共查询到20条相似文献,搜索用时 93 毫秒
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本文重点论述了目前配网自动化系统中的主要通信技术及其应用现状,比较了几种常用通信方案的特点,着重叙述了光纤通信技术在配网自动化系统中的应用。同时,探讨了几种新的通信技术在未来配网自动化中应用的发展趋势。 相似文献
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汽车电动助力转向系统发展综述 总被引:2,自引:0,他引:2
综述了国内外汽车电动助力转向(EPS)系统的发展现状,介绍了电动助力转向系统的结构、类型及其特点。分析对比了国内外电动助力转向系统建模及控制策略,展望了电动助力转向系统的发展趋势,指出电动助力转向技术代表未来汽车动力转向技术的发展方向之一,并将在动力转向领域占据主导地位。 相似文献
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结合当前国内无人机发展趋势,针对无人机系统的发展方向、发展目标、主要发展技术以及无人机应用市场及无人机应用人才的需求,可以看出无人机发展趋势逐渐提升,在未来几年有望解决部分大学生就业难问题。基于此,文章分析了正德职业技术学院无人机专业学生的就业情况,供同行们参考。 相似文献
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文章阐述PLC技术的工作原理和特点,重点分析PLC技术在电气自动化控制中的应用。从输煤自控系统、火电系统、智能交通系统三个方面具体说明,探讨PLC技术的应用实践和未来发展趋势。 相似文献
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机电一体化技术是一项多功能的综合性技术,一般有:自动控制技术、机械技术、计算机技术、系统技术、信息处理技术、伺服传动技术以及检测传感技术等,该项技术是一种密集型的系统工程。最新一代的机电一体化技术中采用的CNC系统,该系统具有智能化、高性能、为量化以及系统化、轻量化等诸多优势,机电一体化技术的发展这标志着我国科学技术发展的光辉未来。文章将机电一体化技术作为主要的研究对象,对其在我国的发展、应用以及未来发展趋势进行了详细的分析和探讨。 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