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41.
Despite the importance of the socio-economic dimension of the use of marine waters, there has been little research in the field until recently, when interest has grown in the concept of ‘blue growth'. This paper aims to contribute to filling this gap with a socio-economic assessment of the main maritime sectors, focused on the Spanish part of the European Atlantic Arc. To this end, it first proposes a theoretical structure for the maritime economy and then collects and classifies comparable and reliable maritime socio-economic indicators. The data obtained allows us to assess the size of the Spanish maritime sector and the position of the Spanish Maritime Cluster in the wider context of the maritime economy of the European Atlantic, as well as discuss the appropriateness of a strategy of forming clusters at the national level vs. a transnational approach. The results indicate differences between regions in the European Atlantic Arc that complicate the development of integrated policies to stimulate blue growth. Extending our knowledge of the maritime economy of the European Atlantic Arc will make it possible to design strategies that address the real issues, increasing the likelihood of these being effective.  相似文献   
42.
To investigate climate variability in Asia during the last millennium, the spatial and temporal evolution of summer (June–July–August; JJA) temperature in eastern and south-central Asia is reconstructed using multi-proxy records and the regularized expectation maximization (RegEM) algorithm with truncated total least squares (TTLS), under a point-by-point regression (PPR) framework. The temperature index reconstructions show that the late 20th century was the warmest period in Asia over the past millennium. The temperature field reconstructions illustrate that temperatures in central, eastern, and southern China during the 11th and 13th centuries, and in western Asia during the 12th century, were significantly higher than those in other regions, and comparable to levels in the 20th century. Except for the most recent warming, all identified warm events showed distinct regional expressions and none were uniform over the entire reconstruction area. The main finding of the study is that spatial temperature patterns have, on centennial time-scales, varied greatly over the last millennium. Moreover, seven climate model simulations, from the Coupled Model Intercomparison Project Phase 5 (CMIP5), over the same region of Asia, are all consistent with the temperature index reconstruction at the 99 % confidence level. Only spatial temperature patterns extracted as the first empirical orthogonal function (EOF) from the GISS-E2-R and MPI-ESM-P model simulations are significant and consistent with the temperature field reconstruction over the past millennium in Asia at the 90 % confidence level. This indicates that both the reconstruction and the simulations depict the temporal climate variability well over the past millennium. However, the spatial simulation or reconstruction capability of climate variability over the past millennium could be still limited. For reconstruction, some grid points do not pass validation tests and reveal the need for more proxies with high temporal resolution, accurate dating, and sensitive temperature signals, especially in central Asia and before AD 1400.  相似文献   
43.
44.
Fall velocity-diameter relationships for four different snowflake types (dendrite, plate, needle, and graupel) were investigated in northeastern South Korea, and a new algorithm for classifying hydrometeors is proposed for distrometric measurements based on the new relationships. Falling ice crystals (approximately 40 000 particles) were measured with a two-dimensional video disdrometer (2DVD) during a winter experiment from 15 January to 9 April 2010. The fall velocity-diameter relationships were derived for the four types of snowflakes based on manual classification by experts using snow photos and 2DVD measurements: the coefficients (exponents) for different snowflake types were 0.82 (0.24) for dendrite, 0.74 (0.35) for plate, 1.03 (0.71) for needle, and 1.30 (0.94) for graupel, respectively. These new relationships established in the present study (PS) were compared with those from two previous studies. Hydrometeor types were classified with the derived fall velocity-diameter relationships, and the classification algorithm was evaluated using 3× 3 contingency tables for one rain-snow transition event and three snowfall events. The algorithm showed good performance for the transition event: the critical success indices (CSIs) were 0.89, 0.61 and 0.71 for snow, wet-snow and rain, respectively. For snow events, the algorithm performance for dendrite and plate (CSIs = 1.0 and 1.0, respectively) was better than for needle and graupel (CSIs = 0.67 and 0.50, respectively).  相似文献   
45.
2013年7月1日午后至夜间,华北出现一次区域性暴雨和局地大暴雨过程。局地极端降水出现在河北省邢台市宁晋县四芝兰镇,过程雨量409 mm,其中当日17—19时连续2 h雨量超过100 mm。利用常规高空和地面观测资料、NCEP再分析资料和石家庄新一代天气雷达资料,探讨了宁晋极端短时强降水的形成原因。主要结论是:(1)低槽、冷锋、副热带高压及其外围低涡切变线为其主要影响系统,海南附近台风远距离影响加强了水汽自南向北的输送,半定常的地面辐合切变线对新生对流的触发和已有对流的维持及加强起到重要作用;(2)宁晋最强降水期间,其上空具有较强的垂直风切变,有利于高度组织化的对流系统发展;(3)对流系统的后向传播使回波主体移动缓慢、持续时间长,而回波强度大和雨强很强,则导致四芝兰镇极端强降水,此外,具有弱中气旋的超级单体相对较长时间的影响使其对四芝兰镇强降水具有重要贡献;(4)产生极端降水的对流系统属于高质心发展强烈的大陆强对流型,而非更易导致强降水的低质心系统。同时,针对众多学者研究北京"7.21"特大暴雨得到的一些结论进行了进一步探讨和验证。  相似文献   
46.
The complete form of the vertical vorticity tendency equation (the complete-form vorticity equation) is derived from the Ertel potential vorticity equation to contain thermodynamic factors. In this study, a new complete-form vorticity equation, which has the same form as the original complete-form vorticity equation, is deduced from the absolute vorticity vector equation combined with the continuity equation and the expression of three-dimensional (3D) entropy gradient. By comparing the complete-form vorticity equation with the classical vertical vorticity equation, it is found that regardless of whether or not the isentropic surface is tilting, the two vorticity equations are in essence the same. The “baroclinic term” of the complete-form vorticity equation is exactly equal to the solenoidal term of the classical one, and there is a significant amount of cancellation between the two baroclinic items (the “slantwise term” and the horizontal vorticity change term) in the complete-form vorticity equation. In operational weather analysis, the tilt of the isentropic surface can be diagnosed according to the density of the isotherm on the upper-level isobaric map. For synoptic-scale motion, the vertical vorticity produced by the tilt of the isentropic surface is due to the contribution of atmospheric baroclinicity, which is measured by the solenoid. The 3D solenoid is parallel to the isentropic surface, so the more tilted the isentropic surface, the bigger the projection of the 3D solenoid in the vertical direction. The baroclinic contribution can be interpreted based on the PV thinking theory, but the relationship between the vorticity field and the potential vorticity field is not immediate.  相似文献   
47.
华北地区夏季降水模拟研究:区域气候模式性能评估   总被引:2,自引:1,他引:1       下载免费PDF全文
利用高分辨率区域气候模式Reg CM3对华北地区1991—2002年夏季气候进行了数值模拟,对照中国台站的实测资料,对模拟的华北地区夏季降水、温度进行了较为全面的比较,以检验模式的模拟性能。对平均场的模拟结果检验认为,该区域气候模式对华北地区夏季降水的空间分布模拟存在一定的误差,河套地区及黄河以南地区降水量接近实况,沿着太行山脉及东部沿海地区降水量明显偏多。模式对温度的模拟误差较小,较好地再现了气温的空间分布特征,但山西及以北地区模拟的温度略偏低。模式能够较好地模拟出华北地区夏季降水和气温的年际变化,成功再现了该区域降水和气温的异常变化。模式能够成功模拟出该区域降水和气温日变化特征,特别是对于逐年夏季的降水日变化过程的峰值和谷值均有成功表现,对于典型年份华北地区较强降水过程中降水发生的时间、落区、强度等也有再现能力,不足的是模拟的降水量比观测偏大。对于模式误差是否与地形或模式积云对流参数化方案等有关,需要进一步探讨。  相似文献   
48.
用层次分析法确定气象服务评价指标权重   总被引:5,自引:0,他引:5       下载免费PDF全文
在气象服务评价体系中,以气象服务总体评价为目标层,分层次确立一级和二级评价指标,利用2010年全国公众气象服务满意度调查中评价指标数据,应用层次分析法 (AHP) 中的9分位标度法和0.618标度法来构建判断矩阵,分析了各级评价指标的权重系数确定方法。分析发现,当评价指标少于5个时,可采用9分位标度法构建判断矩阵,以确定各评价指标的权重值;而当评价指标达到5个时,需采用0.618标度法来构建判断矩阵,计算出相应的权向量即为权重系数。将上述方法应用于2011年公众气象服务满意度调查数据中,前后两年主要评价指标对比显示,气象服务信息内容的权重在增加,而气象知识宣传普及的权重有所减小,即公众对于气象服务信息内容更为重视,同时气象部门对于公众的气象知识宣传普及工作也取得了成效。  相似文献   
49.
Concerns with the politics and practices of resource rights and access are integral to contemporary debates over environmental justice. Struggles over identity politics, especially the strategic articulation and deployment of particular identities at diverse geographical scales, have recently emerged as important mediators of justice claims in respect of resources rights, but also of recognition and procedural justice. To date, critical, multi-scalar analyses of identity-based claims for environmental justice have focused largely on the indigenous peoples’ movement. In doing so, they have failed to embrace an emergent dimension of identity-based, trans-scalar justice, namely the fledgling global pastoralists’ movement, the empirical focus for this paper. In the early years of the 21st century mobile pastoralists have begun to carve out new global spaces, through which diverse groups have attempted to negotiate common ground and forge common identities in their struggles for justice. In particular, mobile pastoralists have become increasingly visible in conservation politics and contests over land rights as they lay claim to both discursive and material ground as ‘custodians of the commons’ in an era of global climatic change. This paper draws on empirical work amongst pastoralists, NGOs and activists from Kenya, Mongolia and Spain to explore these identities, their implications for resource rights and access and the multi-scalar chains of accountability and legitimacy between global activists and their local constituents.  相似文献   
50.
A series of coupled thermo-hydraulic simulations were performed on a soil–geotextile column to understand the effect of temperature on suction distribution throughout the soil column and on the hydraulic performance of the geotextile as a drainage/capillary barrier layer. Two different constant temperatures of 0 °C and 38 °C and a temperature gradient of 4 °C along the column were modeled. Changing the temperature from 0 °C to 38 °C did not have a significant effect on the suction head distribution in the soil–geotextile column. The temperature gradient resulted in appreciable thermal vapor flow and changes in suction head and hydraulic conductivity of the geotextile. During drainage, the temperature gradient and lower temperature at the top of the column increased suction in the geotextile and its ability to function as a capillary barrier. During capillary rise, the temperature gradient and lower temperature at the top of the column decreased the suction in the geotextile and its ability to function as a capillary barrier. Changing the direction of the thermal gradient reversed the water vapor flow direction and its effect on the suction in the geotextile. A temperature gradient did not have a noticeable effect on the suction head of the geotextile when positive pore pressure was developed in the geotextile and adjacent soil during drainage.  相似文献   
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