全文获取类型
收费全文 | 4670篇 |
免费 | 193篇 |
出版年
2020年 | 49篇 |
2019年 | 87篇 |
2018年 | 109篇 |
2017年 | 141篇 |
2016年 | 142篇 |
2015年 | 116篇 |
2014年 | 107篇 |
2013年 | 1741篇 |
2012年 | 113篇 |
2011年 | 128篇 |
2010年 | 121篇 |
2009年 | 126篇 |
2008年 | 85篇 |
2007年 | 143篇 |
2006年 | 114篇 |
2005年 | 57篇 |
2004年 | 62篇 |
2003年 | 55篇 |
2002年 | 64篇 |
2001年 | 48篇 |
2000年 | 48篇 |
1999年 | 45篇 |
1998年 | 54篇 |
1997年 | 57篇 |
1996年 | 29篇 |
1995年 | 44篇 |
1994年 | 29篇 |
1993年 | 32篇 |
1992年 | 35篇 |
1991年 | 24篇 |
1990年 | 30篇 |
1989年 | 27篇 |
1988年 | 37篇 |
1987年 | 43篇 |
1986年 | 32篇 |
1985年 | 48篇 |
1984年 | 50篇 |
1983年 | 50篇 |
1982年 | 52篇 |
1981年 | 47篇 |
1980年 | 47篇 |
1979年 | 48篇 |
1978年 | 45篇 |
1977年 | 46篇 |
1976年 | 39篇 |
1975年 | 38篇 |
1974年 | 15篇 |
1973年 | 27篇 |
1972年 | 25篇 |
1971年 | 16篇 |
排序方式: 共有4863条查询结果,搜索用时 15 毫秒
91.
Blue glass trade beads from well-dated late seventeenth- to early twentieth-century sites and collections have been analysed non-destructively by instrumental neutron activation analysis. The beads display enough variations in their elemental contents to allow us to characterize the different chemistries. The implication of these results is that similar chemical analyses of blue beads from undated archaeological sites may be used to help date the sites, since each bead chemistry has a specific earliest period. 相似文献
92.
Fifty-three copper-based metal fragments, recovered from the Robitaille site in southcentral Ontario, were analysed by neutron activation to establish their chemical make-up and to sort them by their trace elemental chemistries. Three different European copper samples, one brassy copper and 48 brass samples with five different chemistries were found. As few as eight trading actions may account for all of the recovered European metal fragments. 相似文献
93.
John Tomaney 《European Planning Studies》1995,3(1):99-113
This paper reviews recent developments in Irish policy and the debates and controversies that have surrounded these developments. While Irish industrialization has been dependent since the 1950s on the attraction of foreign direct investment (FDI), since the beginning of the 1980s analyses and policies have tended to emphasize the importance of promoting the indigenous sector. While there is some evidence that this shift in emphasis was associated with an improvement in Irish industrial performance, the most recent review of industrial policy called for a further shift in the direction of support for indigenous enterprise. Some implications of these recommendations are discussed, especially as they pertain to debates surrounding the achievement of cohesion in the European Union. 相似文献
94.
John Friedmann 《European Planning Studies》1995,3(3):275-285
International migration into European cities has stirred a great deal of debate about appropriate national policies. But the planning literature has been remarkably silent on the issues involved, particularly as immigration affects urban conditions. This paper is a first attempt to delineate the problems and to suggest ways that planners can contribute to the economic, socio‐cultural and political integration of international migrants at the local level. 相似文献
95.
Shirley V. Scott 《Australian journal of political science》1995,30(2):288-299
Current theoretical understanding of compliance with international law is based on an assumption that international law consists of a finite set of objective, compulsory rules. This image does not match reality but the two can be reconciled through theorising international law as ideology. Such an approach subsumes questions as to why states do or do not obey law and what influence international law has on foreign policy decision making. By placing the relationship of state behaviour to international law in a broader perspective it can account for previously identified determinants of compliance and provide a basis on which to assess their relative significance. At the same time, the research agenda regarding compliance is broadened by the introduction of fresh questions. 相似文献
96.
John Coates Seán McGrail David Brown Edwin Gifford Gerald Grainge Basil Greenhill Peter Marsden Boris Rankov Colin Tipping Edward Wright 《International Journal of Nautical Archaeology》1995,24(4):293-301
The need for experiments to study physical aspects of craft of the past is stated, as well as the necessity for them to have clear aims and to follow the established principles of scientific enquiry. These principles are discussed in this joint paper by ten maritime archaeologists and others, together with methods and some points of management critical to their application in this field. 相似文献
97.
98.
99.
Radiocarbon Chronology of the Siberian Paleolithic 总被引:2,自引:0,他引:2
We have compiled 462 C-14 determinations for 120 Paleolithic and Mesolithic sites from Siberia and the Russian Far East. The Mousterian sites are dated to ca. 46,000–28,500 BP. The Middle–Upper Paleolithic transition dates to ca. 43,300–28,500 BP. Although there are a few earlier sites, most of the Upper Paleolithic sites are dated to the time interval between ca. 34,000 BP and 10,000 BP. The earlier Upper Paleolithic stage is characterized by macroblade technology and is radiocarbon-dated to ca. 34,000–20,000 BP. The earliest microblade technology occurs in the late stage of the Upper Paleolithic, dated to ca. 23,000–20,000 BP, but the majority of microblade sites is dated to ca. 20,000–11,000 BP. The Final Paleolithic (Mesolithic) sites date to ca. 12,000–6000 BP. At ca. 13,000–11,000 BP, the earliest Neolithic appeared in both the Russian Far East (Amur River basin) and the Transbaikal. The Paleolithic–Neolithic transition occurred ca. 13,000–6000 BP. 相似文献
100.