全文获取类型
收费全文 | 5615篇 |
免费 | 260篇 |
出版年
2023年 | 32篇 |
2020年 | 77篇 |
2019年 | 115篇 |
2018年 | 149篇 |
2017年 | 179篇 |
2016年 | 208篇 |
2015年 | 156篇 |
2014年 | 140篇 |
2013年 | 1636篇 |
2012年 | 132篇 |
2011年 | 163篇 |
2010年 | 162篇 |
2009年 | 165篇 |
2008年 | 144篇 |
2007年 | 126篇 |
2006年 | 115篇 |
2005年 | 64篇 |
2004年 | 81篇 |
2003年 | 75篇 |
2002年 | 69篇 |
2001年 | 81篇 |
2000年 | 83篇 |
1999年 | 69篇 |
1998年 | 58篇 |
1997年 | 66篇 |
1996年 | 44篇 |
1995年 | 55篇 |
1994年 | 44篇 |
1993年 | 56篇 |
1992年 | 44篇 |
1991年 | 53篇 |
1990年 | 45篇 |
1989年 | 52篇 |
1988年 | 43篇 |
1987年 | 56篇 |
1986年 | 49篇 |
1985年 | 70篇 |
1984年 | 63篇 |
1983年 | 70篇 |
1982年 | 54篇 |
1981年 | 46篇 |
1980年 | 55篇 |
1979年 | 58篇 |
1978年 | 52篇 |
1977年 | 55篇 |
1976年 | 63篇 |
1975年 | 42篇 |
1974年 | 41篇 |
1973年 | 35篇 |
1972年 | 32篇 |
排序方式: 共有5875条查询结果,搜索用时 15 毫秒
991.
992.
993.
994.
995.
Robert Michael Bridi 《对极》2013,45(5):1070-1089
International labour migration programs provide a vulnerable workforce that services various sectors in developed economies. The agriculture sector is one arena in which the employment of migrant workers has become more pervasive. Annually, approximately 30,000 workers are employed in the Canadian agriculture sector through the Seasonal Agricultural Workers Program (SAWP). In this paper, I focus on the SAWP workers in tobacco farming, and investigate the ways that labour control is achieved on two small‐scale farms. I draw upon original empirical evidence from interviews with three Mexican and nine Jamaican workers, two union representatives, and two farm owners in South‐Western Ontario, Canada. My findings show that various factors at multiple scales shape the labour control regime and significantly advantage farm owners over workers. Based on my findings, I argue that the labour control regime is conditioned exogenously by multi‐scalar factors and generated endogenously at the point of production. 相似文献
996.
Amy L. Fletcher 《History & Technology》2013,29(2):103-119
National communication systems--while they serve a universal human need--do not follow a universal logic of development. Instead, networks emerge from the interaction of ideas, culture, and politics within specific national contexts. This article develops a culturally and politically grounded analysis of technology via an exploration of the videotex saga in France; the only large advanced industrialized state where videotex succeeded. Particular attention is given to the way in which the French government designed videotex as a public strategy not only to modernize the telecommunications network, but also to bolster French economic and national security in relation to the United States. The article concludes that French videotex provides strong support for the thesis that communications technologies resolve and reflect unique cultural and political dilemmas, in addition to fulfilling their more technocratic function as scientific/engineering projects. 相似文献
997.
Robert Gardner 《History & Technology》2013,29(4):325-341
The turbulent climate of the Great Plains made windbreaks necessary for the protection of settlers and their livestock and crops. At first individual farmers tried to plant their own shelterbelts but with little success. The US Forest Service, with the establishment of the Bessey tree nursery, in 1902, and the field planting of the Nebraska National Forest, developed the expertise to carry out farm forestry on the plains. In 1934 the Forest Service undertook the Prairie States Forestry Project, an eight‐year program to plant shelterbelts from Canada to Texas, in response to the Dust Bowl and the Great Depression. These shelterbelts were a technological solution to environmental and social problems. As they grew, successful shelterbelts developed forest characteristics and served as habitat for birds and wildlife. As systems that were both technical and ecological, shelterbelts embodied a confluence of culture and nature in the technology that farmers and foresters used to engineer a more suitable environment for American society on the Plains. 相似文献
998.
999.
1000.