共查询到20条相似文献,搜索用时 421 毫秒
1.
略谈我国的卷管式绞盘喷灌机的开发和应用 总被引:7,自引:3,他引:4
目前,欧洲各国生产卷管式绞盘喷灌机的厂商有10多家,生产产品不仅规格品种多,而且技术先进。这种喷灌机在我国也具有广阔的发展前景,于是如何开发新品种,尽快形成系列产品,进一步提高国产喷头的可靠性,将是我国卷管式绞盘喷灌机开发应用的主攻方向。 相似文献
2.
85.什么是机组式喷灌系统?
答机组式喷灌系统也称自走式喷灌机,是将喷灌系统中有关部件组装成一体,组成可移动的机组进行作业。其优点是结构紧凑、机动灵活、机械利用率高,能够一机多用,单位喷灌面积的投资低。机组式喷灌系统,分为时针式喷灌机、平移式喷灌系机和卷管式喷灌机(又称绞盘式喷灌机)。机组式喷灌系统又可分为轻小型机组式喷灌系统、大中型机组式喷灌系统。 相似文献
3.
刘琦宫玉敏邵泽亮陈金利张义胜 《农业装备与车辆工程》2019,(S1):170-172
电驱动绞盘式喷灌机被广泛应用于大田灌溉作业,由于电机驱动特性,作业时随着软管层数增多收管速度逐渐增大,导致喷灌作业不均匀。在固定的收管速度下,通过计算得出每层软管对应的收管频率。在喷灌机上寻找参照点,设计机构改变电机频率,保证作业全程线速度保持一致,实现全程匀速收管并自动断电,大大提高电驱动绞盘式喷灌机的应用性。 相似文献
4.
近几年来,我国喷灌机具的研制工作又有了新的发展,先后鉴定投产了一些质量较好和技术指标较先进的喷灌机具新品种,如Py_1低压小喷头,金属移动管道,垂直摇臂式喷头,电动圆形喷灌机、绞盘卷管式喷灌机,内、外混式自吸泵和水环式自吸泵等。这些为我国喷灌事业向深度和广度发展奠定了一些基 相似文献
5.
1我国喷灌设备发展的现状1.1研制设备的种类1.1.1喷灌机(组)我国的喷灌机从研制的情况来看,大、中、小、轻型喷灌机都研制过。大型喷灌机我国先后研制的型式有观意壁式、拖拉机单喷头悬挂式、中心支轴式、平移式、滚移式和技盘卷管式等。据农垦系统1990年统计,已有大型喷灌机1100台,喷灌面积11万hm2。目前定型批量生产和使用较多的是电动中心支轴式和滚移式喷灌机。中型喷灌机我国曾研制过单喷头悬挂式、双悬臂式、绞盘卷管式和移动管道机组式等型式.除移动管道式机组外,其它推广应用不多,未形成批量规模。最近经盘卷管式生产和… 相似文献
6.
7.
1 引进概况 卷管式绞盘喷灌机是70年代初期在移管式喷灌系统基础上发展起来的具有结构紧凑、移动方便、操作人员少、能自动行走进行喷灌作业的新颖机具. 相似文献
8.
随着节水灌溉技术在我国的推广应用,我国的节水灌溉设备也得到了相应的发展。本方就我国的喷灌和微灌设备的现状、存在问题和今后发展方向谈谈个人的粗浅看法。1我国喷灌设备发展的现状1.1喷灌机(组)我国的喷灌机从研制的情况来看,大、中、小、轻型喷机都研制过。大型喷灌机我国先后研制的型式有双悬壁式、拖拉机单喷头悬挂式、中心支轴式、平移式、滚移式和绞盘卷管式等。据农垦系统1990年统计,已有大型喷灌机llto台,喷灌面积11万hm2。目前定型批量生产和使用较多的是电动中心支轴式和滚移式喷灌机。中型喷灌机我国曾研制过单喷头悬… 相似文献
9.
10.
圆形喷灌机泵注式施肥装置设计与田间试验 总被引:4,自引:0,他引:4
圆形喷灌机水肥一体化作业时对喷洒肥液均匀性有较高要求,需要采用比例施肥装置,确保注入喷灌机的肥液流量保持恒定。为此设计了基于柱塞式注肥泵的泵注式施肥装置,并以注射喷嘴的孔口直径、安装位置以及注肥泵的电源频率为变量,进行了圆形喷灌机应用泵注式施肥装置的喷灌施肥均匀性试验。结果表明,圆形喷灌机停止状态下,注肥泵电源频率50 Hz运行时,3种注射喷嘴孔口直径和3种安装位置的组合工况下喷灌施肥的均匀系数CU为99.00%~99.65%,变异系数CV为0.46%~1.37%,其中当注射喷嘴孔口直径为2.5 mm、安装在进水管水平段位置的工况时获得的喷灌施肥均匀性最佳。圆形喷灌机行走状态下,测得单列雨量筒喷灌施肥均匀系数C*UH为88.77%~90.66%,表明圆形喷灌机采用泵注式施肥装置能够获得较高的喷灌施肥均匀性。此外,通过对比注肥泵电源频率在50 Hz和46 Hz时的喷灌施肥均匀性,发现喷头喷洒肥液的电导率总平均值与电源频率之间具有显著的正相关性,表明改变注肥泵的电源频率是圆形喷灌机实现高均匀度变量喷灌施肥的一种有效途径。 相似文献
11.
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
12.
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
13.
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
14.
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
15.
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
16.
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
17.
在介绍粉质仪和拉伸仪结构和原理的基础上,探讨了粉质曲线中吸水率、形成时间、稳定时间、弱化度和评价值等指标与面粉品质的关系,以及如何根据拉伸曲线中面团最大拉伸阻力、延伸度和拉伸曲线面积等指标来评价面团品质,并结合生产实际,概述了粉质仪和拉伸仪在面粉生产中的作用。 相似文献
18.
19.
车辆ABS控制算法的研究及探讨 总被引:1,自引:0,他引:1
对现代汽车的ABS控制算法作了一些简单的介绍,同时指出了它们的一些缺陷,相应地提出了几种对ABS的其它控制方法并加以探讨,其中着重论述了ABS门限值控制算法中参考车速的确定方法和基于附着系数的控制算法。 相似文献
20.
工厂化养殖是现代水产养殖的必然发展趋势,需要重点解决的问题是连续不间断地监测并控制养殖水质.为此.提出了一个远程在线自动测控系统方案,实现并成功应用于水产养殖基地.经实践证明,此系统是一个结构简单、低投入高产出、实用价值较高的工厂化水产养殖远程自动测控系统. 相似文献