货车车轮踏面擦伤分析与防范

文章通过对轮对踏面擦伤的成因分析,如制动造成的问题、轮对质量问题及调车作业问题的详细阐述,提出了全面防范货车车轮踏面擦伤的一些思路及方法。     

货车车轮踏面擦伤分析与防范

文章通过对轮对踏面擦伤的成因分析,如制动造成的问题、轮对质量问题及调车作业问题的详细阐述,提出了全面防范货车车轮踏面擦伤的一些思路及方法。     

制动异常及其产生的原因

机动车在行驶中进行制动 ,常常因为制动系统的技术状况不良而出现一些异常现象 ,达不到预期的制动效果 ,因而可能酿成事故。现将几种常见的制动异常现象及主要原因叙述如下 :一、制动跑偏机车制动时自动偏向一方 ,驾驶员无法控制制动过程中机车前进的方向 ,称之为制动跑偏。一般有以下三种情况 :1.有规律的定向跑偏机车在制动时出现有规律的定向跑偏 ,其原因有 :(1)制动机构本身的原因 :①左右车轮的制动片与制动鼓间隙不一样 ;②个别车轮制动摩擦片有油污、泥水、硬化点或铆钉外露 ,使摩擦系数降低 ,造成制动跑偏 ;③左右车轮制动摩擦片材…     

拖拉机行驶途中突发险情的应急处理

1机车驶出路肩悬空机车行驶中一旦有车轮驶出路肩而悬空停住车时，驾驶员应选择既安全又不使机车失去平衡的地方离开驾驶室，然后仔细观察机车的险增，并根据情况采取相应的措施。2行驶中飞车在行驶中突然飞车，应迅速关闭油门。若不能熄火，应扳动减压拉杆；使发动机减压；无减压拉杆的，这时应猛踏制动器踏板，以增加发动机的负荷（这时应控制好拖拉机方向），使发动机憋熄火。但切不可用下离合器踏板停车，否则发动机的转速会急剧升高。3＄＃f＆若行驶中轮胎突然爆裂，机车立刻会向破胎一侧跑偏，此时应全力控制好拖拉机的行驶方向，迅速…     

拖拉机行驶途中突发险情的应急处理

(1)机车驶出路面悬空.机车行驶中一旦有车轮驶出路面而悬空时,驾驶员应选择既安全又不使机车失去平衡的地方离开驾驶室,然后仔细观察机车的险情,并根据情况采取相应的措施.     

机车车轮在不同工况下的静力分析

有限元仿真技术在机械制造业中变得越来越重要,在对机械零部件的刚度、强度、热力学、疲劳等的分析中具有提供先验经验及数据的作用,避免了复杂及高成本的实验,使得工业生产实现了高效率和高安全性。轨道交通现在已经变成了我国最重要的交通方式。近些年轨道交通向着高速及重载化方向发展,随之而来的运行安全问题也变得日益突出。车轮作为机车重力的支撑部以及牵引和制动的执行部,其安全性的研究受到许多关注。文章以机车车轮为研究对象,分析其在不同工况下的应力分布。     

拖拉机行驶途中突发险情的应急处理

1．机车驶出路肩而悬空 机车行驶中一旧有车轮驶出路肩而悬空时，驾驶员应选择既安全又不使机车失去平衡的地方离开驾驶室，然后仔细观察机车的险情，并根据情况采取相应的措施。     

拖拉机行驶途中突发险情的应急处理

1.机车驶出路肩悬空机车行驶中一且有车轮驶出路肩而悬空停住车时,驾驶员应选择既安全又不使机车失去平衡的地方离开驾驶室,然后仔细观察机车的险情,并根据情况采取相应的措施。2.行驶中飞车在行驶中突然飞车,应迅速关闭油门。若不能熄火,应扳动减压拉杆,使发动机减压;无减压拉     

拖拉机行驶途中突发险情的应急处理

1.机车驶出路肩而悬空机车行驶中一旦有车轮驶出路肩而悬空时,驾驶员应选择既安全又不使机车失去平衡的地方离开驾驶室,然后仔细观察机车的险情,并根据情况采取相应的措施。2.行驶中飞车在行驶中突然飞车,应迅速关闭油门。若不能熄火,应扳动减压拉杆,使发动机减压;无减压拉杆的     

拖车轴承也要保养

拖车是拖拉机主要运输工具,在使用中拖车车轮经常发生晃动,轮轴弯曲,轴承早期磨损或损坏.造成轴承、轮胎等部件提前损坏,重者车轮飞出或断轴,危及人身和机车安全.     

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.     

车用发动机润滑油失效规律与更换周期研究

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。     

农村剩余劳动力就业问题的探讨

论述了我国农村剩余劳动力就业的意义，并针对我国农村剩余劳动力的现状，提出多渠道促进农村剩余劳动力就业的途径和办法。     

乡（镇）农业技术推广体系存在的问题及对策

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。     

草莓的采收与贮藏

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。     

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。     

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。     

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.