Cyclic strength and deformation of crushable carbonate sand     

Masayuki Hyodo  Noritaka Aramaki  Masayuki Itoh  Adrian F.L. Hyde 《Soil Dynamics and Earthquake Engineering》1996,15(5):331-336

Cyclic triaxial tests have been carried out on a skeletal carbonate sand from the west coast of Eire. Results are presented for undrained cyclic shear tests on samples with 80% of relative density consolidated under both isotropic and anisotropic conditions. Failure was defined as a 5% double amplitude cyclic strain and a 5% peak axial strain for stress-reversal and non-reversal stress conditions, respectively. Using this definition the cyclic strength for isotropically consolidated samples was affected by the confining pressure although the angular platey nature of the sand resulted in higher cyclic strengths than for a comparable silica sand. For anisotropically consolidated samples the cyclic strength increased with increasing initial static shear stress while on the other hand the cyclic strength normalised in the usual way with respect to the initial confining pressure decreased as this pressure increased.  相似文献   

1988年反厄尼诺(La Niña)事件的数值模拟     

张荣华 《气象学报》1996,54(1):53-64

用中国科学院大气物理研究所高分辨率、自由表面热带海洋环流模式对厄尼诺/南方涛动(El/Southern Oscillation)循环中另一重要位相La Niña事件进行了数值模拟研究。模式区域为南北纬30°之间的热带太平洋,经纬圈水平方向分辨率分别为2°和1°,垂直方向分为不等距的14层;模式中考虑了盐度并引入与洋流切变和层结稳定度有关的垂直扩散参数化方案。在观测到的海表风应力、热量和淡水通量(蒸发与降水之差)驱动下,所发展的模式从1984年积分到1989年。本文给出模式对近十几年来最强的1988年La Niña事件进行数值模拟的结果,着重分析La Niña期间热带太平洋海面起伏、流场和温度场时空演变,以及La Niña和El期间变量场时空结构差别。文中还进行了模式结果和一些观测资料间的比较。  相似文献   

图象恢复在工业CT中的应用   总被引：1，自引：0，他引：1  

顾本立  葛云 《CT理论与应用研究》1996,5(4):1-5

对于以影象增强器为检测系统的目标旋转式工业ＣＴ，分析了其图象退化的因素，采用对一维投影数据进行图象恢复的方法来提高ＣＴ图象质量。文中给出图象恢复公式，从计算机模拟和实验图象恢复的结果可看到所用方法提高了图象清晰度。  相似文献   

大同盆地内砂板梁上断裂新活动及其力学实验模拟   总被引：2，自引：2，他引：2       下载免费PDF全文

董文忠  侯建军 《地震地质》1996,18(1):75-82

通过野外实地考察、野外现场力学实验及室内力学实验模拟断裂的新活动，来研究砂板梁新隆起的活动构造特征和类型。旨在从实验模拟与野外实践相结合的基础上，对活动构造，特别是对断裂新活动在第四纪松散沉积层中特殊的表现形式进行研究，寻找第四纪松散沉积层中断裂新活动的有效识别标志，这是准确判定断裂新活动的关键，对工程地质评价及区域性地震危险性分析有很好的实用价值  相似文献   

The manufacture of a three-dimensional transducer used in laboratory     

刘晓红 《地震学报(英文版)》1996,9(2):345-349

Ｔｈｅｍａｎｕｆａｃｔｕｒｅｏｆａｔｈｒｅｅ－ｄｉｍｅｎｓｉｏｎａｌｔｒａｎｓｄｕｃｅｒｕｓｅｄｉｎｌａｂｏｒａｔｏｒｙＸＩＡＯ－ＨＯＮＧＬＩＵ（刘晓红）（ＩｎｓｔｉｔｕｔｅｏｆＧｅｏｐｈｙｓｉｃｓ，ＳｔａｔｅＳｅｉｓｍｏｌｏｇｉｃａｌＢｕｒｅａｕ，...  相似文献   

地震构造活动的模拟试验     

王非  郑铁民 《地震研究》1996,19(4):371-376

本在活动构造考察及研究的基础上，采用先进的精密仪器仪表，在模拟试验中自控制监测构造活动情况，深入研究地震前后的断裂运行特征及其与地震的关系，这对圈定地震危险区和判定可能发生强震的破裂段，为国民经济建设提供可靠的依据，对逐步实现地震预报，最大限度地减轻地震灾害，均具有重要实际的意义  相似文献   

NUMERICAL SIMULATIONS OF HEATING ANOMALY EFFECTS OF TIBETAN PLATEAU ON CIRCULATION IN SUMMER          下载免费PDF全文

Qian Yongfu  Liu Xiaodong  Zhong Zhong 《Acta Meteorologica Sinica》1992,6(1):70-81

A 5-layer numerical model with p-σ incorporated coordinate system and primitive equations is used to simulatethe effects of heating anomaly at and over the Tibetan(Qinghai-Xizang)Plateau on the circulations in East Asia in sum-mer,The model is described briefly in the text and the results are analysed in somewhat detail.Results show that the sur-face albedo,the drag coefficient,the evaporation rate and the ground temperature all have large influences on the circula-tion near the Plateau and in East Asia.When the heating at the surface increases,the Tibetan high in the uppertroposphere intensifies,too.Its area enlarges and its axis tilts to northwest.The upper tropical easterly increase andshifts to north.The southwesterly in the lower troposphere,in consistence,also increases.The cross-equatorial low-lev-el currents along Somali and South India are influenced to increase their speeds while those over North Australia de-crease.The land low over the Asian Continent deepens.Meanwhile the upward motions over the land of east China andover the Indo-China Peninsula intensify and therefore the precipitation over those areas increases.However,along thecoastal area of China the upward motions and therefore the precipitation decrease.Atmospheric heat source anomaly has large influence on the circulation,too.Simulated results indicate that heatsource anomaly in the lower atmosphere over the Plateau influences the intensity and the position of the monsoon circu-lation while that in the upper atmosphere only affects the intensity.The heating status over the Plateau has slight influ-ence on the westerly jet,north of the Plateau,while it has strong effect on the subtropical jet at the mid and low latitudes.  相似文献   

南京地区葡萄生长发育模拟,品质分析和对策   总被引：2，自引：0，他引：2  

王生明  郭爱民 《南京气象学院学报》1992,15(4):566-573

  相似文献   

农田土壤水分预测模型应用研究   总被引：10，自引：0，他引：10  

申双和  周英 《南京气象学院学报》1992,15(4):540-549

  相似文献   

强对流天气发生前期地面风场特征   总被引：5，自引：1，他引：5  

翟国庆  俞樟孝 《大气科学》1992,16(5):522-529

根据对华东地区9次强对流天气的地面风场分析发现,强对流的发生发展与锋前暖区的中尺度辐合线有密切关系,与地面中尺度辐合线相伴的扰动辐合值为-0.8×10~(-4)·s~(-1)左右.当有移动的天气系统与其相遇时,交点附近扰动辐合值迅速增大,促使对流迅猛发展且移速加快.辐合线的形成与大尺度背景和特定地形有关.移动的中尺度辐合线与变压风有关而静正辐合线常与露点锋相伴.  相似文献