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   1368篇
  免费   394篇
  国内免费   3篇
财政金融   48篇
工业经济   133篇
计划管理   456篇
经济学   58篇
综合类   75篇
运输经济   10篇
旅游经济   2篇
贸易经济   848篇
农业经济   83篇
经济概况   52篇
  2024年   5篇
  2023年   21篇
  2022年   50篇
  2021年   82篇
  2020年   76篇
  2019年   62篇
  2018年   65篇
  2017年   53篇
  2016年   68篇
  2015年   97篇
  2014年   141篇
  2013年   137篇
  2012年   148篇
  2011年   162篇
  2010年   113篇
  2009年   62篇
  2008年   112篇
  2007年   65篇
  2006年   64篇
  2005年   45篇
  2004年   49篇
  2003年   29篇
  2002年   23篇
  2001年   16篇
  2000年   2篇
  1999年   6篇
  1998年   2篇
  1997年   1篇
  1996年   2篇
  1995年   1篇
  1992年   2篇
  1991年   1篇
  1989年   2篇
  1987年   1篇
排序方式: 共有1765条查询结果,搜索用时 15 毫秒
1.
This theoretical perspective paper interprets (un)known-(un)known risk quadrants as being formed from both abstract and concrete risk knowledge. It shows that these quadrants are useful for categorising risk forecasting challenges against the levels of abstract and concrete risk knowledge that are typically available, as well as for measuring perceived levels of abstract and concrete risk knowledge available for forecasting in psychometric research. Drawing on cybersecurity risk examples, a case is made for refocusing risk management forecasting efforts towards changing unknown-unknowns into known-knowns. We propose that this be achieved by developing the ‘boosted risk radar’ as organisational practice, where suitably ‘risk intelligent’ managers gather ‘risk intelligence information’, such that the ‘risk intelligent organisation’ can purposefully co-develop both abstract and concrete risk forecasting knowledge. We also illustrate what this can entail in simple practical terms within organisations.  相似文献   
2.
The paper presents a new methodology, based on tensor decomposition, to map dynamic trade networks and to assess its strength in forecasting economic fluctuations at different periods of time in Asia. Using the monthly merchandise import and export data across 33 Asian economies, together with the US, EU and UK, we detect the community structure of the evolving network and we identify clusters and central nodes inside each of them. Our findings show that data are well represented by two communities, in which People's Republic of China and Japan play the major role. We then analyze the synchronisation between GDP growth and trade. Furthermore we apply our model to the prediction of economic fluctuations. Our findings show that the model leads to an increase in predictive accuracy, as higher order interactions between countries are taken into account.  相似文献   
3.
Determination of Discrete Spectrum in a Random Field   总被引:1,自引:0,他引:1  
We consider a two dimensional frequency model in a random field, which can be used to model textures and also has wide applications in Statistical Signal Processing. First we consider the usual least squares estimators and obtain the consistency and the asymptotic distribution of the least squares estimators. Next we consider an estimator, which can be obtained by maximizing the periodogram function. It is observed that the least squares estimators and the estimators obtained by maximizing the periodogram function are asymptotically equivalent. Some numerical experiments are performed to see how the results work for finite samples. We apply our results on simulated textures to observe how the different estimators perform in estimating the true textures from a noisy data.  相似文献   
4.
This paper investigates the dividend signaling hypothesis, described here as the relationship between dividend changes and future earnings performance. We find that managers pursue different patterns in UK from that in US when making dividend policy. A positive and significant association between dividend changes and the growth of future earnings is observed in the immediately following year after dividend announced There isn't significant link in the longer future. These phenomena are caused by managers' near-eyesight in UK market. In addition, an interesting finding is that dividend decreases have larger negative influence on earnings growth than positive impact on earnings prospects of dividend increases. This is consistent with the infrequent occurrence of dividend reduction.  相似文献   
5.
本文介绍了直接数字频率合成(DDS)芯片AD9852与可编程门阵列(FPGA)相结合采用数字方法实现中频线性相位调制(PM)及试验结果。  相似文献   
6.
介绍了小型化、通用化和实时信号处理要求下,雷达接收机的通用数据采集处理硬件平台。采用Xilinx公司最新平台级FPGA产品Spartan-3系列芯片构建平台,并实现其中的FFT于模块。试验表明,处理精度和速度都满足要求,为该方案的可行性和后续模块的实现提供了依据。  相似文献   
7.
Hall and Miles (1990) suggest an approach of estimating default probabilities of banks using stock market information, and in this paper we apply an aggregated version of their approach to banking sectors around the world in both developed and emerging economies. We study the market’s assessment of the probability of systemic banking crises world wide over the last decade, including the Asian crisis 1997–1998. In addition, we investigate whether there is a relationship between the failure probability and institutional features of the actual banking sector. The quality of governance and the degree of law and order in a country is found to be significantly negatively related to the market based failure probabilities as is an explicit deposit insurance during periods of crisis.  相似文献   
8.
多功能信号发生器的设计   总被引:1,自引:0,他引:1  
以MAX038集成芯片为核心,采用MCU微处理器控制程控继电器和数字电位器,设计了多功能信号发生器。能够输出方波、正弦波、三角波和AM信号,并能实现频段选择和频段内频率微调。  相似文献   
9.
在多分辨率分析的基础上,采用二进正交小波变换对电力系统暂态信号进行了分析.将信号分解成许多细节部分和平滑部分(分别是信号的高频部分和细节部分),通过分析信号在各个尺度下的细节部分,从而可以对暂态信号的时域和频域进行定位.实验结果证实了方法的有效性.  相似文献   
10.
本文在了解上海商学院图文信息楼监控系统的基础上,结合DSP结构及功能提出了基于DSP 的视频采集系统的构想,并阐述在数字化技术飞速发展的今天,网络数字监控将会得到更好的升级与管理。  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