汶川地震灾区绿色旅游发展研究

绿色旅游是旅游业发展过程中在外生因素诱导下的内生的动态创新。根据绿色旅游的内涵,汶川地震灾区绿色旅游系统主要包括绿色旅游供给、绿色旅游中介以及绿色旅游需求3个子系统。绿色旅游资源与环境的恢复和保护性利用以及绿色旅游市场的恢复和开拓,是当前地震灾区绿色旅游业发展的所要解决的核心问题。而解决这些问题的基本路径就是旅游产品开发、旅游制度安排和旅游市场运作的创新。     

Competitive Storage,Biofuels and the Corn Price

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.     

红景天黑玉米复合功能饮料的研制

用乙醇提取法从红景天根茎中提取分离得到有效成分红景天甙提取物,并与黑糯玉米原料配伍,制成风味独特的红景天黑玉米复合功能饮料。经正交设计试验得到优选的工艺参数和配方,即红景天甙粗品用量0.05%,玉米提取液用量25%,蔗糖用量9%,柠檬酸用量0.20%。     

对提升大企业核心竞争力的思考

本文认为,与发达国家的大企业相比,我国的大企业规模偏小,效率不高,技术创新能力较差,国际化水平较低,体制改革亟待深化。提升大企业核心竞争力,应增强企业技术创新能力,培育企业核心竞争力;集中企业资源从事某一领域的专业化经营,逐步形成自己在经营管理、技术、产品、销售、服务等方面与同行的差异;从竞争对手和市场空缺中寻找机会,建立自己的比较优势,并构建支撑这种优势的潜在核心能力;整合核心资源,进行重组,加速信息化建设。     

高油玉米及其产业化发展

本文主要论述了高油玉米的营养价值、经济价值、发展前景以及高油玉米深加工方向和产业化发展的策略。     

2020年新收获玉米质量监测分析

目的:为及时了解2020年辽宁地区玉米的质量状况,为中央储备玉米收购提供科学依据,对新收获玉米质量情况进行监测.方法:本次监测采取田间取样为主、庭院取样为辅的方法进行,本着有代表性和重点突出的原则选择3～5个乡,每乡选择3～5个自然村,每个村选择不少于5个有代表性的农户.将所采集的村级样品混合均匀,形成一份样品.共采集...     

A Methodology for Farm-Level Economic Analysis of Soil Erosion Effects Under Alternative Crop Rotational Systems in Ontario

Multiperiod linear programming techniques are used to evaluate comparative profitabilities and soil erosion rates for corn grown monoculturally and in rotation with a) soybeans, b) soybeans and oats, c) barley, and d) alfalfa on moderately sloping land with medium loam soils in southern Ontario. Attention is focussed on the case of a highly leveraged recent entrant to farming with heavy debt servicing needs and potential cash flow constraints. Monocultural corn was found to be more profitable than any of the rotational systems, with corn-soybeans rotations the next most profitable and corn-barley rotations the least profitable. Corn-soybeans caused the highest soil erosion, followed by continuous corn, with corn-alfalfa rotations causing the least. Les techniques de programmation linéaire multipériode sont utilisées pour évaluer et comparer les niveaux de profit et les taux d' érosion de sols agricoles moyennement argileux pour des systèmes de production de grandees cultyres localiées dans le sud de l' ontario et produisant, soit du mais en régime de monoculture, soit du mais en rotation avec: a) du soja, b) soja et avoine, c) orge. et d) de la luzerne plantée sur des terrains à pentes modérées. L' analyse developpée dans cet article met l' accent sur des agriculteurs récemment installés, disposant de beaucoup d' actifs, mais également, ayant des besoins énormes d' emprunts et, par conséquent, soumis à des contraintes potentielles sur leurs cash-flows. Les résultats obtenus montrent que le système de production, mais-monoculture, est le plus viable de tous les systèmes etudies. Parmi les systemes de production reposant sur une rotation culturale, il s' avère que celui combinant maïs et soja vienne en seconde position, tandis que un régime cultural fondé sur une rotation maïs et orge donne les pires resultats. Pour ce qui concerne des taux d' erosion des sols, la rotation maïs-soja cause les plus gros dommages. ensuite suivie par le système de production, maïs-monoculture. Finalement, les taux d' erosion les plus faibles ont été obtenus pour la rotation culturale, maïs-luzerne.     

Are Revisions to USDA Crop Production Forecasts Smoothed?

This article uses Nordhaus' framework to determine the efficiency of the revision process for USDA corn and soybean production forecasts over the 1970/1971 through 2004/2005 marketing years. Positive autocorrelation and consistency of directional changes in forecast revisions suggest these forecasts are "smoothed." Evidence is provided that the loss in forecast accuracy due to smoothing is statistically and economically significant in several cases. A conservative bias in farm operators' assessments of yield potential and in the procedure for translating enumerator's information about plant fruit counts into objective yield estimates are identified as plausible sources of smoothing.     

Nonlinear Dynamics and Structural Change in the U.S. Hog–Corn Cycle: A Time-Varying STAR Approach

The linearity of the U.S. hog–corn cycle has been questioned by Chavas and Holt (1991) . Even so, attempts have not been made to model the potential nonlinear dynamics in the hog–corn cycle by using regime-switching models. One popular alternative is Teräsvirta's smooth transition autoregressive (STAR) model, which assumes regime switching is endogenous and potentially smooth. In this article, we examine monthly data for the U.S. hog–corn cycle, 1910–2004. A member of the STAR family, the time-varying STAR, is fitted to the data and its properties examined. We find evidence of nonlinearity, regime-dependent behavior, and time-varying parameter change.     

The Term Structure of Implied Forward Volatility: Recovery and Informational Content in the Corn Options Market

Using a flexible method, we develop the term structure of volatility implied by corn futures options with differing maturities, and evaluate its ability to predict subsequent realized price volatility. The implied forward volatilities anticipate realized volatility well. For the nearby interval, the implied forward volatilities provide unbiased forecasts, and are superior to forecasts based on historical volatilities. For more distant intervals, early-year options predict the direction and magnitude of future volatility changes about as well as a three-year moving average and better than a naïve forecast. However, later-year options display less forecast power in part due to reduced trading activity.