期刊文献+
共找到24篇文章
< 1 2 >
每页显示 20 50 100
New System to Measure the Yaw and PitchAngles of Rocket in Launch Phase
1
作者 王志军 王瑞臣 +1 位作者 王辉 蔡汉文 《Journal of Beijing Institute of Technology》 EI CAS 1998年第1期73-77,共5页
Aim To describe a news system for measuring the and pitch angles of rocket during the launch phase Methods Optical system was to reflect the spot that represents the angular movement of rocket to the position sensitiv... Aim To describe a news system for measuring the and pitch angles of rocket during the launch phase Methods Optical system was to reflect the spot that represents the angular movement of rocket to the position sensitive detector that can convert analogue signal into digital one.Results Compared with conventional optical lever test system which had been applied to measure rocket attitude angle,the new system used the position sensitive detector to replace the screen and high-speed photographic instrumentation as grapher,which can avert photointerpretive data reduction and apply to field experiment more easily and pre- cisely .Conclusion Experimental results show that the test system can be used in measuring the yaw and pitch angles of rocket effectively. 展开更多
关键词 ROCKETS attitude angle position sensitive detector test system
下载PDF
Detection technique of moving target based on passive millimeter wave
2
作者 李世中 牟春阳 张勇 《Journal of Measurement Science and Instrumentation》 CAS 2014年第4期29-33,共5页
To solve the problem of insufficient ability when detecting the high-speed moving target with passive millimeter wave technology, a direct-detection passive millimeter wave detecting system using the monolithic microw... To solve the problem of insufficient ability when detecting the high-speed moving target with passive millimeter wave technology, a direct-detection passive millimeter wave detecting system using the monolithic microwave integrated cir- cuit (MMIC) millimeter wave radiometer is built, and the measured data are obtained by experiment under different condi- tions. Based on feature analysis of testing signals, it points out that the peak of the first pulse and interval of two peak pulses are valid features which can reflect the motion characteristic of target. A method to calculate the moving speed of target is put forward. The calculating results indicate that the proposed method has enough accuracy and is feasible to determine the parameters of the moving target using for passive millimeter wave system. 展开更多
关键词 passive millimeter wave technology millimeter wave radiometer detection of moving target feature analysis moving speed of target
下载PDF
A new diamond bit for extra-hard, compact and nonabrasive rock formation 被引量:4
3
作者 王佳亮 张绍和 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第4期1456-1462,共7页
A new impregnated diamond bit was designed to solve the slipping problem when impregnated diamond bit was used for extra-hard, compact, and nonabrasive rock formation. Adding Si C grits into matrix, Si C grits can eas... A new impregnated diamond bit was designed to solve the slipping problem when impregnated diamond bit was used for extra-hard, compact, and nonabrasive rock formation. Adding Si C grits into matrix, Si C grits can easily be exfoliated from the surface of the matrix due to weak holding-force with matrix, which made the surface non-smooth. Three Ф36/24 mm laboratorial bits were manufactured to conduct a laboratory drilling test on zirconiacorundum refractory brick. The laboratory drilling test indicates that the abrasive resistance of the bit work layer is proportional to the Si C concentation. The higher the concentration, the weaker the abrasive resistance of matrix. The new impregnated diamond bit was applied to a mining area drilling construction in Jiangxi province, China. Field drilling application indicates that the ROP(rate of penetration) of the new bit is approximately two to three times that of the common bits. Compared with the common bits, the surface of the new bit has typical abrasive wear characteristics,and the metabolic rate of the diamond can be well matched to the wear rate of the matrix. 展开更多
关键词 SiC grits impregnated diamond bit non-smooth surface diamond rock fragmentation mechanism
下载PDF
Magnetic field properties caused by stress concentration 被引量:14
4
作者 黄松岭 李路明 +1 位作者 施克仁 王晓凤 《Journal of Central South University of Technology》 2004年第1期23-26,共4页
Measurements of the effects of tensile stress on magnetic field properties, infrared thermography and (acoustic) emission of a cuboid sample with an elliptical hole in its center were presented. The tensile stress was... Measurements of the effects of tensile stress on magnetic field properties, infrared thermography and (acoustic) emission of a cuboid sample with an elliptical hole in its center were presented. The tensile stress was applied perpendicularly to the sample by electro-tension machine according to a step-loading curve. The changes of the sample temperature was recorded by an infrared thermography system and the noise of domain reversal was inspected by two acoustic probes, which were placed on each end of the sample near the collets of the electro-tension machine, when the sample was in loading process. The magnetic fields on the surface of the sample were inspected with 8 mm lift-off when the loads were held. Valuable information about the changes of domains was obtained from analysis of acoustic emission signals in loading process. Infrared images of the sample provided complementary information about the state of the sample. The results show that stress concentration in ferromagnetic material affects the direction and structure of domain and generates net magnetic moment on its surface. The distribution and magnitude of the net magnetic moment are correlative with those of stress. 展开更多
关键词 magnetic field testing stress concentration THERMOGRAPHY acoustic emission DOMAIN
下载PDF
DESIGN OF MULTI-SERVICE SDH NETWORKS: FORMULATION AND HEURISTICS
5
作者 Xi Kang Ge Ning Feng Chongxi (Department of Electronic Engineering, Tsinghua University, Beijing 100084) 《Journal of Electronics(China)》 2003年第3期215-219,共5页
Multi-service SDH networks support both packet- and circuit-switched traffic. Optimal design of such a network means to guarantee the circuit connections and configure a logical packet-switched topology with lowest co... Multi-service SDH networks support both packet- and circuit-switched traffic. Optimal design of such a network means to guarantee the circuit connections and configure a logical packet-switched topology with lowest congestion. This letter first formulates the problem as a mixed integer linear programming, which achieves optimal solution but has high computation. Then a heuristic algorithm is proposed to yield near-optimal solution efficiently. Performance of the algorithm is verified by an example. 展开更多
关键词 Multi-service networks Logical topology design SDH
下载PDF
Development of a Research Probe for Geothermal Boreholes
6
作者 Joerg Isele Benedict Holbein 《Journal of Earth Science and Engineering》 2013年第12期815-828,共14页
This paper introduces the idea of a framework for the implementation of novel downhole probes. A couple of examples (e.g. a tracer detector, a casing smear test probe or a casing repair probe) demonstrate that many ... This paper introduces the idea of a framework for the implementation of novel downhole probes. A couple of examples (e.g. a tracer detector, a casing smear test probe or a casing repair probe) demonstrate that many components can be reused. These are the "bricks" of the ZWERG toolkit which is developed to match the environment in boreholes. Two "bricks" are described in detail: The housing (1) has to resist the pressure and other mechanical stress in deep holes. The selection of the material and the calculation of the wall thickness are the main interests. In many applications, a thermal management (2) of the inside of the probe is absolutely necessary. A dewar vessel can uncouple the heat of the geothermal reservoir and the temperature in the probe. It is important to understand the physical heat flow mechanisms. A set of formulas allows a good estimation of the quantity of heat that warms up the probe. The toolkit contains some immaterial "bricks" like blueprints of proven designs or support for the logistic process of finding and purchasing compatible components. The intention to drill near magma chambers calls for a common eflbrt of the geothermal community to gather compatible components, assemblies and knowhow and makes it widely available. ZWERG could be a starting point. 展开更多
关键词 Borehole tools platform for engineering monitoring logging.
下载PDF
THE TEST OF APPLYING RADAR TREC WIND IN THREE-DIMENSIONAL VARIATIONAL ASSIMILATION 被引量:1
7
作者 万齐林 薛纪善 +1 位作者 陈子通 刘春霞 《Journal of Tropical Meteorology》 SCIE 2006年第1期59-66,共8页
The application of radar–derived TREC wind to 3DVAR assimilation system of GRAPeS-3DVardeveloped by Chinese Academy of Meteorological Sciences is introduced. The resulting fundamental feature isestimated when radar T... The application of radar–derived TREC wind to 3DVAR assimilation system of GRAPeS-3DVardeveloped by Chinese Academy of Meteorological Sciences is introduced. The resulting fundamental feature isestimated when radar TREC wind is assimilated into GRAPeS-3DVar system. It was found that radar TRECwind has better potential of the application in GRAPeS-3DVar system and can effectively improve the analyzedresults. Moreover a numerical experiment is performed in which tropical cyclones make landfall and transform;it also showed that the predicted effect can be improved when the radar TREC wind is added into GRAPeS-3DVar system. 展开更多
关键词 radar-derived TREC wind 3DVAR Numerical experiment
下载PDF
Optical Test of Local Hidden—Variable Model
8
作者 WUXiao-Hua ZONGHong-Shi 《Communications in Theoretical Physics》 SCIE CAS CSCD 2001年第6期679-681,共3页
An inequality is deduced from local realism and a supplementary assumption. This inequality defines an experiment that can be actually performed with the present technology to test local hidden-variable models, and it... An inequality is deduced from local realism and a supplementary assumption. This inequality defines an experiment that can be actually performed with the present technology to test local hidden-variable models, and it is violated by quantum mechanics with a factor 1.92, while it can be simplified into a form where just two measurements are required. 展开更多
关键词 local hidden variable optical test
下载PDF
Enhancing diamond drilling performance by the addition of non-ionic polymer to the flushing media 被引量:2
9
作者 BHATNAGAR Anupam KHANDELWAL Manoj RAO Karanam Uma Maheshwar 《Mining Science and Technology》 EI CAS 2010年第3期400-405,共6页
Drilling is a most important and crucial operation in the excavation industries.With the objective of looking into the enhancement of diamond drilling performance detailed laboratory investigations were carried out on... Drilling is a most important and crucial operation in the excavation industries.With the objective of looking into the enhancement of diamond drilling performance detailed laboratory investigations were carried out on phosphate rock.The effect of Poly(Ethylene Oxide)(PEO) added to the drilling water was studied by varying machine parameters and PEO concentration.The responses were rate of penetration and torque at the bit rock interface.Slake durability tests were also performed to understand the slaking behavior of phosphate rock in PEO solutions. 展开更多
关键词 rotary diamond drilling flushing media polyethylene oxide rate of penetration TORQUE zero surface charge drilling
下载PDF
Measurement of thermal conductivity of materials using single-side TPS technique
10
作者 SUN Jian-qiang LI Yan-ning 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2019年第3期285-292,共8页
Based on the traditional measurement theory of transient plane source (TPS) technique, single-side TPS method is proposed for measuring the thermal conductivity of single specimen. The problem of transient heat conduc... Based on the traditional measurement theory of transient plane source (TPS) technique, single-side TPS method is proposed for measuring the thermal conductivity of single specimen. The problem of transient heat conduction in a semi-infinite boundary condition is studied and the theoretical formula of single-side TPS method is deduced. During the measurement, the influence of the probe heat capacity on the results is analyzed and the corresponding mathematical compensation model is established, and a series of experiments on different materials are conducted by hot disk probe at normal temperature and pressure. The results show that the relative error with the single-side TPS method is less than 5% and the relative standard deviation is no greater than 3%. This method has high accuracy and good reproducibility, which provides a feasible measuring method for single material that does not meet the requirements of the standard TPS theory. 展开更多
关键词 single-side transient plane source (TPS) method thermal conductivity single material probe heat capacity
下载PDF
Experimental analysis on bolt interference during advanced water detection with the mine transient electromagnetic method 被引量:2
11
作者 Xiong-Wu HU Ping-Song ZHANG +1 位作者 Jia-Ping YAN Pei-Gen LI 《Journal of Coal Science & Engineering(China)》 2013年第3期407-413,共7页
During advanced water detection using the transient electromagnetic method, the exploration effect for water-rich area is often poor due to the interference of bolts that are distributed in different positions in work... During advanced water detection using the transient electromagnetic method, the exploration effect for water-rich area is often poor due to the interference of bolts that are distributed in different positions in working face. Thus, the study on the interference characteristics of bolts in different states has important directive significance for improving the acquisition quality and data processing method in water detection. Based on the analysis of the distribution laws of magnetic field excited by small multi-turn coincident loop in full space of homogeneity, the test on the interference of bolts has been designed in the mine. Through drilling 18 holes around the overlapping coil in the working face, mass data are collected in order with the posi- tion change and the exposed bolt length. The results of comprehensive data analysis show that the transient electromagnetic field is strongly interfered as the distance between the bolt and the center of the coil is less than 3 m, and the interference varies greatly as the distance varies. On the other hand, the field induced by the bolts can be ignored as the distance exceeds 3 m. The findings can help to improve data acquisition and correction during advanced water detection when using the transient electromagnetic method. 展开更多
关键词 mine transient electromagnet advanced detection mine testing ground bolt interference attribute
下载PDF
The Role of Soil Investigation on Performance-based Design in Geotechnical Earthquake Engineering
12
作者 Antonio Cavallaro Salvatore Grasso Michele Maugeri 《Journal of Civil Engineering and Architecture》 2010年第2期33-40,共8页
The spatial variability of geotechnical earthquake engineering critical parameters obtained by laboratory and in situ tests in the same area is affected by different measurements. The paper provides a brief synthesis ... The spatial variability of geotechnical earthquake engineering critical parameters obtained by laboratory and in situ tests in the same area is affected by different measurements. The paper provides a brief synthesis of ground motion and site effects analysis procedures within a Performance-Based Design framework. In particular it focuses about the influence on the evaluation of site effects in some active regions by different shear waves velocity measurements (Down Hole D-H and Seismic Dilatometer Marchetti Test SDMT). Moreover the variation of shear modulus and damping ratio with strain level and depth from different laboratory dynamic or cyclic tests for soil characterisation (Resonant Column Test RCT) was evaluated. The available data enabled one to compare the shear waves velocity profile obtained by laboratory and in situ tests (Cone Penetration Tests CPT) with empirical correlations proposed in literature. 展开更多
关键词 Seismic Dilatometer Marchetti Test (SDMT) shear wave velocity St. Giuliano di Puglia (Italy) seismic response analysis.
下载PDF
Application of wireline formation tester in Tarim Oilfield
13
作者 WANG Zhaohui ZHANG Xiangdong 《Global Geology》 2013年第3期149-153,共5页
The application of wireline formation tester(WFT)gradually extends in oil-field with the constant improvement of instrument functions.Applications of WFT in oil and gas exploration in Tarim Oilfield,such as formation ... The application of wireline formation tester(WFT)gradually extends in oil-field with the constant improvement of instrument functions.Applications of WFT in oil and gas exploration in Tarim Oilfield,such as formation pressure measurement,are described,and testing efficiency between drill stem testing(DST)and WFT are compared,especially comprised of PVT sampling,hydrocarbon composition estimation,fluid characterization analysis and formation permeability analysis.The test results between WFT and traditional DST show that their functions can be complementary.The influence factors of WFT and the suitable applying conditions for WFT and DST are also discussed. 展开更多
关键词 WFT formation pressure PERMEABILITY DST PVT
下载PDF
Fast species identification of mycobacterium by rpoB gene chip technology
14
作者 LI Hong-min FAN Bo WANG Wei AN Hui-ru MIAO Qing 《Journal of Life Sciences》 2009年第5期43-46,共4页
Based on rpoB gene micro array as target gene, we are going to use gene chip technology to test 24 mycobacterium standard specimens, 8 non-mycobacterium specimens and 86 mycobacterium clinical isolated specimens. As a... Based on rpoB gene micro array as target gene, we are going to use gene chip technology to test 24 mycobacterium standard specimens, 8 non-mycobacterium specimens and 86 mycobacterium clinical isolated specimens. As a result, after mycobacterium and non-mycobacterium standard specimens were duplicated by PCR, mycobacterium standard specimens reproduced 360bp DNA fragments; on the other hand, non-mycobacterium specimens did not reproduce any fragments except for hemolytic streptococcus and corynebacterium pseudodiphtheriticum which had the same results as mycobacterium standard specimens. Sensitive test is able to detect lpg tuberculosis mycobacterium DNA. The probe test showed that, among 21 oligonucleotide probes, probe-M. fortuitum and M. marinum were cross-hybrid; the other probes were specific. We used the new method to identify 126 mycobacterium clinical isolated specimens. The test results of this new method matched with conventional method. In conclusion, compared to the traditional method, the use of rpob gene chip technology to identify mycobacterium species will be faster, more accurate and higher value in application. 展开更多
关键词 MYCOBACTERIUM rpoB gene chip technology oligonucleotide probes
下载PDF
Viscosity testing method of ultra-low temperature drilling fluids for polar glacier drilling 被引量:4
15
作者 HAN Lili XU Huiwen +2 位作者 CAO Pinlu YU Dahui P.G.Talalay 《Global Geology》 2012年第4期276-280,共5页
According to the working environment of the polar glacier core drilling, a separatory funnel capillary viscometer which can be used for testing the viscosity of liquids under ultra-low temperature conditions was de- s... According to the working environment of the polar glacier core drilling, a separatory funnel capillary viscometer which can be used for testing the viscosity of liquids under ultra-low temperature conditions was de- signed. This viscometer has a simple structure and it is easy to operate, which can meet the testing requirements of different temperature conditions. The viscosity of the dimethyl silicone oil KF-96L-2.0cs was measured under different temperatures using this designed viseometer, and it is found that the viscometer coefficient K changes linearly with temperature. This testing method has relatively high test accuracy and its relative error is less than 4%, which can be used to test the viscosity of the different liquids in ultra-low temperature conditions. 展开更多
关键词 polar drilling separatory funnel-capillary viscometer VISCOSITY dimethyl silicone oil viscometer coefficient
下载PDF
Integrated outburst detector sensor-model tests
16
作者 DZIURZYNSKI Waclaw WASILEWSKI Stanislaw 《Journal of Coal Science & Engineering(China)》 2011年第3期232-236,共5页
Outbursts of methane and rocks are, similarly to rock bursts, the biggest hazards in deep mines and are equally difficult to predict. The violent process of the outburst itself, along with the scale and range of hazar... Outbursts of methane and rocks are, similarly to rock bursts, the biggest hazards in deep mines and are equally difficult to predict. The violent process of the outburst itself, along with the scale and range of hazards following the rapid discharge of gas and rocks, requires solutions which would enable quick and unambiguous detection of the hazard, immediate power supply cut-off and evacuation of personnel from potentially hazardous areas. For this purpose, an integrated outburst detector was developed. Assumed functions of the sensor which was equipped with three measuring and detection elements: a chamber for constant measurement of methane concentration, pressure sensor and microphone. Tests of the sensor model were carried out to estimate the parameters which characterize the dynamic properties of the sensor. Given the impossibility of carrying out the full scale experimental outburst, the sensor was tested during the methane and coal dust explosions in the testing gallery at KD Barbara. The obtained results proved that the applied solutions have been appropriate. 展开更多
关键词 integrated outburst detector SENSOR model test methane detection
下载PDF
Dark Matter Particle Explorer, the First Satellite of China Space Science Pilot Project
17
作者 ZHU Zhencai 《Aerospace China》 2016年第1期4-11,共8页
The Dark Matter Particle Explorer(DAMPE) is the first high energy detector satellite in China,whose physics goal is to find evidence of the existence of dark matter particles by investigating the composition and energ... The Dark Matter Particle Explorer(DAMPE) is the first high energy detector satellite in China,whose physics goal is to find evidence of the existence of dark matter particles by investigating the composition and energy spectra of primary cosmic rays,especially those for electrons,positrons and gamma rays,over the dynamic range from 5 Ge V to 10 Te V.DAMPE is a satellite launched by China with the largest payload ratio,where the payload is composed of a BGO(Bismuth Germanate Oxide) Calorimeter,a Plastic Scintillator Detector,a Silicon Tungsten Tracker and a Neutron Detector.This paper introduces the technical scheme of DAMPE,including requirement analysis,composition,technical innovation,on-orbit status and prospect of development for the future. 展开更多
关键词 DAMPE PAYLOAD ORBIT Structure Thermal control
下载PDF
Technical Procedure Determination of Thoron Indoor Concentration by LR-115 Type II
18
作者 Nguyen Thi Thu Ha Frinh Van Giap Le Dinh Cuong 《Journal of Environmental Science and Engineering(B)》 2016年第3期109-114,共6页
Thoron (Rn-220) is an invisible, odorless radioactive gas and nine times heavier than air. Purpose of project is to set up procedure to determine Rn-220 concentration which has been carried out in laboratory using S... Thoron (Rn-220) is an invisible, odorless radioactive gas and nine times heavier than air. Purpose of project is to set up procedure to determine Rn-220 concentration which has been carried out in laboratory using Solid State Nuclear Track Detector (SSNTD) based passive detector technique. In this study, technical procedure has been applied in Karlsruhe diffusion chamber and LR-115, Type II strippable (Kodak Pathe, France) detector. The results have investigated how LR-115 work for Rn-220 by using Monazite ore to simultaneously measure Rn-222 and Rn-220. To carry out experiment, Karlsruhe diffusion chamber is used to with and without Poly-Ethylene (PE) membrane. Karlsruhe diffusion chamber with PE membrane only detect Rn-222, without PE membrane detect total Rn-222 and Rn-220. Precision evaluation by duplicate measure at 8 cm detector-source distance with relative standard deviation is less than 2.54%. Testing technical procedure, detectors have been sent to National Institute of Radiological Science (NIRS) for Rn-220 calibration exposure. After detectors have been calibration exposure at NIRS, it carried out all the following steps of procedure which set up at laboratory in 1NST, Vietnam. Finally, calibration factor calculated is 0.21 (tracks-cm2/Bq·m3·h) and constructed curve between integrated Tn-220 concentration and tracks density with factor R2 = 0.975. 展开更多
关键词 LR-115 type-II (SSNTDs) Rn-220 spark counter.
下载PDF
试探
19
作者 田田(图) 郁葱 《高中生(高考)》 2012年第7期49-49,共1页
不要试探人.免得自己被试探。
关键词 高中 语文 阅读 <试探>
原文传递
Symmetries,Integrability and Exact Solutions to the (2+1)-Dimensional Benney Types of Equations 被引量:1
20
作者 刘汉泽 辛祥鹏 《Communications in Theoretical Physics》 SCIE CAS CSCD 2016年第8期155-162,共8页
This paper is concerned with the (2+1)-dimensional Benney types of equations. By the complete Lie group classification method, all of the point symmetries of the Benney types of equations are obtained, and the integra... This paper is concerned with the (2+1)-dimensional Benney types of equations. By the complete Lie group classification method, all of the point symmetries of the Benney types of equations are obtained, and the integrable condition of the equation is given. Then, the symmetry reductions and exact solutions to the (2+1)-dimensional nonlinear wave equations are presented. Especially, the shock wave solutions of the Benney equations are investigated by the symmetry reduction and trial function method. 展开更多
关键词 Benney equation symmetry integrability exact solution shock wave solution
原文传递
上一页 1 2 下一页 到第
使用帮助 返回顶部