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41.
42.
Axisymmetric viscous fluid flows past spheroids are considered. The time-independent complete Navier-Stokes equations written in a spherical coordinate system are used for describing the flow. The problem is solved by the stabilization method on the basis of a variable direction scheme. The input coordinate system is transformed in order to construct a regular computational grid. As a result of the numerical investigation, the stream patterns of flow past elongated and oblate spheroids are obtained for various values of the determining parameters. Numerical values of the dimensions of the circulation zone and the drag coefficient are given for various values of the spheroid semi-axis ratio in the domain of moderate Reynolds numbers. 相似文献
43.
Farzana Ahmad Young Jae Jeon 《International Journal of Polymer Analysis and Characterization》2017,22(8):659-668
In this study, the dye-doped polymer dispersed liquid crystals (PDLC) gratings techniques performed by the various research groups or being developed are briefly reviewed. Especially, the electrically switched diffraction and holographic gratings, have attained much attention by various research groups working in the PDLC-related display studies. The fabrication methodologies used for such grating texture, include like the conventional dye-doped PDLC grating, Azo-dye doped PDLC gratings, and lasing techniques etc., adopted for dye-doped PDLC gratings. The useful features and characteristics of their fabrication process of such gratings are discussed. Finally, some of the future perspectives on this particular research field are presented. 相似文献
44.
Yang ZHOU Qing-Qing CHENG Qing-Hong HUANG Zhi-Qing ZOU Liu-Ming YAN Hui YANG 《物理化学学报》2017,33(7):1429-1435
过渡金属氮掺杂碳基催化剂已成为替代铂基氧还原反应(ORR)电催化剂的理想选择。本文通过静电纺丝技术制备了高比表面、高度分散的钴原子配位氮掺杂的碳纳米纤维催化剂(Co-N/C)。X射线衍射(XRD)和高分辨率透射电镜(HRTEM)结果证实Co元素高度分散于制备的Co-N/C催化剂中。X射线光电子能谱结果表明N元素主要以吡啶N和石墨N形式存在。该Co-N/C催化剂对ORR反应呈现出较高的电催化活性,其氧还原起始和半波电位分别为0.92 V和0.80 V(相对于标准氢电极),接近于商业化Pt/C催化剂的性能。以制备的Co-N/C催化剂作为阴极,25℃下锌空气燃料电池的开路电位1.54 V、最大功率密度达到了190 m V·cm~(-2)表明该催化剂具有良好的应用前景。 相似文献
45.
46.
V. I. Nasonov 《Journal of Applied Spectroscopy》2006,73(2):234-244
Radiation scattering by particles of condensed phase in an ablation plasma plume has been experimentally studied during quasicontinuous
laser irradiation (λ = 1.06 μm, q = 0.1–9 MW/cm2, τ ∼ 1.5 msec) of duraluminum D16T, aluminum A99, and bismuth. The particle size distribution and the nature of their dispersal
during irradiation was studied in scattered light (λ = 0.69 μm) from individual particles that could be visually observed
on photographs. It was found that under the pressure developed in the plume, large particles ejected from the irradiated zone
can move backward and return to the target (D16T). The plume (Bi) becomes brighter due to ablation of particles in the path
of the laser beam. The directional scattering coefficients for scattering from the local zone on the axis of the plume, measured
during the laser pulse, were used to study the relationship between the dynamics of entry of condensed phase into the plume,
shielding of the target by the particles, and brightening of the plume under the action of the incident laser radiation.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 2, pp. 210–219, March–April, 2006. 相似文献
47.
We have investigated the pressure effect on the eletrorotation (ER) spectrum of living cell suspensions byconsidering the particle shape effect. In particular, we consider coated oblate spheroidal particles and present a theoreticalstudy of ER based on the spectral representation theory. Analytic expressions for the characteristic frequency as wellas the dispersion strength can be obtained, thus simplifying the fitting of experimental data on oblate spheroidal cellsthat abound in the literature. From the theoretical analysis, we find that the cellshape, coating as well as materialparameters can change the ER spectrum. We demonstrate a good agreement between our theoretical predictions andexperimental data on human erthrocytes suspensions. 相似文献
48.
49.
The paradigm of randomly-furcating stochastic differential games incorporates additional stochastic elements via randomly branching payoffs in stochastic differential games. This paper considers dynamically stable cooperative solutions in randomly furcating stochastic differential games. Analytically tractable payoff distribution procedures contingent upon specific random realizations of the state and payoff structure are derived. This new approach widens the application of cooperative differential game theory to problems where the evolution of the state and future environments are not known with certainty. Important cases abound in regional economic cooperation, corporate joint ventures and environmental control. An illustration in cooperative resource extraction is presented. 相似文献
50.
导体旋转椭球电学量的一种计算方法 总被引:8,自引:4,他引:4
用一种新方法,计算了孤立导体旋转椭球的面电荷密度、电容、电势和电场强度,并得出相应的解析表达式。 相似文献