Frequency Analysis of Heavy Tamping Vibration

ＩＮＴＲＯＤＵＣＴＩＯＮＢｅｃａｕｓｅｏｆｉｔｓｓｉｍｐｌｅｏｐｅｒａｔｉｏｎａｎｄｌｏｗｃｏｓｔａｓｗｅｌｌａｓｅｆｆｅｃ ｔｉｖｅｎｅｓｓｆｏｒｍａｎｙｐｒｏｊｅｃｔｓ ,ｈｅａｖｙｔａｍｐｉｎｇｈａｓｂｅｅｎｕｓｅｄｗｉｄｅｌｙｉｎｔｈｅｗｏｒｌｄ (Ｑｉａｎｅｔａｌ.,1986 ) .Ｈｏｗｅｖｅｒ,ｔｈｅｓｔｒｏｎｇｖｉｂｒａｔｉｏｎｉｎｓｏｉｌｍａｓｓｃａｕｓｅｄｂｙｈｅａｖｙｔａｍｐｉｎｇｍａｙｂｅｈａｒｍｆｕｌｔｏｂｕｉｌｄｉｎｇｓ,ｉｎｓｔｒｕｍｅｎｔｓａｎｄｅｖｅｎｈｕｍａｎｂｏｄｉｅｓａｒ…     

国外中期数值预报业务模式的性能及发展趋势

作者简单介绍了国内预报员较为熟悉的欧洲中期天气预报中心，美国国家气象中心和日本气象厅三个中期预报模式的性能及预报效果，包括近几年颇为流行的半拉格朗日时间积分方案，物理过程参数化方案的完善和改进，中期数值预报业务模式的发展趋势等。     

南方大到暴雪的一种预报方法

对构成南方大到暴雪的两个特征量：降水量和积雪深度用多种预报方法从晴雨、降水性质、降水量级、冰冻及积雪厚度等不同角度分别进行预报，然后通过推理组合，最终建立暴雪预报方法。该方法除了可以得出有无大到暴雪的预报结果外，还可以得到多种中间预报结果，从而适应预报服务的多种需要。在近３年的实际使用中获得了很好的效果。     

“05．6”广西持续性大暴雨成因分析

利用常规资料、T213初始场及6h预报场、卫星云图等资料，用中尺度分析方法，并配合诊断分析，对广西“05.6”持续性大暴雨成因进行了初步探讨。结果表明：这次过程是在稳定的大尺度环流形势和有利的物理量场条件下发生，是大、中尺度天气系统相互作用的结果，具有典型的中尺度性质，表现出强降雨的不均匀性、突发性和局地性，是中尺度天气系统活动的结果。     

Barothropic relaxing media under pressure perturbations: Nonlinear dynamics

In this paper, we delve into the dynamics of a barothropic relaxing medium under pressure perturbations originating from blast wave explosions in the milieu. Analyzing the problem within the viewpoint of the Lyakhov formalism of geodynamic systems, we derive a complex-valued nonlinear evolution equation which models the wave propagation of the pressure perturbations within the barothropic medium. As a result, we find that the previous system can be circularly polarized and hence support traveling rotating pressure excitations which profiles strongly depend upon their angular momenta. In the wake of these results, we address some physical implications of the findings alongside their potential applications.     

黑龙江省中尺度数值预报业务系统

黑龙江省气象台于2001年8月引进了MM5模式，并结合业务和服务的实际需要对其有关参数进行了确定，建立了黑龙江省中尺度数值预报业务系统。已经在黑龙江省气象台实时运行，并应用到短期预报的业务工作中。系统运行稳定，预报结果有一定的参考价值。     

一次秋季局地强降水过程分析

对常规气象要素、卫星云图和T106物理量诊断产品进行分析,得出2001年10月2～3日发生在桂东南局地强降水成因及中尺度系统特征。     

Approximation of interfacial properties in multiphase porous medium systems

We investigate the estimation of interfacial areas, curvatures, and common curve lengths in multiphase porous medium systems. Algorithms are developed to obtain estimates of these quantities based upon a variety of potential data sources and estimation approaches. The accuracy of the derived approximations are evaluated as a function of the data type and resolution of the data. The methods advanced improve upon standard approaches now in use and show excellent accuracy at resolutions on the order of five lattice points per minimum radius of curvature of the object being resolved. Finally, we suggest a promising class of extensions that could lead to further improvements in the accuracy of such methods.     

Inversion of interference hydraulic pumping tests in both homogeneous and fractal dual media

This work proposes a complete method for automatic inversion of data from hydraulic interference pumping tests based on both homogeneous and fractal dual-medium approaches. The aim is to seek a new alternative concept able to interpret field data, identify macroscopic hydraulic parameters and therefore enhance the understanding of flow in porous fractured reservoirs. Because of its much contrasted sensitivities to parameters, the dual-medium approach yields an ill-posed inverse problem that requires a specific optimization procedure including the calculation of analytical sensitivities and their possible re-scaling. Once these constraints are fulfilled, the inversion proves accurate, provides unambiguous and reliable results. In the fractal context inverting several drawdown curves from different locations at the same time reveals more accurate. Finally, hydraulic parameters drawn from inversion should be taken into account to improve in various situations the conditioning of up-scaled flow in fractured rocks.     

昆仑山Ms 8.1级地震震后变形场数值模拟与成因机理探讨

2001年11月14日,在青海和新疆交界处发生了昆仑山M_s8.1级强烈地震,GPS后观测显示,此次地震震后形变不仅在断裂南北两侧存在很大的差异,而且在短时间调整后断裂南北两侧表现为同向运动.本文以观测的地震形变为约束,通过有限元数值模拟分析昆仑山地震震后形变的物理机制.建立有关的有限元虚功方程,通过有限元数值方法模拟震后形变,从理论上分析介质的非均匀性、黏滞性松弛、流体调整对震后形变的影响.采用网格搜索确定昆仑断裂南北两侧下地壳的黏滞系数分别为5.0×10¹⁷Pa·s, 9.0×10¹⁸Pa·s左右,正是这十余倍的差异引起了断裂两侧震后形变的非对称性和同向运动,这一差异既是长期地质作用的结果,又是现代地球动力学环境的决定因素之一.通过数值模拟定性讨论了断裂北侧地表形变在震后短期内的调整,对于靠近断裂附近的测点可能是黏弹性松弛和孔隙流体调整共同作用的结果,所以在分析短期震后形变时综合考虑黏弹松弛和孔隙流体调整是很有必要的.