共查询到20条相似文献,搜索用时 62 毫秒
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中部地区是我国重要的经济枢纽,但"中部塌陷"问题使其可持续发展动力不足.为探究高质量发展背景下该地区资源与社会经济发展的关系,本研究以五大发展理念为基准层构建绿色发展指数,运用SBM模型评估了2003-2018年中部地区水资源利用效率,并利用Tapio脱钩模型探究不同阶段中部地区社会经济发展与水资源的关系.研究表明:中... 相似文献
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研制一种电驱动多功能果园作业平台,该平台以电动机替代内燃机,有三种控制模式,搭载不同配件,能高效完成采摘、修剪、运输、称重、自卸等作业,可实现一车多用.经试验,该平台安全性能满足DG/T 212-2019《果园作业平台》要求,各项性能指标均达到设计要求. 相似文献
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【目的】验证不同源汇型农作景观组合对削减农田泥砂、氮、磷排放的效果。【方法】于2014—2017年在浙江省选择蔬菜地-茭白田、蔬菜地-水田、果园-茭白田、桑园-水田和果园-荷塘等5种南方地区有代表性源汇型农作景观组合模式,进行定位观察,比较分析了其对泥砂量、总磷量、可溶性磷量、总氮量和可溶性氮量的减排效果。【结果】与"汇"处理前的"源"农田比较,5种源汇型农作景观组合农田泥砂和养分流失削减比例均在70%以上,平均削减率总磷量(90.63%)>可溶性磷量(89.14%)>泥砂量(88.72%)>可溶性氮量(86.75%)>总氮量(86.64%)。5种景观组合对削减排水中泥砂量、总磷量、可溶性磷量、总氮量、可溶性氮量的效果表现为果园-荷塘>蔬菜地-茭白田>果园-茭白田>桑园-水田>蔬菜地-水田。【结论】源汇型景观组合对污染物的削减主要通过减少排水与对污染物吸收、吸持来实现,是一种方便、低廉、高效的农田系统养分流失控制技术;并以"汇"为荷塘或茭白的组合模式效果为佳。 相似文献
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基于Zigbee技术的果园生态环境监测系统 总被引:6,自引:1,他引:5
针对我国水果生产管理水平较低、尚无科学的方法实时监测果园生产环境和果树生长状况的现状,提出了一套无线实时监测果园生态环境的方案.该方案基于无线通信协议Zigbee技术,采用Microchip公司的Zigbee协议栈和开发平台,构建了星型无线传感器网络.以温度数据采集为例,介绍了无线传感器数据采集单元;研究分析了Zigbee协议栈网络的形成过程及数据采集发送程序,该程序完成温度数据采集,并无线发送.测试证明,该方案实现环境参数无线采集,为果园环境监测提供了有效的解决方案. 相似文献
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赣南地区果园经济条件下水土保持研究进展 总被引:1,自引:0,他引:1
《南方农机》2017,(21)
果园经济已经成为赣南地区的支柱产业,而由果园开发造成的水土流失已经成为赣南地区水土流失的重要来源,本文从果园土壤侵蚀形成机理、果园水土保持措施和果园生态效益3个方面总结了果园经济下的水土保持的研究进展,提出了今后应开展的研究重点,旨为果园"林下流"的深入研究和果园经济发展及生态环境治理提供参考。 相似文献
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为解决果园苹果采后运输设备自主导航模式单一、无法在任意点起步或停车等问题,设计了一种双导航模式小型果园运输机器人,可根据需求选择行人引领导航或定点导航。根据选择的导航模式,采用基于OpenPose人体姿态识别的目标跟踪控制方法或基于RTK-GNSS(Real time kinematic-global navigation satellite system)的距离-方向控制方法,实现果园环境下的行人引领导航和定点导航。该运输机器人以额定负载为200 kg、速度为0.5 m/s的条件参数在果园自主作业时,行人引领导航模式下目标跟踪误差平均值小于9 cm,其标准差小于4 cm;定点导航模式下到达目标点的相对误差小于13 cm,其标准差小于1.5 cm,绝对误差小于7 cm,其标准差小于0.5 cm;定点导航模式下机器人急停避障的行驶路径与理想行驶路径间的横向偏差小于56 cm,航向偏差小于8°。试验结果表明,该机器人能满足果园自主运输和安全避障的需求。 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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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
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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