全文获取类型
收费全文 | 645篇 |
免费 | 29篇 |
国内免费 | 30篇 |
专业分类
测绘学 | 249篇 |
大气科学 | 15篇 |
地球物理 | 73篇 |
地质学 | 125篇 |
海洋学 | 33篇 |
天文学 | 16篇 |
综合类 | 43篇 |
自然地理 | 150篇 |
出版年
2023年 | 5篇 |
2022年 | 11篇 |
2021年 | 16篇 |
2020年 | 12篇 |
2019年 | 23篇 |
2018年 | 18篇 |
2017年 | 28篇 |
2016年 | 37篇 |
2015年 | 29篇 |
2014年 | 35篇 |
2013年 | 98篇 |
2012年 | 38篇 |
2011年 | 34篇 |
2010年 | 32篇 |
2009年 | 20篇 |
2008年 | 16篇 |
2007年 | 26篇 |
2006年 | 19篇 |
2005年 | 24篇 |
2004年 | 14篇 |
2003年 | 21篇 |
2002年 | 16篇 |
2001年 | 19篇 |
2000年 | 13篇 |
1999年 | 17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 | 3篇 |
1986年 | 6篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1983年 | 1篇 |
1977年 | 1篇 |
排序方式: 共有704条查询结果,搜索用时 15 毫秒
391.
As we experience places, we learn about those places and generalize information into more abstract geographic categories. Rosch's basic-level theory argues that information known about objects is stored in our memories in a three-layered hierarchy. Data that could be used to test this theory in a geographic context was generated by having subjects make lists of activities, characteristics, and parts associated with 11 familiar geographic categories. An analysis of the distribution of information among the geographic categories confirmed two basic predictions of Rosch's theory. Significantly more information was stored in the basic-level geographic categories country, region, state, city, and neighborhood than in the superordinate category place. Significantly more information was not stored in subordinate categories home country, home region, home state, home city, and home neighborhood. The results suggest that geographic information is efficiently stored in memory so that much of what we know about geographic space is stored in basic-level categories that are both distinctive and informative. 相似文献
392.
一种矢量GIS数据模型及其关系数据结构 总被引:1,自引:0,他引:1
提出一种适合于多值矢量图的GIS数据模型(包括图形数据模型和属性数据模型)。该模型既适合于关系数据库结构,也适合于面向对象数据库结构。根据该模型设计了一种基于关系数据库模型珠图形与属性一体化数据结构。该模型和结构既适用于二维图,也适用于数字地面模型(DTM)。该数据结构已应用于GIS软件(GISID)中,效果很好。 相似文献
393.
394.
利用SPOT卫星遥感影像测绘1:50000地形图的探讨 总被引:5,自引:0,他引:5
目前,高分辨率的卫星遥感影像逐步商业化,国内外不断把卫星遥感影像应用于测绘领域。本文主要分析,研究利用SPOT卫星遥感影像测绘1:50000地形图的地理精度和地物判断能力,认为在山地,高山地地区基本上可以利用SPOT卫星遥感影像测绘1:50000地形图。 相似文献
395.
航摄像主点符号化索引图的制作技术 总被引:1,自引:0,他引:1
传统的像片索引图制作方法存在工艺繁琐、手工操作步骤多、作业效率低等缺点。为提高航摄成果整理的作业效率 ,本文提出了一种新的像片索引图的概念———航摄像主点符号化索引图。航摄像主点符号化索引图的制作是基于 1∶10 0万数字线划地图 (DLG)数据库 ,将航摄鉴定表信息、像片覆盖信息、航空摄影信息和地物要素信息综合起来 ,以 1∶10万或 1∶5万地形图为分幅单元叠加整饰制图。实验结果证明航摄像主点符号化索引图不仅注记要素齐全 ,版面整洁、美观 ,而且以标准地形图为分幅整饰单元 ,有利于航摄像片的测区、分区、图廓覆盖、航线分布等情况的检查与验收 ,有利于航摄成果资料的统一管理 ,以及测图时像片的快速检索。 相似文献
396.
Landslide Susceptibility Models Utilising Spatial Data Analysis Techniques. A Case Study from the Lower Deba Valley,Guipuzcoa (Spain) 总被引:2,自引:0,他引:2
Remondo Juan González-Díez Alberto De Terán José Ramón Díaz Cendrero Antonio 《Natural Hazards》2003,30(3):267-279
A quantitative methodology for landslide susceptibility zonationis described and its application to a study area in the lower part of the Deba Valley (Guipúzcoa,Spain) presented. Susceptibility models were obtained on the basis of statisticalrelationships between known mass movements and conditioning factors. A landslide rupturehypothesis was set and a digital database consisting of seventeen causal factors layers constructed.The modelling procedure was implemented utilising a GIS. The susceptibility analysis methodis based on the Favourability Functions approach, and two different mathematicalframeworks: probability theory and Zadehïs fuzzy set theory. Several landslidesusceptibility models were produced and validated using different sets of independent landslide data.The predictive capability of models was determined. 相似文献
397.
Sequence architecture and carbonate platform configuration (Late Cenomanian–Santonian), Sinai, Egypt
Abstract Relative sea‐level changes on the mixed carbonate–siliciclastic platform of Sinai are manifested in shifts of distinct facies belts (deep‐water facies, high‐energy subtidal, shallow subtidal, lagoon, shallow shoreface siliciclastics, supratidal) and are interpreted in terms of sequence stratigraphy. Eight sedimentary sequences are recognized for the Upper Cenomanian to Santonian. Their correlation along a north–south transect reveals distinct changes in lithofacies and progradation/retrogradation patterns within the individual systems tracts. The number and stratigraphy of the sequence boundaries of Sinai correlate well with those from adjacent areas. Patterns of increased subsidence are documented for the Central Sinai Basin since the Late Cenomanian by increased thickness of the stratal packages (post‐CeSin 7 HST, post‐TuSin 1 LST and HST, post‐TuSin 2 LST) and are balanced by varying accumulation rates. Based on new sedimentological and biostratigraphic data, large‐scale palaeogeographic maps and cross‐sections show the: (1) temporal and spatial evolution of the Central Sinai Basin, e.g. its latest Cenomanian initial formation, Lower Turonian deep‐water facies, Middle Turonian to Coniacian synsedimentary subsidence; (2) drowning of the Cenomanian platform coinciding with the latest Cenomanian to Early Turonian relative sea‐level rise; (3) re‐establishment of the platform in Middle–Late Turonian times; and (4) a Coniacian basin and swell morphology. 相似文献
398.
This paper deals with the probabilistic seismic hazard analysis carried out in the Oran region, situated in the Northwest of Algeria. This part of Algeriawas historically struck by strong earthquakes. It was particularly affected during theOctober 9, 1790 Oran earthquake of intensity X. The main purpose of this work is to assessseismic hazard on rocks in order to provide engineers and planners with a basic tool for seismicrisk mitigation. The probabilistic approach is used in order to take into account uncertaintiesin seismic hazard assessment. Seismic sources are defined in the light of the most recentresults obtained from seismotectonics analyses carried out in North Algeria.Source parameters such as b-values, slip rate and maximum magnitude are assessed for eachseismic source. The attenuation of ground shaking motion with distance is estimated byusing attenuation relationships developed elsewhere throughout the world (Sadigh et al., 1993; Ambraseys and Bommer, 1991). The two relationships agree well with the local data. Differentchoices of source parameter values and attenuation relationships are assigned weights in alogic tree model. Results are presented as relationships between values of peak groundacceleration (PGA) and annual frequency of exceedance, and maps of hazard for returnperiods of 200 years and 500 years. A maximum peak ground acceleration of 0.42 g is obtainedfor the Oran site for a return period of 500 years. 相似文献
399.
In this paper we initially present a critical review of a range of ethnological maps produced over the last 130 years for
highland northern Vietnam. In particular we illustrate the many difficulties faced when trying to represent mosaics of ethnic
highland minority groups on two dimensional maps. Such historical maps included no attempts to bring topographic details into
the picture, an idea that would have been virtually impossible anyway, given the cartographic technologies at the time. Yet
by not including such details or not representing them clearly, a partial image of these populations has been created that,
over time, has become a standardised representation. Therefore, as a more systematic approach to the analysis of these highland
minority groups, we present recent attempts to create more functional maps and models for the northern Vietnam province of
Lao Cai, using modern cartographic techniques and geographic information systems. Utilising tools such as digital cartography
and digital elevation models a wealth of information can be gained which has the potential, amongst other possible uses, to
allow for a greater understanding and sensitivity regarding ethnic minority groups in Northern Vietnam, and their use of the
local environment.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
400.