Travel time tomography inversion and the deep structure of the southern Tibet

ＴｒａｖｅｌｔｉｍｅｔｏｍｏｇｒａｐｈｙｉｎｖｅｒｓｉｏｎａｎｄｔｈｅｄｅｅｐｓｔｒｕｃｔｕｒｅｏｆｔｈｅｓｏｕｔｈｅｒｎＴｉｂｅｔＱＩＮＧ－ＴＩＡＮＬＵ１）（吕庆田）,ＭＥＩ－ＪＩＡＮＧ１）（姜枚）,ＫＡＩ－ＹＩＭＡ１）（马开义）,Ａ．Ｈｉｒｎ２...     

Erosion, sediment transportation and accumulation in rivers

The present paper analyses the interrelation between erosion, sediment transportation and accumulation proposed by N. I. Makkaveyev （1908-1983） and its further development in modem studies of river channel processes in Russia. Spatio-temporal linkages between erosion and accumulation are defined considering channel processes at different scales - river longitudinal profile, channel morphological patterns, alluvial bedforms （bars, dunes） and individual sediment particles. Relations between river geomorphic activity, flow transportation capacity and sediment budgets are established （sediment input and output; channel bed erosion and sediment entrainment into flow - termination of sediment transport and its deposition）. Channel planforms, floodplain segments separated by the latter and alluvial channel bedforms are shown to be geomorphic expressions of sediment transport process at different spatial and temporal scales. This paper is dedicated to the 100th anniversary of N. I. Makkaveyev, Professor of the Moscow State University, author of the book ＂River channel and erosion in its basin＂ （1955）. That book is regarded in Russia as the pioneering work which initiated the complex hydrological and geographical studies of channel processes and laid a basis for the theory of unified fluvial erosion-accumulation process.     

TSIP中期地震预报方法在辽宁地区的应用与研究

本文用ＣＮ算法研究了辽宁省两个地震重点监视防御区的中强震前的强震发生概率增长时间,结果表明预测效果较好,有震报准率为９０％,ＴＩＰ预测警戒占时空率为３０％左右,Ｒ值评分为０．６左右。在ＴＩＰ预测的基础上,进一步用ＳＩＰ方法分析这两个区域的空间背景发震概率的不均匀分布。综合应用ＴＩＰ方法和ＳＩＰ方法,对辽宁省及邻近地区进行了试验性地震预报。     

A Study on Impervious and Heat-Insulating Performance of Geomembrane Composites Within Breakwater

This paper investigates the performance of geomembrane composites used as impervious andheat-insulating lining within a breakwater for a power station.The seepage field,distribution ofstress-strain contour and seepage discharge of hot water which has been treated as the inner thermalsource in the calculation of heat-insulation,have been given by three-dimensional calculation method coup-ling seepage with stress.The results indicate that the impervious and heat-insulation effect ofgeomembrane composites is significant.     

Numerical Model of Total Sediment Transport in the Yangtze Estuary

Based on the non-equilibrium suspended load transport equation,bed load transport equationand sediment transport capacity formulas derived by Dou et al.,a 2-D numerical model of total sedimenttransport in the Yangtze Estuary is presented.In the model,the actions of tidal currents and wind waves andthe effect of salinity on sediment transport are considered.An automatically generated boundary-fitted grid isused to fit the boundaries of the estuary and the boundaries of engineering projects.The verification of calcu-lations shows that the sediment concentration,the deformation of riverbed and siltation in the channels causedby typhoons can be successfully simulated.     

Simulation and Analysis of a Gravity Cyh''''nder''''s Stability in Short-Crested Sea

Generally, the reliability of ami -sliding and anti-overturning stability of an isolated gravity cylinder in a certain working period can be evaluated only when the statistical properties of short term stability are given first. The authors used numerical method to simulate the stability state function of a cylinder in short-crested sea, and further to get the probabilitical characteristics of the structure's stability by time domain analysis. The external loads appeared in the state functions include horizontal wave force, lift force and the respective moments, and the loads are correlated by co- spectrum. The numerical method presented in this paper can be used not only to solve short term reliability problem directly, but to calculate and analyse the long term reliability problem as well. For circular cylinders, an example of simulation and analysis is displayed in this paper.     

Coupling Effect of Riser on Integrated FPS in Deepwater Area

The main challenge in predicting global responses of floating vessels in deepwater and ultra-deepwater areas comes from the system's coupled effect.In this paper,the coupled approach is used to analyze effects of riser on floating system in deepwater.The analysis results show that the coupling effects of risers will mainly affect the low frequency (LF) motions of the system.That is because risers will provide the system with a significant low frequency (LF) damping which will vary with the sea states.Under ...     

应力松弛作用对未固结砂岩等效弹性性质的影响

未固结碎屑砂岩储层是国内外重要的油气储层类型之一,其物理本质是由离散颗粒组成的软凝聚态物质.在地震勘探中通常使用Hertz-Mindlin等效介质模型来计算未固结砂岩的地震弹性特征,但该模型在使用中通常会得到明显偏高的剪切模量值.基于3D离散元技术,对颗粒介质在单轴压缩与纯剪两种过程中的力学响应进行离散元数值模拟,从微...     

ALEXANDRITE AND ITS POPULARITY AS A GEM-STONE IN NORTH CHINA

INTRODUCTION. The reason for having this short paper made public is not so much as to unfold the results of any scientific investigation on the subject matter, but rather as a direct outcome of the response to the repeated inquiries, set     

Computation of Diffraction of Irregular Waves Behind Double Jetty

The coefficient of deffraction of regular waves behind the double jetty has been computed in this paper at first by using the singularity distribution method. The model tests conducted for diffraction of irregular waves with a unidirectional frequency spectrum have confirmed good agreement between the data measured in experiments and the results computed by the singularity distribution method plus the linear superposition method for the energy of component waves in the directional frequency spectra. Therefore, this technique for component waves in the directional spectra has been further used to compute diffraction of irregular waves of multidirection, including the employment of a directional distribution function of the cos2 type, as well as the Bretschneider-Misuyann frequency spectrum.