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101.
Based on the governing equation of vibration of a kind of cylindrical shells written in a matrix differential equation of the first order,a new matrix method is pre- sented for steady-state vibration analysis of a noncircular cylindrical shell simply sup- ported at two ends and circumferentially stiffened by rings under harmonic pressure.Its difference from the existing works by Yamada and Irie is that the matrix differential equation is solved by using the extended homogeneous capacity precision integration ap- proach other than the Runge-Kutta-Gill integration method.The transfer matrix can easily be determined by a high precision integration scheme.In addition,besides the normal interacting forces,which were commonly adopted by researchers earlier,the tan- gential interacting forces between the cylindrical shell and the rings are considered at the same time by means of the Dirac-δfunction.The effects of the exciting frequencies on displacements and stresses responses have been investigated.Numerical results show that the proposed method is more efficient than the aforementioned method. 相似文献
102.
A fundamental solution for half-plane problems which will play a key role in calculation of the stress concentration around a hole embedded in half-plane is derived by a method combining images with direct integrations. It is wore intuitive than the Fourier transform method used by Gladwell[6]. In addition, the principle and procedure of boundary element method to solve the half-plane problems are also presented by means of Betti’s reciprocal theorem in this paper.It is shown that the. computing procedure for half-plane problems is much more convenient using the fundamental solution presented here than the one adopted by C.A. 相似文献
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李昆刘盈斐徐静赵晓辉 《化学分析计量》2023,(1):50-55
针对地表水、地下水及饮用水中9种烷基酚类化合物的含量检测,建立了一种适合于气相色谱-质谱分析的衍生化方法。分别对样品预处理的衍生化温度、反应时间、水体样品pH、洗脱溶剂类型及用量进行优化。优化结果表明,烷基酚类化合物的质量浓度在20.0~1 000μg/L范围内与色谱峰面积具有良好的线性关系,线性相关系数均不低于0.999 1,方法检出限为4.49~9.46 ng/L。地表水、地下水及饮用水样品加标回收率为77.6%~98.8%,测定结果的相对标准偏差不大于11.4%(n=7)。该方法适用于地表水、地下水及饮用水中烷基酚类化合物的检测。 相似文献