铁观音茶梗颗粒在卷烟滤嘴中的应用初探

通过SEM和顶空-SPME-GC-MS方法对铁观音茶梗进行了分析,并结合卷烟感官质量评价对铁观音茶梗颗粒在卷烟滤嘴中的应用可行性进行了初步探讨,结果表明:①铁观音茶梗颗粒具有疏松多孔结构,有利于截留烟气中的气溶胶粒子;②铁观音茶梗颗粒中含有与烟草致香成分相同的物质;③铁观音茶梗颗粒能够与烟草自身的香味协调,具有增补烟香、改善卷烟抽吸品质的作用。     

木材颗粒在卷烟滤嘴中的应用研究

通过电镜、比表面积及微孔物理吸附仪对木材颗粒表面形貌和比表面积进行表征。在卷烟对比实验中,研究木材颗粒复合滤棒和未采用木材颗粒醋纤滤棒的吸附性能。结果表明,木材颗粒表面呈鱼鳞状,具有介孔吸附材料特性;木材颗粒复合滤嘴可以降低卷烟主流烟气中的焦油和7种有害物质,对比未使用木材颗粒复合滤嘴下降幅度分别达到了焦油8.57%,CO 2.17%,B（a）P 22.22%,NNK 4.50%,巴豆醛3.49%,HCN 20.37%,氨离子3.77%和苯酚21.16%;木材颗粒复合滤嘴可以提升烟气浓度,增加烟香丰富性和改善舒适性。     

微波膨胀烟梗颗粒的顶空-SPME-GC-MS分析

为评价滤嘴中微波膨胀烟梗颗粒对卷烟香气的影响,在40,60,80℃三个顶空温度条件下,采用顶空-SPME-GC-MS分析方法对微波膨胀烟梗颗粒的挥发性致香成分进行分析。结果表明,膨胀烟梗颗粒可以释放致香成分,并且随着温度的升高,所产生的致香物质种类增多,致香成分构成发生较大改变,醛酮类致香成分所占的比重越大,膨胀烟梗颗粒的增香效果更显著。     

GC-MS法测定电子烟烟气中的苯并[a]芘

采用气相色谱-质谱联用法(GC-MS)测定电子烟烟气中的苯并[a]芘,电子烟样品在ISO标准抽吸模式,采用单层剑桥滤片对电子烟烟气释放物中的粒相部分进行捕集。待抽吸完毕后,将剑桥滤片以环己烷溶液超声萃取并浓缩用以测定。该方法中苯并[a]芘的检出限为4.5 ng/m L,定量限为15 ng/m L,样品中苯并[a]芘加标回收率在95.5%~97.6%之间。结果表明:该方法具有基质干扰少、定量准确、灵敏度高等特点。     

不同抽吸模式对卷烟主流烟气中苯并[a]芘的影响研究

为考察不同抽吸模式对卷烟主流烟气中苯并[a]芘释放量的影响,本研究采用ISO、Massachusetts、Health Canada和补偿抽吸4种抽吸方式分别抽吸了5种卷烟样品,采用气相色谱-质谱联用法测定了主流烟气中的苯并[a]芘释放量。研究表明:与ISO方案相比,采用Massachusetts、Health Canada和补偿抽吸的抽吸方式,卷烟主流烟气中苯并[a]芘释放量均有所提高。     

表面活性剂改性凹土及其对炼油废水中苯并[a]芘的吸附性能

采用表面活性剂对凹土进行改性,并采用X射线衍射、傅里叶变换红外光谱和热分析对改性凹土进行表征,同时考察了其对炼油废水中苯并[a]芘的吸附性能。结果表明,表面活性剂对凹土改性仅发生在凹土表面,改性未改变凹土自身的晶体结构和空间排布。改性凹土对炼油废水中苯并[a]芘的饱和吸附量为889.56μg/g。     

气相色谱法测定沥青中苯并[a]芘的含量

建立了一种煤焦油沥青中苯并[a]芘含量的气相色谱测定方法,该方法采用SE-54毛细管色谱柱、FID氢火焰离子检测器,以外标法定量分析。结果表明,测得结果线性关系良好,结果准确,操作简单,灵敏度高。     

氧化节杆菌与苯并[a]芘-镉交互作用机理

利用HPLC、FTIR分析技术,研究了氧化节杆菌(Arthrobacter oxydans)对水体中苯并[a]芘(BaP)-镉(Cd)复合污染物交互作用机理。结果表明,BaP、Cd及BaP-Cd复合污染均对菌株的正常生长产生影响,其影响程度为:BaP-CdCdBaP;使用该菌投加到BaP、Cd浓度均为1mg·L-1的BaP-Cd复合污染无机盐溶液中,30℃、130r·min-1,培养5d后,体系BaP、Cd的残留量分别为0.39、0.65mg·L-1;添加一定浓度的H2O2并保持体系呈偏碱性更适于该复合污染的处理。红外扫描分析显示,在微生物作用下,BaP的结构发生改变,菌株降解BaP和吸附Cd的过程主要与羟基、CC键、酰胺基团和C—H键有关。     

高效液相色谱法检测植物油中苯并[a]芘的含量

建立并验证高效液相色谱法检测植物油中苯并[a]芘的含量.将植物油样品溶于正己烷中混匀,用苯并[a]芘固相萃取柱净化,用正己烷洗脱苯并[a]芘,荧光检测器检测.苯并[a]芘在0.1～100μg/kg浓度范围内线性相关系数r2=0.9999,本方法平均回收率为96.95%～101.30%,相对标准偏差RsD为0.980%～...     

香烟烟雾中的毒物及其危害

香烟及其烟雾中含有3800多种化合物,其中有毒物质达几百种,至少有43种是致癌物质。本文仅对尼古丁、烟焦油、苯并[α]芘、二甲基亚硝胺、一氧化碳、甲醛、放射性物质等毒物及其危害作以简单介绍。     

生物滤池-活性污泥法处理啤酒废水的实践

衡阳啤酒厂废水处理站设计规模为2100m^3/d;进水CODCr=800-1500mg/L,BOD5=400-800mg/L,SS=300-600mg/L。采用高负荷生物滤池－活性污泥法处理工艺,运行表明出水水质达到GB8978－1988污水综合排放标准中规定的一级标准,且投资省。     

Effects of calcination condition on expansion property of MgO-type expansive agent used in cement-based materials

Previous research indicated that the expansion property of MgO-type expansive agent (MEA) depended strongly on the calcining conditions, i.e. kiln temperature and residence time. However, the intrinsic effect of calcination condition on the expansion property of MEA has not been clearly demonstrated. In the present work, the effects of calcination condition on the microstructure, hydration activity, and expansion property of MEA have been investigated, and their correlations are also studied. Results indicate that the microstructure of MEA is the intrinsic factor that controlling its expansion property, which is influenced by the calcination condition. MEA produced under higher temperature and longer residence time has less interior pores, larger crystal size of MgO, and smaller specific surface area, thus resulting in lower hydration activity and slower expansion at early age, but larger “ultimate” expansion at late age. While, a new expansion model of MEA is proposed to explain these results.     

高温快速萃取技术和转台过滤机的应用

1991年投产的 1.5万 t P2 O5/ a装置 ,经采用高温快速萃取技术与 78m2 转台过滤机 ,并通过实践摸索过程 ,采取若干技术措施 ,解决了滤盘结块 ,滤布需频繁更换等问题。技改后使装置生产能力达 7万 t P2 O5/ a,滤布使用寿命延长至 2 0～ 2 2天 ,磷石膏 w(P2 O5水 )从 0 .4 %～ 0 .6 %降低到 <0 .1%。     

miR-34a过表达对小鼠脑皮质神经干细胞中巢蛋白表达的影响

目的探讨miR-34a(microRNA-34a)过表达对小鼠脑皮质神经干细胞(Neutral stem cell,NSCs)标志物巢蛋白(Nestin)表达的影响。方法通过神经球(Neurosphere)形成试验原代培养ICR胎鼠脑皮质NSCs,在脂质体2000的介导下分别转染miR-34a模拟物(mmu-miR-34a mimics)及其阴性对照(mmu-miR-34a control),另设脂质体对照组(仅转染脂质体)及空白对照组,转染48 h后,采用real time RT-PCR检测各组细胞中miR-34a的表达水平及Nestin基因mRNA的转录水平,Western blot检测Nestin蛋白的表达水平。结果 miR-34a模拟物转染后,显著上调了miR-34a在NSCs中的表达水平(P<0.01);miR-34a的过表达显著下调了NSCs中Nestin基因mRNA转录及蛋白的表达水平(P均<0.01)。结论外源性过表达miR-34a可下调NSCs中Nestin基因mRNA的转录水平及蛋白的表达水平,为NSCs的增殖、分化调控的研究提供了新的理论依据。     

神经干细胞的三维培养及其在神经疾病中应用的研究进展

作为从二维(two-dimensional,2D)培养衍生出的新技术,神经干细胞(neural stem cells,NSCs)的三维(threedimensional,3D)培养不仅能够模拟脑内微环境,更好地维持NSCs增殖及分化能力,还能进一步形成脑类器官。3D培养NSCs及脑类器官均可作为有效的体外细胞模型,不仅能模拟神经疾病的发病过程,还可应用于高通量药物筛选;另外,利用NSCs移植及定向分化等特征修复和替代死亡的神经细胞,可延缓或抑制阿尔茨海默症(alzheimer disease,AD)等神经系统疾病。NSCs的3D培养将有助于研究者更好地理解大脑发育过程,以及神经系统疾病特别是神经退行性疾病的发病机制,同时有助于寻找药物靶点和药物开发。由此可见NSCs的3D培养展现出巨大的优势,具有良好的应用前景。本文对NSCs的特性和3D培养方式,及其在神经疾病中应用的最新研究进展作一综述。     

Investigation of cytochrome P450 mediated benzo(a)pyrene hydroxylation in Aspergillus fumigatus

Microsomal fractions of Aspergillus fumigatus exhibited a reduced carbon monoxide difference spectrum with a maximum at 448 nm and a substrate-induced Type I spectrum on addition of benzo(a)pyrene. Metabolism of benzo(a)pyrene, as measured using the aryl hydrocarbon hydroxylase assay, was found to be P450-dependent and activity was observed to have a K_m of 82 μM and V_max of 33·3 pmol min⁻¹ mg⁻¹ protein. P450 productivity was investigated during growth from spore inocula and observed to be constant until the stationary phase, where the specific content declined to undetectable levels. The specific content of P450 was found to increase in higher concentrations of glucose.     

Preparation of Test Material and Evaluation of a Proficiency Test for Official Food Control Laboratories on the Determination of Polycyclic Aromatic Hydrocarbons in Baby Food

A proficiency test on the determination of polycyclic aromatic hydrocarbons (PAHs) was organized by the German National Reference Laboratory for PAH in 2010. The test samples were produced by spiking cereal-based instant baby food with PAHs at concentration levels between 0.6 and 3.8 μg/kg; homogeneity and stability of the test material were verified before sample dispatch. Twenty-one official laboratories from Germany and Austria participated in the test and the evaluation of the test was done by applying methods of robust statistics. The individual performance was assessed with the help of z-scores. As to the quantitative results, the dispersion of data for the most important group of benzo(a)pyrene (BaP), benz(a)anthracene (BaA), benzo(b)fluoranthene (BbF), and chrysene (CHR) appeared to be acceptable, with a relative robust standard deviation ranging from 13.2% for BbF to 26.7% for BaA. In total, the performance of one laboratory had to be rated as unsatisfactory because of a result for BaP outside the limits of tolerance. The methods applied in the test may be considered to be comparable, as no significant effects in the distribution of data could be attributed to certain analytical procedures.