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为提高输电线路更换耐张合成绝缘子效率,保证更换后耐张合成绝缘子满足输电线路工程标准规范的要求,研制一种更换耐张合成绝缘子辅助工具。该工具主要包括挂钩单元、连接单元和主体单元3部分。在检修人员开展更换耐张绝缘子前须通过挂钩单元实现与铁塔侧及导线侧的连接,在更换过程中须保证检修人员坐在主体单元上稳固进行更换耐张绝缘子工作,同时依靠连接单元将挂钩单元与主体单元进行有效连接。实验结果表明,该辅助工具能够有效改善输电线路耐张合成绝缘子更换质量,提高更换效率和设备管理水平,具有良好的推广应用价值。 相似文献
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耐张线夹是用来将导线或避雷线固定在非直线杆塔耐张绝缘子串上的金具。输电线路运行过程中，耐张线夹锈蚀、发热、断裂等问题时有发生，线夹断裂问题直接威胁输电线路的安全稳定运行，因此，加强耐张线夹断裂原因分析尤为重要。文章对某500 kV线路导线耐张线夹引流板根部断裂原因进行了分析，提出了相应的治理防范建议，为类似事件的分析与处理提供参考。 相似文献
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通过对复合绝缘子运行情况的分析和研究,以技术角度入手对运行问题展开探讨,并根据结论对复合绝缘子今后在特高压输电线路中的应用前景展开分析,旨在提高复合绝缘子的应用水平,推动我国特高压输电线路发展。 相似文献
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<正>1研制背景杆塔上的绝缘子串按排列方式分为悬垂绝缘子串和水平绝缘子串。下雨时,由于水平绝缘子串呈水平排列,绝缘子上污垢会被雨水冲刷干净,不需要清扫;而悬垂绝缘子串呈垂直排列,雨水无法冲刷到绝缘子底部的凹槽,因此需要定期清扫。日常的输电线路绝缘子清扫工作是在线路停电的情况下,派人登杆攀爬到绝缘子串上,使用手套和毛巾对绝缘子进行擦拭。 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