全文获取类型
收费全文 | 648篇 |
免费 | 231篇 |
国内免费 | 80篇 |
出版年
2023年 | 6篇 |
2022年 | 7篇 |
2021年 | 17篇 |
2020年 | 15篇 |
2019年 | 14篇 |
2018年 | 12篇 |
2017年 | 29篇 |
2016年 | 45篇 |
2015年 | 17篇 |
2014年 | 43篇 |
2013年 | 56篇 |
2012年 | 50篇 |
2011年 | 53篇 |
2010年 | 27篇 |
2009年 | 66篇 |
2008年 | 46篇 |
2007年 | 43篇 |
2006年 | 60篇 |
2005年 | 49篇 |
2004年 | 39篇 |
2003年 | 45篇 |
2002年 | 41篇 |
2001年 | 35篇 |
2000年 | 17篇 |
1999年 | 15篇 |
1998年 | 15篇 |
1997年 | 11篇 |
1996年 | 19篇 |
1995年 | 13篇 |
1994年 | 14篇 |
1993年 | 8篇 |
1992年 | 19篇 |
1991年 | 3篇 |
1990年 | 6篇 |
1989年 | 3篇 |
1988年 | 1篇 |
排序方式: 共有959条查询结果,搜索用时 15 毫秒
871.
AVL系统就是GIS与GPS技术集成的成功应用。AVL系统中GPS信号在GIS地图上显示时,由于各种因素的影响,存在很大的偏差。对这种偏差的校正是十分必要的。为了解决这个问题,对以前提出的误差校正算法———"线性抽象算法"进行了改进,提出了另一种误差校正方法———"缓冲区线性抽象算法",实验结果表明这种方法能在很大程度上校正偏差,不但具有较高的精度,而且还提高了算法效率。 相似文献
872.
873.
在相对运动平台的点对点通信中,天线如何快速、准确地进行跟踪对准是接收高质量通信信号的保证.针对于动态点对点通信中定向天线对准难的问题,提出了一种基于坐标跟踪法和信号跟踪法的联合天线跟踪控制法,并对此方法进行了系统的软、硬件设计.通过精度分析和试验得出该方法对准精度高,系统易于实现,能够满足微波通信天线对准工程实现中的快与准的要求. 相似文献
874.
875.
目的将直观的外科手术影像资料应用于护理本科生的《外科护理学》课堂教学中,探讨其对学生掌握相关理论知识程度的影响,探寻一种新的、更有效的外科护理专业授课模式。方法将同一年级的131名护本生按班级随机分为对照组(1班,4班,共65例)和实验组(2班,3班,共66例),对照组按照传统教授为主的教学模式实施课堂教学;实验组将外科手术影像资料结合教科书内容运用于课堂教学。结果实验组学生的理论授课后当堂测试成绩高于对照组;理论授课三个月后,试验组理论测试成绩明显高于对照组,实验组与对照组成绩之间的差异有统计学意义(P〈0.05)。结论将直观的外科手术影像资料运用于《外科护理学》课堂教学的授课模式,对护理本科生掌握相关理论知识程度的影响优于传统的教学模式。 相似文献
876.
W. Struys 《Defence and Peace Economics》2013,24(1):75-76
La Conversion économique du secteur militaire, J. FONTANEL, Economica, Paris, 1994, pp. 112. Paperback. ISBN 2–7178–2650–5. 相似文献
877.
For a three‐sector Feder‐Ram framework, we present time‐series, cross‐sectional estimates for two cohorts, consisting of Asian and Latin American countries. The estimates indicate that private investment, and defense and non‐defense public spending are growth promoting for alternative error components representations. For the best error components representation, greater growth enhancement is associated with the two forms of public spending in Asia than in Latin America, while the opposite comparison characterizes private investment. Although defense is growth promoting, an opportunity cost exists insofar as non‐defense spending, financed by defense spending, appears to give a small net boost to growth in Latin America. 相似文献
878.
Defence expenditures have both costs and benefits to the economy. The costs of defence expenditures are mainly emphasized as opportunity costs. On the other hand, defence spending may have growth‐promoting potential benefits: a rise in defence spending may result in a higher aggregate demand, production and employment. This paper examines empirically the effects of military expenditures on economic growth for Middle Eastern countries and Turkey, for the time‐period 1989–1999. The relationship between military expenditure and economic growth is investigated by using cross‐section and dynamic panel estimation techniques. Empirical analysis indicates that military expenditure enhances economic growth in the Middle Eastern countries and Turkey as a whole. 相似文献
879.
Sakiru Adebola Solarin 《Defence and Peace Economics》2013,24(7):853-870
AbstractAnecdotal evidence offers conflicting views on the impact of globalisation on military expenditure. We contribute to the existing literature by investigating the effect of globalisation on military expenditure in 82 countries for the period, 1989–2012. After introducing economic and strategic variables into the model, we utilise the dynamic panel generalised method of moments system to estimate the relationship in the variables. The empirical findings reveal that globalisation reduces both military burden and real military expenditure. The findings are consistent, irrespective of the globalisation indicator adopted. The policy implications of the results are explained. 相似文献
880.
AbstractWhile not always a concern for the general economic growth literature, the debate over the effects of military spending on growth continues to develop, with no consensus, but a deepening understanding of the limitations of previous work. One important issue that has not been adequately dealt with is the endogeneity of military spending in the growth equation, mainly because of the difficulty of finding any variables that would make adequate instruments. This paper considers this issue, using an endogenous growth model estimated on a large sample of 109 non-high-income countries for the period 1998–2012. The empirical analysis is framed within an instrumental variable setting that exploits the increase in military spending that occurs when unrest in a country escalates to turmoil. The estimation results show that endogeneity arising from reverse causality is a crucial issue, with the instrumental variable estimates providing a larger significant negative effect of military spending on growth than OLS would. This result is found to be robust to different sources of heterogeneity and different time periods. 相似文献