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Implement of FLEX and POCSAG Pager Testing System 被引量:2
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作者 Luo Kun Huang Ji-wu +1 位作者 Yuan Lan-ying Wang Lai-yun 《Wuhan University Journal of Natural Sciences》 EI CAS 1999年第3期322-325,共4页
The synthesized signal testing equipment is widely used in the field of wireless communication. A new design method of FLEX and POCSAG page testing instrument is introduced, which is based on MCU encoder, FPGA control... The synthesized signal testing equipment is widely used in the field of wireless communication. A new design method of FLEX and POCSAG page testing instrument is introduced, which is based on MCU encoder, FPGA control and digital RF. The technology of DDS and PLL is also presented. 展开更多
关键词 pager testing instrument FLEX FPGA PLL DDS
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Feasibility study applied to mapping tidal effects in the Pannonian basin--An effort to check location dependencies atμGal level 被引量:1
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作者 G.Papp J.Benedek +5 位作者 P.Varga M.Kis A.Koppan B.Meurers R.Leonhardt M.K.Baracza 《Geodesy and Geodynamics》 2018年第3期237-245,共9页
This paper summarizes the main instrumental and methodological points of the tidal research which was performed in the framework of the National Scientific Research Fund Project K101603. Since the project is still run... This paper summarizes the main instrumental and methodological points of the tidal research which was performed in the framework of the National Scientific Research Fund Project K101603. Since the project is still running the tidal analysis results published here are only preliminary. Unmodelled tidal effects have been highlighted in some recent absolute gravity measurements carried out in the Pannonian basin resulting in a periodic modulation exceeding the typical standard deviations (±1microGal) of the drop sets. Since the most dominant source of the daily gravity variation is the bulk tidal effect, the goal of the project is to check its location dependency at BGal level. Unfortunately Hungary has had no dedicated instrumentation, so an effort was made to make the available LaCoste- Romberg spring G meters capable for continuous recording. As a reference instrument the GWR SG025 operated in the Conrad Observatory, Austria was also used and in the mean time of the project, a Scintrex CG-5 became also available, Eventually 6 instruments at 5 different locations were operated for 3 9 months mainly in co-located configuration. Although many experiments (moving mass calibrations) were done to determine the scale factors and scale functions of the instruments, the direct comparison of the tidal parameters obtained from the observations is still questionable. Therefore the ratio of the delta factors of O1 and M2 tidal constituents was investigated supposing that M2 is much more influenced by the ocean loading effect than O1. The slight detected increase of δ(O1 )/δ(M2) (≈0.2%) toward east does not contradict to theory. This result has to be validated in the near future by analyzing available ocean loading models. 展开更多
关键词 Gravity tide mapping Spring gravity meters Instrumental tests Co-located observations Location dependence of delta factors
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Characteristics and Performance of the CCD Photometric System at Lulin Observatory 被引量:1
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作者 DaisukeKinoshita Chin-WeiChen +4 位作者 Hung-ChinLin Zhong-YiLin Kui-YunHuang Yung-ShinChang Wen-PingChen 《Chinese Journal of Astronomy and Astrophysics》 CSCD 2005年第3期315-326,共12页
The Lulin One-meter Telescope at Lulin Observatory in Taiwan started open-use observations in January 2003. In order to evaluate the performance of the CCD photometric system, the characteristics and quality of the si... The Lulin One-meter Telescope at Lulin Observatory in Taiwan started open-use observations in January 2003. In order to evaluate the performance of the CCD photometric system, the characteristics and quality of the site, we obtained data of photometric standards as well as calibration data from February to November 2004. We report here the results of our analysis including the gain, readout noise, dark current and linearity of the CCD camera, and transformation coefficients, total throughputs, night sky brightnesses and limiting magnitudes for UBVRI bands. 展开更多
关键词 instrumentation: miscellaneous - site testing - telescopes
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Environmental simulation platform and its application to geodesic instruments for a performance study
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作者 Tu Hai-Bo Sun Heng +4 位作者 Liu Kun Zhang Jun-Gang He Jian-Gang Tian Wei Wang Yong 《Applied Geophysics》 SCIE CSCD 2020年第5期756-763,902,共9页
In this study,an environmental simulation platform(ETS-02)was constructed for high-precision geodesic instruments(e.g.,absolute/relative gravimeters and inclinometers),to test the disturbances caused by environmental ... In this study,an environmental simulation platform(ETS-02)was constructed for high-precision geodesic instruments(e.g.,absolute/relative gravimeters and inclinometers),to test the disturbances caused by environmental fl uctuations.The outer layer of the platform was constructed with two sets of rectangular electromagnetic coils,which generated the required magnetic fi eld when current was applied.The inner layer was a closed cabin in which radiators were distributed such that the temperature of the experimental space inside the cabin could be controlled,by energy exchange between the radiators and a thermal controller through the fl owing liquid.A high-precision hexapod was used to simulate the tilt-related eff ect.The platform was capable of adjusting temperatures within a dynamic range of 0℃-70℃ at a resolution of 0.01℃.The noise of the power-spectrum density when the cabin was set to room temperature was measured as 0.03℃/Hz^(1/2) at 1 mHz.The magnetic field simulation had a dynamic range of±300μT and stability of 20 nT.The resolution of the ground-tilt simulation was 1 arc s.The inner space of the platform had a volume of approximately 5 m^(3),which is sufficient for most types of instruments to be tested for a general environmental coupling effect.To illustrate the application of the platform,a dual-axis inclinometer was built and tested carefully with the platform,and the accuracy of the calibration factors was found to be signifi cantly improved. 展开更多
关键词 Environmental simulation platform temperature magnetic fi eld ground tilt dual-axis inclinometer test of geodesic instruments
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Modified Coffin-Manson equation to predict the fatigue life of structural materials subjected to mechanical-thermal coupling non-coaxial loading
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作者 Zhichao Ma Chaofan Li +4 位作者 Wei Zhang Shenghui Wang Jiakai Li Hongwei Zhao Luquan Ren 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2023年第29期118-127,共10页
With regard to the structures subjected to severe mechanical-thermal coupling fatigue conditions,the consistency between service conditions and loading conditions was the prerequisite for the fatigue prop-erties test ... With regard to the structures subjected to severe mechanical-thermal coupling fatigue conditions,the consistency between service conditions and loading conditions was the prerequisite for the fatigue prop-erties test and fatigue life prediction.A miniature piezoelectric-driven instrument integrating with a tripodal piezoelectric actuator and envelope-type heating function was developed to investigate the mechanical-thermal coupling fatigue properties and obtain the fatigue life of materials under approximate service conditions.A physical model was described to quantitatively calculate the alternating deformation under the mechanical-thermal coupling tensile-bending combined condition.Accordingly,a fatigue life prediction method based on the Coffin-Manson equation under tensile-bending combined loading was proposed to estimate the mechanical-thermal coupling fatigue life in terms of the total coupling defor-mation and plastic strain amplitude.The feasibility of the proposed instrument was verified through the analysis of displacement responses of high entropy alloy specimens under the thermal-mechanical cou-pling tensile-bending combined condition at temperatures ranging from RT to 600°C.The comparison between fatigue lives directly measured through thermal-mechanical coupling experiments and theoreti-cally predicted fatigue lives indicated the availability of the modified Coffin-Manson equation. 展开更多
关键词 Fatigue testing instrument Mechanical-thermal coupling Combined loading Fatigue life prediction odified Coffin-Manson equation
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