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   544篇
  免费   21篇
  2023年   7篇
  2021年   4篇
  2020年   12篇
  2019年   19篇
  2018年   13篇
  2017年   20篇
  2016年   24篇
  2015年   11篇
  2014年   11篇
  2013年   138篇
  2012年   23篇
  2011年   17篇
  2010年   16篇
  2009年   21篇
  2008年   9篇
  2007年   11篇
  2006年   8篇
  2005年   7篇
  2004年   12篇
  2003年   5篇
  2002年   8篇
  2001年   7篇
  2000年   4篇
  1999年   13篇
  1998年   5篇
  1997年   6篇
  1996年   5篇
  1995年   11篇
  1994年   6篇
  1993年   4篇
  1991年   5篇
  1988年   2篇
  1987年   3篇
  1986年   2篇
  1985年   3篇
  1984年   7篇
  1983年   12篇
  1982年   6篇
  1981年   2篇
  1980年   5篇
  1979年   9篇
  1978年   10篇
  1977年   4篇
  1976年   7篇
  1975年   7篇
  1973年   3篇
  1972年   4篇
  1971年   2篇
  1970年   2篇
  1965年   2篇
排序方式: 共有565条查询结果,搜索用时 15 毫秒
101.
Abstract

In three books published in 1940, 1956, and 1961, Arthur J. Marder established what became the orthodox view of the development of the British navy in the years leading up to the First World War.1 A.J. Marder, The Anatomy of British Sea Power: A History of British Naval Policy in the Pre-Dreadnought Era, 1880–1965 (New York, 1940); idem,[Fear God and DreadNought: The] C[orrespondence of Admiral of the Fleet Lord] F[isher of Kilverstone: II: Years of Power, 1904–14] (London, 1956); idem, From the Dreadnought to Scapa Flow: I: The Road to War, 1904–14 (Oxford, 1961). Building upon the work of Sir Llewellyn Woodward, who argues that, from the outset of the twentieth century, British naval policy was framed as a response to the threat posed by the rising German naval power,2 E. L. Woodward, Great Britain and the German Navy (London, 1934). Marder makes precise claims about the nature of the response. In particular, he states that, under the leadership of the first sea lord from 1904 to 1910, Admiral Sir John Fisher, the admiralty undertook two root-and-branch reforms. First, it redeployed Britain's fleets and squadrons, reducing the number of foreign stations, scrapping obsolescent vessels, and stationing the most powerful units of the fleet in European waters. Next, at Fisher's prompting, it triggered a naval revolution by ordering the building of a new type of warship, HMS Dreadnought, the world's first turbine-powered, all-big-gun battleship. In both cases, Marder is unambiguous about the motive: the redeployment adjusted Britain's force posture to ensure a preponderance of strength in the vicinity of the North Sea, the theatre in which the expected war with Germany would be fought. The new type of ship was necessary to help to modernize the navy's matériel in keeping with advances in gunnery, propulsion, and torpedoes. If not explicitly aimed at Germany, the new ship would ensure that the navy was better prepared for a war that Fisher perceived to be ‘inevitable’s.  相似文献   
102.
Stable isotope analysis of charred archaeobotanical cereal grains has the potential to provide direct evidence of crop growing conditions in the past and to refine palaeodietary predictions. If isotope values of archaeobotanical material are to be considered robust, it is necessary to characterise the compositional changes associated with their charring and burial. This study used a suite of analytical techniques, including FT-IR and solid state 13C NMR, to characterise changes in the biochemical composition of modern einkorn grains with heating at 230 °C for 2 h, 4 h, 8 h and 24 h, encompassing conditions that replicate their undistorted ancient counterparts. The biochemical composition of archaeobotanical charred einkorn grains was also investigated by FT-IR and solid state 13C NMR in order to assess the changes in composition which occur during burial. Results of FT-IR and solid-state 13C NMR show that heating of modern einkorn grains resulted in Maillard reactions between cereal proteins and starch, forming high molecular weight melanoidins, which contain both alkyl and aromatic carbon. Loss of low molecular weight carbon and nitrogen-containing volatiles resulted in a slight but non-systematic increase in the δ13C values and a systematic increase of 0.8‰ in the δ15N values of the charred einkorn grains. Solid-state 13C NMR shows that the ancient charred einkorn grains consisted entirely of aromatic carbon and retained a similar proportion of nitrogen to their modern 24 h charred counterparts, despite a significantly lower concentration of amino acids. This indicates that the amino acid nitrogen in the ancient charred grains was retained in the stable melanoidins whose polymeric structure makes them resistant to subsequent degradation.  相似文献   
103.
104.
105.
This article provides an indictment of the study of South-East Asian international relations by confronting head-on the problems that have arisen within this field, in particular the way in which Western academics ended up colluding with deeply illiberal regimes in the area, which excluded dissenting opinions, often by deliberately denouncing these opinions as 'polemical'. This study uses the discipline of Sovietology to explore the reasons why South-East Asian studies developed into a closed community of scholarship, often hostile to dissenting viewpoints. The disciplines bear comparison because they both manifestly failed to predict the cataclysms that befell their respective areas of study. The analysis identifies similarities in the way in which the two disciplines seemed to ignore sceptical voices and evolved a shared belief in 'system stability'. As a result, both Soviet studies and the study of South-East Asian international relations developed serious methodological flaws. However, this study argues that South-East Asian studies suffered even more severe disciplinary shortcomings than its Sovietological counterpart because the academic space was further de-intellectualized by the pervasive influence of the authoritarian South-East Asian developmental state which blurred the distinction between scholarship and bureaucracy and which succeeded in co-opting Western academics. The result was to create a field of study that promulgated the tyranny of the single truth, which erroneously perceived South-East Asia as a region of domestic tranquillity and regional order. What, in fact, emerged was an intellectual culture of self-censorship that kept South-East Asian studies within tacit, self-regulated boundaries.  相似文献   
106.
107.
108.
ABSTRACT. Previous work has developed a method for studying noninfinitesimal operational units, called “plantations,” with the Thüen model. In that model, increasing returns to scale generate large operational units, but the potential market power conferred by the scale economies is sidestepped as an issue. The present work introduces finite supply elasticities and examines their locational impacts. The profit-maximizing monopsonistic plantation is smaller, and the shipment distance for its processed output is shorter, than for a comparable competitive plantation. The present approach does not involve spatial competition strategies.  相似文献   
109.
110.
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