| 1. |
- Guo, Shilong, et al.
(author)
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Investigation on bluff-body and swirl stabilized flames near lean blowoff with PIV/PLIF measurements and LES modelling
- 2019
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In: Applied Thermal Engineering. - : Elsevier BV. - 1359-4311. ; 160
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Journal article (peer-reviewed)abstract
- Lean premixed combustion (LPC) is a promising technology for low-NOx emission, while it increases the risk of blowoff at the same time. Experiments and Large Eddy Simulations (LES) on swirl stratified lean-premixed CH4/air flames were performed to study the differences between the stable and near blowoff flame. The flow fields and instantaneous flame structures were measured by simultaneous Particle Image Velocimetry (PIV) and Planar Laser Induced Fluorescence (OH-PLIF). The Thickened Flame (TF) model coupled with a two-step reduced chemical mechanism was used in LES modelling. The non-dynamic formulation of sub-grid flame wrinkling model is performed well for stable condition while it cannot predict the near lean blowoff flame reasonable. Compared with the stable flame, several significant differences can be observed in the near lean blowoff flame. The height of high-temperature-zone is relatively low and the heat loss of flame attachment can be easily enhanced by the low temperature spot induced by flame-vortex interaction. The flame attachment is subject to higher excess strain rate and turbulence fluctuation. Meanwhile, a Processing Vortex Core (PVC) appears downstream of the centerline. It is concluded that lean blowoff is the result of interactions between the fuel/air mixture ignition, PVC instability and flame attachment lift-off.
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| 2. |
- Liu, Fei, et al.
(author)
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Draft genomes of four enterotoxigenic Escherichia coli (ETEC) clinical isolates from China and Bangladesh
- 2015
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In: Gut Pathogens. - : Springer Science and Business Media LLC. - 1757-4749. ; 7
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Journal article (peer-reviewed)abstract
- © 2015 Liu et al. Abstract Background: Enterotoxigenic Escherichia coli (ETEC) is an important pathogen that causes childhood and travelers' diarrhea. Here, we present the draft genomes of four ETEC isolates recovered from stool specimens of patients with diarrhea in Beijing, China and Dhaka, Bangladesh, respectively. Results: We obtained the draft genomes of ETEC strains CE516 and CE549 isolated in China, and E1777 and E2265 isolated in Bangladesh with a length of 5.1 Mbp, 4.9 Mbp, 5.1 Mbp, and 5.0 Mbp, respectively. Phylogenetic analysis indicated that the four strains grouped with the classical Escherichia coli phylogenetic groups A and B1 and three of them including a multi drug-resistant Chinese isolate (CE549) belonged to two major ETEC lineages distributed globally. The heat stable toxin (ST) structural gene (estA) was present in all strains except in strain CE516, and the heat labile toxin (LT) operon (eltAB) was present in all four genomes. Moreover, different resistance gene profiles were found between the ETEC strains. Conclusions: The draft genomes of the two isolates CE516 and CE549 represent the first genomes of ETEC reported from China. Though we revealed that ETEC is uncommon in Beijing, China, however, when it does occur, multi-drug resistance and ESBL positive isolates might pose a specific public health risk. Furthermore, this study advances our understanding of prevalence and antibiotic resistance of ETEC in China and adds to the number of sequenced strains from Bangladesh.
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| 3. |
- Sun, Yufu, et al.
(author)
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Effects of nickel on low-temperature impact toughness and corrosion resistanceof high-ductility ductile iron
- 2012
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In: Materials & design. - : Elsevier. - 0264-1275 .- 1873-4197 .- 0261-3069. ; 41, s. 37-42
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Journal article (peer-reviewed)abstract
- High-ductility ductile iron was alloyed with 0–1.8 wt% Ni in this paper. The low-temperature impact toughness test and corrosion test of simulated seawater static whole-soaking were conducted to research the effect of nickel on the low-temperature impact toughness and corrosion resistance of high-ductility ductile iron. The results show that with nickel increasing, the impact toughness under low temperature ascents a great deal, and reaches the highest point with 0.71 wt% nickel addition, then descents; while the corrosion resistance has always been growing with the increasing of nickel content. Ductile iron containing 0.71 wt% nickel shows the best low-temperature impact toughness (the impact toughness values Akv of the samples reached 16.6 J at 20 C, 12.8 J at 40 C respectively) and exhibits the optimum combination properties. The presence of rust layer, which was made up of Fe3O4, played certain barrier for electrochemical reaction.
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