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由于SS1和SS3型电力机车设计出来时并不是作为重联机车使用,主要是做单机牵引,所以在运行中就出现了不少的缺陷.首先,机车牵引的同步性不好,不能完全利用机车的牵引力.其次,列车在制动过程中由于重联机车制动机与本务的动作过程不能一致,对整列车来说会产生不同程度的冲动,是造成断钩和列车分离的不安全因素,对于机车来说也是产生动轮擦伤和弛缓的原因.重联阀不仅可以使同型号机车制动机重联,还可以使不同类型机车重联使用,以便实现多机牵引. 相似文献
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文章阐述了SS4改型电力机车牵引缓冲装置的常见故障,并做出了相应的处理方法.文中针对车钩及车钩缓冲器的常见故障,如裂纹、变形等,分析其产生原因并列举了相应的检修要求及方法. 相似文献
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主断路器是应用于电力机车和动车组主电路接通和断开的高压电器,文章对应用于CRH5型动车组的主断路器在使用过程中出现不能闭合的现象,分析并总结了其故障原因及相应的处理措施. 相似文献
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《物流运输实务》是技术学校物流专业的主要课程,现如今很多学校在开展物流运输实务这门课程的时候出现很多问题,随着我国新课改的不断开展,人们对于物流运输实务这门课程的要求也变得越来越高。这对于高职教师而言,既是机遇又是挑战。本文针对现如今物流运输实务课程中存在的问题进行分析,并针对这些问题提出了相应解决措施。 相似文献
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本文简述了跨区作业运输费用高的现实,针对这一实际,设计一种结构简单,操作方便,安全可靠,造价低廉,可随收割机一起运输的凯斯2388型收割机装卸车装置,能很好地解决收割机的装卸车问题,在较大程度上降低运输费用。 相似文献
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随着电气化铁路里程的不断增加,提升电力机车的运行安全具有十分重要的意义.电力机车辅助机组是保证机车可靠运行的重要组件,铁路运输管理部门应对其予以重视.文章基于电力机车辅助机组的重要性,仔细分析了辅助机组中故障问题,并探讨了辅助机组故障的处理方法,希望在保证电力机车安全运行的基础上节约铁路运营成本,进而促进铁路运输行业的发展. 相似文献
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连挂式拖拉机是耕作与运输兼用型拖拉机,即主车与拖车不是一个整体,当运输时把主车与拖车用一根牵引轴连接,这就决定了整个车型在运输作业时刹车制动不可靠的现象.例如一台中型拖拉机主车不足1t,而拖车载满货后一般都有3～4t,形成了主车与拖车重量相差太大的现象,这就造成了拖拉机上下坡的操作难度,稍不注意就会出现翻车事故.为了减少事故的发生,这里介绍连挂式拖拉机载货运输上下坡的操作要点: 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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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
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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