期刊文献+
共找到8,063篇文章
< 1 2 250 >
每页显示 20 50 100
Multipoint Infrared Telemetry System for Measuring the Piston Temperature in Internal Combustion Engines 被引量:5
1
作者 刘金祥 魏春源 +1 位作者 张卫正 郭良平 《Journal of Beijing Institute of Technology》 EI CAS 2002年第4期346-349,共4页
A high precision, high antijamming multipoint infrared telemetry system was developed to measure the piston temperature in internal combustion engine. The temperature at the measuring point is converted into correspon... A high precision, high antijamming multipoint infrared telemetry system was developed to measure the piston temperature in internal combustion engine. The temperature at the measuring point is converted into corresponding voltage signal by the thermo-couple first. Then after the V/F stage, the voltage signal is converted into the frequency signal to drive the infrared light-emitting diode to transmit infrared pulses. At the receiver end, a photosensitive audion receives the infrared pulses. After conversion, the voltage recorded by the receiver stands for the magnitude of temperature at the measuring point. Test results of the system indicate that the system is practical and the system can perform multipoint looping temperature measurements for the piston. 展开更多
关键词 PISTON temperature measurement infrared telemetry
下载PDF
Study on New Generation Spaceborne Rain and Cloud Measuring Radar System Techniques 被引量:1
2
作者 商建 杨汝良 《Meteorological and Environmental Research》 CAS 2010年第9期4-8,11,共6页
Dual-frequency and multi-polarization spaceborne rain and cloud measuring radar is the inevitable trend of remote sensing techniques.Techniques of new generation dual-frequency and multi-polarization spaceborne rain a... Dual-frequency and multi-polarization spaceborne rain and cloud measuring radar is the inevitable trend of remote sensing techniques.Techniques of new generation dual-frequency and multi-polarization spaceborne rain and cloud measuring radar are studied systematically.Radar block diagram and main parameters are presented.Antenna subsystem scheme is analyzed and antenna parameters are proposed.Central electronic device subsystem scheme is given and data rate of spaceborne radar is calculated.This paper is a meaningful try for carrying out spaceborne rain and cloud measuring radar design,acting as a reference to Chinese spaceborne rain and cloud measuring radar design and production in future. 展开更多
关键词 Spaceborne rain and cloud measuring radar Dual-frequency and multi-polarization Subsystem scheme China
下载PDF
NEW MODEL OF THEODOLITE INDUSTRIAL MEASURING SYSTEM
3
作者 熊春宝 叶声华 +1 位作者 王仲 匡绍君 《Transactions of Tianjin University》 EI CAS 1999年第2期78-82,共5页
Comparing with the coordinates measuring machine (CMM),the theodolite industrial measuring system (TIMS) can be easily moved and it can measure large sized industrial targets contactlessly.But up to now the precision... Comparing with the coordinates measuring machine (CMM),the theodolite industrial measuring system (TIMS) can be easily moved and it can measure large sized industrial targets contactlessly.But up to now the precision of the TIMS has been considered so low that the TIMS isnt applied to some precise measurements.The error in self locating TIMS is a main factor which affects the precision of the TIMS.A new model of the TIMS is given out in this paper,and it can eliminate the error in self locating the TIMS.The new model is not only investigated and analyzed theoretically but also verified by the real measured data. 展开更多
关键词 model theodolite industrial measuring system (TIMS) self location of system
下载PDF
Single Camera 3-D Coordinate Measuring System Based on Optical Probe Imaging 被引量:4
4
作者 MAShu-ying YUZhi-jing 《Semiconductor Photonics and Technology》 CAS 2001年第4期235-240,共6页
A new vision coordinate measuring system--single camera 3 D coordinate measuring system based on optical probe imaging is presented. A new idea in vision coordinate measurement is proposed. A linear model is deduced w... A new vision coordinate measuring system--single camera 3 D coordinate measuring system based on optical probe imaging is presented. A new idea in vision coordinate measurement is proposed. A linear model is deduced which can distinguish six freedom degrees of optical probe to realize coordinate measurement of the object surface. The effects of some factors on the resolution of the system are analyzed. The simulating experiments have shown that the system model is available. 展开更多
关键词 Three dimensional measurement Vision coordinate measurement Optical probe Linear model
下载PDF
Deep-Hole Inner Diameter Measuring System Based on Non-contact Capacitance Sensor 被引量:3
5
作者 于永新 张恒 +1 位作者 王宗超 常以哲 《Transactions of Tianjin University》 EI CAS 2010年第6期447-451,共5页
A precise aperture measuring system of small deep holes with capacitance sensors is presented. Based on the working principle of non-contact capacitance sensors, influence of the edge effect of gauge head is studied, ... A precise aperture measuring system of small deep holes with capacitance sensors is presented. Based on the working principle of non-contact capacitance sensors, influence of the edge effect of gauge head is studied, and one capacitance sensor for measuring the aperture of the small blind holes or through holes is introduced. The system is composed of one positioning device, one aperture measuring capacitance sensor, one measuring circuit, and software. This system employs visual CCD and two-dimensional mic... 展开更多
关键词 deep-hole measurement NON-CONTACT CCD stepping motor precise positioning
下载PDF
DISTANCE MEASURING MODELING AND ERROR ANALYSIS OF DUALCCD VISION SYSTEM SIMULATING HUMAN EYES AND NECK 被引量:3
6
作者 Wang XuanyinXiao BaopingPan FengState Key Laboratory of Fluid PowerTransmission and Control,Zhejiang University,Hangzhou 310027, China 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2003年第4期396-399,共4页
A dual-CCD simulating human eyes and neck (DSHEN) vision system is putforward. Its structure and principle are introduced. The DSREN vision system can perform somemovements simulating human eyes and neck by means of f... A dual-CCD simulating human eyes and neck (DSHEN) vision system is putforward. Its structure and principle are introduced. The DSREN vision system can perform somemovements simulating human eyes and neck by means of four rotating joints, and realize preciseobject recognizing and distance measuring in all orientations. The mathematic model of the DSHENvision system is built, and its movement equation is solved. The coordinate error and measureprecision affected by the movement parameters are analyzed by means of intersection measuringmethod. So a theoretic foundation for further research on automatic object recognizing and precisetarget tracking is provided. 展开更多
关键词 Dual-CCD Simulating human eyes and neck (DSHEN) Intersection measure ERRORANALYSIS Homogeneous coordinate transformation
下载PDF
Clinical study using novel endoscopic system for measuring size of gastrointestinal lesion 被引量:2
7
作者 Kiyoshi Oka Takeshi Seki +3 位作者 Tomohiro Akatsu Takao Wakabayashi Kazuo Inui Junji Yoshino 《World Journal of Gastroenterology》 SCIE CAS 2014年第14期4050-4058,共9页
AIM: To verify the performance of a lesion size measurement system through a clinical study.
关键词 Lesion size Non-contact measurement ENDOSCOPE Grid scale Low level laser
下载PDF
Development of Measuring System of Plant Electrical Potential and Its Application 被引量:1
8
作者 Yu Haiye Li Guochen Ma Chenglin 《仪器仪表学报》 EI CAS CSCD 北大核心 2005年第z1期369-373,共5页
Based on the characters of plant potentials, it introduced the construction and technology in developing the measuring system of plant electrical potentials, the input impedance of the amplifier must be enough high(= ... Based on the characters of plant potentials, it introduced the construction and technology in developing the measuring system of plant electrical potentials, the input impedance of the amplifier must be enough high(= 1010~ 1012Ω) in order to measuring the plant weak signals and ensuring high common mode rejection ratio (CMRR). And wavelet transform was applied in denoising based on cross-validation (CV)threshold value. the experiment showed that this system could effectively detect the change of plant potentials,four-week old cucumber was stimulated by heat wounding, the variation potential (VP) and action potential(AP) would be evoked, the AP's varying amplitude can reach 40mV; the AP changed very fast, its duration time is about 0.01~0.02s and its amplitude often change from 15μV~5mV. 展开更多
关键词 PLANT POTENTIALS VARIATION POTENTIAL (VP) Action POTENTIAL (AP) measuring system
下载PDF
General Consideration of Measuring System for Operational Test of Thyristor Valves of Ultra High Voltage DC Power Transmission 被引量:1
9
作者 ZHOU Hui-gao XU Fan +2 位作者 ZHANG Chang-chun HU Zhi-long LIU Pu 《高压电器》 CAS CSCD 北大核心 2011年第9期1-5,共5页
Thyristor valve is one of the key equipments for ultra high voltage direct current(UHVDC) power transmission projects.Before being installed on site,they need to be tested in a laboratory in order to verify their oper... Thyristor valve is one of the key equipments for ultra high voltage direct current(UHVDC) power transmission projects.Before being installed on site,they need to be tested in a laboratory in order to verify their operational performance to satisfy the technical specification of project related.Test facilities for operational tests of thyristor valves are supposed to enable to undertake more severe electrical stresses than those being applied in the thyristor valves under test(test objects).On the other hand,the stresses applied into the test objects are neither higher nor lower than specified by the specification,because inappropriate stresses applied would result in incorrect evaluation of performance on the test objects,more seriously,would cuase the damage of test objects with expensive cost losing.Generally,the process of operational tests is complicated and performed in a complex synthetic test circuit(hereafter as STC),where there are a lot of sensors used for measuring,monitoring and protection on line to ensure that the test circuit functions in good condition.Therefore,the measuring systems embedded play a core role in STC,acting like "eyes".Based on the first project of building up a STC in China,experience of planning measuring systems is summarized so as to be referenced by related engineers. 展开更多
关键词 UHVDC thyristor valves operational test synthetic test circuit measuring system planning
下载PDF
A time-dependent measuring system for welding deformation 被引量:2
10
作者 蔡志鹏 赵海燕 +2 位作者 鹿安理 史清宇 施光凯 《China Welding》 EI CAS 2002年第1期25-28,共4页
In this paper the establishment and application of a time dependent measuring system for welding deformation are presented which is established with high quality sensors shielded from strong welding interference. By ... In this paper the establishment and application of a time dependent measuring system for welding deformation are presented which is established with high quality sensors shielded from strong welding interference. By using this system, vertical and horizontal displacements of the high temperature area are surveyed at the same time. And this system is also used for monitoring and controlling the deformation of real welded structures. 展开更多
关键词 time dependent measuring system welding deformation
下载PDF
A Study on Comprehensive Modeling for Errors in on-line Measuring System of Machining Center 被引量:1
11
作者 Liu Libing Zhang Qing(Tianjin University, Tianjin (300072) P. R. of ChinaZap Hongmei Yun Jintian)(Hebei University Of Technology, Tianjin (300130) P. R. of China) 《河北工业大学学报》 CAS 1997年第A01期14-22,共9页
Based on the theory of multi-body system (MBS), bine’s and huston’s methods are applied to an on-line measuring system of machining center in this paper. Through the study on modeling technique, the comprehensive mo... Based on the theory of multi-body system (MBS), bine’s and huston’s methods are applied to an on-line measuring system of machining center in this paper. Through the study on modeling technique, the comprehensive model for errors calculation in an on-line measuring System of machining center have been built for the first time. Using this model, the errors can be compensated by soft.ware and the measuring accuracy can be enhanced without any more inveSt. This model can be used in all kinds of machining center. 展开更多
关键词 MACHINING CENTER ON-LINE measuring Multi-Body system (MBS) Model
下载PDF
Development of an in-situ measuring system for blisk manufacturing 被引量:1
12
作者 ZHANG Hai-tao LIU Shu-gui +1 位作者 LI Xing-hua SU Zhi-kun 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2018年第2期115-120,共6页
In order to solve the in-situ measurement problem of workpiece with complex structures,a cantilever coordinate measuring machine(CCMM)is proposed to adapt to the finite space constraints of the 5-axis computer numeric... In order to solve the in-situ measurement problem of workpiece with complex structures,a cantilever coordinate measuring machine(CCMM)is proposed to adapt to the finite space constraints of the 5-axis computer numerical control(CNC)processing site.Structure design of dense ball bearing shafting is analyzed and optimized.Factors affecting measurement accuracy of CCMM are analyzed,and measurement accuracy is validated by experiments.Results show that the structure of CCMM is able to satisfy requirements of technical specification,and the in-situ measurement of blisk manufacturing is realized.The CCMM developed is of important significance for machining quantity improvement of blisk and development of large aircraft production. 展开更多
关键词 BLISK in-situ measurement cantilever coordinate measuring machine(CCMM)
下载PDF
RESEARCH ON THE ON-LINE MEASURING SYSTEM FOR THE MIDDLE-CONVEX AND VARYING ELLIPSE PISTON SKIRT 被引量:1
13
作者 Wang Xiankui,Jiang Simin,Qian Lei,Shi Zhongdong,Wu Dan (Department of the Precision Instrument and Mechanics,Qinghua University) 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2001年第4期305-309,共5页
The middle convex and varying ellipse piston is th e key component of an internal combustion engine In general,the piston is mac hined by non circular section CNC lathe,but the measuring of piston profile is man... The middle convex and varying ellipse piston is th e key component of an internal combustion engine In general,the piston is mac hined by non circular section CNC lathe,but the measuring of piston profile is manipulated by off line Because the off line measuring reference is differen t from the machining reference,the measurement result is diverse from the act ual dimension A new method to measure the middle convex and varying ellipse p iston profile, which is known as on line measuring, is presented By using thi s kind of method,the high measurement accuracy can be gained,as well as meeting the production requirement. 展开更多
关键词 Middle-convex and varying ellipse piston On -line measure Non circular section
下载PDF
Orthogonality of inductosyn angle-measuring system error and error-separating technology 被引量:1
14
作者 任顺清 曾庆双 王常虹 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2003年第4期376-379,共4页
Round inductosyn is widely used in inertial navigation test equipment, and its accuracy has significant effect on the general accuracy of the equipment. Four main errors of round inductosyn,i.e. the first-order long-p... Round inductosyn is widely used in inertial navigation test equipment, and its accuracy has significant effect on the general accuracy of the equipment. Four main errors of round inductosyn,i.e. the first-order long-period (360°) harmonic error, the second-order long-period harmonic error, the first-order short-period harmonic error and the second-order short-period harmonic error, are described, and the orthogonality of these four kinds of errors is studied. An error separating technology is proposed to separate these four kinds of errors, and in the process of separating the short-period harmonic errors, the arrangement in the order of decimal part of the angle pitch number can be omitted. The effectiveness of the technology proposed is proved through measuring and adjusting the angular errors. 展开更多
关键词 INDUCTOSYN angle measurement error separation ORTHOGONALITY
下载PDF
GDOP’s Influence on Observable Degree of Multi-Antenna GPS/SINS Integrated Attitude Measuring System 被引量:1
15
作者 Hao He Yuhang Zheng +2 位作者 Dongfang Yang Jinsheng Zhang Shicheng Wang 《World Journal of Engineering and Technology》 2015年第3期354-359,共6页
GDOP’s influence on observable degree is studied by analyzing a multi-antenna GPS/SINS attitude measuring system. Firstly, the mathematical model of the attitude measuring system, whose observations are single-differ... GDOP’s influence on observable degree is studied by analyzing a multi-antenna GPS/SINS attitude measuring system. Firstly, the mathematical model of the attitude measuring system, whose observations are single-differences, is provided;Secondly, it is proved that the model can be studied by PWCS theory, and GDOP’s influence on observable degree is explained intuitively. Then, the variance of observable degree is studied by simulation while GDOP is different, and the result is analysed. Simulation results show that, the observable degree becomes worse with the increasing GDOP value. Therefore, while designing such kind of Kalman filter, the influence to observable degree which made by GDOP should be considered adequately. 展开更多
关键词 ATTITUDE measuring OBSERVABLE DEGREE SVD GDOP
下载PDF
Development of a Three-Dimensional Measuring System for Neonates' Head and Facial Morphology 被引量:1
16
作者 邓咏梅 易洁伦 +2 位作者 郭绮莲 黄小珍 吴新培 《Journal of Donghua University(English Edition)》 EI CAS 2007年第3期309-312,共4页
A web camera based multi-camera convergent close-range photogrammetric system is developed to obtain the neonates' head and facial morphology. The data will then be used to develop a secure and good-fitting eye-patch... A web camera based multi-camera convergent close-range photogrammetric system is developed to obtain the neonates' head and facial morphology. The data will then be used to develop a secure and good-fitting eye-patch protector for neonates, particularly whoa they are exposed to bright lights such as phototherapy light. Measurements obtained by the system are evaluated and validated against data obtained from optical scanning. Results show that the photogrammetric system meets the requirements of measuring accuracy and safety for neonate in the neonatal units. 展开更多
关键词 close-range photogrammetry (CRP) three-dimensional measurement NEONATES head and facialmorphology
下载PDF
Research on Solar Simulation System for Test of Solar Radiation Measuring Instrument 被引量:5
17
作者 ZhengRu Zhang Guoyu +3 位作者 Lyu Wenhua Yan Jiajun Su Shi Zhang Jian 《Instrumentation》 2017年第1期3-11,共9页
Since traditional solar simulators are mainly applied to spacecraft and photovoltaic industry,they are not suitable for solar radiation measuring instrument test. Therefore,a deep research is carried out on solar simu... Since traditional solar simulators are mainly applied to spacecraft and photovoltaic industry,they are not suitable for solar radiation measuring instrument test. Therefore,a deep research is carried out on solar simulators to test of solar radiation measuring instrument,so that obtain the requirements of performance test of solar radiation measuring instrument. With a combination of the requirements for national regulations of metrological verification and performance test of pyranometer and pyrheliometer,it lays emphasis on the research of design methods for improving radiation uniformity and stability of solar simulators; it also focuses on design methods of multidimensional detection workbench,which achieves different detection of solar radiation. After practical test,solar irradiation is within Φ60 mm; irradiation non-uniformity is better than ±0.8%; instability is better than ±0.72%;rotating angle precision is better than 0.09°. Then,solar simulator is used to carry out pyranometer sensitivity test,pyranometer directional response test,pyranometer tilt response test and non-linearity test for radiation instruments. Test results showthat the solar simulator meets the testing requirements of solar radiation measuring instruments. 展开更多
关键词 Solar Simulation system Irradiation Non-uniformity Irradiation Stability Solar Radiation measuring Instrument TEST
下载PDF
Research on key techniques of expendable conductivity temperature depth measuring system 被引量:5
18
作者 CHEN Guangyuan DU Libin +3 位作者 HE Haijing LEI Zhuo ZHANG Qisheng WU Chengxuan 《Instrumentation》 2015年第2期18-27,共10页
This paper analysis the developing of expendable conductivity temperature depth measuring system(XCTD)and introduce its principle of measuring about temperature,salinity and depth of ocean.Some key techniques are put ... This paper analysis the developing of expendable conductivity temperature depth measuring system(XCTD)and introduce its principle of measuring about temperature,salinity and depth of ocean.Some key techniques are put forward.According to the real needs of XCTD,conductivity sensor with high sensitivity is designed by principle of electromagnetic induce,the ocean conductivity from induced electromotive force has been calculated.Adding temperature correction circuit would help to reduce error of conductivity measurement because of sharply changing temperature.Advanced temperature measuring circuit of high precision and the constant current source is used to weaken effect of self-heating of resistance and fluctuation of the source.On respect of remote data transmission,LVDS is a good choice for the purpose of guarantee the quality of data transmitted and the transmission distance is reaching to thousand meters in the seawater.Modular programming method is also brought into this research aimed at improve the stability,reliability and maintainability of the whole measuring system.In February,2015,the trials in South China Sea demonstrate that the developed XCTD realize effective measurement at a speed of 6 knots and detection depth at 800 m.The consistency coefficient of the acquired data is greater than 0.99 and the success rate of probe launching is above 90%. 展开更多
关键词 expendable device XCTD conductivity sensor high precision temperature measuring circuit remote data transmission
下载PDF
A Home Appliance Recognition System Using the Approach of Measuring Power Consumption and Power Factor on the Electrical Panel, Based on Energy Meter ICs 被引量:1
19
作者 Jefferson Z. Moro Luís F. C. Duarte +1 位作者 Elnatan C. Ferreira José A. Siqueira Dias 《Circuits and Systems》 2013年第3期245-251,共7页
Currently a large effort is being done with the intention to educate people about how much energy each electrical appliance uses in their houses, since this knowledge is the fundamental basis of energy efficiency prog... Currently a large effort is being done with the intention to educate people about how much energy each electrical appliance uses in their houses, since this knowledge is the fundamental basis of energy efficiency programs that can be managed by the household owners. This paper presents a simple yet functional non-intrusive method for electric power measurement that can be applied in energy efficiency programs, in order to provide a better knowledge of the energy consumption of the appliances in a home. 展开更多
关键词 ENERGY CONSUMPTION ENERGY Efficiency ENERGY METERING Power Measurement
下载PDF
Drilling-based measuring method for the c-φ parameter of rock and its field application 被引量:3
20
作者 Bei Jiang Fenglin Ma +5 位作者 Qi Wang Hongke Gao Dahu Zhai Yusong Deng Chuanjie Xu Liangdi Yao 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2024年第1期65-76,共12页
The technology of drilling tests makes it possible to obtain the strength parameter of rock accurately in situ. In this paper, a new rock cutting analysis model that considers the influence of the rock crushing zone(R... The technology of drilling tests makes it possible to obtain the strength parameter of rock accurately in situ. In this paper, a new rock cutting analysis model that considers the influence of the rock crushing zone(RCZ) is built. The formula for an ultimate cutting force is established based on the limit equilibrium principle. The relationship between digital drilling parameters(DDP) and the c-φ parameter(DDP-cφ formula, where c refers to the cohesion and φ refers to the internal friction angle) is derived, and the response of drilling parameters and cutting ratio to the strength parameters is analyzed. The drillingbased measuring method for the c-φ parameter of rock is constructed. The laboratory verification test is then completed, and the difference in results between the drilling test and the compression test is less than 6%. On this basis, in-situ rock drilling tests in a traffic tunnel and a coal mine roadway are carried out, and the strength parameters of the surrounding rock are effectively tested. The average difference ratio of the results is less than 11%, which verifies the effectiveness of the proposed method for obtaining the strength parameters based on digital drilling. This study provides methodological support for field testing of rock strength parameters. 展开更多
关键词 Digital drilling Rock crushing zone c-u parameter Measurement method Field application
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部