The role of oxidation damage in fatigue crack initiation of an advanced Ni-based superalloy

The effects of prior oxidation on the room temperature fatigue life of coarse-grained Ni-based superalloy, RR1000, have been investigated. High cycle fatigue tests were conducted, on both machined and pre-oxidised testpieces, at room temperature at an R ratio of 0.1. The oxidation damage was produced by pre-exposures at 700 °C for either 100 or 2000 h. Pre-oxidised testpieces tended to fail with shorter fatigue lives than those obtained from the as-machined testpieces although they were also observed to outperform the as-machined test pieces at peak stress levels around 900 MPa. The chromia scale and intergranular alumina intrusions formed during pre-oxidation are prone to crack under fatigue loading leading to early crack nucleation and an associated reduction in fatigue life. This has been confirmed to be the case both below and above a peak stress level of ∼900 MPa. The better fatigue performance of the pre-oxidised specimens around this stress level is attributed to plastic yielding of the weaker γ′ denuded zone, which effectively eases the stress concentration introduced by the cracking of the chromia scale and intergranular internal oxides. This γ′ denuded zone is also a product of pre-oxidation and develops as a result of the selective oxidation of Al and Ti. Over a limited stress range, its presence confers a beneficial effect of oxidation on fatigue life.     

CS1000P6L型钻机在地表水平钻孔中的应用研究

通过对CS1000P6L型钻机主要技术参数的分析,认为其在0°~45°的倾角范围内实现岩心钻探施工具有一定的可行性。通过对钻机的主要部件——动力头的进一步研究后,选取了一个具体的项目进行了应用实验,针对实验过程中发现的问题,进行了认真分析并加以解决,从而验证了该钻机在0°~45°倾角条件下工作性能的可靠性。还通过对钻机在水平孔施工时的相关配套研究,不仅解决了施工人员的操作平台及钻杆钻具的摆放问题,还解决了钻机在工作中位移控制问题。实践证明,该设备完全可以在0°~45°的倾角范围内实现岩心钻探的施工工作,为该型设备的拓展应用提供了可靠依据,在岩心钻探领域具有良好的推广价值和现实意义。     

无线数字传输技术在煤矿生产中的应用

通过制定通信协议,将现场采集的数据以无线数字方式传输到主控室的上位机,实现了在远离生产现场的控制室对现场的温度、湿度、流量等进行监控,并经模拟运行证实。     

AP1000空气导流板垂直密封件制造质量控制研究

通过三门1#堆AP1000空气导流板垂直密封件制造的质量控制，总结了垂直密封件在制造过程中影响产品质量的两个技术难点，其一是折弯精度对产品质量的影响；其二是焊接变形对产品质量的影响。通过分析，确定了影响折弯精度和焊接变形的关键要素，提出了相应的控制方法。产品制造实践证明了这些变形控制方法的可行性和有效性，从而确保了产品的质量。本文总结的折弯精度控制和焊接变形控制方法对其他中厚型碳钢钢板在制造过程中的变形控制也有一定的借鉴意义。     

AP 1000 核电工程文件编码体系介绍与优化建议

介绍了AP1000核电工程文件编码程序的主要内容及其创新性特点,结合工程实际,分析了涉及两重定位码的部分文件或图纸在编码过程中无法有效选定定位码从而导致文件或图纸编码信息不全面的问题,并且针对该问题提出了相应的优化建议方案和研究方向。     

AP1000 SGTR始发安全壳旁路型严重事故裂变产物行为分析

建立非能动先进堆AP1000的事故分析模型,选取蒸汽发生器传热管破裂(SGTR)始发的安全壳旁路型严重事故,在研究事故进程的基础上,分析计算事故下裂变产物释放和迁移的特性,重点关注惰性气体、挥发性裂变产物和非挥发性裂变产物的分布,以及裂变产物在主系统和环境中的状态,最终计算释入环境的源项.     

A two-stage shape retrieval (TSR) method with global and local features

A robust two-stage shape retrieval (TSR) method is proposed to address the 2D shape retrieval problem. Most state-of-the-art shape retrieval methods are based on local features matching and ranking. Their retrieval performance is not robust since they may retrieve globally dissimilar shapes in high ranks. To overcome this challenge, we decompose the decision process into two stages. In the first irrelevant cluster filtering (ICF) stage, we consider both global and local features and use them to predict the relevance of gallery shapes with respect to the query. Irrelevant shapes are removed from the candidate shape set. After that, a local-features-based matching and ranking (LMR) method follows in the second stage. We apply the proposed TSR system to MPEG-7, Kimia99 and Tari1000 three datasets and show that it outperforms all other existing methods. The robust retrieval performance of the TSR system is demonstrated.     

百万机组开展基建期环保监督工作的探讨

介绍了在国华宁海2×1000 MWe机组开展基建期环保监督的情况,主要阐述了基建期环保监督的内容和方式,对重要节点采取的监督措施,以及在宁海工程中发现的问题及处理情况。通过基建期监督的开展,提高了基建阶段环保设备与仪表的安装调试质量,减少了移交生产时的遗留问题。随着环保方面要求日趋严格,开展基建过程环保质量技术监督模式将会得到推广和完善。     

APl000主管道的国产化试制和制造许可证审评

描述了APl000主管道的制造技术要求，对国内近期APl000主管道热段的研制情况进行了综述，介绍了目前APl000主管道制造许可证的申请和颁发情况。     

格非Magi1000自动播出系统主备数据库同步和快速切换

结合实际使用，简单介绍北京格非Magi1000板卡式硬盘自动播出系统主备数据库同步和切换的方法以及存在的不足，给出了用Delphi7．0编写主备数据库服务器快速切换软件的方法和关键代码，减少了维护工作量，确保播出系统安全不问断运行。