The effect of information on consumers' willingness to pay for natural and organic chicken

This study examined the effect of definitions for organic and natural on willingness to pay a premium for organic over natural chicken. Data were collected using surveys and experimental auctions that were conducted before and after information was presented. Before information, approximately two‐thirds of participants inaccurately equated the requirements of natural with those for organic. After information, nearly 50% increased their premium, while 30% decreased their premium. Logistic regression results showed that consumers who had overestimated the requirements for natural were most likely to have an increased premium after information, with significantly higher bids for organic. For those who decreased their premium after information, awareness of consuming genetically modified (GM) foods was a key variable. The non‐genetically modified (non‐GM) requirement of organic appears to be of low value to some consumers. Overall, consumer confusion regarding organic and natural standards may be having substantial impacts on the two markets.     

机动车尾气排放的危害及控制建议

2009年,我国首次成为世界汽车产销第一大国,机动车尾气排放造成的污染耳益严重,已成为我国大中城市空气污染的主要来源。文章介绍了机动车尾气污染的危害,并提出了针对性的控制措施。     

16Mn无缝钢管的焊接工艺认可试验

拟定焊接工艺,对16Mn无缝钢管进行焊接工艺认可试验。试验结果均符合NK船级规范,说明采用此焊接工艺可保证16Mn无缝钢管的焊接质量。     

苏里格气田定向井钻井技术探讨

苏里格气田地质结构较为复杂,钻采开发以定向井和水平井为主,本文主要是针对定向井施工的工艺技术进行分析探讨,探讨了制约技术提速的瓶颈所在,分析了在不同地层、井深选用不同的钻头及钻具结构及井眼轨迹对提高钻井速度的影响,形成了一套成熟的钻井思路及配套技术;同时也探索了定向井新的提速思路,为下一步持续提速明确了主攻方向。     

大学生课外体育锻炼意识与行为的调查分析

采用问卷调查法、文献资料法和数据统计法,对地方院校大学生参与课外体育活动现状进行调查,探讨大学生课外体育锻炼活动的特点和规律。为培养大学生体育兴趣和终身体育意识,提高课外活动效果,促进高校体育教育的发展提供对策。     

大型物流仓储类建筑防火安全设计方法探析

随着中国物流产业的蓬勃发展,越来越多大型物流仓储中心出现,但是随之而来的一些消防问题也摆在眼前,如防火分区面积过大、疏散问题、消防设施布置等。运用了性能化防火设计评估的方法对类似建筑进行分析模拟,并提出相关优化方案是一个比较可行的解决办法,通过该方法能够提高建筑安全性,增加设施的可靠性。     

油气生产与生态环境协调发展的对策建议

生态环境的可持续发展是制约我国经济社会可持续发展的一大"瓶颈"。我国石油工业的发展不可避免地对生态环境产生了一定的负面影响和破坏,在未来的发展过程中,应不断以创新的理念引领社会责任,加大环保力度,大力实施节能减排、清洁生产、安全生产和节约生产,扎实推进资源节约型、环境友好型企业建设,促进人与自然的和谐发展。     

高压注水在防治14~#煤层采煤工作面煤与瓦斯突出的可行性分析

通过对防治煤层瓦斯及煤与瓦斯突出治理方法的比较,分析煤层高压注水的作用机理及优点,得出了煤层高压注水方法在防治轿子山煤矿14#煤层采煤工作面煤与瓦斯突出是可行的。     

浅谈燃气计量设备的施工及运行管理

本文介绍了影响燃气计量设备计量准确的因素,并从施工、设计及运行管理等环节加强控制,提高计量设备的计量精度,减少产供销差率,保证企业的收入。     

Biofuel policies and the environment: Do climate benefits warrant increased production from biofuel feedstocks?

We examine whether climate benefits warrant policies promoting biofuel production from agricultural crops when other environmental impacts are accounted for. We develop a general economic-ecological modelling framework for integrated analysis of biofuel policies. An economic model of farmers' decision making is combined with a biophysical model predicting the effects of farming practices on crop yields and relevant environmental impacts. They include GHG emissions over the life cycle, nitrogen and phosphorus runoff, and the quality of wildlife habitats. We apply our model to crop production in Finland. We find that under current biofuel production technology the case for promotion of biofuels is not as evident as has been generally thought. Only reed canary grass for biodiesel is unambiguously desirable, whereas biodiesel from rape seed and ethanol production from wheat and barley cause in most cases negative net impacts on the environment. Suggested policies in the US and the EU tend to improve slightly the environmental performance of biofuel production.