共查询到20条相似文献,搜索用时 31 毫秒
1.
船舶管系减振材料的应用研究 总被引:1,自引:1,他引:0
为适应我国舰船减振降噪的需要,试制出QGD-1和QGD-2两种穿孔型隔振垫,主要用于管路马脚,也可用于基座等振动部位。对两种隔振垫的阻尼性能、阻燃性能、耐油性能与国外同类产品进行了比较。经管路模型试验和水泵机组试验证明,这两种隔振垫可使管路系统振动加速度级明显下降。 相似文献
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Yamamura K. Inoue T. Yokoshima I. 《IEEE transactions on instrumentation and measurement》1988,37(2):277-279
A dry monoload microcalorimeter and standard barretter mounts with effective efficiencies exceeding 85% have been used in the development of a 94-GHz power standard. The effective efficiencies of the standard barretter mounts are measured by a calorimeter with an uncertainty of 0.16%. A bolometer mount under test is calibrated to the standard barretter mounts with an uncertainty of 0.23%. Measurements and calibrations are fully automated using a desk-top computer 相似文献
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《IEEE transactions on instrumentation and measurement》1973,22(2):166-173
Two-port coaxial mounts to measure power, voltage, and current from audio to 36 GHz are described. These mounts need no RF calibration (thus eliminating accuracy degradation in the calibration hierarchy) and remove serious difficulties in measurements and equipment evaluation. 相似文献
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半主动控制电流变液压悬置隔振性能仿真研究 总被引:2,自引:0,他引:2
对半主动控制式电流变液压悬置的结构及工作原理进行了描述,考虑阻尼通道及电流变液的特性,建立了该悬置的动力学仿真模型.选择模糊控制作为控制算法,通过仿真计算研究了该悬置的隔振性能.利用ADAMS软件,建立了汽车动力总成悬置系统的六自由度动力学模型,对采用半主动控制式电流变液悬置的动力总成系统进行了仿真研究,并将其结果与采用被动悬置的动力总成系统的振动特性进行了比较分析.研究结果表明:施加控制之后,动力总成的振动将大为降低,这说明采用半主动控制式电流变液压悬置能很好地改善悬置的隔振性能. 相似文献
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The general equations for parameters of concave grating mounts that provide stationary and superstationary astigmatism at the wavelength of correction are derived for the first time, to the best of our knowledge. These can be used to design grating multi/demultiplexers for wavelength-division multiplexed optical communication systems and high-resolution, narrow-band spectrographs. Important special cases of stationary anastigmatic mounts and their performance are presented. 相似文献
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Achkar J. Velasco L. Weidman M.P. Clark R.F. Jeong Hwan Kim Jeong Il Park Tieren Zhang Peters J.E. Ruehaak J. Stumpe D. de Vreede J.P.M. Wallace A.M. 《IEEE transactions on instrumentation and measurement》1999,48(2):169-173
A measurement comparison of effective efficiency has been carried out between eight national metrology laboratories at 33 GHz in rectangular waveguide IEC R320. Two waveguide thermistor mounts were measured. The following national laboratories participated: BNM-LCIE (France), NIST (U.S.), NRC (Canada), KRISS (Korea), CSIRO (Australia), PTB (Germany), NMi VSL (The Netherlands), and NPL (U.K.). The Bureau National de Metrologie-Laboratoire Central des Industries Electriques (France) acted as the pilot laboratory for the comparison. Excellent harmony is observed between results given by the participants, especially for the item LCIE-92021 相似文献
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弹性安装条件下机器结构声功率流的现场测量 总被引:3,自引:0,他引:3
本文利用互功率谱的方法对安装在混凝土地板上的小型排气扇工作时产生的结构声功率流进行了现场测量。对不同劲度系数的隔振支架对结构声功率流的影响进行了比较。 相似文献
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Yokoshima I. Geneves G. Ide J.P. Inoue T. Weidman M.P. 《IEEE transactions on instrumentation and measurement》1989,38(4):927-929
An international comparison of power standards at 94 GHz was approved at the 1983 meeting of the Radio Frequency Working Group of the Consultative Committee on Electricity, Participants in the comparison were ETL (the pilot laboratory, Japan), LCIE (France), NIST (US), and RSRE(UK). Three thermistor mounts as the transfer standards were circulated among the participants, who measured the effective efficiencies of the mounts. Relative deviations in power measurements at 94 GHz by the participants lie within a range of 1.3% 相似文献
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This paper reports the characterization of four meat and bone meal (MBM) ashes obtained from specific incineration (laboratory) and from co-incineration (industrial process). Three out of the four MBM ashes were mainly composed of calcium phosphates (hydroxyapatite and whitlockite). Their compositions (major and trace) were in the range for natural phosphate rocks. Trace element contents, including heavy metals, were below 0.6% and industrial ashes contained much more heavy metals than laboratory ash. The amounts of leached elements were low, especially for laboratory ash. According to the European classification of waste to be landfilled, the laboratory ash can be classified as an inert waste. Two industrial ashes are mostly inert. Only one ash is highly leachable and needs a stabilization treatment to be classified at least in the category of hazardous waste. It seems, from these results, that possibilities other than landfilling could be considered to give economic value to these ashes. 相似文献
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《IEEE transactions on instrumentation and measurement》1984,33(4):269-275
Automated calorimeters and microcalorimeters used by the CSIRO Division of Applied Physics as primary standards of radio frequency power and voltage and for measuring the effective efficiency of bolometer mounts are described. Methods for evaluating corrections from computer models of the thermal and electrical circuits and results of measurements and intercomparisons are presented. 相似文献
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测试了橡胶试片在单轴向拉伸、等双轴拉伸和平面剪切应力-应变状态下的应力-应变关系。利用测试得到橡胶试片在不同状态下应力-应变关系,和应用不同的本构模型,拟合得到了不同模型的材料常数。以两个橡胶悬置为研究对象,对橡胶隔振器进行三向静态力-位移特性分析,并与测试值进行对比。橡胶悬置1主要承受拉压变形或剪切变形,而悬置2则同时承受拉压和剪切变形。以悬置1和悬置2为研究对象,应用Mooney-Rivlin本构模型,计算分析了利用不同应力-应变状态得到的本构模型常数对橡胶隔振器力-位移关系计算结果的影响。以悬置2为研究对象,采用同一种应力-应变状态获取的本构模型常数,分析了本构模型对橡胶隔振器静态力-位移特性计算结果的影响。 相似文献
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V形橡胶减振器静刚度研究 总被引:4,自引:0,他引:4
本文讨论了V型槐胶减振器的静刚度特性。考虑到橡胶材料为超弹性材料采用T.L法进行了非线性数值计算,计算结果表明采用超弹单元进行的数值分折与实验结果接近。 相似文献
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《IEEE transactions on instrumentation and measurement》1965,14(3):102-106
A new broadband coaxial thermistor mount is described which has as its major feature the virtual elimination of a dc to RF substitution error commonly encountered in the measurement of the RF power. Secondary features include the simplicity of the design and the potential ease of matching thermistors for temperature-compensated power measurements. The termistor mount utilizes a single center tapped thermistor in place of the two thermistor beads normally used in coaxial mounts. The data taken on the thermistor mount indicate the elimination of an error described in detail in a paper by Glenn Engen, "A dc-RF Substitution Error in Dual Element Bolometer Mounts." Typically, this error is in the order of 1 percent at 10 mW and 2 percent at 15 mW of applied RF power for conventional dual bead thermistor mounts, and is due to the two beads having different dissipation constants and a shift in resistance when RF power is applied. Measurement of resistance shifts and the dissipation constants of the respective sections of the thermistor for a number of tapped thermistor beads and mounts have been made. The results indicate that this substitution error is typically reduced to below 0.1 percent up to 15mW of applied RF power. The error calculation is based upon a derived expression for the substitution error. A coaxial thermistor mount is described which is usable at RF frequencies up to 12.4 Gc/s. 相似文献
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Long-baseline, high-finesse Fabry-Perot interferometers can be used to make distance measurements that are precise enough to detect gravity waves. This level of sensitivity is achieved in part when the interferometer mirrors are isolated dynamically, with pendulum mounts and high-bandwidth cavity length control servos to reduce the effects of seismic noise. We present dynamical models of the cavity fields and signals of Fabry-Perot interferometers for use in the design and evaluation of length control systems for gravity-wave detectors. Models are described and compared with experimental data. 相似文献
19.
Dynamic design and vibro-acoustic modelling issues for automotive structures are illustrated via two case studies. The first
case examines the role and performance of passive and adaptive hydraulic engine mounts. In the second, the importance of welded
joints and adhesives in vehicle bodies and chassis structures is highlighted via generic ‘T’ and ‘L’ beam assemblies. In each
case, analytical and experimental results are presented. Unresolved research issues are briefly discussed. 相似文献