中国1∶100万景观生态制图设计   总被引：5，自引：0，他引：5  

程维明  柴慧霞龙恩  刘海江张旸 《地球信息科学学报》2004,6(4):19-24

中国1∶100万景观生态图系借鉴国内外传统景观制图方法和制图规范,在遥感、地理信息系统先进技术的支持下,设计研制其制图方法、制图内容、样图和技术流程,同时提出初步的景观分类系统,为今后编制中国1∶100万景观生态图奠定基础。  相似文献   

A synthesis map of the sky at 34.5 MHz     

K. S. Dwarakanath  N. Udaya Shankar 《Journal of Astrophysics and Astronomy》1990,11(3):323-410

This paper describes a wide-field survey made at 34.5 MHz using GEETEE,1 the low frequency telescope at Gauribidanur (latitude 13°36′12′′N). This telescope was used in the transit mode and by per forming 1-D synthesis along the north-south direction the entire observable sky was mapped in a single day. This minimized the problems that hinder wide-field low-frequency mapping. This survey covers the declination range of-50° to + 70° (- 33° to +61° without aliasing) and the complete 24 hours of right ascension. The synthesized beam has a resolution of 26′ x 42′ sec (δ- 14°. 1). The sensitivity of the survey is 5 Jy/beam (1σ). Special care has been taken to ensure that the antenna responds to all angular scale structures and is suitable for studies of both point sources and extended objects This telescope is jointly operated by the Indian Institute of Astrophysics, Bangalore and the Roman Research Institute, Bangalore.  相似文献   

AN EVALUATION OF SAS/GRAPH SOFTWARE FOR COMPUTER CARTOGRAPHY1     

Alan M. Baker  Rowan Faludi  David R. Green 《The Professional geographer》1985,37(2):204-214

The SAS® computer software system, widely used and respected for its capabilities in statistical analysis and data base management, now includes a new set of graphic and cartographic procedures called SAS GRAPH?. We have used these cartographic procedures in research on mapping ethno-cultural census data from metropolitan areas in Ontario and in undergraduate and graduate courses in computer cartography. On the basis of that experience, we describe and evaluate SAS/GRAPH'S cartographic capabilities and illustrate with maps drawn by various devices.  相似文献   

冰碛扇型砂金矿床特征及其成矿初探     

杨文智 《河南国土资源》1997,(2)

成生于冰碛扇内，经一定的生物、物理、化学成矿作用，以砂金形态分布而富集成矿的金矿称为冰碛扇型砂金矿床。它具有沿造山带一定标高范围成群、成带分布，沉积物为近源且半胶结，砂金呈面状分布，并以粒金、块金为主，具胶状、浑圆状、包块状构造形态，分布极不均匀等特征。冰碛扇型砂金矿床的成矿作用与河成砂金矿床有本质的区别。它的成矿作用模式是：造山带下地壳富含的活化金通过新构造运动活化的断裂运移地表，经地下流体和地表流体的迁移聚集到冰碛扇这一封闭稳定的生物、物理、化学障环境中，主要经高效聚金微生物有机胶体成矿作用沉淀、再生加大形成砂金，逐步富集成矿床。而红色磨拉石建造中风化离解的Ｆｅ，Ｍｎ物质对沉淀环境ｐＨ值起着一定的调节作用。冰碛扇型砂金矿床在我国西部造山带内广泛分布，具有一定的工业价值，是砂金矿床中一重要类型，应予以重视  相似文献   

Biological and granulometric controls on sedimentary organic matter of an intertidal mudflat     

Lawrence M. Mayer  Peter T. Rahaim  William Guerin  Stephen A. Macko  Les Watling  Franz E. Anderson 《Estuarine, Coastal and Shelf Science》1985,20(4):491-503

A variety of measures of organic matter concentration and quality were made on samples collected from the top few mm of intertidal mudflat sediment over the course of a year, in order to assess the relative importance of biological and sedimentological influences on sedimentary organic matter. Winter and summer were times of relatively fine-grained sediment accumulation, caused by biological deposition or stabilization processes and resulting in higher organic matter concentrations. Stable carbon isotope and Br:C ratios indicated a planktonic source of bulk organic matter. Ratios of organic carbon to specific surface area of the sediments were consistent with an organic monolayer coverage of sediment grains. Correction for changing grain size during the year showed no change in the organic concentration per unit surface area, in spite of organic matter inputs by in situ primary production, buildup of heterotroph biomass and mucus coatings, and biodeposition of organic-rich seston. There were also no indications of changes in bulk organic quality, measured as hydrolyzable carbohydrates and amino acids, in response to these biological processes. It is concluded that biological processes on a seasonal time scale affect the bulk organic matter of these sediments via a modulation of grain size rather than creation or decay of organic matter.  相似文献   

上扬子地台震旦系铅锌矿床类型及找矿方向   总被引：13，自引：0，他引：13  

齐文  侯满堂  王根宝 《地球科学与环境学报》2006,28(2):30-36

上扬子地台含铅锌矿地层主要为震旦系。震旦系在上扬子地台主要发育上统灯影组,次有下统陡山沱组。将上扬子地台震旦系铅锌矿床成因划分为一级为叠生矿床,二级为层控矿床,三级为热水沉积改造矿床和热水沉积再造矿床四级类型,该类型按铅锌比例进一步划分为富铅型、富锌型、铅锌共生型。研究区内最重要的铅锌矿床成因类型为南郑马元、会东大梁子铅锌矿为代表的富锌型。陕西南郑、紫阳—镇坪地区,湖北武当、神农架、黄陵地区,以及地台西缘的安宁河、甘洛—小江、峨边—寻甸等地区的震旦系是寻找铅锌矿的最有利地段。  相似文献   

The O4f + O6V eclipsing binary system Sk−67°105 in the Large Magellanic Cloud     

Pablo G. Ostrov  Emilio Lapasset 《Monthly notices of the Royal Astronomical Society》2003,338(1):141-146

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BACKGROUND STUDY ON NON-RESIDUAL PHASE OF ELEMENTS IN CHANGJIANG AND HUANGHE ESTUARINE SEDIMENTS     

刘新威  吴景阳  蔡月琴  林荣根  韩桂荣 《中国海洋湖沼学报》1996,14(3):282-290

Analysis of Zn, Cu, Pb, Co, Cr, Li, Ni, K, Al, Fe extracted by 1 mol/L HCl or 0.5 mol/LHCl/H_2O_2, showed concentrations of Zn, Cu, Pb, Co, Cr, Fe, Ni were significantly correlated with Li, Al,K, and clay. Two methods are used to indicate the background value of the non-residual phase of elementsin sediments, and are the same as the methods used to indicate the background value of totalconcentrations in sediments. The first method uses correlograms and regression equations,the second usesthe mean element concentrations normalized with grain size. Li, Al, K can be used as reference elements to determine the background value of Zn, Cu, Pb, Co,Cr, Ni, Fe, while the clay concentration's correlation with some extractable concentrations can be used tocalculate the background value of the non-residual phase of elements as a percentage of clay concentrationin the sediments. Based on this study, the concept of using the background value of the non-residualphase of elements to compare the pollution level in differ  相似文献   

Analysis of mapping coverage obtained from spacecraft     

Anastassios E. Petropoulos  James M. Longuski 《Celestial Mechanics and Dynamical Astronomy》1994,60(4):431-454

An exact analysis of the coverage obtained by spacecraft using cross-track scanning and nadir-centered conical imaging, under imposed viewing obliqueness and resolution requirements, is presented. In addition to exact expressions for the area acquired and the area acquisition rate, envelope theory is introduced to obtain the boundary of the imaged area. These expressions are relatively compact, allowing rapid machine computation. The effects of the sun phase angle, and of imaging system limitations are also examined. The Galileo mission encounter with Callisto is used as a numerical example, from which certain general conclusions are drawn regarding optimal imaging trajectories.  相似文献   

含有集约束向量极值问题的最优性条件     

吴泽忠 《成都信息工程学院学报》2004,19(2):258-262

在序线性拓扑空间里研究了含有集约束向量极值问题的最优性条件,并建立了充分性和必要性条件.  相似文献