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measuring PRECISION OF INDUCED POLARIZATION METHOD

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中国有色金属学会会刊：英文版 1994年第4期4卷 1-6页

作者： He,Jishan(Central South University of Technology,Changsha 410083)

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关键词： measuring precision induced polarization method (IP) dual-frequency IP frequency domain IP time IP

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Multi-parameter optimization of machining impeller surface based on the on-machine measuring technique

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Chinese Journal of Aeronautics 2019年第8期32卷 2000-2008页

作者： Gang WANG Wen-long LI Fan RAO Zheng-rong HE Zhou-ping YIN State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China China National South Aviation Industry Co. LtdZhuzhou 412002China

Selecting the optimal machining parameters for impeller surface is a challenging task in the automatic manufacturing industry, due to its free-form surface and deep-crooked flow *** experimental methods require lots of machining experiments and off-line tests, which may lead to high machining cost and low efficiency. This paper proposes a novel method of machining parameters optimization for an impeller based on the on-machine measuring technique. The absolute average error and standard deviation of the measured points are used to define the grey relational grade for reconstructing the objective function, and the complex problem of multi-objective optimization is simplified into a problem of single-objective optimization. Then, by comparing the values of the defined grey relational grade in a designed orthogonal experiment, the optimal combination of the machining parameters is obtained. The experiment-solving process of the objective function corresponds to the minimization of the used errors, which is advantageous to reducing the machining error. The proposed method is efficient and low-cost, since it does not require re-clamping the workpiece for off-line tests. Its effectiveness is verified by an on-machine inspection experiment of the impeller blade.

关键词： Grey relational grade Impeller surface Multi-parameters optimization On-machine measuring Orthogonal experiment

Comparative experimental study on several methods for measuring elastic wave velocities in rocks at high pressure

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Science China Earth Sciences 2002年第11期45卷 990-998页

作者：谢鸿森周文戈刘永刚郭捷侯渭赵志丹 Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China Petrology Laboratory Department of Geology and Mineral Resources China University of Geosciences (Beijing) Beijing 100083 China

To measure elastic wave velocities in rocks at high temperature and high pressure is an important way to acquire the mechanics and thermodynamics data of rocks in the earth? interior and also a substantial approach to studying the structure and composition of materials there. In recent years, a rapid progress has been made in methodology pertaining to the measurements of elastic wave velocities in rocks at high temperature and high pressure with solids as the pressuretransfer media. However, no strict comparisons have been made of the elastic wave velocity data of rocks measured at high temperature and high pressure by various laboratories. In order to compare the experimental results from various laboratories, we have conducted a comparative experimental study on three measuring methods and made a strict comparison with the results obtained by using the transmission method with fluid as the pressure-transfer medium. Our experimental results have shown that the measurements obtained by the three methods are comparable in the pressure ranges of their application. The cubic sample pulse transmission method used by Kern is applicable to measuring elastic wave velocities in crustal rocks at lower temperature and lower pressure. The prism sample pulse reflection-transmission method has some advantagesin pressure range, heating temperature and measuring precision. Although the measurements obtained under relatively low pressure conditions by the prism sample pulse transmission method are relatively low in precision, the samples are large in length and their assemblage is simple. So this method is suitable to the experiments that require large quantities of samples and higher pressures. Therefore, in practical application the latter two methods are usually recommended because their measurements can be mutually corrected and supplemented.

关键词： elastic wave velocity, rock, high temperature and high pressure, measuring method.

Two advances on the photoelectric parallel measuring of spectrum

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Chinese Science Bulletin 1997年第23期42卷 1965-1970页

作者： Lin, LZ Pu, XY Zhang, J Wen, XM Liu, QJ Yunnan Univ Dept Phys Kunming 650091 Peoples R China

THE tendency of the technique of spectral measurement is now towards sensitivity, precision,quickness, time and spatial resolving spectrum. For the spectrophotometers, which acquirespectral data with the serious method, the measurement of spectral intensity for differentwavelengths is not simultaneous. It is difficult to quickly get a spectrum, because time must bespent on tuning the dispersive device, and it is also impossible to process time and spatial Te-solving spectrum. The problems mentioned above are the fatal disadvantages for further devel-oping the spectrophotometer equipped with monochromator. The best way to solve these prob-

关键词： photoelectric parallel measuring of spectrum system’ s resolving power simultaneous spectral width multilayer gratings polychromator.

Spatial Downscaling of the Tropical Rainfall measuring Mission Precipitation Using Geographically Weighted Regression Kriging over the Lancang River Basin, China

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Chinese Geographical Science 2019年第3期29卷 446-462页

作者： LI Yungang ZHANG Yueyuan HE Daming LUO Xian JI Xuan Institute of International Rivers and Eco-security Yunnan University Yunnan Key Laboratory of International Rivers and Transboundary Eco-security Yunnan University

Satellite-based precipitation products have been widely used to estimate precipitation, especially over regions with sparse rain gauge networks. However, the low spatial resolution of these products has limited their application in localized regions and *** study investigated a spatial downscaling approach, Geographically Weighted Regression Kriging(GWRK), to downscale the Tropical Rainfall measuring Mission(TRMM) 3 B43 Version 7 over the Lancang River Basin(LRB) for 2001–2015. Downscaling was performed based on the relationships between the TRMM precipitation and the Normalized Difference Vegetation Index(NDVI), the Land Surface Temperature(LST), and the Digital Elevation Model(DEM). Geographical ratio analysis(GRA) was used to calibrate the annual downscaled precipitation data, and the monthly fractions derived from the original TRMM data were used to disaggregate annual downscaled and calibrated precipitation to monthly precipitation at 1 km resolution. The final downscaled precipitation datasets were validated against station-based observed precipitation in 2001–2015. Results showed that: 1) The TRMM 3 B43 precipitation was highly accurate with slight overestimation at the basin scale(i.e., CC(correlation coefficient) = 0.91, Bias = 13.3%). Spatially, the accuracies of the upstream and downstream regions were higher than that of the midstream region. 2) The annual downscaled TRMM precipitation data at 1 km spatial resolution obtained by GWRK effectively captured the high spatial variability of precipitation over the LRB. 3) The annual downscaled TRMM precipitation with GRA calibration gave better accuracy compared with the original TRMM dataset. 4) The final downscaled and calibrated precipitation had significantly improved spatial resolution, and agreed well with data from the validated rain gauge stations, i.e., CC = 0.75, RMSE(root mean square error) = 182 mm, MAE(mean absolute error) = 142 mm, and Bias = 0.78%for annual precipitation and CC = 0.9

关键词： precipitation Tropical Rainfall measuring Mission(TRMM) 3B43 Geographically Weighted Regression Kriging(GWRK) spatial downscaling the Lancang River Basin,China

Analysis on thermal measuring of green roof

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Journal of Central South University 2009年第S1期16卷 150-153页

作者：唐鸣放蒋琳 Key Laboratory of New Technology for Construction of Cities in Mountain Area Ministry of EducationChongqing University

Comparison of thermal performance between a green roof room and a bare roof room was presented during the cooling period in Shanghai. The results show that the electricity can be saved about 0.08 kW·h/(d·m2),and the heat flux can be reduced by about 70%; the inner surface temperature variation is about 1.0 ℃ comparing with the indoor temperature when using the green roof,and the extra equivalent heat resistance is 1.0 m2·K/W.

关键词： green roof energy saving thermal measuring

NEW METHOD FOR measuring SECONDARY ELECTRON EMISSION OF THERMIONIC CATHODE AND ITS APPLICATION

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Journal of Electronics(China) 1990年第3期7卷 273-279页

作者：陈德森孙学民 Southeast-University Nanjing

By using correlation-detection technique and improving structure of the test tube,the background noise of thermionic-electrons and space charge effect are *** sec-ondary emission coefficient δ of thermionic cathode at high temperature has been ***δ of impregnated scandate cathodes increases exponentially with increasing temperature at lowenergy and current of the bombardment electrons;at high energy or current of the bombardmentelectrons the temperature has little effect on δ.The research shows that an enhanced thermionicemission occurred when the cathode works at high temperature and under electron *** phenomena are discussed in terms of “internal field model”.

关键词： Thermionic cathode Method for measuring secondary electron emission Scandate cathode Internal field model

Multi-matrix opto-electronic system for measuring deformation of the millimeter range radiotelescope elements

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Optoelectronics Letters 2019年第2期15卷 144-146页

作者： LI Ren-pu Konyakhin Igor Tong Minh Hoa ZHOU Min Chongqing Engineering Research Center of Intelligent Sensing Technology and Microsystem Chongqing University of Post and Telecommunications Faculty of Applied Optic ITMO University

A novel optical instrument is proposed and studied to measure the deformation of each connection point for a mirror, which includes 24 multi-matrix base units and can be used in millimeter-scale signal reflection *** investigations reveal that the error of measurement is σ=8.7×10^(-3) mm at a distance of 5 500 mm, which allows to measure the linear deformation of a radiotelescope with the mirror diameter of 70 m.

关键词： measuring radiotelescope instrument

An Open CNC Based Integrated measuring,Modeling and Manufacturing System Architecture

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武汉理工大学学报 2006年第S1期28卷 238-242页

作者： WANG Huabing 1,2 ,LIU Weijun1 (1. Advanced Manufacturing Laboratory,Shenyang Institute of Automation,The Chinese Academy of Science,Shenyang 110016, China 2. Graduate School of the Chinese Academy of Sciences,Beijing 100039,China) Advanced Manufacturing Laboratory Shenyang Institute of AutomationThe Chinese Academy of ScienceShenyang 110016China Graduate School of the Chinese Academy of Sciences Beijing 100039China Advanced Manufacturing Laboratory Shenyang Institute of AutomationThe Chinese Academy of ScienceShenyang 110016China

A new architecture based on open-architecture CNC of an integrated measuring,modeling and manufacturing system is presented. A 3-axis vertical milling structure is used to achieve the manufacturing function. And a computer vision camera is to be set up on the holder of the milling machine to capture the images of the work-piece and a image data acquisition card is used to translate the image data to the control computer,which acts as the measuring subsystem. Through processing the image data the model of the work-piece is established which plays the role of modeling subsystem. A motion control card is inserted into an industry computer to construct an open CNC system of the type of NC embedded PC which is more sophisticated than other new technologies on open CNC. The embedded motion card burdens the real-time tasks of the system and the IPC does the other management and planning tasks. The IPC together with the motion control card command the three axes of the system to accomplish the manufacturing and measuring functions and further the modeling function.

关键词： CNC measuring modeling manufacturing open-architecture