检索结果-南通市图书馆

A fusion algorithm for remote sensing images based on nonsubsampled pyramids and bidimensional empirical decomposition

引用

science china(Technological sciences) 2010年第S1期53卷 196-204页

作者： ZHANG XiaoDong 1,WANG WenBo 2.WANG DiFeng 3.& ZHANG Yu 4 1 state key {2. of Information Engineering in Surveying,Mapping and remote sensing,Wuhan University,Wuhan 43.079,china 2.College of sciences,Wuhan University of science and Technology,Wuhan 43.065,china 3.1} key {2. of Satellite Ocean Environment Dynamics,Second Institute of Oceanography,state Oceanic Administration,Hangzhou 3.0012.china 4 Spatial Information Technology Application Research Institute,Changjiang River Scientific Research Institute,Wuhan 43.010,china Wuhan Univ State Key Lab Informat Engn Surveying Mapping & R Wuhan 430079 Peoples R China Wuhan Univ Sci & Technol Coll Sci Wuhan 430065 Peoples R China state Ocean Adm Inst Oceanog 2 State Key Lab Satellite Ocean Environm Dynam Hangzhou 310012 Zhejiang Peoples R China Changjiang River Sci Res Inst Spatial Informat Technol Applicat Res Inst Wuhan 430010 Peoples R China

In order to improve the quality of remote sensing image fusion,a new method combining nonsubsampled Laplacian pyramid (NLP)and bidimensional empirical mode decomposition(BEMD)is ***,the high resolution panchromatic image (PAN)is decomposed using NLP until the approximate component and the low resolution multispectral image(MS)contain features with a similar ***,the approximation component and the MS are decomposed by BEMD,resulting in a number of bidimensional intrinsic mode functions(BIMF)and a residue *** instantaneous frequency is computed in 4 directions of the *** the positive or negative coefficients in the corresponding position,a weighted algorithm is designed for fusing the high frequency details using the instantaneous frequency and the coefficient absolute value of the BIMFs as fusion *** fused image is then obtained through inverse BEMD and *** results have illustrated the advantage of this method over the IHS,DWT andà-Trous wavelet in both spectral and spatial detail qualities.

关键词： bidimensional empirical mode decomposition nonsubsampled pyramid instantaneous frequency remote sensing image fusion

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Magnetic mineralogy of the Hongqiling Cu-Ni sulphide deposit: Implications for ore genesis

引用

Progress in Natural science:Materials International 2007年第10期17卷 1192-1198页

作者： Xi Aihua1,2. Ge Yuhui1, Cai Yuanfeng2.and Zhang Xuefeng3.1. Faculty of Resources & Environment, Southwest Petroleum University, Chengdu 610500, china 2. state {2. laboratory for Endogenic Metal Deposit Research, Nanjing University, Nanjing 2.0093. china 3. Department of Natural Resources & Technology Information, china University of Petroleum, beijing 102.49, china) Faculty of Resources & Environment Southwest Petroleum University Chengdu 610500 China state key {2. for Endogenic Metal Deposit Research Nanjing University Nanjing 210093 China Department of Natural Resources & Technology Information China University of Petroleum Beijing 102249 China

Pyrrhotite is one of the common ore minerals in Cu-Ni sulphide deposits, but only monoclinic pyrrhotite is ferromagnetic at room temperature. X-ray and EPA analyses reveal that most pyrrhotite forming sideronitic texture in the Hongqiling Cu-Ni sulphide deposit is monoclinic, but that in the massive ore is a mixture of monoclinic and hexagonal pyrrhotites. Differential thermal and magnetic- thermogravimetric analyses of massive ore indicate a magnetic transition and heat absorption at 3.0}℃, suggesting that this temperature is the thermomagnetic and phase transition point of pyrrhotite. For massive pyrrhotite ores heated at 400oC for 3. h and then quenched by cool water, the monoclinic pyrrhotite (mpo) transforms completely into the hexagonal pyrrhotite (hpo). However, all the pyrrhotites resulting from slow cooling of the sample in air are mpo. These results indicate that transformation between hpo and mpo depends upon the cooling rate. Therefore, massive ores in this deposit might have been formed via rapid cooling of ore melts. On the other hand, it is significant to study the effect of the ratio of the magnetite in total ores on the genesis of magmatic Cu-Ni suphide deposits.

关键词： pyrrhotite magnetite genesis of Cu-Ni sulphide deposit Hongqiling.

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Mechanism for calcite dissolution and its contribution to development of reservoir porosity and permeability in the Kela 2.gas field,Tarim Basin,china

引用

science china Earth sciences 2008年第4期51卷 567-578页

作者： YU BingSong1,3. DONG HailLiang2.3.& RUAN Zhuang1,3.1 state key {2. of Geological Processes and Mineral Resources, china University of Geosciences, beijing 100083. china 2.Department of Geology, Miami University,Oxford, OH 45056, USA 3.Geomicrobiology {2., china University of Geosciences, beijing, 100083. china state key {2. of Geological Processes and Mineral Resources China University of Geosciences Beijing 100083 China Department of Geology Miami University Oxford OH 45056 USA Geomicrobiology laboratory China University of Geoscien

This study is undertaken to understand how calcite precipitation and dissolution contributes to depth-related changes in porosity and permeability of gas-bearing sandstone reservoirs in the Kela 2.gas field of the Tarim Basin, Northwestern china. Sandstone samples and pore water samples are col-lected from well KL2.1 in the Tarim Basin. Vertical profiles of porosity, permeability, pore water chem-istry, and the relative volume abundance of calcite/dolomite are constructed from 3.00 to 4000 m below the ground surface within major oil and gas reservoir rocks. Porosity and permeability values are in-versely correlated with the calcite abundance, indicating that calcite dissolution and precipitation may be controlling porosity and permeability of the reservoir rocks. Pore water chemistry exhibits a sys-tematic variation from the Na2.O4 type at the shallow depth (3.00-3.3. m), to the NaHCO3.type at the intermediate depth (3.3.―3.95 m),and to the CaCl2.type at the greater depth (3.2.―3.3. m). The geochemical factors that control the calcite solubility include pH, temperature, pressure, Ca2. concen-tration, the total inorganic carbon concentration (ΣCO2., and the type of pore water. Thermodynamic phase equilibrium and mass conservation laws are applied to calculate the calcite saturation state as a function of a few {2. parameters. The model calculation illustrates that the calcite solubility is strongly dependent on the chemical composition of pore water, mainly the concentration difference between the total dissolved inorganic carbon and dissolved calcium concentration (i.e., [ΣCO2. -[Ca2.]). In the Na2.O4 water at the shallow depth, this index is close to 0, pore water is near the calcite solubility. Calcite does not dissolve or precipitate in significant quantities. In the NaHCO3.water at the intermedi-ate depth, this index is greater than 0, and pore water is supersaturated with respect to calcite. Massive calcite precipitation was observed at this depth interval and

关键词： calcite dissolution porosity thermodynamic Tarim Basin

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Surface roughness and removal rate in magnetorheological finishing of a subsurface damage free surface

引用

Progress in Natural science:Materials International 2005年第6期15卷 538-544页

作者： CHENG Haobo1*, WANG Yingwei2. FENG Zhijing1 and CHENG Kai3.1. state key {2. of Tribiology, Tsinghua University, beijing 100084, china 2. Department of Material sciences, Changchun University of science and Technology, Changchun 13.02., china 3. Faculty of Information and Engineering Systems, City Campus, Leeds LS1 3.E, UK) state key {2. of Tribiology Tsinghua University Beijing 100084 China Department of Material sciences Changchun University of Science and Technology Changchun 130021 China Faculty of Information and Engineering Systems City Campus Leeds LS1 3HE UK

Based on computer-controlled optical surfacing, a new technique called magnetorheological finishing (MRF), is presented. The new technique combines the features of conventional loose abrasive machining with a wheel shaped polishing tool. The tool incorporates a host of features and has unprecedented fabricating versatility. The pre-polishing and fine polishing processes can be performed only by adjusting different parameters. The material removal function is studied theoretically and the results of simulation present a Gaussian distribution feature. Based on the established theoretical model, material removal rate experiments involving a parabolic mirror are designed and carried out to determine the effect of controllable parameters on size of the gap between the workpiece and the polishing wheel, rotating speed of the polishing wheel, concentration of volume fraction of non-magnetic particles and polishing time. Further experiments are carried out on the surface microstructure of the workpiece, the final surface roughness with an initial value of 10.98 nm reaches 1.2. nm root mean square (RMS) after 2. min of polishing. The subsurface damage experiment and the atomic force microscopy (AFM) measurement on the polished surface can also verify the feasibility of the MRF technique.

关键词： magnetorheological finishing surface roughness computer controlled optical surfacing subsurface damage removal function.

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

In flight MTF monitoring and compensation for CCD camera on CBERS-02

引用

science china(Technological sciences) 2005年第S2期48卷 29-43页

作者： GU Xingfa1,2.3. LI Xiaoying1,2.4, MIN Xiangjun5, YU Tao1,2. SUN Jijuan5, ZENG Yong1,2.4, XU Hua1,2.& GUO Ding2.6 1. state key {2. 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. The Center for National Spaceborne Demonstration, beijing 100101, china 3. Institut National de la Recherche Agronomique, Climat Sol Environnement, 84914 Avignon, France 4. Graduate University of Chinese Academy of sciences, beijing 10003., china 5. china Center for Resource Satellite Data and Application, beijing 10083., china 6. University of Electronic science and Technology of china, Chengdu 610054, china state key {2. of {3. sensing science Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University 100101 Beijing China The Center for National Spaceborne Demonstration 100101 Beijing China Institut National de la Recherche Agronomique Climat Sol Environnement 84914 Avignon France Graduate University of Chinese Academy of sciences 100039 Beijing China china Center for Resource Satellite Data and Application 100830 Beijing China University of Electronic science and Technology of china 610054 Chengdu China

In this article, the approach of simulating ideal tarp scene was proposed to determine the MTF for CCD camera on CBERS-02. The MTF acquired from this technique was compared to those from some common methods. MTFs achieved from different approaches were employed to compensate the CCD images based on three restoration algorithms: the iterative method, the Wiener filter and the modified inverse filter (MIF). The two-dimensional MTF was established with the value at frequency 0.5 for 45° directional MTF as the value at its four corners. This article addressed the variations of the restored CCD images with different techniques of constructing two-dimensional MTF, restoring algorithms and determining the in-flight MTFs. Results showed images restored with the MTF determined from the technique of simulating ideal tarp scene represent the real scene best. And the restoration technique based on the MIF would produce better restored images than the other two techniques. This research also demonstrated that the two-dimensional MTF used for restoration should be interpolated under the control of the MTF for 45° axis, rather than by multiplying the cross-orbit MTF with along-orbit MTF.

关键词： CBERS-02 CCD MTF the technique of simulating ideal tarp scene.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Estimation methods of eco-environmental water requirements: Case study

引用

science china Earth sciences 2005年第8期48卷 1280-1292页

作者： YANG Zhifeng1,2. CUI Baoshan1 & LIU Jingling 1. School of Environment, beijing Normal University, beijing 100875,{2. 2. state key Joint laboratory of Environmental Simulation and Pollution Control, beijing 100875,{2. 1. School of Environment Beijing Normal University 100875 Beijing China 2. state key Joint {2. of Environmental Simulation and Pollution Control 100875 Beijing China

Supplying water to the ecological environment with certain quantity and quality is significant for the protection of diversity and the realization of sustainable development. The conception and connotation of eco-environmental water requirements, including the definition of the conception, the composition and characteristics of eco-environmental water requirements, are evaluated in this paper. The classification and estimation methods of eco-environmental water requirements are then proposed. On the basis of the study on the Huang-Huai-Hai Area, the present water use, the minimum and suitable water requirement are estimated and the cor-responding water shortage is also calculated. According to the interrelated programs, the eco-environmental water requirements in the coming years (2.10, 2.3., 2.50) are estimated. The result indicates that the minimum and suitable eco-environmental water requirements fluc-tuate with the differences of function setting and the referential standard of water resources, and so as the water shortage. Moreover, the study indicates that the minimum eco-environmental water requirement of the study area ranges from 2.84×1010m3.to 1.02.1011m3. the suitable water requirement ranges from 6.45×1010m3.to 1.78×1011m3. the water shortage ranges from 9.1×109m3.to 2.16×1010m3.under the minimum water requirement, and it is from 3.07×1010m3.to 7.53.1010m3.under the suitable water requirement. According to the different values of the water shortage, the water priority can be allocated. The ranges of the eco-environmental water re-quirements in the three coming years (2.10, 2.3., 2.50) are 4.49×1010m3.1.73.1011m3. 5.99×10m3.2.09×1011m3. and 7.44×1010m3.2.52.1011m3. respectively.

关键词： eco-environmental water requirements, assessment methods, Huang-Huai-Hai area.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A heuristic path-estimating algorithm for large-scale real-time traffic information calculating

引用

science china(Technological sciences) 2008年第S1期51卷 165-174页

作者： L WeiFeng1,ZHU TongYu1,WU DongDong2.DAI Hong3.& HUANG Jian1 1 state key {2. for Software Development Environment,Beihang University,beijing 100083.china 2.beijing Transportation Information Center,beijing 100055,china 3.College of Arts & science,beijing Union University,beijing 100083.china 1. state key {2. for Software Development Environment Beihang University Beijing 100083 China 2. beijing Transportation Information Center Beijing 100055 China 3. College of Arts & science Beijing Union University Beijing 100083 China

As the original Global Position System (GPS) data in Floating Car Data have the accuracy problem,this paper proposes a heuristic path-estimating algorithm for large-scale real-time traffic information calculating. It uses the heuristic search method,imports the restriction with geometric operation,and makes comparison between the vectors composed of the vehicular GPS points and the special road network model to search the set of vehicular traveling route candidates. Finally,it chooses the most optimal one according to weight. Experimental results indicate that the algorithm has considerable efficiency in accuracy (over 92.7%) and com-putational speed (max 8000 GPS records per second) when handling the GPS tracking data whose sampling rate is larger than 1 min even under complex road network conditions.

关键词： path-estimating floating car data (FCD) road network vector GPS

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The correlation of multi-angle thermal infrared data and the choice of optimal view angles

引用

science china Earth sciences 2004年第6期47卷 570-576页

作者： FAN Wenjie1 & XU Xiru1,2.1.Institute of remote sensing and GIS of Peking University,{2. 100871,china 2.Center of remote sensing and GIS of {2. Normal University,{2. 100875,china 1. Institute of remote sensing and GIS of Peking University 100871 Beijing China 2. Center of remote sensing and GIS of {2. Normal University 100875 Beijing China

Based on the matrix formula of thermal infrared radiant system, the components temperature can be retrieved by the inversive matrix. Around the stability problem of retrieved result, the research work we did was focused on (i) the correlation of (wk,j) which is the key to affect the retrieval accuracy, (ii) a general method which can help us find the number of retrievable parameters and evaluate the retrieval error before its performance, (iii) the choice of “optimal viewing angle group” based on the formula of absolute error propagation. The row winter wheat field was chosen as an example. The results can provide a theoretical basis for multi-angle thermal infrared remote {2. and components temperature retrieval.

关键词： components temperature retrieval, correlation, number of retrievable parameters, optimal viewing angle group.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Investigation of Al-based Alloys for Brazing SiC_p/Al Composites

引用

稀有金属材料与工程 2011年第S3期40卷 132-135页

作者： Wu Mao1,2. Chang Lingling2. Peng Zirong2. Feng Zelong2. Yong Weina2. Wang Wei2. He Xinbo1,2. Qu Xuanhui1,2.1state key {2. for Advanced Metals and Materials, University of science and Technology beijing 100083.{13. 2.beijing key {2. for Powder Metallurgy and Particulate Materials, University of science and Technology beijing, beijing 100083.{13. Univ Sci & Technol beijing State Key Lab Adv Met & Mat Beijing 100083 Peoples R China Univ Sci & Technol beijing Beijing Key Lab Powder Met & Particulate Mat Beijing 100083 Peoples R China

The brazing of SiCp/Al composites is limited owing to the unavailability of suitable commercial intermediate temperature brazes. Adding a third constituent of copper to aluminum-silicon brazing alloy can depress the melting point sharply. While, it generates a large volume fraction of the hard Al2.u intermetallic compounds (IMCs), which makes the alloy brittle and reduces its corrosion resistance. A quaternary addition of nickel that partly substitute for copper can refine grain size significantly, improve the mechanical properties, and without altering the melting range of aluminum-silicon-copper alloy. Al-Cu-Ni-Si braze alloy has been prepared and a fluxless process has been employed to braze SiCp/Al composites that leads to a good bonding strength of brazing joint.

关键词： SiCp/Al composites Al-based brazes brazing intermetallic compounds (IMCs)

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Sediment transport capacity of hyperconcentrated flow

引用

science china(Physics,Mechanics & Astronomy) 2008年第8期51卷 961-975页

作者： SHU AnPing1,2.& FEI XiangJun2.1 School of Environment & key {3. of Water and Sediment {2.s,Ministry of Education,beijing Normal University,beijing 100875,china 2.state key {3. of Hydro{2. and Engineering,Tsinghua University,beijing 100084,china School of Environment & key laboratory of Water and Sediment {2.s Ministry of Education Beijing Normal University Beijing 100875 China state key {2. of Hydro{3. and Engineering Tsinghua University Beijing 100084 China

As one of the most important components of river mechanics,sediment transport capacity of sediment-laden flows has attracted much attention from many researchers working on river mechanics and hydraulic engineering. Based on the time-averaged equation for a turbulent energy equilibrium in solid and liquid two-phase flow,an expression for the efficiency coefficient of suspended load movement was derived for the two-dimensional,steady,uniform,fully-developed turbulent flow. A new structural expression of sediment transport capacity was achieved. Using 115 runs of flume experimental data,which were obtained through two kinds of sediment transport experiments in the state of equilibrium,in combination with the basic rheological and sediment transporting characteristics of hyperconcentrated flow,the main parameters in the structural expression of sediment transport capacity were calibrated,and a new formula of sediment transport capacity for hyperconcentrated flow was developed. A large amount of field data from the Yellow River,Wuding River,and Yangtze River,etc. were adopted to verify the new formula and good agreement was obtained. These results above contribute to an improved theoretical system of river mechanics and a reliable tool for management of rivers carrying high concentration of sediments.

关键词： hyperconcentrated flow turbulent energy equilibrium efficiency coefficient sediment transport capacity

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：