共查询到20条相似文献，搜索用时 250 毫秒
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近年来,天津市各级政府积极出台政策鼓励农民发展设施农业,设施农业发展迅速,已成为农村经济发展中极具潜力的经济增长点,显示了广阔的发展前景。与此同时,越来越多的卷帘机和通风设施应用到了各类温室大棚上。日光温室卷帘机和通风设施的广泛应用,大大降低了劳动强度,提高了工作效率,节约了生产成本,增加了大棚种植效益,进一步促进了设施农业的发展。一、天津市当前日光温室卷帘机和通风设施控制应用现状和问题温室大棚是现代农业的重要组成部分,随着日光温室卷帘机的广泛应用,对降低劳动强度,缩短劳动时间,延长光照时间,提高作物产量和品质方面发挥了重要作用。温室大棚的卷帘和通风是温室大棚生产必须环节,通风设施的机械化水平在一定程度上决定着温室大棚的发展水平,对促进温室大棚产出最大化具有很重要的现实意义。 相似文献
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ORP—80SA型双跨悬臂式卷帘机由天津市农机试验鉴定推广站开发研制,适用于长度为50m~80m、跨度为6m~8m日光温室草帘、保温被的卷铺。可在6min内一次性完成温室草帘、保温被的自动卷铺,大大降低了劳动强度,并可延长作物日采光时间2h,增加了作物光合作用时间,从而达到提高作物品质、产量和增加效益的目的。该卷帘机与普通蜗轮蜗杆卷帘机相比,具有结构紧凑、体积小、质量小、速比高、扭矩大的特点,在下雪结冰的恶劣环境下也可轻松卷铺。该机整机质量为60kg,配套电机为1.1kW~2.2kW,卷帘机转速为0.7r/min。ORP—80SA型双跨悬臂式卷帘机@杨德… 相似文献
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日光温室内的光照、温度、湿度、气体和土壤等环境条件影响温室内植物的生长发育,并与温室经济效益密切相关.根据植物生物学特性,利用卷帘机、节能热风炉、卷膜器、WQT-2型温室气体调质机、DFC-600型温室电除雾防病促生器和WSK-温室温湿度控制器等环境调控配套设备调控温室内的环境因子,以利于温室内植物的正常生长发育,提高日光温室内植物的产量和质量,增加温室的经济效益. 相似文献
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南疆地区昼夜温差大,蔬果资源欠缺,急需发展温室大棚等设施农业.目前,当地农户日光温室大棚取得了一定的经济效益,但仍存在生产效率低下,温室结构简单等缺点.文章针对温室大棚的控制问题及南疆地域特色并依据智能温室内部的光照、温度、湿度、土壤湿度等环境条件,设计了一种南疆低成本温室控制系统.采用反馈调节模式,使调节反应速度快、准确度高;结合番茄生长特点采用滴灌式水肥控制方案,能精确控制水肥供给与番茄根部水肥迁移规律.相比于传统日光温室,该温室具有建造综合成本低,操作性高,便于控制,资源利用率高等优势. 相似文献
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为进一步优化北京市密云区日光温室的结构，提高设施棚室的温度，以密云区现有的3种日光温室为基础，包括主动蓄热型日光温室（G1）、下沉型日光温室（G2）、当地传统的日光温室（G3），利用小气候综合观测仪的温度数据，对比分析了不同天气条件下3种日光温室生长季内的温度变化情况。结果表明：长周期条件下，G1、G2、G3的夜间平均气温分别为14.66、10.21和8.37 ℃；短周期条件下，G1、G2、G3的夜间平均气温分别为15.84、11.08和9.49 ℃；极端低温条件下，G1、G2、G3的夜间平均气温分别为10.63、7.54和6.24 ℃；典型晴天条件下，3座温室的夜间平均气温分别为17.83、11.48和9.16 ℃；典型阴天条件下，3座温室的夜间平均气温分别为9.64、7.03和6.04 ℃。G1型日光温室整体优于G2、G3型日光温室，在极端低温和典型阴天条件下都表现出了较好的保温储温性能，能够在较低温度下满足室内作物的生长要求。因此，主动蓄热型日光温室在北京市密云区具有较好的推广价值。 相似文献
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Overland water and salt flows in a set of rice paddies 总被引：1，自引：0，他引：1
E. Playn O. Prez-Coveta A. Martínez-Cob J. Herrero P. García-Navarro B. Latorre P. Brufau J. Garcs 《Agricultural Water Management》2008,95(6):645-658
Cultivation of paddy rice in semiarid areas of the world faces problems related to water scarcity. This paper aims at characterizing water use in a set of paddies located in the central Ebro basin of Spain using experimentation and computer simulation. A commercial field with six interconnected paddies, with a total area of 5.31 ha, was instrumented to measure discharge and water quality at the inflow and at the runoff outlet. The soil was classified as a Typic Calcixerept, and was characterized by a mild salinity (2.5 dS m−1) and an infiltration rate of 5.8 mm day−1. The evolution of flow depth at all paddies was recorded. Data from the 2002 rice-growing season was elaborated using a mass balance approach to estimate the infiltration rate and the evolution of discharge between paddies. Seasonal crop evapotranspiration, estimated with the surface renewal method, was 731 mm (5.1 mm day−1), very similar to that of other summer cereals grown in the area, like corn. The irrigation input was 1874 mm, deep percolation was 830 mm and surface runoff was 372 mm. Irrigation efficiency was estimated as 41%. The quality of surface runoff water was slightly degraded due to evapoconcentration and to the contact with the soil. During the period 2001–2003, the electrical conductivity of surface runoff water was 54% higher than that of irrigation water. However, the runoff water was suitable for irrigation. A mechanistic mass balance model of inter-paddy water flow permitted to conclude that improvements in irrigation efficiency cannot be easily obtained in the experimental conditions. Since deep percolation losses more than double surface runoff losses, a reduction in irrigation discharge would not have much room for efficiency improvement. Simulations also showed that rice irrigation performance was not negatively affected by the fluctuating inflow hydrograph. These hydrographs are typical of turnouts located at the tail end of tertiary irrigation ditches. In fact, these are the sites where rice has been historically cultivated in the study area, since local soils are often saline-sodic and can only grow paddy rice taking advantage of the low salinity of the irrigation water. The low infiltration rate characteristic of these saline-sodic soils (an experimental value of 3.2 mm day−1 was obtained) combined with a reduced irrigation discharge resulted in a simulated irrigation efficiency of 60%. Paddy rice irrigation efficiency can attain reasonable values in the local saline-sodic soils, where the infiltration rate is clearly smaller than the average daily rice evapotranspiration. 相似文献
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车用发动机润滑油失效规律与更换周期研究 总被引：7，自引：0，他引：7
研究在正常使用条件下１０Ｗ／３０－ＱＣ级润滑油用于某型车用发动机时所表现的失效规律,确认期服从两参数Ｗｅｉｂｕｌｌ分布,并给出分布的尺度参数η和形状参数ｍ之最佳线性无偏估计（ＢＬＵＥ）同时,还为定量分析,计算车用发动机润滑油的使用可靠性和合理确定其更换周期提供了一套可供借鉴的方法,并给出了具体的计算实例。 相似文献
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赵国杰 《农业机械化与电气化》2011,(4):106-107
乡（镇）农技推广体系是农业发展的关键。介绍朝阳市农业技术推广体系的现状,针对目前体制及运行机制、服务手段等方面存在的问题,提出适合朝阳市乡（镇）农技推广体系改革与发展的对策,以期对全省农技推广体系改革和发展起到一些借鉴作用。 相似文献
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苑庆刚 《农业机械化与电气化》2010,(3):52-54
草莓果味酸甜爽口,营养价值高,为人们所喜爱的应市鲜果之一。由于草莓易受损伤和微生物侵染,因此其采收、贮藏过程极为重要。介绍草莓采收过程中的注意事项以及11种贮藏保鲜技术的实施步骤和操作方法,推介9种加工方式,为草莓产业化提供技术支持。 相似文献
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对引进的谷子新品种金谷子耐旱TG118进行品种比较试验和多点试种。结果表明：该品种抗旱、耐瘠、适应性强,稳产、高产、抗病抗风抗倒伏强,品质优良,粮草兼用,种植简单,省工易管;一般产量在6000kg/hm2以上,比当地主栽品种增产20%以上。最高产量达9450kg/hm2,适于在辽西北地区推广应用。 相似文献
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对《种子法》存在问题的探讨 总被引：1，自引：0，他引：1
李鹏 《农业机械化与电气化》2011,(6):129-130
《种子法》是我国种植业第一部法律。自实施以来,为依法加强种子管理提供了有力的法律支撑,促进我国种子产业发生翻天覆地的变化。但随着依法管理工作的深入和种子产业的快速发展,《种子法》及配套规章的一些问题逐步显现出来。对《种子法》及配套规章存在的问题进行深入分析,对需要进一步补充的章节以及需要调整的内容进行深入探讨,以求更加完善和明确。 相似文献
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瓦房店市是我国重要的水果生产基地,在国内水果生产领域占有重要地位。随着水果市场化的不断深入,如何满足和适应国内外市场需求成为瓦房店市水果生产的关键问题。从瓦房店市水果生产实际出发,阐述了实施水果生产标准化的必要性,提出了发展水果生产标准化的具体措施。 相似文献
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在新世纪,面对机遇和挑战,党的十六大把“社会更加和谐”作为全面建设更高水平的小康社会的一个重要目标。中国人素有社会和谐的理想;西方人自古也向往社会和谐;借鉴东西方两种和谐社会思想的经验、教训,构建社会主义和谐社会理论。 相似文献
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About 30 years have passed since the Government of Egypt embarked on implementing a series of large scale drainage projects. At present, about 3.8 million acres have been provided with drainage systems on the basis of systematic pre-drainage investigations and designs. The target is to provide drains in approximately 6.4 million acres in the Nile Valley and Delta.The implementation of the subsurface drainage system is carried out by the public sector and private contractors under direct supervision of governmental regional departments. The implementation process depends on many factors related to the drainage material, machinery, manpower, site requirements, farmers and organizations involved. Problems and constraints are sometimes challenging, however, the annual rate of implementation has gradually increased to 170,000 acre/year.This paper discusses the different aspects involved in the implementation process of drainage systems. The development in materials, machinery and construction technologies will be reviewed. Institutional and management factors are going to be also considered. 相似文献