地震与核爆识别的小波包分量比方法

频谱分析法在核爆与地震识别中具有广泛的应用．但是频谱分析方法是稳态方法,即使采用Gabor变换,也因时-频窗口形状不变而分辨串较低．为提高时-频分辨率,本文将小波变换理论用于乌鲁木齐台记录的地震与核爆事件的分析,并提出了识别核爆和天然地震的小波包分量比判据．通过对加拿大黄刀地震台记录的印度地下核爆的分析,进一步验证了小波包分量比判据对核爆和地震的识别具有较高的识别效率．结果表明：对于地震信号,其小波包分量比U03/U1一般都大于1.0,而对于核爆信号,比值U03／U13一般都小于1.0.     

最不利设计地震动研究

实际记录到的真实地震动在工程结构的抗震研究、分析和设计中往往作为一种施加到结构上使结构振动，直至破坏的地震荷载．如何合理选择真实的地震动记录作为研究结构地震反应的输入，一直是国内外抗震研究和设计中引人关注的重要问题．本文首先提出了最不利设计地震动的概念；然后在收集到的国内外5000余条被认为有重要意义的地震动记录基础上，利用综合估计地震动潜在破坏势的方法，对４种场地类型分别给出了长周期、短周期和中周期结构的国内外最不利设计地震动；最后通过几类不同结构的地震反应分析，初步验证了本文所确定的最不利设计地震动的可靠性和合理性．      

RELATIONSHIP OF ECO-ENVIONMENTAL CHANGE WITH NATURAL EROSION AND ARTIFICIALLY ACCELERATED EROSION

Ｆｏｒｌｏｎｇｔｉｍｅ,ｔｈｅｐｒｏｂｌｅｍａｂｏｕｔｎａｔｕｒａｌｅｒｏｓｉｏｎａｎｄａｒｔｉｆｉｃｉａｌｌｙａｃｃｅｌｅｒａｔｅｄｅｒｏｓｉｏｎｉｓｉｎｄｉｓｐｕｔｅ.ＨｉｓｔｏｒｉｃａｌｇｅｏｇｒａｐｈｅｒｓｃｏｎｓｉｄｅｒｔｈａｔｈｕｍａｎｉｎｄｕｃｅｄｅｃｏｅｎｖｉｒｏｎｍｅｎｔａｌｄｅｓｔｒｕｃｔｉｏｎｉｓａｃｃｏｕｎｔａｂｌｅｆｏｒｔｈｅｓｅｖｅｒｅｓｏｉｌｅｒｏｓｉｏｎａｎｄｅｃｏｅｎｖｉｒｏｎｍｅｎｔｄｅｔｅｒｉｏｒａｔｉｏｎｏｎＬｏｅｓｓＰｌａｔｅａｕ[7,8].Ｓｏｍｅｇｅｏｌｏｇ…     

藏西班公湖斑岩铜矿带的形成时代与成矿构造环境

通过对藏西班公湖斑岩铜矿带多不杂和尕尔穷2个大、中型斑岩铜矿床含矿斑岩的研究,初步查明了该铜矿带的形成时代、含矿斑岩性质及成矿构造环境。锆石SHRIMPU-Pb定年结果给出2个铜矿床含矿斑岩的时代分别为127.8Ma±2.6Ma和112.0Ma±2.3Ma,处于造山带演化的碰撞后阶段(班公湖-怒江洋盆的闭合时间为145Ma)。岩石地球化学分析表明,该铜矿带的含矿斑岩属钾玄岩-高钾钙碱性岩系,以富集Rb、K、Sr、Pb等大离子不相容元素和亏损Nb、Ta、Ti等高场强元素为特点,与冈底斯斑岩铜矿带的含矿斑岩相似。所不同的是,班公湖斑岩铜矿带含矿岩浆生成深度较浅,构造环境上处于碰撞后地壳隆升阶段,而冈底斯斑岩铜矿带则处于地壳上升到最大高度后的伸展塌陷阶段。     

Tectonics and Mechanisms of Uplift in the Central Uplift Belt of the Huimin Depression

The Huimin (惠民) depression is a third-level tectonic element of the Bohai (渤海) Bay basin in eastern China. The central uplift belt is the most important oil and gas accumulation zone in the depression, but the lack of adequate geological studies in the area has greatly hindered exploration and development. In this article, using seismic data, fracture mechanics, and a combination of data on fault growth indices and fault throws, we present an analysis of tectonic activity in the central uplift belt and adja...     

西秦岭杨河-固城一带原“泥盆系“中发现早石炭世化石

西秦岭武山杨河礼县固城一带的原"泥盆纪"地层中,发现了大量属于早石炭世的牙形刺、珊瑚和有孔虫化石,为该区地层的重新划分提供了直接的证据.这对于重新认识该区乃至整个西秦岭地区石炭纪古地理格局、地质演化历史、沉积相和沉积环境等都有重要的意义.     

Accelerating Oil and Gas Exploration in Western China by Studies of Formations of Hydrocarbon Accumulations in Superimposed Basins—A Preface

<正>The superimposed basins in the western region of China are a hot research topic for earth scientists home and abroad for their vast area and rich oil and gas resources.Their complex geological conditions and resultant great exploration difficulties have received much attention of the scientists.This issue presents the advances of several scholars in their long-term research on the mechanisms of oil and gas accumulation and the patterns of oil and gas distribution.These studies are part of the National 973 Project entitled Mechanism of Oil and Gas Accumulation and     

应用氢氧同位素方法研究兰州市傍河水源地地下水水体的形成和循环机理

本文通过测定水中氢氧同位素的变化来对兰州市傍河水源地地下水体的形成和循环机理进行分析探讨。分析了兰州市马滩水源地水质恶化的程度,探讨了恶化的原因。对其工作原理及方法作了较详尽的论述。     

Fluid venting from a mud volcano in the Mediterranean Ridge Diapiric Belt

Direct observation of active emission of fluids and mud from a submarine mud volcano were made for the first time in an extensive field of mud diapirs and mud volcanoes on the Mediterranean Ridge using a video camera towed 2 m above the seafloor in 1800 m of water. This recent research using both long range and deep-towed sidescan sonar systems indicates also that diapirism and eruption of mud along the crest of the ridge is more common than previously thought. The southwards increase in age of rock fragments carried within the erupted mud supports the hypothesis that the fluid mud becomes overpressured within a southward-dipping backthrust from the Inner Deformation Front of this accretionary prism.