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玉米精量播种监测系统的设计与试验 总被引：1，自引：0，他引：1
针对玉米精播机作业时常会发生导种管堵塞、地轮排种轴机械传动系统故障及种箱排空造成的漏播等现象,基于单片机技术设计了一套玉米精量播种监测系统,包括整体结构与排种监测传感器电路,完成了相关参数设置。该系统实现了对玉米精播机的播种量、播种速度、播种面积、地轮转速、排种轴转速、种箱料位及机具升降状态等指标的实时监测和漏播故障诊断功能,支持对精播机作业数据远程实时监控管理功能。试验结果表明:玉米精量播种监测系统单粒测量精度约为98.8%,能够实现作业过程的实时监测及远程监管功能。 相似文献
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2BFJ-24型小麦精量播种变量施肥机设计与试验 总被引：4，自引：0，他引：4
为了提高冬小麦播种质量与种肥利用率,降低生产成本,针对中原地区冬小麦适度规模种植种肥同播作业方式粗放、效能低的特点,基于CAN总线通信协议下的车载传感器与PIC控制融合技术,设计了2BFJ-24型小麦精量播种变量施肥机,由播种施肥机械部件、种子漏播监测系统、肥料堵塞监测系统、变量施肥控制系统及车载计算机组成。通过红外光电检测可实时监测排种管种子流量情况,通过检测排肥管下端口内介电常数变化可实时获取肥料下落信号;通过集成GPS模块获取机器田间位置信息,结合预先加载的田块处方图,确定当前位置目标施肥量,并基于压力传感与微机控制解算当前施肥量和流量信息,按照机器前进速度实时调整施肥量;最终实现作业过程漏播、堵塞声光报警与精准施肥目的。田间试验结果表明,整机监控系统能够适应复杂田间环境,漏播监测准确率可达91%,肥料堵塞报警误差小于2%,变量施肥准确率超过96%,具有较好的实用性和经济性。 相似文献
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《中国农机化学报》2016,(3)
针对现有机械式玉米精密播种施肥机播种施肥一致性差、肥管易堵塞、种子重播漏播严重、无补种机构等问题,研制基于DSP控制技术的智能玉米精密播种施肥机。实现精密播种施肥机工作过程中种肥的实时监控及故障处理,统计已播、重播、漏播种子数及施肥量等数据,当发现漏播时能即时补种;当出现肥料堵塞时能即时疏通;种箱缺种和肥箱缺肥能发出声光报警。同时,可以通过触摸屏设定播种株距及施肥量。田间试验表明,整机结构稳定,重播、漏播、缺种、缺肥、肥管堵塞报警率达100%,肥管堵塞疏通率达100%,并且安装补种系统后,总播种率达到99.4%,相比没有加补种系统前提高5.8个百分点。 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