多孔介质中轻非水相液体挥发过程的电阻率成像法监测

在含有细砂透镜体的三维非均质砂槽中进行了轻非水相液体(LNAPLs)的挥发实验,并应用电阻率成像法进行同步动态监测,尝试通过电阻率图像的变化反映砂槽中LNAPLs的挥发过程。结果表明,砂槽注油后电阻率明显上升,LNAPLs污染中心区域的电阻率大于边缘区域,由上往下电阻率减小,其图像近似半球形。注油结束后,污染物逐渐挥发,污染区域LNAPLs浓度不断减小,表现为电阻率逐渐降低。监测过程表明,应用电阻率成像法监测LNAPLs挥发过程是有效的。

双主剂型改性丙烯酸酯结构胶挥发过程的质量变化研究

在定温、定压和定湿度条件下,用电子天平对双主剂型改性丙烯酸酯结构胶(AB胶)挥发过程中质量随时间的变化进行了测量研究.实验结果分析表明,AB胶的A和B组分的挥发都包含一快一慢两个过程,对应于两个挥发过程,至少有两种易挥发的单质,而且A组分中它们的含量分别大于18.4%和28.9%,B组分中它们的含量分别大于13.6%和34.7%.AB混合物的挥发只有一个过程,仅存在一种主要易挥发物,其含量至少大于16.1%.根据丙烯酸酯胶固化反应机理,可以认为在A、B组分中存在的易挥发物质分别为甲基丙烯酸和甲基丙烯酸甲酯,而AB混合物的质量变化主要由甲基丙烯酸的挥发所致.

丙烯酸酯结构胶粘剂的挥发过程的热分析研究

通过同步热分析仪,测量了在恒温条件下丙烯酸酯结构胶粘剂(AB胶)的A和B组分的热量、温度、质量随时间的变化.结果表明:1)A和B组分都具有明显的挥发性,挥发先快后慢,挥发量接近40%,挥发物质为两种或两种以上,而且A比B组分挥发得更快;2)在A和B组分的挥发过程中伴有热量的吸收,速率随时间快速减小,约10min后吸热过程变得缓慢,A和B组分在实验过程中吸收的热量Q分别为261.6J/g和163.3J/g;3)整个测量过程中,A和B组分的温度变化都较小,约在0.5℃的范围内.

空气辅助挥发冷凝过程分离环己烷-乙醇

提出了空气辅助挥发冷凝过程分离共沸物的新方法,以共沸物环己烷-乙醇为研究对象,考察了新分离方法的分离效果。实验结果表明,在两种不同的原料组成下所得产品全部突破了共沸组成。与水萃取法相比,空气辅助挥发冷凝法分离环己烷-乙醇具有不形成新的共沸物的优点。

油船油气挥发的危害与处理措施的研究

通过对油船油气挥发过程及油气危害的描述,以及目前国内油船现状和设置油气回收设施必要性的分析,结果表明应该从建立相关的国家标准、改造油船和码头设施入手,减少和避免油气对健康、环境、安全带来的影响。

草坪生态系统中氨挥发研究进展(综述)

概述了草坪生态系统氨挥发的研究成果,主要从氨挥发过程、影响因素、测定方法和减少挥发的途径等方面进行综述,为草坪合理有效地施肥提供依据。

水性涂料中成膜助剂的应用与发展方向

从乳胶漆的成膜过程出发,揭示了成膜助剂的作用机理,研究了成膜助剂的分类及其在不同阶段的挥发过程,并介绍了成膜助剂的特性及选择方法,最后对成膜助剂的发展方向进行了展望。

Study of Biofilm Formed by Lactic Acid Bacteria on the Surface of Mild Steel

Biocorrosion processes at metal surfaces are associated with microorganisms, or the products of their metabolic activities including enzymes, exopolymers, organic and inorganic acids, as well as volatile compounds such as ammonia or hydrogen sulfde. It was proved that strain Lactobacillus delbrueckii B5 constituted biofilms in the presence of different amounts of carbohydrates （5% sucrose and a mixture of 5% lactose, 5% fructose and 5% maltose）. The obtained information was used in a study treating the anticorrosive properties of microbial biofilms synthesized by the latter strain. The study of the corrosive stability of steel samples was conducted on the gravimetrique method. The rate of corrosion, calculated. The structure of layer over steel plates was analyzed by the degree of protection, and coefficient of protection has been Scanning Electron Microscopy （SEM） JSM 5510.

Process Intensification of VOC Removal from High Viscous Media by Rotating Packed Bed

The removal of a volatile organic compound (VOC) from high viscous liquid was carried out in a rotat-ing packed bed (RPB) in this study. The mixed liquid of syrup and acetone was used as simulated high viscous polymer solution with acetone as the volatile compound. The influence of the rotating speed of RPB, liquid viscos-ity, liquid flow rate, vacuum degree, and initial acetone content in the liquid on acetone removal efficiency was in-vestigated. The experimental results indicated that the removal efficiency increased with increasing rotating speed and initial acetone content in the viscous liquid and decreased with increasing liquid viscosity and flow rate. It was also observed that acetone removal efficiency increased with an increasing vacuum degree and reached 58% at a vacuum degree of 0.1 MPa. By the comparison with a flash tank devolatilizer, it was found that acetone removal ef-ficiency in RPB increased by about 67%.

Composition of Trans-anethol and Other Aromatic Volatiles in Anisated Alcoholic Beverages by Head-Space GC-MS Chromatography

Aniseed distillates, like ouzo in Greece, raki in Turkey, pastis in France, and arak in Syria, are very popular in Mediterranean countries. This flavoured alcoholic beverage is produced by extraction and distillation of fermented grape pomaces with herbal seeds from aromatic plants like Pimpinella anisum L., Foeniculum vulgate, Illicium verum and other plants which are also characterized by the presence of congeners which arise during fermentation process. Trans-anethol and its isomer cis-anethol are the main volatiles and are responsible for aroma properties of these traditional aniseed distillates. The aim of this research work was to find the concentration of special aromatic agent, trans-anethol and cis-anethol and also the major aromatic substances which are responsible for the aromatic quality. The majority of their identified components are isolated by extraction and distillation from different commercial brands and homemade samples. The constituents were identified by GC-MS （gas chromatography-mass spectometry） in this traditional spirit. The major constituents in distilled ouzo extract were also trans-anethol.

Using a Two-Liquid-Phase System to Investigate the Biodegradation of Trichlorobenzenes

Due to easy volatilization of volatile organic compounds from water,it is difficult to monitor their aerobic biodegradation in the traditional single water system.Whether a two-liquid-phase system(TLPS) could overcome this obstacle and enhance the degradation of volatile contaminants? In this study,a TLPS composed of silicone oil and water was employed to investigate the biodegradation of volatile compounds,trichlorobenzenes(TCBs),by the adapted microorganisms in an activated soil.The degradation and volatilization of TCBs in TLPS and in a single water system were compared.The results showed that due to volatilization losses of TCBs,the mass balance of TCBs in a single water system was very low.In contrast,using TLPS could effectively inhibit the volatilization losses of TCBs and achieved a very good mass balance during the biodegradation process.Meanwhile,the TLPS could increase microbial activity and microbial growth during the degradation process.With TLPS,the TCB degradation was in descending order of 1,2,4-TCB> 1,2,3-TCB>> 1,3,5-TCB,which was related to the exposed concentration of the contaminants in soil.This study showed that TLPS could be employed as an effective tool to evaluate the biodegradation of volatile hydrophobic organic compounds,which could not be achieved with the traditional single water system.

Experimental simulation of the relative contribution of volatile-N and char-N to NO_X formation from a low-capacity bituminous coal-fired industrial boiler

The conversion of fuel-N to NOx is the main contribution of modelling problem arising from coal combustion. This paper NOx from coal-fired industrial boilers and is the least-studied summarises the current understanding of the mechanisms that account for the formation of NOx from fuel-N during coal combustion. Further experimentation on NOx emissions during bi- tuminous coal combustion was simulated with attention focused on the contribution of char-N and votatile-N to fuel-NOx through the Coal/Char combustion method. The critical analysis of this issue allowed for the identification of uncertainties and produced well-founded conclusions. The results indicated that fuel-NOx formation was a very complex physical-chemical pro- cess involving many competing mechanisms. These mechanisms included chemical reactions, convective mass transfer, heat transfer, adsorption and desorption. The contribution of char-N in this experiment varied between 30% and 70%. There may be a slight question as to the exact identity of the main contributor to fuel-NOx, and no definitive conclusion can be made as of yet This uncertainty is because the contribution of char-N to fuel-NOx was heavily affected by the combustion conditions and the contribution of char-N increased monotonically as temperature increased. There was a critical point in the relationship between particle size, air flow, 02 concentration and the contribution of char-N. The contribution of char-N increased with the increase of particle size and air flow initially when less than the critical value, and decreased when more than thecritical value. The contribution of char-N initially decreased when the 02 concentration was increased from 10% to 15% and increased more with the further increase in 02 concentration.

The effect of volatile components in oil on evolutionary character- istics of diamondoids during oil thermal pyrolysis

On the basis of the results of simulation experiments, now we better understand the contribution of high carbon number hydrocarbons to diamondoid generation during thermal pyrolysis of crude oil and its sub-fractions(saturated, aromatic, resin, and asphalene fractions). However, little is known about the effect of volatile components in oil on diamondoid generation and diamondoid indices due to the lack of attention to these components in experiments. In this study, the effect of volatile components in oil on diamondoid generation and maturity indices was investigated by the pyrolysis simulation experiments on a normal crude oil from the HD23 well of the Tarim Basin and its residual oil after artificial volatilization, combined with quantitative analysis of diamondoids. The results indicate that the volatile components(≤n C12) in oil have an obvious contribution to the generation of adamantanes, which occurs mainly in the early stage of oil cracking(Easy Ro<1.0%), and influences the variations in maturity indices of adamantanes; but they have no obvious effect on the generation and maturity indices of diamantanes. Therefore, some secondary alterations e.g., migration, gas washing, and biodegradation, which may result in the loss of light hydrocarbons in oil under actual geological conditions, could affect the identification of adamantanes generated during the late-stage cracking of crude oil, and further influence the practical application of adamantane indices.