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   76篇
  免费   7篇
财政金融   1篇
工业经济   10篇
计划管理   17篇
经济学   16篇
综合类   4篇
运输经济   2篇
贸易经济   6篇
农业经济   19篇
经济概况   8篇
  2022年   2篇
  2021年   3篇
  2020年   1篇
  2019年   1篇
  2018年   1篇
  2017年   3篇
  2016年   4篇
  2015年   3篇
  2014年   4篇
  2013年   8篇
  2012年   8篇
  2011年   7篇
  2010年   7篇
  2009年   10篇
  2008年   3篇
  2007年   3篇
  2006年   6篇
  2005年   2篇
  2003年   2篇
  2001年   1篇
  2000年   1篇
  1999年   2篇
  1996年   1篇
排序方式: 共有83条查询结果,搜索用时 15 毫秒
11.
This article suggests a pricing model for commodities used to produce biofuel. The model is based on the concept that the deterministic component of the Wiener process is not constant and depends on time and exogenous variables. The model, which incorporates theory of storage, the convenience yield and the seasonality of harvests, was applied in the Brazilian sugar market. After predictions were made with the Kalman filter, the model produced results that were statistically more accurate than those returned by the two‐factor model available in the literature.  相似文献   
12.
国内外丁二烯发展概况   总被引:1,自引:0,他引:1  
西方对国内外丁二烯生产技术现状,发展动向,以及市场供需状况作了概要叙述。  相似文献   
13.
The introduction of the flex-fuel cars in the Brazilian market in 2003 changed considerably the consumer decision-making process. Prior to this date, it was necessary to choose the automobile type only by gasoline or by ethanol fuel; today it is possible to choose a car type with both fuel options. This flexibility generates economic advantages for his owner, but what are the financial benefits of a flex-fuel car in comparison with a car using only gasoline? Geographically, where is the owner of the benefits from this flexibility located? This article presents an empirical application of the Real Options Theory in the analysis of the flex-fuel car option for five geographic Brazilian regions: Northern, Northeastern, Central-Western, Southeastern and Southern. The regional price differences as well as the consumer preferences of these regions were met. For this purpose, historical fuel prices were considered stochastic and following a Mean Reverting Stochastic process. The prediction and option values were generated by a Monte Carlo simulation. The results indicated that the option embedded on the Brazilian flex-fuel car adds considerable value to the owner in all regions and car models considered, with the Southeastern Region receiving most benefits by the flex option.  相似文献   
14.
Valuing climate protection through willingness to pay for biomass ethanol   总被引:3,自引:0,他引:3  
This study uses a multi-part, split-sample contingent valuation method (CVM) and fair share (FS) survey to better understand the public's valuation of mitigating global climate change through its willingness to pay for biomass or “cellulosic” ethanol. In addition to a basic CVM question, a related scenario was developed that asked half of the survey respondents to state their fair share cost to lessen a potential food shortage in the next decade, also through the expanded use of cellulosic ethanol. Three alternative biomass feedstocks were assessed: farming residues, forestry residues and paper mill wastes, and municipal solid wastes. Overall a slightly larger proportion of respondents were WTP extra for cellulosic ethanol in the basic CVM scenario than in the FS scenario, though no significant differences were found in the WTP for the different feedstocks. Bid curve lognormal regression results for the two models were similar, supporting the idea that asking a FS rather than a conventional WTP question may be justifiable in some circumstances, such as in cases of a national emergency.  相似文献   
15.
This paper deals with an estimation of phosphate mining cost function. Here, it is argued that other characteristics of reserves, besides their size, could be quite important in the cost function. The result of a cross-sectional analysis of phosphate mining in the world shows that reserve size and average total cost have a positive and modest statistically significant relationship in one of the two models. Among many qualitative characteristics and location factors tested in this paper, overburden, grade, ore/product ratio, water availability, and the price of capital are significant with expected signs. Finally, the results confirm the existence of economies of scale in phosphate mining which seem to be more related to mining technology than to reserve size.  相似文献   
16.
Windows8应用商店开发是微软的一个全新开发技术,本文详细介绍了一款基于win8的天气新闻类应用在开发过程中的设计思路,用到的相关技术:如何使用API,如何提取动态网页中的数据,如何根据动态改变的温度值绘制出正确的温度曲线。应用最终的成功开发表明,设计达到了最初的预期要求,并且对类似应用的开发与研究起了较好的借鉴作用。  相似文献   
17.
The use of corn as an ethanol feedstock has been stimulated by US biofuels policy. This has changed both the position and the slope of the corn demand curve and increased the pass-through from crude oil to corn prices. The principal constraints on ethanol consumption and production have been regulation (the biofuels mandate), capacity constraints in ethanol refining and the blend wall, which puts a ceiling on the ethanol content of gasoline. The incidence of these constraints has varied over time. We model these impacts within the competitive storage model using structural break regression analysis. Our analysis shows that the pass-through has varied over time in relation to the share of ethanol in total US corn use. Our analysis provides robust empirical evidence of an increase in the pass-through from crude oil to corn prices over the period from the start of the century to a high level over 2004–2008 when corn use in ethanol was growing very fast. This enhanced sensitivity was driven by competition for corn as an ethanol feedstock with stock demand exerting strong upward pressure on the corn price.  相似文献   
18.
19.
本文通过实验室模拟仓实验,研究了碎麦提取物与锈赤扁谷盗Cryptolestes ferrugineus、、锯谷盗Oryzaephilus surinamensis、赤拟谷盗Tribolium castaneum、玉米象Sitophilus zeamais、米象Sitophilus ory zae、谷蠹Rhyzopertha dominica信息素提取物混合诱捕储粮害虫效果的影响:本实验应用6种储粮害虫信息素提取物与碎麦提取物混合分别对多种储粮害虫进行诱捕,发现当多种害虫共存时,碎麦提取物与害虫信息素提取物混合对同种害虫的诱捕超过了单独使用碎麦提取物或同种害虫的信息素提取物的诱捕效果,而对于其它害虫的诱捕也都有较显著的增强作用。如碎麦提取物与米象信息素提取物混合除了对米象诱捕有增强作用外,对玉米象也有较好的诱捕作用;结果再次证明昆虫信息素结合食物引诱剂对监测害虫,特别是储粮害虫有较好的增效作用。  相似文献   
20.
This study reveals five critical areas that Brazil's sugarcane‐based ethanol industry could capitalize on to incorporate sustainability into their firms' strategies. The emergent theoretical framework represents a starting point for further investigations aimed at integrating the sustainability construct and strategies for the industry. A growing body of literature calls for strategic management to adapt to complex and ever‐changing environments and sustainability trends. For many firms in developing economies, sustainability remains isolated from mainstream strategy, resulting in reactive approaches on the part of management. A qualitative research method – grounded theory – was used to induct from data. Five themes emerged from the analysis providing guidance on where sustainability‐related strategies ought to begin. This research posits that existing sectoral innovation systems could be used to channel sustainability‐driven innovations. In addition, a combination of public and private efforts to foster innovations based on the emergent themes could increase the value of industry under study, while lessening its social and environmental footprint. Copyright © 2012 John Wiley & Sons, Ltd and ERP Environment.  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