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91.
提出利用多项式拟合模板法消除地震数据中的低频随机干扰,分析模板的性质并推导出模板参数与低频随机干扰最高频率之间的关系式。  相似文献   
92.
ABSTRACT

In many places, magnitudes and frequencies of floods are expected to increase due to climate change. To understand these changes better, trend analyses of historical data are helpful. However, traditional trend analyses do not address issues related to shifts in the relative contributions of rainfall versus snowmelt floods, or in the frequency of a particular flood type. We present a novel approach for quantifying such trends in time series of floods using a fuzzy decision tree for event classification and applied it to maximal annual and seasonal floods in 27 alpine catchments for the period 1980–2014. Trends in flood types were studied with Sen’s slope and double mass curves. Our results reveal a decreasing number of rain-on-snow and an increasing number of short rainfall events in all catchments, with flash floods increasing in smaller catchments. Overall, the results demonstrate the value of incorporating a fuzzy flood-type classification into flood trend analyses.  相似文献   
93.
ABSTRACT

This study aimed to evaluate the potential of the recently introduced Prophet model for estimating reference evapotranspiration (ETo). A comparative study was conducted for benchmarking the model results with support vector regression (SVR) and temperature-based empirical models (Thornthwaite and Hargreaves) in southern Japan. The performance of the Prophet, SVR and temperature-based empirical models was evaluated by Nash–Sutcliffe efficiency (NSE) and coefficient of determination (R2). The results indicate that temperature-based Prophet and SVR models have greater accuracy than the empirical models. The Prophet model with sole input of relative humidity, sunshine hours or windspeed showed acceptable accuracy (NSE > 0.80; R2 > 0.80), while SVR models with similar inputs showed greater errors. Accuracy improved with increasing number of input parameters, giving excellent performance (NSE > 0.95; R2 > 0.95) with all input parameters. Hence, the Prophet model is a new promising approach for modelling ETo with limited input variables.  相似文献   
94.
ABSTRACT

For evaluating the progresses towards achieving the Sustainable Development Goals (SDGs), a global indicator framework was developed by the UN Inter-Agency and Expert Group on Sustainable Development Goals Indicators. In this paper, we propose an improved methodology and a set of workflows for calculating SDGs indicators. The main improvements consist of using moderate and high spatial resolution satellite data and state-of-the-art deep learning methodology for land cover classification and for assessing land productivity. Within the European Network for Observing our Changing Planet (ERA-PLANET), three SDGs indicators are calculated. In this research, harmonized Landsat and Sentinel-2 data are analyzed and used for land productivity analysis and yield assessment, as well as Landsat 8, Sentinel-2 and Sentinel-1 time series are utilized for crop mapping. We calculate for the whole territory of Ukraine SDG indicators: 15.1.1 – ‘Forest area as proportion of total land area’; 15.3.1 – ‘Proportion of land that is degraded over total land area’; and 2.4.1 – ‘Proportion of agricultural area under productive and sustainable agriculture’. Workflows for calculating these indicators were implemented in a Virtual Laboratory Platform. We conclude that newly available high-resolution remote sensing products can significantly improve our capacity to assess several SDGs indicators through dedicated workflows.  相似文献   
95.
遥感图像人机交互判读方法研究及其应用   总被引:9,自引:0,他引:9  
对于大型复杂的遥感判读任务,往往需要灵活地运用不同的判读方法,才能取得令人满意的效果,然而传统目视判读和常规计算机分类都难以满足这一要求,笔者设计了屏幕目视判读,改进型监督自动分类,分区自动分类,辅助波段分类,动态变化判读,人机混合判读和多组分工判读等遥感图像人机交互判读方法,把计算机自动分类与人工判读的优势相结合,对于提高图像判读精度,速度和高效率的遥感专题信息生成,帮助判读人员更好地完成各种遥感图像的判读任务都具有重要的意义,该文探讨了以上方法的特点,适用范围与实现方法,并给出了一些实例加以说明。  相似文献   
96.
基于标点随机过程的遥感影像道路提取   总被引:1,自引:1,他引:1  
在分析贝叶斯方法用于遥感影像目标提取技术的基础上.基于标点随机过程方法,利用线状地物的整体几何约束和地物之间的空间结构及相关关系对目标构建数学模型.提取线状地物.并以道路网的自动提取为例,详细阐述了此算法。  相似文献   
97.
98.
基于数字地价模型的地价监测点配置研究   总被引:1,自引:0,他引:1  
从数字地价模型的建立、格网数字地价模型向TIN转化、TIN节点与宗地图层叠加拟合完成地价监测点的定位配置、结合市场比较法的监测点地价更新、TIN数字地价模型更新等几个方面详细阐述了数字地价模型运用于地价监测点配置的具体方法。并将这一配置模式与以标准宗地为载体的配置模式进行了比较分析。  相似文献   
99.
硬脆性围岩在开挖完成后,其强度在高应力的影响下具有明显的时间效应,这导致围岩开挖损伤区的发展也呈现出与时间相关的特征。在岩石强度时效性演化模型的基础上,以锦屏二级水电站试验洞钻孔摄像、声波、变形监测等开挖损伤区实测结果为目标函数,采用正交设计方法、最小二乘支持向量机模型、粒子群优化算法等方法,建立了考虑时间效应的LSSVM-PSO智能反演分析方法,并以锦屏二级水电站试验洞为例,研究了开挖完成后的25 d里,围岩强度在高地应力条件下的时效性演化特征,进而获得这一时段内开挖损伤区扩展过程。研究结果表明:(1)高应力地区,隧洞开挖后,围岩损伤区的主要扩展方向受地应力控制,且最大扩展方向为最小主应力方向,且破坏区(破坏接近度FAI≥2)也集中于该方向; (2)开挖损伤区面积随时间近似呈S形曲线变化,表明开挖损伤区初始发展较为缓慢,随着时间推移呈现线性增加的趋势,最后又逐渐趋于稳定;(3)开挖后第3~10 d为开挖损伤区快速增长阶段。该研究成果对高应力地区硬脆性围岩开挖损伤区时效性演化研究具有指导意义。  相似文献   
100.
This paper reviews the linkages among energy and mineral resources and economic, social, and environmental sustainability. Nonrenewable resources are shown to be integral components of sustainability, regardless of which paradigmatic definition of the concept is invoked. Potential measures of the degree to which nonrenewable resources contribute to or detract from sustainability are presented. We conclude that a set of such measures should be incorporated in the comprehensive framework of sustainability currently being developed by the Federal government. National scale indicators could be presented within the structure of the seven criteria from the Santiago Declaration, whereas a life cycle or materials flow approach could be used when sustainability of specific resources is at issue.  相似文献   
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