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101.
Ioannis G. Tigelis Jean-Yves Raguin Zisis C. Ioannidis George P. Latsas Angelos J. Amditis 《International Journal of Infrared and Millimeter Waves》2008,29(4):432-442
The dispersion characteristics of a circular cylindrical waveguide with periodic surface corrugations consisting of rectangular
grooves with smoothing are examined using the Space Harmonic Method (SHM). The whole structure is divided into two regions,
one describing the propagation volume and one inside the grooves. In the first region, the Floquet theorem is applicable and
the field distribution is expressed as a summation of spatial Bloch components, whereas in the second one an appropriate Fourier
expansion of standing waves is used. Applying the boundary conditions an infinite system of equations is obtained, which is
solved numerically by truncation. Several cases are considered, including the limiting cases of a sinusoidal and a rectangular
corrugation profile, to check the accuracy of the method proposed as well as its dependence on the corrugation profile. Numerical
results are presented only for transverse magnetic modes, although the formalism can be easily extended to include all kinds
of waves that can in principle propagate in such a structure. 相似文献
102.
Ioannis Papanastasiou Andrew Tsotinis George B. Foscolos S. Radhika Prathalingam John M. Kelly 《Journal of heterocyclic chemistry》2008,45(5):1401-1406
Aiming at the development of new adamantano building blocks for treating African trypanosomiasis, we report on the synthesis of spiro adamantane 2‐imidazolines 8a‐f and 9a‐c , and their congeneric 5‐(1‐adamantyl)imidazolines 14 and 15 . The potency of these compounds against Trypanosoma brucei was compared to that of rimantadine and found, in the case of compound 14e , to be three fold higher. Together with the other active compounds, 14b and 15b , which were equipotent to rimantadine, the new molecules illustrate the synergistic effect of the lipophilic character of adamantane and the C1 amidine functionality on trypanocidal activity. 相似文献
103.
We present a semigrand ensemble Monte Carlo and Brownian dynamics simulation study of structural and dynamical properties of polydisperse soft spheres interacting via purely repulsive power-law potentials with a varying degree of "softness." Comparisons focus on crystal and amorphous phases at their coexistence points. It is shown through detailed structural analysis that as potential interactions soften, the "quality of crystallinity" of both monodisperse and polydisperse systems deteriorates. In general, polydisperse crystalline phases are characterized by a more ordered structure than the corresponding monodisperse ones (i.e., for the same potential softness). This counter-intuitive feature originates partly from the fact that particles of different sizes may be accommodated more flexibly in a crystal structure and from the reality that coexistence (osmotic) pressure is substantially higher for polydisperse systems. These trends diminish for softer potentials. Potential softness eventually produces substitutionally disordered crystals. However, substitutional order is apparent for the hard-spherelike interactions. Diffusionwise, crystals appear quite robust with a slight difference in the vibrational amplitudes of small and large particles. This difference, again, diminishes with potential softness. Overcrowding in amorphous polydisperse suspensions causes "delayed" diffusion at intermediate times. 相似文献
104.
We present artificial boundary conditions for the numerical simulation of compressible flows using high-order accurate discretizations with the discontinuous Galerkin (DG) finite element method. The construction of the proposed boundary conditions is based on characteristic analysis and applied for boundaries with arbitrary shape and orientation. Numerical experiments demonstrate that the proposed boundary treatment enables to convect out of the computational domain complex flow features with little distortion. In addition, it is shown that small-amplitude acoustic disturbances could be convected out of the computational domain, with no significant deterioration of the overall accuracy of the method. Furthermore, it was found that application of the proposed boundary treatment for viscous flow over a cylinder yields superior performance compared to simple extrapolation methods. 相似文献
105.
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107.
The effect of the dilatancy of masonry interfaces and of the size of the building blocks on the strength of masonry structures is quantified herein. The study focuses mainly on out-of-plane loadings, which can appear due to various factors such as wind, earthquakes or explosions. The analysis is performed using the Discrete Element Method (DEM), which allows to access directly various micro-mechanical parameters, such as the joints dilatancy angle and the size of the building blocks. Detailed DEM numerical models of existing experimental configurations are presented. The numerical results are first compared and validated towards the experimental observations and then they are used to derive qualitative and quantitative conclusions regarding the effects of joints dilatancy and blocks size. It is shown that dilatancy plays an important role on the overall strength of masonry even under low confinement. The size of the blocks is also an important parameter that needs to be considered in the modeling of masonry structures. 相似文献
108.
Noah J. Tremblay Alon A. Gorodetsky Dr. Marshall P. Cox Theanne Schiros Dr. Bumjung Kim Rachel Steiner Zachary Bullard Aaron Sattler Woo‐Young So Dr. Yoshimitsu Itoh Dr. Michael F. Toney Dr. Hirohito Ogasawara Dr. Arthur P. Ramirez Prof. Ioannis Kymissis Dr. Michael L. Steigerwald Dr. Colin Nuckolls Prof. 《Chemphyschem》2010,11(4):742-742
109.
110.
A tris(bromo-methylphenylene)triazine and its corresponding phosphine oxide derivative have been synthesized; the latter compound was found to be a potent ligand for the hydroformylation reaction. Suzuki coupling of the mono-pinacolboronate derivative of the former compound with a tris(iodo-methylphenylene)triazine was possible at two of the three iodine atoms, yielding a bromo- and iodo-methylphenylene periphery-functionalized triazine-based dendritic molecule with a 3,3′-dimethyl-biphenyl linker. 相似文献