Abuse of smoking methamphetamine mixed with tobacco: II. The formation mechanism of pyrolysis products

The pyrolysis products of smoking methamphetamine mixed with tobacco were determined by gas chromatography (GC) and GC/mass spectrometry (GC/MS) methods. The mainstream smoke contained methamphetamine (14.5% of the initial methamphetamine), phenylacetone (3.1%). N-cyanomethylmethamphetamine (1.9%), trans-beta-methylstyrene (1.7%), N-formylmethamphetamine (1.5%), and other products (each less than 1%). The amount of each pyrolysis product in the sidestream smoke was less than that in the mainstream smoke by a factor of over 5, except for methamphetamine (10.5%) and N-formylmethamphetamine (1.4%). The formation mechanism of these products was investigated, by use of a pyrolyzer, from the standpoint of the material, pyrolysis temperature, and pyrolysis atmosphere. Although several products (for example, dimethylamphetamine and trans-beta-methylstyrene) were formed by thermal self-decomposition of methamphetamine alone, most of the products, except N-cyanomethylmethamphetamine, were formed chiefly by the thermal reaction of methamphetamine with cigarette components. The formation of N-cyanomethylmethamphetamine required air and a high pyrolysis temperature. Air and a high pyrolysis temperature generally accelerated the formation of the pyrolysis products.     

Auctioned oil import licenses

Three times in recent years American Presidents have tried to levy a tax on imported oil in order to decrease the quantity. Three times, the U.S. Congress has blocked the policy, demonstrating that a tax is politically infeasible. As an alternative, we propose an auctioned import license policy, in which the President would have discretion over the quantity of petroleum sold each month. The quantity might be chosen to maintain a certain differential between the domestic and international prices of oil. Under this strategy, licenses would have economic characteristics very similar to those of a tax. The political characteristics, however, would be quite different. Sections of the public would be less likely to perceive licenses as transferring revenues from households to the government and more likely to perceive them as effective in reducing imports. Alternatively, oil import licenses could be used to negotiate with OPEC and other importing nations.The authors wish to thank William Dunn, Robert Walters, Richard Nehring and Charles Phelps for their helpful comments. The usual caveat applies.     

Lewis typing of human bloodstains by enzyme-linked immunosorbent assay (ELISA) using monoclonal anti-Le(a) and anti-Le(b)

The Lewis blood grouping of human dried bloodstains could be determined by an enzyme-linked immunosorbent assay (ELISA) using monoclonal anti-Le(a) and anti-Le(b) antibodies with an avidin-biotin complex (ABC). The bloodstains aged 1 year were used as samples, and approximately 1 mg of the stains was enough to type each Lewis antigen reliably by this method. The Lewis substances of 106 individual stains were correctly typed regardless of their ABO blood group system.     

人类生存的诗意之源--论人与自然环境关系的美学建构

人类生存与发展的需求 ,总是促使其与自然环境保持一种根本性的关系 ,但要真正实现“和谐共存” ,则必须建立相适的制衡机制。其中 ,关键性的问题 ,是要实现对于人自身的调节 ,而调节的重心则是要抑制贪欲 ,高扬诗性 ,建立起富有审美特质的关系。此可谓是当代背景下新的生存理性的自觉     

《大学语文》课与人文精神教育

针对人文精神失落的现状,<大学语文>课应发挥其在大学生人文素质塑造方面的积极功能,使其成为人文精神教育的重要阵地.为此,第一,必须改变教育观念.长期形成的"重知识、重技能、轻文化"的倾向在<大学语文>教学中必须彻底改变,摆正"传道、授业、解惑"三者之间的关系,把"传道"放在首位.第二,改革教学方法和模式.发扬课堂民主,尊重学生个性;加强启发式教学,尝试讨论课和辩论课;搞好课堂设计,处理好"主体"与"主导"的关系.第三,调整教育教学内容及侧重点.利用本学科自身的优势,从文化中弘扬人格魅力;从文化中发掘人性光辉;从文化中感悟人生真谛;并积极加强国际文化融合,适应入世需要,从多方面进行人文精神培养.