全文获取类型
收费全文 | 7246篇 |
免费 | 273篇 |
专业分类
7519篇 |
出版年
2020年 | 97篇 |
2019年 | 139篇 |
2018年 | 157篇 |
2017年 | 184篇 |
2016年 | 228篇 |
2015年 | 158篇 |
2014年 | 153篇 |
2013年 | 2091篇 |
2012年 | 208篇 |
2011年 | 220篇 |
2010年 | 246篇 |
2009年 | 218篇 |
2008年 | 195篇 |
2007年 | 197篇 |
2006年 | 191篇 |
2005年 | 101篇 |
2004年 | 92篇 |
2003年 | 90篇 |
2002年 | 97篇 |
2001年 | 110篇 |
2000年 | 78篇 |
1999年 | 95篇 |
1998年 | 63篇 |
1997年 | 56篇 |
1996年 | 70篇 |
1995年 | 73篇 |
1994年 | 72篇 |
1993年 | 80篇 |
1992年 | 71篇 |
1991年 | 59篇 |
1990年 | 52篇 |
1989年 | 66篇 |
1988年 | 56篇 |
1987年 | 65篇 |
1986年 | 64篇 |
1985年 | 76篇 |
1984年 | 65篇 |
1983年 | 94篇 |
1982年 | 70篇 |
1981年 | 72篇 |
1980年 | 68篇 |
1979年 | 67篇 |
1978年 | 71篇 |
1977年 | 63篇 |
1976年 | 72篇 |
1975年 | 66篇 |
1974年 | 53篇 |
1973年 | 54篇 |
1972年 | 55篇 |
1970年 | 44篇 |
排序方式: 共有7519条查询结果,搜索用时 0 毫秒
121.
ABSTRACT. Average monthly price data from twelve hinterland markets and the Houston port price for wheat are studied in a cointegration framework using the Engle-Granger "two-step" procedure and Johansen's maximum likelihood procedure. Out-of-sample forecasts from an error correction model are compared to those from a vector autoregression fit to levels and a univariate autoregression fit to first differences. This comparison suggests that modeling these (cointegrated) data as a levels vector autoregression, rather than as an error-correction process, results in significantly higher error bias, but lower error variance, at long horizons. 相似文献
122.
James A. Bill 《Iranian studies》1993,26(3-4):403-406
123.
The US. and France have adopted contrasting models of motor fuel tax and highway finance policy. Fuel tax revenues are dedicated to state and federal highway funds in America, keeping taxes quite low, but preventing them from contributing to the general treasury. French motor fuel taxes are higher and make up nearly 11 percent of the central government's general revenues, excluding social security contributions. French highway finance relies heavily on tolls. Pressure from the US. federal deficit has reduced the highway trust fund's ability to protect highway spending from budgetary competition. Political and procedural changes in Congress make it likely that the U.S.will move away from exclusive dedication of motor fuel taxes. 相似文献
124.
Laura A. Reese 《政策研究杂志》1993,21(3):492-506
In examining local economic development incentives, scholars have found it useful to employ typologies of development practices. Such typologies have been based on assumptions that techniques reflect functional categories, such as marketing and financial incentives, or can be organized by the nature of costs and benefits, or by the nature of incentive goals. While useful heuristic devices, little effort has been made to test these typologies empirically. This research note provides an empirically based typology of local economic development incentives, using data from 967 cities collected by the International City Management Association. 相似文献
125.
126.
127.
128.
129.
This paper questions the history of runrig townships in the western Highlands and Islands of Scotland. It challenges assumptions still held about their archaism and draws attention to the fact that many townships in the region show signs of having once been enclosed. It argues that these systems of enclosure, together with evidence for a more diffused system of settlement, constitute the pre-runrig landscape and further argues that the shift into runrig did not begin until the closing years of the medieval period. 相似文献
130.
A.J. Paolini 《Australian journal of political science》1993,28(1):98-117
The work of Michel Foucault highlights the need to rethink the assumptions of disciplines such as international relations which have tended to remain narrow, universalist and positivist. In particular, the key concept of power has largely escaped critical inquiry. This article seeks to open up the power discourse in international relations by exploring the limits of traditional approaches such as realism and even critical theory, arguing for a ‘post‐positivist’ approach which incorporates Foucault's insights into the nature of power. Indeed, it goes beyond much of the ‘Third Debate’ in directly focusing on power and rearticulating its form and content as a category of analysis in international relations. 相似文献