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排序方式: 共有245条查询结果,搜索用时 15 毫秒
101.
在分析总结Auto CAD大比例尺地形图制图作业面临的现实问题的基础上,开发了Auto CAD大比例尺地形图制图工具包,使用Access数据库存储制图操作流程及相关参数,通过编程使制图工具能够依数据库自动生成,降低了制图工具定制的门槛,大幅减少了制图作业中的重复劳动。 相似文献
102.
During the period of 3—5 August 1996(for short "96.8"),an extraordinary rainstorm event occurred in Henan,Hebei and Shanxi Provinces in China,resulting in severe flood catastrophe.Synoptic analyses indicated that the stable gross col field and the interaction between a northward moving typhoon(down into low pressure)and its east lateral Pacific subtropical high were the large-and meso-scale circulation conditions of the "96.8" extraordinary rainstorm.The mesoscale typhoon-low and its specific dynamical and thermodynamical structures were directly related to this rainstorm event.The nonhydrostatic version of mesoscale numerical model MM5 was used to conduct investigation of numerical simulation for this case.The simulation with the full physical processes of nonhydrostatic version MM5 was basically possessed of a capability to reproduce the genesis,development and evolution of the large-scale and meso-α scale synoptic systems.The simulative results using a two-way interactive nesting procedure revealed that the typhoon-low was possessed of an intensive coupled mechanism between the dynamical and thermodynamical fields,namely,the developing typhoon-low was possessed of a structure of the.cyclonic vorticity column with warm center and high humidity,the vorticity column on the lower levels was the moist convective instability and negative moist potential vorticity structure:the intensive ascending vertical motion and the intense divergence on upper levels and intensive convergence on the lower levels as well as the development of the convective cloud cluster were intercoupling:the intense southern wind jet companied by the typhoon-low was not only the interaccompanying and intercoupling condition of the development and maintenance of the typhoon-low and convective cloud cluster,but also was the transportable belt of the moisture source and heat energy of the "96.8" extraordinary rainstorm.The analysis of simulative results of precipitation indicated that the distribution of the rainfall belt and rainfall rate was basically consistent with that of the observation in spite of some rainfall centers less or larger than those of the observation for coarse or fine mesh domain,respectively. 相似文献
103.
小尺度环境地形认知与空间行为的关系分析——以南京大学浦口校区为例 总被引:4,自引:0,他引:4
地形认知与空间行为间的交互影响是重要的人地关系,也是行为地理学近期重视的课题,但相关研究甚少。为考察日常活动中的上述交互作用,文章选择南大浦口校园为案例区,在预研究基础上,采用分层比例抽样,分别抽取认知与行为样本,并运用言语描述和草图方法获得被试的认知与行为数据。随后,通过绘制公共地形认知与行为地图及地理环境编码等定性方法,同时使用空间叠置与缓冲区及偏相关定量分析方法,得到以下结论:① 被试在认知地图中已编码了地形高程的等级秩序,基本认知了研究区的地形空间格局。② 校园行为节点以必要性活动场所为主,自发性活动与社会性活动场所为次;必要性活动路径分布于校园南部,呈直线,两端连接生活区和教学区;而自发性活动路径离散分布,连接更多的运动场所和环境景点。③ 地形认知与空间行为存在交互影响,具体表现为:地形认知影响了行为的空间格局,但此影响受行为的动机和效率认知的调控;反之空间行为是影响地形认知的主要因素,其影响受行为的动机与持续时间的调控。④ 宿舍位置是影响地形认知与空间行为交互作用的主要因素,而性别与学科的影响不显著。最后探讨了研究不足及发展方向。 相似文献
104.
人地关系地域系统与可持续发展的相互作用机理初探 总被引:34,自引:5,他引:34
地理学研究的核心为人地关系地域系统。人地关系理论的研究与实践操作对可持续发展的内涵认知有着举足轻重的影响。同时,人地系统本身也必须得到发展,这样才能促进可持续发展内涵的丰富化与哲理化。在当代世界范围内的可持续发展思想的困惑越来越多的情况下,研究了人地关系地域系统和可持续发展系统的相互作用机理,探讨了人地系统的发展本质、可持续发展的本质、人地协调发展的时空背景、二者相互作用机理的哲学本质等问题 相似文献
105.
“96·8”特大暴雨和中尺度系统发展结构的非静力数值模拟 总被引:11,自引:0,他引:11
1996年 8月 3~ 5日 (“96· 8”) ,中国河南、山西、河北等省发生了一次特大暴雨过程 ,造成了严重洪涝灾害。文中的天气分析指出 ,稳定的大型鞍形场和北移台风 (登陆后减弱为低压 )与其东侧副热带高压的相互作用是“96· 8”特大暴雨发生的大、中尺度环流条件 ;而中尺度低压及其特有的动力热力结构与该暴雨过程直接相关。对该过程采用非静力中尺度数值模式 (MM5)进行了数值模拟研究。模拟结果分析发现 ,非静力 (MM5)的全物理过程模拟基本上可再现大尺度和中 -α尺度天气系统的发生、发展和演变。采用二重网格双向嵌套技术的细网格模拟结果揭示 ,低压的动力场和热力场之间具有一种强耦合机制 ,即发展的低压具有气旋性涡柱的暖心高湿结构 ,在涡柱低空是湿对流不稳定和负湿位涡结构 ;强垂直上升运动与高空强辐散和低空强辐合以及对流云团的发展互耦 ;与低压相伴的强南风急流不仅是低压和对流云团发展与维持的互伴互耦条件 ,而且也是“96· 8”特大暴雨的水汽源和热能输送带。降水模拟结果分析表明 ,尽管某些降水中心对粗网格偏小 ,对细网格偏大 ,但雨带和雨强分布与观测结果基本一致。 相似文献
106.
107.
Bjørn T. Asheim 《GeoJournal》1999,49(4):345-352
This article analyses the role of interactive learning and localised knowledge in globalising learning economies. Some authors argue that as a result of globalisation and codification processes the importance of local, contextual knowledge and localised learning is decreasing, and, thus, the competitive advantage of high-cost regions (and nations) are steadily being undermined. Other authors maintain that much strategic knowledge, tacit as well as codified, is disembodied (i.e., knowledge which is the result of positive externalities of the innovation process), and, thus, remains `sticky'. Important parts of the learning process continue to be localised as a result of the enabling role of geographical and social proximity in stimulating interactive learning, which taken together represent strong `untraded interdependencies' constituting important context conditions for regions to remain innovative and competitive. The article argues that learning economies should be used to conceptualise a specific historical period of capitalism in which knowledge and learning has attained an increasing importance in the economy. This period of capitalist development is also referred to as post-Fordism. 相似文献
108.
Total sea surface temperature (SST) in a coupled GCM is diagnosed by separating the variability into signal variance and noise
variance. The signal and the noise is calculated from multi-decadal simulations from the COLA anomaly coupled GCM and the
interactive ensemble model by assuming both simulations have a similar signal variance. The interactive ensemble model is
a new coupling strategy that is designed to increase signal to noise ratio by using an ensemble of atmospheric realizations
coupled to a single ocean model. The procedure for separating the signal and the noise variability presented here does not
rely on any ad hoc temporal or spatial filter. Based on these simulations, we find that the signal versus the noise of SST
variability in the North Pacific is significantly different from that in the equatorial Pacific. The noise SST variability
explains the majority of the total variability in the North Pacific, whereas the signal dominates in the deep tropics. It
is also found that the spatial characteristics of the signal and the noise are also distinct in the North Pacific and equatorial
Pacific. 相似文献
109.
110.
能源和地缘政治的互动模型 总被引:1,自引:0,他引:1
运用系统分析法,第一步建立了能源出口国-过境运输国-进口国的能源利益体双循环模型,第二步建立了以跨国公司、政府、国际组织为载体的地缘政治体双循环模型,最后将两者叠加,得出能源与地缘政治的互动模型。认为:出口国、进口国、过境运输国分别通过提供国际公共品、获取能源的手段、受控制程度来影响地缘政治体系;跨国公司、政府、国际组织分别以投资、外交主动权、国际话语权作用于能源体系。从而形成能源和地缘政治的互动。 相似文献