基于自动气象观测站的日光温室小气候特征分析   总被引：2，自引：0，他引：2  

朱敏  夏福华  杜池坡  孙翠芳  刘琴芳 《安徽农业科学》2008,36(31)

利用温室自动气象站自动观测资料和同期室外气象资料,对影响日光温室内的小气候环境因子进行了分析,结果表明:温室内的气温明显高于室外,温室日平均气温呈单波峰形变化;12月和翌年1月的相对湿度较高,应注意通风,避免温室蔬菜发生病虫害;1、2和3月的总辐射辐照度最高值均出现在12:00,而12月份的辐照度最高值出现在13:00;温室内0和5 cm浅层地温变化较大,5 cm地温变化小于地表温度变化;20和40 cm深层地温基本维持稳定,而且均高于上层地温,说明深层土壤有一定的蓄热作用。在不同的天气条件下,分析了温室内温度的变化规律,为合理调控温室内小气候环境因子,指导温室农作物生产提供了科学依据。  相似文献   

玉米冠层结构的自动调节与补偿机制研究   总被引：4，自引：2，他引：2  

张丽华  赵洪祥  谭国波  方向前  孟祥盟  闫伟平  边少锋 《玉米科学》2008,16(4):96-99

在玉米不同种植密度群体中初步研究了玉米群体的自动调节与补偿。结果表明,玉米群体在一定的密度范围内具有较强的自动调节能力。群体在叶面积上的自动调节能力较弱,而在干物质生产上的自动调节能力则较强。群体的自动调节作用对生殖器官的影响大于对营养器官的影响。产量因素的自动调节作用是生长后期的产量因素补偿生长前期损失的产量因素。  相似文献   

自动离合器起步模糊控制   总被引：2，自引：0，他引：2  

王旭东  谢先平  吴晓刚  余腾伟 《农业机械学报》2008,39(12):18-22

针对自动离合器起步控制问题,采用改进的发动机恒转速控制作为总体控制原则,提出了一种以节气门开度、发动机转速与目标转速的相对偏差及发动机转速变化率为主要控制量的离合器起步模糊控制策略,实现在满足冲击度条件下的发动机恒转速控制。样车试验结果表明,车辆在多种工况下均能顺利起步,起步平稳快捷,发动机转速波动小,起步冲击与起步意图相符。试验表明控制策略和算法具有良好的自适应性。  相似文献   

多组离合器参与的换挡过程混合建模与仿真     

张迎军  周志立  张明柱 《农业机械学报》2007,38(3):1-6

在分析多组离合器参与的自动变速器换挡过程特点的基础上,指出该换挡过程是由连续系统与离散系统组成的混合系统,进而提出基于键合图理论的连续系统和基于有限状态机的离散系统的换挡过程混合建模方法。在Matlab／Simulink和Matlab／Stateflow平台上建立了包含多种状态的东方红1302R型橡胶履带拖拉机液压机械无级变速器的换挡过程仿真模型,仿真结果表明该建模方法能很好地模拟自动变速器换挡过程中离合器的动态行为,并通过仿真分析了其对换挡品质的影响。  相似文献   

作物产量分类预报模型     

刘振忠  徐梅 《黑龙江八一农垦大学学报》1992,(1):53-58

本文把主成份分析方法应用在最优分割预报方法中,用主成份值作为最优分割方法中的分割因子,并在此基础上,建立了作物产量的最优分割预报模型。  相似文献   

奶牛呼吸频率自动监测技术研究进展     

《中国畜牧杂志》2019,(10)

在"互联网+现代畜牧业"和农业物联网普及应用的共同推动下,动物生命信息的获取与分析应用成为畜禽智慧养殖技术研究的热点。奶牛呼吸频率是反映养殖环境舒适度的重要特征,随着养殖业自动化与智能化的发展,呼吸频率自动监测的需求日益凸显。本文从接触式和非接触式两方面着重介绍了基于侧腹伸缩运动和呼吸气流变化的6种监测方法,分析了各类方法的优缺点、研究现状和应用前景,期望有助于完善奶牛生理参数自动监测装备的开发与生产应用,为国内开展奶牛智慧养殖研究提供参考。  相似文献   

日光温室管网化灌溉自动施肥系统的设计与应用     

李艳英 《中国蔬菜》1998,1(3):5-0

依据流体动力学原理，利用日光温室管网灌溉的静压能和文丘里管的特性，设计出在日光温室正常灌溉情况下的自动施肥系统。该系统设施简单，可操作性强，适于中等生产水平的日光温室蔬菜生产区应用。  相似文献   

三通道刨花干燥机刨花干燥过程自动控制系统初探     

王志同 《木材工业》1993,7(2):23-28,50

文中对三通道刨花干燥机刨花干燥中被控对象的特性、过程控制的方法、检测仪表、调节控制器与调速系统进行了探索与研究。干燥机的热效率高、刨花终含水率均匀、形态好。  相似文献   

新疆焉耆马血液生理指标的测定   总被引：1，自引：0，他引：1  

钟进芳  房少新  田风林 《畜牧与饲料科学》2009,30(6):24-25

运用美国雅培公司生产的CD1200型全自动血液分析仪,对21匹健康新疆焉耆马进行红细胞、白细胞、血小板等15项指标的测定.目前我国关于马血液指标的报道很少,对新疆焉耆地区的马血液指标未见有相关的报道,其测定结果可供兽医临床参考.  相似文献   

Allocation of feed based on individual dairy cow live weight changes: II: Effect on milk production     

Dorte Bossen  Martin Riis Weisbjerg   《Livestock Science》2009,126(1-3):273-285

Based on individual cow live weight gain, feeding strategies were designed for individual feeding of dairy cows in loose-housing systems, and examined in a four-year production trial including 115 Danish Red (DR), 91 Danish Holstein (DH), and 93 Danish Jersey (DJ). The objective of the present paper was to examine the milk yield obtained in response to three feeding strategies. The interrelationship between feed intake and live weight changes is presented in a companion paper.Cows were stalled in a loose-housing system based on automatic milking, automatic recording of feed intake and automatic weighing of the cows. All cows had 3 kg of individually separately offered concentrate (ISC) in addition to a mixed ration (MR). Cows were either allowed a medium energy MR during whole lactation (strategy MR1) or a high energy MR during early lactation, which was reduced to a low energy MR either early or late (strategy MR2-E and MR2-L). The early and late changes were defined as a live weight gain after live weight minimum at 15 and 35 kg, respectively, for DR/DH and 11 and 25 kg, respectively, for DJ. When MR energy concentration was changed, cows on the MR2 strategies were offered 3 kg per day of extra concentrate. The total allowance of 6 kg ISC was stepwise reduced to 3 kg per day as live weight continued to increase until 50 and 35 kg for DR/DH and DJ, respectively.Compared to feeding the MR1 strategy, the analysis showed that feeding the MR2 strategies did not significantly affect milk yield within primiparous DR and DH or within any DJ, as total lactation feed energy intake within these groups of cows was not significantly affected by the feeding strategy. Results obtained for multiparous DH showed that it is possible to increase milk yield without reducing the milk:feed ratio, when MR2 strategies were applied compared to the MR1 strategy. Feeding high energy rations during early lactation caused a higher peak feed energy intake within multiparous cows of DH and DR, but only multiparous DH obtained higher peak ECM yield in response to higher feed energy intake in early lactation. Across breed the results suggested that cows offered the MR2-E strategy might obtain higher lactation ECM yield compared to cows offered the MR2-L strategy due to a higher ECM yield persistency obtained by cows offered the MR2-E strategy. Results on feed intake and live weight changes presented in a companion paper indicated, that cows offered the MR2 strategies obtained a lower extent of mobilization compared to cows offered the MR1 strategy, and feeding the MR2-E strategy significantly increased duration of the mobilization period, which might have increased MR2-E cows' ability to maintain a high milk production during mid lactation.  相似文献