氮气中苯系物(高压)标准气体的研制

对高压气瓶中苯系物气体标准样品的制备方法进行了研究,对各种可能影响苯系物气体标准样品量值准确性的因素进行了分析。所制备的苯系物气体标准样品的量值与国外同类标准的量值具有可比性,且具有良好的压力稳定性并能稳定保存18个月。     

掺碳纳米TiO_2光催化降解空气中苯的实验研究

采用火焰化学气相沉积法法制备了掺碳纳米TiO2光催化剂,对催化剂进行了表征。利用自制的连续管式光催化氧化装置研究了掺碳纳米TiO2薄膜对苯气体的光催化降解规律,探讨了相对湿度、初始浓度及苯气体流速等因素对降解率的影响,并与P25粉的光催化性能进行了比较。实验结果表明:在催化剂负载量约为4.7 mg,254 nm和365 nm的8W紫外灯各一盏,相对湿度为80%、苯的初始浓度约为120 mg/m3、苯气体流量为400 mL/min(苯在光催化器中反应时间约为3.5 s)的条件下,苯的降解率可达到15%,高于P25粉的降解效果。     

食品添加剂二氧化碳中苯气体标准物质性能评价方法的研究

介绍了食品添加剂二氧化碳中苯气体标准物质的分析方法和性能评价方法。采用美国Agilent6890N气相色谱仪、FID检测器,在最佳色谱实验条件下对苯的检测限小于10×10^-9,线性误差小于2%。还给出了二氧化碳中苯气体标准物质均匀性、一致性、稳定性（随时间、压力变化）的考察结果。研究成果表明二氧化碳中苯气体标准物质重量配制的相对扩展不确定度小于1.7%。     

喷漆作业排放气体中苯系物的气相色谱测定

通过对喷漆作业气体样品中不同浓度苯系物的测定,建立热解吸气相色谱法,优化了气相色谱的操作条件,提出了保证测定质量的技术关键。适．用于污染源排放气体中苯系物的测定。     

γ-Fe2O3响应苯类气体敏感材料特性研究

从电导控制理论,对掺钇、硫酸根离子等多元化、微结构γ-Fe2O3的热稳定性、响应苯类气体敏感性及其对相邻气体的高选择性,进行了系统研究与机理分析,并用DTA、TEM、RQ-1等方法进行表征与测量.结果表明,掺入适量Y2O3后能使γ-Fe2O3的相变温度提高到618℃,从而改善γ-Fe2O3基气敏元件的热稳定性;硫酸根离子和金离子的适量掺杂有助于提高苯类气体的敏感特性;γ-Fe2O3基体材料的微细化可增强γ-Fe2O3的表面气敏特性.从而为苯类有机气体敏感元件研制提供了一条新途径.     

食品添加剂二氧化碳中苯系列气体标准物质的研究

研究了注射重量法制备食品添加剂二氧化碳中苯系列气体标准物质的实验方法。气体称量装置采用日本Kyoto公司H2-30K型低感量大量程机械天平（30kg,1mg）和瑞士Mettler公司SB-16001粗称气瓶的大量程低灵敏度电子天平（16kg,0.1g）,称量组分气体和稀释气体。用日本Shimadzu L-200D高精密天平（200g,0.05mg）称量带锁注射器注射前后的重量。实验中选取苯含量低于0.01×10^-6的高纯二氧化碳气体,以满足配制1×10^-6标准气体的需求,本项研究苯系列气体标准物质重量制备的不确定度均小于2%。     

液体外标法制备苯标准曲线方法

为了解决《民用建筑工程室内环境污染控制规范》室内空气中苯浓度测定标准曲线制备过程复杂、环境污染较大的问题,将液体外标法用于苯标准曲线的制备。研究了该方法的具体操作条件。分别采用标准气体气相色谱法和标准液体气相色谱法方法测定多个活性碳管吸附解吸率,实验表明两种方法测定结果一致,证明该种制备苯标准曲线的方法简单准确,污染小。     

新装房间内苯的释放规律和传输过程的CFD分析

现代的装修装饰材料会释放大量的有毒有害物质（如苯及苯系物）,污染着室内环境。对于一个新装修的建筑房间,了解其室内建筑材料内苯及苯系物的散发特性和浓度分布规律,从而避免吸入过量的有毒有害物质的,成为人们越来越关心的事。以一户新装修的住宅为例,首先对该房间空气中的气态污染物进行数值模拟,然后分析污染物散发机理及空间传输过程,最后通过总结模拟计算的结果,对如何降低新装修房间内苯的浓度,提出了几点建议。     

基于PIC16F877A的室内有害气体检测仪

设计了一种基于PIC16F877A单片机、能有效检测出甲醛及苯的室内有害气体检测系统,详细描述了该系统的硬件和软件设计方案。软件设计中采用温度补偿技术对测试结果进行了温漂校正,提高了室内有害气体测试的准确度。该检测仪能及时提醒人们居住环境中的有害气体含量,对确保人们居住环境安全有重要意义。     

食品级二氧化碳中苯含量气相色谱分析方法的研究

实验采用气相色谱法分析二氧化碳中的痕量级组分气体——苯。主要影响因素有进样口温度、毛细柱温度、检测器温度、毛细柱流速、尾吹,对各项优化后测得精密度为0．2％,线性误差不大于±2％。该方法快速、准确,可应用于该标准物质的分析定值。     

Porous carbon nitrification process optimization for enhanced benzene adsorption

Benzene is one of the aromatic hydrocarbons co-absorbed with acid gases during amine scrubbing that contribute to deactivation of catalyst in the Claus process. The present work attempts to modify the porous carbon surface through nitrogen group functionalization utilizing melamine as the nitrogen source, adopting Design of Experiments (DOE) with concentration of melamine, duration of impregnation and temperature of impregnation being the process variables, while BET surface area was the response variable. The surface modified samples were subjected to benzene adsorption. The optimal nitrogen content that had minimal pore damage was found to be less than 4.3%, with concentration of melamine being the most significant variable. Surface nitrogen functionalization reduced the surface area whereas the benzene adsorption capacity increased. Benzene adsorption capacity as high as 14.72 mmol/g was recorded at 45°C at a pressure of 235 mbar. Such high adsorption capacities have not been reported in open literature and the nitrogen functionalization augmented the adsorption to the tune of 20 to 30% at a pressure of 100 mbar, and only up to 10 to 15% at higher pressures. The adsorption isotherms as well as the kinetics of adsorption were modelled using the well-known popular models. Further, successful regeneration of the surface modified adsorbents were ensured through adsorption/desorption cycle experiments.     

Hydrogen peroxide and oxygen-hydrogen oxidation of aromatic compounds in catalytic systems containing heteropoly compounds

Hydrogen peroxide and Pt activated mixture of gaseous O(2) and H(2) have been applied to oxidation of aromatic compounds in the presence of redox active heteropoly compounds in the form of acid H(4)PMo(11)VO(40) and tetrabuthylammonium (TBA) salts TBA(4)PMo(11)VO(40) and TBA(4)HPW(11)Fe(OH)O(39). Benzene, toluene and phenol were subjected to hydroxylation of the ring, which was accompanied by secondary oxidation in the reaction with hydrogen peroxide. Oxygenation of toluene was equally directed to the ring and to methyl group. The total reactivity of substrates was increased in the order of benzene相似文献   

Catalytic oxidation of benzene using DBD corona discharges

Plasma oxidation of benzene (C(6)H(6)) in oxygen and nitrogen was investigated using a dielectric barrier discharge (DBD) reactor with or without MnO2 or TiO2 at atmospheric pressure and without external heating except plasma heating. An alternative current power supply was used to generate corona discharges for the plasma oxidation. The energy density was controlled under 200 J/L to keep an increase in gas temperature less than 167 K. C(6)H(6) was oxidized to carbon monoxide (CO) and dioxide (CO(2)). Typically, the energy efficiency at an energy density of 92J/L was about 0.052, 0.039, and 0.024 mol/kWh with MnO2, TiO2, and without MnO2 and TiO2, respectively. Benzene oxidation mechanism was mentioned. A comparison on energy efficiency as a function of initial concentration of hydrocarbons, inorganic sulphur compounds, and chloro (fluoro and bromo) carbons was given.     

EC-HBPE渗透汽化膜的性能

以三羟甲基丙烷为核、二羟甲基丙酸为单体,采用准一步法合成了1~5代脂肪族超支化聚酯(HBPE)。将该聚酯与乙基纤维素(EC)共混制备了EC-HBPE均质膜,以苯/环己烷体系为对象,对该共混膜的溶胀行为和渗透汽化性能进行了考察。结果表明,适量3、4、5代HBPE的加入可以在不降低膜分离因子的同时,大幅度提高膜的通量。在苯含量较低(<10%)的料液中,EC-HBPE的吸附选择性略高于EC,而EC-HBPE液的平衡吸附量明显高于EC。     

A novel solvothermal route to benzene ring-capped oxide nanocrystals

A novel solvothermal synthesis based on the reaction between nitrate and benzene for metal oxide nanocrystals including ZrO₂ and SnO₂ is introduced. The as-prepared nanocrystals are characterized by TEM, XRD and IR techniques in detail, and the possible mechanism of this solvothermal reaction is discussed. Benzene molecules used as capping agent, instead of long-carbon chain molecules, are chemically adsorbed to the surface of the as-prepared oxide nanocrystals, making nanocrystals with long-term stability and good dispersibility in hydrocarbons.     

Tandem fourier transform mass spectrometry studies of surface-induced dissociation of benzene monomer and dimer ions on a self-assembled fluorinated alkanethiolate monolayer surface

A new instrument configuration based on a Finnigan FTMS-2000 platform has been applied to the study of surface-induced dissociation (SID) in this research. Benzene monomer ions C(6)H(6)(+) and dimer ions (C(6)H(6))(2)(+) were impacted on a fluorinated self-assembled monolayer surface at collision energies ranging from 1 to 70 eV. Benzene cations were chosen for this study because the fragmentation characteristics of the molecular cation are well known and its SID has been thoroughly investigated. SID spectra obtained by FTMS-SID are very similar to those reported in the literature for the same surface but exhibit much higher mass resolution. A comparison study of collision-induced dissociation (CID) and SID of benzene molecular cations was performed utilizing the same ICR cell and ion detection protocol. It is demonstrated that SID provides both much higher energy deposition and a narrower internal energy distribution than CID. The present instrument geometry and experimental protocol demonstrate much higher efficiencies than previous SID studies by FTMS and much higher mass resolution than previous SID studies using other types of mass analyzers.     

聚硫醚酮单体4,4’-二氯二苯酮和4-氯-4’-氟二苯酮的合成研究

对氯苯甲酰氯分别与苯、氯苯和氟苯经Friedel-Crafts酰化反应合成了4-氯二苯酮(CBP)、4,4’-二氯二苯酮(DCBP)和4-氯-4’-氟二苯酮(CFBP),收率都在93%以上,粗品含量在98%以上。所有产品均经熔点、HPLC和NMR氢谱表征。DCBP和CFBP的合成,实验显示二氯乙烷作溶剂的结果较佳。     

CS_2萃取毛细柱气相色谱法测定焦化厂区空气中的苯

活性炭富集采样,CS2萃取,毛细柱分离,FID检测,测定焦化厂区空气中苯。在选择的色谱条件下,可以将苯系物样品中的苯、甲苯、乙苯、间、对二甲苯、邻二甲苯、苯乙烯等色谱峰分开,从而实现各组分的单独测定。实验表明,CS2对苯的萃取效果可靠。充分利用标准物质,探讨了该方法的准确度和灵敏度,在较宽的浓度范围内(0.33-50.7μg/mL),可以对焦化厂区空气中的苯进行直接测定,为管理打下基础。     

Natural clinoptilolite–zeolite loaded with iron for aromatic hydrocarbons removal from aqueous solutions

The aim of this work is to explore the potential use as catalyst in aromatic hydrocarbons removal, a natural zeolite loaded with zerovalent iron. For this purpose, an iron precursor, FeSO₄·7H₂O, was first imbibed, later reduced and confined on the surface and/or inside of a zeolite, being present in a form of α-Fe nanoparticles with good catalytic properties. The supported catalyst samples were characterized structurally and morphologically. Benzene was selected to represent the organic contamination in these experiments. Fixed bed experiments were conducted using a vertical glass column. A saturated aqueous benzene solution (22.5 mM) was continuously pumped (0.5 ml/min) into the column simultaneously with the amount of H₂O₂ (30 %) necessary (12.5 ml) for the reaction in up flow mode. The pH was fixed at 3–4 with a buffer solution. All experiments were performed at 20 °C. The hydraulic retention time of benzene inside the column was estimated in 40 min. Benzene degradation, in the presented experimental conditions, is near 80 % and the process shows good stability for at least 600 min. Neither Fe(II) nor Fe(III) is detected in the eluded solution. This novel heterogeneous catalyst was demonstrated as a potent Fenton catalyst which provided an attractive alternative for the treatment of organic pollutants in water/wastewater.