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介绍了一种新型喷灌和软管灌溉两用轻小机组的结构和工作原理,该新型灌溉机组由绞盘车提供行走动力和压力水源,通过喷水车进行喷洒灌溉.机组可配置喷灌和软管灌溉两种不同的灌水系统,满足了不同作物在不同生育期对水分的要求;喷水车安装有高度调节装置,始终使灌水器处于最佳灌水高度;机组上采用低压折射式喷头和软管洒水带等低压灌水系统,使机组的工作压力降低了30%.通过对该机组水涡轮特性、运行特性、喷洒特性的分析,确定了该机组的技术参数.喷洒试验表明,新型灌溉机组可克服受风影响较大的弱点,减少灌溉水分的漂移损失,灌水均匀度可达90%. 相似文献
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李斌 《中国农村水利水电》2018,(10)
针对地埋式滴灌这一新兴高效节水技术在民勤绿洲推广应用中存在的技术难点,从滴头流量选择、滴灌带埋设深度、铺设间距三方面开展试验研究,分析了生育期土壤水分变化情况及玉米穗物理指标、产量,提出了适合民勤绿洲生产实际的地埋式滴灌技术参数,解决了地埋式滴灌推广应用中的实际问题,提高了水资源利用效率,节约了有限的水资源,为保护民勤绿洲生态环境不再恶化起到了积极的作用。 相似文献
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《中国农机化学报》2017,(6)
研究大田水肥一体化微喷灌系统喷水性能,针对微喷带沿程喷水均匀性差异问题,采用工程系统仿真软件AMESim对单条微喷带及微喷灌整体系统进行建模仿真,分析典型型号微喷带的管径、孔径及布放坡度对喷水均匀性的影响,以及微喷带分组灌溉的效率问题,结果表明:N63型微喷带沿程压力损失小于N45和N50型微喷带;N45型0.5mm孔径微喷带沿程压力损失小于0.9mm和1.2mm的微喷带;坡度布放时应采取首端高于末端的铺设方式,且布放坡度为12°时沿程喷水均匀性最优;在不超过干管额定压力情况下,N45型微喷带采用7条一组的分组灌溉方式效率最优。此外,特别针对性价比较高的N45型0.5mm孔径微喷带开展了大田微喷灌试验,结果表明N45型0.5mm孔径的微喷带有较好的均匀性,从而验证了仿真实验结论的有效性。 相似文献
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本文提出了轮式拖拉机单油缸带梯形的全液压转向系统理论角传动比计算公式,分析了各结构参数对角传动比的影响,对其计算公式,在试验台上进行了试验验证,继而提出了一个新的技术参数——理论和实际角传动比平均相对偏差以及相应的试验方法。 相似文献
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棉花膜下滴灌技术在石河子市的应用研究 总被引:1,自引:1,他引:0
对石河子垦区近几年膜下滴灌技术大面积推广应用中存在的问题进行了分析,结合滴灌技术在大田棉花应用中种植模式和滴灌带布置方式的变化,对大面积推广应用中采用的2种布管模式进行了比较,提出了相应的应用措施,并对今后滴灌技术的进一步应用提出了建议。 相似文献
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滴灌与喷水带灌溉对香蕉生长及水肥利用的影响 总被引:6,自引:0,他引:6
通过田间试验探讨了滴灌施肥、喷水带灌溉加人工撒肥、常规灌溉施肥3种水肥管理方式对香蕉生长及水肥利用的影响,并对3种灌溉施肥方式下的经济效益进行比较。结果表明:与常规灌溉施肥及喷水带灌溉加人工施肥方式相比,通过滴灌施肥系统进行灌溉和施肥能显著促进香蕉生长发育,增加香蕉各部分生物干重,增加一级根数量,促进香蕉集中抽蕾,增大香蕉果指长、果指围,香蕉产量增加值达到29.37%;在滴灌施肥下有利于氮、钾等养分的平衡供应,提高养分的利用效率;滴灌施肥和喷水带灌溉加人工撒肥两种灌溉施肥方式均有利于节省肥料、人工等生产成本,而滴灌施肥条件下所取得的经济效益更显著。研究结果将为滴灌施肥技术在香蕉生产上的应用提供理论依据。 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