全文获取类型
收费全文 | 2256篇 |
免费 | 98篇 |
出版年
2023年 | 13篇 |
2020年 | 27篇 |
2019年 | 61篇 |
2018年 | 70篇 |
2017年 | 104篇 |
2016年 | 90篇 |
2015年 | 64篇 |
2014年 | 56篇 |
2013年 | 756篇 |
2012年 | 54篇 |
2011年 | 65篇 |
2010年 | 55篇 |
2009年 | 58篇 |
2008年 | 47篇 |
2007年 | 36篇 |
2006年 | 29篇 |
2005年 | 22篇 |
2004年 | 39篇 |
2003年 | 33篇 |
2002年 | 33篇 |
2001年 | 26篇 |
2000年 | 25篇 |
1999年 | 26篇 |
1998年 | 17篇 |
1997年 | 17篇 |
1996年 | 15篇 |
1995年 | 17篇 |
1993年 | 30篇 |
1992年 | 14篇 |
1991年 | 20篇 |
1990年 | 17篇 |
1989年 | 15篇 |
1988年 | 15篇 |
1987年 | 15篇 |
1986年 | 17篇 |
1985年 | 16篇 |
1984年 | 19篇 |
1983年 | 12篇 |
1982年 | 13篇 |
1981年 | 17篇 |
1980年 | 25篇 |
1979年 | 14篇 |
1978年 | 17篇 |
1977年 | 31篇 |
1976年 | 33篇 |
1975年 | 16篇 |
1973年 | 13篇 |
1972年 | 13篇 |
1971年 | 13篇 |
1969年 | 10篇 |
排序方式: 共有2354条查询结果,搜索用时 15 毫秒
971.
Holly M. Widen James B. Elsner Stephanie Pau Christopher K. Uejio 《Geographical analysis》2016,48(2):115-131
Graphical inference, a process refined by Buja et al., can be a useful tool for geographers as it provides a visual and spatial method to test null hypotheses. The core idea is to generate sample datasets from a null hypothesis to visually compare with the actual dataset. The comparison is performed from a line‐up of graphs where a single graph of the actual data is hidden among multiple graphs of sample data. If the real data is discernible, the null hypothesis can be rejected. Here, we illustrate the utility of graphical inference using examples from climatology, biogeography, and health geography. The examples include inferences about location of the mean, change across space and time, and clustering. We show that graphical inference is a useful technique to answer a broad range of common questions in geographical datasets. This approach is needed to avoid the common pitfalls of “straw man” hypotheses and “p‐hacking” as datasets become increasingly larger and more complex. 相似文献
972.
973.
974.
James Cotton 《History of European Ideas》2016,42(8):1089-1104
Charles Howard (‘Dick’) Ellis, born in Sydney in 1895 and a Great War veteran, was working as a journalist in Vienna and Geneva when he wrote one of the most comprehensive books of the time on the League: The Origin, Structure and Working of the League of Nations (1928). Dedicated to the progressive literary figures of the era and showing a particular debt to the writings of the British Labour left, Ellis argued that the internationalism of the age marked a necessary rejection of the anarchic conditions that brought forth the Great War. The League and its associated institutions constituted ‘the first step toward a world society’ that would facilitate the suppression and ultimate removal of the causes of conflict. A remarkable work in itself, this progressive volume was written by a member of British intelligence who had already made a reputation in this sphere and was to go on to hold very senior positions in the 1940s. The question is considered whether the ideas expressed were a product of Ellis's genuine beliefs, or whether they were a mask for his substantive professional role. The circumstances around the writing of this book are also reviewed in an attempt to answer this question, especially given the hitherto accepted scholarly view that Konni Zilliacus of the League Secretariat was the actual author. 相似文献
975.
Lorenzo Lorusso Thierry Lefebvre Béatrice de Pastre 《Journal of the history of the neurosciences》2016,25(1):72-83
The microbiologist Jean Comandon is famous for his studies on the movement of the syphilis bacteria as differentiated in various forms by ultramicroscope. He was also a pioneer on the technical application of the microcinematography in laboratory research. His collaboration with clinicians and surgeons in the study of various pathological disorders is little known. From 1918 to the 1920s, he collaborated with such neurologists as André Thomas, Jean Athanase Sicard, and others in the study of various neurological disorders by using cinematography as a scientific tool for understanding the clinical and pathological mechanisms of diseases. These collaborations allowed him to be involved in the beginnings of the French cinematography industry, especially with Charles Pathé who established a small film studio laboratory in Vincennes where a multidisciplinary group improved the application of cinematography in clinical medical practice. 相似文献
976.
977.
Ricardo Carvalho de Andrade Lima Raul da Mota Silveira Neto 《Journal of regional science》2018,58(1):159-180
In the 1990s, there was a growing process of administrative decentralization that culminated in the creation of 1,016 new municipalities in Brazil. The aim of this paper is to verify the impact of the municipal secessions on the public expenditures and its association with economies of scale. Based on a Differences‐in‐Differences methodology, the obtained set of evidence indicates that those municipalities that underwent a secession process increased their per capita capital expenditures by 14.7 percent. In addition, we show evidence that strongly suggests that this increase in expenses can be explained by a reduction in economies of scale and rent‐seeking behavior. 相似文献
978.
Lucinda R. Backwell Francesco d'Errico William E. Banks Paloma de la Peña Christine Sievers Dominic Stratford 《Journal of Field Archaeology》2018,43(6):417-436
New excavations at Border Cave use high-resolution techniques, including FT-IR, for sediment samples and thin sections of micromorphology blocks from stratigraphy. These show that sediments have different moisture regimes, both spatially and chronologically. The site preserves desiccated grass bedding in multiple layers and they, along with seeds, rhizomes, and charcoal, provide a profile of palaeo-vegetation through time. A bushveld vegetation community is implied before 100,000 years ago. The density of lithics varies considerably through time, with high frequencies occurring before 100,000 years ago where a putative MSA 1/Pietersburg Industry was recovered. The highest percentage frequencies of blades and blade fragments were found here. In Members 1 BS and 1 WA, called Early Later Stone Age by Beaumont, we recovered large flakes from multifacial cores. Local rhyolite was the most common rock used for making stone tools, but siliceous minerals were popular in the upper members. 相似文献
979.
980.
Luis Barba Jorge Blancas Alessandra Pecci Domenico Miriello Murat Cura Gino Crisci Marco Cappa Daniela de Angelis Hasan Bora Yavuz 《Archaeological and Anthropological Sciences》2018,10(2):259-268
Within an interdisciplinary project to study Istanbul’s Hagia Sofia, a georadar survey was carried out in the central nave to assess if the deformations of the structure previously observed could be related to a differential behavior of the subsoil caused by architectural remains underneath. This study faces an unusual challenge since it was necessary to study the space beneath the scaffolding placed for the restoration works. The survey of the central nave was successful and allowed the detection of remains of walls that probably formed the basement of a previous 18- by 22-m structure. In addition, another interesting feature was discovered 2 m below the marble mosaic in the southeastern part of the nave. Although it is not possible to define its function, it seems that there could be a close relationship between this 2- by 3-m buried structure and the marble mosaic in the floor surface. Although some structures were identified under the floor of Hagia Sofia, there are no major changes in the topography of the central nave floor. 相似文献