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   574篇
  免费   16篇
  国内免费   5篇
财政金融   47篇
工业经济   12篇
计划管理   136篇
经济学   158篇
综合类   97篇
旅游经济   2篇
贸易经济   65篇
农业经济   21篇
经济概况   57篇
  2023年   4篇
  2022年   1篇
  2021年   4篇
  2020年   10篇
  2019年   12篇
  2018年   6篇
  2017年   10篇
  2016年   11篇
  2015年   8篇
  2014年   50篇
  2013年   40篇
  2012年   42篇
  2011年   60篇
  2010年   37篇
  2009年   41篇
  2008年   36篇
  2007年   34篇
  2006年   36篇
  2005年   32篇
  2004年   23篇
  2003年   22篇
  2002年   24篇
  2001年   8篇
  2000年   10篇
  1999年   8篇
  1998年   6篇
  1997年   3篇
  1996年   5篇
  1995年   2篇
  1994年   2篇
  1993年   2篇
  1992年   2篇
  1989年   1篇
  1987年   1篇
  1985年   1篇
  1982年   1篇
排序方式: 共有595条查询结果,搜索用时 62 毫秒
1.
This paper reviews some recent blockchain‐based applications for information capture, distribution and preservation. As part of that review, this paper examines two key concerns with current blockchain designs for accounting and supply chain transactions: data independence and multiple semantic models for the same information distribution problem. Blockchain applications typically integrate database, application and presentation tiers all in the same ledger. This results in a general inability to query information in the ledger and other concerns. Further, since most applications appear to be private blockchain applications, there is a concern of agents needing to accommodate multiple blockchains depending on who their trading partners are and what they request. Finally, this paper uses a distributed database to design a ‘blockchain‐like’ system for virtual organizations.  相似文献   
2.
We give an example of a subspace K of     such that     , where     denotes the closure with respect to convergence in probablity. On the other hand, the cone   C ≔ K − L +  is dense in   L   with respect to the weak-star topology  σ( L , L 1)  . This example answers a question raised by I. Evstigneev. The topic is motivated by the relation of the notion of no arbitrage and the existence of martingale measures in Mathematical Finance.  相似文献   
3.
We introduce a new method for proving large-deviation principles (LDPs). This method amounts to "mixing" a collection of LDPs with a sequence of probability measures that obeys itself an LDP. As an illustration, we construct from empirical measures a sequence of capacity-valued maps that can be considered as an indexed collection of LDPs. The index 1 coincides with Sanov's theorem. By taking a Poisson mixture we establish a new connection with Cramér's theorem.  相似文献   
4.
5.
This paper extends the mean-variance analysis and the two-fund separation theorem to a market with some constraints, such as, the incompleteness, prohibition of short-selling, and partial information, with stochastic interest rate, and with stochastic volatility for risky assets. By maximizing a quadratic utility of terminal wealth, we show that the efficient frontier for the problem is a straight line in the mean-standard-deviation diagram. The quadratic utility function exhibits mean-variance efficiency. Our results apply to portfolios of claims in a single period, multiperiod, and continuous time.  相似文献   
6.
对于密绕载流无限长螺线管,管外的磁场是否严格为零与管外磁场和管内磁场相比是否可以忽略不计,这是两个完全不同的问题。  相似文献   
7.
张爱群 《乡镇经济》2008,24(6):120-122
文章从实际出发,描述了目前我国农村民间金融的现状。从内生金融理论的角度分析了我国民间金融存在问题的原因。最后文章对我国农村民间金融的发展提出相应的政策建议。  相似文献   
8.
Conditional probability distributions seem to have a bad reputation when it comes to rigorous treatment of conditioning. Technical arguments are published as manipulations of Radon–Nikodym derivatives, although we all secretly perform heuristic calculations using elementary definitions of conditional probabilities. In print, measurability and averaging properties substitute for intuitive ideas about random variables behaving like constants given particular conditioning information.
One way to engage in rigorous, guilt-free manipulation of conditional distributions is to treat them as disintegrating measures—families of probability measures concentrating on the level sets of a conditioning statistic. In this paper we present a little theory and a range of examples—from EM algorithms and the Neyman factorization, through Bayes theory and marginalization paradoxes—to suggest that disintegrations have both intuitive appeal and the rigor needed for many problems in mathematical statistics.  相似文献   
9.
Probability theory in fuzzy sample spaces   总被引:2,自引:0,他引:2  
This paper tries to develop a neat and comprehensive probability theory for sample spaces where the events are fuzzy subsets of The investigations are focussed on the discussion how to equip those sample spaces with suitable -algebras and metrics. In the end we can point out a unified concept of random elements in the sample spaces under consideration which is linked with compatible metrics to express random errors. The result is supported by presenting a strong law of large numbers, a central limit theorem and a Glivenko-Cantelli theorem for these kinds of random elements, formulated simultaneously w.r.t. the selected metrics. As a by-product the line of reasoning, which is followed within the paper, enables us to generalize as well as to bring together already known results and concepts from literature.Acknowledgement. The author would like to thank the participants of the 23rd Linz Seminar on Fuzzy Set Theory for the intensive discussion of the paper. Especially he is indebted to Professors Diamond and Höhle whose remarks have helped to get deeper insights into the subject. Additionally, the author is grateful to one anonymous referee for careful reading and valuable proposals which have led to an improvement of the first draft.This paper was presented at the 23rd Linz Seminar on Fuzzy Set Theory, Linz, Austria, February 5–9, 2002.  相似文献   
10.
重心定理在进度控制中的运用   总被引:1,自引:0,他引:1  
该文主要讲述重心定理的含义以及在进度控制中如何运用它来解决两个平行工序顺序化的问题,并用一个例子说明其步骤,最后给出三条结论。  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