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   2557篇
  免费   124篇
  2681篇
  2023年   21篇
  2022年   11篇
  2020年   55篇
  2019年   58篇
  2018年   82篇
  2017年   76篇
  2016年   112篇
  2015年   82篇
  2014年   73篇
  2013年   602篇
  2012年   74篇
  2011年   103篇
  2010年   86篇
  2009年   81篇
  2008年   78篇
  2007年   73篇
  2006年   64篇
  2005年   51篇
  2004年   51篇
  2003年   33篇
  2002年   45篇
  2001年   56篇
  2000年   25篇
  1999年   35篇
  1998年   20篇
  1997年   25篇
  1996年   18篇
  1995年   23篇
  1994年   22篇
  1993年   29篇
  1992年   23篇
  1991年   13篇
  1990年   18篇
  1988年   27篇
  1987年   24篇
  1986年   25篇
  1985年   24篇
  1984年   35篇
  1983年   21篇
  1982年   23篇
  1981年   26篇
  1980年   25篇
  1979年   20篇
  1978年   20篇
  1977年   19篇
  1976年   21篇
  1974年   12篇
  1973年   14篇
  1972年   21篇
  1970年   12篇
排序方式: 共有2681条查询结果,搜索用时 15 毫秒
941.
Vijaya, Prasad, G.V.R. & Singh, K., June, 2009. Late Triassic palynoflora from the Pranhita–Godavari Valley, India: evidence from vertebrate coprolites. Alcheringa 33, 91–111. ISSN 0311-5518.

The Upper Triassic Maleri Formation, represented by red clays and sandstones, has to date not produced any plant macrofossils or palynomorphs. Many spiral and non-spiral coprolites collected during this study from the Maleri Formation of the Pranhita-Godavari Valley were analysed for palynomorphs. Based on shape, nature of coiling and size, the Maleri coprolites are classified into seven groups. Of these, only Group-I, Type 5 (non-spiral) and amphipolar (spiral) types yielded diverse gymnospermous and pteridophytic spores, pollen, other plant debris and sparse fungal spores and algal remains. Occurrences of Antulsporites varigranulatus, Aratrisporites spp., Cadargasporites baculatus, Dubrajisporites isolatus, Enzonalasporites vigens, Foraminisporis coelatus, Grandispora spinosa, Kraeuselisporites saeptatus, Polycingulatisporites reduncus, Staurosaccites spp., Tethysispora unica and Tikisporites balmei confirm a Late Triassic age for the coprolite-bearing red clays. Records of Classopollis classoides and Callialasporites turbatus/dampieri in these assemblages more precisely suggest a Norian to Rhaetian age. The non-spiral coprolites were possibly produced by aquatic piscivorous animals whereas the spiral coprolites may have been produced by an as yet unidentified fish taxon. The coprolite-producing animals (spiral and non-spiral groups) possibly ingested gymnospermous and pteridophytic plant remains passively along with water or their herbivorous prey.  相似文献   
942.
Jurij Borys. The Sovietization of Ukraine, 1917–1923. The Communist Doctrine and Practice of National Self-Determination. Revised edition. Edmonton: The Canadian Institute of Ukrainian Studies, 1980. Pp. xxii, 488; Vera S. Dunham. In Stalin's Time. Middle-class Values in Soviet Fiction. Introduction by Jerry F. Hough. First paperback edition. Cambridge: Cambridge University Press, 1979. Pp. xiv, 283; Taras Hunczak, editor. The Ukraine, 1917–1921: A Study in Revolution. Introduction by Richard Pipes. Cambridge, MA: Harvard Ukrainian Research Institute, 1977. Pp. viii, 424; Roy Medvedev, The October Revolution. Foreword by Harrison E. Salisbury. New York: Columbia University Press, 1979. Pp. xix, 240; Rosalind Mitchison, editor. The Roots of Nationalism: Studies in Northern Europe. Edinburgh: John Donald Publishers Ltd., 1980. Pp. vii, 175; Peter J. Potichnyj, editor. Poland and Ukraine, Past and Present. Edmonton: The Canadian Institute of Ukrainian Studies, 1980. Pp. xiv, 365; Edward C. Thaden, editor. Russification in the Baltic Provinces and Finland, 1855–1914. Princeton: Princeton University Press, 1981. Pp. xiii, 497; Anthony F. Upton. The Finnish Revolution, 1917–1918. Minneapolis: University of Minnesota Press, 1980. Pp. v, 608.  相似文献   
943.
Book reviews     

James E. McClellen III and Harold Dorn. Science and Technology in World History: An Introduction. Baltimore and London: Johns Hopkins Press, 1999.404 pages + illustrations + maps + graphs + bibliography + index. $55.00 (hardcover), $18.95 (paperback).

Arnold Pacey. Meaning in Technology (Cambridge, Mass and London, England: MIT Press, 1999), pp. viii+264.  相似文献   
944.
WILLIAM R. THOMPSON. The Emergence of the Global Political Economy. London and New York: Routledge, 2000. Pp. xi, 252. $25.99 (US), paper; DEREK H. ALDCROFT and ANTHONY SUTCLIFFE, eds. Europe in the International Economy, 1500–2000. Cheltenham and Northampton, Mass.: Edward Elgar Publishing, 1999. Pp. xi, 289. $90.00 (US); KENNETH POMERANZ. The Great Divergence: Europe, China, and the Making of the Modern World Economy. Princeton: Princeton University Press, 2000. Pp. x, 382. $39.95 (US).  相似文献   
945.
Abstract

The translation to meaning of Psalm 82 changed through time and tradition. The polytheistic world of the author of the poem was not the accepted context for understanding the psalm when it was considered as part of the Bible. Jewish and Christian readings of the same text have traditionally been quite different. Examples of various understandings of the psalm from the author's to the Reformation's are presented to demonstrate that the official meaning of the biblical text actually has been different according to the tradition in which it has been read.  相似文献   
946.
The accompanying articles that speculate that Alexander the Great had a traumatic carotid dissection or congenital cervical scoliosis demonstrate the difficulties in retrospective diagnosis as a historical enterprise. The extant primary sources were written centuries after Alexander’s death and are ambiguous in their original languages, and even more so in translation. Thus we cannot be certain what illness Alexander actually had. Furthermore, anachronistic diagnosis removes Alexander from the medical context of this time, telling us little of historical significance about him. Such investigations also illustrate the more general limits that the absence of context imposes on the study of ancient history.  相似文献   
947.
Abstract

The aim of the study is to draw attention to the existence of a Neolithic figurine from Greece with characteristics compatible with Down syndrome. We have reviewed the relevant medical and archaeological literature, and we have compared photographs of the figurine with photographs of a patient with typical Down syndrome (DS). From the above data we conclude that the 7000 years old artefact may well be the most ancient representation of the disease in Western civilisation.  相似文献   
948.
Abstract

Heinrich Klüver and Paul Bucy described a constellation of symptoms in monkeys following large resections of the temporal lobe that they termed the “temporal lobe syndrome”; now commonly referred to as the Klüver‐Bucy syndrome. The aim of this paper is threefold: (1) to review Heinrich Klüver's behavioral studies on monkeys that led up to his temporal lobe experiments with Paul Bucy; (2) to understand why Brown and Schäfer dismissed the behavioral changes in temporal lobe monkeys they had observed fifty years prior to the studies of Klüver and Bucy; and (3) to show that Klüver's phenomenologically motivated conceptual paradigm helped to unify both neuropsychological and neuroanatomical theories regarding the visual and emotive functions of the non‐human primate temporal lobe.  相似文献   
949.
The Baden-Württemberg shoreline of Lake Constance and the lakes and moors of Upper Swabia contain important prehistoric wetland sites. From 1979, new research has brought up not only important finds and scientific results but also increasing information about bank erosion in the lakes and desiccation in the moorlands. At Lake Constance, early attempts were made in the 1980s to protect sites threatened by erosion by covering them with geo-textile and gravel. With further protective projects the know-how improved, but crucial questions still remained: What are the best practical solutions? How about ecological compatibility? Do we have other options? The INTERREG IV 2008–2011 international project ‘Erosion and Archaeological Heritage Protection in Lake Constance and Lake Zurich’ brought deeper insights and opened the field for new experiments with protective measures. At the Federsee Moor a long-term project started in 1980 with close collaboration between nature conservation and archaeological heritage management. With archaeological stocktaking, acquisition of land, establishment of new nature reserves, exchange of landholding and hydrographic engineering, the project was completed with the help of European Union funding by LIFE+in 2013.  相似文献   
950.
Axel Körner 《Modern Italy》2013,18(2):137-162
Since the early nineteenth century political opposition became a central concept of political representation in constitutional monarchies. While this concept marked the political language of unified Italy on the national level, in local administration the legitimacy of political opposition remained an issue of dispute, as illustrated in this analysis of the political language in Bologna's local council. Local perceptions of national events, like the government's reaction to Garibaldi's unsuccessful Mentana-campaign, assumed major symbolic meaning in local politics and challenged traditional understandings of municipal administration by introducing the concept of political opposition. In Bologna, after Rome the second city of the former Papal State, the Moderates were able to grow into a position of political hegemony after the Unification of Italy and remained the predominant political force also after Italy's “parliamentary revolution” of 1876 and the electoral reforms of the 1880s. As a consequence of its limited influence on the local administration, Bologna's Left defined its ideological profile earlier and more clearly than the Left in other parts of Italy and integrated issues of national importance into local political discourse. Analysing the relationship between central administration and periphery, the article reveals the development of political language and the changing meanings of political representation between Unification and World War One and explains on this basis the escalation of social and political conflict in Finesecolo Italy.  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