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921.
Dragos Simandan 《The Professional geographer》2013,65(3):390-395
Wisdom is at once one of the most elusive and most valued kinds of knowledge. Empirical research shows that, indeed, across cultures, people hope that life experience will eventually make them wiser. The problem is that, to date, the academic study of wisdom and of the processes by which it can be learned has been dominated by psychologists. The first part of the article reviews the state-of-the-art psychological scholarship on wisdom to show how that conceptualization lacks geographical sensitivity and therefore misses some of the crucial geographical mechanisms by which people become wiser. The second part of the article singles out and focuses on one such mechanism, namely, the learning of wisdom through geographical dislocations. By drawing on insights from the study of international migration, exile, and transculturation in postcolonial contexts, the final part of the article suggests specific learning processes that might strengthen the hypothesis that geographical dislocations and the attendant cross-cultural experiences they generate are often conducive to wisdom. 相似文献
922.
Karen Ross 《The Professional geographer》2013,65(2):180-186
It is rare to hear about the gendered risks of field work. My experiences with sexual violence with key informants forced me to assume a variety of defensive behaviors, which ran counter to the ways that scholarly discussions of methods tend to emphasize the importance of reducing distance and shifting power away from the researcher in a cross-cultural context. By considering gendered risks, I question the extent to which an idealized male researcher is still viewed as the archetype from which methods are conceptualized and practiced, and the implications are then discussed. 相似文献
923.
Accurately mapping the spatial distribution of soil total nitrogen is important to precision agriculture and environmental management. Geostatistical methods have been frequently used for predictive mapping of soil properties. Recently, a local regression method, geographically weighted regression (GWR), got the attention of environmentalists as an alternative in spatial modeling of environmental attributes, due to its capability of incorporating various auxiliary variables with spatially varied correlation coefficients. The objective of this study is to compare GWR and ordinary cokriging (OCK) in predictive mapping of soil total nitrogen (TN) using multiple environmental variables. 353 soil Samples within the surface horizon of 0–20 cm in a study area were collected, and their TN contents were measured for calibrating and validating the GWR and OCK interpolations. The environmental variables finally chosen as auxiliary data include elevation, land use types, and soil types. Results indicate that, although OCK is slightly better than GWR in global accuracy of soil TN prediction (the adjusted R2 for GWR and OCK are 0.5746 and 0.6858, respectively), the soil TN map interpolated by GWR shows many details reflecting the spatial variations of major auxiliary variables while OCK smoothes out almost all local details. Geographically weighted regression could account for both the spatial trend and local variations, whilst OCK had difficulties to capture local variations. It is concluded that GWR is a more promising spatial interpolation method compared to OCK in predicting soil TN and potentially other soil properties, if a suitable set of auxiliary variables are available and selected. 相似文献
924.
This study attempts to identify areas with a high level of discrepancy in the probability for an individual to exceed the threshold of walking time for grocery shopping. It is based on an assumption that a higher discrepancy is associated with more relative disadvantages for socially excluded people, the elderly, with no car and unemployed. A geographically weighted logistic model that incorporates individual constraints and spatial accessibility is developed to yield a probability, capturing the spatial variation of relations of factors. In the city of Tokyo, the north-eastern area shows a significant discrepancy for the socially excluded group. The distribution of high level of discrepancy differs compared to that of the area with low accessibility. This study's methodology and results provide convincing evidence that in determining food desert areas, relative accessibility estimated with personal attributes should be taken into account. 相似文献
925.
M. Morad A. I. Chalmers P. R. O’Regan 《International journal of geographical information science》2013,27(3):347-353
ABSTRACT There is growing interest in the use of images in GIS applications. This paper examines the role of root-mean-square error in assessing the accuracy of digitisation and image–to–world transformation, The study employed Arc/Info software, using an aerial photograph of a small coastal settlement as the base image. The transformed image was overlayed onto a calibrated digital cadastre of the town to evaluate (visually) the geometric integrity of the image rectification. While not dismissing the relevance of rms error in the statistical appraisal of data quality in GIS, the study failed to confirm a workable association between rms error and the quality of image transformation. No apparent improvement in the quality of image transformation was achieved as a result of reducing rms error directly, by eliminating the control points with high residual error. 相似文献
926.
Liangxu Liu Yongping Zhang JinSong Hu 《International journal of geographical information science》2013,27(10):1789-1810
With a huge volume of trajectories being collected and stored in databases, more and more researchers try to discover outlying trajectories from trajectory databases. In this article, we propose a novel framework called relative distance-based trajectory outliers detection (RTOD). In RTOD, we first employed relative distances to measure the dissimilarity between trajectory segments, and then formally defined the outlying trajectories based on distance measures. In order to improve the time performance, we proposed an optimization method that employs R-tree and local feature correlation matrix to eliminate unrelated trajectory segments. Finally, we conducted extensive experiments to estimate the advantages of the proposed approach. The experimental results show that our proposed approach is more efficient and effective at identifying outlying trajectories than existing algorithms. Particularly, we analyzed the effect of each parameter in theory. 相似文献
927.
采用ISSR标记技术对来自不同产地的6个坛紫菜(Porphyra haitanensis)无性系和两个条斑紫菜(P.yezoensis)无性系进行了遗传差异的分析。结果表明,7条ISSR引物在8个紫菜系中共扩增出59条片段,全部表现出多态性。根据Nei等的相似性系数得出8个紫菜系间的遗传距离在0.274—0.746之间。用UPGMA方法作出的系统树中各紫菜基本上是按照产地进行聚类,从而推测紫菜的遗传差异可能与地域分布相关。本文结果也证明了ISSR与RAPD、AFLP等标记技术一样适用于紫菜的遗传多样性分析。 相似文献
928.
山区错季草莓的气候生态适应性分析 总被引:6,自引:3,他引:3
2003~2004、2004~2006年度在阜平山区进行了引种草莓的田间试验。试验证明阜平山区温度、降水、日照等气候生态条件能够满足露地草莓生长发育的需求,由于阜平山区气温低于同期河北平原(以满城县为例)气温,草莓从开花到成熟各发育期均滞后于河北平原,成熟期滞后近1个月,可以通过错季生产使草莓生产旺季与平原地区错开,从而赢得较高的价格;所生产的错季草莓品质优良,果实中可溶性固形物含量和维生素C含量较河北平原对应品种分别高50%和18%;生产效益明显高于当地原来的种植方式,年毛收入是原来种植方式的6.3倍。运用农业气候相似分析方法,论证了阜平山区从河北平原引种草莓是可行性的。 相似文献
929.
电气系统中电涌保护器的雷电流能量配合设计 总被引:4,自引:3,他引:1
分析了电涌保护器(SPD)使用中所涉及到的雷电流能量配合设计。首先分析了单级SPD与被保护设备之间的配合,使用最大振荡距离和耦合距离的计算公式来测算配合的成功性;其次分析了多级SPD之间的配合,着重分析了两级SPD(开关型和限压型组合)的配合,并采用瞬态级间电压降微分方程作为能量配合中所必须遵循的关系式,以及用不同雷电流波形来计算解耦合器的大小,最后提出一个可行的SPD能量配合设计基本步骤。 相似文献
930.
Discretizing a domain of interest into a set of particles for discrete element simulation is the first step to generate a specimen. An improved algorithm, the Seed Expansion Method (SEM), is proposed in this work. A seed is first generated inside a given domain. Then, the domain is filled by the seed expansion based on a local Delaunay tessellation and a distance function. An optional operation, refilling, is suggested to further improve the packing density after the completion of SEM. Polydisperse dense packing can be generated by the proposed method for an arbitrarily shaped domain in both 2D and 3D. A specimen can be obtained that approximately conforms to a specified size distribution and packing density. Multiple subdomains of a domain can be filled by packings with different densities and size distributions. A specimen with higher density can be obtained by comparing it with the existing methods. Mathematically, the features of the method include both simplicity and high efficiency. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献