长江三峡地区沉积层与基底层细结构

叙述长江三峡地区四条地震测深剖面沉积层与基底层速度细结构的研究结果．测区西部的鄂西丘陵地区沉积盖层速度较大，总厚度为 0～3 km，但在秭归盆地南侧与沮水河谷沉积层厚度加大，分别为5.0与4.0 km．测区东部的江汉平原区沉积盖层巨厚，达5～8 km．速度明显偏小．基底面速度在整区达6 km/s以上．在沉积层内部还可细分一层面，在江汉平原区深度达 3～4 km，而在其它地区接近地表．剖面多处为断裂所切割，断裂所经之处不仅速度等值线变化剧烈，且速度值也明显偏低.基底层以速度高并梯度小著称,层内存在三处高速异常区,分别位于黄陵背斜的西、南和东侧．它们是地壳深处玄武岩类高速物质上涌产物，估计这过程发生于黄陵背斜形成之前．由于其活动，造就或影响了基底面剧烈深度变化，以及相应断裂的发育与活动.      

长江中下游铁帽金矿床的物质组份及金的赋存状态

长江中下游铁帽金矿矿石分为四种类型：蜂窝状矿石、松散土状矿石、胶状矿石及块状矿石，前三者金含量较高。主要载金矿物为针铁矿、水针铁矿、赤铁矿、水赤铁矿，铜的次生矿物（铜蓝、蓝铜矿、辉铜矿、孔誉石）、石英以及残留的原生硫化物等，表生金、银矿物以金、银金矿为主，多呈显微金，个别为细粒、中粒金。粒度从原生矿石带→次生金富集带下部→次生金富集带上部有增大的趋势，表生金的成色为828－982，一般为921，大大高于原生带中的金，金、银的赋存状态以吸附状态以独立的金、银矿物两种形式存在，自然金一般呈包体金、粒间金、裂隙金等形式嵌布于载体矿物中。     

白龙江沿岸垂直气候与花椒立体栽植

通过对白龙江沿岸垂直气候分析和花椒生长的实地调查以及栽植试验，将该地花椒的立体种植划分出四个层次。每个层次有其适宜的品种，以期每个层次栽植的花椒尽可能充分利用该层次的气候资源，获得较好的收益。     

长江三峡链子崖,黄腊石地质灾害体场址合成地震地面运动的时程反应

利用长江三峡链子崖、黄腊石地质灾害体周围地区的天然地震记录,对此两地质灾害体的地震危险性进行了分析.应用随机过程理论,计算了两场址的场地地面运动加速度峰值、频谱特征和地震持续时间的人工合成地震加速度时程曲线,以作为两地质灾害体抗震防治的依据.本文的方法也可为重要的建筑结构,如核电厂、海洋平台和超高层建筑的抗震设计提供动力分析所需的人工地震地面运动时程曲线。     

用人工地震波研究三峡地区地面地震动衰减特征

利用长江三峡工程坝区及外围深部构造的人工地震波记录资料,进行了相对速度幅值、速度反应谱和加速度反应谱衰减特征分析,同时利用历史地震资料经转换方法给出的地震动衰减规律进行对比,反映出由人工地震记录地震动参数衰减特征与由历史资料转换确定的地震动衰减特征是有差异的,在不同地质条件的局部地区,这一差异更为明显。这些结果可为缺乏强震记录的地区的地震动估计提供参考。     

Decreasing Reference Evapotranspiration in a Warming Climate—A Case of Changjiang (Yangtze) River Catchment During 1970–2000

This study deals with temporal trends in the Penman-Monteith reference evapotranspiration estimated from standard meteorological observations, observed pan evaporation, and four related meteorological variables during 1970–2000 in the Yangtze River catchment. Relative contributions of the four meteorological variables to changes in the reference evapotranspiration are quantified. The results show that both the reference evapotranspiration and the pan evaporation have significant decreasing trends in the upper, the middle as well as in the whole Changjiang (Yangtze) River catchment at the 5% significance level, while the air temperature shows a significant increasing trend. The decreasing trend detected in the reference evapotranspiration can be attributed to the significant decreasing trends in the net radiation and the wind speed.     

Study on Formation Mechanisms of Heavy Rainfall Within the Meiyu Along the Mid-Lower Yangtze River and Theories and Methods of Their Detection and Prediction

As the project of National Key Basic Research Development Program: Research on Formation Mechanisms and Predictive Theories of Major Weather Disasters in China has been fulfilled by 5-yr efforts of Chinese scientists, achieving results of great significance are as follows: 1) development of multi-scale physical models for Meiyu frontal heavy rainfall based on a range of real-time observations; 2) construction of synoptic models for such heavy rainfall; 3) the Meiyu front found to consist of multi-scale systems that represent a subtropical front, which shears structural features of an extratropical front and ITCZ, displaying sometimes a bi-front feature in the mid-lower Yangtze Basin (MLYB). The positive feedback between pre-frontal wet physical processes and over-front strong convective activities as well as interactions among multi-scale systems of the Meiyu front act as the important mechanism for the maintenance and development of the Meiyu front; 4) proposal of theories and methods for quantitative retrieval of multiple mesoscale torrential rains from satellite remote sensings, leading to a line of products; 5) investigation of applicable theories and techniques for retrieving the heavy rainfall system's 3D structure from dual-Doppler synchronous detectings; and 6) development of a system for meso heavy rainfall numerical prediction models with a 3D variational data assimilation scheme included, a tool that played an active role in flood combating and relief activities over the Huaihe River Basin (HRB) in 2003.     

长江—黄河上游源区沼泽湿地遥感动态特征及其成因分析

通过两个时像的对比解译、调查验证和研究,表明长江-黄河上游源区20世纪90年代初至21世纪初的10年中,沼泽湿地总体呈减少趋势。由于自然和人为综合因素的长期作用,使本区沼泽湿地处于萎缩状态。     

长江三峡地区地球物理异常带地表地质特征

通过长江三峡地区水系发育,航卫片判读,野外地质调查等方面的研究,认为沿长江北西西地物理异常带有地表没有相应的特殊地质构造显示。