-x)Te_xO_3

Science china(Physics,Mechanics & Astronomy) 2009年第7期52卷 987-992页

作者： TAN GuoTai1,2, CHEN ZhengHao3.& ZHANG XiaoZhong4,5 1 Key Laboratory of Beam Technology & Materials Modification of the Ministry of Education, Institute of Low Energy Nuclear Physics, Beijing Normal University, Beijing 100875, china 2 Beijing radiation {3., Beijing 100875, china 3.Laboratory of Optical Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100080, china 4 Key Laboratory of Advanced Materials of the Ministry of Education, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084, china 5 Beijing National {3. for Electron Microscopy, Tsinghua University, Beijing 100084, china Key Laboratory of Beam Technology & Materials Modification of the Ministry of Education Institute of Low Energy Nuclear Physics Beijing Normal University Beijing China Beijing radiation center Beijing China Laboratory of Optical Physics Institute of Physics Chinese Academy of Sciences Beijing China Key Laboratory of Advanced Materials of the Ministry of Education Department of Materials Science and Engineering Tsinghua University Beijing China Beijing National center for Electron Microscopy Tsinghua University Beijing China

The LaMn1-xTexO3.δ (x=0.1, 0.2, 0.3. were synthesized using solid-state reaction method for the first time. X-ray photoemission spectrum (XPS) shows that in the samples the Te ions have a valence of Te4+, and Mn3. ions are partly converted into Mn2+ and Mn4+ due to the excess oxygen and Te doping. The magnetotransport associated with Mn2+, Mn3. and Mn4+ was investigated. The experimental results show that the samples are insulator at 0 T when the amount of Mn3. is much larger or less than the sum of Mn2+ and Mn4+; by contrast, the samples display metal to insulator transition with increasing temperature when the amount of Mn3. is close to the sum of Mn2+ and Mn4+. These anomalous magnetotransport behaviors were analyzed in the frame of the double-exchange (DE) mechanism.

关键词： colossal magnetoresistance La-Te-Mn-O magnetotransport

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Absolute radiometric calibration of CBERS-02 IRMSS thermal band

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Science china(Technological Sciences) 2005年第S2期48卷 72-90页

作者： ZHANG Yong1,2,3. GU Xingfa1,3.4, YU Tao1,3. ZHANG Yuxiang5, CHEN Liangfu1,3. LI Xiaoying1,2,3. LI Xiaowen1,3.& HE Liming6 1. State Key Laboratory of Remote Sensing Science, Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University, Beijing 100101, china 2. Graduate University of Chinese Academy of Sciences, Beijing 10003., china 3. The center for National Spaceborne Demonstration, Beijing 100101, china 4. Institut National de la Recherche Agronomique, Climat Sol Environnement, 84914 Avignon, France 5. National Satellite Meteorological center, Beijing 100081, china 6. State Environmental Protection Administration, Beijing 100029, china State Key Laboratory of Remote Sensing Science Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University Graduate University of Chinese Academy of Sciences The center for National Spa

Based on the laboratory calibration before launch of CBERS-02 IRMSS thermal infrared channel, the onboard blackbody calibration, the radiometric cross- calibration against TERRA MODIS corresponding channel and the in-flight field calibration at Lake Qinghai: water surface radiometric calibration test site of china on Aug. 17, 2004 are carried out in this research. When making onboard blackbody calibration of CBERS-02 IRMSS, it is necessary to understand inside structures and light path in IRMSS camera and receive and process calibration blackbody signals at normal and high temperatures. Onboard blackbody calibration results of each detector are very important to relative radiometric calibration of images processing and absolute radiometric calibration of each detector. In-flight field calibration mainly contains field experiments, obtaining synchronous images, spectrum marching and MODTRAN radiative transmi- ssion computation. Radiometric cross-calibration of CBERS-02 IRMSS thermal band against TERRA MODIS selected 6 times synchronous images of two sensors passing through Lake Qinghai and Lake Taihu from August to December, 2004 to compute the cross calibration data. Combining the in-flight field calibration and radiometric cross calibration data, the absolute radiometric calibration coefficients are calculated by the linear regression method. This new calibration model can obviously control the radiometric calibration uncertainties aroused by the single point method used in the in-flight calibration of CBERS-02 IRMSS, this kind of sensors cannot receive the cosmic background radiation. In this research, the radiometric calibration coefficients obtained through the linear regression model are 8.53.(gain, unit: DN/W m?2sr?1μm?1) and 44.92 (offset, unit: DN).

关键词： CBERS-02 IRMSS thermal band in-flight field calibration onboard blackbody calibration cross calibration.

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Refraction of light in media

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Science china(Physics,Mechanics & Astronomy) 2007年第5期50卷 591-600页

作者： ZHANG Tao Key Laboratory of Beam Technology and Material Modification of Ministry of Education, Institute of Low Energy Nuclear Physics, Beijing Normal University, Beijing 100875, china Beijing radiation {3., Beijing 100875, china Key Laboratory of Beam Technology and Material Modification of Ministry of Education Institute of Low Energy Nuclear Physics Beijing Normal University Beijing 100875 China

The roles of the magnetic field and electric field of the light are investigated when the light is refracted in the medium. The model of the electron cloud conductor is presented. Electron cloud in a molecule is treated as a conductor and the Faraday’s Law is applied to this conductor that is in the alternating magnetic field of the light. dBM/dt of the light gives rise to an alternating induced current on the electron cloud conductor, and the light exchanges energy, i.e. the refractive energy, with the elec- tron cloud conductor. Formulas of refractive index, which is the ratio of light speed in vacuum to that in the medium, are derived with this model. These formulas are tested with several mediums and Langevin’s diamagnetic susceptibility of helium gas, and the results are in good agreement with the measured data. The anisotropy and the nonlinearity of the refractive index are explained with the theory described in this work.

关键词： refractive index, light, speed, medium, propagation

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Multiple time scale evaluation of the energy balance during the maize growing season,and a new reason for energy imbalance

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Science china Earth Sciences 2009年第1期52卷 108-117页

作者： GUO JianXia1,2,BIAN LinGen3.& DAI YongJiu2 1 Meteorological Observation center of china Meteorological Administration,Beijing 100081,china 2 State Key Laboratory of Remote Sensing Science,School of Geography and Remote Sensing Science,Beijing Normal University,Beijing {3.,china 3.Chinese Academy of Meteorological Sciences,Beijing 100081,china Meteorological Observation center of china Meteorological Administration Beijing China State Key Laboratory of Remote Sensing Science School of Geography and Remote Sensing Science Beijing Normal University Beijing China Chinese Academy of Meteorological Sciences Beijing China

Energy imbalance is a common problem associated with the measurement of surface energy using the eddy covariance *** the evaluation of the energy balance,people usually pay more attention to the statistical result that the effective energy(the sum of sensible and latent heat) is systematically lower than the available energy(the difference of net radiation and ground heat flux).However,little attention has been paid to the existence of the reversed situation when the effective energy is larger than the available energy or their contribution to the overall energy closure *** this paper,based on the analysis of the energy balance on multiple time scales across the maize growth season,we conclude that the non-synchronization of energy components is the main reason for the existence of the reversed *** shifting the phase of the effective energy components half an hour ahead,the rates of energy closure over all time scales are improved and dramatically reduce the number of the half-hourly samples when the energy ratio exceeds 1 or is below *** to the characteristics of the energy distribution and transformation over multiple time scales,latent heat is always the main type of energy cost,and the residual of the energy balance increases with the growth of the maize plant surpassing the sensible heat for seventy *** is suggested that the heat storage and photosynthetic energy play an important role in the energy balance during the growing period of maize.

关键词： maize energy balance multiple time scale energy hysteresis

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Shell effect and capture cross sections in the synthesis of superheavy nuclei

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Science china(Physics,Mechanics & Astronomy) 2009年第10期52卷 1489-1493页

作者： DU SaiSai1,2,BIAN BaoAn1,2,3.LIU Min1,2,4,FENG ZhaoQing5,6 & ZHANG FengShou1,2,6 1 Key Laboratory of Beam Technology and Material Modification of Ministry of Education,College of Nuclear Science and Technology,Beijing Normal University,Beijing 100875,china 2 Beijing radiation {3.,Beijing 100875,china 3.School of Science,Jiangnan University,Wuxi 214122,china 4 College of Physics and Technology,Guangxi Normal University,Guilin 541004,china 5 Institute of Modern Physics,Chinese Academy of Sciences,Lanzhou 73.000,china 6 {3. of Theoretical Nuclear Physics,National Laboratory of Heavy Ion Accelerator of Lanzhou,Lanzhou 73.000,china Key Laboratory of Beam Technology and Material Modification of Ministry of Education College of Nuclear Science and Technology Beijing Normal University Beijing China Beijing radiation center Beijing China School of Science Jiangnan University Wuxi China College of Physics and Technology Guangxi Normal University Guilin China Institute of Modern Physics Chinese Academy of Sciences Lanzhou China center of Theoretical Nuclear Physics National Laboratory of Heavy Ion Accelerator of Lanzhou Lanzhou China

The shell effect is included in the improved isospin dependent quantum molecular dynamics model in which the shell correction energy of the system is calculated by using the deformed two-center shell model. A switch function is introduced to connect the shell correction energy of the projectile and the target with that of the compound nucleus during the dynamical fusion process. It is found that the calculated capture cross sections reproduce the experimental data quantitatively at the energy near the Coulomb barrier. The capture cross sections for reaction 3. 80 Br + 82 208 Pb → 117 288 X are also calculated and discussed.

关键词： superheavy nuclei transport theory shell effect cross sections

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Pressure-induced crystallite breaking in La_(0.7)Sr_(0.3.Mn_(0.9)Fe_(0.1)O_3.nanosolids

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Chinese Science Bulletin 1998年第6期43卷 458-461页

作者： ZHENG Fanlei 1, 2, SUI Yu 1, 3. XU Dapeng 1 and SU Wenhui 1, 4 1. Department of Physics, Jilin University, Changchun 13.023. china 2. Changchun Institute of Physics, Chinese Academy of Sciences, Changchun 13.021, china 3. Institute of Metal R Department of Physics Jilin University Changchun Chinas Changchun Institute of Physics Chinese Academy of Sciences Changchun China Institute of Metal Research Chinese Academy of Sciences Shenyang China International center for Materials Physics Chinese Academy of Sceinces Shenyang China center for Condensed Matter and radiation Physics CCAST (World Lab.) Beijing China

In the compacting process of the La 0.7Sr 0.3.n 0.9Fe 0.1O 3.nanosolids under the pressure range of 0.0-4.5 GPa, the apparent pressure-induced crystallite breaking phenomenon in these nanosolids was observed. With increasing pressure up to 4.5 GPa, the average grain size decreases by 46% while the magnetization of nanosolids decrease by 40% and their coercive increases by 3.%. This kind of breaking has a close relation to the existence of oxygen deficiency in La 0.7Sr 0.3.n 0.9Fe 0.1O 3.nanoparticles. A simple and convenient method for preparing the bulk nanosolids with a large number of clean interfaces has been suggested.

关键词： nanosolid pressure-induced breaking high pressure.

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The onset and advance of the Asian summer monsoon

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Science Bulletin 2006年第1期51卷 80-88页

作者： Lü Junmei1,2,4, ZHANG Qingyun1, TAO Shiyan1 & JU Jianhua3.1. State Key Laboratory of Numerical Modeling for Atmospheric Sci- ences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, china 2. Department of Atmospheric Sciences, Yunnan University, Kunming 650091, china 3. china Meteorological Administration Training Centre, Beijing 100081, china 4. Graduate School of Chinese Academy of Sciences, Beijing 10003., china State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Department of Atmospheric Sciences Yunnan University Kunming 650091 China Graduate School of Chinese Academy of Sciences Beijing 100039 China china Meteorological Administration Training Centre Beijing 100081 China

Based on the daily outgoing longwave radiation (OLR) data from National Oceanic and At- mospheric Administration (NOAA) satellites, the Cli- mate Prediction center’s merged analysis of pre- cipitation (CMAP) data and the National centers for Environmental Prediction/National center for At- mospheric Research (NCEP/NCAR) reanalysis dataset, the mean intraseasonal variability of the Asian summer monsoon (ASM) is investigated by using power spectrum analysis, band-pass filter, and diagnostic analyses. The processes of the onset and advance of monsoon over the southern part of Indo- china Peninsula, the east coast of Bay of Bengal, the South china Sea and the Indian subcontinent are explored. It is found that there is an abrupt change in OLR, precipitation and zonal wind during the onset and advance of the ASM. It is also indicated that the southern part of Indochina Peninsula and the adja- cent Andaman Sea is the region where the earliest onset of the ASM occurs in the 2nd pentad of May.

关键词： Asian summer monsoon intraseasonal variability onset advance.

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Inter-comparisons of thermodynamic sea-ice modeling results using various parameterizations of radiative flux

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Acta Oceanologica Sinica 2006年第1期25卷 21-31页

作者： ZHANG Zhanhai CHENG Bin LAUNIAINEN Jouko WU Huiding LIU Yu State Oceanic Administration Key Laboratory for Polar Science Polar Research Institute of China Shanghai 200136 China Finnish Institute of Marine Research Helsinki Fin-00931 Finland National Marine Environment Forecast center Beijing 100081 China

Radiative fluxes are of primary importance in the energy and mass balance of the sea-ice cover. Various parameterizations of the radiative fluxes are studied in a thermodynamic sea-ice model. Model outputs of the surface radiative and heat fluxes and mass balance are compared with observations. The contribution of short-wave radiation is limited to a long part of winter. Therefore, simple schemes are often sufficient. Errors in estimations of the short-wave radiation are due mainly to cloud effects and occasionally to multi-reflection between surface and ice crystals in the air. The long-wave radiation plays an important role in the ice surface heat and mass balance during most part of a winter. The effect of clouds on the accuracy of the simple radiative schemes is critical, which needs further attention. In general, the accuracy of an ice model depends on that of the radiative fluxes.

关键词： parameterizations of radiative fluxes energy balance at the surface of ice/snow thermodynamic sea-ice model Baltic Sea Bohai Sea

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Constraints on Cardassian universe from Gamma ray bursts

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Science china(Physics,Mechanics & Astronomy) 2010年第9期53卷 1720-1725页

作者： WANG TaiShan1 & LIANG Nan2 1 Department of Physics & center for Astrophysics,Tsinghua University,Beijing 100084,china 2 Department of Astronomy,Beijing Normal University,Beijing 100875,china Tsinghua University Department of Physics &amp center for Astrophysics Beijing China (GRID:grid.12527.33) (ISNI:***) Beijing Normal University Department of Astronomy Beijing China (GRID:grid.20513.35) (ISNI:***)

Constraints on the original Cardassian model and the modified polytropic Cardassian model are examined from the recently derived 42 gamma-ray bursts(GRBs) data calibrated with the method that can avoid the circularity *** results show that GRBs can be an optional observation to constrain the Cardassian *** the GRBs data with the newly de-rived size of baryonic acoustic oscillation peak from the Sloan Digital Sky Survey(SDSS),and the position of the first acoustic peak of the Cosmic Microwave Background radiation(CMB) from Wilkinson Microwave Anisotropy Probe(WMAP),we find Ωm0=0.27+0.02-0.02,n=0.06+0.07-0.08(1σ) for the original Cardassian model,and Ωm0=0.27+0.23.0.02,n=-0.09+0.23.1.91,β=0.82+2.10-0.62(1σ) for the modified polytropic Cardassian model.

关键词： Cardassian Gamma ray burst Cosmic Microwave Background baryonic acoustic oscillation

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Orbit determination and prediction accuracy analysis for a regional tracking network

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Science china(Physics,Mechanics & Astronomy) 2010年第6期53卷 1130-1138页

作者： ZHOU ShanShi 1,2,3.,HU XiaoGong 1 & WU Bin 1 1 Shanghai Astronomical Observatory,Chinese Academy of Sciences,Shanghai 20003.,china 2 Graduate University of Chinese Academy of Sciences,Beijing 100049,china 3.Research center of GNSS,Wuhan 43.079,china Shanghai Astronomical Observatory Chinese Academy of Sciences Shanghai China Graduate University of Chinese Academy of Sciences Beijing China Research center of GNSS Wuhan China

china's COMPASS satellite navigation system relies on a regional tracking network to provide navigation services. Limited by its geographic border,the regional network is able to cover only 3.% of the medium-earth-orbits(MEO). Accuracy of determined and predicted orbits is not able to satisfy system requirements if the tracking data processing strategy for global tracking network processing is used for the regional network. Two major error sources for orbital prediction are accuracy of initial orbital elements and dynamical modeling. To achieve better prediction accuracy,we propose a two-step orbit determination and prediction strategy. For step 1,only solar radiation pressure(SRP) parameters are estimated along with the orbital elements and other parameters; for step 2,all parameters are estimated but the SRP parameters are tightly constrained to their step 1 estimates. Experimenting with data from a regional GPS network,we conclude for orbital prediction using the proposed two-step strategy,the average user range error(URE) for 24-h prediction arcs is better than 0.6 m.

关键词： orbit determination and prediction regional tracking network URE

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