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   228篇
  免费   14篇
  2020年   2篇
  2019年   9篇
  2018年   12篇
  2017年   11篇
  2016年   10篇
  2015年   7篇
  2014年   11篇
  2013年   68篇
  2012年   6篇
  2011年   4篇
  2010年   8篇
  2009年   6篇
  2008年   7篇
  2007年   6篇
  2006年   5篇
  2005年   5篇
  2004年   4篇
  2003年   6篇
  2002年   2篇
  2001年   5篇
  2000年   3篇
  1999年   1篇
  1998年   2篇
  1997年   1篇
  1996年   1篇
  1995年   2篇
  1994年   2篇
  1991年   3篇
  1990年   1篇
  1989年   1篇
  1988年   1篇
  1987年   1篇
  1986年   2篇
  1985年   1篇
  1984年   1篇
  1983年   5篇
  1982年   3篇
  1981年   1篇
  1980年   2篇
  1979年   3篇
  1978年   2篇
  1977年   2篇
  1976年   2篇
  1974年   1篇
  1972年   1篇
  1971年   1篇
  1953年   1篇
  1952年   1篇
排序方式: 共有242条查询结果,搜索用时 15 毫秒
71.
72.
To investigate potential human impacts on California Channel Island shellfish stocks over the past 10,000 years, we measured 1718 owl limpet shells from 19 archaeological components on San Miguel Island. Inhabiting the middle intertidal zone of Pacific Coast rocky shores, owl limpets are slow-growing mollusks that can live for 30 years and reach lengths of over 100 mm. Recent ecological studies indicate that owl limpets are highly susceptible to heavy human predation, which results in reduced mean shell sizes among Lottia populations along the coasts of Alta and Baja California. On San Miguel Island, we identified a significant trans-Holocene reduction in mean owl limpet size, beginning more than 6500 years ago and accelerating at least 4400 years ago. Fluctuations in limpet size show no clear correlation with changes in sea surface temperature and marine productivity, suggesting that increased predation by growing human populations was primarily responsible for the reduction in Lottia size over time. Our results provide further evidence that prehistoric peoples significantly influenced nearshore fisheries long before the development of the commercial and industrialized fisheries of historic times.  相似文献   
73.
74.
During the 1950s, the United States Public Health Service prepared two statements on the link between smoking and lung cancer that have not been recognized by other historians. This article employs extended discussions of these two statements as vehicles to explore both internal developments at the federal health agency and larger questions surrounding the disciplinary emergence of chronic disease epidemiology. The primary cast of characters includes Surgeons General Leonard A. Scheele and Leroy E. Burney, Lewis C. Robbins (a lower-ranking Public Health Service officer, who had chief responsibility for the agency's smoking-related programs from 1958 through 1962 and who left behind a daily professional diary), and Journal of the American Medical Association (JAMA) editor John H. Talbott. These men, and others, are seen grappling (at varying levels of engagement) with the appearance of what we now recognize as a profoundly different way of understanding chronic disease causation, which centers on survey-taking and statistical analysis of risk factors.  相似文献   
75.
In his classic work about the Mediterranean in the period of Philipp II, French historian Fernand Braudel designates the European Alps an ‘exceptional range of mountains’ and offers several reasons therefor. In contrast to other parts of Braudel’s work, this argument has gone largely unnoticed in scholarship. This article intends to put it to the test in light of recent publications on the Alps. The first two sections give an outline of Braudel’s dealings with mountain regions and of historical research on the Alps from the 1970s onwards. The third section comments on the suitability of Braudel’s criteria for empirical assessments in a comparative perspective. In the conclusions it is argued that Braudel’s general intuition is still valid to some degree. It is less certain, however, that all the criteria are pertinent. More importantly, the findings emphasize the fact that the history of the Alps cannot be studied without paying close attention to their links with the surrounding lowlands. Thus the question of alpine exceptionality raises the question of the special trajectory of these lowland regions within the larger history of Europe.  相似文献   
76.
This paper seeks to extend geographic thinking on the changing constitution of the UK welfare state, suggesting the need to supplement ideas of the “shadow state” with an analysis of the blurring of the bureaucratic practices through which welfare is now delivered by public, private and third sector providers alike. Focusing on the growing convergence of the bureaucratic practices of benefits officials and food bank organisations, we interrogate the production of moral distance that characterise both. We reveal the ideological values embedded in voucher and referral systems used by many food banks, and the ways in which these systems further stigmatise and exclude people in need of support. Contrasting these practices with those of a variety of “ethical insurgents”, we suggest that food banks are sites of both the further cementing and of challenge to the injustices of Britain's new welfare apparatus.  相似文献   
77.
China's South–North Water Transfer Project (SNWTP) is a vast and still expanding network of infrastructure and institutions that moves water from the Yangtze River and its tributaries to cities in North China. This article aims to assess the SNWTP's impacts by beginning to answer seven questions about the project: How is the management of the SNWTP evolving? What are the problems to be resolved when managing SNWTP water within jurisdictions? What are the status and management of water quality in the SNWTP? What are the consequences of resettlements caused by the SNWTP? How is increased water supply affecting regional development? Is the SNWTP achieving its stated environmental goals? What are the sustainability credentials of the SNWTP? Drawing on primary and secondary data, the article demonstrates both that the opportunities and burdens characterising the project are highly uneven and that management systems are evolving rapidly in an attempt to enforce strict water quality targets. Furthermore, while the SNWTP may be helping to resolve groundwater overexploitation in Beijing, it is highly energy intensive, raising questions about its sustainability. Our analysis highlights the need to continue to interrogate the socio‐economic, environmental, and political implications of such schemes long after they are officially completed.  相似文献   
78.
The ‘Pacific Solution’ of transporting asylum seekers who arrive by boat in Australian waters to detention centres on Nauru and on Manus Island in Papua New Guinea (PNG) has attracted considerable international attention. Most of this has focused on the treatment of those detained and the morality, practicality and sustainability of Australian refugee policy. In this issue of ‘Pacific Currents’, we focus on the consequences for the Island nations. This article sets the scene for articles on Nauru and Manus Island by: 1. outlining the policy debates that led to the two phases of the ‘Pacific Solution’; 2. assembling data covering the numbers and costs involved; and 3. exploring the policy options in the wake of the PNG Supreme Court’s April 2016 ruling that the Manus Island centre was in violation of the constitution. All three papers are particularly concerned to explore the domestic political and legal ramifications of the centres for Nauru and PNG, and to examine the impact on Australia’s reputation in the Pacific region.  相似文献   
79.
This article examines what a critical focus on the region can contribute to the study of LGBTQ politics in Europe. It is argued that a regional lens can challenge methodological nationalism in existing studies of European LGBTQ politics. It can also contribute towards a broader examination of the politics of scale in relation to the Europeanisation of LGBTQ politics. The article discusses alternative theoretical approaches to the region and examines the queer affinities of these approaches in turn. The argument proceeds to consider the political effects of these alternative theoretical framings of the region in contemporary LGBTQ politics in Europe. It is suggested that a regional critical lens can foreground sub-national and transnational regional political formations, which otherwise may be overlooked in an uncritical focus on the national scale of LGBTQ politics. A regional perspective can also help unsettle Anglo-American framings of sexual politics.  相似文献   
80.
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