依靠技术创新将四川的资源优势转化为经济优势

四川是一个矿产资源大省,经过５０年的发展,四川的矿产资源格局可划分为五大矿产资源经济区。但是四川质优的富矿少,原矿组分复杂,矿产业利润薄。因此要将四川的矿产资源优势转化为经济优势必充分依靠技术创新,并以优势矿种黄金开发,稀土资源开发利用,川南煤、硫和高岭土资源的开发利用,非金属矿的开发利用为重点坑技术示范,带动全川矿产业的发展。     

西部山区总辐射气候学计算及分布

根据西部山区太阳总辐射的实测资料分析，指出，西部山区总辐射的气候学计算必须考虑日照，水汽分布及海拔高度的影响。为此研制了适宜于西部山区的总辐射气候学计算公式Ｑ＝Ｑ０（ａ＋ｂｓ１＋ｃｓ１＾２），进而讨论了西部山区总辐射的时，空分布。     

基于连通性指数(IC)的近30年鄱阳湖流域水系结构与水文连通演变评估

由于气候变化和人类活动等多重影响,流域河湖水系格局与连通程度发生了显著变化,进而引发洪涝灾害等一系列水资源问题。本文以鄱阳湖流域为研究区,基于Google Earth Engine(GEE)提取1989—2020年5期水系数据,采用图论方法构建水系评价体系,定量分析该地区近30年来水系格局和结构连通性的时空演变特征,并结合该时期地形、土地利用和归一化植被指数(NDVI)等数据,利用连通性指数(index of connectivity,IC)评估功能连通性的动态变化,进而探讨水文连通与径流量和输沙量的联系。结果表明,近30年来鄱阳湖流域水系结构趋于复杂化,主要体现在流域北部。除干流外,其他等级河流的数量和长度均有所增加,其中Ⅲ级河流最为明显。河网密度、水面率、河网复杂度和发育系数均呈增加趋势,2000年后的变化率约为2000年前的两倍。水系连通环度、节点连接率和水系连通度总体增加,结构连通性呈好转趋势且变化幅度较小。功能连通分析表明,近30年来大部分流域IC减少,流域下游靠近主河道的平坦地区IC较高,上游远离河道的植被密集区域IC较低。此外,IC与年径流量和输沙量表现为显著的正相关性(...     

敦煌壁画计算机存贮与管理信息系统研究

该研究以０４５号窟为例，应用近景摄影测量、数字图象处理、色度学和信息系统理论和技术方法，以现有的仪器设备为基础，对洞窟内壁画、塑象等进行近景摄影测量、图象几何纠正和彩色失真矫正，建立了可操作的“敦煌壁柬计算机存贮与管理信息系统”。为敦煌英高窟壁画、逆象等文物图象数据永久保存、修复、还原和进一步开发研究等提供服务。     

无限饱水孔隙弹性空间中由运动源所产生的位移场

基于Ｂｉｏｔ的饱和孔隙弹性介质的运动方程和利用复变函数方法，本文研究了无限饱水孔隙弹性空间中由常速运动源所产生的位移场。考虑了两种类型源：ａ．沿无限空间水平轴运动的斜向集中力源；ｂ．运动双力偶源。关于力源的运动速度，考虑了４种情形：ａ．力源的运动速度Ｕ小于饱水孔隙弹性介质的三种体波速度一亚音速情形；ｂ．速度Ｕ小于介质的第一纵波过度和横波速度，但大于第二纵波速度─—弱跨音速情形；ｃ．速度Ｕ小于第一纵波速度，但大于横波速度和第二级波速度─—强跨音速情形；ｄ．速度Ｕ大于介质的所有三种体波速度─—超音速情形。结果表明，在跨音达和超音速情形里，解呈现出与力源相联系的平面冲击波特征，位移出现了相应的跳跃。     

东营凹陷沙河街组层序地层及地层格架研究

本文依据层序地层学的基本原理，从沉积层序、生物地层、测井曲线和地震层序分析入手，对东营凹陷沙河街组进行层序地层划分，划出二个层序，并确立其地层格架。     

Comparison of metal(loid) concentrations in water, sediments and fish from two large shallow lakes

Hulun Lake and Taihu Lake are both large shallow lakes in China. In summer and winter of 2009, water, sediments and fish samples were collected from the two lakes and the concentrations of metal(loids) were analyzed. The results demonstrated that aqueous concentrations of arsenic (As), chromium (Cr), cadmium (Cd), nickel (Ni) and copper (Cu) in Hulun Lake were significantly higher than those in Taihu Lake. Especially, the As concentrations (about 130 μg/L) in Hulun Lake dramatically exceeded the permissible level of drinking water. Compared with Taihu Lake, metal(loid) concentrations in the sediments of Hulun Lake were significantly lower, which might have less impacts on the metal exchanges between water and sediments. In contrast, concentrations of the measured metal(loids) (including As) in fish from Hulun Lake and Taihu Lake were comparable, suggesting that the dramatic difference in aqueous and sediment metal(loid) concentrations had less influence on the metal(loid) bioavailability. The higher concentrations of dissolved organic carbon (DOC) and cations (e.g., Na⁺, K⁺ and Mg²⁺) in lake water might contribute to the reduced metal(loid) bioavailability to fish in Hulun Lake.     

New developments on existence and uniqueness of solutions to some models in atmospheric dynamics

This survey is concerned with the new developments on existence and uniqueness of solutions of some basic mod-els in atmospheric dynamics, such as two-and three-dimensional quasi-geostrophic models and three-dimensional balanced model. The main aim of this paper is to introduce some results about the global and local (with respect to time) existence of solutions given by the authors in recent years, but others' important contributions and the literature on this subject are also quoted. We discuss briefly the relationships among the existence and uniqueness, physical in-stability and computational instability. In the appendixes, some key mathematical techniques in obtaining our results are presented, which are of vital importance to other problems in geophysical fluid dynamics as well.     

科技英语写作中的常见标点符号与数字表示疏误

针对目前科技英语出版物中常见的标点符号和数字疏误，指出撰稿时应该注意的问题。     

Sedimentary evidence for recent eutrophication in the northern basin of Lake Taihu,China: human impacts on a large shallow lake

Environmental change in Lake Taihu and its catchment since the early to middle part of the twentieth century has left a clear geochemical record in the lake sediments. The human activities in the lake and its catchment responsible for the change include agriculture, fishery, urbanisation, sewage and industrial waster disposal. Sediment cores were collected from Meilian Bay of northern Lake Taihu to investigate the record of anthropogenic impacts on the lake’s ecosystem and to assess its natural, pre-eutrophication baseline state. Two marked stratigraphic sediment units were identified on the basis of total phosphorus concentration (TP), pigments, total organic carbon (TOC)/total nitrogen (TN), δ¹³C and δ¹⁵N corresponding to stages in the lake history dominated by phytoplankton, and by aquatic macrophytes. Results show that as TP loading increased from the early 1950s the lake produced sediments with increasing amounts of organic matter derived from phytoplankton. In the early 1950s, the first evidence for eutrophication at the Meilian Bay site is recorded by an increase in C/N values and in sediment accumulation rate, but there is little change in phosphorus concentrations, pigments, δ¹³C and δ¹⁵N at this time. After 1990 a more rapid increase in trophic status took place indicated by increased levels of phosphorus, pigments, δ¹⁵N and by decreased δ¹³C and TOC/TN values in the lake sediments. The first increase in trophic status of the early 1950s results mainly from agricultural development in the catchment. In contrast, the acceleration from ca. 1990 originates from the recent development of fisheries and the urbanisation and industrialisation of the catchment.