http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Kinetics of microbial hydrogenation of free linoleic acid to conjugated linoleic acids
Xu, H.,Lee, H.Y.,Hwang, B.,Nam, J.H.,Kang, H.Y.,Ahn, J. Blackwell Publishing Ltd 2008 Journal of applied microbiology Vol.105 No.6
<P>Abstract</P><P>Aims: </P><P>To investigate the ability of selected probiotic bacterial strains to produce conjugated linoleic acid (CLA) and also to estimate the biohydrogenation kinetics of <I>Lactobacillus acidophilus</I> on the production of CLA from free linoleic acid (LA).</P><P>Methods and Results: </P><P>Six probiotic bacteria, <I>Lact</I>. <I>paracasei</I>, <I>Lact</I>. <I>rhamnosus</I> GG, <I>Lact</I>. <I>acidophilus</I> ADH, and <I>Bifidobacterium longum</I> B6, <I>Lact</I>. <I>brevis</I>, and <I>Lact</I>. <I>casei</I>, were used to examine their ability to convert LA to CLA. LA tolerance was evaluated by addition of different LA concentrations in MRS broth. <I>Lact</I>. <I>acidophilus</I> showed the major tolerant to LA and the greatest CLA-producing ability (36–48 &mgr;g ml<SUP>−1</SUP> of CLA). The rate-controlling steps were <I>k</I><SUB>2</SUB> and <I>k</I><SUB>1</SUB> for the addition of 1 and 3 mg ml<SUP>−1</SUP> of LA, respectively. The percentage of CLA conversion was higher in MRS broth supplemented with 1 mg ml<SUP>−1</SUP> (65%) than 3 mg ml<SUP>−1</SUP> (26%).</P><P>Conclusion: </P><P>The results provide useful information and new approach for understanding the biohydrogenation mechanisms of CLA production.</P><P>Significance and Impact of the Study: </P><P>This study would help elucidate the pathway from LA to stearic acid (SA), known as biohydrogenation. In addition, the use of selected probiotic bacteria might lead to a significant improvement in food safety.</P>
R. F. Xu,K. Li,G. H. Chen,B. Y. Z. Qiang,D. L. Mo,B. Fan,C. C. Li,M. Yu,M. J. Zhu,T. A. Xiong,B. Liu 아세아·태평양축산학회 2005 Animal Bioscience Vol.18 No.7
New polymorphism of major histocompatibility complex B-G genes was investigated by amplification and digestion of a 401bp fragment including intron 1 and exon 2 using polymerase chain reaction-restriction fragment length polymorphism (PCRRFLP) technique with two restriction enzymes of Msp I and Tas I in eight breeds of Chinese indigenous chickens and one exotic breed. In the fragment region of the gene, three novel single nucleotide polymorphisms (SNPs) were detected at the two restriction sites. We found the transition of two nucleotides of A294G and T295C occurred at Tas I restriction site, and consequently led to a nonsynonymous substitution of asparagine into serine at position 54 within the deduced amino acid sequence of immunoglobulin variableregion- like domain encoded by the exon 2 of B-G gene. It was observed at rare frequency that a single mutation of A294G occurring at the site, also caused an identical substitution of amino acid, asparagine 54-to-serine, to that we described previously. And the transversion of G319C at Msp I site led to a non-synonymous substitution, glutamine 62-to-histidine. The new alleles and allele frequencies identified by the PCR-RFLP method with the two enzymes were characterized, of which the allele A and B frequencies at Msp I and Tas I loci were given disequilibrium distribution either in the eight Chinese local breeds or in the exotic breed. By comparison, allele A at Msp I locus tended to be dominant, while, the allele B at Tas I locus tended to be dominant in all of the breeds analyzed. In Tibetan chickens, the preliminary association analysis revealed that no significant difference was observed between the different genotypes identified at the Msp I and Tas I loci and the laying performance traits, respectively.
( H S Xu1 ),( D B Sun ),( H Y Yu ),( H M Meng ) 한국부식방식학회(구 한국부식학회) 2015 Corrosion Science and Technology Vol.14 No.6
The capacity of passive metal to repassivate after film damage determines the development of local corrosion and the resistance to corrosion failures. In this work, the repassivation kinetics of 316L stainless steel (316LSS) was investigated in borate buffer solution (pH 9. 1) using a novel abrading electrode technique. The repassivation kinetics was analyzed in terms of the current density flowing from freshly bare 316L SS surface as measured by a potentiostatic method. During the early phase of decay (t < 2 s), according to the Avrami kinetics-based film growth model, the transient current was separated into anodic dissolution (idiss) and film formation (ifilm) components and analyzed individually. The film reformation rate and thickness were compared according to applied potential. Anodic dissolution initially dominated the repassivation for a short time, and the amount of dissolution increased with increasing applied potential in the passive region. Film growth at higher potentials occurred more rapidly compared to at lower potentials. Increasing the applied potential from 0 VSCE to 0. 8 VSCE resulted in a thicker passive film (0. 12 to 0. 52 nm). If the oxide monolayer covered the entire bare surface (θ=1), the electric field strength through the thin passive film reached 1. 6 × 107 V/cm.
AUTOMOTIVE WINDSHIELD - PEDESTRIAN HEAD IMPACT: ENERGY ABSORPTION CAPABILITY OF INTERLAYER MATERIAL
Xu, J.,Li, Y.B.,Chen, X.,Ge, D.Y.,Liu, B.H.,Zhu, M.Y.,Park, T.H. 한국자동차공학회 2011 International journal of automotive technology Vol.12 No.5
During accident, the interlayer of windshield plays an important role in the crash safety of automotive and protection of pedestrian or passenger. The understanding of its energy absorption capability is of fundamental importance. Conventional interlayer material of automotive windshield is made by Polyvinyl butyral (PVB). Recently, a new candidate of high-performance nanoporous energy absorption system (NEAS) has been suggested as a candidate for crashworthiness. For the model problem of pedestrian head impact with windshield, we compare the energy absorption capabilities of PVB and NEAS interlayers, in terms of the contact force, acceleration, velocity, head injury criteria, and energy absorption ratio, among which results obtained from PVB interlayers are validated by literature references. The impact speed is obtained from virtual test field in PC-CRASH, and the impact simulations are carried out using explicit finite element simulations. Both the accident speed and interlayer thickness are varied to explore their effects. The explicit relationships established among the energy absorption capabilities, impact speed, and interlayer material/thickness, are useful for safety evaluation as well as automotive design. It is shown that the NEAS interlayer may absorb more energy than PVB interlayer and it may be a competitive candidate for windshield interlayer.
XU B. Y.,LIANG F. Y.,CAI S. L.,QI Y. L. The Korean Society of Automotive Engineers 2005 International journal of automotive technology Vol.6 No.6
Unsteady state free natural gas jets injected from several types of injectors were numerically simulated. Simulations showed good agreements with the schlieren experimental results. Moreover, injections of natural gas in intake manifolds of a single-valve engine and a double-valve engine were predicted as well. Predictions revealed that large volumetric injections of natural gas in intake manifolds led to strong impingement of natural gas with the intake valves, which as a result, gave rise to pronounced backward reflection of natural gas towards the inlets of intake manifolds, together with significant increase in pressure in intake manifold. Based on our simulations, we speculated that for engines with short intake manifolds, reflections of the mixture of natural gas and air were likely to approach the inlets of intake manifolds and subsequently be inbreathed into other cylinders, resulting in non-uniform mixture distributions between the cylinders. For engines with long intake manifolds, inasmuch as the degrees of intake interferences between the cylinders were not identical in light of the ignition sequences, non-uniform intake charge distributions between the cylinders would occur.
NUMERICAL ANALYSIS OF HOMOGENEOUS MIXTURE FORMATION FOR A DIRECT INJECTION LIQUID LPG ENGINE
B. Y. XU,X. C. ZHANG,J. XU,Y. L. QI,S. L. CAI 한국자동차공학회 2013 International journal of automotive technology Vol.14 No.6
A method to form a homogeneous mixture using low pressure direct injection of liquid phase LPG, pent-roof combustion chamber, flat-top piston and center-located injector layout is presented. To validate the method, the mixture formation processes in the cylinder were investigated using the CFD code. The effect of different injection timing and engine loads on the mixture formation processes were researched. The simulated results showed that, the intake tumble for high load conditions or the inclined intake swirl for part load conditions would break into small-scale vortex (turbulence) near the end of compression stroke, which enhanced the homogeneous mixture formation. The results also showed that if the liquid phase LPG was injected at 60-80oCA ATDC in intake stroke even at different loads, the homogeneous mixture would be formed under any engine load conditions.
FUEL PROPERTIES AND EMISSIONS CHARACTERISTICS OF ETHANOL-DIESEL BLEND ON SMALL DIESEL ENGINE
Xu, B.Y.,Qi, Y.L.,Zhang, W.B.,Cai, S.L. The Korean Society of Automotive Engineers 2007 International journal of automotive technology Vol.8 No.1
Phase separation and low cetane number are the main barriers to the large-scale use of ethanol-diesel blend fuel on small diesel engines. In this paper, an additive package is designed on the basis of the blended fuel properties to overcome these limitations. The experiments show that the solubility of ethanol in diesel is evidently increased by adding $1{\sim}2%$ (in volume) of the additive package and the flammability of ethanol-diesel blend fuel with the additive has reached the neat diesel level under the cold start conditions. Effects of the ethanol content in diesel on fuel economy, combustion characteristics, and emission characteristics are also investigated with the ethanol blend ratios of 10%, 20% and 30%. The increase in ethanol content shows that the specific fuel consumption and the brake thermal efficiency are both gradually increased compared to neat diesel. The soot concentrations of the three blended fuels are all greatly lower than that of neat diesel. $NO_x$ emission is increased with an increase in the engine load and is reduced with the increase in the ethanol blend ratio under a high load.