卷烟主流烟气中巴豆醛在线光谱分析方法研究

卷烟主流烟气是卷烟燃烧时被人体吸食到体内的主要气体,其减焦降害已成为全社会高度关注的问题。在各种卷烟主流烟气组分中,巴豆醛以其强烈的基因毒性,成为国家规定的卷烟中七种主要有害指标物之一。传统的巴豆醛分析方法大都采用高效液相色谱法等实验室分析方法,需繁琐的样品前处理过程,无法测量巴豆醛的实时浓度,难以准确评估巴豆醛对人体健康的影响。为了快速、准确地检测卷烟主流烟气中的巴豆醛组分,本研究搭建了一套可以直接与吸烟机耦合的傅里叶红外光谱分析系统（FTIR）,并创新性开发过采样数据驱动光谱分析方法（ODDSA）,从复杂、变动的卷烟主流烟气中准确提取巴豆醛的光谱组分信息。ODDSA方法从实验设计入手,采用随机设计的思路尽可能模拟实际卷烟样品的分布范围,以构建具备良好光谱数据结构的样品集。在此基础上,创新性地将高密度小波变换引入红外光谱数据的处理过程中,以时/频双域过采样的方式提升了光谱解析分辨率,进而降低了其他基质组分对巴豆醛光谱信息的干扰。最后,发展改良竞争自适应重加权采样方法,从多倍冗余的高密度小波系数中准确提取待测物质的最佳变量组合,由此构建高质量的巴豆醛光谱定量分析模型。为了验证ODDSA方法的有效性,实验中采集了15种典型市售卷烟品牌,每个品牌在线采集8支样品的主流烟气红外光谱,随后采用随机挑选的25个验证集样本对ODDSA方法进行验证。结果表明,检验集的线性拟合系数为0.971,相对均方根误差为5.5%,其预测精度能有效满足卷烟主流烟气中巴豆醛的在线分析需求,并可拓展到环境二手烟气中其他组分的在线监测,进而为吸烟与健康评估提供全新手段。     

敏感问题研究中从调查问题到目标问题的转换模型

针对社会敏感问题,构建了从调查问题到目标问题的转化模型,并以大学生考试心理问题为例,进行了模拟运算,从模拟结果看,通过无敏感化的调查问卷研究敏感问题在技术上是可行的,能够达到较为理想的信度和效度,从而开辟了量化研究敏感问题的新途径.     

多环芳烃的滤纸基质室温磷光法研究

本文以芘为模型化合物,对滤纸基质室温磷光法的重原子进行选择, 并研究了影响磷光强度的因素. 在通氮气情况下,以十二烷基硫酸铊为重原子, 测定了芘、芴、萘三种多环芳烃的室温磷光.实验结果表 明: 芘、萘、芴的最低检测限分别为 1. 5ng、3. 0ng 和 3. 0ng, 相关系数均大于 0. 995, 相对标准偏差均小于 5%.     

Optical inspection by internal reflection and spatial filtering

Some optical techniques for surface inspection applications are described. Paper texture is analyzed by a frustrated-total-internal-reflection method followed by spatial filtering of the diffracted pattern. Fibre-optics and micro-lenses are used to obtain a rugged and flexible sensor. Similar sensors are used for defect monitoring of roughly-polished surfaces. The practical aspects of sensor manufacture, speckle and vignetting considerations are discussed.     

A recursive linear programming analysis of the future of the pulp and paper industry in the United States: Changes in supplies and demands,and the effects of recycling

The impacts of increased paper recycling on the U.S. pulp and paper sector are investigated, using the North American Pulp And Paper (NAPAP) model. This dynamic spatial equilibrium model forecasts the amount of pulp, paper and paperboard exchanged in a multi-region market, and the corresponding prices. The core of the model is a recursive price-endogenous linear programming system that simulates the behavior of a competitive industry. The model has been used to make forecasts of key variables describing the sector from 1986 to 2012, demand for paper would have the greatest impact on the amount of wood used. But the minimum recycled content policies envisaged currently would have no more effect than what will come about due to unregulated market forces.     

A study of dilute tin alloys by x-ray photoelectron spectroscopy

X-ray photoelectron spectra of Pb₉₈Sn₂, Ag₉₅Sn₅, Sb₉₅Sn₅ and Cd_99.6Sn_0.4 have been recorded using a VG Scientific ESCA-3 Mk. II electron spectrometer. In all cases the Sn 3d level in the alloys is compared with the 3d level in pure tin. The binding energy shifts are explained on the basis of electronegativity and near-neighbour interactions. It is found that increased coordination number as well as increased electronegativity of the neighbouring atoms increases the binding energy of the core electron level.     

分子印迹材料选择性截留卷烟烟气中芳胺的研究

采用分子印迹技术合成了一种对1-萘胺有高度选择性的分子印迹聚合物材料。应用固相萃取吸附试验研究了该聚合物对1-萘胺及其结构类似物的选择特性,表明印迹聚合物材料对4种芳胺类物质表现出良好的选择性结合能力。将所制备的印迹聚合物按不同剂量添加到卷烟嘴棒中,考察其对卷烟烟气中芳胺的截留效果。结果显示,该分子印迹材料能选择性截留卷烟烟气中的1-萘胺、2-萘胺、3-氨基联苯和4-氨基联苯等烟气有害成分;当印迹聚合物添加量为50mg时,卷烟烟气中芳胺的降低率达到30%。