Analysis of 2,4,6-trinitrotoluene, pentaerythritol tetranitrate and cyclo-1,3,5-trimethylene-2,4,6-trinitramine using negative corona discharge ion mobility spectrometry

In this study, the capability of negative corona discharge ion mobility spectrometry (IMS) for quantitative magnitude of several explosives including 2,4,6-trinitrotoluene (TNT), pentaerythritol tetranitrate (PETN) and cyclo-1,3,5-trimethylene-2,4,6-trinitramine (RDX) has been evaluated for the first time. The total current obtained with the negative corona discharge was about 100 times larger than that of IMS based on ⁶³Ni, which results in a lower detection limit and a wider linear dynamic range. The detection limits for PETN, TNT and RDX were 8×10⁻¹¹, 7×10⁻¹¹ and 3×10⁻¹⁰ g, respectively. The calibration plots for these explosives showed linear dynamic ranges of about four orders of magnitude.     

Uneven Dielectric Barrier Discharge Reactors for Diesel Particulate Matter Removal

Uneven dielectric barrier discharge (DBD) reactors driven by positive–negative pulse plasma discharges were investigated for particulate matter (PM) removal from a diesel engine. Two kinds of uneven alumina plates and three kinds of uneven stainless steel plates were used to assemble six kinds of uneven DBD reactors of discharge gaps 0.4–1.0 mm. The experimental results show that PM from diesel engines can be removed using the uneven DBD reactors. The maximum PM removal was 67% at 300 W energy injections using the DBD reactor of 0.4 mm gap distance. PM removal increased with decreasing gap distance. The energy efficiency using the uneven DBD reactor of a shorter gap distance was higher than that using the uneven DBD reactor of a longer gap distance as the uneven DBD reactor of a shorter gap distance has a higher PM deposition rate. The energy efficiency was typically in a range of 3–10.6 g/kWh at an energy density of 2–16 J/L. A comparison of this study with reports given by other research groups is given.     

Comparative Study of the Decomposition of CCl4 in Cold and Thermal Plasma

Decomposition of carbon tetrachloride was studied in an inductively coupled thermal plasma reactor and in a low temperature, non-equilibrium plasma reactor, in neutral and oxidative conditions, respectively. In neutral conditions formation of solid soot, aliphatic- and cyclodienes was observed in equilibrium, and products, such as Cl₂ and C₂Cl₆ were detected in non-equilibrium plasma. Feeding of oxygen into the thermal plasma reactor depressed both soot and dienes formation and induced the formation of oxygen containing intermediates and products. GC-MS analyses of the gaseous products and the extract of the soot referred to as complex decomposition and recombination mechanism at given conditions. Presence of oxygen in the low temperature plasma reactor results in the formation of carbonyl compounds as intermediers. CO₂ and Cl₂ revealed as final products of CCl₄ decomposition in cold plasma.     

潮湿空气微波放电离子形成动力学

利用微波放电电离质谱装置，通过水蒸气与空气混合气体（潮湿空气）的微波放电，同时获得了化学电离质谱探测技术中常用的三种重要母体离子H3O＋、NO＋和.结合潮湿空气中主要成分N2、O2以及水蒸气各自微波放电后的质谱探测结果，对潮湿空气微波放电后上述三种离子产生的动力学过程进行了分析，并给出了各种离子的形成机制.这些离子 分子反应过程在计算机模拟中得到了进一步的证实.     

抛物线形渠道长喉道测流槽的水力设计方法

根据边界层理论和临界水深理论，提出了抛物线形长喉道测流槽的水力设计方法及流量计算公式，并用具体算例说明了设计步骤。该设计方法可以灵活地改变抛物线形测流槽的形状参数，不需要试验率定，且计算简单、精度高。     

介质阻挡放电系统中不同对称性斑图的演化

利用双水电极实验装置,在介质阻挡放电系统中观察到了具有不同空间对称性的斑图之间的演化过程.在实验中,通过改变外界驱动电压发现:在升高电压的过程中,条纹斑图会发生失稳,并逐渐形成六边形斑图;形成规则的六边形斑图后,降低驱动电压,六边形斑图会失稳再次形成条纹结构.进一步降低驱动电压,在条纹斑图中观察到了横向调制失稳现象.     

介质阻挡放电脱除气态环己酮的研究

利用介质阻挡放电反应器进行了脱除挥发性有机物废气——环己酮的研究.通过改变极间电压,所加频率等条件,考察这些因素对环己酮脱除率的影响.通过研究发现:环己酮的脱除率随着极间电压,所加频率的升高而增加.当环己酮初始浓度为100 mL/m3,极间电压9 000 V时,环己酮的脱除率达到92.7%,证明介质阻挡放电对于流动态中的环己酮有很好的脱除效果.同时通过对反应过程中发射光谱的观察,对介质阻挡放电等离子体脱除环己酮的机理进行了初步的探讨.     

混合气体放电中等离子体发射光谱诊断

采用水电极介质阻挡放电装置,分别在氮气/氩气、空气/氩气2种混合气体放电中,采用光谱的方法测量了氮分子(C3Πu)和氮分子离子391.4 nm(B2Σu+→X2Σg+)谱线随混合气体的体积分数的变化.实验表明:随混合气体中氩气体积分数的增加,氮分子(C3Πu)的谱线强度增强,而氮分子离子391.4 nm谱线强度减弱;在2种混合气体中、相同的氩气体积分数下,氮气/氩气混合气体放电时的氮分子(C3Πu)和氮分子离子391.4 nm(B2Σu+→X2Σg+)发射谱线强度比空气/氩气混合气体放电时的强.     

介质阻挡放电中的六边形与四边形混合结构

采用特殊的水电极介质阻挡放电实验装置,首次在空气介质阻挡放电中得到了六边形斑图、四边形斑图及它们的混合结构.分析了六边形斑图中晶轴的取向与缺陷对的特性.通过图像的相关运算得到了这种混合结构中六边形的空间位置分布.     

气体成分对介质阻挡放电中超四边形斑图的影响

采用介质阻挡放电装置,研究了1.01×105Pa下空气和氩气的混合气体中气体成分对超四边形斑图的影响.实验发现,随着空气体积分数的增大,产生超四边形斑图所需要的驱动电压也随之升高,同时,超四边形斑图越来越不稳定,放电丝直径逐渐变小,当空气体积分数大于4%时放电丝个数由每行6个增加到7个.