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对AP1000压水堆核电站安全壳贯穿件的非径向管板焊接接头结构特点进行了介绍,并分析其超声检测工艺的重点和难点。通过建立统一的缺陷定位坐标系并结合被检构件的几何特点进行综合分析,推导得出了h值(缺陷回波最高点距套管外壁的距离)的计算方法。为超声检测对这类焊接接头缺陷的准确识别和定位提供了行之有效的方法,为解决这类焊接接头的超声检测技术受限区提供了行之有效的措施。 相似文献
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The primary objective of this study is to develop teaching materials for chemical engineering students (or students pursuing other related B.Sc./M.Sc. degrees) that encourage self-learning to facilitate understanding and the development of problem-solving skills. Tools are oriented to support the teaching of “Introduction to Chemical Engineering” courses to 1st year B.Sc. students in Chemical Engineering, 2nd year B.Sc. students in Chemistry, and 3rd year B.Sc. students in Biochemistry at the Universidad Complutense de Madrid (UCM). Problem generators of standard exercises, as an additional complement to the exercises that are used in the lectures, seminars, and assignments to facilitate the learning of the students, have been developed. These generators provide exercises to students with “unlimited” initial values (with certain restrictions). The software that was used to develop these materials was Jupyter Notebook, which runs under the Python 3.6 language. The problem generators can be classified into fixed problem generators, case-based generators, and random problem generators. Additionally, lecturing tools have been developed to support teaching using live/interactive examples. These examples can learning understanding of various topics of the courses. 相似文献
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The corrosion resistance of aluminium surfaces is closely linked to the surface state after a grinding process. For years, iron-containing abrasive materials were suspected to lead to increased corrosion susceptibility after processing of aluminium surfaces. To prove a possible correlation between the iron content of an abrasive and the corrosion behaviour of aluminium components, scientific investigations and experimentally practical corrosion tests are necessary. For the current investigation, specimens of a technical Al-Si alloy from the same batch were used. The test specimens were mechanically ground with various resin-bonded model abrasives containing different iron contents. The performed corrosion tests did not reveal a negative influence of the different iron-containing abrasives on the corrosion behaviour of the Al–Si alloy. However, the most sensitive measuring method (electrochemical noise) showed differences in the surface activity depending on the type of abrasive. 相似文献
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Integration testing is to ensure that each functional module is correct and performs well, so that these modules can be as-
sembled together to work well. The manual testing method of the tester alone cannot effectively evaluate the tested aviation soft-
ware, and the use of advanced automated testing tools can overcome these difficulties. This paper introduces the method and process
of integration testing with Testbed suite tool TBrun through a practical test project. 相似文献
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防碰装置是起重机械重要的安全防护装置,其性能质量直接关系到人员和设备安全。常规的防碰装置性能试验方法难以保证试验数据的精度和可靠性。针对防碰装置的工作特点和试验要求,从试验原理、系统结构、运行逻辑等方面入手,设计一套能模拟防碰装置实际运行工况,自动进行性能试验和数据采集处理,精度高、重复性好的试验系统,可以有效提升防碰装置检测能力。 相似文献
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Software updates are an important topic for increasingly software dependent and automated automotive systems. Besides ongoing technical developments, there are also regulatory requirements in development for such systems. We present here an overview of the automotive domain and the particular requirements on update systems, identify potentially suitable update frameworks and evaluate them based on automotive requirements. A focus is on a holistic view of requirements, considering safety, security, and availability. 相似文献
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ABSTRACTLearning parameters of a probabilistic model is a necessary step in machine learning tasks. We present a method to improve learning from small datasets by using monotonicity conditions. Monotonicity simplifies the learning and it is often required by users. We present an algorithm for Bayesian Networks parameter learning. The algorithm and monotonicity conditions are described, and it is shown that with the monotonicity conditions we can better fit underlying data. Our algorithm is tested on artificial and empiric datasets. We use different methods satisfying monotonicity conditions: the proposed gradient descent, isotonic regression EM, and non-linear optimization. We also provide results of unrestricted EM and gradient descent methods. Learned models are compared with respect to their ability to fit data in terms of log-likelihood and their fit of parameters of the generating model. Our proposed method outperforms other methods for small sets, and provides better or comparable results for larger sets. 相似文献