The purposes of this study are to compare the proteome of Vibrio cholerae O139 strains with that of O22, O155 and El Tot biotype epidemic strains, and to identifv whether O139 strains have a close relation with the la...The purposes of this study are to compare the proteome of Vibrio cholerae O139 strains with that of O22, O155 and El Tot biotype epidemic strains, and to identifv whether O139 strains have a close relation with the latter. Proteins of two V. cholerae serogroup O139 strains, two El Tor biotype epidemic strains, one O22 strain, and one O155 strain were separated by two-dimensional gel electrophoresis （2-DE） ; the silver stained 2-DE gels were scanned with （ligital lmageScanner and analyzed with lmageMaster 2D Elite 3.10 software. Similarities of protein maps between these strains were analyzed. The two O139 strains had 86% proteins in common; the two El Tor biotype epidemie strains showed 84% proteins in common; O139 strains shared 67 % , 47 % and 45 % proteins with El Tor biotype epidemic strains, O22 and O 155 strains respectively. Although the proteome of O 139 strains have close similarity to that of El Tor biotype epidemic strains, great disparities exist. O139 strains may not originate from El Tor biotype directly, and a transition strain may exist.展开更多
In this paper we show that the de Rham and the Signature operators on a Riemannian manifold are all isomorphic to some twisted Atiyah-Singer operators. Then the local index theorem and local Lefschetz fixed point form...In this paper we show that the de Rham and the Signature operators on a Riemannian manifold are all isomorphic to some twisted Atiyah-Singer operators. Then the local index theorem and local Lefschetz fixed point formulas of these operators can be obtained from the corresponding theorems of twisted Atiyah-Singer operators.展开更多
Taking into account stealth, structure and maintenance, ultra-compact S-shaped intake has been widely used in modem vehicles. In this paper a series of steady numerical simulation were carried out to investigate the c...Taking into account stealth, structure and maintenance, ultra-compact S-shaped intake has been widely used in modem vehicles. In this paper a series of steady numerical simulation were carried out to investigate the complex flow mechanism in s-shaped intake, particular attention was given to examining the effect of centerline curvature on the performance and flowfield of an ultra-compact S-shaped intake. In order to validate the multi-block model, the computational results for Royal Aircraft Establishment intake 2129-M2129 which had modest centerline cur- vature distribution were corrected with available experimental test data. The numerical simulation results agreed fairly well with the experimental data, and the computational method was then used to investigate the effects of different centerline curvature distributions on performance and flow field in compact S-shaped intake. Detailed analyses of the flow visualization had exposed the different flow topologies between the cases with different cen- terline curvature. It was found that different centerline curvature distributions changed the initial location and the size of separation bubble, as well as the strength of two counter-rotating vortices at the entrance of engine.展开更多
Instability of pump turbine with S-shaped curve is characterized by large fluctuations of rotational speed during the transient processes.For investigating this phenomenon,a numerical model based on the dynamic slidin...Instability of pump turbine with S-shaped curve is characterized by large fluctuations of rotational speed during the transient processes.For investigating this phenomenon,a numerical model based on the dynamic sliding mesh method(DSSM)is presented and used to numerically solve the 3D transient flow which is characterized by the variable rotation speed of runner.The method is validated by comparison with measured data for a load rejection process in a prototype pump turbine.The results show that the calculated rotation speed agrees well with the experimental data.Based on the validated model,simulations were performed for the runaway process using an artificially assumed operating condition under which the unstable rotation speed is expected to appear.The results confirm that the instability of runner rotational speed can be effectively captured with the proposed method.Presented results include the time history profiles of unit flow rate and unit rotating speed.The internal flow characteristics in a typical unstable period are discussed in detail and the mechanism of the unstable hydraulic phenomenon is explained.Overall,the results suggest that the method presented here can be a viable alternative to predict the dynamic characteristics of pump turbines during transient processes.展开更多
文摘The purposes of this study are to compare the proteome of Vibrio cholerae O139 strains with that of O22, O155 and El Tot biotype epidemic strains, and to identifv whether O139 strains have a close relation with the latter. Proteins of two V. cholerae serogroup O139 strains, two El Tor biotype epidemic strains, one O22 strain, and one O155 strain were separated by two-dimensional gel electrophoresis （2-DE） ; the silver stained 2-DE gels were scanned with （ligital lmageScanner and analyzed with lmageMaster 2D Elite 3.10 software. Similarities of protein maps between these strains were analyzed. The two O139 strains had 86% proteins in common; the two El Tor biotype epidemie strains showed 84% proteins in common; O139 strains shared 67 % , 47 % and 45 % proteins with El Tor biotype epidemic strains, O22 and O 155 strains respectively. Although the proteome of O 139 strains have close similarity to that of El Tor biotype epidemic strains, great disparities exist. O139 strains may not originate from El Tor biotype directly, and a transition strain may exist.
文摘In this paper we show that the de Rham and the Signature operators on a Riemannian manifold are all isomorphic to some twisted Atiyah-Singer operators. Then the local index theorem and local Lefschetz fixed point formulas of these operators can be obtained from the corresponding theorems of twisted Atiyah-Singer operators.
文摘Taking into account stealth, structure and maintenance, ultra-compact S-shaped intake has been widely used in modem vehicles. In this paper a series of steady numerical simulation were carried out to investigate the complex flow mechanism in s-shaped intake, particular attention was given to examining the effect of centerline curvature on the performance and flowfield of an ultra-compact S-shaped intake. In order to validate the multi-block model, the computational results for Royal Aircraft Establishment intake 2129-M2129 which had modest centerline cur- vature distribution were corrected with available experimental test data. The numerical simulation results agreed fairly well with the experimental data, and the computational method was then used to investigate the effects of different centerline curvature distributions on performance and flow field in compact S-shaped intake. Detailed analyses of the flow visualization had exposed the different flow topologies between the cases with different cen- terline curvature. It was found that different centerline curvature distributions changed the initial location and the size of separation bubble, as well as the strength of two counter-rotating vortices at the entrance of engine.
基金supported by the National Basic Research Program of China(Grant No.2009CB724302)the National Natural Science Foundation of China(Grant No.51176168)
文摘Instability of pump turbine with S-shaped curve is characterized by large fluctuations of rotational speed during the transient processes.For investigating this phenomenon,a numerical model based on the dynamic sliding mesh method(DSSM)is presented and used to numerically solve the 3D transient flow which is characterized by the variable rotation speed of runner.The method is validated by comparison with measured data for a load rejection process in a prototype pump turbine.The results show that the calculated rotation speed agrees well with the experimental data.Based on the validated model,simulations were performed for the runaway process using an artificially assumed operating condition under which the unstable rotation speed is expected to appear.The results confirm that the instability of runner rotational speed can be effectively captured with the proposed method.Presented results include the time history profiles of unit flow rate and unit rotating speed.The internal flow characteristics in a typical unstable period are discussed in detail and the mechanism of the unstable hydraulic phenomenon is explained.Overall,the results suggest that the method presented here can be a viable alternative to predict the dynamic characteristics of pump turbines during transient processes.
