硅砖中裂纹的成因及其分析

制品受到热冲击后内部会出现热应力，当热应力过大时制品中会产生裂纹。硅砖中裂纹包括表面裂纹和层裂。表面裂纹又分为横向裂纹、竖向裂纹和网状裂纹。通常层裂和竖向裂纹是机压所致，横向裂纹和网状裂纹是烧成造成的。影响裂纹生成的主要因素是烧成和机压，但与生产过程有关的其它因素的作用也不容忽视。     

在钢丝的拉拔过程中表面横裂的生成和消除解析

表而裂纹对要求高疲劳特性的弹簧钢是致命的，拉拔线材的表而裂纹对产品质量有重要影响，这类裂纹源自线材在卷取和运输过程中的不良操作。笔者在多道次的不锈钢线材拉拔中，用模拟表而横裂的方法从试验和FEM解析两方而调查了裂纹缺陷的生成和消除。若反复拉拔带有表而裂纹的线材，在压力的作用下，裂纹就轴向变长变细且很小；若反复拉拔带有轴向裂纹的线材，裂纹就变成了检测的标记，此标记是裂纹凹陷在宽度上延伸而成。无论怎样，残留的轴向裂纹会危害产品质量，故必须对此线材进行剥皮处理。     

GCr15轴承钢的生产工艺对其裂纹的影响

滚珠钢产生表面裂纹的原因是很多。表面裂纹的产生是许多原因共同作用的结果，本文以生产滚珠钢的工艺为出发点，从理论和实践两方面阐明了冶炼浇注工序和红送开坯工序是产生裂纹的主要原因，另外，未修磨干净的坯料也为材上带来了裂纹缺陷，最后，提出了降低表面裂纹须从工艺方面采取的措施。     

含铌、钛船板钢中板表面微裂纹研究

对含Nb、Ti船板钢中板表面微裂纹的形成机理进行了研究，结果表明：中板表面微裂纹不是轧制时新产生的裂纹，而是由铸坯微裂纹扩展形成的，铸坯裂纹是在结晶器中形成的沿晶界裂开的表面微裂纹；影响铸坯微裂纹形成的主要因素是钢中铌，钛、铝含量和Cu等低熔点元素含量以及各种应力的作用。     

Q235中板表面纵向裂纹分析

通过生产试验，对Q235中板表面纵向裂纹进行检测和分析。确认了板坯原始裂纹是造成中板边部纵向裂纹的根源。经过对板坯连铸工艺调整和技术攻关，使裂纹缺陷得到有效控制，板坯裂纹缺陷比例由5．3％降到1．4％。     

连铸坯裂纹成因及预防

分析了钢的高温力学性能和作用在连铸坯上的各种应力以及化学成分对铸坯产生裂纹的影响，指出裂纹产生的外因是钢水的静压力，热应力，组织收缩应力和其它外力的作用，当这些应力之和超过了钢的高温临界强度和变形量时，就在凝固前沿或凝固壳中产生裂纹，在二冷区凡是增加共内应力，降低强度和塑性的因素将促进裂纹的发生和扩展，裂纹产生的因是钢的高温力学性能和化学成分，提出了防止连铸坯产生裂纹应从两方面考虑，一是工艺参数和设备运转状态，设法降低连铸坯承受的应变和应变速率，二是钢的化学成分，提高钢水纯净度。     

GCr15轴承钢的生产工艺对其裂纹影响初探

滚珠钢表面裂纹产生的原因很多，表面裂纹的产生是许多原因共同作用的结果。本文以生产滚珠钢的工艺为出发点，从理论和实践两方面阐明了冶炼浇注工序和红送开坯工序是产生钢坯裂纹的主要原因，末修磨干净的坯料为材上带来了裂纹缺陷。同时，提出了降低表面裂纹须从工艺方面采取的措施。 发     

异型坯腹板纵裂纹产生原因分析

针对异型坯的特点，通过对异型坯的凝固特性和应力分析，得出异型坯腹板纵裂纹产生的原因：冷却不均匀造成的温度分布不均匀以及各种复杂应力的集中是产生纵裂纹的根源，结晶组织粗大是产生纵裂纹的诱因，钢中成分和保护渣的性能是纵裂纹形成的重要影响因素。     

304L不锈钢的应力腐蚀

本文研究了３０４Ｌ不锈钢氧氯化反应器上封头的应力腐蚀行为，研究结果表明，材料裂纹的产生是由腐蚀引起。在氯离子作用下首先在硅钙类氧化物夹杂物处发生点蚀，成为裂纹源，然后在应力，氯离子和硫离子三种因素作用下产生裂纹，氯离子和硫离子在裂纹处不断积聚，在应力作用下裂纹扩展，最后导致材料失效。     

连铸板坯中间裂纹的成因分析与改进措施

通过对天铁炼钢厂0^#板坯连铸机现场数据的跟踪分析，对连铸板坯中间裂纹的形成原因和影响因素进行分析和探讨，认为铸机的设备状况是影响中间裂纹的首要和关键因素，钢中硫含量、钢水过热度和拉速也是中间裂纹产生和扩展的影响因素，并据此提出了减少中间裂纹的改进措施。     

Quality assurance and standardized measures--a critical discussion

The debate about quality and quality assurance has a long tradition in the market economy. New in the Federal Republic of Germany, however, is the debate about "quality" in the human services sector: in medical and nursing care, in hospitals and the community, in the health service. This discussion presents practising professionals, politicians and scientists with a number of unsolved problems. This is especially so in defining quality but also in developing, implementing and evaluating appropriate instruments of quality assurance. Quality is far more than what is intended by legislation-economy, productivity and competition- and often conflicts with these expectations. As a consequence, the process of discussion about defining quality turns out to be vague and contradictory rather than systematic, especially since quality cannot be seen as a static component but must be explored as a dynamic element. It is high time to start a critical debate about the concept of quality and current methods of quality assurance.     

Quality assurance under professional law and law relating to health services physicians and doctors

Medical quality assurance is guaranteed by a partially supplementary and partially contradictory systemframework of professional provisions as well as the provisions that apply to health service physicians. As far as qualifications are concerned, quality assurance is primarily the responsibility of the medical boards. Competing provisions are to be found particularly in the area of process quality. With a view to co-ordinating them, the Work Group for the Promotion of Quality Assurance in Medicine has been set up, sponsored by the Federal Medical Board, the Federal Association of National Health Service Physicians, the German Hospital Organisation and the leading statutory health insurance associations. The role of the Federal Medical Board in the field of quality assurance has been considerably upgraded pursuant to the Second Reform Index [II. NOG]. The article refers to several quality assurance projects, exploring in depth, for example, quality assurance in the areas of blood group identification and blood transfusion.     

The Quality Specifications of Mischmetal Wire and Rod and the Method of Adding Rare Earth in Steel

ＴｈｅＱｕａｌｉｔｙＳｐｅｃｉｆｉｃａｔｉｏｎｓｏｆＭｉｓｃｈｍｅｔａｌＷｉｒｅａｎｄＲｏｄａｎｄｔｈｅＭｅｔｈｏｄｏｆＡｄｄｉｎｇＲａｒｅＥａｒｔｈｉｎＳｔｅｅｌ￥ＪｕＹｕａｎ－Ｆｅｎｇ；ＺｕｏＳｈｅｎｇ－Ｈｕａ（ＨｕｂｅｉＣｒｙｓｔａｌｉｎｅＳｉ...     

大型露天矿汽车运输道路质量与运输成本效率

大型露天矿运输道路质量的好坏直接关系到矿用汽车运行成本和运输效率。本文根据德兴铜矿铜厂矿运输道路现状和道路质量对汽车运输的影响及存在的问题进行分析,提出改善运输道路质量,加强生产组织管理,规范筑路工艺技术,合理配置道路养护设施,以及使用合格的筑路的石料的建议,围绕提高道路质量等级[1]和运输效率等方面进行分析,提出“用车先修路、修车养路并重”的理念。     

Modern techniques for quality control and quality management in gynecological health care

Information technologies may contribute in many effective ways to total quality management. Their supporting capacity concerns areas such as clinical documentation and quality control as well as problem analysis, quality assurance and improvement and knowledge management. Here however, a great deficit of the available departmental information systems must be stated.     

Introducing and Managing Quality Scheme for RMC Industry in Saudi Arabia

There is tremendous growth in the use of ready-mixed concrete (RMC) for construction in developing countries. In Saudi Arabia, the production and use of RMC is now widespread, but the quality of concrete construction is still generally substandard. The RMC industry is not regulated or monitored. This has contributed to a general disregard for the basics of good quality as well as cheating by some RMC producers. To rectify the situation and to improve the performance of RMC producers, systematic external monitoring and inspection is required. Recently, the Municipality of Riyadh has started implementing a mandatory quality scheme for RMC plants operating in the city. The scheme was designed considering the difficulties and constraints common to implementing a quality scheme in developing countries. This paper gives details of the quality scheme as developed for RMC in Riyadh, Saudi Arabia. Specifically, the scheme's objectives, its elements, as well as the major difficulties and challenges encountered during its development and implementation are highlighted and discussed. This scheme's impact on the performance of RMC producers and the quality of concrete produced during the first two years are presented. The implementation of the scheme has resulted in tangible improvement in all aspects of RMC operation and product quality. Based on the experience and progress achieved so far, it can be concluded that a mandatory quality scheme can be introduced successfully into the existing RMC industry in developing countries with immediate benefits to the industry and its customers.     

Attentional overload and writing performance: Effects of rough draft and outline strategies.

Preparing a written outline during prewriting and composing a rough 1st draft are strategies that may ease attentional overload and consequently enhance writing performance. The present research examined how these strategies affect the efficiency of the writing process and the quality of the written product. The processing time and cognitive effort given to planning ideas, translating ideas into text, and reviewing ideas and text were monitored by using directed retrospection and comparing secondary-task reaction times. The results of Exp 1 indicated that preparing a written outline, compared with not doing so, led to higher quality documents as indexed by ratings of judges. Composing a rough draft, as opposed to a polished draft, had no beneficial effect on writing quality. Exp 2 showed that a mental outline improved the quality of the documents as much as a written outline, indicating that the written outline was not serving as an external memory aid. Also, both mental and written outlines eased attentional overload by allowing the writer to focus processing time on the single process of translating ideas into text. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Surface Analysis of Chesapeake Bay Water Quality Response to Different Nutrient and Sediment Loads

Based on a set of Chesapeake Bay Estuarine Model (CBEM) scenarios, a three-dimensional response surface of a water quality index, such as chlorophyll concentration, versus a pair of loading constituents, e.g., nitrogen and phosphorus, is constructed. The responses of water quality, such as dissolved oxygen, chlorophyll, and water clarity, to nitrogen, phosphorus, and sediment loads are analyzed. From the response surface, a water quality response is estimated under loading conditions beyond that of a limited set of scenarios. Response surfaces may be used to determine the possible universe of nutrient and sediment load reductions needed to obtain a particular water quality standard and to examine the tradeoffs among nutrient and sediment load reductions that achieve the same water quality objective.     

济钢计量检测体系管理信息系统的设计与应用

济钢计量检测体系管理信息系统对计量检测点上的测量设备按确定的周期组织计量检定,根据计量检测体系的组织机构和管理程序设计了层次式网络结构,从信息的唯一性确定信息的采集模式,应用计算机技术实现了系统的SETUP安装、信息安全系统设计和计量检测体系功能设计,实现了济钢计量检测体系信息化运行。     

IF钢连铸板坯质量评级系统的开发与应用

利用现代数据通讯和数据库技术开发了IF钢板坯质量评级系统。该系统对容易影响铸坯质量的各个生产工艺参数进行实时监测,并将监测结果以质量事件的形式反映到铸流和铸坯上,实现铸坯质量的在线预测。冷轧质量检验结果表明,该系统可以准确地分类筛选出具有不同质量风险的铸坯,确保了O5板对高品质铸坯的要求。