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51.
Within the confines of Earth Observation Scientific Knowledge and Technology Transfer in Hungary (EKAT) titled ESA PECS project we gained forum for utilization of our earth observation (EO) knowledge and possibility for further development of experiences. The project aims the horizontal preparation of Hungary for ESA membership – for a dynamically developing sphere in the common part of science, technology and business. For the efficient transfer and dissemination, we preconceived target groups and principles to reach main take-up points and to open new forums of information exchange. Nowadays, user-friendly service, complex supply and real-validation process all have great importance. Joining units of suitable data choice, entire ingestion–processing chains and ergonomic interfaces can only offer a timely and professional solution for the challenges of industry and business sectors. It has to be clearly seen, that information and communication technologies (ICT) and information control becomes a more and more significant part of EO services. 相似文献
52.
精密控制网测量中,气象因素对边长精度的影响不容忽视.文章针对测量机器人的主要误差来源,对影响精密控制网测量精度的主要因素进行分析:剖析了自动目标识别(ATR)的主要误差源,指出了ATR观测中应选择最佳观测条件以保证角度测量精度;结合实测数据详细分析了温度、气压、折光系数K对边长改正精度的影响,提出了在高精度测量中应精确测定气象因子和选择最佳观测时段测量的思路,并提出了利用三角高程网平差后高差求解各方向动态K值进行边长改正的方法,可有效提高边长改正的精度.最后实例验证了这些措施的可行性. 相似文献
53.
54.
球谐函数变换快速计算扰动引力 总被引:1,自引:0,他引:1
在球谐函数变换基础上,利用新极下轨道的特殊性,在新坐标下引入Clenshaw求和计算轨道扰动引力。从理论上对比分析了传统方法、球谐函数变换方法和改进方法的计算速度和存储模型需要的物理空间。模拟试验分别采用3种方法计算了一段轨道的扰动引力,试验结果表明,改进的球谐函数变换方法比传统球谐函数变换方法计算速度可提高100倍,数据存储量仅占传统方法的3%。 相似文献
55.
Wu Hong 《地球空间信息科学学报》2013,16(3):34-41
Temporal geographic information system (t-GIS) is a kind of computer information system that can display, process and analyze the micro-format distribution of temporalspatial information of real world. It includes both spatial geographic information and temporal information, and can analyze both the static geographic information and the dynamic geographic information. 相似文献
56.
《International Journal of Digital Earth》2013,6(1):78-90
Abstract Information of snow cover (SC) over Himalayan regions is very important for regional climatological and hydrological studies. Precise monitoring of SC in the Himalayan region is essential for water supply to hydropower stations, irrigation requirements, and flood forecasting. Microwave remote sensing has all weather, day and night earth observation capability unlike optical remote sensing. In this study, spaceborne synthetic aperture radar interferometric (InSAR) coherence analysis is used to monitor SC over Himalayan rugged terrain. The feasibility of monitoring SC using synthetic aperture radar (SAR) interferometry depends on the ability to maintain coherence over InSAR pair acquisition time interval. ERS-1/2 InSAR coherence and ENVISAT ASAR InSAR coherence images are analyzed for SC mapping. Data sets of winter and of snow free months of the Himalayan region are taken for interferogram generation. Coherence images of the available data sets show maximum decorrelation in most of the area which indicates massive snowfall in the region in the winter season and melting in the summer. Area showing coherence loss due to decorrelation is mapped as a snow-covered area. The result is validated with field observations of snow depth and it is found that standing snow is inversely related to coherence in the Himalayan region. 相似文献
57.
《International Journal of Digital Earth》2013,6(4):356-371
Abstract Administrative units reflect the territorial hierarchies established within all countries of the world. The units are addressable with geocodes that provide a bijective mapping between territories and unique identification codes. Early warning systems for natural or man-made hazards often map affected or threatened areas to administrative units to establish a spatial reference that is comprehensible to all parts of the population. Addressing these territories in an international context has several requirements, such as worldwide coverage, completeness and topicality, which must be met by geocode standards. In this paper, the practicability and suitability of international geocode standards are examined in the context of the requirements of large-scale early warning systems. This paper exposes the insufficiencies and limitations of existing geocode standards International Organization for Standardization (ISO)-3166, Second Administrative Level Boundaries data set project (SALB) and Nomenclature of the Territorial Units for Statistics (NUTS) and emphasises the suitability of the non-official hierarchical administrative subdivision codes (HASC). The analysis is framed in the context of addressing affected areas for an Indian Ocean tsunami early warning system. This system was developed within the Distant Early Warning Systems project according to the requirements of the United Nations Educational, Scientific and Cultural Organization (UNESCO) Intergovernmental Oceanic Commission for Regional Tsunami Watch Providers (RTWPs). 相似文献
58.
《International Journal of Digital Earth》2013,6(6):461-487
Abstract Currently, many soil erosion studies at local, regional, national or continental scale use models based on the USLE-family approaches. Applications of these models pay little attention to seasonal changes, despite evidence in the literature which suggests that erosion risk may change rapidly according to intra-annual rainfall figures and vegetation phenology. This paper emphasises the aspect of seasonality in soil erosion mapping by using month-step rainfall erosivity data and biophysical time series data derived from remote-sensing. The latter, together with other existing pan-European geo-databases sets the basis for a functional pan-European service for soil erosion monitoring at a scale of 1:500,000. This potential service has led to the establishment of a new modelling approach (called the G2 model) based on the inheritance of USLE-family models. The G2 model proposes innovative techniques for the estimation of vegetation and protection factors. The model has been applied in a 14,500 km2 study area in SE Europe covering a major part of the basin of the cross-border river, Strymonas. Model results were verified with erosion and sedimentation figures from previous research. The study confirmed that monthly erosion mapping would identify the critical months and would allow erosion figures to be linked to specific land uses. 相似文献
59.
A long-term Global LAnd Surface Satellite (GLASS) data-set for environmental studies 总被引:1,自引:0,他引:1
《International Journal of Digital Earth》2013,6(6):5-33
Recently, five Global LAnd Surface Satellite (GLASS) products have been released: leaf area index (LAI), shortwave broadband albedo, longwave broadband emissivity, incident short radiation, and photosynthetically active radiation (PAR). The first three products cover the years 1982–2012 (LAI) and 1981–2010 (albedo and emissivity) at 1–5 km and 8-day resolutions, and the last two radiation products span the period 2008–2010 at 5 km and 3-h resolutions. These products have been evaluated and validated, and the preliminary results indicate that they are of higher quality and accuracy than the existing products. In particular, the first three products have much longer time series, and are therefore highly suitable for various environmental studies. This paper outlines the algorithms, product characteristics, preliminary validation results, potential applications and some examples of initial analysis of these products. 相似文献
60.
《International Journal of Digital Earth》2013,6(6):582-603
ABSTRACTPublic understanding of climate and climate change is of broad societal importance. However, misconceptions regarding reasons for the seasons abound amongst students, teachers, and the public, many of whom believe that seasonality is caused by large variations in Earth’s distance from the Sun. Misconceptions may be reinforced by textbook illustrations that exaggerate eccentricity or show an inclined view of Earth’s near-circular orbit. Textbook explanations that omit multiple factors influencing seasons, that do not mesh with students’ experiences, or that are erroneous, hinder scientifically valid reasoning. Studies show that many teachers share their students’ misconceptions, and even when they understand basic concepts, teachers may fail to appreciate the range of factors contributing to seasonal change, or their relative importance. We have therefore developed a learning resource using Google Earth, a virtual globe with other useful, weather- and climate-related visualizations. A classroom test of 27 undergraduates in a public research university showed that 15 improved their test scores after the Google Earth-based laboratory class, whereas 5 disimproved. Mean correct answers rose from 4.7/10 to 6/10, giving a paired t-test value of 0.21. After using Google Earth, students are helped to segue to a heliocentric view. 相似文献