共查询到20条相似文献,搜索用时 78 毫秒
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农业节水公司托管服务模式效果评价指标体系研究 总被引:1,自引:0,他引:1
《节水灌溉》2016,(3)
针对新疆部分县市农业高效节水灌溉技术运行效率不高的问题,成立了专业化的节水灌溉服务公司,逐步形成了一套"政府+企业+农户"的集约化农业高效节水灌溉运行管理模式。运用逻辑框架法构建涵盖影响、效果、结果和措施四个层次的指标体系来评价农业高效节水公司托管服务模式的实施效果,为今后全疆尤其是南疆地区推广该模式提供参考和借鉴。 相似文献
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新疆干旱地区农业用水利用研究 总被引:5,自引:3,他引:5
节水农业一直是新疆干旱地区农业发展追求的一个主要目标,国内外各种节水灌溉技术在这一地区得到了广泛应用。根据新疆的水资源状况,指出要解决新疆水资源可持续利用问题,关键是解决农业用水的高效合理利用。提出了干旱地区实现水资源可持续利用及高效节水生态农业的措施。 相似文献
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新疆高效节水灌溉发展规模研究 总被引:1,自引:0,他引:1
目前,新疆农业节水型灌溉面积占总灌面积46.5%,高出全国平均水平8.4%。在高效节水面积中,微灌比重65.73%,高出全国56.8%;渠道防渗面积比重48.1%,高出全国30.2%。节水灌溉的较快发展,为极为干旱的内陆新疆水资源可持续利用,优化配置经济用水结构调整目标发挥着重要作用。基于今后所关注的新疆农业灌溉系统节水灌溉发展规模、系统结构、主要推广的节水模式等问题,采用系统工程技术方法规划研究。结果表明,微灌和低压管灌是农业高效节水发展主体,与目前推广微灌等高效节水现状相吻合。为"十二五"加大农田节水发展规模提供了技术参考。 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