拖拉机可靠性试验及考核中遇到的问题

当前我国拖拉机进行可靠性试验采用的方法是定时截尾试验，即样机试验到规定的试验时间就截止，对试验的数据进行分析处理获得拖拉机可靠性考核指标的方法。当前各个拖拉机生产企业和农机试验鉴定部门主要是依据行业标准JB／T51082—2000（（拖拉机产品可靠性考核》和国家推荐性标准GB／T24648．1-2009《拖拉机可靠性考核》对拖拉机的可靠性进行试验与考核，但依据该标准对拖拉机进行可靠性试验及考核时却存在一些问题。     

卷盘喷灌机水涡轮性能测试系统数据校正

为保证卷盘喷灌机水涡轮性能测试数据的真实可靠,需要对卷盘喷灌机水涡轮性能测试系统进行数据校正。为此,通过建立卷盘喷灌机水涡轮性能参数采集数据的数学模型,推导出水涡轮参数采集数据与实际数据的函数关系,得到参数测量误差与实际信号的对应关系;在保证性能测试系统试验条件与试验环境相对稳定的条件下,计算出各性能参数的校正参数,并基于Lab View开发平台对卷盘喷灌机水涡轮性能测试系统数据校正进行软件设计。通过误差分析表明:本研究对卷盘喷灌机水涡轮性能测试系统的数据校正符合GB/T3216-2 0 0 5《回转动力泵水力性能验收试验1级和2级》的规定,可以有效提高卷盘喷灌机水涡轮性能测试系统测试数据的准确性。     

新标准实施后混凝土搅拌机搅拌性能试验方法分析与研究

文章主要对混凝土搅拌机标准GB/T 9142-2000与GB/T 9142-2021进行分析,重点研究在新标准下混凝土搅拌机搅拌性能的试验过程,分析新标准实施后搅拌机搅拌性能的试验优势和劣势,为混凝土搅拌机均匀性试验提供借鉴。     

水泵微机测试系统的误差分析与评定

对水泵微机测试系统测试参数流量Q、扬程H、输入功率P、转速n、效率的系统误差和随机误差的计算公式进行了分析和介绍,阐述了误差产生的原因,同时以1600QZ-100C和1400QZ-100泵为例进行试验.通过误差计算和分析表明:江苏大学新开发的水泵微机测试系统各项误差符合GB/T 3216《回转动力泵水力性能验收试验1级和2级》,GB/T 12785《潜水电泵试验方法》的2级规定.     

大豆粗脂肪酸值测定结果不确定度的评定

按照GB/T14488.1-2008《植物油料含油量测定》和GB/T5530-2005《动植物油脂酸值和酸度的测定》,对大豆粗脂肪酸值进行测定,对测试结果的不确定度进行评定,量化了影响测定结果的不确定度分量。结果表明:当大豆粗脂肪酸值为1.1(KOH)/(mg/g)时,扩展不确定度为0.032(KOH)/(mg/g)(K=2)。     

两种国标方法测定油脂过氧化值的比较与方法改进

通过采用两种国标方法测定油脂中过氧化值含量,经对比分析发现,GB/T5009.37-2003法准确度和精密度良好,加标回收率96.06%～106.24%,相对标准偏差小于1.0%;GB/T5538-2005法易受油脂颜色和样液浑浊乳化的干扰,滴定终点难判断,测定结果重现性差,相对标准偏差大于5.0%,结果可信度差。为此对GB/T5538法进行了改进,改进后的方法加标回收率88.46%～108.31%,相对标准偏差小于3.0%,且与GB/T5009.37法测定结果无显著差异,既可满足实验室日常检测油脂过氧化值工作需求,又可减少对操作者和环境的危害。     

基于Excel的水泵性能试验数据处理的VBA开发

水泵性能曲线试验数据在用Excel表格进行存储时,为了使水泵性能数据在Excel通用电子表中能自动进行数值计算,利用VBA对原先编制的Excel水泵性能试验数据处理表进行了二次开发.在电子表中增加了水泵试验容差等级选择和试验结果按钮,根据GB/T 3216—2005标准规定的容错等级和判别准则以及最小二乘拟合算法和插值计算算法,分别对这两个功能按钮进行了VBA编程,通过点击试验结果按钮,就可实现水泵性能试验数据的插值计算和性能判别,得到了水泵规定点和交点的性能数据及判别结果.以BQW15-30-4型潜水泵为应用实例,进行水力性能试验,并进行了性能判别及绘制性能曲线.结果表明,H-Q曲线刚好与容差十字线垂直线段下端相交,满足要求.该方法增强了Excel处理水泵试验数据的插值计算功能,省略大量曲线绘制工作.     

基于ABAQUS的拖拉机防翻架有限元仿真分析

为预测拖拉机防翻架安全性能的试验认证,通过查阅文献获得材料塑性阶段的数据,依据GB/T 19498-2004规定的试验方法,应用ABAQUS软件对防翻架模型进行了静态试验仿真分析,通过不同方案的对比分析,优化了结构设计,为拖拉机防翻架的设计和改进提供了理论依据。     

柴油机功率与燃油消耗率修正方法的探讨

柴油机的有效功率和燃油消耗率随着环境状况(大气压力、相对湿度和环境温度)的变化而变化,环境状况的改变对柴油机的测试结果有着直接的影响.GB/T1105-87对此有明确的规定,如果测试柴油机的环境状况与标准环境状况不符时,则必须对测试结果进行必要的修正.为此,根据多年的实际试验经验对修正方法进行必要的补充,以供共同探讨.     

一种添加纳米金刚石悬浮液汽车经济性试验研究

润滑油添加剂有助于保护金属表面,提高发动机的抗磨性,也可以提升发动机动力性。本文研究一种基于纳米级金刚石悬浮液添加条件下的发动机性能测试,参考发动机动力性、经济性以及排放指标的变化进行技术分析。通过AVL底盘测功机以及尾气分析仪分析车辆添加悬浮液技术数据变化,提供应用结论。目前国内没有针对不同添加剂性能测试试验分析标准,针对目前汽车后市场车用添加剂的选择,依据中华人民共和国国家标准GB/T12545.1-2008--汽车燃料消耗量试验方法搭建测试平台,为同类产品应用提供可执行测试方案,综合分析汽车运行性能。     

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。