储液池的抗震问题探讨

应用流体固体动力耦合统一分析模型的有限元法，进行了储液池的抗震分析。分别探讨了储液池内液体的液面大幅波动、池壁刚度变化、池的深宽比等对地震响应的影响。研究结果表明：储液池壁刚度是比较敏感的物理量，弹性比刚性池壁与液体相互作用的非线性行为强，池壁所受流体的作用力大；液面波的影响也有同样规律，刚性池壁情况下考虑面波与否影响不太大，但弹性池壁却有较大影响；另外宽池比窄池的响应强。     

Decoupling Conditions for Elasto-plastic Consolidation Question Based on Numerical Modeling Method

INTRODUCTION Theconsolidationofsaturatedsoilisanimpor tantsubjectingeomechanics.Biot(1941)proposed thethree dimensionalconsolidationtheory,whichis basedontheprincipleofeffectivestress,continuity conditionsandequilibriumequations.Theremarka blesuccessofthistheoryistheanalysisofthetime dependenteffectandcouplingeffectofsoilandpore water.Thus,thetheoryisaclassictheoryinsatu ratedsoilstatistics.Itwasalmostunfeasibletoperformanalysesof thistheorywithoutthedevelopmentofhigh speed computersandnu…     

山地灾害与山地生态环境演变相互耦合作用——以昆明市东川区为例

通过对泥石流灾害典型区云南省昆明市东川区山地自然环境和人类经济活动即土地利用状况的剖析，分析了东川区泥石流灾害暴发频率和强度，以及其灾害的兴衰与山地自然环境和人类经济活动互为耦合作用的关系。当人们加大环境修复力度和合理地利用山地土地资源时，可以在一定程度上控制泥石流灾害，并达到优化山地生态环境，实现可持续发展。     

Spatial and temporal variations and controlling factors of potential evapotranspiration in China: 1956-2000

Based on the climatic data of 580 stations in China during 1956 and 2000, potential evapotranspiration are calculated using the Penman-Monteith Method recommended by FAO. The spatial and temporal distributions of the potential evapotranspiration over China and the temporal trends of the regional means for 10 major river basins and whole China are analyzed. Through a partial correlation analysis, the major climate factors which affect the temporal change of the potential evapotranspiration are analyzed. Major results are drawn as follows: 1) The seasonal and annual potential evapotranspiration for China as a whole and for most basins show decline tendencies during the past 45 years; for the Songhua River Basin there appears a slightly increasing trend. 2) Consequently, the annual potential evapotranspirations averaged over 1980-2000 are lower than those for the first water resources assessment (1956-1979) in most parts of China. Exceptions are found in some areas of Shandong Peninsula, western and middle basins of the rivers in Southwest China, Ningxia Hui Autonomous Region as well as the source regions of the Yangtze and Yellow rivers, which may have brought about disadvantages to the exploration and utilization of water resources. 3) Generally, sunshine duration, wind speed and relative humidity have greater impact on the potential evapotranspiration than temperature. Decline tendencies of sunshine duration and/or wind speed in the same period appear to be the major causes for the negative trend of the potential evapotranspiration in most areas.     

双目标耦合不确定性模糊模式识别模型

本文在陈守煜建立的模糊模式识别理论的构架基础上,将加权广义距离与模糊熵最小作为模式识别的复合目标函数,建立了考虑随机和模糊不确定性,使目标函数最小的新型模糊模式识别耦合模型。应用此模型对我国12个湖库的富营养化程度进行综合评价,并与原模型的双目标结果进行比较,说明本文建立的模型考虑了不确定性因素的优越性。     

Common-ray tracing and dynamic ray tracing for S waves in a smooth elastic anisotropic medium

Anisotropic common S-wave rays are traced using the averaged Hamiltonian of both S-wave polarizations. They represent very practical reference rays for calculating S waves by means of the coupling ray theory. They eliminate problems with anisotropic-ray-theory ray tracing through some S-wave slowness-surface singularities and also considerably simplify the numerical algorithm of the coupling ray theory for S waves. The equations required for anisotropic-common-ray tracing for S waves in a smooth elastic anisotropic medium, and for corresponding dynamic ray tracing in Cartesian or ray-centred coordinates, are presented. The equations, for the most part generally known, are summarized in a form which represents a complete algorithm suitable for coding and numerical applications.     

Ellipsoidal vertical deflections and ellipsoidal gravity disturbance: Case studies

First, we present three different definitions of the vertical which relate to (i) astronomical longitude and astronomical latitude as spherical coordinates in gravity space, (ii) Gauss surface normal coordinates (also called geodetic coordinates) of type ellipsoidal longitude and ellipsoidal latitude and (iii) Jacobi ellipsoidal coordinates of type spheroidal longitude and spheroidal latitude in geometry space. Up to terms of second order those vertical deflections agree to each other. Vertical deflections and gravity disturbances relate to a reference gravity potential. In order to refer the horizontal and vertical components of the disturbing gravity field to a reference gravity field, which is physically meaningful, we have chosen the Somigliana-Pizzetti gravity potential as well as its gradient. Second, we give a new closed-form representation of Somigliana-Pizzetti gravity, accurate to the sub Nano Gal level. Third, we represent the gravitational disturbing potential in terms of Jacobi ellipsoidal harmonics. As soon as we take reference to a normal potential of Somigliana-Pizzetti type, the ellipsoidal harmonics of degree/order (0,0), (1,0), (1, − 1), (1,1) and (2,0) are eliminated from the gravitational disturbing potential. Fourth, we compute in all detail the gradient of the gravitational disturbing potential, in particular in orthonormal ellipsoidal vector harmonics. Proper weighting functions for orthonormality on the International Reference Ellipsoid are constructed and tabulated. In this way, we finally arrive at an ellipsoidal harmonic representation of vertical deflections and gravity disturbances. Fifth, for an ellipsoidal harmonic Gravity Earth Model (SEGEN: http://www.uni-stuttgart.de/gi/research/paper/coefficients/coefficients.zip) up to degree/order 360/360 we compute the global maps of ellipsoidal vertical deflections and ellipsoidal gravity disturbances which transfer a great amount of geophysical information in a properly chosen equiareal ellipsoidal map projection.     

特殊耦合地震波检测与匹配滤波技术试验研究

针对塔里木盆地沙漠地区提高地震资料分辨率的难度以及制约该问题的关键因素,研究、设计制作了特殊耦合地震波检测系统(SWDS),并利用匹配滤波技术,在不同区块、不同高差的沙丘与不同自然频率的常规耦合检波器接收的信号进行了严格的对比试验。试验结果表明,该项技术对提高沙漠地区地震资料分辨率是有效的。取得了明显的效果。     

地基-非线性结构相互作用空间效应的超谐和亚谐共振研究

建立了考虑空间效应的无质量基础-地基-结构相互作用模型,将模型简化为三个自由度体系,得到了考虑结构水平侧移和扭转位移相耦合的振动方程,用多尺度法研究了体系在强激励下的超谐共振和亚谐共振行为,通过算例分析得到了一些不同于线性体系的结论,为结构非线性分析提供了更深刻的理论依据。