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   11946篇
  免费   365篇
财政金融   2385篇
工业经济   950篇
计划管理   2066篇
经济学   2598篇
综合类   136篇
运输经济   126篇
旅游经济   225篇
贸易经济   2088篇
农业经济   514篇
经济概况   1191篇
邮电经济   32篇
  2023年   53篇
  2021年   81篇
  2020年   167篇
  2019年   204篇
  2018年   257篇
  2017年   269篇
  2016年   272篇
  2015年   199篇
  2014年   287篇
  2013年   1375篇
  2012年   387篇
  2011年   447篇
  2010年   403篇
  2009年   469篇
  2008年   391篇
  2007年   374篇
  2006年   336篇
  2005年   332篇
  2004年   306篇
  2003年   330篇
  2002年   298篇
  2001年   267篇
  2000年   277篇
  1999年   270篇
  1998年   266篇
  1997年   242篇
  1996年   232篇
  1995年   210篇
  1994年   195篇
  1993年   187篇
  1992年   162篇
  1991年   164篇
  1990年   155篇
  1989年   126篇
  1988年   128篇
  1987年   109篇
  1986年   128篇
  1985年   189篇
  1984年   194篇
  1983年   163篇
  1982年   146篇
  1981年   135篇
  1980年   148篇
  1979年   130篇
  1978年   123篇
  1977年   106篇
  1976年   109篇
  1975年   91篇
  1974年   83篇
  1973年   72篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
The main objective of this paper it to model the dynamic relationship between global averaged measures of Total Radiative Forcing (RTF) and surface temperature, measured by the Global Temperature Anomaly (GTA), and then use this model to forecast the GTA. The analysis utilizes the Data-Based Mechanistic (DBM) approach to the modelling and forecasting where, in this application, the unobserved component model includes a novel hybrid Box-Jenkins stochastic model in which the relationship between RTF and GTA is based on a continuous time transfer function (differential equation) model. This model then provides the basis for short term, inter-annual to decadal, forecasting of the GTA, using a transfer function form of the Kalman Filter, which produces a good prediction of the ‘pause’ or ‘levelling’ in the temperature rise over the period 2000 to 2011. This derives in part from the effects of a quasi-periodic component that is modelled and forecast by a Dynamic Harmonic Regression (DHR) relationship and is shown to be correlated with the Atlantic Multidecadal Oscillation (AMO) index.  相似文献   
3.
4.
It is a wide-held assumption that professional development and change within purchasing and supply management (PSM) organisations can be explained and guided by a maturity model. In this paper the guidance which the maturity model concept offers to understand a PSM organisation's performance is assessed. The methodology is based on the outcomes of a literature review of PSM maturity models, development of an organisational change framework and the learning from three qualitative case studies. An alternative understanding of the development of the PSM organisation is offered through an organisational change framework, composing 1) movement transitions, 2) scalability of change, 3) acceptability of change, and 4) the substantive element of change. The research found that extant PSM maturity models are too rigid for PSM managers to apply, and although maturity models are commonly accepted in PSM literature, in practice, they may produce the opposite effect of what is promised. The PSM maturity models suggest that their application will lead to increased status and influence of PSM within the organisation; expectations that may not be met. PSM organisations’ change processes are subjected to a range of situational and contextual power relations which must be considered in order to advance the specific PSM organisation roles and responsibilities.  相似文献   
5.
China’s reform on central–local fiscal reform has slowed down in recent years. The appointment of a new finance minister experienced in local government affairs is expected to renew the reform affirmed by the Chinese Communist Party (CCP) congress in late 2017. China has unprecedentedly identified a comprehensive list of 81 national basic public services as entitlements. Eighteen of them are subject to national and local standards, and co-financed by central and local governments. A new cost-sharing method for 10 of these services classifies sub-national jurisdictions into five tiers, in which the central government’s share declines from 80% to 10%. These measures, effective in 2019, aim at creating a ‘harmonious and moderately prosperous society’.  相似文献   
6.
Mahoney  James  Acosta  Laura 《Quality and Quantity》2022,56(4):1889-1911
Quality & Quantity - This article discusses a regularity theory of causality (RTC) for the social sciences. With RTC, causality is a relationship between X and Y characterized by three...  相似文献   
7.
The general consensus in the volatility forecasting literature is that high-frequency volatility models outperform low-frequency volatility models. However, such a conclusion is reached when low-frequency volatility models are estimated from daily returns. Instead, we study this question considering daily, low-frequency volatility estimators based on open, high, low, and close daily prices. Our data sample consists of 18 stock market indices. We find that high-frequency volatility models tend to outperform low-frequency volatility models only for short-term forecasts. As the forecast horizon increases (up to one month), the difference in forecast accuracy becomes statistically indistinguishable for most market indices. To evaluate the practical implications of our results, we study a simple asset allocation problem. The results reveal that asset allocation based on high-frequency volatility model forecasts does not outperform asset allocation based on low-frequency volatility model forecasts.  相似文献   
8.
Our purpose is to explore the concept of “sustainability” when understood from a performative perspective, i.e. as a concept that is filled with meaning across time. Drawing on a 10 year-long study of the digital footprint of Stockholm Royal Seaport, claimed to be northern Europe's largest sustainable urban development district, we show that “sustainability” emerged as the project became associated with particular places, projects, histories, and technologies. This means that “sustainability” was local in that it was situated in the particular spatial context of the project; temporal in that it was situated in a particular time; and political in that it expressed particular values and perspectives. The study contributes to explaining why “sustainability” remains—and always will remain—a contested concept, which is why sustainability transitions are complex. Consequently, we suggest that the transition towards sustainability always involves the transition of sustainability, something that needs to be acknowledged in order for a transition to actually become sustainable.  相似文献   
9.
Both soft, noncontractible, and hard, contractible, information are informative about managerial ability and future firm performance. If a manager's future compensation depends on expectations of ability or future performance, then the manager has implicit incentives to affect the information. We examine the real incentive effects of soft information in a dynamic agency with limited commitment. When long-term contracts are renegotiated, the rewards for future performance inherent in long-term contracts allow the principal partial control over the implicit incentives. This is because the soft information affects the basis for contract renegotiation. With short-term contracts, the principal has no control over the basis for contract negotiation, and thus long-term contracts generally dominate short-term contracts. With long-term contracts, the principal's control over implicit incentives is characterized in terms of effective contracting on an implicit aggregation of the soft information that arises from predicting (forming expectations of) future performance. We provide sufficient conditions for soft information to have no real incentive effects. In general, implicit incentives not controllable by the principal include fixed effects, such as career concerns driven by labor markets external to the agency. When controllable incentives span the fixed effects of career concerns, the latter have no real effects with regard to total managerial incentives—they would optimally be the same with or without career concerns. Our analysis suggests empirical tests for estimating career concerns that should explicitly incorporate noncontractible information.  相似文献   
10.
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