Laser-induced Damage of Multilayer Oxide Coatings at 248 nm

Chaoyang Wei,Hongbo He,Hongji Qi,Kui Yi,Zhengxiu Fan 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.58 No.42

Al_2O_3/SiO_2 and HfO_2/SiO_2 high reflection coatings for 248 nm were deposited with optimized parameters to try to elucidate the laser-induced damage mechanisms of oxide coatings for 248 nm irradiation. Qualitative differences in the laser-induced damage thresholds (LIDTs) and in the surface morphologies indicated that the dominant damage mechanisms were different for the two multilayers. The damage morphology information showed that the damage was induced by defects for the HfO_2/SiO_2 multilayers whereas the damage for Al_2O_3/SiO_2 multilayers displayed intrinsic damage characteristics that were dramatically different from those of HfO_2/SiO_2 multilayers. Quantitative analyse of the above two kinds of coatings were done. The results showed that the damage to the HfO_2/SiO_2 multilayers can be well explained by a defect model. As for the damage to the Al_2O_3/SiO_2 multilayer, a quantitative analysis based on electron production via multiphoton ionization (MPI) and impact ionization (II) was in good agreement with the assumption that the damage to the Al_2O_3/SiO_2 multilayers was induced by intrinsic nonlinear absorption.

Influence of axial clearance on the performance characteristics of a turbopump

Deyou Li,Zhipeng Ren,Rong Fan,Yafei Chai,Ruzhi Gong,Hongjie Wang 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.10

To evaluate the influence of axial clearance on the performance characteristics in turbopumps, numerical simulations of an entire flow passage were carried out. The simulations were validated by performance characteristic experiments. The progress of the reciprocating axial movement in the rotor between the front and back covers was disassembled into five fixed clearances groups. Hump characteristic occurs at the same flow rate under these clearances groups. The hydraulic loss of the inducer-impeller was clearly influenced by the clearances. In particular, the hydraulic loss of the impeller changes significantly at the low flow rate under the ±0.3 mm clearance. With the increase of the flow rate, the effect of the clearance change on the flow is weakened. An innovative entropy production analysis was also performed. The distribution of the high local entropy production rate at the impeller inlet under the 0 mm clearance and at the impeller outlet under the −0.15 mm and −0.3 mm clearances overlapped with the vortex caused by flow separation, and the counterpart at the back cover is concentrated around the clearance structures, thereby leading to high hydraulic loss.

Construction and Immunogenicity of Recombinant Swinepox Virus Expressing Outer Membrane Protein L of Salmonella

( Yizhen Fang ),( Huixing Lin ),( Zhe Ma ),( Hongjie Fan ) 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.6

Salmonella spp. are gram-negative flagellated bacteria that cause a variety of diseases in humans and animals, ranging from mild gastroenteritis to severe systemic infection. To explore development of a potent vaccine against Salmonella infections, the gene encoding outer membrane protein L (ompL) was inserted into the swinepox virus (SPV) genome by homologous recombination. PCR, western blot, and immunofluorescence assays were used to verify the recombinant swinepox virus rSPV-OmpL. The immune responses and protection efficacy of rSPV-OmpL were assessed in a mouse model. Forty mice were assigned to four groups, which were immunized with rSPV-OmpL, inactive Salmonella (positive control), wildtype SPV (wtSPV; negative control), or PBS (challenge control), respectively. The OmpLspecific antibody in the rSPV-OmpL-immunized group increased dramatically and continuously over time post-vaccination, and was present at a significantly higher level than in the positive control group (p < 0.05). The concentrations of IFN-γ and IL-4, which represent Th1-type and Th2-type cytokine responses, were significantly higher (p < 0.05) in the rSPVOmpL- vaccinated group than in the other three groups. After intraperitoneal challenge with a lethal dose of Salmonella typhimurium CVCC542, eight out of ten mice in the rSPV-OmpLvaccinated group were protected, whereas all the mice in the negative control and challenge control groups died within 3 days. Passive immune protection assays showed that hyperimmune sera against OmpL could provide mice with effective protection against challenge from S. typhimurium. The recombinant swinepox virus rSPV-OmpL might serve as a promising vaccine against Salmonella infection.

Construction and Immunogenicity of Recombinant Swinepox Virus Expressing Outer Membrane Protein L of Salmonella

Fang, Yizhen,Lin, Huixing,Ma, Zhe,Fan, Hongjie The Korean Society for Microbiology and Biotechnol 2016 Journal of microbiology and biotechnology Vol.26 No.7

Salmonella spp. are gram-negative flagellated bacteria that cause a variety of diseases in humans and animals, ranging from mild gastroenteritis to severe systemic infection. To explore development of a potent vaccine against Salmonella infections, the gene encoding outer membrane protein L (ompL) was inserted into the swinepox virus (SPV) genome by homologous recombination. PCR, western blot, and immunofluorescence assays were used to verify the recombinant swinepox virus rSPV-OmpL. The immune responses and protection efficacy of rSPV-OmpL were assessed in a mouse model. Forty mice were assigned to four groups, which were immunized with rSPV-OmpL, inactive Salmonella (positive control), wild-type SPV (wtSPV; negative control), or PBS (challenge control), respectively. The OmpL-specific antibody in the rSPV-OmpL-immunized group increased dramatically and continuously over time post-vaccination, and was present at a significantly higher level than in the positive control group (p < 0.05). The concentrations of IFN-γ and IL-4, which represent Th1-type and Th2-type cytokine responses, were significantly higher (p < 0.05) in the rSPV-OmpL-vaccinated group than in the other three groups. After intraperitoneal challenge with a lethal dose of Salmonella typhimurium CVCC542, eight out of ten mice in the rSPV-OmpL-vaccinated group were protected, whereas all the mice in the negative control and challenge control groups died within 3 days. Passive immune protection assays showed that hyperimmune sera against OmpL could provide mice with effective protection against challenge from S. typhimurium. The recombinant swinepox virus rSPV-OmpL might serve as a promising vaccine against Salmonella infection.

The Identification of Six Novel Proteins with Fibronectin or Collagen Type І Binding Activity from Streptococcus suis Serotype 2

Hui Zhang,Junxi Zheng,Li Yi,Yue Li,Zhe Ma,Hongjie Fan,Chengping Lu 한국미생물학회 2014 The journal of microbiology Vol.52 No.11

Streptococcus suis, a major swine pathogen, is an emergingzoonotic agent that causes meningitis and septic shock. Bacterialcell wall and secreted proteins are often involved ininteractions with extracellular matrix proteins (ECMs), whichplay important roles in the initial steps of pathogenesis. Inthis study, 2D SDS-PAGE, western blotting-based bindingaffinity measurements, and microtiter plate binding assayswere used to identify cell wall and secreted proteins from S. suis that interact with fibronectin and collagen type І. Weidentified six proteins from S. suis, including three proteins(translation elongation factor G, oligopeptide-binding proteinOppA precursor, and phosphoglycerate mutase) thatshow both fibronectin and collagen type І binding activity. To the best of our knowledge, these three newly identifiedproteins had no previously reported fibronectin or collagentype І binding activity. Overall, the aim in this study was toidentify proteins with ECM binding activity from S. suis andit represents the first report of six new proteins from S. suisthat interact with fibronectin or collagen type І.