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961.
西双版纳土地利用/覆盖格局的热环境效应研究   总被引:1,自引:0,他引:1  
利用Landsat TM/ETM+数据的热红外波段,通过单通道算法,反演了中国热带西双版纳地区的地表温度,并对西双版纳地表温度演变的规律进行了分析,结果显示:(1)研究期间,西双版纳土地利用/覆盖发生了剧烈变化,有林地面积不断减少,旱地、灌木林、茶园与橡胶园面积不断增加;(2)旱地、荒草地、茶园、建设用地的地表真实温度的平均值较高,水体和有林地的平均温度较低;(3)旱地、灌木林、有林地、荒草地和橡胶园对区域的热效应贡献较大,水体、水浇地、建设用地、滩涂和水体的热效应贡献较小;有林地的热单元权重有不断减少的趋势,灌木林与旱地的热单元权重有不断增加的趋势;(4)西双版纳土地利用/覆盖的剧烈变化改变了区域地表温度的分布格局,最终可能会导致地方气候变化。需要进一步开展西双版纳地区LUCC—气候—生态系统耦合研究,深入研究区域LUCC特别是橡胶园的时空变化过程及其气候/生态效应、气候变化与LUCC过程的互馈机制,为实现区域可持续发展提供科学依据。  相似文献   
962.
运用树木年代学的基本原理和方法,研究三明地区马尾松(Pinus massiniana)径向生长对气候要素的响应。结果表明:夏季温度限制着马尾松的径向生长,年轮宽度与上一年和当年7—8月平均气温均呈显著负相关(P0.01);马尾松的径向生长受到降水和湿度的影响较大,与上一年1—3月降水量和2—3月平均相对湿度显著负相关(P0.01),与当年6—11月平均降水量和7—8月相对湿度显著正相关(P0.01);同时宽度年表与上一年2—3月太阳日照时数显著正相关(P0.01);另外,宽度年表与6—11月PDSI显著正相关(P0.05),生长季的干旱胁迫抑制了马尾松的生长。研究说明本地区限制马尾松树木生长的因素较多,1年中不同时期限制马尾松径向生长的气候因子不同。  相似文献   
963.
Agro-meteorological disasters(AMD) have become more frequent with climate warming. In this study, the temporal and spatial changes in the occurrence frequency of major meteorological disasters on wheat production were firstly explored by analyzing the observed records at national agro-meteorological stations(AMS) of China from 1991 to 2009. Furthermore, impact of climate change on AMD was discussed by comparing the warmer decade(2000–2009) with another decade(1991–2000). It was found that drought was the most frequent disaster during the last two decades, with a highest proportion of 79%. And the frequency of AMD increased significantly with climate change. Specifically, the main disasters occurred more frequently in the reproductive period than in the vegetative period. Besides, the spatial changes in the AMD frequency were characterized by region-specific. For example, the wheat cultivation areas located on the Loess Plateau and the middle-lower reaches of the Yellow River suffered mainly from drought. All these results were strongly linked to climate change in China. Therefore, sound adaptation options should be taken based on the latest changes of AMD under global warming to reduce agricultural damages.  相似文献   
964.
一致性假设一直是洪水频率分析的基本假设条件,但在气候变化与人类活动综合影响下,水文极值序列的一致性假设受到极大挑战。基于此,以东江流域为例,运用GAMLSS模型(广义可加模型),将时间、气候指标(北极涛动AO、北太平洋涛动NPO、太平洋年代际振荡PDO和南方涛动SOI)以及水库指标(Reservoir Index)统一纳入洪水频率分析中,并对东江流域1954―2009年年最大流量序列(AMS)进行频率分析,结果表明:1)龙川、河源和岭下站年最大流量序列均值与时间呈线性关系,方差为常量,而博罗站均值和方差与时间均呈非线性关系;2)水库对各水文站点AMS均值有显著线性影响;3)NPO对各站点AMS均值有显著线性影响,NPO值较高时,东江流域可能面临着较低的洪水风险,在一致性假设前提下,可能高估洪水设计值,反之亦然;而PDO对各站点方差有显著线性(岭下、博罗)/非线性(龙川、河源)影响;4)以时间为协变量构建非一致性模型,研究得出:龙川、河源和岭下3站T年一遇洪水设计值均呈单调下降趋势,博罗站1954―1995年左右洪水设计值呈下降趋势,而在1996―2009年呈上升趋势;以气候与水库为协变量构建非一致性模型,研究表明:龙川、河源和岭下3站T年一遇洪水设计值均因水库影响呈向下跃变;5)以气候和水库为协变量的非一致性模型对洪水频率具有良好的预测能力,为非一致条件下设计洪水的预测提供了新的预测方法。  相似文献   
965.
One main argument for modeling socio-ecological systems is to advance the understanding of dynamic correlations between various human and environmental factors, including impacts and responses to environmental change. We explore the shift in skier distribution among ski resorts taking into account the behavioral adaptation of individuals due to the impact of climate change on snow conditions. This analysis is performed at a regional scale by means of a coupled gravity and georeferenced agent-based model. Four different scenarios are considered. Two scenarios assume an increase of winter mean temperature of +2°C and +4°C, respectively, taking into account only natural snow conditions. Two additional scenarios add the effect of snowmaking to enhance the natural snow depth and extend the skiing season in the +2°C and +4°C base scenarios. Results show differing vulnerability levels, allowing the classification of ski resorts into three distinct groups: (1) highly vulnerable ski resorts with a strong reduction in visitors attendance for all climate change scenarios, characterized by unfavorable geographical and attractiveness conditions, making it difficult to ensure snow availability in the future; (2) low vulnerability ski resorts, with moderate reduction in season length during a high climate change scenario but no reduction (or even an increase) in a low one, characterized by ski resorts with a medium capacity and attractiveness to ensure enough snow conditions and capture skiers from other ski resorts; and (3) resilient ski resorts, with good conditions to ensure future snow-reliable seasons and outstanding attractiveness, allowing them to offer longer ski seasons than their competitors and potentially attracting skiers from other closed or marginal resorts. Ski resorts included in this last group increase their skier attendance in all climate change scenarios. Although similar studies in the literature foretell a significant reduction of the ski market in the near future, another probable effect outlined in this study is a redefinition of this market due to a redistribution of skiers, from vulnerable ski resorts to more resilient ones.  相似文献   
966.
Using NCEP/NCAR reanalysis data and the sand-storm frequency data fi'om 37 weather stations in the Tarim Basin for the period 1961-2009, the relationship between the frequency of spring sandstorms in the Tafim Basin and the associated atmospheric circu- lation pattems is analyzed in this study. We found significantly negative correlations between sandstorm frequency and the 500-hPa geopotential height over the Paris Basin and midwestem Mongolia, while there were positive correlations over the Ural River region. The rising of the 500-hPa geopotential height in midwestem Mongolia and its falling over the Ural region corre- spond to a weakening of the large-scale wave patterns in the Eurasian region, which directly causes the frequency of the sand-dust storms in the Tarim Basin to decline. Also, the abrupt decline in the spring sandstorm frequency in the Tarim Basin observed in the last half-century is associated with profound changes in the atmospheric circulation in these key regions. At the interannual scale, the strengthened cyclonic atmospheric circulation patterns in the western part of Mongolia and the anticyclonic patterns over the East European plains at 500-hPa geopotential height, are responsible for frequent sandstorm occurrences in the Tarim Basin.  相似文献   
967.
Global climate warming which began in the second half of the twentieth century is continuing. It is associated with increased risks for ecological management, especially in permafrost areas comprising over 65% of Russia. Of special concern are dams constructed on permafrost. They are subject not only to climatic impacts, but also to additional hydrothermal loads from water reservoirs. This paper presents the concept of geocryological monitoring of dams and other water resource projects and substantiates its necessity in view of climatic change. It also presents methods, scope and implementation of geocryological monitoring at medium and small dams, considering the specific nature of Far Northern areas, as well as the complicated geotechnical, hydrogeological and permafrost conditions.  相似文献   
968.
Climate changes at the multi-decadal scale are often associated with multi-decadal phase shifts of the dominant sea surface temperature (SST) pattern, such as the Pacific Decadal Oscillation (PDO). The PDO may be associated with the North Pacific branch of the Thermohaline Circulation (THC). Great earthquakes (M 〉8), particularly along the route of the THC, might modulate the vertical mixing and bring deep, cold water to surface, contributing to multi-decadal changes in surface currents and the PDO. This may eventually lead to multi-decadal climate changes. We tested this hypothesis for the Pacific Ocean where great earthquakes have been frequently recorded. We found associations between the PDO and recurrent earthquakes along the route of the deep currents of the THC in the modern period since 1900, and relationships between hydroclimate change in Monsoonal Asia and historical earthquakes since 1300. However, it should be noted that this hypothesis is very preliminary and has many gaps that needs further evidences from more observational records and modeling studies.  相似文献   
969.
Global climate change has evolved from a scientific problem into an economic and political problem oI worlOwloe rater- est. National perspectives play a crucial role in addressing climate change. Mutual understanding of perspectives is nec- essary to result in rational policies and a consensus among stakeholders with divergent interests. Conceptual frameworks for understanding the problem of climate change in China, the largest developing country and the largest greenhouse gas emitter, are of great significance to national and international efforts to address the problems of climate change. Chinese perceptions of climate change as a sustainable development problem have recently been in tension with an emerging Western perspective that frames climate change as a security issue. This paper explores Chinese perceptions of climate change as expressed in recent governmental policy statements, public opinion surveys, and academic scholarship with a focus on publications in Chinese-language journals, often unfamiliar in the West. It looks at the relationship between Chinese research and policy and finds that the Chinese policy frame of climate change as a sustainable development problem draws from the body of domestic research and is reflective of the perspectives and multidisciplinary approach of Chinese researchers in areas of climate change.  相似文献   
970.
利用信江流域梅港水文控制站1953—2011年径流量观测资料和11个气象站同期气象观测资料,采用统计方法、Mann-Kendall非参数检验方法、Morlet小波分析法,对信江流域径流量年内、年际变化的不均匀性、长期趋势、周期变化,及其与气候因素的相关性等进行分析。结果显示,信江流域多年平均径流量呈缓慢增大趋势,但具有显著的年际和年代际变化特征,振荡周期明显,年际变化的主要周期为6—8 a,年代际变化的主要周期为准22 a,在20世纪70—90年代最明显。年流量以主汛期(4—6月)为最多,春、夏季(3—8月)径流变差系数小,水量稳定,冬季变差系数大,水量不稳定。流域径流量与气候因素中的降水、蒸发具有显著的相关性,而人类活动中的城镇化、经济、人口等因素对径流变化起到了一定的辅助作用。  相似文献   
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