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电子测量仪器是电子设备行业发展的一项产业成果。电子测量仪器的出现促进了世界工业的发展,电子测量仪器的精准度是衡量一个国家科学技术水平的重要依据之一。因此,注重了解电子测量仪器的技术走向十分重要,技术创新型人才要对我国现有的技术进行及时的创新,使我国拥有最先进的技术。文章将对新一代电子测量仪器的技术特点从不同的方面进行概括,旨在加深了解电子测量仪器的发展趋势,加快我国研究与应用的步伐。 相似文献
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对现有轴孔测量仪进行改造,采用数字信号处理技术设计FIR数字滤波器,对测量信号实行软件滤波,替代原有的硬件滤波电路。测试结果表明,该数字滤波器可以满足轴孔测量的要求。 相似文献
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电子示波器是常用的电子测量仪器,它可以用来测量各种电信号的电压、电流、周期、频率、相位等参量.电子示波器也是调试、检验、修理和制作各种电子仪表设备时所不可缺少的工具.因此,示波器在生产、科研、教育等各部门都有广泛的应用.本文就示波器在实验中的基本测量进行简要的介绍. 相似文献
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对计算机辅助测试数据处理中的数字信号转换为模拟信号的复原技术进行了研究,阐述了信号复原的基本理论,分析了常用方法的原理与不足,给出了用样条函数逼近作信号复原方法在实际应用中的优点。 相似文献
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汽车电控装置普及,输入量的处理作为汽车电控的重要一环节对系统可靠性有着重要影响。分析了汽车各系统的电子电路、电子设备常见的输入量的类型,包括模拟信号、数字信号、脉冲信号;给出了根据其各自的特点所使用抑制干扰的主要方法。 相似文献
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四端法土壤电导率传感器恒流源设计与试验 总被引:1,自引:0,他引:1
土壤信息对于指导农业生产有着极为重要的作用,土壤电导率反映了土壤含水量、盐分、粘粒含量和类型等土壤信息,准确获取土壤电导率对于实现农业精细化生产意义重大。在各种土壤电导率测量方法中,四端法因其成本低、精度高、测量快速和操作简便而大量应用于实际测量;恒流源是四端法测量仪器的重要组成部分,其性能直接决定着测量仪器的精度以及测量范围。本文对比了3种恒流源对测量仪器测量性能的影响,发现采用Howland恒流源的四端法测量仪器高电导率测量能力强而低电导率测量范围较小,测量精度最高;采用改进型Howland恒流源的四端法测量仪器低电导率测量范围有所扩大,测量精度良好;采用基于差动放大器的恒流源的电导率仪低电导率测量范围最大,高电导率测量范围较优,测量精度良好。 相似文献
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频率测量是电子测量领域中最基本的测量之一.频率是描述周期现象的一个基本参量,一般称为准数字信号,频率的测量应用非常广泛.单片机具有控制和数据处理能力,分析基于单片机的等精度数字测频装置的硬件组成和工作原理,用它构成的测频仪器不但运算方便而且可以大大简化传统的硬件电路. 相似文献
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《Journal of Agricultural Engineering Research》1998,69(3):249-254
A model to represent the discolouration of dried powder of carrots as a function of temperature was developed. Two types of carrots, Asian and European, containing large amount of lycopene and β-carotene, respectively, were tested. The dried powder was stored under an atmosphere with O2and at three different temperatures, 5,20 and 35°C. The surface colour of the powder was monitored during storage by a Hunter colour ratioa/b. In the proposed model, the rate of oxidation was assumed to be represented by the product of the fraction of concentration of oxidized pigment at arbitrary time and a specific rate of oxidation of pigment. The rate parameters in the proposed model were calculated by fitting the experimental data with smooth curves by trial and error at the end of the induction period but before discolouration took place. The frequency constant and activation energy, expressing the temperature dependence of the rate parameters, were expressed by the Arrhenius relation. The simulation results of a Hunter colour ratioa/bof dried powder at 25°C showed good agreement with the experimental data, suggesting that the proposed model was effective for the prediction of discolouration of dried powder of both types of carrot. The use of the induction period in the manner described may enable the shelf life of dried powder to be predicted. 相似文献
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感官检验棉花的品级,这是农村常见的一种检测手段.它的一个主要特点就是存在不确定性.这是由于检验员的品级检验水平存在一定的差异,其中有很多因素制约着检验的结果.文章对影响感官检验结果的因素进行了系统的分析. 相似文献
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The fractional outflow rate of water from the rumen, measured as the rate of disappearance of the chromium complex of ethylenediamine tetra-acetic acid, was related to a number of dietary factors. A multiple regression equation was derived which expressed fractional outflow rate as a function of the intakes of dry matter, ash, acid-detergent fibre and crude protein.The data analysed consisted of 243 observations for sheep on 59 diets, including forage, concentrate and mixed diets. The ranges covered by the data were: fractional outflow rate 0.7–3.6 day?1; dry matter intake 560–1400g/day; ash 4–30%, acid-detergent fibre 7–41%, crude protein 5–26 % of dry matter; there were no observations for sheep of less than 34 kg liveweight.The equation accounted for 56·3 % of the total variance. Between-sheep variance could not be calculated for the whole of the data but was undoubtedly substantial since, for a sixth of the data, it was known to account for 38 % of the total variance. 相似文献
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从灾害经济学的角度探讨了城镇供水优化调度的必要性和可能性,认为在缺水不可避免的情况下,对供水进行优化调度可以减小缺水带来的损失,产生较好的减灾效益,特别是可以大大减小严重干旱的灾害效应。并根据水资源的特性,提出了缺水损失的计算模式以及优化调度的原则和方法。 相似文献