共查询到20条相似文献,搜索用时 93 毫秒
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分子印迹技术具有预定性、识别性和实用性,在农残检测中具有广阔的应用前景,已成为当前有机磷农药检测领域研究的热点之一。本文概述了分子印迹技术的原理特点,阐述了其在有机磷农药检测中的应用及研究现状,并展望分子印迹技术在农药检测中的发展和应用前景。 相似文献
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聚丙烯酰胺(HPAM)是一种水溶性高分子聚合物,因其良好的絮凝和增稠性,被广泛用于石油工业领域。随着聚合物驱三次采油技术的推广,聚合物对近井地带的堵塞会降低产油率,同时含聚污水也对环境和人体造成危害。因此寻找高效降解HPAM的微生物用于解堵和去污已成为当前研究的热点。文章综述了HPAM在石油工业中的应用、目前国内外在HPAM降解菌筛选方面的研究进展,并讨论了HPAM生物降解的未来发展方向。 相似文献
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近年来,高毒农药的大量使用对环境的负面影响已引起世界范围的广泛关注。因此,许多国家都制定法规禁止或限制高毒农药的使用。我国是高毒农药生产大国,6个高毒有机磷杀虫剂(甲胺磷、久效磷、对硫磷、甲基对硫磷、氧乐果、敌敌畏)的产量占全国农药总产量的1/3以上,其中高毒的甲胺磷农药一个品种的产量就达7.2万吨。为此,中国农药工业“十五”发展规划中要求,彻底削减高毒有机磷杀虫剂,大力开发新型高效替代品种。近年来,高毒有机磷农药替代品种的开发已成为我国农药研究开发的热点,其市场前景非常广阔。一、低毒有机磷杀虫… 相似文献
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An experiment was conducted in France to evaluate the impact of health and environmental information on consumers’ choices between conventional and organic apples. Results show that additional and precise messages about both pesticides use and pesticides residues significantly impact consumers’ choices between both products. The experiment also studied the effect of a new label signaling apples that only use few pesticides compared to conventional apples. With elicited willingness-to-pay, we show that the introduction of this new label increases the average participants’ surplus whatever the information context for participants, because of a higher quality compared to conventional apples and a lower price compared to organic products. In order to complement this label, a minimum-quality standard imposing the use of few pesticides is socially optimal when initial participants’ knowledge is limited. 相似文献
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In the United States, the Environmental Protection Agency (EPA) registers pesticides and sets crop-specific tolerances while the Food and Drug Administration (FDA) enforces EPA regulations by testing plant-based foods for pesticide residues. Pesticide treatment histories are almost always unknown, especially on imported produce, posing an empirical question: to what extent do FDA’s residue testing methods used on imported produce correspond to the pesticides used on the crops? In this article I show that FDA residue testing would have missed residues of the majority of pesticides used on two crops exported to the US from Costa Rica in 2003, suggesting that FDA residue testing on imported produce is inadequate in its coverage. Policy recommendations discussed include better communication of US tolerances to exporters around the world; increased testing for pesticides, especially fungicides, that are currently not part of FDA’s regular testing procedures; and the creation of price floors and fair trade relationships in the transnational vegetable market to support farmers’ attempts to comply. 相似文献
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In this paper we study the impact of the regulations on Maximum Residue Levels (MRLs) of pesticides on the trade of apples and pears and related processed products with the aim of understanding how their similarity (or dissimilarity) affect trade. Most studies investigate the impact of sanitary regulations introducing directly in the analysis the MRL put in force in the importing country. They introduce in the analysis the level of the regulation in the importing country without taking into account the rule in force in the exporting country. Rather than focusing on a particular pesticide we take into account the entire list of substances set out by the various regulations. We then build a similarity index and introduce it into a gravity equation to assess the impact of the differences in MRL of pesticides on trade. Results suggest that the differences between regulations matter and may, in some case, hinder trade. 相似文献
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Karl D. Majeske Terri Lynch-Caris Gary Herrin 《International Journal of Production Economics》1997,50(2-3)
This paper suggests evaluating field performance by analyzing hazard plots of the random variable time to first warranty claim. This approach corrects biases that arise when a single member contributes many repairs to the repair population and allows comparing the empirical lifetime distribution with the parametric model assumed at product design (e.g., Exponential or Weibull). Using automobile warranty data we demonstrate how using too broad a scope can mitigate changes in field performance by aggregating improving and degrading components. When comparing warranty performance across model years, the analyst should adjust the hazard plots to reflect common field service time. 相似文献
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Vertical Foreclosure in Broadband Access? 总被引:2,自引:0,他引:2
The merger of AOL and Time Warner involved a vertical combination of the largest Internet content provider and aggregator and a large cable system operator which offers a conduit through which broadband customers can access Internet content at high speeds. We consider the economic incentives of such a firm to engage in two distinct vertical foreclosure strategies: (1) conduit discrimination—insulating its own conduit from competition by limiting rival platform distribution of its affiliated content and services, and (2) content discrimination—insulating its own affiliated content from competition by blocking or degrading the quality of outside content. 相似文献
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T.L.V. Ulbricht 《Food Policy》1980,5(1):72-73
The seventh report of the UK Royal Commission on Environmental Pollution1 is entirely concerned with agriculture. It notes the marked changes in the industry, since the second world war, which affect the environment, particularly the vast increase in the use of pesticides and nitrogenous fertilizers, and the growth of intensive livestock units, often situated on areas of land insufficient to take the animal excreta generated by them. 相似文献
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Bisheng Du Christian Larsen 《International Journal of Production Economics》2011,133(1):326-333
We study an inventory system controlled by a base stock policy assuming a compound renewal demand process. We extend the base stock policy by incorporating rules for degrading the service of larger orders. Two specific rules are considered, denoted as Postpone(q,t) and Split(q), respectively. The parameter q distinguishes between regular orders (of size less than or equal to q) and larger orders. We develop mathematical expressions for the performance measures: order fill rate of the regular orders and average on-hand inventory level. We make numerical experiments where the postpone parameter t and the base stock levels of each rule are such that all customers (of both order types) are indifferent between the two rules. When comparing the difference in the average on-hand inventory levels, we can then make an assessment of the threshold value of the cost of splitting an order (which may otherwise be hard to quantify) in the rule Split(q). Our numerical results indicate that this threshold value is increasing in the variance of the order sizes. Based on the numerical experiment our conclusion is therefore that when the variance of the order sizes is low, then Postpone(q,t) seems to be a good option, while when the variance is high, then Split(q) is more competitive. 相似文献
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We study levels and trends in agricultural pesticide use for a large cross-section of countries using FAO data for the period 1990–2009. Our analysis shows that a 1% increase in crop output per hectare is associated with a 1.8% increase in pesticide use per hectare but that the growth in intensity of pesticide use levels off as countries reach a higher level of economic development. However, very few high income countries have managed to significantly reduce the level of intensity of their pesticide use, because decreases in insecticide use at higher income levels are largely offset by increases in herbicide and fungicide use. The results also show very rapid growth in the intensity of pesticide use for several middle income countries such as Brazil, Mexico, Uruguay, Cameroon, Malaysia and Thailand. Complementing our analysis with data from the Rotterdam Convention on Prior Informed Consent (PIC), we show that hazardous pesticides covered in the PIC procedure are more weakly regulated in lower than in higher income countries. We discuss the policy challenges facing developing countries with a rapid growth in pesticide use and recommend a four-pronged strategy, including an environmental tax on pesticides with revenues allocated to long-term investments in awareness building, the development of integrated crop management methods and the setting of food safety standards. The interactions between these measures should help contribute to the effectiveness of the overall strategy package. 相似文献
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章杰 《石油化工技术经济》2004,20(4):1-4
欧盟公布的《未来化学品新政策》白皮书实际上是一种新的绿色壁垒和贸易壁垒形式。它给我国的化工行业带来了新的严峻的挑战 ,将使我国的染料、颜料、农药、有机中间体、纺织品等的出口成本、创制成本大幅提高 ,制约了这些产品的出口和发展。应对措施是 :强化观念转变 ,提高产品质量和检测技术水平 ;强化体制改革 ,积极开发新产品 ,从而在面对欧盟新政策的挑战中争得主动 ,赢得胜利。 相似文献