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741.
Based on the theory of elastic wave propagation in saturated soil subgrade established by the author of this paper, the axisymmetric
vertical vibration of a rigid circular foundation resting on partially saturated soil subgrade which is composed of a dry
elastic layer and a saturated substratum is studied. The analysis relied on the use of integral transform techniques and a
pair of dual integral equations governing the vertical vibration of the rigid foundation is listed under the consideration
of mixed boundary-value condition. The results are reduced to the case for saturated half-space. The set of dual integral
equations are reduced to a Fredholm integral equation of the second kind and solved by numerical procedures. Numerical examples
are given at the end of the paper and plots of the dynamic compliance coefficient Cv versus the dimensionless frequency a0 are presented.
Foundation item: the National Natural Science Foundation of China (59579018)
Biography: CHEN Sheng-li (1974-) 相似文献
742.
743.
744.
745.
对现有连续统场论中存在若干有关兼容性问题进行了简略的评论.根据重建的极性的连续统基本定律阐述三类兼容性问题.第一类是讨论各基本定律间的兼容性问题.第二类是讨论微极连续统基本定律兼容一般连续统基本定律的问题.第三类是讨论微极连续统基本定律兼容刚体动力学基本方程的问题.推导出的结果有助于深刻理解各种连续统理论的基本定律体系的结构和它们之间的联系.明确地指出,在传统的连续统场论的基本均衡定律的框架下,相容性问题是不可能自然地得到解决. 相似文献
746.
747.
V. P. Perelygin O. S. Zaveriukha B. N. Kulakov M. I. Krivopustov I. G. Abdullaev G. P. Knjazeva R. I. Petrova R. Brandt M. Ochs J. S. Wan P. Vater 《Radiation measurements》2001,34(1-6):287-291
Experiments with relativistic protons accelerated at the Synchrophasotron LHE, Dubna, with energies of 0.5, 1.0, 1.5, 3.7 and 7.5 GeV hitting massive targets of (nat. U)/Pb and Pb were carried out using SSNTD during the years 1996–1999. The beam profiles and intensities of both primary particles and fast secondary neutrons were measured inside the massive cylinder blocks of Pb and U by counting fission fragment tracks due to the induced fission of Pb nuclei. The beam diameter typically increases by 20–30% at the depth 10 and 20 cm. With increasing the energy of protons the number of secondary neutrons increases with the depth of the target.
Further studies on beam profile measurements inside the massive heavy metal targets are discussed. 相似文献
748.
Hailiang Zhang Xiaoyi Sun Xiayu Wang Qi‐Feng Zhou 《Macromolecular rapid communications》2005,26(5):407-411
Summary: A novel ABC triblock copolymer with a rigid‐rod block was synthesized by atom transfer radical polymerization (ATRP). First, a poly(ethylene oxide) (PEO)‐Br macroinitiator was synthesized by esterification of PEO with 2‐bromoisobutyryl bromide, which was subsequently used in the preparation of a poly(ethylene oxide)‐block‐poly(methyl methacrylate) (PEO‐b‐PMMA) diblock copolymer by ATRP. A poly(ethylene oxide)‐block‐poly(methyl methacrylate)‐block‐poly{2,5‐bis[(4‐methoxyphenyl)oxycarbonyl]styrene} (PEO‐b‐PMMA‐b‐PMPCS) triblock copolymer was then synthesized by ATRP using PEO‐b‐PMMA as a macroinitiator.
749.
动力刚化与多体系统刚—柔耦合动力学 总被引:25,自引:2,他引:23
首先指出当前柔性多体系统动力学的大量工程研究背景,在回顾柔性多体系统动力学研究进展后指出动力刚化的现象揭示了刚-柔耦合的零次建模方法的局限,认为进一步深入进行柔性多体系统刚-柔耦合动力学的研究是多体系统动力学研究的新阶段,文末提出了刚-柔耦合动力学的研究任务。 相似文献
750.
A. A. Pan'kov 《Mechanics of Composite Materials》1999,35(5):419-428
The boundary-value problem in the correlative approximation of the method of quasi-periodic components and a numerical algorithm
based on the boundary element method for determining the nonuniform stress fields in the matrix of a unidirectional fiber
composite with a disordered structure are considered. The numerical results and analysis of the probability density function,
for example, for normal stresses at some points of the interface of absolutely rigid fibers of the composite are presented.
Perm State Technical University, Russia. Translated from Mekhanika Kompozytnykh Materialov, Vol. 35, No. 5, pp. 629–642, September–October,
1999. 相似文献