首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   726篇
  免费   34篇
  国内免费   29篇
测绘学   284篇
大气科学   13篇
地球物理   67篇
地质学   117篇
海洋学   34篇
天文学   16篇
综合类   50篇
自然地理   208篇
  2023年   4篇
  2022年   16篇
  2021年   22篇
  2020年   17篇
  2019年   27篇
  2018年   23篇
  2017年   35篇
  2016年   40篇
  2015年   35篇
  2014年   35篇
  2013年   111篇
  2012年   44篇
  2011年   39篇
  2010年   32篇
  2009年   21篇
  2008年   19篇
  2007年   30篇
  2006年   22篇
  2005年   27篇
  2004年   15篇
  2003年   20篇
  2002年   18篇
  2001年   20篇
  2000年   13篇
  1999年   16篇
  1998年   7篇
  1997年   11篇
  1996年   10篇
  1995年   4篇
  1994年   5篇
  1993年   6篇
  1992年   5篇
  1991年   6篇
  1990年   2篇
  1989年   5篇
  1988年   6篇
  1987年   4篇
  1986年   7篇
  1985年   2篇
  1984年   4篇
  1983年   3篇
  1977年   1篇
排序方式: 共有789条查询结果,搜索用时 15 毫秒
201.
王宏俊 《山东地质》2010,(11):43-45
数字地理底图是地质环境调查不可缺少的组成部分,但现有数据大多现势性较差,如何更新值得探讨。文中提出利用Google Earth进行地理底图更新的方法,并介绍了更新的步骤和精度,该方法简单快捷、可操作性较强,具有一定的实用价值。  相似文献   
202.
利用Landsat TM图像更新地形图   总被引:3,自引:0,他引:3  
采用多项式纠正和直接线性变换两种数学模型 ,对TM图像进行几何纠正 ,获得的正射影像与地形图矢量数据配准。在Microstation 95系统下 ,进行地形图矢量数据的更新 ,并给出了相应的实验结果  相似文献   
203.
This paper explores the application of geographic information systems (GIS) in the evaluation of the accuracy of early maps through a case study of The Map of the Prefectural Capital of 1261. The evaluation of the accuracy of early maps is an important aspect of the study of the history of cartography, but no standard methodology has been generally accepted. The purpose of this paper is to assess the positional accuracy and the relative relations of the spatial objects on The Map of the Prefectural Capital using GIS. The procedure of the study includes identification of locations of the points and features of The Map of the Prefectural Capital on a modern base map, digitization of the early map and the modern base map, overlays of the digitized early map and modern base map, and an analysis of the absolute and relative distortion of the early map. The results of the analysis show that The Map of the Prefectural Capital of 1261 is reasonably accurate considering the technical ability of the thirteenth century, although it contains a considerable amount of positional displacement. In contrast to the amount of positional displacement, the relative relations among the objects are depicted much more precisely.  相似文献   
204.
For two different zonations of the Calabro-Sicilian region the macroseismic intensity attenuation parameters are computed using the Grandori model.Some modifications to this relation are proposed here in order to allow its applicability also to those cases in which the data set available for each source zone does not present three successive epicentral intensity levels (I 0) as required for its application.Maps of theoretical distribution of maximum expected intensities were plotted for both zonations adopted, in order to test the reliability, also using other attenuation models.The results of the analysis show how the proposed modifications to the Grandori relation allow the macroseismic intensity attenuation modelling even in cases in which only one intensity level is available.Finally, the comparison of theoretical maximum expected intensity distribution maps, computed for different attenuation models and seismogenic zonations, shows that the maps plotted using the Grandori model and the zonation adopted by G.N.D.T. (Gruppo Nazionale Difesa dai Terremoti - C.N.R. Italy) are more reliable.  相似文献   
205.
We have carried out stratigraphic mapping in the Upper Miocene basalt lava pile around the fjords Mjoifjördur and Seydisfjördur, eastern Iceland. The mapping is based on conventional methods including the use of interbasaltic clastic horizons and petrographically distinct lava groups. These units are also used to provide correlations with the Nordfjördur area south of Mjoifjördur. We present a 3-km composite stratigraphic column for the area between Mjoifjördur and Seydisfjördur. The geology of this area shows some differences from the classical model of Walker for the structure of eastern Iceland partly due to the fact that most of Mjoifjördur is not in the vicinity of central volcanoes. Detailed laboratory measurements of remanent magnetization were carried out on oriented core samples from 363 lavas in 10 selected profiles. The local paleomagnetic polarity stratigraphy supports correlations made on the basis of other criteria. Over 20 geomagnetic reversals are recorded in the eastern Iceland lava pile in a period approximately 13-10 Ma ago. The geomagnetic field during this period averages to a central axial dipole field, and its overall statistical properties resemble those obtained in earlier surveys in Iceland.  相似文献   
206.
Mental Maps and Fuzziness in Space Preferences*   总被引:1,自引:0,他引:1  
Mental maps are widely used to represent aggregate residential preferences in a population. This study examines the contention by researchers that the dominant viewpoint in a group in terms of residential desirability is not affected by the fuzziness in individual space preferences. Results indicate that a significant misrepresentation of group preferences can result when fuzziness of individual preferences is overlooked. The use of ordinal scales to generate mental maps is likely to distort the actual pattern of residential preferences that dominates in the group because of the failure of the ranking approach to account for imprecision and ambiguity in individual preferences. Because interval scales used in rating or evaluating tasks do not force individuals to give a crisp judgement of places, they are more adequate than ordinal scales for mental mapping and for behavioral analysis.  相似文献   
207.
Soil maps can be used to generate maps showing the areal distribution of bedrock. This technique is especially useful in heavily vegetated areas where weathering is intense and outcrops sparse. Broad lithologic categories that are readily distinguished include: diabase/basalt, sandstone, shale, limestone, conglomerate, and hornfels. Using soil maps is not a substitute for field work, but is a valuable tool to aid in making geologic maps. Soil maps can also be used to produce derivative maps showing slope steepness and landslide distribution.  相似文献   
208.
重庆城市地貌图的设计和编制   总被引:5,自引:0,他引:5  
刁承泰 《地理学报》1993,48(6):544-551
本文从设计意图、设计内容和编制方法等方面,总结了重庆城市地貌制图中取得的一些主要经验,探讨了城市地貌图的特点。  相似文献   
209.
蔡先华  王浪  付晓 《测绘通报》2020,(5):130-133
城市交通网络规模的不断扩大使得交通线路图成为一种常用地图。为了提高信息的传输效率,更好地保证图形的清晰易读性,出现了变形交通线路地图[1]。本文分析了变形交通线路图特性并对其自动制作过程进行了总结。为解决制作过程中地图符号冲突问题,提出了作用力驱动站点位移的交通线路图变形压缩方法。建立交通线路图中站点受力移动模型并设计了以坐标轴为轴心的移位算法。试验表明,该算法能够有效解决地图符号冲突问题,为完全自动制作变形交通线路图建立了基础。  相似文献   
210.
基于3DS MAX的城市小区3维图的制作   总被引:5,自引:1,他引:5  
依据3DSMAX软件制作城市3维图的原理与方法,利用某一城市小区2维平面图的矢量数据,制作了城市小区3维图。重A介绍了基于3DSMAX环境的城市小区3维图的制作过程、制作工艺、建筑物的立体建模、材质贴图、灯光设置等关键技术。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号