三河-平谷8.0级地震区浅层三维密度结构反演研究

为研究三河-平谷地震区浅层构造背景、地震孕育机理及地震与构造的关系,利用高精度重力异常数据,采用基于块体生长模式的重力三维反演算法对地震区浅层三维密度结构进行反演,并通过模拟试算验证基于块体生长模式反演方法的有效性和稳定性。高精度布格重力异常显示,三河-平谷8.0级地震位于大兴重力局部高、三河-马坊重力局部高与大厂重力低之间的交汇过渡低值区域。研究区浅层三维密度结构反演结果表明,1679年三河-平谷M8.0地震明显受NE向夏垫断裂控制,断裂两侧密度差异明显且向下延伸约10 km,推测发震部位深约10 km。     

场地地震效应及其预测的某些考虑

本文从场地地震危险性评价,地震危险性概率分析、场地地震工程地质单元划分、地震反应分析、活断层工程分类等五个方面、论述场地地震效应及其预测中基本原理和方法。根据工程地震危险性评价和分析、地震小区划等地震工程实践,对场地地震效应及其预测提供一些基本考虑和经验     

苏、浙、皖地区沉积-大地构造演化

中国南部近东西延伸的扬子板块形成于距今800Ma 前。自震旦纪开始,在其东缘苏、浙、皖地区形成了两个呈北东东向展布的并在其东端相联的裂陷槽。其沉积厚度达万米。沉积演化晚期形成了复理石与磨拉石。复理石堆积于晚奥陶世,此时裂陷槽为两个向东开口的海湾,碎屑物来自盆地南北两侧的扬子古陆。磨拉石堆积的时代从晚奥陶世末到中泥盆世,碎屑物     

南极乔治王岛环境质量现状调查

本文以１９９２／１９９３年度中国第九次南极考察期间对南极乔治王岛的表土、地衣、苔藓等样品的分析资料为基础，研究探讨了８种无机重金属元素、５种有机污染物的浓度水平。其结果表明，重金属在三种环境样品中的含量分布存在着明显的差异；地衣、苔藓两种植物呈现对不同重金属元素的不同富集能力；∑６６６、∑ＤＤＴ和ＰＣＢｓ及油的沾污亦很明显。本文还对污染物质的来源、南极环境样品历次调查分析的结果以及世界部分地区的背景水平进行了讨论和比较     

Physical,chemical, and biological conditions associated with the early stages of the Lake Michigan vernal thermal front

An investigation of the thermal front in southeastern Lake Michigan during April 1988 revealed a dynamic physical, chemical, and biological environment. The front was observed approximately 4 km from the coast as a distinct gradient separating cold open-lake waters from warmer nearshore waters. Surface isotherms near the front were generally parallel to one another but skewed with respect to shore. Comparison between April 22 and 29 showed that the surface isothern pattern was modulated by wind stress. The pattern from April 29 showed signs of flow instabilities with horizontal scales of 1 km to 5 km. Surface drifter trajectories provided estimates of horizontal convergence at the fron which varied from 7×10^?6 s^?1 to 20×10^?6 s^?1. Inferred rates of downwelling, which ranged from 9.5 m d^?1 to 20.7 m d^?1, were sufficient to move a water parcel from the surface to the bottom in 2 to 6 d at the front. Convergent circulation was observed on both sampling dates despite contrasts in wind stress. Concentrations of chloride, soluble silica, and chlorophyll, which were always higher inshore, were 5% to 82% larger than offshore mean values. The aquatic environment just inshore of the thermal front was characterized by chlorphyll concentrations which exceeded 5.0 μg 1^?1 while concentrations offshore were between 1.0 μg 1^?1 and 2.0 μg 1^?1. A relatively uniform vertical structure in chlorophyll concentrations in the frontal zone was consistent with the observed convergence and inferred downwelling near the front.     

深井水位降水效率随测层深度的变化规律模拟

统计鲁北平原４井降水效率表明，地质类型相同的深井水位降水效率主要受控于测层埋深；规律性级强，笔者在统计基础上建立了模拟公式，并计算了不同深度测层的降水效率，与实际统计弥合度极好，笔者认为“对类型相同不同深度测层水位降水干扰排除过程中即可利用该式对其效率直接计算，免去了统计，修定的麻烦。     

储层毛细管压力曲线在东海油气储量计算中的应用

本文阐述了利用储层毛细管压力曲线计算含油炮和度的方法,该方法在东海油气储量计算中取得良好的结果。     

Collision and thermal history of Indian-Sundaland-Eurasian plates as implicated by40Ar/39Ar age spectra of granodiorites

⁴⁰Ar/³⁹Ar plateau ages of biotite, plagioclase, K-feldspar and hornblende from the Biluoxueshan and Lincang plutons in the three-river area of Yunnan and the Quxu pluton in the Gandise belt of Xizang indicate that the three plutons were emplaced at 420, 234 and 43.4 Ma, respectively. Based on the study of closure temperatures and thermal histories, it is shown that the Lincang and Biluoxueshan plutons experienced the same thermodynamic event during 85–90 Ma, temporally representing the collision between the Sundaland and Eurasian plates, and that the Quxu pluton was uplifted at a much faster rate during 40–44 Ma(2.6 mm/a), marking the collision between the Indian and Eurasian plates.     

地面中—β尺度强锋区激发的特大暴雨过程分析

受0012号台风（派比安）外围影响，2000年8月30日02时至31日08时，在江苏省东北部发生了一次具有局域性、突发性、高强度、超历史、灾情重等特征的特大暴雨，分析研究发现，在台风外围第二象限，江苏东北部地面存在中-β尺度的能量锋区，此能量锋区是构成产生、维持特大暴雨的中-β尺度的天气系统。利用锋生函数对此能量锋区的发生发展进行诊断，结果表明，锋生函数的变形项起了决定性作用，辐合项也有较明显的贡献，非绝热加热在锋生初期有作用，但对锋区的维持，其贡献并不明显，进一步用二维中尺度方程对锋区进行数值模拟，结果显示，在能量锋附近驱动产生了涡旋，在涡旋上升支，将高能区的暖湿空气向上输送而成云致雨，在涡旋下沉支，通过下沉气流使雨迅速下落，同时拖曳冷空气使地面降温，使得锋区维持和加强，致使雨强增幅，综合分析表明，中-β尺度能量锋区形成以后，通过锋区附近的中-β尺度的辐合线，中低压，中高压以及锋区附近驱动的扰动涡旋等中-β尺度的天气系统间的相互作用，导致了这次江苏省东北部高强度的特大暴雨。