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   6905篇
  免费   358篇
  国内免费   123篇
财政金融   481篇
工业经济   348篇
计划管理   2207篇
经济学   1125篇
综合类   954篇
运输经济   129篇
旅游经济   55篇
贸易经济   766篇
农业经济   613篇
经济概况   707篇
信息产业经济   1篇
  2024年   6篇
  2023年   92篇
  2022年   108篇
  2021年   160篇
  2020年   213篇
  2019年   135篇
  2018年   106篇
  2017年   145篇
  2016年   186篇
  2015年   223篇
  2014年   518篇
  2013年   514篇
  2012年   566篇
  2011年   703篇
  2010年   539篇
  2009年   443篇
  2008年   538篇
  2007年   513篇
  2006年   442篇
  2005年   299篇
  2004年   220篇
  2003年   178篇
  2002年   136篇
  2001年   96篇
  2000年   87篇
  1999年   41篇
  1998年   35篇
  1997年   26篇
  1996年   30篇
  1995年   14篇
  1994年   12篇
  1993年   8篇
  1992年   9篇
  1991年   16篇
  1990年   4篇
  1989年   6篇
  1988年   4篇
  1987年   5篇
  1986年   5篇
  1985年   1篇
  1984年   2篇
  1983年   1篇
  1981年   1篇
排序方式: 共有7386条查询结果,搜索用时 13 毫秒
1.
We study a tug-of-war game between two players using the lottery contest success function (CSF) and a quadratic cost (of effort) function. We construct a pure strategy symmetric Markov perfect equilibrium of this game, show that it is unique, and provide closed-form solutions for equilibrium strategies and values. In stark contrast to a model of tug-of-war with an all-pay auction CSF, players exert positive efforts until the very last battle in this equilibrium. We deliver a set of empirically appealing results on effort dynamics.  相似文献   
2.
工程总承包模式以设计与施工的高度融合,日益在建筑业受到青睐。但由于政府投资项目中存在有关结余资金上缴国库等规定,容易导致政府投资工程总承包项目下设计优化产生的成果是进行分成或作为结余资金上缴界定不清。鉴于此,本文通过政策文件,并结合政府投资项目特点,分析政府投资工程总承包项目设计优化的情形认定以及在不同结算依据和合同计价方式下设计优化收益归属的界定,为有效激励总承包单位积极进行设计优化奠定基础。  相似文献   
3.
从航班计划优化的不同时间阶段分析,可以将航班计划优化分为航班计划静态编排优化、基于航班延误预测的航班计划动态反馈优化和基于机场协同决策(A-CDM)的航班计划动态调整角度三类;进而从航班时刻、机型指派、航班频率等编制环节分析了航班计划静态编排优化;随后利用延误波及预测与数据挖掘预测的优化方法分析了基于航班延误预测的航班计划动态反馈优化的相关研究。最后,根据航班计划优化复杂性分析,给出了航班计划优化的发展趋势和未来研究方向。  相似文献   
4.
Using a novel data set for the U.S. states, this paper examines whether household debt and the protracted debt deleveraging help explain the dismal performance of U.S. consumption since 2007 in the aftermath of the housing bubble. By separating the concepts of deleveraging and debt overhang—a flow and a stock effect—we find that excessive indebtedness exerted a meaningful drag on consumption over and beyond wealth and income effects. The overall effect, however, is modest—‐around one sixth of the slowdown in consumption between 2000–06 and 2007–12—and mostly driven by states with particularly large imbalances in their household sector. This might be indicative of non‐linearities, whereby indebtedness begins to bite only when misalignments from sustainable debt dynamics become excessive.  相似文献   
5.
This paper discusses the specifics of forecasting using factor-augmented predictive regressions under general loss functions. In line with the literature, we employ principal component analysis to extract factors from the set of predictors. In addition, we also extract information on the volatility of the series to be predicted, since the volatility is forecast-relevant under non-quadratic loss functions. We ensure asymptotic unbiasedness of the forecasts under the relevant loss by estimating the predictive regression through the minimization of the in-sample average loss. Finally, we select the most promising predictors for the series to be forecast by employing an information criterion that is tailored to the relevant loss. Using a large monthly data set for the US economy, we assess the proposed adjustments in a pseudo out-of-sample forecasting exercise for various variables. As expected, the use of estimation under the relevant loss is found to be effective. Using an additional volatility proxy as the predictor and conducting model selection that is tailored to the relevant loss function enhances the forecast performance significantly.  相似文献   
6.
提出了一种由单形规范线性分段(SCPWL)函数与记忆多项式级联的数字预失真器,并给出了复数域两步最小二乘参数辨识算法。不同于以往一种预失真器适用一种功放模型的情况,所提的预失真算法利用SCPWL函数的分段特性以及记忆多项式的非线性记忆特性,在完成参数辨识的同时自动地调整结构,可适用于传统以及强非线性新型功放模型的线性化补偿。将所提预失真器分别应用于传统记忆多项式、两箱模型以及新型包络跟踪功放。经过计算机仿真,功放输出的幅频特性和频谱曲线表明所提预失真器能够有效地补偿多种功放的非线性特性。算法仿真比较结果也表明,针对包络跟踪功放,所提复数两步最小二乘算法的邻道泄漏比(ACLR)可改善约35 dB,性能优于最小均方(LMS)类算法约30 dB。  相似文献   
7.
The Prebisch–Singer hypothesis in economics asserts that over time the relative price of primary goods relative to manufactured goods should experience a downward trend. To test the hypothesis, we must first establish the unit root properties of the relative price term and then regress the stationary series on a trend term. We use the quantile unit root test which allows for both smooth unknown numbers and the form of breaks in the trend function through a Fourier function to show that the relative price of 23 out of 24 primary goods is stationary. However, the Prebisch–Singer hypothesis is supported only in half of the primary commodities.  相似文献   
8.
The role of money in the design and conduct of monetary policy has reemerged as an important issue in both advanced and developing economies, especially since the 2007 global financial crisis. A growing body of recent literature suggests that the causal relationship between money supply growth and inflation remains intact across countries and over time and that this relation is not conditional on the stability of the money‐demand function or whether money is endogenous or exogenous. Moreover, critical for a rule‐based monetary policy is the presence of a long‐run stable money‐demand function, rather than a short‐run money‐demand model that may exhibit instability for many reasons, including problems with estimating a money‐demand model with high‐frequency data. Provided that a stable money‐demand function exists, it could be useful to establish long‐run equilibrium relations among money, output, prices, and exchange rates, as the classical monetary theory suggests. Within this analytical framework, this paper addresses the question of whether money has any role in the conduct of monetary policy in Australia. The conventional wisdom is that the money‐demand function in Australia has been unstable since the mid‐1980s due to financial deregulation and reforms; this led to a change in the strategy of monetary policy for price stability in the form of inflation targeting that ignores money insofar as inflation and its control are concerned. This paper reports empirical findings for Australia, obtained from a longer quarterly data series over the period 1960Q1–2015Q1, which suggest that instability in the narrow‐money‐demand function in Australia was primarily due to the exclusion of variables which have become important in the deregulated environment since the 1980s. These findings are confirmed by an expanded form of the narrow‐money‐demand function that was found stable over the past two decades, although it experienced multiple structural breaks over the study period. The paper draws the conclusion that abandoning the monetary aggregate as an instrument of monetary policy in Australia, under a rule‐based monetary policy such as inflation targeting, cannot be justified by instability in the money‐demand function or even by lack of a causal link between money supply growth and inflation.  相似文献   
9.
以内生增长理论为基础,运用巴罗的财政支出自然效率条件和改进的柯布-道格拉斯生产函数分别对中国城镇职工基本养老保险和城乡居民基本养老保险的最优财政支出规模进行测算,发现中国城镇职工基本养老保险和城乡居民基本养老保险的最优财政支出规模分别为2.33%和0.81%,目前两项养老保险的财政支出皆已超过了最优财政支出规模。为缓解养老保险的财政补贴压力,保证养老保险制度的良性运行,建议落实划转国有资本充实全国社会保障基金政策,实施基础养老金全国统筹,激发城镇职工和城乡居民缴费的积极性。  相似文献   
10.
设计认知无线网络路由算法时,需要兼顾主用户保护与路由性能两个方面。为了提高认知无线网络中次用户之间路由的端到端性能,提出了基于无线电环境地图的路由优化机制,该机制中无线电环境地图能够为次用户提供主用户保护有关的无线电环境数据。首先,无线电环境地图根据次用户的数据请求将各授权频段的可用概率与功率控制相关信息反馈到该次用户;其次,次用户可以计算出与上一跳次用户之间的链路稳定性以及传输时延;最后,目的次用户通过计算每条路由的端到端吞吐量的期望值,然后选取期望值最大的一条路由。仿真结果表明,该路由机制在平均分组投递率、平均端到端吞吐量、平均端到端时延方面均优于对比路由算法。  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