阳极炉圆盘浇铸机中心回转支撑检修的流程优化

以往对圆盘浇铸机中心回转支撑实施常规检修,需要在拆卸圆盘辐射梁、横梁及中心筒的情况下进行,检修耗时长,劳动强度大,生活效率低。通过制作专用工装,采用一步到位更换圆盘浇铸机中心回转支撑的整体拆装检修方案及配套措施,不仅可以大幅缩短检修时间,而且可以降低检修劳动强度和节省检修费用,具有较大的行业推广应用价值。     

强制循环蒸发器中混流泵的应用与维护

通过对强制循环泵结构研究,针对拆卸叶轮困难,安全隐患大,进出口管道割除焊接难度大,时间长等影响混流泵检修工期的现状。找到检修过程的难点并对检修过程进行分析,找到将叶轮首先固定,再拆装轴承体总成,彻底改变混流泵检修的次序从而优化整个检修过程的全新检修模式,极大的减少检修步骤,减轻检修工作量,缩短检修工期。     

桥式起重机卷扬筒装配结构改进

卷扬筒是起重机起升机构的重要部件。在日常的检修中,如更换起升机构中的易损件,势必涉及到卷扬筒的拆装,由于目前桥式起重机卷扬简装配结构设计的特点,使卷扬筒的安装和拆卸十分困难,我厂起重机检修工人在长期的经验积累中发现,只要在安装结构上稍加改进,增设一个轴承挡圈,便会使卷扬筒的拆装变得十分简便,拆装时间可从原来4小时缩短到1时左右。     

大型回转类设备现场修复介绍

激光修复是目前国内一种新型的表面处理技术,但基本上都需要将待修复设备拆卸运输至专业厂家进行修复。介绍了关于大型轴颈类设备由于运输困难、拆装工期长严重影响生产的情况下,提出并解决了现场激光修复的应对措施,在国内大型设备现场修复尚属首次,对大型轴颈类现场修复具有很好的参考价值。     

隔膜室盖螺母液压拆装工具在隔膜泵中的应用

越来越多的用户需要高压大流量的隔膜泵,隔膜泵结构中的承压件大多是螺栓连接,螺栓的拧紧和拆卸已成为一个重要的问题.我公司也曾经出现过螺栓断裂造成设备停机,影响生产的情况,所以我们分析了原因,借鉴外国的先进技术.研制了隔膜室盖螺母液压拆装工具.本文介绍了螺栓的预紧力,拉伸的胡克定律和隔膜室盖螺母液压拆装工具的结构原理,及使用方法.     

矿用铰接式卡车运输安全管理对策研究

随着城门山铜矿二期工程的扩建和采剥比的逐年攀升,凹陷开采加剧,矿用铰卡汽车安全事故频发且呈复杂多样化,安全形势异常严峻,面对设备劣化倾向的加剧、原材料成本涨价及成本压缩等窘境,该矿针对历年来铰卡安全管理中存在的问题,进行了技术管理创新及对策研究,其具有一定的推广应用价值。     

宝钢2050热轧粗轧机主轴的拆装工艺研究与实施

对宝钢2050热轧厂R主轴采用新工艺方法进行了拆卸与组配,并对拆卸、装配要点进行了阐述及总结.这种主轴采用轴体与叉头为小过盈量加黏结剂的装配形式,装配工艺要求高且复杂,在我国重机行业的应用甚为罕见,也缺乏相关的资料和经验.分析这种结构的原理和工艺要点不仅是主轴备件装配工作的需要,还可以丰富特大型冶金企业在类似设备装配与维修方面的经验,为以后R主轴的检修工作提供一定的技术支持及积累.     

沃尔沃铰接头修复及安装工艺

沃尔沃铰卡在井采作业时,工况条件较为复杂,运输作业时铰接处受碰撞频率高,特别是重车的情况下,铰接销孔极易变形及磨损,造成铰接头故障频次高、铰接轴承损坏及铰接销断裂等现象。为了解决这一问题,技术人员对铰接销孔制定出相关修复工艺及措施,并对损坏的铰接头进行了更换,有效地处理了沃尔沃铰接头故障,实现了设备的正常运行。     

一起高压感应电引起的高空触电坠落事故

邯钢动力厂220kV变电站在电气设备春季检修及预防性试验过程中,发生了一起高压感应电引起的触电事故,触电者从7m高的110kV穿墙套管上坠落,当场休克,经抢救脱离生命危险。1　事故经过我厂220kV变电站内110kV配电装置为室内设备,各配出线路通过高压穿墙套管与室内设备相连接。检修当天,要对某110kV线路穿墙套管进行清扫试验,并将套管引线拆除。检修人员将铝合金梯子靠在套管上,然后爬上去拆卸穿墙套管引线在拆卸过程中,没有发生什么异常,当引线拆离套管的瞬间,检修人员突然触电,并从7m高的穿墙套管上坠落下来,当场造成休克。经现场急救并及…     

采矿运输设备的管理及检修方法分析

为了研究采矿运输设备日常检修工作中的优势及目前存在的问题,从自制装置的概念,自制装置的分类,自制装置的特点,自制装置在实际工作中应用的安全意义及其使用注意事项进行分析,并对自制装置在未来设备检修过程中的前景作出建议性说明,一旦输矿设备出现异常或检修期间,对燃料的输入就没有办法保证准确的计算。要想使采矿运输设备得到长期的、安全的运行,就要加强对其维护管理的力度,再加上先进的检修技术应用,可以大大提升运输设备的稳定性。在运输设备产生异常时,对其采取不拆卸的状态下对设备的运行情况进行诊断,从而判断产生异常的设备部位,及时地采取有效的措施进行排除。     

带冷机传动链轮齿圈的剖分组装

为解决带冷机传动链轮齿圈吨位大，在大中修时施工难度较高，现场需整体拆装链轮组等困难，以及减少备件制做所占用的大量维修费用，本文介绍了采用剖分链轮齿圈组装的技术方法。该方法既可减少拆装的工程量，无需采用大型吊装机具，而且还可降低大修工程量并节约备件的制作费用，其组装质量完全能达到技术要求。     

Evidence that a viral replicase protein is involved in the disassembly of tobacco mosaic virus particles in vivo

Tobacco mosaic virus (TMV) particles have been shown to undergo bidirectional disassembly when they are introduced into host cells. Approximately three-quarters of the genomic RNA (i.e., the 126-kDa and 183-kDa protein ORFs) is first uncoated in the 5'-to-3' direction and the process is then completed by removal of coat protein molecules in the 3'-to-5' direction. An effort was made to determine whether the 126-kDa protein or the 183-kDa protein, both of which are involved in replication of the viral RNA, is required for the second part of the disassembly reaction. It was shown that progeny negative-strand viral RNA begins to be produced in inoculated cells at about the same time that 3'-to-5' disassembly is initiated thus suggesting that the two processes may be coupled. Particles containing mutant forms of the viral RNA in which large sections of the 126-kDa and 183-kDa protein ORFs were missing were not disassembled in the 3'-to-5' direction when they were introduced into cells. However, they were disassembled when the inoculum contained purified TMV RNA from which, presumably, the two functional proteins could be translated Particles containing mutants of the RNA from which a few codons had been deleted in or near conserved regions in the 126-kDa protein ORF also did not undergo 3'-to-5' disassembly unless mixed with wild type viral RNA prior to inoculation. These results suggest that the 126-kDa and/or 183-kDa protein plays a role in the completion of disassembly of TMV particles at the onset of the infection process.     

VHMS系统和接口模块在830E-1AC卡车上的应用

小松830E-1AC型电传动卡车作为具有代表性的交流卡车,安装有一套VHMS系统及与其配合进行故障检测、诊断的接口模块。文章主要通过日常积累的经验对其VHMS系统和接口模块的特性及使用方法进行总结,从而对日后设备的维修提供借鉴。     

Temperature-sensitive paralytic mutations demonstrate that synaptic exocytosis requires SNARE complex assembly and disassembly

The neuronal SNARE complex is formed via the interaction of synaptobrevin with syntaxin and SNAP-25. Purified SNARE proteins assemble spontaneously, while disassembly requires the ATPase NSF. Cycles of assembly and disassembly have been proposed to drive lipid bilayer fusion. However, this hypothesis remains to be tested in vivo. We have isolated a Drosophila temperature-sensitive paralytic mutation in syntaxin that rapidly blocks synaptic transmission at nonpermissive temperatures. This paralytic mutation specifically and selectively decreases binding to synaptobrevin and abolishes assembly of the 7S SNARE complex. Temperature-sensitive paralytic mutations in NSF (comatose) also block synaptic transmission, but over a much slower time course and with the accumulation of syntaxin and SNARE complexes on synaptic vesicles. These results provide in vivo evidence that cycles of assembly and disassembly of SNARE complexes drive membrane trafficking at synapses.     

Separation and characterization of microtubule proteins from calf brain

Electrophoresis of microtubule preparations purified from calf brain by repeated cycles of assembly and disassembly shows that they contain many proteins in addition to alpha- and beta-tubulin. These additional proteins constitute about 17% of the total material present after five cycles of assembly and disassembly. Both one-dimensional and two-dimensional (P.H. O'Farrell (1975), J. Biol. Chem. 250, 4007) electrophoretic techniques have been used to characterize them. They can be divided into two groups: one that contains proteins which remain in constant quantitative ratio to tubulin during the purification cycles, and one composed of proteins which are removed during purification, although inefficiently. Gel-filtration chromatography of cold-depolymerized microtubule preparations yields a polydisperse fraction of high molecular weight containing most of the non-tubulin proteins. This fraction contains flexible filaments about 100 A in diameter similar to those reported by R.A.B. Keats and R.H. Hall ((1975), Nature (London) 247, 418). It is suggested that these fibers are neurofilaments, and that they may be the major source of the group of inefficiently removed proteins.     

108t矿用汽车动力总成耦合故障分析

108 t电动轮自卸车动力总成是运矿车正常生产运行的动力源,是构成车辆最根本的总成设备,动力总成使用、维护、检修的好坏,直接关系到运矿汽车的经济效益,十几年来对电动轮自卸车动力总成各种故障进行了综合分析,积累了经验,通过不断的技术学习,对电动轮耦合工艺技术进行了改进,延长了动力总成的使用寿命周期,提高车辆的台年效率。     

In vivo identification of nuclear factors interacting with the conserved elements of box C/D small nucleolar RNAs

The U16 small nucleolar RNA (snoRNA) is encoded by the third intron of the L1 (L4, according to the novel nomenclature) ribosomal protein gene of Xenopus laevis and originates from processing of the pre-mRNA in which it resides. The U16 snoRNA belongs to the box C/D snoRNA family, whose members are known to assemble in ribonucleoprotein particles (snoRNPs) containing the protein fibrillarin. We have utilized U16 snoRNA in order to characterize the factors that interact with the conserved elements common to the other members of the box C/D class. In this study, we have analyzed the in vivo assembly of U16 snoRNP particles in X. laevis oocytes and identified the proteins which interact with the RNA by label transfer after UV cross-linking. This analysis revealed two proteins, of 40- and 68-kDa apparent molecular size, which require intact boxes C and D together with the conserved 5',3'-terminal stem for binding. Immunoprecipitation experiments showed that the p40 protein corresponds to fibrillarin, indicating that this protein is intimately associated with the RNA. We propose that fibrillarin and p68 represent the RNA-binding factors common to box C/D snoRNPs and that both proteins are essential for the assembly of snoRNP particles and the stabilization of the snoRNA.     

APC-mediated proteolysis of Ase1 and the morphogenesis of the mitotic spindle

The molecular mechanisms that link cell-cycle controls to the mitotic apparatus are poorly understood. A component of the Saccharomyces cerevisiae spindle, Ase1, was observed to undergo cell cycle-specific degradation mediated by the cyclosome, or anaphase promoting complex (APC). Ase1 was degraded when cells exited from mitosis and entered G1. Inappropriate expression of stable Ase1 during G1 produced a spindle defect that is sensed by the spindle assembly checkpoint. In addition, loss of ASE1 function destabilized telophase spindles, and expression of a nondegradable Ase1 mutant delayed spindle disassembly. APC-mediated proteolysis therefore appears to regulate both spindle assembly and disassembly.     

轴类零件键槽对称度快速检测专用量具

测量轴类零件键槽对称度时,在游标卡尺的游标外测量爪内侧加装一把测量尺,使外测量爪一长一短,在不破坏原游标卡尺精度的情况下组装出的结构简单、精度高、拆装方便、测量快速的这种测量工具,解决了轴键槽对称度无法直接测量的难题,提高了工效。     

宝钢03线钢卷运输系统故障分析

对宝钢连接热轧厂和冷轧厂的钢卷运输系统电气部分存在的问题和常发故障，进行了较全面的分析与研究，并在ＡＥＧ的原系统上附加一套测定装置，同时修改了ＡＥＧ计算机软件，解决了系统存在的撞车，拒动，磨电道漏电保护跳闸等问题。在现场的实际应用取得了良好的效果。