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   3389篇
  免费   145篇
  国内免费   12篇
财政金融   1071篇
工业经济   92篇
计划管理   629篇
经济学   609篇
综合类   183篇
运输经济   26篇
旅游经济   51篇
贸易经济   437篇
农业经济   162篇
经济概况   286篇
  2024年   16篇
  2023年   67篇
  2022年   80篇
  2021年   134篇
  2020年   194篇
  2019年   146篇
  2018年   131篇
  2017年   172篇
  2016年   144篇
  2015年   116篇
  2014年   211篇
  2013年   399篇
  2012年   195篇
  2011年   248篇
  2010年   171篇
  2009年   166篇
  2008年   159篇
  2007年   151篇
  2006年   122篇
  2005年   99篇
  2004年   87篇
  2003年   57篇
  2002年   49篇
  2001年   54篇
  2000年   47篇
  1999年   39篇
  1998年   32篇
  1997年   15篇
  1996年   13篇
  1995年   12篇
  1994年   3篇
  1993年   5篇
  1992年   4篇
  1991年   5篇
  1989年   2篇
  1988年   1篇
排序方式: 共有3546条查询结果,搜索用时 15 毫秒
21.
We examine the presence or absence of asymmetric volatility in the exchange rates of Australian dollar (AUD), Euro (EUR), British pound (GBP) and Japanese yen (JPY), all against US dollar. Our investigation is based on a variant of the heterogeneous autoregressive realized volatility model, using daily realized variance and return series from 1996 to 2004. We find that a depreciation against USD leads to significantly greater volatility than an appreciation for AUD and GBP, whereas the opposite is true for JPY. Relative to volatility on days following a positive one-standard-deviation return, volatility on days following a negative one-standard-deviation return is higher by 6.6% for AUD, 6.1% for GBP, and 21.2% for JPY. The realized volatility of EUR appears to be symmetric. These results are robust to the removal of jump component from realized volatility and the sub-samplings defined by structural-changes. The asymmetry in AUD, GBP and JPY appears to be embedded in the continuous component of realized volatility rather than the jump component.  相似文献   
22.
The study examines the relative ability of various models to forecast daily stock index futures volatility. The forecasting models that are employed range from naïve models to the relatively complex ARCH-class models. It is found that among linear models of stock index futures volatility, the autoregressive model ranks first using the RMSE and MAPE criteria. We also examine three nonlinear models. These models are GARCH-M, EGARCH, and ESTAR. We find that nonlinear GARCH models dominate linear models utilizing the RMSE and the MAPE error statistics and EGARCH appears to be the best model for forecasting stock index futures price volatility.  相似文献   
23.
Initial margin requirements represent: (1) a cost impediment to the wealth constrained investor and (2) a potential way of mitigating excessive volatility. However, prior empirical research finds that margins are not an effective tool in reducing volatility. We consider the possibility that margins primarily affect certain stocks and investors. Specifically, we test whether margins affect individuals who, as a group, we believe to be the investors most affected when margin requirements change. Our initial empirical tests, however, do not support this contention.  相似文献   
24.
古老而先进的服装文明建设遭遇了浮躁而滞后的服装教育 ;博大精深的服装文化被简单而肤浅地诠释了。功利主义将服装教育引入了重重误区 ,服装教育的管理体制、院校布局、教育理念、层次划分、专业设置等 ,亟待规范。为此 ,本文提出了中国服装教育标本兼治的思路和一些对策。  相似文献   
25.
An extensive collection of continuous-time models of the short-term interest rate is evaluated over data sets that have appeared previously in the literature. The analysis, which uses the simulated maximum likelihood procedure proposed by Durham and Gallant (2002), provides new insights regarding several previously unresolved questions. For single factor models, I find that the volatility, not the drift, is the critical component in model specification. Allowing for additional flexibility beyond a constant term in the drift provides negligible benefit. While constant drift would appear to imply that the short rate is nonstationary, in fact, stationarity is volatility-induced. The simple constant elasticity of volatility model fits weekly observations of the three-month Treasury bill rate remarkably well but is easily rejected when compared with more flexible volatility specifications over daily data. The methodology of Durham and Gallant can also be used to estimate stochastic volatility models. While adding the latent volatility component provides a large improvement in the likelihood for the physical process, it does little to improve bond-pricing performance.  相似文献   
26.
Progressive stress accelerated life tests under finite mixture models   总被引:1,自引:0,他引:1  
In this paper, progressive stress accelerated life tests are considered when the lifetime of a product under use condition follows a finite mixture of distributions. The experiment is performed when each of the components in the mixture follows a general class of distributions which includes, among others, the Weibull, compound Weibull, power function, Gompertz and compound Gompertz distributions. It is assumed that the scale parameter of each component satisfies the inverse power low, the progressive stress is directly proportional to time and the cumulative exposure model for the effect of changing stress holds. Based on type-I censoring, the maximum likelihood estimates (MLEs) of the parameters under consideration are obtained. A special attention is paid to a mixture of two Rayleigh components. Simulation results are carried out to study the precision of the MLEs and to obtain confidence intervals for the parameters involved.  相似文献   
27.
刘丽莎  张莉 《基建优化》2007,28(4):89-91
车辆超载是一个普遍存在的问题,对道路路面的正常使用具有很大影响,是道路路面使用初期产生严重破坏的主要原因.结合深南路的路面修缮工程,分析重载交通柔性路面结构修缮所面临的实际问题.  相似文献   
28.
A semiparametric GARCH model for foreign exchange volatility   总被引:2,自引:0,他引:2  
A semiparametric extension of the GJR model (Glosten et al., 1993. Journal of Finance 48, 1779–1801) is proposed for the volatility of foreign exchange returns. Under reasonable assumptions, asymptotic normal distributions are established for the estimators of the model, corroborated by simulation results. When applied to the Deutsche Mark/US Dollar and the Deutsche Mark/British Pound daily returns data, the semiparametric volatility model outperforms the GJR model as well as the more commonly used GARCH(1,1) model in terms of goodness-of-fit, and forecasting, by correcting overgrowth in volatility.  相似文献   
29.
We investigate how economic policy uncertainty (EPU) and geopolitical risks (GPR) impact Bitcoin volatility with respect to factors related to type and nationality of uncertainty, investigated period, relationship horizon and extreme conditions. Applying ARDL model and quantile regression for monthly data from August 2010 to September 2021, we reveal that June 2014 corresponds to a key date that marks a reversal in the investigated relationship. Furthermore, we show that the relationship between uncertainty and bitcoin volatility changes according to different factors. US uncertainty has short run effects on Bitcoin volatility, while China’s uncertainty has rather long run effects. Moreover, Bitcoin volatility responds in the same manner to US EPU and GPR, while, it responds differently to China's EPU and GPR. In extreme quantiles, we find that Bitcoin hedges against US EPU and GPR. Further, Bitcoin hedges against either individual or joint effects of US uncertainty, but not both.  相似文献   
30.
权证在性质上也是一种期权,但并不是一种单纯的期权,定价要比普通期权复杂。我国在近十年后,重新推出了权证。在一系列假设条件下,利用Black—Scholes和二叉树模型,推导出权证定价公式。最后采用我国发行的权证及标的股票的收盘价格资料,计算了公司权益的波动率,从而利用已推导的公式对权证理论价值进行了实证分析。并同其实际市场价进行了比较,为权证的投资决策提供了参考依据。  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