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Ma C.,Nankai University | Ai C.,Lanzhou Petrochemical Research Center | Li Z.,Nankai University | Li B.,Nankai University | And 4 more authors.

The series of NHC-based cyclometalated ruthenium(II) complexes 2a-k were synthesized by the reactions of aryl-substituted imidazolium salts with [(p-cymene)RuCl2]2 under mild conditions. These complexes could react with alkynes in MeOH at 80 °C, through alkyne insertion and subsequent reductive elimination, to give the new kinds of imidazolium salts 3a-q in high yields. All new compounds were fully characterized, and the molecular structures of 2a-d,f,g,i-k were determined by single-crystal X-ray diffraction analysis. © 2014 American Chemical Society. Source

Zhou R.,Xian Jiaotong University | Zheng H.,Lanzhou Petrochemical Research Center | Zheng Y.,Xian Jiaotong University
Polymer Degradation and Stability

Reinforced nitrile-butadiene rubber by aramid fibers and polyacrylonitrile fibers was investigated as flexible ablative materials. Erosion resistance of the ablative materials reinforced by both fibers was greatly improved. Comparing to the physical reinforcement, confinement effect of fibers plays a more important role for the improved erosion resistance of the ablative materials. Four different layers, including virgin material, pyrolysis layer, loose carbon layer and dense carbon layer were formed inside the ablative materials during the pyrolysis process, and aligned gas channels were observed in the two carbon layers. The aligned gas channels were formed through the aid of fibers, and they facilitated the release of high pressure inside the composites as well as helped strengthen the pyrolysis gas flow discharged out of the ablative materials, which greatly contributed to the improved erosion resistance of the composite. © 2015 Elsevier Ltd. All rights reserved. Source

Qin P.,Lanzhou Petrochemical Research Center | Wang F.,Lanzhou Petrochemical Research Center | Fan G.,Lanzhou Petrochemical Research Center | Geng Z.,Lanzhou Petrochemical Research Center
Speciality Petrochemicals

The sulfides in straight-run diesel oil were separated and concentrated by silver nitrate coordination method and AgNO 3/silica gel column, respectively. GC-MS was used to identify the structure of the separated sulfides and GC-FPD was used to determine the concentration. The results showed that the silver nitrate coordination method can separate 50 kinds of sulfoethers in the straight-run diesel oil effectively, while silica gel column can separate more then 10 kinds of dibenzothiophene (DBT). Additionally, the sulfides in the straight diesel oil can be converted to the corresponding sulfone with strong polarity by using peroxyacid prepared with hydrogen peroxide and formic acid as oxidant. Establishment of this method has great significance for the analysis of the distribution of sulphides before and after the desulfurization process in straight-run diesel oxidation. Source

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