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931.
SUN Tianxu HOU Hongjia LU Jingcai XU Man GU Tiejun WANG Dandan DONG Yunliang JIANG Chunlai KONG Wei WU Yongge 《高等学校化学研究》2015,31(4):553-557
Here is reported a novel pneumolysin(Ply) mutant(PlyM2) that addresses a long-standing problem for vaccine development in this field: detoxification of Ply in the premise of retaining antigenic integrity. Structure and function of wild-type Ply(PlyWT) and PlyM2 mutants were detected and compared. Their structures were not signi- ficantly different according to the analysis by thermal-dependent fluorescence spectroscopy and circular dichroism spectroscopy. PlyM2 was confirmed to have lost hemolytic activity and yet could induce neutralizing antibodies to prevent in vitro hemolysis by PlyWT and Streptococcus pneumoniae(S. pneumoniae). These results give support to PlyM2 to be a new protein antigen for inclusion in the development of an effective pneumococcal multiprotein vaccine. 相似文献
932.
933.
The two-mode quantum electromagnetic field in the vacuum squeezed state is considered in the tomographic-probability representation.
The symplectic, center-of-mass, and photon-number tomograms for the two-mode vacuum squeezed state are obtained explicitly.
The expressions for photon statistics of the squeezed light are reconsidered using the state tomograms, and some new integral
relations are found for one and multimode orthogonal polynomials. 相似文献
934.
Man Ge Jie Feng Hailian Huang Xiaofeng Gou Chengwen Hua Bang Chen Junlong Zhao 《Journal of heterocyclic chemistry》2019,56(12):3297-3302
Six novel derivatives of 2‐ferrocenyl‐5‐aryl‐1,3,4‐oxadiazoles have been synthesized through catalytic oxidation of benzoylhydrazone with nitrophthalocyanine iron (II) as catalyst and tert‐butyl hydroperoxide as oxidant. All of the compounds have been characterized by high‐resolution mass spectrometry, 1H, 13C NMR, and infrared spectroscopy. Moreover, the antifungal activities of all new compounds have been evaluated and the results showed that the compounds exhibited excellent antifungal activities. In addition, the molecular structure of compound 1c could also be determined by X‐ray single‐crystal diffraction. 相似文献
935.
Xiaoyue Zhang Man Ho Chan Tiberiu Harko Shi-Dong Liang Chun Sing Leung 《The European Physical Journal C - Particles and Fields》2018,78(4):346
If dark matter is composed of massive bosons, a Bose–Einstein condensation process must have occurred during the cosmological evolution. Therefore galactic dark matter may be in a form of a condensate, characterized by a strong self-interaction. We consider the effects of rotation on the Bose–Einstein condensate dark matter halos, and we investigate how rotation might influence their astrophysical properties. In order to describe the condensate we use the Gross–Pitaevskii equation, and the Thomas–Fermi approximation, which predicts a polytropic equation of state with polytropic index \(n=1\). By assuming a rigid body rotation for the halo, with the use of the hydrodynamic representation of the Gross–Pitaevskii equation we obtain the basic equation describing the density distribution of the rotating condensate. We obtain the general solutions for the condensed dark matter density, and we derive the general representations for the mass distribution, boundary (radius), potential energy, velocity dispersion, tangential velocity and for the logarithmic density and velocity slopes, respectively. Explicit expressions for the radius, mass, and tangential velocity are obtained in the first order of approximation, under the assumption of slow rotation. In order to compare our results with the observations we fit the theoretical expressions of the tangential velocity of massive test particles moving in rotating Bose–Einstein condensate dark halos with the data of 12 dwarf galaxies and the Milky Way, respectively. 相似文献
936.
针对受多种因素影响的复杂道路交通系统问题,基于颗粒动力学理论,结合传统的Lighthill-WhithamRichards物理模型,建立道路交通系统的流体物理模型,采用无网格粒子与网格相结合的方法进行数值仿真,并应用于典型道路交通问题的求解.在新模型中,将车辆比拟为硬颗粒,车辆的跟车比拟为颗粒间的碰撞相互作用,已知道路情况对驾驶员操作车辆的影响比拟为流-粒两相系统中的外部流体驱动力作用,不同车道间车辆的影响比拟为颗粒间的黏性作用,从而在颗粒动力学理论的基础上,推导建立了道路交通系统拟流体模型;引入光滑离散颗粒流体动力学(SDPH)对车辆系统模型进行离散,建立"SDPH车辆"与真实车辆之间的一一对应关系,再结合有限体积方法,对道路交通构建的双流体模型进行求解,建立求解交通流体物理模型的新型仿真方法.最后,采用所建立的模型和方法对车辆汇入以及机非混合对交通系统的影响过程进行了数值仿真,所得结果与实测值符合较好,表明新的模型和方法有效性好、可靠性高,为道路交通问题的解决提供了一条全新的途径. 相似文献
937.
采用溶胶-凝胶法在Pt(111)/ Ti/ SiO2/ Si(001)基片上制备了BiFe0.95Mn0.05O3(BFMO)薄膜,并构架了Pt/ SrRuO3/ BFMO/ Pt型电容器.X射线衍射(XRD)分析发现在650℃快速退火可以得到良好结晶质量的多晶薄膜.紫光入射到薄膜表面,电滞回线发生变化,这是由于光照在薄膜内部产生的光生载流子影响了退极化场的分布.研究表明,在紫光照射下,薄膜的漏电流密度变大,电导由5.1×10-7 S增大到6.63×10-7S.通过对暗电流密度的拟合发现,BFMO薄膜为欧姆导电机制. 相似文献
938.
939.
Byoung Koo Lee Sang Jin Oh Jeong Man Mo Tae Eun Lee 《Journal of sound and vibration》2008,318(1-2):227-246
The differential equations governing out-of-plane free vibrations of the elastic, horizontally curved beams with variable curvature are derived and solved numerically to obtain natural frequencies and mode shapes for parabolic, sinusoidal and elliptic beams with hinged–hinged, hinged–clamped, and clamped–clamped end constraints, in which the effects of the rotatory and torsional inertias and shear deformation are included. Experimental measures of frequencies for several laboratory-scale parabolic models serve to validate the theoretical results. 相似文献
940.
A new etherified starch, δ-hydroxybutyl starch (δ-HBS), was prepared by utilising 4-chlorobutan-1-ol as the etherifying reagent. The method of Zeisel gas chromatography for the determination of the molar substitution was described. This technique offers a simple and rapid method for quantitative analysis with reproducible results. Meanwhile, the mechanism of the Zeisel reaction was also investigated. 相似文献