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971.
数值地震预测的关键物理问题* 总被引:2,自引:0,他引:2
数值地震预测是地震物理研究中的一个重要课题,具有基础性的科学意义和潜在的应用价值.文章介绍了数值地震预测的三个关键物理问题——地震发生率与应力变化的关系、地震断层的摩擦函数、地球中应力的传递问题,讨论了这些问题的意义、研究现状和发展趋势. 相似文献
972.
Abstract The effect of high temperature and high hydrostatic pressure on the residual hydrolytic activity of a commercial Rhizomucor miehei lipase has been studied. Inactivation at high temperature and/or high pressure was carried out. Under non-denaturing pressure conditions, results showed that pressurisation protects enzymes against thermal deactivation. This is in accordance with previous results obtained with enzymes from mesophilic sources, such as invertase and galactosidases. 相似文献
973.
974.
H. D. Hochheimer F. Widulle J. Th. Held G. Strehl R. T. Kotitschke A. R. Adams 《高压研究》2013,33(1-6):41-48
Abstract We present the design of a device for the simultaneous application of uniaxial stress and hydrostatic pressure. This new apparatus will for the first time allow measurements at constant strain. Results of the simultaneous application of uniaxial stress and hydrostatic pressure to a semiconductor laser are presented and discussed. 相似文献
975.
Wilto Kesternich 《辐射效应与固体损伤》2013,168(1-4):261-273
Helium bubble formation was observed in austenitic stainless steels by transmission electron microscopy following implantation of 30 to 1000 appm helium at room temperature and annealing at 700 to 800°C. Helium bubble distributions at dislocations and at various grain boundaries and precipitates were studied. It was found that interfacial dislocations play a dominant role in bubble nucleation at grain and interphase boundaries but not at Tic-matrix interfaces. Particularly high trapping of helium was observed at Tic precipitate-matrix interfaces which is attributed to an inhomogeneous ripening mechanism. 相似文献
976.
We consider a two-dimensional homogeneous elastic state in the arch-like region a?≤?r?≤?b, 0?≤?θ?≤?α, where (r,θ) denotes plane polar coordinates. We assume that three of the edges are traction-free, while the fourth edge is subjected to a (in plane) self-equilibrated load. The Airy stress function ‘?’ satisfies a fourth-order differential equation in the plane polar coordinates with appropriate boundary conditions. We develop a method which allows us to treat in a unitary way the two problems corresponding to the self-equilibrated loads distributed on the straight and curved edges of the region. In fact, we introduce an appropriate change for the variable r and for the Airy stress functions to reduce the corresponding boundary value problem to a simpler one which allows us to indicate an appropriate measure of the solution valuable for both the types of boundary value problems. In terms of such measures we are able to establish some spatial estimates describing the spatial behavior of the Airy stress function. In particular, our spatial decay estimates prove a clear relationship with the Saint-Venant's principle on such regions. 相似文献
977.
Yan Xiaoyan 《The Journal of mathematical sociology》2013,37(4):359-389
A definition of fuzzy clique in social networks is suggested which overcomes five limitations of current definitions. This definition is based on the networks in which the 0–1 strengths, the weighted strengths, and fuzzy strengths are all allowed. The fuzzy distance in such a network is defined. The node‐clique and clique‐clique coefficients are suggested. The core and the periphery of fuzzy cliques are discussed formally. A “cone like” property of the cores is discovered. The network structures are discussed using the new definition. A “no circle” property of networks is found. Basic fuzzy tools and the related algorithms are also discussed. Some examples are analyzed to demonstrate the theory. 相似文献
978.
979.
Analysis of a bi-piezoelectric ceramic layer with an interfacial crack subjected to anti-plane shear and in-plane electric loading 总被引:1,自引:0,他引:1
The behaviour of a bi-piezoelectric ceramic layer with a centre interfacial crack subjected to anti-plane shear and in-plane electric loading has been studied. The dislocation density functions and the Fourier integral transform method have been employed to eliminate the problem of singular integral equations. The normalized energy release rate, stress and electrical displacement intensity factors, G/G0,KIII/KIII0 and KD/KD0, respectively, were determined for different geometric and property parameters by use of two different crack surface electric boundary conditions, i.e. impermeable and permeable. It has been shown that the effects of the thickness and material constants of the piezoelectric layer on all the three parameters, i.e. G/G0,KIII/KIII0 and KD/KD0 were significant. 相似文献
980.
本文报告了楔形钝体分离流区域的湍流实验,提供了分离区内的时均速度、压力,湍流度和雷诺应力的分布,并对分离区的湍流特征进行了分析。实验表明,分离区内时均速度具有很大的横向梯度。湍流度和雷诺应力的分布曲线很相纵,它们在回流区变化较为平缓,而在混合区,当它们达到极大值之后,便以指数形式向(?)衰减。压力在回流区内变化也不大,但在混合区却具有明显的横向梯度。 相似文献