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911.
This paper introduces a novel technique for object detection using genetic algorithms and morphological processing. The method employs a kind of object oriented structure element, which is derived by genetic algorithms. The population of morphological filtersis iteratively evaluated according to a statistical performance index corresponding to object extraction ability, and evolves into an optimal structuring element using the evolution principles of genetic search. Experimental results of road extraction from high resolution satellite images are presented to illustrate the merit and feasibility of the proposed method. 相似文献
912.
基于多核学习的高分辨率遥感图像目标检测方法 总被引:1,自引:0,他引:1
为更有效地实现复杂场景中的多类目标同时检测,本文提出了一种基于多核学习算法进行目标检测的框架。该方法由特征提取和模型训练2个阶段组成。特征提取阶段,引入了多尺度下的点特征、表观特征同时对多类目标进行综合描述;模型训练阶段,分别采用加权相加和相乘2种方法将提取的各个基础特征组合起来,在支持向量机的框架下对各特征所代表的基础核权重进行学习。将训练所得的分类器结合滑动窗搜索技术对遥感图像进行目标检测实验,结果表明,与传统单核支持向量机相比,准确率更高。 相似文献
913.
To retrieve the object region efficaciously from massive remote sensing image database, a model for content-based retrieval of remote sensing image is given according to the characters of remote sensing image application firstly, and then the algorithm adopted for feature extraction and multidimensional indexing, and relevance feedback by this model are analyzed in detail. Finally, the contents intending to be researched about this model are proposed. 相似文献
914.
To have sustainable management and proper decision-making, timely acquisition and analysis of surface features are necessary. Traditional pixel-based analysis is the popular way to extract different categories, but it is not comparable by the achievements that can be achieved through the object-based method that uses the additional characteristics of features in the process of classification. In this paper, three types of classification were used to classify SPOT 5 satellite image in mapping land cover; Support vector machine (SVM) pixel-based, SVM object-based and Decision Tree (DT) pixel-based classification. Normalised Difference Vegetation Index and the brightness value of two infrared bands (NIR and SWIR) were used in manually developed DT classification. The classification of the SVM (pixel based) was generated using the selected groups of pixels that represent the selected features. In addition, the SVM (object based) was implemented by using radial-based function kernel. The classified features were oil palm, rubber, urban area, soil, water and other vegetation. The study found that the overall classification of the DT was the lowest at 69.87% while those of SVM (pixel based) and SVM (object based) were 76.67 and 81.25%, respectively. 相似文献
915.
Recent technical advances in remote sensing data capture and spatial resolution lead to a widening gap between increasing data availability on the one hand and insufficient methodology for semi-automated image data processing and interpretation on the other hand. At the interface of GIS and remote sensing, object-based image analysis methodologies are one possible approach to close this gap. With this, methods from either side are integrated to use both the capabilities of information extraction from image data and the power to perform spatial analysis on derived polygon data. However, dealing with image objects from various sources and in different scales implies combining data with inconsistent boundaries. A landscape interpretation support tool (LIST) is introduced which seeks to investigate and quantify spatial relationships among image objects stemming from different sources by using the concept of spatial coincidence. Moreover, considering different categories of object fate, LIST enables a change categorization for each polygon of a time series of classifications. The application of LIST is illustrated by two case-studies, using Landsat TM and ETM as well as CIR aerial photographs: the first showing how the tool is used to perform object quantification and change analysis; the latter demonstrating how superior aggregation capabilities of the human brain can be combined with the fine spatial segmentation and classification. Possible fields of application are identified and limitations of the approach are discussed. 相似文献
916.
917.
《The Professional geographer》2013,65(3):263-264
Promotion of nonacademic geography is a logical response to curtailment of opportunity for new teaching careers. Yet this necessary redirection of effort must be accompanied by renewed dedication to education and especially to nonprofessional undergraduate education. The case for geography in the liberal arts curriculum may well be a strong one, but questions about what we can offer need to be raised more frequently among ourselves if we are to respond effectively when such questions are asked by outsiders. 相似文献
918.
《自然地理学》2013,34(4):319-336
Visual interpretation of aerial photography suggests that certain geomorphological similarities exist between the hummocky terrain of central Alberta, Canada, and the Rogen terrain of Nunavut, Canada. This study statistically compares the two landform types based on measures of depression shapes and ridge orientations. Comparison of depression shapes indicates that two of three sample areas chosen from the hummocky terrain study area are statistically similar to those of the Rogen terrain study area. Analysis of ridge orientations indicates the ridge crests from two of three hummocky terrain sample areas, and ridge crests from within the Rogen terrain study site all exhibit a preferred trend. Variability in the process of formation may explain why only particular areas throughout the hummocky terrain exhibit patterns similar to the Rogen terrain and others do not. Statistical similarities in two-dimensional form between the hummocky terrain of central Alberta and the Rogen terrain of the Northwest Territories however, suggest that these landforms may have a common or similar origin. 相似文献
919.
Louis Arbez Aurelien Royer Danielle Schreve Remi Laffont Serge David Sophie Montuire 《第四纪科学杂志》2021,36(2):224-238
Lemmus and Myopus are two lemming species with distinct habitat requirements but which show very similar dental morphologies. They are thus extremely difficult to distinguish from one another in the fossil record on the basis of their dental remains, leading to poor understanding of the palaeobiogeographical evolution of Myopus as well as inaccurate palaeoenvrionmental reconstructions. Currently, the presence of Myopus in the fossil register from the Pleistocene is still debated and no firm occurrence of this lemming in western Europe has yet been confirmed for the Late Pleistocene. In this paper, we used geometric morphometrics on modern material to establish morphological differences between Lemmus and Myopus teeth (first lower and third upper molars). Morphological data were then used to build a robust linear discriminant model able to confidently classify isolated teeth of these two genera, and finally, linear discriminant models were used on fossil remains of Lemmus/Myopus from two Late Pleistocene archaeological/palaeontological sites (Grotte des Gorges and Gully Cave). This study demonstrates, for the first time, the presence of Myopus schisticolor in west European Late Pleistocene sites between the end of Marine Isotope Stage 3 and the beginning of the Holocene, during climatic events that favoured the development of taiga forest of birch and pine in these regions. 相似文献
920.
利用Doppler雷达产品,结合常规观测资料对2008年7月25日中国准噶尔盆地南缘冰雹、强降水的雷达回波结构演变特征进行分析。结果表明:此次冰雹、强降水天气过程发生在西伯利亚至巴尔喀什湖冷槽东南象限的对流不稳定层结中,近低层至地面有中尺度辐合切变线。强风暴的演变可归为"逗点—‘人’字形—螺旋形"3个回波阶段,相应径向速度图上出现"逆风区"、中气旋和辐合区。冰雹的雷达回波强度中心值超过65 dBz6,0 dBz回波顶高为5.5 km,65 dBz回波顶高为3.0 km。垂直累积液态含水量由10 kg·m^-2增至70 kg·m^-2。强降水的雷达回波强度中心值达60 dBz,55 dBz回波顶高为3.7 km6,0 dBz回波顶高为2.2 km。垂直累积液态含水量由15 kg·m^-2增加至55kg·m^-2。Doppler雷达产品对冰雹、强降水天气监测预警具有指示意义。 相似文献