数控机床急停报警故障分析及处理

在数控机床正常运行过程中,若突然出现急停报警,则需要迅速关闭相关机床设备,对发生的急停报警故障进行研究和处理,排除其他安全隐患后,则可以恢复机床的工作。文章介绍了数控机床的急停报警系统控制原理,分析了数控率机床急停报警故障的诊断措施和排除具体故障的方式,以及故障分析的基本原则,供参考。     

数控机床的故障和日常维护

教育需要理论与实践相结合的教学，数控机床的教学更重视实践教学，数控机床的故障排除和数控机床的日常维护则成了实践中的一部分，机床的可靠性，直接影响实习的效果，本文主要从机床故障引起的主要原因出发，解决问题，做好机床的维护。     

浅谈数控机床的维护及故障处理

随着现代加工技术的迅速发展,数控机床的使用数量急剧上升,我国已成为世界数控机床使用第一大国。不同的数控机床虽然在结构组成上有所不同,但在机床系统维护、故障处理等方面有它们的共性。本文主要研究数控机床的系统维护要求及故障处理。     

数控机床的软硬件故障特征与维修合理性分析

数控机床是现代机械加工行业的主要设备,对于数控机床产生的故障问题,必须要做到及时合理的维修,才能确保机床尽快恢复良好的工作状态,以良好的效率完成机械加工的相关任务。对数控机床的技术现状和应用可靠性情况进行了介绍,说明了数控机床的软硬件故障的常见特征与故障处理方法,并对数控机床故障修复的合理性加以详细说明和分析,希望能提高数控机床故障的维修效果。     

CK6136型数控机床维修实例

数控机床是一种装有程序控制系统的机床,能够根据已编辑好的程序,控制机床的各动作部件,实现机床运转和产品加工的自动化控制过程,可以大大提高生产效率。此外,数控机床是集机械、电气、液压、气动等模块一体化的加工设备,因而其维修是一项复杂、技术性要求高的工作。笔者阐述了对数控机床维修者的能力要求,通过分析CK6136型数控机床的两个实例,详细介绍了故障发生与排除的全过程,仅供参考。案例证明,提升机床维修人员的综合素质有利于机床故障的尽早排除,最终提高机床的整体经济效益。     

数控机床常见故障及维修方法

数控机床作为一种数字控制机床,是将计算机和自动化技术融入机床设计中,是一种性能比较高且使用广泛的自动化机床,数控机床各部分之间联系紧密,故障涉及面广,因此,对数控机床的维修比对普通机床的维修提出了更高的要求。本文笔者根据实际工作经验谈一点数控机床故障分析和解决方法的心得体会。     

数控机床机械故障及防范

在机床生产过程当中,数控机床机械故障可以说是最为常见的故障之一。对于企业的正常生产而言,机床出现故障这是一种比较严重的影响,在当前比较常见的就是机床在运转的时候会发出噪声,或者是机械系统部件出现损毁等。在对数控机床机械故障维修的过程当中,难点在于故障的原因发现。文章对此进行分析及突出防范措施。     

如何利用参数检查法诊断数控机床故障

通过对数控机床产生参数故障原因的分析，结合实例介绍了如何运用参数检查法诊断数控机床的故障。     

对数控机床常见故障的诊断方法及维护探究

数控机床的种类多样,构造不同,降低故障出现的频率,减少维修时间,对提高机床的生产和工作效率十分重要。从这个意义上看,数控机床的故障诊断,也是一项十分重要的技术。在实际的工作中,必须要对数控机床常见的故障了如指掌,要能在第一时间诊断故障,并采取相应的维护措施。     

数控机床故障诊断与维修

数控机床是个复杂的系统,不可避免地会发生不同程度、不同类型的故障,导致数控机床不能正常工作。故障诊断是进行数控机床维修的第一步,它不仅可以迅速查明故障原因,排除故障,也可以起到预防故障发生与扩大的作用。文章结合数控机床中几个常见故障的维修实例,说明加强理论学习,适当了解数控系统硬件的相关连接及工作原理,注重系统保养,对于准确维修数控机床故障,降低机床故障率具有重要意义。     

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。