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   63867篇
  免费   2113篇
  国内免费   1074篇
财政金融   5594篇
工业经济   2607篇
计划管理   12619篇
经济学   11707篇
综合类   12213篇
运输经济   385篇
旅游经济   1063篇
贸易经济   8431篇
农业经济   4255篇
经济概况   8178篇
信息产业经济   2篇
  2024年   171篇
  2023年   687篇
  2022年   881篇
  2021年   1287篇
  2020年   1617篇
  2019年   1157篇
  2018年   1102篇
  2017年   1215篇
  2016年   1249篇
  2015年   1491篇
  2014年   3598篇
  2013年   4359篇
  2012年   5011篇
  2011年   6347篇
  2010年   4719篇
  2009年   4294篇
  2008年   4900篇
  2007年   4731篇
  2006年   4728篇
  2005年   3455篇
  2004年   2423篇
  2003年   2009篇
  2002年   1321篇
  2001年   1158篇
  2000年   778篇
  1999年   379篇
  1998年   203篇
  1997年   212篇
  1996年   169篇
  1995年   101篇
  1994年   95篇
  1993年   87篇
  1992年   64篇
  1991年   52篇
  1990年   48篇
  1989年   31篇
  1988年   28篇
  1987年   14篇
  1986年   12篇
  1985年   186篇
  1984年   199篇
  1983年   140篇
  1982年   102篇
  1981年   61篇
  1980年   73篇
  1979年   47篇
  1978年   37篇
  1977年   23篇
  1975年   1篇
  1973年   1篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
This study evaluates a wide range of machine learning techniques such as deep learning, boosting, and support vector regression to predict the collection rate of more than 65,000 defaulted consumer credits from the telecommunications sector that were bought by a German third-party company. Weighted performance measures were defined based on the value of exposure at default for comparing collection rate models. The approach proposed in this paper is useful for a third-party company in managing the risk of a portfolio of defaulted credit that it purchases. The main finding is that one of the machine learning models we investigate, the deep learning model, performs significantly better out-of-sample than all other methods that can be used by an acquirer of defaulted credits based on weighted-performance measures. By using unweighted performance measures, deep learning and boosting perform similarly. Moreover, we find that using a training set with a larger proportion of the dataset does not improve prediction accuracy significantly when deep learning is used. The general conclusion is that deep learning is a potentially performance-enhancing tool for credit risk management.  相似文献   
42.
Prior literature indicates that quadratic models and the Black–Karasinski model are very promising for CDS pricing. This paper extends these models and the Black [J. Finance 1995, 50, 1371–1376] model for pricing sovereign CDS’s. For all 10 sovereigns in the sample quadratic models best fit CDS spreads in-sample, and a four factor quadratic model can account for the joint effects on CDS spreads of default risk, default loss risk and liquidity risk with no restriction to factors correlation. Liquidity risk appears to affect sovereign CDS spreads. However, quadratic models tend to over-fit some CDS maturities at the expense of other maturities, while the BK model is particularly immune from this tendency. The Black model seems preferable because its out-of-sample performance in the time series dimension is the best.  相似文献   
43.
We study the cost of shocks, that is, jump risk, with respect to reserve management when the reserve process is formulated as a drift‐switching jump diffusion with a reflecting barrier at 0. Inspired by the Brownian drift switching model, our model results in a more realistic dynamic behavior of international reserves than the buffer stock model. The new model can capture both the jump behavior in reserve dynamics and the leptokurtic feature of the increment distribution which has a higher peak and two asymmetric heavier tails than the normal distribution. Through the selection of an initial distribution that reflects certain steady state behaviors, the reserve process becomes a regenerative process. This selection enables us to derive a closed‐form expression for the total expected discounted cost of managing reserves, thus helping us to numerically find management strategies that minimize costs. The numerical results show that shocks at the reserve level have a significant effect on reserve management strategies and that model misspecification can result in nonnegligible additional costs.  相似文献   
44.
We model market integration in the Middle East and Africa by analyzing price dispersion and testing the law of one price (LOP) on highly-comparable actual local retail prices of 135 goods and services across 23 countries in the region over the period of 1990–2016. Second-generation panel estimators are applied to four price benchmarks: Regional average, South Africa, China, and US prices. Cross-regional price dispersion diminishes considerably over time up to 2008, particularly for non-tradeables around China price. The test of LOP indicates the percentage of convergent prices is highest in China price benchmark, followed by US, South Africa, and regional average benchmarks. Direct estimation of the convergence speed confirms this order. Overall, the results show evidence of increasing market integration in Middle East and Africa but it appears to be driven by global forces and, especially, the rise of China as a new economic power. The results show that some emerging market economies, such as China, can step up and promote integration while traditional economic powerhouses, such as the USA and UK, disengage from international economic relations.  相似文献   
45.
随着我国社会发展的不断推进与创新,对于执政基础的巩固、在最大限度内保证党的执政能力等均成为使基层党建可以获得良好效果的主要手段,并且使工作在不断的实践探索中获得更好的成效。但是,以党建引领基层社会治理的过程仍然存在众多问题,其中包括形式化严重以及做表面功夫等。因此,如何在新时代的背景下,通过党的全面领导将党与群众紧密地联系在一起,从而确保党建工作可以在基层发挥更强的社会治理职能,已成为基层社会治理模式探索并创新的主要内容。  相似文献   
46.
The authors propose and empirically test a causal model to understand how the availability of fair-trade information and consumer knowledge about this issue affect consumers’ attitudes and intentions toward fair-trade products. The model is built upon the attitude-behavior paradigm and the premises of agency theory. It is tested through structural equation modeling with a sample of 292 Spanish consumers. The findings are that consumers do not have good knowledge about fair trade and that this is significantly determined by the lack of information about this in the market. It is also observed that consumers’ perceptions about the availability of fair-trade information have negative effects on their concern about this issue and that such information as is available is not effective in reducing consumer skepticism. The research represents an extension of previous fair-trade literature because the role of information and communication in improving consumer attitudes and buying intentions has rarely been explored in the case of ethical products.  相似文献   
47.
Despite the heightened popularity of entrepreneurship education, there remain open questions regarding best practices in co-curricular programs. Using the theory of planned behavior, the authors examine how students’ intention is shaped to increase the likelihood of participation in entrepreneurship co-curricular programs. To the best of the authors’ knowledge, this study is the first to examine the relation between entrepreneurial identity and entrepreneurial intention theory. They find the popular personality trait, openness, is related to ambition, which reveals the interaction between personal elements (personality/identity) and contextual elements (aspirations to success/intention), a novel finding in the literature. This further illustrates the interconnectedness between the theory of planned behavior and the entrepreneurial event model  相似文献   
48.
Following the approach of interpolation, this paper proposes the multiple exponential decay model to fit yield curves for both the U.S. TIPS market and the conventional Treasury security market. Several estimation methods, including the unconstrained/constrained nonlinear minimization, quadratic programming, and the iterative linear least squares, are applied to estimate the unknown parameters according to different curve‐fitting purposes. Comparisons between the proposed model and the alternatives show that the multiple exponential decay successfully (1) adapts to a variety of shapes associated with yield curves, (2) (partially) keeps in line with the economic interpretations of Nelson–Siegel summarized by Diebold and Li ( 2006 ), and (3) dominates the competing models in curve‐fitting performance measured by mean fitted‐price errors over the sample period. In addition, the exact specification of a nonparametric interpolation model is pinned down by applying three statistical tools, which enable us to jointly take into account validity, optimality, and parsimoniousness of the proposed model.  相似文献   
49.
This article uses a multi-country global general equilibrium (GE) model to numerically simulate the effects of possible China–US trade wars. We introduce an endogenous trade imbalance structure with trade cost into the model which helps to explore both tariff and non-tariff trade war effects. Our simulation results show that China will be significantly hurt by the China–US trade war, but negative impacts are affordable. The US can gain under unilateral sanction measures to China, but will lose if China takes retaliation measures. Comparing the effects under mutual trade war, China will lose more than the US. Introducing non-tariff barrier trade wars will intensify the negative effects, and comparatively negative effects to China are larger than to the US. Mexico’s involvement in trade war with the US will strengthen the negative effects and comparatively hurt the US more. Under non-cooperative and cooperative Nash bargaining equilibrium, the US can gain more than China in trade war negotiation, which means the US has stronger bargaining power than China. Additionally, trade wars between China and the US will hurt most countries and the world especially in GDP and manufacturing employment, but benefit their welfare and trade.  相似文献   
50.
隔代抚育会对延迟退休年龄政策在促进劳动力供给上产生挤出效应。为了对此进行验证,本文在工资收入随机性的假定及延迟退休5年的情景下,模拟了面临孙辈照护需求的女性临近退休者提前退休所产生的福利变化。进一步,本文采用CHIP和CHARLS的微观调查数据,对不同群组的收入增长率和收入风险进行了估计,继而分析了当面临孙辈照护需求时这些收入特征对退休决策者制度退休和退休后劳动参与抉择产生的影响。总体上,在延迟退休年龄政策下,隔代抚育将对女性劳动力供给产生挤出效应。当面临孙辈照护需求时,女性临近退休者的制度退休抉择主要受自身收入增长率和收入风险的影响,收入增长率越低,或收入风险越高,她们提前退休的意愿就越强烈;制度退休后的劳动参与则更多地受子女收入增长率的影响,子女收入增长率越高,劳动参与的概率越低。  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