全文获取类型
收费全文 | 608篇 |
免费 | 43篇 |
国内免费 | 4篇 |
专业分类
财政金融 | 31篇 |
工业经济 | 65篇 |
计划管理 | 198篇 |
经济学 | 99篇 |
综合类 | 68篇 |
运输经济 | 4篇 |
旅游经济 | 2篇 |
贸易经济 | 101篇 |
农业经济 | 41篇 |
经济概况 | 46篇 |
出版年
2023年 | 9篇 |
2022年 | 11篇 |
2021年 | 13篇 |
2020年 | 16篇 |
2019年 | 12篇 |
2018年 | 22篇 |
2017年 | 19篇 |
2016年 | 15篇 |
2015年 | 22篇 |
2014年 | 56篇 |
2013年 | 60篇 |
2012年 | 54篇 |
2011年 | 78篇 |
2010年 | 57篇 |
2009年 | 32篇 |
2008年 | 28篇 |
2007年 | 31篇 |
2006年 | 18篇 |
2005年 | 22篇 |
2004年 | 18篇 |
2003年 | 14篇 |
2002年 | 9篇 |
2001年 | 9篇 |
2000年 | 7篇 |
1999年 | 9篇 |
1998年 | 9篇 |
1997年 | 2篇 |
1995年 | 1篇 |
1992年 | 1篇 |
1984年 | 1篇 |
排序方式: 共有655条查询结果,搜索用时 15 毫秒
1.
Protecting Innovation Through Patents and Trade Secrets: Evidence for Firms with a Single Innovation
Dirk Crass Francisco Garcia Valero Francesco Pitton 《International Journal of the Economics of Business》2019,26(1):117-156
AbstractThis paper analyzes the use and effectiveness of patents and trade secrets designed to protect innovation. While previous studies have usually considered patents and trade secrets as substitutes for one another, we investigate to what extent and in what situations the two protection methods are used jointly. We identify protection strategies for single innovation firms and hence overcome the assignment problem of existing empirical studies, that is, whether firms using both protection methods do so for the same innovation or for different innovations. Employing firm panel data from Germany, we find fairly few differences between the determinants for choosing secrecy and patenting. Single innovators that combine both strategies, 39% of the group, tend to aim at a higher level of innovation and act in a more uncertain technological environment. Firms combining both protection methods yield significantly higher sales with new-to-market innovations, providing some evidence for a complementarity of the two protection methods. 相似文献
2.
在单频网多播传输中,传统的全反馈动态功率分配数算法需要根据每个时隙反馈的用户瞬时信道信息进行实时的调整,所以造成了资源分配频率快、上行反馈开销大的缺点。为了克服这个缺点,提出了一个低复杂度、没有用户反馈的单频网多播开环半动态功率分配算法。首先在各小区等功率分配的假设下,根据单频网的形状信息算出各小区等价信道增益,然后再根据这个增益值,实现满足速率需求情况下的各小区功率分配。仿真结果显示,与全反馈的动态功率分配算法相比,该算法以一小部分性能损失为代价,大大减少了单频网的上行反馈和资源分配的开销,因此更适用于实际的单频网多播系统。 相似文献
3.
我国细胞治疗产业发展现状研究 总被引:1,自引:0,他引:1
中国在细胞治疗领域的基础研究位列世界前列,一些龙头企业正在积极进行相关技术的研发,加紧全产业链的布局,我国的细胞治疗产业正处于成功商业化和临床受益的爆发点。介绍了我国细胞治疗的市场环境、政策环境、国内外最新研究进展和我国细胞治疗行业代表企业的发展情况,提出了未来我国发展细胞治疗产业的关键挑战,并对今后的发展方向进行了展望。 相似文献
4.
5.
David G. Mayes 《Journal of Economic Policy Reform》2018,21(3):178-189
This article explores the problems the EU and the SRB face in trying to implement a credible system for resolving banks without the use of taxpayer funds as a key part of banking union that avoids the doom loop between indebted banks and indebted sovereigns. It finds that without clear examples of how the system works in practice it is very difficult to provide convincing evidence of what will happen given the large number of options for bailing in, the continuing predilection for bailing out in some states and the lack of fiscal backstop for general threats to financial stability. 相似文献
6.
杜广志 《中小企业管理与科技》2021,(6)
为降低铁路单线隧道接触网弓形腕臂预配施工难度,论文研究了一种接触网弓形腕臂预配平台,结合单线隧道内弓形腕臂数据精测技术及计算软件,精确测量预配,保证弓形腕臂的安装精度和质量,使弓形腕臂在现场施工中一次成优。论文结合实际,就某铁路单线隧道接触网弓形腕臂预配平台作具体分析。 相似文献
7.
Michael S. Garver 《Journal of Business Logistics》2019,40(1):30-43
To increase the relevance of logistics and supply chain academic research, this paper recommends the development and testing of middle‐range theory and practice‐level theory. Yet, there are a number of research issues that arise when academic researchers test middle‐range and practice‐level theory, both in measuring constructs and in testing theoretical relationships between constructs. Concerning the measurement of constructs, this paper recommends that academic researchers pay more attention to content validity and undertake rigorous processes to ensure content validity. In addition, academic researchers need to more explicitly define constructs as either reflective or formative. If the construct is defined as formative, then the traditional statistical approaches to validate these measurement scales are not recommended. The appropriate use of employing single‐item measures for concrete constructs is discussed. In regard to conducting hypothesis tests, research issues associated with multicollinearity and omitted variable bias are discussed. Relative weight analysis is ideal for testing theoretical models and research hypotheses when survey data are obtained, multicollinearity is present, and there are a large number of independent variables predicting a dependent variable. Thus, relative weight analysis is ideal for testing research hypotheses in logistics and supply chain management. 相似文献
8.
9.
通过对全封闭单托辊输送机的创新的优化设计,使得此设备在原有的设计基础上,在清扫器、单托辊、靴型料斗、头部耐磨衬板和轴承测温系统等方面进行进一步优化,使之在使用方面更加可靠,维护保养更加方便,实现了该设备的使用性能的又一次飞跃。 相似文献
10.
Mario Tonveronachi 《Journal of post Keynesian economics》2015,38(4):495-508
AbstractThe paper presents a reform proposal for the operations of the European Central Bank (ECB) whose purpose is to create a common set of risk-free assets for financial institutions operating in the euro area (EA), which is the necessary condition for having a single internal financial market. The proposal does not require the introduction of changes in the existing European Union treaties. The effects of this reform on the debt dynamic of EA member countries permit a revision of the existing fiscal rules. With the help of some simulations, it is shown that maintaining compliance with the European treaties, the reform of the ECB operations and revised fiscal rules would transform the current fiscal deflationary stance into a reflationary one. Some implications for aggregate demand and growth for the EA are briefly discussed. 相似文献