十万立方储罐的四机联照射线检测

十万立方储罐是我国新研制的一种大型储罐,由于采用新工艺安装,施工速度很快,给无损检测带来很大压力。为保证射线检测进度,通过多方调研制,作出四机联合拍照架,此架结构简单,成本低廉,有极强的实用性。多个现场实际应用表明,该方法极大地提高了检测效率,拍片质量也符合相关标准要求。     

Evaluating expectations about negative emotional states of aggressive boys using Bayesian model selection.

Researchers often have expectations about the research outcomes in regard to inequality constraints between, e.g., group means. Consider the example of researchers who investigated the effects of inducing a negative emotional state in aggressive boys. It was expected that highly aggressive boys would, on average, score higher on aggressive responses toward other peers than moderately aggressive boys, who would in turn score higher than nonaggressive boys. In most cases, null hypothesis testing is used to evaluate such hypotheses. We show, however, that hypotheses formulated using inequality constraints between the group means are generally not evaluated properly. The wrong hypotheses are tested, i.e.. the null hypothesis that group means are equal. In this article, we propose an innovative solution to these above-mentioned issues using Bayesian model selection, which we illustrate using a case study. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

In Vivo and In Vitro Degradation Behavior of Magnesium Alloys as Biomaterials

The corrosion behavior of pure Mg,AZ31,and AZ91D were evaluated in various in vitro and in vivo environments to investigate the potential application of these metals as biodegradable implant materials.DC polarization tests and immersion tests were performed in different simulated body solutions,such as distilled(DI) water,simulated body fluid(SBF) and phosphate buffered solution(PBS).Mg/Mg alloys were also implanted in different places in a mouse for in vivo weight loss and biocompatibility investigations.The in vivo subcutis bio-corrosion rate was lower than the corrosion rate for all of the in vitro simulated corrosive environments.The Mg/Mg alloys were biocompatible based on histology results for the liver,heart,kidney,skin and lung of the mouse during the two months implantation.Optical microscopy and scanning electron microscopy were carried out to investigate the morphology and topography of Mg/Mg alloys after immersion testing and implantation to understand the corrosion mechanisms.     

声学综合无损检测技术

论述了检测复合材料和胶接结构不连续（缺陷）的新型多模综合无损检测技术。该技术以声与超声检测技术为基础,包含五种不同检测模式,用以检测复合材料与胶接结构的失粘、脱粘、分层、疏松、夹芯压皱及其他缺陷。它适用于复合材料与构件的制造、维修和使用现场。它的适用对象范围广泛,几乎覆盖了现有常用的复合材料和胶接结构。它的检测可靠性高,重复精度好。文章还讨论了组成多膜声学综合胶接检测仪的五种不同检测模式的原理,并从我们和国内外同行的大量实践经验出发,说明了综合无损检测技术的巨大发展前景。     

面向软件黑箱测试的仿真环境嵌入故障研究

故障注入作为软件测试的一种有效技术已进入实用阶段, 然而如何在软件黑箱测试中运用故障注入技术目前尚少有文献加以论述.文章提出了软件黑 箱测试中故障外围注入的思想,通过嵌入故障的仿真环境,实现对被测软件输入级的故障引入 ,改变软件的运行状态,诱发内在的失效模式,导致错误的输出,从而达到预期的测试目的.这 一方法已应用于铁路车站信号控制系统软件的测试中,并取得了良好的效果.     

认识全色密度计在射线检测中的作用

由国家计量部门相关政策变更所引发的一系列问题,给射线检测结果带来诸多变数,也直接影响到检测的质量。启用兰片基标准密度片奖有助于广大密度计用户及时发现问起,并找到解决问题的好方法。     

电力系统稳定性计算用励磁系统数学模型的完善

在已有电力系统稳定性计算用励磁系统数学模型(以下简称:励磁模型)的基础上,结合励磁系统的调研和参数测定工作,对励磁模型进行了4个方面的改进与完善;增加了并联PID控制;增加了PID控制的限幅环节;对原有晶闸管整流器模型进行了补充修订;对低励限制环节(UEL)的限制曲线设置进行了修改。     

配网自动化终端之精度、功能、通信协议综合检测技术研究

针对我国配网自动化终端缺少全面而有效的检测手段的实际情况,介绍了一种配网自动化终端综合检测方案.其检测平台由主站模拟系统、多通道接口、被测终端和现场工况模拟系统组成,实现了集基本误差、通信协议检测、功能检测于一体的多功能检测,使被测终端的综合检测成为了可能.该平台的研制对进一步规范和保证终端的功能,提高测试效率,提升检测水平,有一定的参考价值.     

Hard-Fault Detection and Diagnosis During the Application of Model-Based Data Converter Testing

The concept of model-based test was developed in order to reduce the production test effort for data converters (Cherubal and Chatterjee (IEEE Trans Circuits Syst part I 50(3):317–327, 2003); Stenbakken and Souders (1985) Modelling and test point selection for data converter testing. In: ITC, Int Test Conf, pp 813–817; Wegener and Kennedy (IEEE Trans Circuits Syst I 51(1):213–217, 2004); Wrixon and Kennedy (IEEE Trans Instrum Meas IM-48(5):978–985, 1999)). In applying this concept, a vector of model parameters is determined for each device under test (DUT). Typically, this model parameter vector is merely used to calculate the DUT performance characteristic which is then subject to specification-oriented testing. However, each element of the model parameter vector represents an independent error source which contributes to performance degradations; thus, the model parameter vector can be viewed as a signature of the error sources. In this work, analyzing the error source signature is used to devise a model-based methodology for hard-fault detection and diagnosis. We investigate conditions under which hard-faults are detectable/diagnosable in spite of masking effects due to manufacturing process variations. In particular, we show that taking the model parameter vector as the fault signature is optimal as it minimizes the masking effects and thus maximizes detectability/diagnosibility.

GaAs功率单片脉冲在片测试技术研究

讨论了功率单片在片脉冲测试中在片校准技术、脉冲功率测试技术等难题,并在讨论以上问题的基础上,实现工程化应用,该测试技术能够有效覆盖至40GHz。在建立的脉冲大功率在片测试系统上对输出功率典型值5W的GaAs功率单片放大器进行测试验证,测试结果和装架测试结果相比较,输出功率误差<0.2dB。