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   3685篇
  免费   143篇
  国内免费   46篇
财政金融   185篇
工业经济   146篇
计划管理   1325篇
经济学   404篇
综合类   482篇
运输经济   78篇
旅游经济   64篇
贸易经济   580篇
农业经济   246篇
经济概况   364篇
  2024年   1篇
  2023年   48篇
  2022年   49篇
  2021年   75篇
  2020年   101篇
  2019年   70篇
  2018年   64篇
  2017年   78篇
  2016年   79篇
  2015年   133篇
  2014年   308篇
  2013年   275篇
  2012年   308篇
  2011年   432篇
  2010年   338篇
  2009年   208篇
  2008年   258篇
  2007年   206篇
  2006年   224篇
  2005年   150篇
  2004年   99篇
  2003年   95篇
  2002年   60篇
  2001年   66篇
  2000年   44篇
  1999年   23篇
  1998年   16篇
  1997年   18篇
  1996年   8篇
  1995年   6篇
  1994年   5篇
  1993年   5篇
  1992年   6篇
  1991年   9篇
  1989年   3篇
  1988年   1篇
  1987年   1篇
  1986年   2篇
  1985年   2篇
排序方式: 共有3874条查询结果,搜索用时 15 毫秒
1.
Advance selling is a marketing strategy commonly used by online retailers to increase sales by exploiting consumer valuation uncertainty. Recently, some online retailers have started to allow refunds on products sold in advance. On the one hand this reduces the net advance sales, but on the other hand it allows a higher advance sales price. This research is the first to explore the overall effect of allowing a refund on profits from advance sales, identifying conditions where advance selling with or without refunds (or no advance selling at all) is best. We analytically compare the profits of three advance selling strategies: none, without refund, and with refund. We show that selling in advance and allowing a refund is optimal for products with a relatively small profit margin and small strategic market size, and that the added profit can be considerable. Our results guide managers in selecting the right advance selling strategy. To facilitate this, we graphically display, based on the two dimensions of regular profit margin and strategic market size, under what conditions the different strategies are optimal.  相似文献   
2.
We investigate the impact of direct payments on agricultural commercialisation in Kosovo. Kosovo is one of the poorest countries in Europe but, with European assistance, provides substantial funds to support agriculture, made up of many small and often semi‐subsistence farms. Thus, the effect of this support is a central policy issue. Identifying the effect of direct payments on market participation faces endogeneity issues arising from the possible simultaneous determination of participation in support programmes and market participation. In order to achieve proper identification of the endogenous direct payments, we use a strategy of targeted identification search that employs several different methodological approaches. We find that direct payments for fruit and vegetables, and those for cereals and oilseeds have a positive effect on market participation. However, we cannot identify any definite effect of livestock payments.  相似文献   
3.
We study individually rational rules to be used to allot, among a group of agents, a perfectly divisible good that is freely available only in whole units. A rule is individually rational if, at each preference profile, each agent finds that her allotment is at least as good as any whole unit of the good. We study and characterize two individually rational and efficient families of rules, whenever agents' preferences are symmetric single-peaked on the set of possible allotments. Rules in the two families are in addition envy-free, but they differ on whether envy-freeness is considered on losses or on awards. Our main result states that (a) the family of constrained equal losses rules coincides with the class of all individually rational and efficient rules that satisfy justified envy-freeness on losses and (b) the family of constrained equal awards rules coincides with the class of all individually rational and efficient rules that satisfy envy-freeness on awards.  相似文献   
4.
This paper aimed to present an original approach for solving the aircraft stand allocation (SA) problem dynamically when due to operational disturbances, the planned allocation cannot be accomplished. The proposed Multiple-criteria Dynamic Stand Allocation (MDSA) method uses fuzzy logic to support decision-making under uncertainty. The MDSA method provides effective solutions in a short time, necessary for traffic management in case of delays, emergency, and untypical cases. It considers partially conflicting points of view of different airport users (airport managers, air traffic controllers, airlines, handling agents, and passengers) and may significantly support managers on the SA problem. The approach proposed can also be used for creating an initial SA plan for a considerable number of aircraft.  相似文献   
5.
We study the optimal execution problem with multiplicative price impact in algorithmic trading, when an agent holds an initial position of shares of a financial asset. The interselling decision times are modeled by the arrival times of a Poisson process. The criterion to be optimized consists in maximizing the expected net present value of the gains of the agent, and it is proved that an optimal strategy has a barrier form, depending only on the number of shares left and the level of the asset price.  相似文献   
6.
The estimation of the parameters of a continuous-time Markov chain from discrete-time observations, also known as the embedding problem for Markov chains, plays in particular an important role for the modeling of credit rating transitions. This missing data problem boils down to a latent variable setting and thus, maximum likelihood estimation is usually conducted using the expectation-maximization (EM) algorithm. We illustrate that the EM algorithm is likely to get stuck in local maxima of the likelihood function in this specific problem setting and adapt a stochastic approximation simulated annealing scheme (SASEM) as well as a genetic algorithm (GA) to combat this issue. Above that, our main contribution is to extend our method GA by a rejection sampling scheme, which allows one to derive stochastic monotone maximum likelihood estimates in order to obtain proper (non-crossing) multi-year probabilities of default. We advocate the use of this procedure as direct constrained optimization (of the likelihood function) will not be numerically stable due to the large number of side conditions. Furthermore, the monotonicity constraint enables one to combine structural knowledge of the ordinality of credit ratings with real-life data into a statistical estimator, which has a stabilizing effect on far off-diagonal generator matrix elements. We illustrate our methods by Standard and Poor’s credit rating data as well as a simulation study and benchmark our novel procedure against an already existing smoothing algorithm.  相似文献   
7.
姚惠芳 《现代食品》2021,(3):26-27,33
预包装食品标签作为展示产品质量重要内容之一,主要展示了食品生产者、质量指标、营养指标等信息,是消费者选购食品的主要参考依据。本文依据常用的国家标准及相关法律法规,对预包装食品标签常见问题及原因进行分析,并提出建议,为食品生产企业规范食品标签提供参考,也为食品安全监管部门日常监管提供一定的技术支持。  相似文献   
8.
This paper analyses the economic and financial repercussions of the 2020 COVID‐19 pandemic. It argues that the pandemic has inflicted serious injuries to the labor force but has not damaged the physical capital stock. Therefore, the resolution policies of this crisis ought to be carefully tailored to supporting structural adjustments to the labor market. The analysis asserts that the impact of the pandemic crisis is exacerbated by the identification gap between the unobserved and the officially reported cases of COVID‐19. The gap increases financial risks, including market‐, credit‐, default‐, and foreign exchange risks.  相似文献   
9.
The decisions a researcher makes at the model building stage are crucial for parameter identification. This paper contains a number of applied tips for solving identifiability problems and improving the strength of DSGE model parameter identification by fine-tuning the (1) choice of observables, (2) functional specifications, (3) model features and (4) choice of structural shocks. We offer a formal approach based on well-established diagnostics and indicators to uncover and address both theoretical (yes/no) identifiability issues and weak identification from a Bayesian perspective. The concepts are illustrated by two exemplary models that demonstrate the identification properties of different investment adjustment cost specifications and output-gap definitions. Our results provide theoretical support for the use of growth adjustment costs, investment-specific technology, and partial inflation indexation.  相似文献   
10.
Abstract

This study aimed to investigate the role that a professionalized context plays in shaping employee reactions to talent management decisions. We examined the mediating role of felt obligation in the relationship between talent ratings and organizational citizenship behavior. Further, the study tested whether professional identification moderates the relationship between talent ratings and felt obligation towards the organization. Five hundred and ninety-eight teachers that had recently received ratings of their talent status responded to a survey questionnaire. Felt obligation mediated the relationship between talent ratings and organizational citizenship behavior. Furthermore, professional identification moderated the relationship between ratings of potential and felt obligation in such a way that the relationship was strongest for the teachers expressing the lowest professional identification. At high levels of professional identification, the relationship was not significant. These results indicate that conventional talent management might be less effective for increasing favorable attitudes and behaviors among employees in highly professionalized contexts, such as the education sector.  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