泾河下游古洪水滞流沉积物地球化学特征研究

通过沿泾河河谷广泛的野外考察,在高陵县杨官寨段发现典型的全新世黄土-土壤剖面。经过详细观测、系统采样和化学元素、粒度成分和磁化率等多指标测定,从剖面鉴别出两组古洪水滞流沉积层（SWD）,分别记录了发生在4 200 ~ 4 000 a B.P.和3200 ~ 2800 a B.P.期间的特大洪水事件。该研究着重对古洪水滞流沉积层与黄土层和古土壤层的元素地球化学特征进行对比研究。结果表明:（1）在风成沉积物中,Fe2O3、Al2O3、K2O、MgO等元素含量在古土壤层高于黄土层,而CaO和Na2O元素含量则表现出相反的变化。表明风化成壤过程中,这些元素的迁移变化受到全新世以来气候变化和成壤作用的影响。而Zr、Hf、Ti、Cr、Y、Th等微量元素含量与地壳平均丰度相当,且变化甚微。这是由于这些微量元素主要包含在粗颗粒和重矿物之中,其化学性质比较稳定,具有强抗风化性,很少受到风化成壤作用的影响。（2）单个古洪水滞流沉积层,是洪水悬移质泥沙在高水位滞流环境中沉积形成的,分选性很好,故其底部多粗颗粒和重矿物沉积,Zr、Hf、Ti、Cr、Y、Th等微量元素含量呈现突出的尖峰;自下向上随着颗粒逐渐变细,粘粒成分增加,Fe2O3、Al2O3、K2O、MgO等元素含量出现高峰。这两类元素由下向上的相互消长关系,与沙级颗粒含量和磁化率值变化规律对应,反映出古洪水滞流沉积层的基本理化特性。这个研究成果对于完善古洪水沉积学和水文学的方法和理论具有重要的科学价值。     

中国西北地区气溶胶的三维分布特征及其成因

利用CALIPSO卫星遥感资料研究中国西北地区气溶胶的三维分布,分区域按类别讨论气溶胶的出现频率和气溶胶光学厚度(AOD),并在此基础上,结合MERRA-2再分析数据探讨形成原因.结果表明:中国西北地区气溶胶含量较高,以沙尘和污染性沙尘为主,主要分布在塔克拉玛干沙漠、古尔班通古特沙漠和甘肃-内蒙古一带.气溶胶的出现频率...     

天然气的测井勘探与评价技术

天然气在我国新世纪能源战略中占重要地位,但目前其总体勘探程度较低.测井是一种非常重要而有效的天然气勘探手段,本文旨在对如何利用测井方法识别和评价天然气进行系统总结、分析和展望.在对天然气的测井响应特点和其岩石物理基础进行简单总结说明的基础上,对基于测井的天然气定性识别和定量评价技术进行了归纳、总结和分析,并对中深部天然气层的测井响应特点及其识别、评价方法以及测井新技术在天然气勘探中的应用进行了分析和展望,最后对天然气勘探中的基础研究、测井系列选择、多学科结合等方面给出了笔者简单的看法.     

烟台市自来水管理信息系统的设计与实践

结合烟台市自来水管理实际,介绍了基于ArcGIS的烟台市自来水管理信息系统的设计方案,阐述了系统开发平台、设计思路、系统设计流程和系统功能,着重说明了用户与技术人员交互性扩展系统功能的构想。     

综合自然地理研究有关问题的探讨

该文从进一步完善综合自然地理研究的角度出发,就与综合自然地理研究有关的几个问题如综合自然地理学的研究对象,综合研究的内涵,区域综合研究以及综合自然地理研究成果的应用作了剖析.     

Optimal Gridding Process for GMI Brightness Temperature Using the Backus-Gilbert Method

Satellite microwave instruments have different field of views (FOVs) in different channels. A direct average technique ("direct method") is frequently used to generate gridded datasets in the earth science community. A large FOV will measure radiance from outside the area of a designated grid cell. Thus, the direct method will lead to errors in a measurement over a grid cell because some pixels covering areas outside of the cell are involved in the averaging process. The Backus-Gilbert method (BG method) is proposed and demonstrated to minimize those uncertainties. Three sampling resolutions (6.5 km × 6.0 km, 11.5 km × 6.0 km, 13.0 km × 6.0 km) are analyzed based on the scanning characteristics of the Global Precipitation Measurement (GPM) Microwave Imager (GMI) 18.9-GHz channel. Brightness temperatures (TBs) at 0.5 km × 0.5 km resolution over eastern China are used to obtain synthetic 18.9-GHz TBs at the three sampling resolutions. The direct and BG methods are both applied to create a 25 km × 25 km gridded dataset and their related uncertainties are analyzed. Results indicate the error variances with the direct method are 3.00, 3.68 and 4.99 K2 at the three sampling resolutions, respectively. By contrast, the BG method leads to a much smaller error variance than the direct method, especially over areas with a large TB gradient. Two GMI orbital measurements are applied to verify the BG method for gridding process is reliable. The BG method could be utilized for general purpose of creating a gridded dataset.     

A divide-and-conquer method for space–time series prediction

Space–time series can be partitioned into space–time smooth and space–time rough, which represent different scale characteristics. However, most existing methods for space–time series prediction directly address space–time series as a whole and do not consider the interaction between space–time smooth and space–time rough in the process of prediction. This will possibly affect the accuracy of space–time series prediction, because the interaction between these two components (i.e., space–time smooth and space–time rough) may cause one of them as dominant component, thus weakening the behavior of the other. Therefore, a divide-and-conquer method for space–time prediction is proposed in this paper. First, the observational fine-grained data are decomposed into two components: coarse-grained data and the residual terms of fine-grained data. These two components are then modeled, respectively. Finally, the predicted values of the fine-grained data are obtained by integrating the predicted values of the coarse-grained data with the residual terms. The experimental results of two groups of different space–time series demonstrated the effectiveness of the divide-and-conquer method.     

Climatological characteristics of summer precipitation over East Asia measured by TRMM PR: A review

Precipitation is an important indicator of climate change and a critical process in the hydrological cycle, on both the global and regional scales. Methods of precipitation observation and associated analyses are of strategic importance in global climate change research. As the first space-based radar, the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) has been in operation for almost 17 years and has acquired a huge amount of cloud and precipitation data that provide a distinctive view to help expose the nature of cloud and precipitation in the tropics and subtropics. In this paper we review recent advances in summer East Asian precipitation climatology studies based on long-term TRMM PR measurements in the following three aspects: (1) the three-dimensional structure of precipitation, (2) the diurnal variation of precipitation, and (3) the recent precipitation trend. Additionally, some important prospects regarding satellite remote sensing of precipitation and its application in the near future are discussed.     

柴达木盆地北缘天然气成藏模式及勘探方向

柴达木盆地北缘煤系天然气资源十分丰富阁闭面积大、保存条件较好,具备形成大中型气田的有利条件．其成藏机制复杂,具一定勘探风险．天然气成藏受烃源、圈闭、运聚和保存等条件控制,其中最重要的是各成藏条件的良好配置和沟通,生、储层烃源断层的发育,及异常高压等．结合柴北缘油气地质条件,综合考虑成藏机理和主控因素,建立了天然气成藏模式．今后柴北缘天然气勘探方向应以下侏罗统生气中心及邻近圈闭为主．     

Quantification constraints on time gap for comagmatic gold deposits： Evidence from chronological statistics

The time gap between diagenesis and mineralization （TGDM） for comagmatic gold deposits （CGD） plays an important role in confirming the genetic relationship between gold deposits and their related intrusions. With the help of preciously published isotopic ages of some typical gold deposits and their related rocks in China, the authors have discussed and quantified the distribution characteristics and scope of the TGDM. Statistical analyses and Kolmogorov tests showed that mineralizing events are either contemporaneous with or slightly postdate their cognate magma. The TGDM conforms with normal distributions at a 0.05 confidence level and clusters between 0 and 16.0 Ma with a mean of 7.0 Ma. Thus, if the TGDM of CGD is less than 16.0 Ma, it is reasonable to consider, with the aid of other evidence, the possibility of its comagmatic genetic affiliation. The authors also emphasized that to get a precise time gap it is necessary to strengthen the diagenesis-mineralization geological background of the deposits studied, and to pay attention to the study of time gap in combination with trace elements and isotope tracing.