全文获取类型
收费全文 | 2118篇 |
免费 | 129篇 |
国内免费 | 96篇 |
专业分类
测绘学 | 591篇 |
大气科学 | 60篇 |
地球物理 | 75篇 |
地质学 | 446篇 |
海洋学 | 202篇 |
天文学 | 4篇 |
综合类 | 171篇 |
自然地理 | 794篇 |
出版年
2024年 | 6篇 |
2023年 | 22篇 |
2022年 | 73篇 |
2021年 | 78篇 |
2020年 | 55篇 |
2019年 | 95篇 |
2018年 | 41篇 |
2017年 | 107篇 |
2016年 | 94篇 |
2015年 | 89篇 |
2014年 | 119篇 |
2013年 | 178篇 |
2012年 | 128篇 |
2011年 | 113篇 |
2010年 | 103篇 |
2009年 | 83篇 |
2008年 | 125篇 |
2007年 | 108篇 |
2006年 | 99篇 |
2005年 | 87篇 |
2004年 | 63篇 |
2003年 | 67篇 |
2002年 | 65篇 |
2001年 | 54篇 |
2000年 | 49篇 |
1999年 | 48篇 |
1998年 | 38篇 |
1997年 | 24篇 |
1996年 | 14篇 |
1995年 | 14篇 |
1994年 | 12篇 |
1993年 | 17篇 |
1992年 | 5篇 |
1991年 | 11篇 |
1990年 | 7篇 |
1989年 | 5篇 |
1988年 | 12篇 |
1987年 | 7篇 |
1986年 | 6篇 |
1985年 | 7篇 |
1984年 | 10篇 |
1983年 | 1篇 |
1982年 | 3篇 |
1980年 | 1篇 |
排序方式: 共有2343条查询结果,搜索用时 15 毫秒
941.
The organisational context of retail locational planning 总被引:1,自引:0,他引:1
Retailers have a large number of techniques at their disposal to assist them in their locational planning, but the use made
of them is varied, regardless of their intrinsic merits. The reasons for this lie very much in the organisational context
in which the techniques are applied. This paper discusses the nature of locational planning and decision making, and puts
forward a framework which links locational planning and the organisational settings in which it takes place. The preliminary
results of a survey of the use of techniques by U.K. retailers are presented, which show that while most companies use more
than ‘Rules of Thumb’, it is the simplest techniques which are the most widely used. The application of the more advanced
knowledge based methods is still relatively uncommon. The explanation for the variations lies in the attributes of the techniques
themselves, the types of locational planning undertaken, and the structural and cultural characteristics of the companies.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
942.
城市交通系统与土地利用结构关系研究 总被引:24,自引:0,他引:24
阐述了城市交通系统与土地利用结构的内涵及其相互之间循环的作用与反馈关系,并指出城市交通规划的重要性及其过程中城市活动系统分析的意义。 相似文献
943.
Protected areas (PAs) are the most effective tools to protect biodiversity and ecosystem services. They have proven to be effective in stopping extensive land use conversion in well-conserved terrestrial ecosystems. However, land cover changes around PAs threaten biodiversity and ecosystem services within their limits and reduce ecological connectivity. In this study, we analysed the urban sprawls on the boundaries of 159 PAs (national, regional, and natural parks) in Spain, using 2.5 and 5 km non-protected buffer zones from 1990 to 2018. We clustered PAs based on biophysical and socio-economic characteristics and modelled urban sprawl in different buffers and periods. Hierarchical clustering revealed three groups of PAs: (a) proximate urban parks, (b) mountainous parks, and (c) parks in the Madrid autonomous region. We found that urbanisation in the surroundings of PAs in Spain has nearly doubled since 1990. General linear models explained a significant proportion of the urbanisation trends observed, with the number of municipalities in the boundary of the PA, the distance to a main road, and the distance to a big city acting as the most important drivers of urban sprawl. Our results also show that some PAs exert significant effects on urbanisation trends in their surroundings through the park-view effect. Finally, we highlight three coexisting phenomena that might explain the observed urban sprawl processes: (a) PAs attracting urbanisation in their surroundings due to the park-view effect, (b) PAs as a deterrent for urban sprawl within their limits, and (c) PAs occupying residual areas among previously urbanised lands. 相似文献
944.
城市的低碳发展对于应对气候变化及实现我国“碳达峰、碳中和”目标起着至关重要的作用。在新的国土空间规划体系下,国土空间总体规划对城市的低碳发展影响重大。为解决现有的城市温室气体核算中存在的问题,使总体规划促进城市低碳发展,构建了国土空间总体规划温室气体核算模型。该模型基于“空间布局—用地类型—部门划分—模型方法”的框架,采用自上而下与自下而上相结合的方法,与国土空间规划要素紧密结合;建立了市域和中心城区两个层次的碳排放核算方法,并解决了中心城区的碳排放核算问题,可进行国际间比较;解决了总体规划能源预测不完善的问题,提出了不同的核算方法供灵活选择,与完全基于用地类型的方法相比,降低了不确定性。最后基于模型提出了评估总体规划低碳发展水平的核心指标与参考指标。 相似文献
945.
土地利用对街头抢劫影响的空间分异模式:以H市为例 总被引:2,自引:5,他引:2
选取H市中心城区2009年和2010年发生的街头抢劫案件为研究对象,构建地理加权泊松回归GWPR模型,探讨不同性质土地利用对案件影响的空间差异性。研究表明,各类用地与街头抢劫的关系存在显著的空间异质性。其中,位于中心区外围的传统居住区和部分新建社区等居住用地对街头抢劫存在显著的负向影响;商业服务业设施用地对街头抢劫的影响总体上显著性不强,但与其中的商业设施点类型密切相关,独栋高层的商业综合体会使犯罪数量下降,而临街商铺形式的商业设施点则是犯罪高发区域;工业用地仅对老城区的街头抢劫产生正向影响;公园绿地总体上与街头抢劫案件呈负相关性,但城市开敞绿地多的地方案件数量也较多;交通设施用地与街头抢劫的关系则受到交通设施、道路等级、路网形态的影响。最后通过聚类分析发现,土地利用对案件影响的主导因素的空间分异模式与不同的城市功能分区有一定的对应关系,可以对每个功能分区根据其街头抢劫发生的主导因素制定相应的土地利用规划导则。 相似文献
946.
REUBEN S. ROSE‐REDWOOD 《Geographical review》2011,101(3):396-413
In this article, I examine the performative dimensions of historical narration as a form of modern mythmaking by reconsidering conventional narratives on the “origins” of Manhattan's grid street plan of 1811. The historical mythology of the grid espoused in canonical readings of the Plan of 1811 relies extensively on a rearticulation of the official explanation that the grid's designers provided in a foundational text known as the “Commissioners’ Remarks”. I argue that such accounts result in an extraordinarily narrow and formulaic interpretation of the utilitarian motives and intentions behind the city's grid plan, one that reinforces a form of “morphological essentialism”. To support this argument, I shift the focus of attention beyond the “Commissioners’ Remarks” in order to complicate readings of the intentionality that gave rise to the 1811 street plan. I conclude by suggesting that the mythic search for the “origins” of the grid in the realm of founding intentions can most effectively be challenged by drawing attention to the proliferation of countermyths of gridded space. 相似文献
947.
Paul Swagemakers Damian Copena Rodríguez María Dolores Domínguez García Xavier Simón Fernández 《Geografisk tidskrift / udgivet af Bestyrelsen for Det Kongelige danske geografiske selskab》2013,113(2):109-118
Modification and channelization of streams and rivers have been conducted extensively throughout the world during the past century. Subsequently, much effort has been directed at re-creating the lost habitats and thereby improving living conditions for aquatic organisms. However, as restoration methods are plentiful, it is difficult to determine which one to use to get the anticipated result. The aim of this study was to compare two commonly used methods in small Danish streams to improve the physical condition: re-meandering and passive restoration through cease of maintenance. Our investigation included measurement of the physical conditions in 29 stream reaches covering four different groups: (1) re-meandered streams, (2) LDC streams (the least disturbed streams available), (3) passively restored streams (>10?years stop of maintenance) and (4) channelized and non-restored streams. The in-stream habitats were compared through analysis of the measured physical parameters and by applying a habitat model. We found that re-meandering is a more effective way of re-creating near-natural physical conditions in small streams compared to passive restoration. This is probably due to the limited energy in small streams which restricts re-shaping of the stream channel. However, based on habitat suitability modelling, the change to the physical condition did not translate into improved habitat suitability for young of the year brown trout highlighting the value of using several methods when evaluating restoration success. 相似文献
948.
Mary Wenning 《The Professional geographer》2013,65(3):426-428
Since the launch of the U.S. Department of Homeland Security in 2002, research needs have been established in the areas of disaster preparedness and critical infrastructure protection. Disaster preparedness seeks to lessen the adverse effects of catastrophes by planning in advance and instituting a proper response. Critical infrastructures are those entities deemed necessary for society to function correctly and thus require protection. Recent studies have used location models to aid in the management of many of these crucial establishments, but few efforts have modeled where to geographically site a future critical supply facility. Furthermore, no research has explored a multihazards approach for siting critical supply facilities and the explicitly spatial factors that make a potential target vulnerable to attack. In this article, we propose a strategic multiobjective modeling framework for siting critical supply facilities that incorporates explicitly spatial disaster preparedness directives and critical infrastructure protection demands. We detail the spatial data requirements and modeling assumptions and present results from an application involving the placement of critical vaccine stores in Orlando, Florida. 相似文献
949.
地理信息系统与遥感在城市和农业土地利用规划中的应用综述 总被引:2,自引:0,他引:2
本文在参考大量自80年代以来国内外地理信息系统与遥感研究和应用文献的基础上,回顾了地理信息系统与遥感在城市和农业土地利用规划中的广泛应用。旨在使更多的人们关注地理信息系统与遥感的研究成果,以使地理信息系统与遥感为规划机构和决策者们提供更为广泛和实用的地理信息。 相似文献
950.
《Urban geography》2013,34(8):691-722
Interest in the concept of "quality of life" (QOL) has increased exponentially in many areas of public policy. A constant theme in QOL research in the last 30 years has been a focus on the measurement and the types of indicators utilized. The objective of this paper is to identify the structure, spatial variation, and change in quality of life from 1991 to 1996 within Saskatoon, Saskatchewan by using a range of indicators relating to the social and physical environment, modified by perception. The QOL model u ed was developed by combining aspects of Cutter's (1985) geographical model of quality of life and Myers' (1987) community of quality of life model to assess QOL over time from a geographical perspective. The integration of objective, subjective and perceptual indicators, using a survey of Saskatoon residents, allowed for a broader interpretation of quality of life than is normally the case. The structure of QOL identified from the results of a series of principal component analyses consistently identified two important structures, structures of general affluence and general disadvantage. Results showed that the most disadvantaged residents in 1991 and 1996 were living to the west of the Central Business District, clustered in several neighborhoods, while residents enjoying a higher QOL tended to live in the suburbs toward the periphery of Saskatoon. 相似文献