共查询到20条相似文献,搜索用时 62 毫秒
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农业机器动态折旧的研究 总被引:3,自引:0,他引:3
提出农业机器折旧应遵循等值原则,并运用资金时间价值分析法,给出了动态折旧的一组公式,省去了固定资金占用费的计算,化简了固定资金回收方法,保证了资金的足额回收 相似文献
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农业机器系统的选型是指对农业机器大小的选择,而配备是指对所选型号在数量上的协调。目的是按农艺要求确定合理的动力机械和作业机械数量,构成一个整体状态合理的农业机器系统,从而高效率、高质量、低成本的完成农业生产作业任务。 相似文献
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本文在回顾和分析国内外农业机器系统研究成果的基础上,阐述了农业机器系统研究中优化目标的确定方法、优化技术的主要手段。文章在分析了发展农机化与构建和谐社会的内在联系及阻碍农机化发展进程的因素的基础上,提出了我国农业机器系统研究中应解决的主要问题。 相似文献
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在我国的农业生产中农业机器的选型主要靠经验,选择合适的农业机器并对其系统进行优化将能更好地满足生产、节约成本。文章将介绍农业机器的选型与系统优化的要点。 相似文献
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分析了目前使用的农业机器偿还基金折旧法(复利法)存在的问题;推导出存在通货膨胀的折旧基金的计算方法;并通过实例比较改进前后的两种计算方法。结果表明,当存在通货膨胀时,只有提高每年提取的折旧基金,才能保证农业机械折旧基金的足额回收。 相似文献
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农业机器系统配备的线性规划法的建模方法改进与分析 总被引:2,自引:2,他引:2
本文对目前农业机器系统配备的线性规划法的建模进行了深入分析,指出了在建模时存在的不足,在此基础上,提出了改进农业机器系统配备的线性规划建模方法。 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