全文获取类型
收费全文 | 1037篇 |
免费 | 126篇 |
国内免费 | 6篇 |
专业分类
财政金融 | 46篇 |
工业经济 | 146篇 |
计划管理 | 271篇 |
经济学 | 148篇 |
综合类 | 78篇 |
运输经济 | 16篇 |
旅游经济 | 16篇 |
贸易经济 | 326篇 |
农业经济 | 47篇 |
经济概况 | 75篇 |
出版年
2024年 | 4篇 |
2023年 | 16篇 |
2022年 | 20篇 |
2021年 | 27篇 |
2020年 | 52篇 |
2019年 | 43篇 |
2018年 | 53篇 |
2017年 | 42篇 |
2016年 | 32篇 |
2015年 | 41篇 |
2014年 | 89篇 |
2013年 | 111篇 |
2012年 | 95篇 |
2011年 | 112篇 |
2010年 | 72篇 |
2009年 | 45篇 |
2008年 | 64篇 |
2007年 | 62篇 |
2006年 | 48篇 |
2005年 | 36篇 |
2004年 | 32篇 |
2003年 | 23篇 |
2002年 | 16篇 |
2001年 | 12篇 |
2000年 | 5篇 |
1998年 | 5篇 |
1997年 | 6篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1988年 | 1篇 |
1983年 | 1篇 |
排序方式: 共有1169条查询结果,搜索用时 156 毫秒
1.
当前小体积远端射频单元(Remote Radio Unit,RRU)主要是皮站级别的Pico-RRU,其重量和体积仍然难以满足掌上型的要求。为此,采用高集成度的AD9361芯片来实现长期演进(Long Term Evolution,LTE)宽带收发信机功能,配合时钟同步模块、放大器模块和控制接口电路等一起构建低成本的掌上型RRU。主要解决了基于AD9516的时钟同步、低相位噪声设计和高灵敏度接收机设计三个技术难点,成功实现了掌上型、高性能、低成本的设计目标。整个RRU样机尺寸为18 cm×10 cm×2 cm,质量约500 g,量产成本千元以内。测试表明,该RRU下行误差向量幅度(Error Vector Magnitude,EVM)小于3%,优于3GPP要求的8%;10 MHz带宽时上行接收机灵敏度优于3GPP要求的-93.5 dBm。 相似文献
2.
We generalize and extend the sequential model proposed by the resources and appropriation theory to explain the digital divide in the European Union plus the United Kingdom (EU27+UK). We measure the theoretical constructs of the model with data provided by the EU and test the theoretical predictions using a partial least squares structural equation model. We find support for the hypothesized relationships but find that the effects vary depending on the digital development level of countries. While education overall is the primary determinant of the social production of digital inequalities, a country's digital development level is crucial for less well-educated Europeans. These findings have theoretical and practical implications: (1) they call into question the homogeneity of the effect of causal relationships and the assumption that individuals differ only in terms of motivation, access, and digital skills, and (2) they indicate that socially disadvantaged Europeans benefit from living in more digitally developed countries. 相似文献
3.
介绍了未来高速移动通信新标准IEEE802.20的总体概况,具体分析了IEEE802.20的技术特性、系统参考结构以及系统的组成模型,并对IEEE802.20标准前景分析与展望进行了详细描述。 相似文献
4.
Rajan和Zingales提出了进入权理论,认为企业的权力来源于进入权,即对关键资源接触和使用的权力。本文结合会计师事务所的特征,在分析其关键资源的基础上,建议会计师事务所的股权应设置为财产股、岗位股、贡献股。 相似文献
5.
6.
7.
8.
Open access resources are frequently not managed efficiently, resulting in falling stock levels and a declining income for fishermen. In the late 1970's, the policy response to this problem was the implementation of 200-mile fishing zones, which enabled the European Union to formulate and implement the Common Fisheries Policy, aimed at (among other things) conservation and distribution of available stocks. In Germany, this shift from an open access regime towards a common property regime had favourable outcomes. The trend of falling prices was reversed. The conclusion was that intertemporal efficiency had increased as a result of (inter)governmental policy. Apparently, a wedge was formed between price and marginal harvesting costs, implying that scarcity rent had returned as a component of prices. 相似文献
9.
LEI Hong-zhen CHEN Hao XU Yi-ping LI Yun 《中国经济评论(英文版)》2007,6(3):41-48
The concept and the characteristic of spread spectrum technology of knowledge network based on information integration environment are given at first. And the basic principle of the wireless network of knowledge and information is recommended. Then a project alternatives using the spread spectrum technology and wireless network is given to build a across-the abroad knowledge network system. 相似文献
10.
This paper analyzes vertical restraints in relation to market access issues. In Section II we briefly review the recent three major trade conflicts between Japan and the USA in light of vertical restraints. In Section III we review the major policy lessons of the economics literature of vertical restraints, and analyze whether we need a special treatment for vertical restraints abroad for a market access reason. In Section IV we evaluate the policy options towards foreign foreclosure and suggest that nondiscriminatory application of foreign or home competition policy should be the mechanism to address such concern instead of trade policy actions such as voluntary import expansions. 相似文献