检索结果-南通市图书馆

A comparison analysis between developed and undeveloped depressions over the South china Sea

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 1989年第2期8卷 199-208页

作者： Liang Biqi Zhang Qiuqing Department of Atmospheric Sciences, Zhongshan University, Guangzhou, china national research center for Marine Environment Forcasts, beijing, china Dept. of Atmospheric Sciences Zhangshan Univ. Guangzhou China. China

-- In this paper, by using two sets of composite data of developed and undeveloped depressions over the South china Sea, we analyze and compare the dynamic structures, the heating fields and the vorticity budget residuals of two different types of depressions. Our conclusions are as follows:The two types of depressions are similar in thermodynamical and dynamical structures. The main differ ences are : in the high layer of developed depression there is a divergence field, with a center near the zero line of vertical wind shear, and over undeveloped depression, the divergence field is weaker and the vertical wind at its center is greater than 5 m s-1. The thermodynamical field of the former is asymmetrical and that of the latter is quasi - symmetrical. As far as the dynamics structure is concerned, the convergence in the lower layer and the difference of divergence between the upper and lower layers of developed depression is three tmies larger than that of undeveloped depression. The upward motion and heating field at the center of developed depression is also stronger than that of undeveloped *** vorticity budget of the two types of depressions is mainly determined by the divergence term, the vorticity advection term and the vertical transport term. The residual term is also *** principal contribution comes from the divergence term . This is more significant for developed depression than for undeveloped depression.

关键词： over A comparison analysis between developed and undeveloped depressions over the South china Sea

Anomalous magnetotransport in LaMn_(1-x)Te_xO_3

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 center, 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 center 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

The multi-factor recombination and processes superimposition model for hydrocarbon accumulation:application to the Silurian in the Tarim Basin

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2008年第1期5卷 13-19页

作者： Meng Qingyang Pang Xiongqi Gao Jianbo State Key Laboratory of Petroleum Resource and Prospecting China University of Petroleum Beijing 102249 China Basin and Reservoir research center China University of Petroleum Beijing 102249 China research center CNOOC Beijing 100027 China

The multi-factor recombination and processes superimposition model for hydrocarbon accumulation is put forward in view of the hydrocarbon geological characteristics of multiple episodes of structural evolution, multiple sets of source-reservoir-seal assemblage, multiple cycles of hydrocarbon accumulation and multiple episodes of readjustment and reconstruction in the complex superimposed basins in china. It is a system including theories and methods that can help to predict favorable exploration regions. According to this model, the basic discipline for hydrocarbon generation, evolution and distribution in the superimposed basins can be summarized in multi-factor recombination, processes superimposition, multiple stages of oil filling and latest stage preservation. With the Silurian of the Tarim basin as an example, based on the reconstruction of the evolution history of the four factors （paleo-anticline, source rock, regional cap rock and kinematic equilibrium belt） controlling hydrocarbon accumulation, this model was adopted to predict favorable hydrocarbon accumulation areas and favorable exploration regions following structural destruction in three stages of oil filling, to provide guidance for further exploration ofoil and gas in the Silurian of the Tarim basin.

关键词： Multi-factor recombination processes superimposition Tarim Basin Silurian favorable exploration region prediction

ELASTIC-PLASTIC DYNAMIC RESPONSE OF FULLY BACKED SANDWICH PLATES UNDER LOCALIZED IMPULSIVE LOADING

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2010年第4期23卷 324-335页

作者： Hua Liu Wuchao Chen Jialing Yang (The Solid Mechanics research center, beijing University of Aeronautics and Astronautics, beijing 100191, china) The Solid Mechanics research center Beijing University of Aeronautics and Astronautics Beijing China

An analytical model is developed to assess the elastic-plastic dynamic response of fully backed sandwich plates under localized impulse *** core is modeled as an elastic-perfectly plastic *** top face sheet is treated as an individual plate resting on the *** elastic-plastic analysis for the top face sheet is based on a minimum principle in dynamic plasticity associated with the finite difference *** effects of spatial and temporal distributions of the impulsive loading on the dynamic response of sandwich plates are *** model can be used to predict the impulse-induced local effect on fully backed sandwich plates.

关键词： sandwich plate elastic plastic localized impulse plastic dissipation

Fusion tracking in color and infrared images using joint sparse representation

在线全文

学校读者我要写书评

暂无评论

Science china(Information Sciences) 2012年第3期55卷 590-599页

作者： LIU HuaPing1,2,3 & SUN FuChun1,2,3 1Department of Computer Science and Technology, Tsinghua University, beijing 100084, china 2State Key Laboratory of intelligent Technology and Systems, beijing 100084, china 3Tsinghua national Laboratory for Information Science and Technology, beijing 100084, china Department of Computer Science and Technology Tsinghua University Beijing China State Key Laboratory of intelligent Technology and Systems Beijing China Tsinghua national Laboratory for Information Science and Technology Beijing China

Currently sparse signal reconstruction gains considerable interest and is applied in many fields. In this paper, a similarity induced by joint sparse representation is designed to construct the likelihood function of particle filter tracker so that the color visual spectrum and thermal spectrum images can be fused for object tracking. The proposed fusion scheme performs joint sparse representation calculation on both modalities and the resultant tracking results are fused using min operation on the sparse representation coefficients. In addition, a co-learning approach is proposed to update the reference templates of both modality and enhance the tracking robustness. The proposed fusion scheme outperforms state-of-the-art approaches, and its effectiveness is verified using OTCBVS database.

关键词： joint sparse representation fusion tracking color image infrared image

Response of remotely sensed Normalized Difference Water Deviation Index to the 2006 Drought of eastern Sichuan Basin

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 Earth Sciences 2008年第5期51卷 748-758页

作者： ZHANG WenJiang1, LU QiFeng2, GAO ZhiQiang3 & PENG Jian4 1 School of Water Resource and Hydropower, Sichuan University, Chengdu 610065, china 2 national Satellite Meteorological center, china Meteorological Administration, beijing 100081, china 3 Institute of Geographic Sciences and Natural Resources research, Chinese Academy of Sciences, beijing 100101, china 4 School of Environmental Sciences, Peking University, beijing 100871, china School of Water Resource and Hydropower Sichuan University Chengdu China national Statellite Meteorological center China Meteorological Administration Beijing China Institute of Geographic Sciences and Natural Resources research Chinese Academy of Sciences Beijing China School of Environmental Sciences Peking University Beijing China

One of the most serious droughts in last century occurred in eastern Sichuan Basin in the summer of 2006 (hereinafter called the Drought). The response of Moderate Resolution Imaging Spectroradiometer (MODIS, boarding on NASA satellites of Terra and Aqua) to the Drought was analyzed in order to reach one practicable monitoring solution for regional soil moisture. Temporal process and spatial extension of the Drought were firstly estimated with ground meteorological and hydrological observations. Then, for the whole region of Sichuan and Chongqing, the remotely sensed Normalized Difference Water In- dex (NDWI) for the summers of 2001―2006 were calculated based on 8-day composite MODIS products, which were further used to construct a new water index (Normalized Difference Water Deviation Index, NDWDI) to examine the sensitivity of remote sensing in the Drought. The study showed that the NDWDI is more sensitive to regional drought than other absolute-soil-moisture-based indices. With the new index, the study extracted the spatial-temporal characteristics of the 2006 Drought, and explored its developing and withdrawing processes, which agreed with related statistics. Compared with ground method of drought observation, the NDWDI-based remote sensing solution of this paper is more pref- erable and practicable in that the local soil properties of water consumption and supply are implicitly taken into account, and the spatial representativity limit of ground observation is circumvented to a degree as satellite remotely senses the earth surface in a way of two-dimensional pixel matrix. So, the NDWDI-based method can be used to monitor regional soil water stress situation more practically and efficiently.

关键词： Sichuan Basin drought Normalized Difference Water Deviation Index response of remote sensing regional scale

Synthesize TiO_2 microspheres self-assembled from nanorods via hydrothermal treatment

在线全文

学校读者我要写书评

暂无评论

Science china Chemistry 2007年第2期50卷 175-178页

作者： ZHANG YiBing1,2,FENG XinJian3 & JIANG Lei2,3 1 Shangrao Teachers’ College,Shangrao 334001,china 2 national center for Nanoscience and Nanotechnology,beijing 100080,china 3 Institute of Chemistry,Chinese Academy of Sciences,beijing 100080,china Shangrao Teachers’ College Shangrao China national center for Nanoscience and Nanotechnology Beijing China Institute of Chemistry Chinese Academy of Sciences Beijing China

The TiO2 microspheres were deposited on the glass substrates under certain conditions via hydro-thermal reaction using 0.15 mol·L?1 TiCl3 saturated NaCl aqueous solution adding urea as an additive. The TiO2 is characterized rutile by results of SEM,TEM and XRD techniques,the TiO2 microspheres are large scale assembled from TiO2 nanorods. The affections on the products by the factors of the con-tents of urea being an additive(the key techniques) ,the reaction temperature,the reaction time and the concentration of TiCl3 were studied. The optimum condition was found,and the mechanism of reac-tions was discussed also.

关键词： TiO2 self-assembly nanorods microsphere hydrothermal reaction

Distribution,formation and evolution of sand ridges on the East china Sea shelf

在线全文

学校读者我要写书评

暂无评论

Science china(Technological Sciences) 2010年第3期53卷 822-828页

作者： ZHAO RenBao 1,2,SUN HaiTao 3,WU YaSheng 3 &ZHAO ChuanFeng 1,2 1MOE Key Laboratory of Petroleum Engineering,china University of Petroleum,beijing 102249,china 2 Enhanced Oil Recovering research center,china University of Petroleum,beijing 102249,china 3Faculty of Natural Resource&Information Technology,china University of Petroleum,beijing 102249,china MOE Key Laboratory of Petroleum Engineering China University of Petroleum Beijing China Enhanced Oil Recovering research center China University of Petroleum Beijing China Faculty of Natural Resource & Information Technology China University of Petroleum Beijing China

Influence of CO2 corrosion on reservoir mineralogical composition,pore structure and their mechanical characteristics was studied using XRD,SEM,rock tri-axial machine and core flow experimental *** was found that the corrosion effect was mainly attributed to rock texture and structure,fluid composition and external dynamical conditions in the experimental *** cores with bedding structures,their bedding surfaces were the preferential corrosion regions,because micro-cracks would evolve at these surfaces in the pressure-releasing ***,for cores with massive structures controlled by stable water environment,the CO2 corrosion would result in pore enlargement and secondary pore *** gas velocity from outlet showed sharp increase in the injection process of CO2-H2O *** could be explained by two changes caused by *** was the opening and closure of *** other was particle *** the corrosion time increased,both tensile strength and compressive strength decreased,which confirmed decrease of cementation *** should also be noted that permeability increase and micro-cracks generation would pose damage to the capacity of CO2 geological storage.

关键词： carbon dioxide geological storage mineralization enhanced oil recovery corrosion

Radiometric cross-calibration of the CBERS-02 CCD camera with the TERRA MODIS

在线全文

学校读者我要写书评

暂无评论

Science china(Technological Sciences) 2005年第S2期48卷 44-60页

作者： LI Xiaoying1,2,3, GU Xingfa1,3,4, MIN Xiangjun5, YU Tao1,3, FU Qiaoyan5, ZHANG Yong1,2,3 & LI Xiaowen1,3 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 100039, 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. china center for Resource Satellite Data and Application, beijing 100830, china State Key Laboratory of Remote Sensing Science Beijing Normal University Chinese Academy of Sciences Beijing 100101 China Graduate University Chinese Academy of Sciences Beijing 100039 China center for national Spaceborne Demonstration Beijing 100101 China Institut national de la Recherche Agronomique Climat Sol Environnement 84914 Avignon France china center for Resource Satellite Data and Application Beijing 100830 China

For the application of the CCD camera, the most important payload on CBERS-02, the key is to provide long-term stable radiometric calibration coefficients. Although the vicarious calibration had been proved successful, it had its limitations such as test site requirement and unsuitable for historical data. Cross-calibration is one of the alternative methods, but it needs synchro surface spectrum to achieve spectral band matching factors. Our effort is to probe the influences on these factors. Simulations with a lot of surface spectrum showed that the factors changed with the viewing geometry, atmospheric condition and surface targets. However, simulating with the same viewing geometry and atmospheric condition, the spectral band matching factors of the same or similar surface targets’ spectrum acquired from different dates and different places would like to be consistent to each other within 1%―5%. Thus, the synchro measurement data can be substituted by the same or similar target from other source. Based on this method, using the MODIS as the reference, the cross-calibration was performed for CCD camera. The research demonstrated that the traditional method with single calibration site was inappropriate for CCD camera, since the offsets for its four spectral bands were not zeros. With four calibration sites, these offsets were obtained. And the camera was detected to degrade with dates based on four times of cross-calibrations.

关键词： CBERS-02 CCD camera cross-calibration the spectral band matching factors.