检索结果-南通市图书馆

Phase relationship of complex multi-component system in chromate cleaner production

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2007年第7期17卷 845-850页

作者： Ge Xinlei~1 Wang Xidong~(1,3**) Zheng Shili~2.Zhang Mei~1 Zhang Yi~2.(1.Department of Physical Chemistry,university of Science and technology {2.,{2. 100083,china 2.institute of Process Engineering,Chinese Academy of Sciences,{2. 100080,china 3.College of Engineering,Peking university,{2. 100871,china) [a]Department of Physical Chemistry University of Science and Technology Beijing Beijing China [b]College of Engineering Peking University Beijing China [c]institute of Process Engineering Chinese Academy of Sciences Beijing China

The phase relationships of the complex multi-component systems in the liquid-phase oxidization and separation process related with the chromate cleaner production are investigated theoretically and *** phase diagram of main system Fe- Cr2.4-KOH-O2.f oxidization process and the relationship of its standard Gibbs free energy change with temperature are calculated.A se- ries of phase diagrams of the separation process at different temperatures,such as K（Na）OH-K（Na）2.rO4-H2.,KOH-KAlO2.H2., K（Na）OH-K（Na）2.O3-H2.,K（Na）OH-K（Na）HCO3-H2. and K（Na）HCO3-K（Na）2.rO4-H2. have also been *** ex- periments are carried out to verify the calculated *** results showed that the sub-molten salt media are suitable for the oxidization and separation processes;FeCr2.4can be oxidized across a wide range of temperature;K（Na）2.rO4can be separated from K（Na）AlO2.ystem at appropriate temperature and proper concentration;the crystallization of carbonate is easier than that of K（Na）2.rO4.

关键词： chromite chromate system thermodynamics calculation phase diagram

Global convergence property of s-dependent GFR conjugate gradient method

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1998年第23期43卷 1959-1965页

作者： WANG Changyu 1,2.and ZHANG Yuzhong\+1 1. institute of Operations research in Qufu Normal {2., Qufu 2.3165, china 2. institute of Applied Mathematics, Chinese Academy of Sciences, beijing 100080, china institute of Operations research Qufu Normal University Qufu China institute of Applied Mathematics Chinese Academy of Sciences Beijing China

An \%S\%_dependent GFR method and a generalized conjugate gradient method are designed. Two estimated values of upper bounds for the ratio of β k to β FR k are given. The two convergence theorems are proved. The global convergent properties of \%s\%_dependent GFR method are obtained adopting several choice strategies of steplength and some results in recent literature are extended.

关键词： steplength linear search global convergence conjugate gradient.

Prediction of Dynamic Wellbore Pressure in Gasified Fluid Drilling

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2007年第4期4卷 66-73页

作者： Wang Zhiming1,Ping Liqiu2.and Zou Ke2.(1. School of Petroleum Engineering,Petroleum university of china,{2. 102.49,china) (2. institute of Drilling Engineering technology,CNPC,{2. 100097,china) Petr Univ china Sch Petr Engn Beijing 102249 Peoples R China CNPC Inst Drilling Engn Technol Beijing 100097 Peoples R China

The basis of designing gasified drilling is to understand the behavior of gas/liquid two-phase flow in the wellbore. The equations of mass and momentum conservation and equation of fluid flow in porous media were used to establish a dynamic model to predict wellbore pressure according to the study results of Ansari and Beggs-Brill on gas-liquid two-phase flow. The dynamic model was solved by the finite difference approach combined with the mechanistic steady state model. The mechanistic dynamic model was numerically implemented into a FORTRAN 90 computer program and could simulate the coupled flow of fluid in wellbore and reservoir. The dynamic model revealed the effects of wellhead back pressure and injection rate of gas/liquid on bottomhole pressure. The model was validated against full-scale experimental data,and its 5.0% of average relative error could satisfy the accuracy requirements in engineering design.

关键词： Gasified fluid drilling dynamic model pressure prediction model validation

A Cold Adhesion for Self-fused Alloy Coat by High Frequency Induction

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

材料热处理学报 2004年第5B期25卷 1316-1320页

作者： ZHANGZeng-zhi AIBo researchinstituteofEcofogicalandFunctionalMaterial ChinaUniversityofMiningandTechnology（Beijing）.BeijingChina

In this study, a method to prepare self-fused alloy coat, which started with a cold adhesion precoating and then induction fusing plus, is presented. It also intended to analyze the mechanism, microstructure and anitwear ability of the coat. The workpiece was precoated with Ni60 powder through an adhesion agent. The oven-dried precoat was then heated by a high frequency induction generated by 100kw power with a frequency of 2.0kHz. The technological parameters of the method were determined through analysis of the thermal magnetism, thermal resistivity and anti-induction mechanism. By comparing the microstrucrures and properties of the coat produced by cold adhesion, thermal spraying and laser refusing, it is concluded that: (1) One side of the workpiece should be preheated to 2.0℃ before induction fusion, and the range of induction frequency should be 2.0～2.0kHz. (2. The microstrucrure of the coat by cold adhesion is superior to that by thermal spraying, but the particle size range should be 0.047～0.044mm (2.0～32. meshes) (3) The corrosion resistance of Ni60 coat by cold adhesion is better than that by thermal spraying, and the cold adhesion is the best method to prepare the antiwear coat.

关键词：冷附着自熔融合金高频感应 Ni60

3D building modeling,organization and application in digital city system

在线全文

学校读者我要写书评

暂无评论

中国科学：技术科学英文版 2010年第S1期53卷 134-142页

作者： YANG Xue 1,WENG JingNong 1,2.XIA YuBin 2.WU Lun 3 & SUI ZhengWei 3 1 College of Software,Beihang university,beijing 100191,{2. 2.College of Computer,Beihang university,beijing 100191,{2. 3 institute of Remote Sensing and gis,Peking university,beijing 100871,{2. Beihang Univ Coll Software Beijing 100191 Peoples R China Beihang Univ Coll Comp Beijing 100191 Peoples R China Peking Univ Inst Remote Sensing & GIS Beijing 100871 Peoples R China

The real world is a three-dimensional(3D)space requiring that 3D geospatial information applications be developed in alignment with the observer’s visual and perceptive ***,3D building model data are required in a wide range of areas such as urban planning,environmental protection,real estate management and emergency *** the same time,the development of Web service[LU1]technologies allows the possibility of the widely distributed 3D geospatial data on the web.3D city building model with its related information is an important part in the construction of a digital city system,and has become a staple resource on the web *** view of the hierarchical representation of a 3D building model,an abstract of a 3D building model based on structure details is studied,and a novel representation approach named 3D transparent building hierarchical model is presented in this *** approach fully uses both the existing 3D modeling technologies and CAD constructing mapping *** the spatial relationship description,structural components inside a building can be represented and integrated as hierarchical models in a unified 3D *** addition,based on the characteristics of the 3D building model data,a service-oriented architecture and Web service technologies for 3D city building models are *** aim of the approach is that 3D city building models can be used as a kind of data resource service on the web,and can also exist independently in various different web applications.

关键词： 3D modeling 3D transparent building hierarchical models china Star web services

A new navigation approach of terrain contour matching based on 3-D terrain reconstruction from onboard image sequence

在线全文

学校读者我要写书评

暂无评论

Science china(Technological Sciences) 2010年第5期53卷 1176-1183页

作者： LI LiChun1,2.YU QiFeng2.SHANG Yang2.YUAN Yun2.LU HongWei3 & LIU XiaoLin4 1 beijing Aerospace Control Center,beijing 100094,{2. 2.College of Aerospace and Material Engineering,National university of Defense technology,Changsha 410073,{2. 3 Equipment research institute of PLA’s Second Artillery,beijing 100085,{2. 4 College of Mechatronic Engineering and Automation,National university of Defense technology,Changsha 410073,{2. 1. beijing Aerospace Control Center Beijing 100094 China2. College of Aerospace and Material Engineering National University of Defense Technology Changsha 410073 China3. Equipment Research Institute of PLA’s Second Artillery Beijing 100085 China4. College of Mechatronic Engineering and Automation National University of Defense Technology Changsha 410073 China

This article presents a passive navigation method of terrain contour matching by reconstructing the 3-D terrain from the image sequence(acquired by the onboard camera).To achieve automation and simultaneity of the image sequence processing for navigation,a correspondence registration method based on control points tracking is proposed which tracks the sparse control points through the whole image sequence and uses them as correspondence in the relation geometry ***,a key frame selection method based on the images overlapping ratio and intersecting angles is explored,thereafter the requirement for the camera system configuration is *** proposed method also includes an optimal local homography estimating algorithm according to the control points,which helps correctly predict points to be matched and their speed ***,the real-time 3-D terrain of the trajectory thus reconstructed is matched with the referenced terrain map,and the result of which provides navigating *** digital simulation experiment and the real image based experiment have verified the proposed method.

关键词： terrain contour matching vision-based navigation 3-D reconstruction control points key frame registration optimal local homography

Digital close-range photogrammetric application to small-scale physical simulation experiment

在线全文

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 2011年第S3期21卷 681-685页

作者： LI Chun-yi1, CUI Xi-min2. YU Yi-ju3 1. School of Surveying and Landing Information Engineering, Henan Polytechnic university, Jiaozuo 454003, china 2. College of Geoscience and Surveying Engineering, china university of mining and technology, beijing 100083, china 3. Surveying and Mapping Press, beijing 100045, china [a] School of Surveying and Landing Information Engineering Henan Polytechnic University Jiaozuo 454003 China [b] College of Geoscience and Surveying Engineering China University of Mining and Technology Beijing 100083 China [c] Surveying and Mapping Press Beijing 100045 China

In order to research the possibility of digital close-range photogrammetric surveying in small scale physical simulation experiment, physical model coinciding with engineering practice was constructed based on similar theory. The datum processing method and surveying precision of digital close-range photogrammetric were analyzed. And the function relationship between overburden subsidence factor qr and the ratio z/H of stratum horizon z and {2. depth H was researched. The results show that surveying points position mean error along horizontal direction is ±0.131 mm and vertical direction is ±0.192.mm. Therefore, multi-taking station cross direction digital close-range photogrammetric can completely satisfy the precision need of physical simulation experiment. And the empirical formula can be utilized to represent evolution law of stratum subsidence factor.

关键词： close-range photogrammetric physical simulation light-rays adjustment surveying precision subsidence factor

Polynomial analysis of canopy spectra and biochemical component content inversion

在线全文

学校读者我要写书评

暂无评论

Science china Earth Sciences 2005年第10期48卷 1780-1791页

作者： YAN Chunyan1, LIU Qiang1, NIU Zheng1, WANG Jihua2. HUANG Wenjiang2.& LIU Liangyun 2.1. State Key Laboratory of Remote Sensing Science, Jointly Sponsored by the institute of Remote Sensing Applications of Chinese Academy of Sciences and beijing Normal {2., beijing 100101, china 2. National Engineering research Center for Information technology in Agriculture, beijing 100089, 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 {2. beijing china National Engineering research Center for Information technology in Agriculture {2. china

A polynomial expression model was developed in this paper to describe directional canopy spectra, and the decomposition of the polynomial expression was used as a tool for re-trieving biochemical component content from canopy multi-angle spectra. First, the basic formula of the polynomial expression was introduced and the physical meaning of its terms and coeffi-cients was discussed. Based on this analysis, a complete polynomial expression model and its decomposition method were given. By decomposing the canopy spectra simulated with SAILH model, it shows that the polynomial expression can not only fit well the canopy spectra, but also show the contribution of every order scattering to the whole reflectance. Taking the first scattering coefficients a10 and a01 for example, the test results show that the polynomial coefficients reflect very well the hot spot phenomenon and the effects of viewing angles, LAI and leaf inclination angle on canopy spectra. By coupling the polynomial expression with leaf model PROSPECT, a canopy biochemical component content inversion model was given. In the simulated test, the canopy multi-angle spectra were simulated by two different models, SAILH and 4-SCALE re-spectively, then the biochemical component content was retrieved by inverting the coupled polynomial expression + PROSPECT model. Results of the simulated test are promising, and when applying the algorithm to measured corn canopy multi-angle spectra, we also get relatively accurate chlorophyll content. It shows that the polynomial analysis provides a new method to get biochemical component content independent of any specific canopy model.

关键词： polynomial expression, canopy spectra, decomposition, biochemical component content, inversion.

Liquid propellant analogy technique in dynamic modeling of launch vehicle

在线全文

学校读者我要写书评

暂无评论

Science china(Technological Sciences) 2010年第8期53卷 2102-2110页

作者： PAN ZhongWen 1,2.,XING YuFeng 1 ,ZHU LiWen 2.,DONG Kai 2.&SUN Mu 2.1Solid Mechanics research Center,beijing {2. of Aeronautics and Astronautics,beijing 100191,china 2.beijing Astronautics Systems Engineering institute,beijing 100076,china 1. Solid Mechanics research Center Beijing University of Aeronautics and Astronautics Beijing 100191 China2. Beijing Astronautics Systems Engineering Institute Beijing 100076 China

The coupling effects among lateral mode,longitudinal mode and torsional mode of a launch vehicle cannot be taken into account in traditional dynamic analysis using lateral beam model and longitudinal spring-mass model *** deal with the problem,propellant analogy methods based on beam model are proposed and coupled mass-matrix of liquid propellant is constructed through additional mass in the present *** an integrated model of launch vehicle for free vibration analysis is established,by which research on the interactions between longitudinal and lateral modes,longitudinal and torsional modes of the launch vehicle can be *** examples for tandem tanks validate the present method and its necessity.

关键词： dynamic characteristics coupled mass integrative modeling propellant analogy