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   684篇
  免费   30篇
财政金融   133篇
工业经济   49篇
计划管理   112篇
经济学   152篇
综合类   14篇
运输经济   10篇
旅游经济   30篇
贸易经济   130篇
农业经济   31篇
经济概况   49篇
邮电经济   4篇
  2023年   4篇
  2022年   6篇
  2021年   9篇
  2020年   16篇
  2019年   18篇
  2018年   25篇
  2017年   24篇
  2016年   23篇
  2015年   18篇
  2014年   29篇
  2013年   83篇
  2012年   30篇
  2011年   35篇
  2010年   27篇
  2009年   32篇
  2008年   25篇
  2007年   24篇
  2006年   16篇
  2005年   10篇
  2004年   17篇
  2003年   24篇
  2002年   11篇
  2001年   15篇
  2000年   15篇
  1999年   5篇
  1998年   10篇
  1997年   13篇
  1996年   9篇
  1995年   13篇
  1994年   6篇
  1993年   4篇
  1992年   4篇
  1991年   6篇
  1990年   3篇
  1989年   10篇
  1988年   3篇
  1987年   5篇
  1986年   3篇
  1985年   4篇
  1984年   7篇
  1983年   8篇
  1982年   7篇
  1981年   6篇
  1980年   4篇
  1978年   4篇
  1977年   5篇
  1976年   8篇
  1974年   8篇
  1970年   3篇
  1969年   3篇
排序方式: 共有714条查询结果,搜索用时 15 毫秒
51.
52.
Management of swine waste generated in the United States is a challenging problem facing engineers, farmers, scientists, regulators, and policy-makers. Technologies for processing and storing swine waste have not been fully developed and refined in a manner acceptable to the public and environmental regulators. The primary concerns with improperly disposed swine waste are the effects on human and livestock health, surface and groundwater quality, air quality, and conservation of nitrogen fertilizers (Hagenstein 2003 Hagenstein, P. R. 2003. Air Emissions from Animal Feeding Operations: Current Knowledge, Future Needs, Washington, D. C.: National Research Council, National Academy Press.  [Google Scholar]).

The purpose of this study is to demonstrate the concept of target costing by applying it to a very specific example: the production of biomethanol from swine manure. This study summarizes the analyses that outline a design and calculate a preliminary cost estimate for a proposed system for producing biomethanol from swine manure (initial process). In this study the target costing process is demonstrated with calculation of a target cost. This article also demonstrates an application of value engineering as a systematic, interdisciplinary examination of factors affecting the cost of a product so as to find means to fulfill the product's specified purpose at the required standards of quality and reliability and at an acceptable cost.

The article is organized as follows. First, the purpose of applying target costing methodology to the development of marketable by-products from swine manure is outlined. Next, target cost is calculated for biomethanol made from swine manure based on current methanol prices and currently available subsidies for biomethanol made from swine manure. A system for producing biomethanol from swine manure is described. The current cost is calculated for producing biomethanol. Concepts of value engineering are employed to reduce a significant cost component of the initial process resulting in Process II. Finally, value engineering is employed the second time to further reduce the cost of Process II yielding Process III.  相似文献   
53.
What constitutes a potentially hazardous object is often debated. This article analyses the polemic construction and negotiation of risk in the Swedish controversy over the use of antibacterial silver in health care and consumer products. This debate engages the media, government agencies, parliament and government, non-governmental organizations and companies. Texts and websites from these actors were studied using content analysis. Antibacterial silver is construed by some actors as a risk object with harmful effects on a series of objects at risk: the environment, public health, organisms and sewage treatment. In contrast, other actors deny that antibacterial silver is a risk object, instead construing it as mitigating risk. In such a schema, antibacterial silver is conceived of as managing the risk objects of bacteria and micro-organisms, in turn managing the risk objects of infection, bad smell and washing, and in turn helping the environment and public health (objects at risk). The structure of the debate suggests two basic modes of risk communication. First, antibacterial silver is construed as a risk object, endangering a variety of objects at risk, such as organisms, public health, the environment and sewage treatment. Second, this association between antibacterial silver and objects at risk is obstructed, by denying that antibacterial silver is a risk object or by associating silver with the benefit of mitigating risk.  相似文献   
54.
In this work, we are concerned with valuing the option to invest in a project when the project value and the investment cost are both mean-reverting. Previous works on stochastic project and investment cost concentrate on geometric Brownian motions (GBMs) for driving the factors. However, when the project involved is linked to commodities, mean-reverting assumptions are more meaningful. Here, we introduce a model and prove that the optimal exercise strategy is not a function of the ratio of the project value to the investment V/I – contrary to the GBM case. We also demonstrate that the limiting trigger curve as maturity approaches traces out a nonlinear curve in (V, I) space and derive its explicit form. Finally, we numerically investigate the finite-horizon problem, using the Fourier space time-stepping algorithm of Jaimungal and Surkov [2009. Lev´y based cross-commodity models and derivative valuation. SIAM Journal of Financial Mathematics, to appear. http://www.ssrn.com/abstract=972837]. Numerically, the optimal exercise policies are found to be approximately linear in V/I; however, contrary to the GBM case they are not described by a curve of the form V*/I*=c(t). The option price behavior as well as the trigger curve behavior nicely generalize earlier one-factor model results.  相似文献   
55.
Abstract

The present paper proposes and investigates a procedure for numerical evaluation of the transition probabilities for a time-inhomogeneous Markov process when the intensities are known (estimated). The procedure is based on Taylor-expansion of the transition probabilities linked with the Chapman-Kolmogorov equations.  相似文献   
56.
This Rejoinder responds to criticisms made by Simon Hussain (2011) Hussain, S. 2011. Food for thought on the ABS Academic Journal Quality Guide. Accounting Education: an international journal, 20(6), : 545559. [Taylor & Francis Online] [Google Scholar] about the construction and operation of the Association of Business Schools' (ABS) Academic Journal Quality Guide. In this paper the broad purposes of journal lists and guides are outlined before an account is given of the long history and multiple forms of these lists, particularly in the field of Accounting. Having described the main features of different types of journal list, the advantages and benefits of the approach adopted in the compilation of the ABS Journal Quality Guide is outlined. The paper then ends by noting that one of the copy-editing mistakes identified by Dr Hussain has been rectified, but the remaining concerns about the rating of accounting education and accounting history journals reflect the absence of these titles from journal citation reports and international journal lists. Furthermore, the lower rating of Accounting & Finance research in the RAE2008 in comparison with Business & Management Studies research in the same year and Accounting & Finance research in 2001, has more to do with the way in which the Accounting & Finance Panel calibrated and normalized its judgements than with the ratings contained within the ABS Guide.  相似文献   
57.
Abstract

In this paper asymptotic properties for the risk process will be studied when the number of risk units tends to infinity. The paper extends asymptotic properties for the classical risk process to more general processes. In the classical risk process the claim amounts are assumed independent and identically distributed, and the claim number process is a homogeneous Poisson process.

The key tool is point process theory with associated martingale theory. The results are illustrated by examples.  相似文献   
58.
The ‘right to request’ policy encouraged and supported National Health Service (NHS) community health staff in England to ‘spin out’ services into independent social enterprises. This article considers the processes and outputs of the initiative and reflects on the likelihood of positive outcomes for patients being achieved. It highlights lessons for future programmes seeking to transfer services out of public ownership.  相似文献   
59.
We use the DATAMATION index of the top 50 domestic IT companies (1975–1995) to track persistence and change at the top of the sector. The trends that we uncover are increasing instability, rejuvenation (declining average age of entrants coupled with increasing average age of quitters), democratization (diminishing revenue inequality at the top) and growing supply‐side intertwining of sub‐sectors and industries within IT due to diversification by long‐term survivors.  相似文献   
60.
Summary. If only the strict part of social preference is required to be transitive then Independence of Irrelevant Alternatives implies that there is a coalition containing all but one individual that cannot force x to be socially ranked above y for at least half of the pairs of alternatives (x,y). Received: August 29, 1996; revised version: March 24, 1997  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