乙烯装置重要机泵以可靠性为中心的维修策略

介绍了乙烯装置重要机泵失效模式、影响及关键性分析(FMECA)结果,依据RCM分析方法所制定的维修策略及其对应的失效模式、失效原因、后果,说明乙烯装置中动设备的预防性维修主要针对四大压缩机组进行,对于有备台的泵机组而言基本可以执行状态检修乃至坏后修理的维修策略.     

基于可靠性的大型装备维修方式选择

以RCM(可靠性为中心的维修ReliabilityCenteredMaintenance)理论为基础,结合可靠性工程理论,综合考虑设备故障后果、系统可靠性因素来合理确定维修项目与维修方式,提出一种新的针对大型装备的维修方式选择的流程。并通过这一新流程,对原来维修大纲进行修改,建立新的维修大纲,从而指导大型装备维修活动,降低维修成本。     

以可靠性为中心的维修体系在大亚湾核电站的应用

本文简要阐述了以可靠性为中心的维修(RCM)理念、分析方法在大亚湾核电站的应用,描述了RCM分析成果指导现有状态监测和维修运行活动的程序,以及RCM分析成果在提高系统可靠性方面和降低系统及设备的运行和检修成本方面带来的变化,介绍了利用ENTEK状态监测软件分析设备故障及设备故障处理跟踪流程。     

当前工程机械维修存在的主要问题及解决方法

本文系统分析了当前工程机械维修的发展状况及存在的主要问题,结合研究现状,提出了改进对策及将RCM模式引入工程机械维修的建议.     

以可靠性为中心的维修

以可靠性为中心的维修是近40年发展起来的一种新的维修观念,它打破了传统的以定修为主的维修方式。随着RCM在国际上的推广和应用,其理论和方法的研究逐渐受到人们的重视,并且在实践应用中也取得了明显的经济效益。文中介绍了RCM的起源、思想实质与应用现状,并就RCM的下一步研究方向进行了讨论。     

有关“简化的”RCM的剖析

"以可靠性为中心的维修(RCM)"这-术语始见于1978年,指的是美国民航业所研究出的一种非常具体的决策制定方法.RCM在民航业中取得了令入瞩目的成就,主要表现为提高了安全性和可靠性,并增进了维修的费用效果.从20世纪80年代初开始,其他的许多行业也由于推行RCM而取得了同样的成果.在此期间,RCM方法本身也在两个基本方面有所演变.一是仍然忠实于原先在航空业中所采用的严格方法,只是增添了某些为充分表征1978年就已提出的关键设备性能所需的特性(诸如与环境的一体性和以量化方式表示的风险).目前,RCM的发展所达到的现代水平均具体体现在美国汽车工程师学会制订的标准SAE Standard JA1011中.二是寻找可减少实施RCM所需的时间和精力的根本途径(尽管运用真正的RCM时通常都要经过数月或至少数周之后方能取得回报).这种做法是试图通过略去RCM方法中的某些部分或者所研究系统中的某些部分,或者双管齐下地将RCM予以"简化".在本文中,作者从技术的严谨性、风险和产生的结果是否站得住脚等方面,对这种"走捷径的高招"表示了极大的怀疑.     

新的RCM评价准则

近30年来,由于社会对安全性的需求,RCM得到了迅速发展,但也出现了一些派生性的概念。为了准确定义RCM,最近,美国自动化工程协会与国防部联合制订了新的RCM标准,其中明确了RCM评价准则。文章主要介绍RCM最近的发展情况和新标准的产生过程,以及该标准中RCM的评价准则。最后,分析RCM发展的社会基础,并对我国RCM的发展进行简要介绍。     

RCM在舰载电子系统维修分析中的应用

为了提高装备预防维修的效率,应用RCM理论,分析了在预防维修中的一种策略,并以装备的可用性为目标,应用蒙特卡洛的方法,仿真确定出预防维修的时间间隔。     

应用可靠性为中心的维护(RCM)技术提升压缩机的运行管理水平

通过运用以可靠性为中心的维护技术(RCM)对大港油田天然气公司天然气处理站的压缩机进行了风险分析,确定了压缩机的重要功能件,分析了各个功能件的风险等级,有针对性地制定了压缩机的维护策略。对于经常出现故障的高风险功能件实施技术改造,有效地降低了压缩机运行中的风险,提高了压缩机的安全性和可靠性,从而提升了压缩机的运行管理水平。     

基于RCM的曲轴维修周期研究

针对国内船舶设备中事后维修造成的维修不足和定期维修造成的维修过剩现象,从可靠性理论推导出视情维修的数学模型,并结合目前的曲轴检测状况,提出在可靠性数据允许条件下,定量地决策出最佳维修时期。     

Low-dose aberration corrected cryo-electron microscopy of organic specimens

Spherical aberration (C(s)) correction in the transmission electron microscope has enabled sub-angstrom resolution imaging of inorganic materials. To achieve similar resolution for radiation-sensitive organic materials requires the microscope to be operated under hybrid conditions: low electron dose illumination of the specimen at liquid nitrogen temperature and low defocus values. Initial images from standard inorganic and organic test specimens have indicated that under these conditions C(s)-correction can provide a significant improvement in resolution (to less than 0.16nm) for direct imaging of organic samples.     

汽轮机转子部件工作能力的保障服务方法研究

针对汽轮机转子部件工作能力的保障服务问题,在考虑产品全生命周期的条件下提出了使用面向可靠性的维护（RCM）理论、基于知识的推理及基于SOA的网络计算技术等的工业产品主动预防性维护平台iTurbPSS的实现思想和主要使能技术,并据此进一步阐述了基于故障诊断和Agent的分级维护服务流网络结构的建模方法以及考虑用户需求的协同维护服务决策机制,以解决工业装备类产品的功能保障服务问题。     

装备日常维护精细化管理流程设计

采用现代技术的装备,其故障规律用传统的浴盆曲线解释已不太全面,仅靠事后与定期维修已不能保证装备的正常运行。通过将PDCA循环、RCM、点检方法、6S与6H方法、FRACAS方法,集成为装备日常维护的精细化流程管理方法,并用此方法设计出一套装备维护及故障管理的流程,从而确保装备的正常使用,提高故障预测与管理能力。     

Extraglandular and intraglandular vascularization of canine prostate

The literature on the vascularization of the canine prostate is reviewed and the clinical significance of prostate morphology is described. Scanning Electron Microscopy (SEM), combined with improved corrosion casting methods, reveal new morphological details that promise better diagnostics and treatment but also require expansion of clinical nomenclature. A proposal is made for including two previously unnamed veins in Nomina Anatomica Veterinaria (NAV). The canine prostate has two lobes with independent vascularization. Each lobe is supplied through the left and right a. prostatica, respectively. The a. prostatica sprouts three small vessels (cranial, middle, and caudal) towards the prostate gland. A. prostatica is a small-size artery whose wall structure is similar to the arteries of the muscular type. V. prostatica is a small-size valved vein. The canine prostate has capsular, parenchymal, and urethral vascular zones. The surface vessels of the capsule are predominantly veins and the diameter of arterial vessels is larger than that of the veins. The trabecular vessels are of two types: direct and branched. The prostate parenchyma is supplied by branches of the trabecular vessels. The periacinary capillaries are fenestrated and form a net in a circular pattern. The processes of the myoepithelial cells embrace both the acins and the periacinar capillaries. In the prostate ductal system. there are spermatozoa. The prostatic part of the urethra is supplied by an independent branch of a. prostatica. The prostatic urethral part is drained by v. prostatica, the vein of the urethral bulb and the ventral prostate veins. M. urethralis begins as early as the urethral prostatic part. The greater part of the white muscle fibers in m. urethralis suggest an enhanced anaerobic metabolism.     

Comparative study of a block copolymer morphology by transmission electron microscopy and scanning force microscopy

Using transmission electron microscopy (TEM) and scanning force microscopy (SFM) together, it was possible to verify important structural features of a nanostructured bulk material such as the kp‐morphology in an ABC triblock copolymer. By applying suitable imaging techniques during the SFM measurements it was possible to determine the morphology without additional manipulation steps in between. In comparison, TEM investigations on this type of material usually require selective staining procedures prior to the measurement. Also electron beam damage is often encountered during TEM measurements especially if components such as poly(methacrylates) are present. In contrast, SFM measurements can be assumed not to significantly change the phase dimensions of the components.     

A simple method for correlative light,scanning electron microscopic and X-ray microanalytical examination of the same section

Thin paraffin sections, mounted on scanning specimen holders previously coated with polyester film tape (Minnesota Mining and MFG Co., Scotch film tape No. 850 gold), were processed for light microscopy (LM) in the conventional way, then covered with celloxin shellac and examined in the LM by using the upper illuminating source. After removal of the shellac from the surface of the sample by immersion in acetone, the sections were air-dried, coated with a copper layer in a vacuum evaporator and examined in a scanning electron microscope (SEM). The method allows: (i) high-quality LM possibilities for establishment of the diagnosis in pathological cases; (ii) SEM examination of the same area as observed in LM; and (iii) EPMA measurements of insoluble precipitates embedded in the tissue. The usefulness of the proposed method is obvious in cases where the composition of a precipitate on LM scale is to be compared with the LM appearance of the surrounding tissue.     

Transmission electron microscopy staining methods for the cortex of human hair: a modified osmium method and comparison with other stains

For wool, superior staining of a wide range of ultrastructural components is achieved by en bloc treatment of fibres with a chemical reductant followed by osmium tetroxide. For human scalp hair, although staining quality is similar, the penetration of reagents is poor, resulting in large parts of the fibre cortex remaining unstained. Here we describe a modification to the reduction-osmication method in which reagents penetrate through a cut fibre end, allowing visualization of a wide range of features across the cortex. We compare the staining quality, artefacts and range of structure rendered visible using transmission electron microscopy for en bloc reduction-osmication to other staining alternatives including en bloc silver nitrate and section stains based on uranyl acetate and lead citrate, phosphotungstic acid, potassium permanganate, ammoniacal silver nitrate and some combinations of these stains. The effects of hair-care treatments are briefly examined.