Transient Response in Cross-Ply Laminated Cylinders and Its Application to Reconstruction of Elastic Constants

An efficient hybrid numerical method is presented for investigating transient response of cross-ply laminated axisymmetric cylinders subjected to an impact load. In this hybrid numerical method, the laminated cylinder is divided into layered cylindrical elements in the thickness direction. The Hamilton principle is used to develop governing equations of the structure. The displacement response is determined by employing the Fourier transformations and the modal analysis. Numerical examples for analyzing transient waves have been provided in axisymmetric laminated cylindrical structures, both for thin cylindrical shells and thick cylinders.
A computational inverse technique is also presented for reconstructing elastic constants of axisymmetric crossply laminated cylinders from the surface displacement response data, using the present hybrid numerical method as the forward solver and neural network as the inverse operator. This technique is utilized to reconstruct the elastic constants of an axisymmetric laminated cylindrical shell.     

An Evaluation Model for the Coordinated Development of a Circular Economy in China and Its Application to Energy-intensive Industries

Energy-intensive industries (EIIs) are fundamental to the industrial development of China and are also the key industries of a circular economic infrastructure. It is worth paying attention to the coordinated development of a circular economy using EIIs due to the present interrelationship among EIIs. It is related to the optimization and comprehensive performance improvement of a circular economy. Based on the perspective of order parameter, this study uses economic and environmental subsystems to establish an evaluation model that examines the coordinated development of a circular economy within six main EIIs and an EII cluster from 2006 to 2011 in China. The result shows that the level of coordinated development in a circular economy among six EIIs differs and the level of coordinated development of circular economy among the EII cluster lags behind that of each EII examined. It also shows that the outside coordinated degree of EIIs is lower than the inside coordinated degree of each EII.     

Application of fuzzy logic in the selection of part orientation and probe orientation sequencing for prismatic parts

With an increase in complex designs and tighter tolerances, the Coordinate Measuring Machine inspection process has become increasingly more advanced. By inspection planning, design data can be transferred to an inspection system and an entire inspection operation can be carried out with a minimum of time and with reduced uncertainty. The current need is to automate this process completely so that the inspection plan can be generated directly from the design information. Two modules of inspection planning, i.e. selection of part orientation and probe orientation sequencing, have not been dealt with properly. Also, some important factors for the selection of part orientation have been neglected and proper weights have not been given to the probe-orientation sequencing criteria. An attempt was made to overcome these limitations. Both problems have been approached as the ranking of a number of alternatives based on multiple criteria, where each criterion has unequal importance. To get the optimum probe-orientation sequence and stable part orientation, fuzzy logic was applied. Fuzzy sets were obtained and combined using a suitable methodology. To explain and validate the proposed methodology, an example part was taken. As a practical case, an engine block was considered and the results presented.     

优化EMD法及其在航空发动机振动信号分析中的应用

针对脉冲噪声和随机噪声对经验模式分解所产生的模式混叠和端点效应问题,提出了一种中值滤波-奇异值分解(Median Filter-Singular Value Decomposition,简称MF-SVD)联合降噪的优化经验模式分解方法.利用中值滤波对脉冲噪声的去除能力和SVD对随机噪声的抑制能力,同时为了解决SVD降噪中降噪阶次难以确定的问题,提出了能量差分谱的概念改善了SVD降噪能力.联合中值滤波和改进后的SVD降噪方法去除脉冲噪声和随机噪声干扰,有效改善经验模式分解质量.将该方法应用到航空发动机振动试飞数据分析中,很好地获取了表征自由涡轮转子和燃气发生器转子振动特征的数据分量,有效抑制了模式混叠和端点效应,验证了优化经验模式分解方法应用的有效性.     

一种新型萃取装置及其在水样挥发酚测定中的应用

本文介绍一种新型萃取装置,由磁力搅拌器、三角烧瓶和经改造的活塞组成。此装置已用于挥发酚的测定中。大量实验数据表明,该装置优于常规分液漏斗,克服了使用分液漏斗中常见的易漏、重现性差、工作强度大等缺点。其准确度,重现性,工作曲线相关性均较好,是一种可以取代分液漏斗,用于各类常规分析的理想玻璃仪器。     

红薯淀粉基微球的制备及其对污水中Cu~(2+)的去除研究

以红薯粉为原料、Span 60与Tween 60为乳化剂、N,N-亚甲基双丙烯酰胺(MBAA)为交联剂,采用反相乳化交联法制备淀粉微球,用红外光谱仪(FT-IR)、扫描电镜(SEM)及比表面积和孔径分析仪对其进行表征和分析,并对模拟Cu~(2+)污水进行吸附测试,探寻最佳吸附条件,并将最优吸附条件应用于西安汉城湖水样的Cu~(2+)吸附测试。研究发现,制备的红薯淀粉微球的结构良好,且当淀粉微球投入浓度为0.12 g·m L-1、吸附时间为45 min时,吸附效果最佳;汉城湖水样测试显示,Cu~(2+)去除率达到82.45%。