变降深抽水附近地下水非稳定运动的积分方程解

根据完整井变流量抽水附近地下水运动的解析解,利用积分方程的方法,推导出了水井水位降深以任意一种函数关系随时间变化时含水层中地下水非稳定运动积分方程形式的解,并提出了该积分解相应的近似计算方法.最后通过一个实例验证了该方法的实用性.     

卡斯凯迪亚消减带的幕式颤动和滑动：静滑动震颤

发现在最初被认为不活动的北卡斯凯迪亚消减带的深部界面观测到的重复性缓慢滑动事件具有独特的非地震性地震学特征。颤动状的地震信号与用跨越过去6年的地壳运动数据识别出的滑动事件在时间和空间上相关。在滑动事件之间的时段内，颤动活动要么不存在，要么很小。我们称这种颤动和滑动相关现象为幕式颤动和滑动(ETS)。我们认为幕式颤动和滑动的活动可以作为卡斯凯迪亚特大逆冲地震区应力加载的实时指标。     

论非均匀断层滑动弱化速率的标定

尝试用二维断层模型来描述断层在不稳定开始时滑动弱化速率的定标律。断层由一系列受滑动摩擦力作用变弱的片区组成，这些片区被牢固的障碍体所分隔。第一组断层包含不同尺度总滑动长度相同的片区的平均分布，而第二组断层由各种分形康托尔集合组成。破裂的整体活动性质由指数增长率λ来描述。对无限均匀的断层，系数λ由摩擦定律的弱化速率控制。在非均匀断层系中我们估算每一个断层的弱化速率，因为一个断层系的指数增长率λ与均匀断层是一致的。利用这种均匀断层的破裂过程，我们根据不同尺度均匀性断层和给定的系数λ来计算弱片区上的弱化速率。对于大尺度的破裂，弱化速率与尺度无关，长片区的开始过程类似于无限断层的破裂情况。本文考虑的是小尺度和所有不同几何形状的破裂，弱化速率记为α=β0^*／a，其中a为破裂尺度或者单个断层长度的一半，β0^*≈1．158。本文计算了滑动弱化距离Dc的值，在此基础上讨论了计算结果的物理含义，并给出了这个参数与尺度相关的可能解释。     

两种模拟方法(或加温方式)实验结果对比

进行单温阶加温和连续加温两种方式的模拟实验,前者相当于封闭体系,后者相当于开放体系.对比两者的油气产率,并探讨两者与自然界烃源岩生排烃过程之间的关系.实验结果表明,总气体产率和烃气产率开放体系均低于封闭体系;排出油量和总生油率开放体系均大于封闭体系.自然界烃源岩的生排烃过程可能是介于封闭体系和开放体系之间的一种状况.     

The Present Space-Time Motion and Deformation Features of the Northeastern Margin of the Qinghai-Xizang（Tibet） Block and Its Adjacent Area

On the basis of Discontinuous Deformation Analysis (DDA), and considering the moderate intrusion of specific block boundaries to different extents, the first-order block motion model is established for the northeastern margin of Qinghai-Xizang(Tibet) block and the kinematical model for depicting deformation of small regions as well by using GPS observations of three periods (1991, 1999 and 2001). By simulating, we obtained the motion features of the firstorder blocks between the large WWN faults on the sides of the studied region, the distribution features of the principal strain rate field and the inhomogeneous motion features with spacetime of the faults in the northern boundary of the Qinghai-Xizang (Tibet) block.     

A Preliminary Analysis of Relations Between Tectonic Deformation of Sedimentary Cover and Basement in Kuqa Depression

Study of seismic activity in the Kuqa area enables us to infer some possible active faults in basement from the epicentral distribution on different profiles. The relations between active faults in the basement and surface structures are analyzed and the difference between sedimentary cover and basement in their deformation characteristics and the genesis are discussed. The following conclusions have been drawn : ( 1 ) the epicentral distribution indicates that, the east Qiulitag and south and north Qiulitag deep faults in the basement correspond to the east and west Qiulitag anticlines, respectively. Moreover, deep faults also exist beneath the Yiqiklik and Yaken anticlines. It indicates that the formation of surface structures is controlled by deep structures; (2) A NE-trending strike-slip fault develops along the line from the western termination of Yiqiklik structure to Dongqiu Well 5 and a NW-trending active fault on the western side of Baicbeng. The two active faults across the tectonic strike are the main causes for tectonic segmentation of the Kuqa depression and possibly the cause for the middle segment (Kuqa-Baicheng) of the depression to be more shortened than both its eastern and western terminations; (3) The difference between the sedimentary cover and basement in their deformation characteristics depends mainly on the different properties of media between them.The lithospheric strength of the basement in the basin is fairly high, which determines the basement deformation to be mainly of brittle fracture seismic activity. While the strength of sedimentary cover is low, where there exist weak thin layers, such as coal and gyps. Under the effect of strong tectonic compression, the sedimentary rocks may undergo strong viscous or plastic flow deformation; meanwhile, an aseismic detachment may take place along the weak layers.     

浅谈工程建筑物变形监测网的布设

由于受各种条件和因素的影响，工程建筑物及其设备在运营过程中都会产生变形，如建筑物整体或局部发生沉陷、倾斜、位移、扭曲和裂缝等。如果变形在允许范围之内，则认为是正常现象；如果超过了一定的限度，就会影响建筑物的正常使用，严重的还可能危及建筑物的安全。因此，在工程建筑物的施工和运营期间，都必须对它们进行变形观测，以监视建筑物的安全状态，确保安全。     

非静力中尺度模式的现状及发展趋势

随着高性能计算机与大气探测技术的发展 ,使得非静力中尺度数值预报模式的业务化成为可能 ,世界上主要的气象中心最近几年纷纷发展非静力中尺度模式 ,并取得了重要进展 ,这其中尤以英国气象局新发展的非静力通用模式最为突出。基于此 ,介绍了近年来国际上发达国家的非静力中尺度预报模式的现状及发展方向 ,并对该类模式设计中应注意的一些问题进行了阐述     

98.7湖北特大暴雨的天气分析与降水模拟

1998年7月20～23日，湖北省南部发生了一次持续性特大暴雨过程，采用双向嵌套的非静力中尺度数值模式(MM5)对这次强暴雨过程进行初步模拟试验。结果表明，粗、细网格均能较好地模拟出雨带的走向和变动以及武汉地区的暴雨中心，尤其是嵌套域(细网格)模拟的降水强度比粗网格有明显改进，和实际观测结果更接近；另外，对引发这次特大暴雨的对流层低层的中尺度系统也能够很好地模拟出来。