氯苯类还原性气氛下高温降解反应机理

氯苯类化合物（CBz）是生活垃圾热处置过程中存在的重要污染物,热解、气化技术能够有效降低热处置过程的CBz排放。为了探究其在热解、气化环境下的降解机理,以1,2,4-三氯苯（1,2,4-TrCBz）为研究对象,进行了1,2,4-TrCBz在中高温段（550—850 ℃）还原性气氛（H₂,CO等）下的降解特性实验,同时通过量子化学计算,利用Gaussian 09W软件模拟了降解过程中可能存在的多条反应路径,并比较了各路径的竞争关系。结果表明温度越高,1,2,4-TrCBz的降解效率越高。降解效率在750 ℃和850 ℃时,分别为14.07%和60.27%,1,2,4-TrCBz分子的C—Cl键解离能在370 kJ·mol⁻¹左右,温度在650 ℃以下时,环境提供的热量不足以使C—Cl键断裂,H₂降低了40 kJ·mol⁻¹左右的C—Cl键断裂所需的能量,提高了降解反应速率。单独的CO不参与1,2,4-TrCBz的降解反应,实验降解特性与N₂气氛相似。CO与H₂共存时,在相同温度下,降解表现呈现H₂>H₂+CO>CO的规律,CO的存在提高了H₂近20 kJ·mol⁻¹的降解反应活化能,从而降低了反应速率。1,2,4-TrCBz的降解过程存在3条有效降解路径,反应更趋向于通过生成1,3-二氯苯（1,3-DCBz）的路径进行。     

Design training and aesthetic evaluation: An intergroup comparison

A number of studies have observed differences in the evaluation of visual, aesthetic stimuli between those with and without professional training in art and design. If exposure to design training underlies such differences it follows that evidence of training effects should be observable when comparing subjects at different stages of design training, and not observable when comparing subjects at different stages of non-design training. In addition, this evidence should be consistent with directional predictions. The study reported in this paper investigated this question using a sample of 192 trained and untrained subjects in an evaluative task. Subjects were from two departments (Design and Computer Studies) of the same educational establishment and comprised balanced groups of lecturers, 1st, 2nd and 3rd year undergraduate students. The results obtained demonstrated evaluative differences and patterns of association both within and between the subject groups consistent with a training hypothesis.     

The behavioral component in the meaning of places

How do people think about the physical setting in the world around them? Part of the answer to this question may be in terms of the behaviors that occur there. To explore people's knowledge of behavior—place associations, twenty places (shown via color photographs) were assessed in five ways: (a) ratings of the place's suitability for each of eleven behaviors, (b) ratings of the expected frequency of occurrence of the eleven behaviors, (c) free listings of reasons for going to each place, (d) free listings of activities-while-there and (e) free listings of activities associated with the place. Results showed that people can distinguish places on the basis of behaviors, that the behavioral component of place meaning is composed of distinct aspects, and that knowledge of behavior is related to a global, overall representation of a place.     

Enzymatic degradation of poly([R,S] β-hydroxybutyrate)

The synthetic analogue of a bacterially produced polyester, poly(-hydroxybutyrate) (PHB) was synthesized from racemic -butyrolactone using anin situ trimethyl aluminum-water catalyst. The polymer was fractionated into samples differing in molecular weight and isotactic diad content. The latter was closely related to degree of crystallinity. The biodegradation of these fractions were examined by monitoring mass loss over time in the presence of anAlcaligenes faecalis T1 extracellular bacterial poly(-hydroxybutyrate) depolymerase. The fraction with high isotactic diad tacticity content showed little or no degradation over a 50 hour incubation period, whereas the fraction of intermediate isotactic diad content degraded in a continuous steady fashion at a rate that was less than that for bacterial PHB. The low isotactic diad fraction underwent a rapid initial degradation, followed by no further mass loss. The presence of stereoblocks in the polymer structure of the various fractions was an influence on the degree of susceptibility towards degradation and is related to sample crystallinity.     

新型絮凝剂聚环氧氯丙烷胺的合成研究

以环氧氯丙烷和二甲胺为原料,乙二胺为交联剂,制备有机阳离子聚合物,研究乙二胺加入量、反应温度、环氧氯丙烷和二甲胺的摩尔比、聚合时间等对聚合物粘度和阳离子度的影响.利用电子透射电镜(TEM)和电子扫描电镜(SEM)对聚合物的结构形貌进行了表征.结果表明,环氧氯丙烷和二甲胺的摩尔比为1.5:1,乙二胺加入量为3%时,聚合物的粘度和阳离子度最大,具有较强的吸附架桥和电中和作用,对染料废水有较好的脱色效果.     

利用交叉组装噬菌体示踪水环境中人源粪便来源的耐药细菌

人类粪便中的耐药细菌(antibiotic resistant bacteria,ARB)及其携带的耐药基因(antibiotic resistance genes,ARGs)可以通过城市污水处理系统排放进入当地水环境,因此,快速准确地探明水环境中粪便污染及ARB情况对于保护生态系统和居民健康具有重要意义.本研究借助噬菌体crAssphage作为新型人类粪便污染特异性指示标记,采集太原市健康人群粪便、晋阳湖、汾河水库、自来水和污水处理厂的样品,首先采用实时荧光定量PCR技术检测样品中人类粪便污染指示标记crAssphage、细菌核糖体16S rRNA基因与耐药基因blaTEM-1 的存在情况;其次针对各类样品进行细菌分离培养与鉴定,完成样品中blaTEM-1耐药菌株及多重耐药细菌的筛选;最后通过构建系统发育树分析菌株的进化关系,探究不同环境介质中细菌之间的相互影响.结果显示crAssphage在晋阳湖、汾河水库和污水处理厂样品中被检出,证明太原市区水环境存在人类粪便污染.本研究共分离鉴定出254株细菌,氨苄青霉素耐药细菌占比最高(74.41％),环丙沙星耐药细菌占比最低(1.97％);耐药基因blaTEM-1在各类样品的菌株中都有检出(22.83％),多重耐药细菌共有79株(31.10％).进化关系分析表明人体肠道与水环境中的耐药细菌具有亲缘关系.上述结果表明太原市水环境受到人类粪便污染的影响,并且可能促进了ARGs和ARB的传播扩散,对人体健康产生威胁.该研究为评估太原市水环境粪便污染情况及ARB分布提供基础数据,为水环境监测保护给出科学依据.     

基于环境一号卫星的PM2.5浓度遥感反演研究

2014年12月29—30日,青岛市发生了一次空气污染过程,利用环境一号卫星CCD遥感影像数据和实测PM_(2.5)浓度数据,分析了该过程前后5 d的实测PM_(2.5)浓度与环境一号卫星CCD遥感影像的DN值之间的相关性,分别按日期和区域建立了反演模型。结果表明,按日期拟合反演模型相关系数为0.02~0.51,按区域拟合反演模型相关系数为0.01~0.80,总体来说,区域拟合结果较好。     

聚乙烯醇包埋奥奈达希瓦氏菌MR-1还原U(Ⅵ)

实验用聚乙烯醇包埋奥奈达希瓦氏菌MR-1制备了包埋微球,并用其对U（Ⅵ）进行还原实验。实验结果表明,当pH=7.0,不同聚乙烯醇浓度对包埋微球的成球性、稳定性和传质性均有影响,制备包埋微球的聚乙烯醇的最优浓度为10%;当U（Ⅵ）浓度为15 mg·L-1,奥奈达希瓦氏菌投加量为6 mL,且奥奈达希瓦氏菌与聚乙烯醇按1∶2的比例进行包埋后,包埋微球对U（Ⅵ）的去除率最高达96.22%。Cu2+、Mn2+、Ca2+等共存离子对包埋微球还原U（Ⅵ）产生影响,2.0 mmol·L-1的Ca2+对包埋微球还原U（Ⅵ）存在微弱的促进作用;2.0 mmol·L-1 Cu2+、Mn2+对包埋微球还原U（Ⅵ）存在不同程度的抑制作用,去除率分别仅为8.14%和65.99%。扫描电镜和电子能谱分析结果表明,铀被微球还原沉积在包埋微球中。     

混合气体爆炸性MFC图形分析

判断混合气体爆炸性常用3种方法,即科瓦德爆炸三角形法、美国矿业局采用的爆炸三角形计算法和最小助燃氧浓度法,然而如何准确、快速、形象地得到分析结果在防灾救灾中是十分关键的.笔者的重点是提供一个图形分析方法解决上述问题.VC++是方法的基本理论依据,用一个实例来验证方法的有效性.总之,研究表明:图形分析法可提高安全管理效率.     

汽车燃料和排放物的快速气相色谱分析

1　IntroductionGaschromatographyisthemostfrequentlyusedmethodsforthespeciationandquantificationoforganiccompoundsingasphaseandliquidphase .Thechemicalanalysisoforganiccompoundsintheautomotivefuelsandexhaustspeciesisanextremelyimportantandcomplexprocedure …