首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   4605篇
  免费   327篇
  国内免费   64篇
财政金融   355篇
工业经济   239篇
计划管理   1079篇
经济学   452篇
综合类   580篇
运输经济   55篇
旅游经济   141篇
贸易经济   1563篇
农业经济   152篇
经济概况   379篇
信息产业经济   1篇
  2024年   14篇
  2023年   47篇
  2022年   44篇
  2021年   149篇
  2020年   155篇
  2019年   110篇
  2018年   132篇
  2017年   164篇
  2016年   108篇
  2015年   123篇
  2014年   321篇
  2013年   639篇
  2012年   370篇
  2011年   490篇
  2010年   349篇
  2009年   258篇
  2008年   307篇
  2007年   219篇
  2006年   183篇
  2005年   187篇
  2004年   144篇
  2003年   126篇
  2002年   123篇
  2001年   79篇
  2000年   33篇
  1999年   21篇
  1998年   15篇
  1997年   16篇
  1996年   9篇
  1995年   12篇
  1994年   7篇
  1993年   9篇
  1992年   6篇
  1991年   5篇
  1989年   2篇
  1988年   2篇
  1986年   2篇
  1985年   4篇
  1984年   4篇
  1983年   5篇
  1982年   1篇
  1981年   1篇
  1979年   1篇
排序方式: 共有4996条查询结果,搜索用时 15 毫秒
1.
Monetary policy relies on managing the inflation expectations of the public in order to influence prices (inflation). Relying on the South African experience, we argue that most of the general public are exposed to the communication of the South African Reserve Bank (SARB) only via the media. This state of affairs is fairly typical around the globe. We explored the role and biases of the journalists in transmitting the SARB’s communications to the rationally inattentive general public. Our aim was to obtain insights about the factors that influence media articles that deal with monetary policy issues. Using interviews and qualitative content analysis, we explored the extent of the journalists’ knowledge about inflation and monetary policy, their views concerning the credibility of the SARB, the sources of information they use, and the constraints and incentives they face in writing their articles.  相似文献   
2.
We exploit an influential 1991 Delaware court ruling to examine simultaneously two types of conservatism that play important roles in resolving creditor–owner agency conflicts: contracting conservatism and reporting conservatism. The ruling expanded managerial fiduciary duties in favor of creditors for Delaware-incorporated firms in the vicinity of insolvency. In those firms, following the ruling, debt contracts are less likely to include conservative adjustments to accounting numbers used for covenant compliance (i.e., contracting conservatism decreases), while public financial reporting becomes more conservative (i.e., reporting conservatism increases). The decrease in contracting conservatism is concentrated in firms that exhibit a greater increase in reporting conservatism, suggesting that reporting conservatism is more cost-effective in resolving agency conflicts. In addition, the substitution effect is more pronounced in firms facing greater business uncertainty and firms with greater board independence.  相似文献   
3.
This study aims to examine the motives behind retailers’ post-entry expansion in foreign markets. Through case studies of eleven participating luxury fashion retailers in China, qualitative data was collected from twenty-two executive interviews. Although their initial market entry was driven by both reactive (push) and proactive (pull) factors, the motives behind their post-entry expansion have become predominantly proactive, especially long-term growth strategies, the ambition to extend their brands and retail formats to more cities, and the experiences gained in entry markets. The desire to optimize the retail store portfolio through multiple channel strategies have slowed down the expansions of physical stores.  相似文献   
4.
This study examined how entry‐level employees interacted with social media during three stages of organizational socialization. They navigated between four different media affordances (persistence, editability, visibility, and association) while experiencing them as both enabling and constraining in different socialization stages. Qualitative interview data analysis revealed during anticipatory socialization, job applicants realized visibility and persistence in relation to institutional and individualized socialization. During encounter, new employees managed personal and professional life boundaries carefully against the association and visibility affordances. Although some participants used both public and enterprise social media for obtaining job‐related information and understanding coworkers and company culture, during metamorphosis, most interviewees adopted passive information seeking strategies and experienced a paradoxical tension between the enabling and constraining affordances of social media. Findings are discussed with regards to employees’ exertion of agency in managing their professional impressions and coping with high levels of uncertainty and vulnerability during early stages of socialization.  相似文献   
5.
Luby变换(Luby Transform,LT)码作为信道编码应用于电力线通信(Power Line Communication,PLC),可实现电信号的可靠传输。度分布对LT码编译码性能的影响至关重要。为了得到更优的度分布,首先调整二进制指数分布(Binary Exponential Distribution,BED)中的度数比例,获得一种译码性能更优的改进的二进制指数分布(Improved BED,IBED)。然后,根据IBED在冗余度较小时译码成功率高,而冗余度增大后鲁棒孤子分布(Robust Soliton Distribution,RSD)的译码性能表现更佳的特点,通过求和归一化的方式将IBED与RSD两种度分布的优势进行有机结合,提出一种新型二进制鲁棒孤子分布(Binary RSD,BRSD)。仿真结果表明,与其他方法及传统的RSD相比,采用新度分布进行LT编码,可明显降低译码开销,并节约编译码耗时。将新型度分布应用于基于LT码的PLC系统中,能有效地抑制PLC信道中各种噪声对电信号的干扰,并提高通信效率。  相似文献   
6.
We comprehensively analyze the predictive power of several option-implied variables for monthly S&P 500 excess returns and realized variance. The correlation risk premium (CRP) and the variance risk premium (VRP) emerge as strong predictors of both excess returns and realized variance. This is true both in- and out-of-sample. Our results also reveal that statistical evidence of predictability does not necessarily lead to economic gains. However, a timing strategy based on the CRP leads to utility gains of more than 5.03% per annum. Forecast combinations provide stable forecasts for both excess returns and realized variance, and add economic value.  相似文献   
7.
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   
8.
This paper presents the case for and the evidence in favour of passive investment strategies and examines the major criticisms of the technique. I conclude that the evidence strongly supports passive investment management in all markets—small–capitalisation stocks as well as large–capitalisation equities, US markets as well as international markets, and bonds as well as stocks. Recent attacks on the efficient market hypothesis do not weaken the case for indexing.  相似文献   
9.
R.Q. Doeswijk 《De Economist》1997,145(4):573-598
The efficient markets hypothesis states that at any times security prices fully reflect all available information. Contrarian investment strategies do not recognize the efficiency of capital markets. They call for buying undervalued stocks, i.e. stocks with a low price relative to their fundamentals. The idea behind such a strategy is to take advantage of the extrapolation behaviour of naive investors. Using a fresh and extensive data set from the Dutch stock market, we found that these strategies yield an outperformance without a higher risk. Our results make it hard to maintain the efficient market hypothesis.  相似文献   
10.
本文综述了混合拉曼/掺饵光纤放大器(HFA)的工作原理,结构和特点,介绍了4类HFA基本结构及其实验结果,并通过介绍近年来各类HFA在密集波分复用(DWDM)系统中的应用表明了HFA在带宽,增益和噪声特性方面的优点。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号