温度场和渗流场耦合对恐龙化石风化破坏的影响

在恐龙化石经受风化破坏过程中,温度和水是起作用的两大主要因素。为了深入探讨恐龙化石风化破坏机理,有效、科学、合理地保护恐龙化石,该文将恐龙化石及围岩作为岩体,运用岩体水力学研究中温度场与渗流场之间的耦合关系,研究温度和水在恐龙化石风化破坏过程中的内在机制。通过建立温度场与渗流场数值模型,模拟温度场与渗流场在恐龙化石风化过程中的相互作用,定性分析了温度与水相互作用对化石风化的破坏机理。     

Geophones on blocks: a prototype towable geophone system for shallow land seismic investigations

In recent years some authors have given a certain amount of attention to towed seismic reflection acquisition systems. Based on some of these works we sought to design and test a system making use of currently available geophones instead of specifically designed sensors as employed in some previous works. Thus, bearing in mind that the geophone's characteristics are achieved in the conditions that they are originally designed to be employed in, i.e., coupled with a spike driven into the ground, we devoted our attention to some of the variables involved in the geophone's performance, namely the total weight, the effect of a spikeless geophone and the surfaces on which the geophone is placed. Previously, we had experimentally verified some variations in the signal response due to coupling geophones in different surface materials, such as hard soil, asphalt and concrete pavement and we noticed that these surface materials were in fact an important factor in the overall response. Hence, these materials, or as we also called them coupling agents, could be employed as a base material in the construction of a mobile seismic acquisition device composed of blocks of a certain size, on which the geophone would be then inserted and thus making it into a spikeless surface towable system. Therefore, various materials were tested in order to select one that could maintain a similar fidelity to that of the spike coupled geophone and thus contribute towards building a more time efficient and towable geophone and block system. Pinging tests revealed variations in the coupling frequency and damping characteristics of each coupling agent and from all of these tested materials one was selected for field comparative tests with the normally planted geophones with spike coupling. Finally a seismic reflection profile was acquired simultaneously with both systems, i.e., spike coupling versus cement block coupled geophones. This field test showed similar results in terms of signal levels and frequency content and therefore it was possible to observe the presence of the same reflectors and other seismic events in either of the time sections. With this experiment we propose not only a system that allows a time efficient seismic field operation but we also aim to encourage more research into the response dependency of the coupling agent of which the towable base block is made of.     

储液罐地震安全问题研究综述

储液罐的地震安全问题主要涉及到抗震设防水准的确定和储液罐本身的抗震设计.本文简要介绍了储液罐的震害现象及机理,对比分析了中国、美国、欧洲等国家有关储液罐抗震设防水准,并阐述了国内外学者在储液罐抗震计算方面所做的工作及获得的成果,同时还指出了存在的问题和今后研究工作的发展趋势.     

珠三角地区晚第四纪以来气候变化和海平面升降的耦合效应——兼论珠江三角洲盆地及其周缘断裂的活动性

珠江三角洲第四纪地层可划分为三个沉积旋回,分别对应于三次海水进退旋回和三次气候暖冷交替旋回;三角洲盆地边界及其内部的分割性断裂构造有同沉积活动属性,地表探测难以找出其活动的直接地质依据;本区晚更新世晚期地层的古气候记录暗示,地球演化本身正在使现今气温逐渐升高,其力量远超过人类的影响。     

邢台地震区浅部构造特征及其与深部构造的耦合关系

根据邢台7-2 级和6-8 级地震震中区的浅层和超浅层地震勘探结果,查明了震中区浅部铲形断裂的性质及活动年代,认为新河断裂(F1) 自晚更新世以来已不再活动,它不是发震断裂。另外,结合该区深地震反射剖面和深地震测深剖面结果,讨论了震中区的深浅部构造形态及它们的相互关系,从而确定了发震断裂应为震源之下的高倾角超壳断裂①。邢台地震的发生是由于地幔岩浆的上侵作用产生附加应力场,并与区域构造应力场共同作用使该断裂重新活动,引发了邢台地震,并引起浅部断层及地表物质的运动     

大气水文模式耦合研究综述

首先阐明大气水文模式耦合的必要性,总结作为二者耦合的共同界面——陆面模式的发展过程。在此基础上,从耦合研究方法和目的出发,分4个类别详细论述当前国内外大气水文模式耦合研究的现状。指出了单向耦合不足和进行双向耦合所面临的几个关键问题包括：尺度问题、次网格分布非均匀性、降水模拟等。未来要求充分利用“3S”、四维变分同化等新技术和新方法,加强多学科的联合研究,深入开展大气水文模式的双向耦合试验和敏感性分析,研究大气—植被—土壤—水文系统的交互影响,从根本上提高大气和水文模式的模拟和预报水平。     

年代际气候预测系统IAP DecPreS的海洋同化试验在西北太平洋的海温偏差及其对亚洲夏季风的影响

本文分析了中国科学院大气物理研究所年代际气候预测系统IAP DecPreS的海洋同化试验（简称EnOI-IAU试验）在西北太平洋地区的海表面温度（SST）年循环的模拟技巧,并通过对比IAP DecPreS系统自由耦合历史气候模拟试验结果,在包含海气耦合过程的框架下讨论了耦合模式中西北太平洋夏季SST模拟差异,及其对亚洲季风区夏季季风降水模拟的影响。结果表明,EnOI-IAU试验较好地模拟出了西北太平洋各个季节的SST空间分布,并显著减小了原存在于历史气候模拟试验中持续全年的SST冷偏差。混合层热收支诊断分析表明,包含同化过程在内的海洋过程的模拟差异对西北太平洋海温的模拟提升有重要贡献。夏季,EnOI-IAU试验模拟的印度季风伴随的低层西风较观测偏东、偏强,且高估了赤道西太平洋区域的降水量值、低估了印度洋区域的降水量值。水汽收支分析显示,气旋式环流异常造成的水汽辐合异常是造成亚洲季风区降水模拟差异的主要原因。研究表明,较之历史模拟试验,EnOI-IAU试验中夏季西北太平洋地区SST增暖造成局地对流增强,进而使得局地产生异常上升运动,水汽辐合增强,造成西北太平洋地区降水模拟偏多,激发出低层西风异常及赤道外气旋式环流异常。该低层西风异常导致了北印度洋地区低层辐散异常,减小了原存在于历史试验中印度洋地区的正降水偏差。西北太平洋气旋式环流异常一方面增强了印度夏季风伴随的低层西风,使得更多的水汽从阿拉伯海输送到西太平洋暖池区域,增强了该区域的降水量;另一方面,该气旋式环流异常减小了历史模拟试验中中国南部区域偏强的低层风速,进而提升了模式对东亚低层西南风的模拟能力。     

渤海湾盆地大歧口凹陷断裂系统与陆内拉分断陷

大歧口凹陷位于渤海湾盆地中部,是在中生代构造基础上形成的新生代构造单元,是我国最具勘探价值的大型富油气凹陷。前人对大歧口凹陷盆地结构、断裂构造、演化特征方面有了较为深入的研究,但对凹陷内主要断裂的分段活动特征、构造迁移,以及新生代基底走滑-盖层伸展构造体系的深浅部耦合关系并未进行全面细致的研究,这在一定程度上限制了对凹陷内断裂活动特征、构造成因机制、断裂拓展演化规律详细的构造分析。本文在精细解释、深入分析地球物理资料的基础上,开展了详细的构造研究。研究表明,歧口凹陷充填格局主控断裂为东西走向,近南北向的沿岸变换带是主变换带;新生代的构造体系受北东向右行基底走滑断裂和东西向的盖层伸展构造的双重控制,并形成三级断阶带。基底-盖层断裂的耦合方式主要有两种:一是在盖层中形成强制性褶皱传递基底走滑,二是在盖层中形成一系列雁列式正断层。欧亚板块下的地幔物质在印度板块和太平洋板块两大构造系统的共同作用下,自南向北迁移并上涌,导致歧口凹陷主要断裂的规模、活动期以及断裂活动由南西向北东迁移、演化。     

云南保山黑山金异常查证

开展1/1万土壤剖面测量时圈定金异常,进而在地表发现一定规模的构造破碎带蚀变岩型铜金矿(化)体,经激电偶极测深认为黑山金异常具有较好的找矿前景。钻孔验证正在进行中。     

Source Inition Pattern and Coupling Mechanism of Granular Deposit and Seepage in Steep Longitudinal Gully,Wenchuan

Generally, collapse and landslide are the main sources of granular deposits while the initiation of deposits is triggered by the tremendous runoff from steep longitudinal gully. Substance composition, topographic condition and catchment characteristics directly affect the models of deposits initiation, and larger longitudinal grade provides better topographic condition for the initiation. Several sets of experiments on model casing were designed to simulate the failure mode of slopes under the states of stable and unstable seepages according to catchment and penetration characteristics. It was revealed from the experiments that the initiation of granular deposits had two fundamental modes, that is, fire hose effect and static liquefaction. The former one generally happens at the unsaturated slope or the slope of high permeability while the latter case occurs at the soils containing fine particles. It was concluded that the fire hose effect could generate the deep and narrow eroded channel along with the runoff, the movement distance was related to the continuous hydrodynamic force, and the transporting capacity of solid substances was weak. In addition, slope fluidization was featured with slow seepage failure at the early stage, instantaneous shear failure at the late stage, and wider channel came out due to serious erosion.