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1WG-4.4A型多功能微耕机是适用于山区坡田地块耕作的农业机械。阐述该微耕机的结构特点、作业性能与主要技术参数,介绍该机具的多种作业功能,分析应用该机具的作业效果与经济效益,为其大面积推广提供理论与技术支持。 相似文献
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为了满足深松和耙地同时作业的需求,在吸收国内外先进技术基础上,创新研究设计了集深松、耙地、碎土于一体的松耙联合整地机,该机主要由切草装置、弧形深松铲和圆盘耙组组成.通过作业实验机具性能,结果表明该机具具有作业效率高、节约能耗、降低成本、作业效果好等优点,深松耙地作业后的各项性能指标均能满足作业标准的要求. 相似文献
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为解决现有深松整地机具存在的问题,设计一种深松联合整地机。阐述该机具的工作原理与整体结构,详细介绍其主要工作部件的设计思路。该机具结构合理,作业阻力小,整地效果好,作业效率高,使用寿命长,适应性强。 相似文献
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概述玉米节水灌溉覆膜播种作业的技术条件,介绍相关机具的组成及主要结构,总结该技术在辽宁地区的推广应用效果,为提高干旱地区玉米产量提供技术及机具参考。 相似文献
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开沟机是农业生产中常用的小型作业机具.针对现有开沟机具在实际生产中存在的开沟效果不理想的问题,根据开沟装置的结构特点,对其关键工作部件进行结构分析与优化设计,以改进开沟机的性能,提高作业可靠性. 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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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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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