排序方式: 共有8条查询结果,搜索用时 875 毫秒
1
1.
2.
本文通过对南水北调中线总干渠河北段穿越地带膨胀岩土的勘查研究,总结了该区膨胀岩土成因、成分及结构特征,对其胀缩特性以及相关因素进行了分析探讨,并提出了其对南水北调中线工程不良地质现象的防治措施。阐述了用生石灰改良本区膨胀岩土的试验方法和效果。 相似文献
3.
Pulsed-power technology and appropriate boundary conditions have been used to create simulations of magnetically driven astrophysical
jets in a laboratory experiment. The experiments are quite reproducible and involve a distinct sequence. Eight initial flux
tubes, corresponding to eight gas injection locations, merge to form the jet, which lengthens, collimates, and eventually
kinks. A model developed to explain the collimation process predicts that collimation is intimately related to convection
and pile-up of frozen-in toroidal flux convected with the jet. The pile-up occurs when there is an axial non-uniformity in
the jet velocity so that in the frame of the jet there appears to be a converging flow of plasma carrying frozen-in toroidal
magnetic flux. The pile-up of convected flux at this “stagnation region” amplifies the toroidal magnetic field and increases
the pinch force, thereby collimating the jet. 相似文献
4.
开洞薄钢板剪力墙低周反复荷载试验研究 总被引:5,自引:0,他引:5
薄板墙的滞回曲线在零位移附近有零刚度现象,存在明显的捏缩效应,常规方法是直接采用中厚板或通过强大的加劲体系将薄板转化成中厚板,但这将降低薄板墙的经济性。通过两片开洞薄钢板墙低周反复荷载试验,系统地研究了开洞钢板墙的破坏过程和破坏机理,得到了承载力,侧移刚度,延性和耗能能力等指标。试验结果表明,开洞钢板墙有较高的承载力和侧移刚度,延性和耗能能力很好。开洞不仅可以满足门窗洞口等建筑需求,而且可以减小内填板宽度,调节内填板与框架的刚度比,避免薄板墙的捏缩效应,使构件有更高的安全储备,开洞钢板墙是一种理想的水平抗侧力构件。 相似文献
5.
6.
7.
薄层地震响应分析及识别技术 总被引:3,自引:0,他引:3
对薄层地震响应的振幅,频谱等特征进行了详细的分析,并分析了影响该地震的应波形特征的因素。同时,利用积分能谱技术对其进行处理,可以识别出薄层的厚度变化及透镜体的存在。实际应用表明,该项技术较常规的时频分析方法有更高的分辨能力。 相似文献
8.
Sandip K. Chakrabarti 《Journal of Astrophysics and Astronomy》1988,9(4):185-192
We study the effects of the presence of vortex rings surrounding a supersonic radio jet inside the cocoon of a radio lobe.
We show that both the jet and the shocked ambient medium are pinched. Flow speed inside the cocoon is always close to the
sonic value and it stays so by successively passing through several oblique shocks. We also discuss the possibility of the
non-linear growth of the instabilities of the contact surface to explain the numerical results in the literature. 相似文献
1