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植保作业通过植保机械代替了传统的人工作业模式,显著提升了植保过程的效率与安全性。在传统普通轮式植保机械的基础上,为进一步提升植保作业的效率和质量,无人机植保的应用范围得到扩大,其具有明显的技术优势,且在应用过程中得到了广大农民的认可。 相似文献
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植保作业能够有效减少农作物生长过程中的病虫害损失,有利于保证农业生产的经济效率和最终产量,通过对农业植保机械的发展过程进行说明与分析,总结了现阶段植保机械作业过程中存在的问题,希望对我国的植保机械的技术水平和作业规范有所帮助。 相似文献
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我国是烟草种植大国,植保作业是烟草种植过程中必不可少的环节,植保机械是植保作业的重要载体.对国内外烟草植保机械的研究和发展现状进行了综述,分析了国内烟草植保机械同发达国家植保机械之间存在的差距,说明了烟草植保机械未来的发展趋势. 相似文献
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为提高农业植保作业效率,降低病虫害对农作物生长造成的威胁与影响,笔者分析了无人机农业植保作业的优势,并对无人机农业植保作业的关键技术展开研究。为满足无人机农业植保作业需求,笔者提出了应在作业前,选择水基类型的药剂,包括水乳试剂、微乳化试剂、悬浮试剂、乳油试剂,合理配置无人机农业植保作业药剂;从高压扇形喷头喷药量、喷药速率、行距等方面设计喷洒作业技术参数;使用三相交流无刷电动机,建立无人机农业植保作业的动力系统,实现在喷洒过程中对无人机作业动力与飞行的集中控制。实验结果表明:采用该无人机农业植保作业方法,可以使农药喷洒作业效率达到10 hm2/h以上,对区域内害虫的消灭率可达到95%以上。 相似文献
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针对我国传统的植保机在精准化作业和自动化喷洒方面存在的不足,基于计算机数据融合算法对植保机精准化作业进行了设计试验。植保机的主要组成包括控制单元模块、信息采集模块、传感器模块、数据传输模块和变量执行器模块。为了实现植保机的精准化作业,对植保机的飞行姿态调整和变量喷药过程进行了算法设计。其中,飞行姿态控制采用双闭环位置式PID控制算法,喷药过程采用改进的遗传PID控制算法进行控制。为了验证植保机精准化作业的效果,对其进行姿态控制和变量喷药试验。结果表明:植保机姿态控制良好,能够完成精准化喷药。 相似文献
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植保是我国水稻全程机械化生产过程中较薄弱的环节,对水稻无人直升机植保和半机械化植保两种模式开展了对比试验。结果表明,无人机植保工作效率是半机械化作业的16倍,节省农药成本26.4%,节省单位面积总成本23.42%;同时,无人机植保还具有喷洒均匀、雾化效果好、环保效果好和安全系数高等优点。水稻无人机植保将是替代传统半机械化作业的重要模式之一。 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