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开发和设计了一种伸缩杆式残膜回收灭茬联合作业机。在对国内外各种残膜回收机优化组合的基础上,进行了残膜回收机的总体设计及主要部件的结构设计,着重进行了残膜回收灭茬联合作业机的传动系统与拾膜部件机构的设计。试验和理论计算表明:各项工作部件的设计和使用都是正确的,理论、试验均满足残膜回收作业要求。 相似文献
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《中国农机化学报》2015,(6)
为使水稻生产过程中的筑埂作业实现机械化,设计了一种稻田生产用可翻转式整地筑埂联合作业机。该机采用拖拉机为动力,可以进行整地和筑埂联合作业;当无需进行筑埂作业时,通过控制翻转机构,将筑埂部件升起,可以进行单独旋耕作业。该机主要由牵引架、机架、传动装置、旋耕部件、集土部件、离合器、筑埂压实部件、可翻转机构等部分组成。本文阐述了其工作原理及各关键部件的设计,说明了机器的工作状态、适应范围和主要技术指标,其所筑土埂高度为200~450mm,筑埂上顶宽200~350mm,下底宽300~650mm,作业速度1 500~2 000m/h。该机为我国水稻生产筑埂机械化提供了技术支持。 相似文献
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本文主要介绍了畦作洋葱联合整地机主要工作部件中扎孔锥的参数,对其进行研究设计和计算,并通过Design Expert软件分析,确定主要部件参数,最终确定最佳工作参数,然后根据试验最佳工作参数组合进行验证试验,结果表明此参数组合能满足膜破损率要求,同时,介绍了其整机结构及工作原理,该机现场作业时,可一次完成整地、喷药、覆膜、扎孔等高效整地机械作业,以便后续机械化栽种、收获等作业。 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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《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