基于SFB和相关分析法的小电流接地故障选线方法

提出了利用B-样条小波包选择出故障暂态特征最明显的有效频带(SFB),并融合相关分析法对单相接地后各条馈线间的故障暂态波形进行综合相关度分析的方法.利用B-样条小波在阶数增加时具有最优时频窗口的特点,与一般小波分解相比能够更好地提取暂态零序电流信号故障特征,运用相关分析法对各条线路的特征进行分析,正常线路的相关系数较大...     

Wet‐state Ultrasonic Measurements of Cylindrical Workpieces during Immersion Cooling

An ultrasound system was developed for recording the temporally and spatially resolved wetting behaviour of workpieces immersed in oil as quenching medium. The system is based on the measurement of the echo amplitude, reflected from the vapour blanket, the workpiece itself or the vapour bubbles, which occur in the nucleate boiling stage. An optically transparent oil was chosen for the experiments, so that the quenching process could be recorded with a standard CCD‐camera in order to create reference data. The comparison of the duration of the vapour blanket stage calculated from the ultrasonic and the reference data shows a good agreement with respect to the measurement uncertainty. Therefore, the ultrasonic system is applicable in liquid quenching media.     

两种~(18)F标记多肽方法的对比研究

具有生物活性的多肽类药物是目前医用放射性诊疗药物研发的一个热点,开辟了核医学分子影像剂的一个新领域。受体特异性的活性肽具有较好的药代动力学特性,且容易进行结构修饰和放射性标记,受到受体显像和肿瘤靶向性定位领域研究人员的广泛关注。一些多肽类放射性药物已经用于临床及临床前试验,且大量的多肽正有待开发。多肽的放射性标记技术经过多年的发展,已经建立起了系统的方法。通过这些方法获得的放射性药物不会影响多肽的生理活性。本文选用了两种18F标记多肽的方法,通过标记条件、放化产率、标记物的比活度、放化纯度、稳定性及荷瘤鼠体内分布等方面对两种标记方法进行比较研究,为18F标多肽类放射性药物的研究提供借鉴。     

SFB98声幅—变密度测井仪使用问题探讨及解决办法

本文主要讨论SFB98声幅—变密度测井仪在油田实际使用中经常出现的变密度曲线干扰、变密度曲线出现黑白条、声幅曲线出现异常等问题进行分析,并指出产生问题的原因及解决办法。这些经验都是实际工作的总结,也许在今后仪器的维修和使用中有一定的借鉴意义。     

From Single Production Step to Entire Process Chain – the Global Approach of Distortion Engineering

Minimizing or even avoiding of heat treatment distortion is one of the key factors in the machine industry. Although known as a multi‐parameter problem, in the past investigations had focused on single effects or isolated steps in a process chain only. For example segregation patterns in raw materials, forming technologies, machining parameters and quenching was subject of intensive research. A new global approach, treating distortion as a system attribute, analyses the entire process chain from steelmaking to heat treatment. Optimizing distortion by this new methodology is called “Distortion Engineering”, which is the name of the corresponding Collaborative Research Center, established by the Deutsche Forschungsgemeinschaft (DFG) at the University Bremen in 2001. The investigation of “distortion potential” and application of “compensation potential” of different manufacturing steps will lead to an intelligent control of distortion and future improvements in profitability of production.     

多肽T140类似物的~(18)F标记

基质细胞衍生因子(SDF-1)及其受体CXCR4在癌症的发生和转移中发挥着重要作用,因此CXCR4受体可作为诊断癌症的一个潜在靶点。多肽T140是趋化因子受体CXCR4的一种特异性的拮抗剂。我们通过合成中间体[18F]SFB,并和多肽T140的类似物进行偶联,得到18F标记的CXCR4受体显像剂多肽[18F]FB-AcTZ14011,并对标记条件进行了优化。经过HPLC纯化后所得标记多肽的放化纯度大于96%,整个标记用时约3h,放化产率3%(未经衰变校正)。     

基于暂态零序电流特征的小电流接地系统选线的应用方法

小电流接地选线是个难点,采用暂态零序电流的故障特征,实现小电流接地选线是目前配电网的研究热点。在分析小电流接地系统的基本故障特征、零序电流暂态特征和特征频带(SFB)内的相频特性的基础上,介绍了一种基于暂态零序电流特征的选线算法。并对应用中的一些问题做了细致分析,以期能达到借鉴作用。