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   1198篇
  免费   81篇
  2024年   7篇
  2023年   22篇
  2022年   11篇
  2021年   6篇
  2020年   60篇
  2019年   31篇
  2018年   98篇
  2017年   98篇
  2016年   84篇
  2015年   54篇
  2014年   52篇
  2013年   291篇
  2012年   43篇
  2011年   45篇
  2010年   31篇
  2009年   33篇
  2008年   30篇
  2007年   13篇
  2006年   22篇
  2005年   20篇
  2004年   9篇
  2003年   12篇
  2002年   17篇
  2001年   16篇
  2000年   12篇
  1999年   10篇
  1998年   12篇
  1997年   8篇
  1996年   10篇
  1995年   8篇
  1994年   11篇
  1993年   15篇
  1992年   7篇
  1991年   10篇
  1990年   10篇
  1989年   8篇
  1988年   7篇
  1987年   7篇
  1986年   10篇
  1985年   2篇
  1982年   6篇
  1981年   5篇
  1977年   2篇
  1972年   1篇
  1970年   1篇
  1969年   2篇
  1962年   1篇
  1959年   2篇
  1956年   1篇
  1950年   3篇
排序方式: 共有1279条查询结果,搜索用时 31 毫秒
51.
India's oilseeds sector, which includes its coconut economy, experienced drastic changes in the wake of agricultural liberalization in the mid‐1990s. A persistent coconut crisis ‘narrative’ emerged after sharp price declines between 2000 and 2002 in which small farmers in the state of Kerala, India's main coconut producer, were identified as victims of the liberalized importation of cheap palm oil. This article describes this crisis narrative based on a literature review of academic and official reports, and challenges its problem analysis by juxtaposing it with information from ethnographic research with local farmers and traders. The research indicates that local labour shortages and increased regional competition also had a strong impact on Kerala's coconut market, production and processing, which varied from region to region. Furthermore, small farmers, with their diversified livelihoods, did not recognize a ‘crisis’ as such. Drawing upon the ‘advocacy coalition framework’, the article also indicates reasons for the emergence and persistence of the coconut crisis narrative and points to complex processes of restructuring social space in the age of globalization.  相似文献   
52.
In the Iberian Peninsula, the copper metallurgy from the Chalcolithic to the Middle Bronze Age (MBA) was mostly characterized by low arsenic contents. A collection of 53 MBA artefacts from southern Portugal was analysed by micro‐EDXRF, optical microscopy, SEM–EDS and Vickers to investigate the metal composition and manufacture. No technological distinction was found between artefacts from domestic and funerary contexts, which were radiocarbon‐dated to 2000–1500 cal bc . The arsenic contents of almost 100 MBA artefacts from this region, including the above‐mentioned set, have a Gaussian distribution with a high average (3.9 wt% As). Possible explanations are discussed for this distinctive metallurgy at the south‐western end of the Iberian Peninsula.  相似文献   
53.
54.
In 1665, Robert Hooke published his major work in microscopy, Micrographia, a defense of experimental philosophy. The following year, Margaret Cavendish, Duchess of Newcastle, published at her own expense a treatise and a novel that undermined the basis of this new science. The dispute broke out at the initiative of the Duchess, in the context of a vast controversy about the legitimacy and the efficiency of optical instruments in natural philosophy. All the figures of the dual are used, except one: the counterattack. Cavendish, indeed, was alone on the battlefield. Is it possible to call a dual a battle with only one combatant? This particular case of dispute that stops owing to the shortage of combatants is the subject of this article.  相似文献   
55.
After a brief review of some of the general problems posed by Sophron’s work, the paper analyses Sophron’s fr. 3 K.-A., offering a detailed commentary and a new interpretation of the passage.  相似文献   
56.
Abstract

Ever since Jimmy Rabbitte proffered his oft-quoted “niggers of Europe” line in Roddy Doyle’s The Commitments (1987), contemporary Irish culture, especially during the boom years, was characterised by an insistent revisiting of popular music as a metaphor for interracial and/or intercultural connection or understanding. Cross-cultural identification through music may be seen, in Werner Sollors’s memorable terms, as an eschewing of “descent” relations in favour of “consensual” relations. This essay revisits the music metaphor as it has manifested itself in Irish fiction since it was announced officially that Ireland had entered recession in 2008. Specifically, it explores Kevin Curran’s Beatsploitation (2012) and Joseph O’Connor’s The Thrill of It All (2014) arguing that, through their deployment of the music metaphor, the novels stage the murky politics of contemporary Irish iterations of consent and descent. By exposing the extent to which the rhetoric of Irish economic recovery is yoked to paradoxical invocations of volitional and ancestral Irishness, the novels urge their readers to consider the ways in which discourses of economic recovery work to reinforce and perpetuate patterns of exclusion and marginalisation established during the Celtic Tiger years.  相似文献   
57.
Wright, A.J., Plusquellec, Y. &; Gourvennec, R., February 2016. Devonian operculate corals (Calceolidae, Cnidaria) from the Massif Armoricain, France. Alcheringa 40, xxx–xxx. ISSN 0311-5518

The operculate coral Calceola gervillei Bayle, 1878 Bayle, E., 1878. Fossiles principaux des terrains de la France. Explication de la Carte Géologique de France 4(1), 1158. [Google Scholar] is described for the first time on the basis of the type material from the Cotentin region of Normandy (North Armorican Domain), from Early Devonian (likely upper Lochkovian to lower Pragian) strata, and is chosen as the type species of the monotypic new genus Gerviphyllum. The new genus is also present in the l’Armorique Formation (lower Pragian) of the Plougastel Peninsula (Central Armorican Domain) as Gerviphyllum sp. cf. G. gervillei. One locality in the upper Emsian (Polygnathus serotinus Conodont Zone) Le Fret Formation, on the northern coast of the Crozon Peninsula, has yielded operculate coral specimens described here as ?Chakeola sp., the first (tentative) record of the genus outside eastern Australia, south China and Vietnam. The operculate coral Calceola collini sp. nov. is described from six localities in the early Middle Devonian (Eifelian: Polygnathus costatus Conodont Zone) Saint-Fiacre Formation of the Plougastel and Crozon Peninsulas (Central Armorican Domain), despite the fact that knowledge of the internal characters, especially of the operculum, of the type species Calceola sandalina is very limited. From an extensive review of published references to Calceola from France, we conclude that only the record of Collin (1929 Collin, L., 1929. Un nouveau gisement à calcéoles dans le Dévonien de la Presqu’île de Crozon (Finistère). Bulletin de la Société Géologique et Minéralogique de Bretagne 7(3/4), 201208. [Google Scholar]) is valid.

Anthony Wright (), GeoQuEST Research Centre, School of Earth &; Environmental Sciences, University of Wollongong, Wollongong, NSW, 2522, Australia; Yves Plusquellec () and Rémy Gourvennec (), Université de Bretagne Occidentale, CNRS-UMR 6538 ‘Domaines océaniques’, Laboratoire de Paléontologie, UFR Sciences et Techniques, 6 avenue Le Gorgeu, CS 98837, F-29283, Brest, France. Received 1.10.2015; revised 8.12.2015; accepted 14.12.2015.  相似文献   
58.
Intersectionality is a complex concept to deal with when doing research but also when teaching the interrelationships between space and social relations. Here we present “Relief Maps” as a visual tool for teaching intersectionality and its spatial dimension in higher education courses. “Relief Maps” are a model developed for research and applied in a Geography and Gender course at the Universitat Autònoma de Barcelona (UAB) with the aim of promoting student reflection on the relationships between power structures, places and lived experiences, starting from their everyday lives.  相似文献   
59.
Teaching of critical spatial thinking in higher education empowers graduates to effectively engage with spatial data. Geographic information systems (GIS) and science are taught to undergraduates across many disciplines; we evaluate how this contributes to critical spatial thinking. The discipline of GIS covers the whole process of spatial decision-making, but GIS modules often ignore the context setting of spatial problems, and just cover the technical aspects of how to use GIS software. We outline how some existing GIS practicals could be improved to focus on the development of critical spatial thinking skills, competences and abilities that are valuable to graduates.  相似文献   
60.
Research projects undertaken in the Cantabrian region since 1980 have produced new, high-quality information about the neolithisation process(es) in this area. It is now necessary to review this archaeological information and test the main hypotheses put forward to explain it. This paper presents an update on the archaeological evidence (sites, chronological dates, archaeozoological, archaeobotanical and technological information) for the early Neolithic in the Cantabrian region. It summarizes recent research on neolithisation in the region, and assesses the impact of this process during the early Neolithic, and its later consolidation. Although the available information is still incomplete, it is now possible to identify the focal point of the introduction of elements characteristic of the Neolithic way of life in the region. Current evidence suggests that it is in the eastern sector, where the earliest arrival of domesticates and new technologies such as pottery has been attested. The existence of continuities—such as sustained reliance on hunting and gathering and the coexistence of old and new funerary rites—suggests the persistence of native populations, which gradually participated in the neolithisation process after an ‘availability phase’.  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