全文获取类型
收费全文 | 2008篇 |
免费 | 27篇 |
专业分类
2035篇 |
出版年
2021年 | 12篇 |
2020年 | 24篇 |
2019年 | 36篇 |
2018年 | 47篇 |
2017年 | 42篇 |
2016年 | 69篇 |
2015年 | 41篇 |
2014年 | 38篇 |
2013年 | 551篇 |
2012年 | 70篇 |
2011年 | 73篇 |
2010年 | 67篇 |
2009年 | 71篇 |
2008年 | 47篇 |
2007年 | 65篇 |
2006年 | 58篇 |
2005年 | 28篇 |
2004年 | 22篇 |
2003年 | 19篇 |
2002年 | 18篇 |
2001年 | 19篇 |
2000年 | 16篇 |
1999年 | 28篇 |
1998年 | 13篇 |
1997年 | 15篇 |
1996年 | 18篇 |
1995年 | 17篇 |
1994年 | 12篇 |
1993年 | 19篇 |
1992年 | 17篇 |
1991年 | 23篇 |
1988年 | 18篇 |
1987年 | 19篇 |
1986年 | 23篇 |
1985年 | 17篇 |
1984年 | 18篇 |
1983年 | 19篇 |
1982年 | 25篇 |
1981年 | 19篇 |
1980年 | 15篇 |
1979年 | 16篇 |
1978年 | 18篇 |
1977年 | 15篇 |
1976年 | 15篇 |
1975年 | 16篇 |
1973年 | 12篇 |
1970年 | 16篇 |
1969年 | 14篇 |
1968年 | 12篇 |
1967年 | 17篇 |
排序方式: 共有2035条查询结果,搜索用时 0 毫秒
61.
This paper identifies four triggers that underpinned the late 20th century reform of coastal management in Australia. These have operated across federal, state and local levels of government. The triggers are global environmental change, sustainable development, integrated resource management, and community awareness of management issues and participation in decision making. This reform has been driven by international and national forces. A number of inquiries into coastal management in Australia culminated in the production of a national coastal policy in 1995. This has led to fundamental changes in coastal management and to the recognition of the inevitability of changes in coastal systems. Federal policies and programs are being translated into action at the state and local government levels through a variety of funding mechanisms and programs. These involve capacity building, a memorandum of understanding between all levels of government, an enhanced role for state advisory or co‐ordinating bodies, and an increased role for public participation. 相似文献
62.
A. N. SHUGAR 《Archaeometry》2000,42(2):375-384
This paper presents the results of analysis of Byzantine opaque red glass tesserae derived from three separate locations in the ancient city of Beit Shean, Israel. Investigation proceeded using reflective light microscopy, energy dispersive X‐ray fluorescence and energy dispersive scanning electron microscopy. The glass matrix of the tesserae was found to be heterogeneous, with many inclusions. Similarities and differences between tesserae from the two mosaics are examined and discussed. Implications for locale of manufacture and production techniques are considered. Comparisons between the three locations led to conclusions about the use of the tunnel as a storage site and the implications of this for future research on mosaics. 相似文献
63.
64.
Summary. This paper describes a study of neutron activation analyses of some medieval tiles from the North Midlands. Having established the feasibility of the method of analysis, we applied a number of multivariate statistical techniques to derive eleven reference groups, each consisting of tiles with similar compositions which could plausibly have originated from the same source of clay. While known kiln sites could be readily distinguished, less confidence could be placed on the results where it was suspected that several sources had been mixed. Design information on the tiles when combined with the analytical results has led to the conclusion that stamps may have been passed from one tilery to another, though in some cases the tiles themselves were moved. The reference groups have proved to be useful in our continuing research on the composition of tiles from this area. 相似文献
65.
66.
67.
68.
69.
Discrete-choice theory and logit models are evaluated for their usefulness in analyzing migration patterns in a zonal system. The authors "argue that spatial effects and more specifically the relative location of zones are not taken into account in such analyses. We, therefore, introduce a measure of spatial structure and advocate its usage as a predictor of migration in such models. In an example of intrametropolitan migration in Toronto [Canada], we demonstrate that this variable is not only significant but also it improves the performance of all the other variables with the greatest impact on the distance between zones. In addition, inclusion of this variable improves the overall performance of the model in terms of residuals." 相似文献
70.