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131.
京珠高速公路粤境北段路堑高边坡失稳防治研究 总被引:1,自引:0,他引:1
京珠高速公路粤境北段地形条件十分复杂,被世界银行专家称为“中国最具挑战性的公路项目”。文章介绍了针对此项目开展的路堑高边坡失稳防治研究情况,着重介绍了该项研究的技术路线,以及为预防路堑高边坡失稳开展的系列研究。即:①路堑高边坡工程地质条件;②按常规所做原设计的堑坡稳定性;③路堑高边坡设计方案;④路堑高边坡施工工艺;⑤动态监测;⑥动态设计。研究与设计施工密切配合,及时将研究成果应用到工程实践中,取得很好的效果。 相似文献
132.
Environmental justice is the principle that environmental costs and amenities ought to be equitably distributed within society. Due to the ethical, political, and public–health implications, and because many choices confront those researching environmental justice, standardized measures are needed to inform public dialogue and policy. We develop and test seven indices on three Colorado cities to measure the relationship between the distribution of environmental hazards and minority and poverty–stricken populations, and recommend the Comparative Environmental Risk Index as a preliminary, standardized measure for comparing urban areas. This index is particularly relevant to disadvantaged communities, regional planning organizations, environmental–justice networks and scholars, and state and federal agencies. 相似文献
133.
玉米市场空间关联是反映玉米市场运行效率的关键指标,价格支持政策的实施及改革对玉米市场空间关联产生重要影响。本文基于中国省际玉米市场价格数据,分析了价格支持政策改革背景下玉米市场空间关联及其时变情况,并运用社会网络分析法刻画了玉米市场空间关联网络特征,最后,通过QAP分析考察了影响玉米市场空间关联的主要因素。研究发现:① 中国玉米市场总体空间关联程度较高,且近年来整体呈上升趋势,玉米临时收储政策的实施并未改变其上升趋势,但导致政策实施省份玉米市场与其他地区玉米市场间关联程度下降。② 玉米市场空间关联呈现多线程、复杂的网络结构形态,网络结构较为紧密、整体关联性强且较为稳定;中东部地区玉米消费量较大的省份在玉米市场空间关联网络中处于中心位置,在网络中扮演着中心行动者角色,而实施玉米支持政策的区域以及西部地区在玉米市场空间关联网络中影响力较小,处于边缘和弱势地位,扮演着边缘行动者角色。③ 地理位置邻接、市场距离、销区市场势力、信息传递效应以及实施临时收储政策是决定和影响玉米市场空间关联的主要因素,其中,销区市场势力及信息传递效应对玉米市场空间关联的影响不断上升。 相似文献
134.
Susan S. Fainstein 《Urban geography》2018,39(8):1268-1275
New York City has developed recent policy initiatives under the rubric of resilience. I consider the implications of extending the concept of resilience beyond the physical environment, analyze the effect of planning for adaptation rather than prevention, and finally examine the positive role played by community groups organized for environmental justice in responding to resiliency planning. My argument is that use of the term resilience tends to obscure distributional impacts and, even under a progressive mayor, supports neoliberal policy initiatives. 相似文献
135.
136.
Non-profit organizations are key actors in urban and community forestry (UCF) initiatives, and sometimes city residents resist their efforts. Between 2011-2014, 24 percent of residents offered a street tree in Detroit, Michigan, USA submitted a “no-tree request.” Differing views on decision-making emerged as a main reason for resistance to tree planting. This study used interviews with city residents, and those within a non-profit organization, between 2014-2016 to understand reasons for conflict over decision-making between these groups. Heritage narratives, or selective representations of the city’s history and character, helped explain conflict over tree planting. Residents who wanted greater decision-making power in tree planting assumed they would be responsible for stewardship, reflecting their historical experiences within the city. The organization’s dominant heritage narrative emphasized that residents held misperceptions of trees based on negative past experiences, and required education on benefits of trees. Recommendations for integrating heritage narratives into UCF efforts are provided. 相似文献
137.
The present study describes a novel way of a systematic and objective selection procedure for the development of an Artificial Neural Network-based storm Surge Forecast Model (ANN-SFM) with the 5, 12 and 24 h-lead times and its application to Sakai Minato area on the Tottori coast, Japan. The selection procedure guides how to determine the superiority of the best performing model in terms of the appropriate combination of unit number in the hidden layer and parameter in the input layer. In the application of ANN-SFM to Sakai Minato, it is found that the best 5 and 12 h-forecast ANN-SFMs are established with the most suitable set of 70 units (the number of hidden neurons) and the input components of surge level, sea level pressure, the depression rate of sea level pressure, longitude, latitude, central atmospheric pressure and highest wind speed. The best 24 h-forecast ANN-SFM is determined with 160 units and the input parameters of surge level, sea level pressure, the depression rate of sea level pressure, longitude and latitude. The proposed method of the selection procedure is able to be adaptable to other coastal locations for the development of the artificial neural network-based storm surge forecast model as establishing the superiority of the most relevant set combining unit numbers and input parameters. 相似文献
138.
Recovering seismic information contained in old analog records could increase our knowledge of seismic source characteristics and the seismicity of a region. This is particularly important in zones with low to moderate seismicity.To extract the available information, it is necessary to digitize the seismic records. This is not an easy task especially owing to the generally poor quality of the original records, with illegible or missing parts. However some exceptions were found in the records of a few seismological stations in Germany, Sweden and France.This paper presents an example of the recovering of source parameters and can be divided in two parts: the first one presents a simple semi-automatic technique for digitization of old analog seismic records, developed using commercial software on a PC; the second part describes the methodology of assessing the seismic moment, using empirical and theoretical relations, as well as the seismic source dimensions.The earthquake selected to illustrate this procedure is the 23 April 1909 Benavente (Portugal) earthquake. This earthquake occurred in the Lower Tagus Valley region and caused great destruction in the meizoseismal area. It is the biggest earthquake that occurred during this century in the central part of the country and its magnitude has been estimated between 6.6 and 7.6.The digitization procedure allowed the recovery of seismic information contained in old analog records, in particular, the seismic moment estimation. The results obtained indicated that 7.6 was a very high value for the magnitude of the 23 April 1909 earthquake, suggesting that the magnitude reported in the Portuguese catalogue is overestimated. The estimated moment magnitude is 6.0. 相似文献
139.
Peng Gao Pengfei Li Baili Zhao Ruirui Xu Guangju Zhao Wenyi Sun Xingmin Mu 《水文研究》2017,31(26):4639-4646
Environmental change resulting from intensified human interventions and climate change has impacted the hydrological function of many large river systems, largely altering the production and transport of run‐off and sediment. It is thus vital to quantitatively evaluate the influence of climate change and human activities on streamflow and sediment discharge. Water balance equations, hydrological models, and comparative analyses are commonly used to fulfil this need. Double mass curves (DMCs), being one useful method for comparative analyses, are characterized by low data requirements and high transferability, and thus more practical than water balance equations and hydrological models for hydrologic benefit evaluations. However, the detailed derivation procedure of the DMC has, to date, yet been described in literature. Moreover, in previous studies, changing points of the DMC were determined either rather empirically or as the changing point of streamflow or sediment discharge (i.e., precipitation was not considered). Hence, the changing point detected may be subject to inaccuracies. This paper, for the first time, comprehensively detailed the derivation procedure of the DMC; a new way was proposed to quantitatively examine the changing point of the DMC; an example was also given to demonstrate the use of the DMC in the hydrologic benefit evaluation. It is hopeful that the method given in our paper will be widely adopted by future studies as a standard procedure to derive and use the DMC. 相似文献
140.