首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   163篇
  免费   15篇
  2024年   1篇
  2023年   7篇
  2022年   2篇
  2021年   1篇
  2020年   6篇
  2019年   7篇
  2018年   25篇
  2017年   19篇
  2016年   15篇
  2015年   7篇
  2014年   5篇
  2013年   26篇
  2012年   2篇
  2011年   6篇
  2010年   9篇
  2009年   4篇
  2008年   4篇
  2007年   2篇
  2006年   3篇
  2005年   1篇
  2004年   1篇
  2003年   1篇
  2002年   2篇
  2001年   1篇
  2000年   2篇
  1999年   2篇
  1998年   2篇
  1997年   1篇
  1996年   1篇
  1995年   1篇
  1993年   1篇
  1992年   2篇
  1990年   1篇
  1987年   1篇
  1986年   3篇
  1985年   3篇
  1975年   1篇
排序方式: 共有178条查询结果,搜索用时 15 毫秒
31.
32.
Dr. Haakon Sæthre was a leader of Norwegian neurology and psychiatry. He was resourceful, compassionate and had immense pride in his independent homeland. He described Sæthre-Chotzen syndrome (acrocephalosyndactyly type III). When Nazi Germany occupied Norway during World War II, Sæthre fearlessly and actively resisted, from revoking his medical association membership, to hiding persecuted Jews as patients in his psychiatric ward and aiding in their escape to Sweden, to managing the largest “illegal” food warehouse in Oslo with Danish humanitarian aid. As a prominent and noticeable citizen, he was arrested and executed by the Nazis in reprisal for the resistance's assassination of a hated Norwegian Nazi. His legacy lives on in Norway, where he was honored by a scholarship fund, a portrait and multiple plaques at Ullevål Hospital, and a street and memorial statue in his hometown. He was a hero and should be remembered by all who practice neurology.  相似文献   
33.
Summary: Mummified human remains have been preserved in the cool, well-ventilated crypts of old Finnish churches, which were popular burial sites among the elite of the early modern period. Here, the authors present the results of a computed tomography study of the remains of an early 17th-century vicar of Keminmaa. They examined the preservation of his remains and made several pathological findings; the causes of the latter possibly had a severe impact on his health. He was a large man who achieved relative longevity for his time, although he suffered from conditions related to obesity. There were also potential indications of tuberculosis. Inflammatory changes, for example, had afflicted his spine.  相似文献   
34.
35.
Marsola, J.C.A., Grellet-Tinner, G., Montefeltro, F.C., Sayão, J.M., Hsiou, A.S. & Langer, M.C., 2014. The first fossil avian egg from Brazil. Alcheringa 38, 563–567. ISSN 0311-5518.

In contrast to the rich record of eggs from non-avian dinosaurs, complete eggs attributable to Mesozoic birds are relatively scarce. Nevertheless, several well-preserved specimens have been discovered over the last three decades revealing functional and phylogenetic characters that shed light on the breeding strategies of extinct birds. Here we report the first fossil avian egg from Brazil, which was discovered in Upper Cretaceous strata of São Paulo in the southeastern part of the country. The taxonomic identity and structural features of the biomineralized tissues were determined using a combination of Scanning Electron Microscopy, Wave Dispersion Energy analyses and Computed Tomography. These show that the 125.5-μm-thick shell of the 31.4?×?19.5?mm egg incorporates three structural layers of similar thickness with both prismatic and aprismatic boundaries. Close similarity between the Brazilian bird egg and those of enantiornithines from the Upper Cretaceous Bajo de la Carpa Formation (Río Colorado Subgroup) of Argentina advocates affinity with basal Ornithothoraces. Furthermore, coherency of their depositional contexts might imply a compatible preference for breeding and nesting environments.

Júlio Cesar de A. Marsola [], Annie Schmaltz Hsiou [] and Max C. Langer [], Laboratório de Paleontologia de Ribeirão Preto, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Avenida Bandeirantes 3900, Ribeirão Preto, São Paulo state, 14040-901, Brazil. Gerald Grellet-Tinner [], Centro Regional de Investigaciones La Rioja—Consejo Nacional de Investigaciones Científicas y Técnicas, Entre Ríos y Mendoza s/n, 5301 Anillaco, Argentina; Orcas Island Museum, PO Box 134, 181 North Beach Road, Eastsound, WA 98245. Felipe C. Montefeltro [], Departamento de Zoologia, Universidade Estadual Paulista, Avenida 24A 1515, Rio Claro, São Paulo State, 13506-900, Brazil. Juliana M. Sayão [], Laboratório de Diversidade do Nordeste, Núcleo de Biologia, Centro Acadêmico de Vitória, Universidade Federal de Pernambuco, Rua do Alto do Reservatório s/n, Bela Vista, Vitória de Santo Antão, Pernambuco state, 52050-480, Brazil. Received 18.12.2013; revised 30.4.2014; accepted 18.5.2014.  相似文献   
36.
The article discusses the significance of the concept of gender for historical analysis, particularly on the basis of the importance of different types of ego-documents for the self-expression of the sexes. Attention is focused mainly on the status of autobiographies as a historical source, with some consideration of other types of life writing. It is shown how the form of this genre affects the sexes’ access to self-expression and how their differing ‘cultural space’ opens up opportunities for people's self-creation. The development is viewed in an international light, with reference to both ego-documents and history in general, and it is shown how sources of this kind and women's perspectives are necessary preconditions for the humanities to be able to achieve an important reinterpretation of older historical arguments. Each can provide scholars with opportunities to investigate material that has previously defied their analysis.  相似文献   
37.
In this paper, based on the case study of the aerospace cluster of the Basque Country (Spain), we aimed at analysing how local industries develop a new specialization, that is, how a cluster emerges, and how it evolves over time. For that purpose, apart from considering local factors (both forces that are internal to the cluster and to the territory), we explicitly consider the role of institutional and technological changes, and how they affect industry structure and governance patterns of global value chains (GVCs). We observe that global-scale regulations (deregulation and competition policy) and technological change, together with local factors such as the existence of anchor firms, local policies, related variety and social capital at regional and cluster levels played a significant role in the emergence of the cluster and how it became inserted in the GVCs. Later on, the development of suppliers' capabilities also had a relevant role in the evolution of the governance patterns of GVCs.  相似文献   
38.
The Real Pragmática of 1765 of Free Grain Trade was one of the most influential events in eighteenth century Spanish political and economic history? But was it influential in the Americas? Despite the abundant scholarship on the Bourbon reforms, we do not know much about the application of the Pragmática or more broadly about policies that affected domestic grain trade in the Americas. In this article I argue that the Pragmática was influential in increasing the participation of the viceroy in matters of wholesale and regional grain trade. Such changes in policies as applied in New Spain involved both pragmatism and a centralization of power, rather than a dogmatic support for free trade policies or a staunch support of traditional doctrines. In this I believe that New Spain did not differ from contemporary Western European countries, in which free trade was constantly being negotiated between different actors and authorities of various levels.  相似文献   
39.
40.
Practically all archeological assemblages are palimpsests. In spite of the high temporal resolution of Abric Romaní site, level O, dated to around 55 ka, is not an exception. This paper focuses on a zooarcheological and taphonomic analysis of this level, paying special attention to spatial and temporal approaches. The main goal is to unravel the palimpsest at the finest possible level by using different methods and techniques, such as archeostratigraphy, anatomical and taxonomical identification, taphonomic analysis, faunal refits and tooth wear analysis. The results obtained are compared to ethnoarcheological data so as to interpret site structure. In addition, activities carried out over different time spans (from individual episodes to long-term behaviors) are detected, and their spatial extent is explored, allowing to do inferences on settlement dynamics. This leads us to discuss the temporal and spatial scales over which Neanderthals carried out different activities within the site, and how they can be studied through the archeological record.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号