剪羊毛机剪头振动参数测试方法的研究

提供了一种与英国、原苏联及我国现行标准不同的剪羊毛机剪头振动参数测试的新方法，实现了直接测取其激励。优点是所测数据可重复、可比，真实反映了剪头扭振的实质，还可测定关节齿轮及软轴对剪头振动的影响，且安装操作方便。     

剪羊毛机加压机构的分析研究

分析研究了直动式剪羊毛机的加压机构及加压杆长度对加压力的影响；同时介绍了一种压力传感器。用此传感器可以测出加压杆上的加压力，检查机体的垂直度，从而为提高剪羊毛机的制造质量提供科学依据。     

新颖的软轴式剪羊毛机打进国际市场

<正>新疆牧业机械厂承担的国家级重点新产品试制任务——95MR76.2A型软轴式剪羊毛机,在吸取了国外剪羊毛机技术及国内剪羊毛机的生产和使用经验后,经过三年多的努力,研制出了结构紧凑,剪毛顺畅,手握舒适,温升低,噪声小,机件耐磨损,易拆     

直齿型与弯齿型剪羊毛机定刀片

剪羊毛机的剪切装置是由动刀片及流状定刀片组成。定刀片是剪羊毛机直接剪切羊毛的主要零件．安装在机体前端．当剪毛机剪切羊毛向前推进时．梳状定刀片的流齿就插入羊毛中．起着流理羊毛和支承剪切的作用。动刀片在定刀片上以很高的速度做弧形往复运动，依靠动、定刀片的刃口将羊毛剪切下来。定、动刀片的结构和重量将对剪羊毛作业产生直接影响。剪羊毛机定刀片．原国内生产只有一种形式即直齿型，如图1所示。两边齿间的宽度为76．Zmrn，我厂自1967年建厂至1992年一直生产这种直齿型走刀片。90年代初，为提高刀片质量和参与国内外币场竞争…     

直齿型与弯齿型剪羊毛机定刀片的比较

剪羊毛机的剪切装置是由动刀片及梳状定刀片组成,如图1所示。定刀片是剪羊毛机直接剪切羊毛的主要零件,安装在机体前端,当剪毛机剪切羊毛向前推进时,梳状定刀片的梳齿就插入羊毛中,起着梳理羊毛和支撑剪切的作用。动刀片在定刀片上以很高的速度做弧形往复运动,依靠动、定刀片的刃口将羊毛剪切下来。那么,定、动刀片的结构和质量将对剪羊毛作业产生直接影响。     

用应变式扭转传感器测转动惯量

利用应变式扭转传感器，根据转惯量的可加性，通过用共振法测一阶固有频率的方法，测取扭转传感器自身的转动惯一和抗扭刚度系数以及剪羊毛机各零部件的转动惯理。结果证明这种方法是有效的，且有足够的精度。     

滚动冲击压实机械水平振动控制研究

在对滚动冲击压实机理、动态特性及减振机构研究的基础上，建立滚轮、机架、牵引主机及驾驶员的等效振动系统的力学模型，对不同工况滚轮水平振动对牵引主机及驾驶人员的影响进行分析测试，提出削减机架及牵引主机水平振动，改进驾驶员乘坐振动舒适性的控制方法。     

单相串激式电动剪羊毛机电动机的检修

单相串激电动机转速高、单位体积功率大、起动转矩高,是便携式手持工具的理想动力。为此,分析了单相串激式剪羊毛机电机的常见故障及检修方法。其中,对转子进行绝缘处理的环氧树脂胶的配比和操作工艺,是笔者多年实践的经验总结,对单相串激式剪羊毛机电机修理具有实际参考价值。     

浅析低频共振夹持与果实采摘——以桑葚采摘为例

随着农业技术的发展,桑葚的种植面积大量增加,依靠人工采摘桑葚不仅效率较低而且质量难以保证,而低频振动采摘桑葚不仅保证了高效率,还保障了果实品质。鉴于此,本研究概述了夹持头选择,设计了收获机振动夹持头,对桑葚枝条不同位置进行了振动脱落试验。结果表明：铝合金和镁铝钛合金最适合用于制作夹持头,枝干振动频率在6.11 Hz的时候,选择二级枝干上部或二级枝干中部采摘效率最高,对树木产生的伤害也较小,果实掉落半径较小容易收集;果实采摘根据不同枝干的半径,应用不同的夹持力夹持枝干,同时要注意果实掉落高度最好在0.4 m以内,可减轻果实损伤程度。     

切头飞剪动态特性研究

针对剪刃为圆弧形的特点,对剪刃进行了微分处理。并利用弱塑性变形理论推导出了弧形剪刃的剪切力公式,同时采用曲线拟合的方法求出十几种钢在不同温度下,剪应力相对切入深度的数值关系,用以计算在不同板厚、钢种、切入深度和温度条件下的剪切力,进而得出剪切力的变化脉动图。还对切头飞剪在剪切过程中的动能及启动、制动过程中的惯性力进行了定性的分析,绘出了力能参数脉动图。     

Overland water and salt flows in a set of rice paddies

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.     

瓦房店市水果生产标准化发展研究

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。     

金谷子耐旱TG118引种试种及推广应用

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。     

对《种子法》存在问题的探讨

《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。     

Review of the Egyptian experience in implementing land drainage projects

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.     

和谐社会理论建设的几点哲学思考

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。     

A European irrigation map for spatially distributed agricultural modelling

We present a pan-European irrigation map based on regional European statistics, a European land use map and a global irrigation map. The map provides spatial information on the distribution of irrigated areas per crop type which allows determining irrigated areas at the level of spatial modelling units. The map is a requirement for a European scale assessment of the impacts of irrigated agriculture on water resources based on spatially distributed modelling of crop growth and water balance. The irrigation map was compiled in a two step procedure. First, irrigated areas were distributed to potentially irrigated crops at a regional level (European statistical regions NUTS3), combining Farm Structure Survey (FSS) data on irrigated area, crop-specific irrigated area for crops whenever available, and total crop area. Second, crop-specific irrigated area was distributed within each statistical region based on the crop distribution given in our land use map. A global map of irrigated areas with a 5′ resolution was used to further constrain the distribution within each NUTS3 based on the density of irrigated areas. The constrained distribution of irrigated areas as taken from statistics to a high resolution dataset enables us to estimate irrigated areas for various spatial entities, including administrative, natural and artificial units, providing a reasonable input scenario for large-scale distributed modelling applications. The dataset bridges a gap between global datasets and detailed regional data on the distribution of irrigated areas and provides information for various assessments and modelling applications.     

粉质仪和拉伸仪在面粉生产中的应用

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。     

农村信息化服务的现状及建设措施

分析当前我国农村信息化服务的现状,提出加强农村信息化服务的新举措。     

车辆ABS控制算法的研究及探讨

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。