高效液相色谱(HPLC)在火灾原因鉴定中的应用

介绍了利用高效液相色谱鉴定汽油、煤油、柴油等石油系列为基质的常见助燃剂的分析方法。模拟火灾现场制备上述助燃剂的新鲜、挥发、过火、燃烧烟尘以及常见干扰物燃烧样品 ,并对其进行了分析研究     

Biosynthesis of essential oils in aromatic plants: A review

In aromatic plants species, biosynthesis of essential oils occurs through two complex natural biochemical pathways involving different enzymatic reactions. Isopentenyl diphosphate (IPP) and its isomer dimethylallyl diphosphate (DMAPP) are the universal precursors of essential oil biosynthesis and are produced by the cytosolic enzymatic MVA (mevalonic acid) pathway or by plastidic and enzymatic 1-deoxy-d-xylolose-5-phosphate (DXP) pathway, also called the 2-C-methylerythritol-4-phosphate (MEP) pathway. In the particular plant cell part, prenyl diphosphate synthases condense isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP) further to form prenyl diphosphates, which are used as substrates for geranyl diphosphate (GPP; C₁₀) or for fernesyl diphosphate (FPP; C₁₅). Essential oils are final terpenoid products and are formed by a huge group of enzymes known as terpene synthases (TPS). Essential oils are important secondary metabolites of plants and have been used not only in different industries but also in ethnobotanical medicines for centuries. Hence, considerable research has been undertaken to understand the essential oil biosynthetic pathways. This review will be a valuable source of information in the field of natural products, as we give detailed insights about biosynthesis of essential oils in plants and thus indicate also new unexplored horizons for further research.     

石油产品芳烃含量在线紫外分析仪的研制

研制了一种可用于石油产品中芳烃含量在线检测的紫外分析仪,仪器采用凹面全息光栅双单色仪和独特的进样系统,可保证吸光度高达7Abs的润滑油样品在石油生产现场不经稀释即可进行在线分析检测。经五年多工业现场使用,准确率达95%,无故障运行率达97%以上。为润滑油生产过程质量监测、优化操作,为光谱技术在石化工业应用开辟了一条新路。     

色谱法测定烷烃和芳烃在高碳烷烃中的亨利系数

用气相色谱法测定了５０－１００℃下烷烃和芳烃分别在正十六烷、正十七烷、正二十烷、正二十四烷、正三十烷中的亨利系数考虑了固定液流失量和上非理想性的校正。讨论了亨利系数Ｈ与溶质碳数和溶剂碳数之间的关系。结果证明：亨利系数随着溶碳数和溶剂碳数的增加而减少。     

芳纶电缆水下电连接器密封技术研究

芳纶电缆是一种新型电缆,具有质轻、强度高等优点,但常因连接密封技术问题影响其使用。本文介绍了芳纶电缆连接器的密封结构及设计和制造中的关键技术。地连接的可靠性和水密性进行了分析及试验,并提供了设计方法和腾技术参数。     

Optimizing Ni–Ce/HZSM-5 catalysts for ex-situ conversion of pine wood pyrolytic vapours into light aromatics and phenolic compounds

The main objective of the present work is to investigate the influence of nickel to cerium ratio on hydrogen exchanged Zeolite Socony Mobil-5 (HZSM-5) towards the catalytic upgrading of pine derived oxygenated pyrolysis vapours into aromatic hydrocarbon and phenol in pyrolysis oil via ex-situ fixed bed reactor. The presence of CeO₂ could change electron density of Ni, promote the reduction of Ni species, accelerate the transfer of carbon species, and suppress the production of carbon deposits (17.53%–25.11%) compared with the parent HZSM-5 catalyst (28.95%); it also improved the hydrodeoxygenation ability of all xNiyCe/HZSM-5(nickel and cerium bimetal modified HZSM-5) catalysts, resulting increases in noncondensable gas content (from 31.46% to 52.99%–65.53%). Ni to Ce ratio of 1:1 and 1:2 produced highest aromatic hydrocarbon (32.14%) and phenols (55.51%) relative peak areas. The acid center of HZSM-5 and the metal acid center of the Ni:Ce = 1:1 catalyst obviously fine-tuned the formation of coke; and promoted hydrocarbon production. Moreover, high Ni content promoted alkylation of benzene at C6–C9 and increased C10⁺ PAHs relative peak area; high Ce content promoted the formation of olefin and Increasing the cleavage of C–O bonds and promoted hydrogenation or dehydrogenation, reduced polycyclic aromatic hydrocarbons and coke yield, and increased phenols and alkylphenols selectivity.     

Potentiality of combined catalyst for high quality bio-oil production from catalytic pyrolysis of pinewood using an analytical Py-GC/MS and fixed bed reactor

The aim of this study was to investigate the potential of combined catalyst (ZSM-5 and CaO) for high quality bio-oil production from the catalytic pyrolysis of pinewood sawdust that was performed in Py-GC/MS and fixed bed reactor at 500 °C. In Py-GC/MS, the maximum yield of aromatic hydrocarbon was 36 wt% at biomass to combined catalyst ratio of 1:4 where the mass ratio of ZSM-5 to CaO in the combined catalyst was 4:1. An increasing trend of phenolic compounds was observed with an increasing amount of CaO, whereas the highest yield of phenolic compounds (31 wt%) was recorded at biomass to combined catalyst ratio of 1:4 (ZSM-5: CaO - 4:1). Large molecule compounds could be found to crack into small molecules over CaO and then undergo further reactions over zeolites. The water content, higher heating value, and acidity of bio-oil from the fixed bed reactor were 21%, 24.27 MJkg⁻¹, and 4.1, respectively, which indicates that the quality of obtained bio-oil meets the liquid biofuel standard ASTM D7544-12 for grade G biofuel. This research will provide a significant reference to produce a high-quality bio-oil from the catalytic pyrolysis of woody biomass over the combined catalyst at different mass ratios of biomass to catalyst.     

Modeling of an axial flow,spherical packed-bed reactor for naphtha reforming process in the presence of the catalyst deactivation

Improving the octane number of the aromatics’ compounds has always been an important matter in refineries and lots of investigations have been made concerning this issue. In this study, an axial-flow spherical packed-bed reactor (AF-SPBR) is considered for naphtha reforming process in the presence of catalyst deactivation. Model equations are solved by the orthogonal collocation method. The AF-SPBR results are compared with the plant data of a conventional tubular packed-bed reactor (TR). The effects of some important parameters such as pressure and temperature on aromatic and hydrogen production rates and catalyst activity have been investigated. Higher production rates of aromatics can successfully be achieved in this novel reactor. Moreover, results show the capability of flow augmentation in the proposed configuration in comparison with the TR. This study shows the superiority of AF-SPBR configuration to the conventional types.     

水合肼法还原芳香硝基化合物制备芳胺的技术进展

综述了水合肼法还原芳香硝基化合物制备芳胺及其衍生物的近况,讨论了影响还原反应的主要因素和工艺条件,并展望了水合肼法制备芳胺工艺的应用前景和发展方向。     

超高压处理对黑莓酒香气成分的影响

运用超高压技术处理黑莓酒以期改善其香气品质,并采用固相微萃取与气相色谱-质谱联用对不同超高压条件处理的黑莓酒挥发性香气成分进行检测,探究超高压处理对黑莓酒香气成分的影响及作用机理.结果表明:经超高压处理的黑莓酒香气种类与未处理样品相同,但含量发生较大变化,200MPa处理20min的黑莓酒醇类、酯类和醛类无显著变化(p＞0.05),酸类减少了7.44％;600MPa处理20min的黑莓酒醇类、酯类分别增加了4.63％、13.38％,醛类、酸类无显著变化(p＞0.05);400MPa处理20min的黑莓酒醇类、酯类和醛类分别增加了4.89％、43.04％和1.12％,酸类减少了11.28％,整体香气趋向柔和、协调、饱满,达到改善黑莓酒香气品质的目的.