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811.
Holth TF Beckius J Zorita I Cajaraville MP Hylland K 《Marine environmental research》2011,72(3):127-134
There is a need for sensitive biological effect methods by which to detect impacts of chronic exposure to low concentrations of contaminants. Two methods shown to be potentially useful for monitoring purposes in fish include lysosomal membrane stability and peroxisome proliferation. These biological endpoints were assessed in Atlantic cod (Gadus morhua) head kidney following exposure to a mixture of produced water components including polycyclic aromatic hydrocarbons, phenol, and alkylphenols. Lysosomal damage of head kidney cells occurred within the first two weeks and did not recover during the entire exposure period (32 weeks). Lysosomal membrane stability was not affected by gender and was responsive at low concentrations of contamination, indicating that lysosomal membrane stability measured in the head kidney could be a useful biomarker for effects of offshore pollution. Peroxisome proliferation, measured as acyl-CoA oxidase activity in the head kidney, appeared to be a potential biomarker in male cod exposed less than 16 weeks. 相似文献
812.
Many breakwaters are, due to functional requirements, designed for small wave overtopping discharges. From the EC-research projects OPTICREST and CLASH it is known that overtopping discharges determined from conventional Froude scale models of rubble mound breakwaters are smaller than measured in corresponding prototypes. The present study examines this scale effect by comparing overtopping discharges in small scale and large scale tests. The length scale ratio between the models was 5.7. 相似文献
813.
???GRACE?????л??????????????????????????????????????????ò?????????????????????????????????????????????????????????????????????????????????????????????????????Ч??????? 相似文献
814.
815.
As climate change intensifies, the need for large-scale transformations that reform vulnerable systems’ prevailing values and development pathways is increasingly recognized. However, there is limited understanding of the factors that underlie such changes. This study sheds light on these factors by examining the case of Israel – a largely arid to semi-arid country with highly scarce natural water resources and a historical rural-agricultural ideology. Adopting an historically-informed systems perspective, I analyze two transformations that diminished Israel’s vulnerability to recurring droughts: the 1960s’ economic transformation from agriculture to industry, and the shift to seawater desalination in the mid-2000s. These changes are examined using causal-loop diagrams based on multiple data sources, including archival records, statistical reports and a systematic review of grey and academic literature.The findings show that both transformations, instigated by state institutions during exceptionally severe droughts, were driven by shifts away from development paradigms embedded in the nation-building ideology, as well as by social stresses that exceeded the natural limits of the agricultural system and water supply system. Repeated drought shocks activated and later reactivated the shift to desalination, intended to a certain degree to reduce drought vulnerability. However, drought did not significantly affect the economic transformation, initiated mainly due to saturation in agricultural development. Thus, I argue that alongside concerted adaptation efforts state institutions should dedicate greater attention to the management of broader social challenges and crises in a manner that fosters greater resilience against future climate changes. Ideological shifts and consequent restructuring of development paths, as well as the interaction between population growth and limited natural resources, may constitute important entry points. These entry points are particularly pertinent to emerging economies in other dry areas, many of which face similar social and economic trends to those experienced in Israel over the last decades. 相似文献
816.
气候风险可能给人类社会带来巨大的生命和财产损失,气候保险通过转移分散风险成为应对气候风险的有效机制。文中首先在辨析气候保险的概念和市场机制等理论基础上,分析了气候保险存在逆向选择风险与难以满足大数法则、存在道德风险与反馈效应的问题;其次梳理了发达国家气候保险的发展情况,其风险分散和转移功能比较强,保费一部分存在政府补贴,一般采取政府紧急贷款、再保险和保险衍生品的方式进一步分散风险,但是也存在道德风险的问题。最后分析了中国气候保险的发展现状发现存在着难以满足大数法则的问题,道德风险尚无明确体现,并提出建议:完善气象站基础设施、制定自然灾害风险地图、提高公众和敏感行业气候保险的购买意愿等尽量使气候保险满足大数法则;促使保险公司在设计保险产品时考虑非经济成本,未雨绸缪避免道德风险及反馈效应;适时发展气候再保险和保险衍生品,建立分散和转移风险的市场机制。 相似文献
817.
IPCC《气候变化与土地特别报告》对陆气相互作用的新认知 总被引:2,自引:0,他引:2
贾根锁 《气候变化研究进展》2020,16(1):9-16
IPCC向全球正式发布了其最新的《气候变化与土地特别报告》(SRCCL),从陆气相互作用、荒漠化、土地退化、粮食安全、综合变化和协同性、可持续土地管理等方面评估气候变化与土地的相互关联。报告是在IPCC 3个工作组共同主导下,首次系统评估气候变化与陆面过程和土地利用/土地管理之间的相关作用。报告的评估结果表明,全球陆地增温幅度接近全球海陆平均值的两倍,气候变化加重了综合土地压力,并严重影响全球粮食安全,而全球很多区域的极端天气气候事件频率/强度持续增加,加重了农业生产的灾害风险和损失。采取行业间和国家间协同一致的行动,通过可持续土地管理,可以有效地适应和减缓气候变化,同时减轻土地退化、荒漠化和粮食安全的压力。 相似文献
818.
AbstractThe National Drought Model (NDM) is an amalgamation of the atmospheric component of the original Palmer Drought and Versatile Soil Moisture Budget (VSMB) models. The NDM uses locally derived coefficients from the station or gridded climate data to calculate a calibration factor for comparing locations in time and space. A modular approach is used to model major processes such as evapotranspiration, biometeorological time, snowmelt, and the cascading of soil moisture down to the root zone. The modular approach allows modifications to be made to specific sections without making structural changes to the entire model or the data inputs. The NDM is an operational tool, integrating data from the climate, soil, and plant sciences to monitor agroclimatic risks such as drought and excess moisture. In this paper, the capacity of the NDM to monitor extreme agroclimatic risks, such as drought and flooding of agricultural soils, was assessed. Using the Palmer Drought Severity Index component of the NDM, the mapping of the spatial extent and severity of the 2001 and 2002 droughts across Canada and the excess moisture conditions on the Canadian Prairies in 2010 agreed with other assessments. The validation study of soil moisture at two Alberta locations (Lethbridge and Beaverlodge) showed that the VSMB tracked the soil moisture flux in the root zone successfully in response to changing environmental conditions. The VSMB explained about 70 and 60% of the variance in observed soil moisture at the two respective locations. 相似文献
819.
Australia's vulnerability to climate variability and change has been highlighted by the recent drought (i.e. the Big Dry or Millennium Drought), and also recent flooding across much of eastern Australia during 2011 and 2012. There is also the possibility that the frequency, intensity and duration of droughts may increase due to anthropogenic climate change, stressing the need for robust drought adaptation strategies. This study investigates the socio-economic impacts of drought, past and present drought adaptation measures, and the future adaptation strategies required to deal with projected impacts of climate change. The qualitative analysis presented records the actual experiences of drought and other climatic extremes and helps advance knowledge of how best to respond and adapt to such conditions, and how this might vary between different locations, sectors and communities. It was found that more effort is needed to address the changing environment and climate, by shifting from notions of ‘drought-as-crisis’ towards acknowledging the variable availability of water and that multi-year droughts should not be unexpected, and may even become more frequent. Action should also be taken to revalue the farming enterprise as critical to our environmental, economic and cultural well-being and there was also strong consensus that the value of water should be recognised in a more meaningful way (i.e. not just in economic terms). Finally, across the diverse stakeholders involved in the research, one point was consistently reiterated: that ‘it's not just drought’. Exacerbating the issues of climate impacts on water security and supply is the complexity of the agriculture industry, global economics (in particular global markets and the recent/ongoing global financial crisis), and demographic changes (decreasing and ageing populations) which are currently occurring across most rural communities. The social and economic issues facing rural communities are not just a product of drought or climate change – to understand them as such would underestimate the extent of the problems and inhibit the ability to coordinate the holistic, cross-agency approach needed for successful climate change adaptation in rural communities. 相似文献
820.
In arid lands, food resources and predation risk become major decision factors in mule deer habitat use. We examined variables related to these two factors that might determine mule deer (Odocoileus hemionus) habitat use in a warm desert at two spatial scales: the macro-habitat scale, which relates to home range decisions, and the micro-habitat scale, which relates to decisions made during foraging. Our prediction was that habitat use should primarily be explained by food variables and, to a lesser degree, by variables related to predation risk by pumas (Puma concolor). We mapped all deer pellet groups in 72, 1 ha quadrats in the Mapimí Biosphere Reserve and measured food and habitat variables over two years with different precipitation amounts. The area was used more intensively during the dry year. Under drier conditions, deer habitat use was explained primarily by food resource variables and secondarily by variables related with predation risk. During the wetter year, food resources became unimportant while cover and visibility explained deer habitat use. The data suggest that the tradeoffs deer are willing to make between food resources and predation risk in an arid environment are strongly affected by food resource levels, as influenced by precipitation. 相似文献