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棉花是新疆玛纳斯县的一项支柱产业,每年种植面积都在2.7万hm2以上。随着我国工业化、城市化步伐的加快和人民生活水平的不断提高,农村阶段性用工矛盾不断加剧,用工成本急剧上升,棉花收获已成为影响棉花产业发展的主要因素,实现机械化收获势在必行。采用机械化收获,可极大地提高劳动生产力,降低农民劳动强度,为社会经济发展提供大量人力资源,为农村经济发展提供新的经济增长点。实现棉花机械化收获及其模式化栽培管理,是促进棉花产业发展的根本途径。 相似文献
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棉花生产在我国国民經济中占重要地位.棉花生产很費工,而收获的用工量在总用工量中所占的比重又最大,在华北棉区,特别是在棉花生产各作业項目逐步机械化以后,收获机械化的問題如果不解决,就会严重影响棉花生产的发展。例如在新疆的一些机械化程度較高的棉作农場,手工采棉的劳力非常紧張,在那里采棉机械化成为突出的现实問題。因此研究棉花收获机械有其重要意义。 相似文献
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农一师棉花全程机械化存在的问题及解决措施 总被引:1,自引:0,他引:1
棉花是新疆生产建设兵团农一师种植的主要经济作物,通过多年的发展,棉花机械收获技术已成为制约棉花全程机械化发展的主要瓶颈,本文就棉花机械收获方面存在的问题和解决措施进行具体的阐述。 相似文献
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在我国三个棉花产区中,长江中下游产棉区机械化程度最低。随着农业劳动力的大量转移,严重影响了棉花生产,发展轻简化、机械化生产已是当务之急。三湖农场在棉花机械化生产方面积极探索,除了移栽和收获外基本实现了田间管理机械化,目前正在进一步试验全程机械化技术。 相似文献
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在我国粮棉油3大经济作物中,唯有棉花一直没有实现机械化收获。介绍了黄河三角洲地区进行棉花种植的优势和棉花生产机械化的现状,分析了现阶段在该区域发展机采棉存在的问题和必要性,并提出实现棉花生产全程机械化的几点建议。 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