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551.
In the last decades, the development of transport infrastructure has been necessary because of the population increase and expansion of urban centres. Infrastructure development leads to modification and changes in areas characterized by high human population density. The lack of adequate transport infrastructure inhibits local economic and social performance. In the period of economic stability (from 1970 to 1990), important roads that increased the connectedness of the Kolubara District (Western Serbia) with other parts of the country and the surrounding countries were built, but there is still a need for the construction of new roads. In order to examine the attitude of the local population in regard to transport infrastructure, a survey was conducted using a questionnaire consisting of closed questions. This topic is one that has not previously been examined. The data obtained were analyzed statistically and showed that local people have a positive attitude towards the existing infrastructure and towards the construction of new roads. There are statistically significant differences between the attitudes of the local population in different municipalities. The results from this research offer an opportunity to develop guidelines which can influence traffic development in these and similar areas.  相似文献   
552.
基于对1985—2010年间的多种历史资料和数据分析,对山东省成灾台风进行了灾害风险评估。为减少不同时期社会经济发展水平对灾害损失评估结果的影响,用标准化方法分析评估了各年的灾害损失。采用模糊数学的方法建立了综合定量指标,利用所建立的指标综合地考察了台风灾害的影响。在分析各致灾因子的作用时,将台风灾情与人文、社会要素相结合,并利用地理信息系统(GIS)平台进行了综合分析。评估结果表明,标准化的台风灾害损失情况呈逐年下降趋势,并呈现地域差异,具有明显的时空分布特征。本文研究结果可望为山东省沿海地区台风灾害的防灾减灾工作提供参考。  相似文献   
553.
Through the Upper Jurassic and Lower Cretaceous gravity-flow sandstones were deposited in the Danish Central Graben. These gravity-flow sandstones were deposited within mudstones of the Farsund Formation which is the main source rock in the area, and they are thus potential oil and gas reservoirs. The petrography and geochemistry of the sandstones show good intra well relations and several local geographical relations, which may indicate that they were derived from multiple locally sourced flows and not merely by one basin-axial flow system. The gravity-flow sandstones deposited in the eastern part of the basin are less mature and richer in, especially, carbonates and albite compared to previously deposited Jurassic sandstones and simultaneously deposited sandstones in the western part of the Danish area. This may indicate a division of the basin in an eastern and a western provenance province. This study addresses the provenance of the gravity-flow sandstones by petrographical and geochemical analyses in order to derive possible shared detrital sources as a means of understanding the transport system(s) of the gravity flows.  相似文献   
554.
555.
There is a widespread belief that poverty leads to the spread of HIV/AIDS. However, intra-country comparisons of the phenomenon have been limited. This study seeks to fill this gap by examining the relationship between poverty and HIV prevalence amongst the 10 administrative regions of Ghana. Based on the available data for poverty and HIV, certain distinct patterns emerge. For example, poverty levels are the highest in the three northern regions (Upper East, Upper West and Northern region) even though their HIV prevalence is one of the lowest. It clearly follows that there are more complex forces at work than just the effects of poverty alone. To unravel some of these puzzles, the paper proposes a key role for culture, globalization and geographical accessibility. In addition, it is suggested that local level studies in a multivariate framework have much to contribute to the identification and quantification of relevant relationships.  相似文献   
556.
水资源的优化配置是现代水资源规划和管理的重要内容,它主要解决水资源分布与生产力不相适应的问题。作者应用水资源优化配置模型,计算了在南水北调背景下,华北水资源的优化调配方案。在此方案实施的条件下,华北地区中长期的缺水问题将基本上得到解决,且经济仍能保证安全高速发展。  相似文献   
557.
甘肃沙尘暴短期、短时业务化预报方法研究   总被引:5,自引:0,他引:5       下载免费PDF全文
利用1955~2002年甘肃省80个站的观测资料,对发生在甘肃境内的64个强或特强沙尘暴个例逐个进行了天气气候分析,总结了甘肃沙尘暴天气气候特点,沙尘暴爆发的天气类型,移动路径。得出沙尘暴短期和临近预报的着眼点,建立了甘肃沙尘暴短期预报概念模型。通过用计算机语言和模块化设计方案,成功设计了中国西北地区沙尘暴监测预警人机交互预报平台,实现了沙尘暴监测预警预报业务化。  相似文献   
558.
本文将利用常规探测资料、NCEP再分析资料和多普勒雷达资料,对2018年12月29~30日铜仁市暴雪过程的环流形势特征与成因进行分析,结果表明:此次暴雪过程发生在高空南支槽、多波动槽东移、700hPa西南暖湿急流输送及850hPa东北回流冷垫的环流背景下,表现出持续时间长、范围广、强度大、积雪深的特征;强降雪阶段对流层低层有来自孟湾的源源不断的水汽输送,湿层厚度增强,且有较强的水汽辐合;700hPa较强的垂直上升运动及对流层中低层较强的垂直风切变利于暴雪天气的发生;强降雪时刻暴雪区800hPa以上位于高层冷平流、低层暖平流的叠加区域,为不稳定大气;此次降雪具有对流性和持续性特征,雷达反射率回波云团具有列车效应。  相似文献   
559.
The information acquired from Argo floats such as temperature and salinity profiles is used to study water mass properties in the Arabian Sea from 2002 to 2004. An examination of water mass structure at different locations reveals the presence of high salinity water of marginal seas in the Arabian Sea. During the southwest monsoon season, the impact of the early onset of southwesterlies is noticed in the upper ocean temperature and salinity structure over the Western Arabian Sea (WAS) during 2002. Surface density variations are found to be more during the southwest monsoon season due to strong wind forcing. Argo temperature and salinity profiles showed that the winter cooling and the formation of Arabian Sea High Salinity Water (ASHSW) over the Northern Arabian Sea (NAS) began during the second half of November within the upper 100 m depth. In the NAS, the Persian Gulf Water (PGW) salinity is above 36, as PGW moves towards the south along isopycnal layer of 26.6σθθ is potential density) salinity decreases. It is observed that the PGW high salinity water is not continuously prominent over the WAS in 2002 and in 2003. In the WAS the 27.2σθ isopycnal layer depth, corresponding to Red Sea Water (RSW), did not exactly follow the pattern of isotherms as is seen in the northern and eastern Arabian Sea. The variability related to RSW salinity is due to the underwater currents. The present study also confirms that RSW is prominent in the southeast Arabian Sea at the potential density of 27.2 with a maximum in summer monsoon compared to other seasons. The observed peak in the salinity at 27.2 density level during the spring intermonsoon is due to the influence of winter time spreading of RSW to the south of Socotra in 2002. Westward movement of Argo floats in the region east of Socotra during the winter is evident in both the observations and model studies. Water mass properties change when they move away from their source region due to the consistent horizontal advection. The changes in the water mass properties along the Argo float trajectory are confirmed by comparing with the climatological mean monthly values from the World Ocean Atlas 2001 data set.  相似文献   
560.
西宁市典型污染日PM10输送规律研究   总被引:1,自引:0,他引:1       下载免费PDF全文
为研究西宁市PM10的区域性污染特征,对2006年3月至2010年2月各季逐日大气污染指数(API,首要污染物为PM10)进行统计分析。利用后向轨迹模型(HYSPLIT Model)对西宁市典型污染日(API > 200)中气团的后向轨迹进行模拟,研究PM10的运动轨迹和区域性污染的可能来源。结果表明:西宁市一年中春季(集中于3月和4月)PM10污染严重,与该季节气团对颗粒物的长距离输送有关。造成西宁市重污染状况的主要天气是风沙尘,北部和西北部的沙漠地区是主要风沙源;相邻城市PM10污染峰值的提前与滞后,体现出区域性污染的传输过程。  相似文献   
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