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51.
Marine governance in European seas is at a crossroad aiming towards implementation of eco-system based marine management (EBMM) through integration of different EU policies or directives to protect the environment, while at the same time expected to facilitate growth and employment in support of the blue economy. This article shows that the governance landscape at the regional sea level is very complex, fragmented and faced with several dilemmas. It examines the present governance structures in the four European seas (Baltic, Black, and Mediterranean Seas and North East Atlantic Ocean). It is argued that the implementation of EBMM at the regional sea level is characterized by a highly fragmented European governance system where there is lack of coordination between relevant DGs within the European Commission, between EU, International organisations, Regional Sea Conventions and the Member States and between sectoral governance arrangements that should provide sectoral management measures that support EBMM. The article develops suggestions for a nested governance system in which institutions, policies, laws and sectors are nested into a tiered, internally consistent and mutually re-enforcing planning and decision-making system. Developing institutional interaction and soft modes of governance between the EU, the Regional Sea Conventions, Member States and the governance arrangements of the different marine sectors will be crucial in evolving towards such a nested governance system for EBMM. Moreover, there is no one size fits all approach in implementing EBMM, which means that for each European Sea a context-dependent nested governance system should be developed.  相似文献   
52.
在运用泰森多边形作边界替代得到徐州市区人口密度的分布图后,采用GCAWI法实现了徐州市区人口数据的空间化,提出了采用大小两种格网错置的平滑方法,并运用此方法得到徐州市2000年和2005年的500 m×500 m的格网人口密度分布图。结果表明:①通过对比两个年份的人口密度分布图可以发现,徐州市区人口密度在2000年~2005年期间具有南移东扩的趋势;②利用大小两种格网错置平滑的方法实现了对人口密度空间化与平滑两个功能,平滑后的结果表明,徐州市区人口密度的空间分布具有块状集聚、轴状延伸的格局,整体来看呈现出"大"字形的态势;③通过与直接运用核函数内插得到的人口密度分布图的对比可以发现,前者对反映人口密度分布的细部差异比较敏感,而后者仅能反映出人口密度空间分布的整体格局。  相似文献   
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54.
The exceptional andalusite–kyanite–andalusite sequence occurs in Al‐rich graphitic slates in a narrow pelite belt on the hangingwall of a ductile normal fault in NW Variscan Iberia. Early chiastolite is replaced by Ky–Ms–Pg aggregates, which are overgrown by pleochroic andalusite near granites intruded along the fault. Slates plot in AKFM above the chloritoid‐chlorite tie‐line. Their P–T grids are modelled with Thermocalc v2.7 and the 1998 databases in the NaKFMASH and KFMASH systems. The univariant reaction Ctd + And/Ky = St + Chl + Qtz + H2O ends at progressively lower pressure as F/FM increases and A/AFM decreases, shrinking the assemblage Cld–Ky–Chl, and opening a chlorite‐free Cld–Ky trivariant field on the low temperature reaction side. This modelling matches the observed absence of chlorite in high F/FM rocks, which is restricted to low pressure in the andalusite stability field. The P–T path deduced from modelling shows a first prograde event in the andalusite field followed by retrogression into the kyanite field, most likely coupled with a slight pressure increase. The final prograde evolution into the andalusite field can be explained by two different prograde paths. Granite intrusion caused the first prograde part of the path with andalusite growth. The subsequent thermal relaxation, together with aH2O decrease, generated the retrograde andalusite–kyanite transformation, plus chlorite consumption and chloritoid growth. This transformation could have been related to folding in the beginning, and aided later by downthrowing due to normal faulting. Heat supplied by syntectonic granite intrusion explains the isobaric part of the path in the late stages of evolution, causing the prograde andalusite growth after the assemblage St–Ky–Chl. Near postectonic granites, a prograde path with pressure decrease originated the assemblage St–And–Chl.  相似文献   
55.
地学现象的分维与标度关系——以中国大陆山系为例   总被引:2,自引:1,他引:1  
分形理论产生以后,已经在许多领域里取得了较为广泛的应用,但是在分形维数的计算方面仍存在一定的问题,最根本的问题之一是大量相关研究往往忽略了标度问题的影响,而将计算出的分维结果随意比较。本文则是以中国大陆山系为例,对地学现象的分维与标度的关系进行了研究,得出:(1)中国大陆山系的分形性质是客观存在的,其分形性质是不以测算标度而出现变化的,是始终存在的;(2)虽然在不同的测算标度下,中国大陆山系的分形性质始终是客观存在的,但是随着测算标度范围的变化,中国大陆山系的分维也会相应地出现一定的变化,即中国大陆山系客观存在的分形性质是绝对的,而分维则是一个相对的值,是随着测算标度而出现变化的;(3)分维不仅随着测算标度的变化而出现一定的变化,而且,分维是测算平均标度的函数,即D=f(r)(式中:r为测算平均标度,D为分维)关系成立;(4)因为分维值会随着不同标度范围的变化而出现相应的变化,所以,如果要进行分维之间的比较,则应选择相同的标度范围和标度值点。  相似文献   
56.
Smart electricity meters are a central feature of any future smart grid, and therefore represent a rapid and significant household energy transition, growing by our calculations from less than 23.5 million smart meters in 2010 to an estimated 729.1 million in 2019, a decadal growth rate of 3013%. What are the varying economic, governance, and energy and climate sustainability aspects associated with the diffusion of smart meters for electricity? What lessons can be learned from the ongoing rollouts of smart meters around the world? Based on an original dataset twice as comprehensive as the current state of the art, this study examines smart meter deployment across 41 national programs and 61 subnational programs that collectively target 1.49 billion installations involving 47 countries. In addition to rates of adoption and the relative influence of factors such as technology costs, we examine adoption requirements, modes of information provision, patterns of incumbency and management, behavioral changes and energy savings, emissions reductions, policies, and links to other low-carbon transitions such as energy efficiency or renewable energy. We identify numerous weak spots in the literature, notably the lack of harmonized datasets as well as inconsistent scope and quality within national cost-benefit analyses of smart meter programs. Most smart meters have a lifetime of only 20 years, leading to future challenges concerning repair, care, and waste. National-scale programs (notably China) account for a far larger number of installations than subnational ones, and national scale programs also install smart meters more affordably, i.e. with lower general costs. Finally, the transformative effect of smart meters may be oversold, and we find that smart electricity meters are a technology that is complementary, rather than disruptive or transformative, one that largely does not challenge the dominant practices and roles of electricity suppliers, firms, or network operators.  相似文献   
57.
宋袁龙  刘正军  燕琴  马广迪 《测绘科学》2013,38(5):162-163,169
本文基于点云格网化的思想,提出了一种去除机载LiDAR航带间旁向重叠区域冗余数据的算法。该算法使用规则方格表示点云覆盖的区域,通过给网格赋值的方式提取重叠区域的冗余点云,最后删除靠近条带边缘的冗余点云。经过实验测试,该方法能够快速有效地去除重叠区的冗余数据;无需依赖航迹信息,因此也适用于地面激光点云的消冗。  相似文献   
58.
北京地区雷电灾害风险评估方法与应用   总被引:4,自引:0,他引:4  
扈海波  李京校  潘进军 《气象》2012,38(8):1004-1011
首先选用北京地区1961—2008年的气候站点资料分析闪电活动的气候背景特征,用2007—2008年的闪电定位资料统计各评估网格单元的地闪密度,得到北京地区网格化地闪密度分布,评估网格单元大小为1km×1km。研究发现北京地区平均地闪密度大致在1.6~2.4次·km-2·a-1之间,有三处地闪密度的高值分布区,分别是西南部房山的拒马河流域地区,北京城中心偏北—昌平—顺义一带以及平谷一密云一带。借助空间网格技术,根据下垫面承灾体的雷电防护及规避特征,将评估区域划分成建筑物、室外建筑物遮挡部分及空旷地带三种空间类型。然后依据不同空间类型区域的地闪密度、闪电有效截收面积、雷电防护能力和位置参数等因素,分别核算评估网格单元内的雷击危险事件次数,作为雷电灾害风险评估的主要致灾因子指标。最后以人作为雷电灾害的首要承灾体,按"风险=雷击危险事件次数×暴露人口"的概念模型方法,测算北京地区雷电灾害风险指数。风险评估结果认为北京城市地区由于人口及经济实体密集分布,雷电灾害风险普遍较高,城市地区的雷电灾害风险具可规避性;农村及城市远近郊区,人口稀少,尽管闪电活动会比城市地区活跃,雷电灾害风险不是太高。  相似文献   
59.
综合考虑自动网格法和摄影测量技术各自的优缺点,提出了数字网格摄影测量法。介绍了该方法的原理与步骤,并将其应用到室内某滑坡模型试验的位移测试中。试验证明:数字网格摄影测量法可以快速、准确对模型体观测点位移进行量测,精度达到次毫米级,是一种比较理想的滑坡模型位移测试方法。  相似文献   
60.
兰州城区冬季大气污染物日变化的数值模拟   总被引:1,自引:0,他引:1  
应用嵌套网格空气质量预报模式系统(NAQPMS),模拟研究了兰州市2006年12月大气污染的日变化特征及其影响因素。在复杂地形条件下,兰州城区冬季大气污染日变化呈现白天高、夜晚低、峰值在中午的特点,NAQPMS较为合理地再现了这一特征。分析表明,在兰州冬季低风速的情况下,逆温出现频次的日变化特征与污染的日变化特征保持一致,说明逆温在冬季大气污染日变化中的作用显著。  相似文献   
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