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101.
Development of circular function‐based gas‐kinetic scheme (CGKS) on moving grids for unsteady flows through oscillating cascades 下载免费PDF全文
In this paper, the circular function‐based gas‐kinetic scheme (CGKS), which was originally developed for simulation of flows on stationary grids, is extended to solve moving boundary problems on moving grids. Particularly, the unsteady flows through oscillating cascades are our major interests. The main idea of the CGKS is to discretize the macroscopic equations by the finite volume method while the fluxes at the cell interface are evaluated by locally reconstructing the solution of the continuous Boltzmann Bhatnagar–Gross–Krook equation. The present solver is based on the fact that the modified Boltzmann equation, which is expressed in a moving frame of reference, can recover the corresponding macroscopic equations with Chapman–Enskog expansion analysis. Different from the original Maxwellian function‐based gas‐kinetic scheme, in improving the computational efficiency, a simple circular function is used to describe the equilibrium state of distribution function. Considering that the concerned cascade oscillating problems belong to cases that the motion of surface boundary is known a priori, the dynamic mesh method is suitable and is adopted in the present work. In achieving the mesh deformation with high quality and efficiency, a hybrid dynamic mesh method named radial basic functions‐transfinite interpolation is presented and applied for cascade geometries. For validation, several numerical test cases involving a wide range are investigated. Numerical results show that the developed CGKS on moving grids is well applied for cascade oscillating flows. And for some cases where nonlinear effects are strong, the solution accuracy could be effectively improved by using the present method. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
102.
Li Zhongyang Yang Lulu Wang Kaiwu Shi Chenxu Chen Zhiliang Xu Juan Bing Pibin Zhu Anfu Xu Degang Zhong Kai Yao Jianquan 《Optical Review》2023,30(4):411-417
Optical Review - A novel scheme that generates terahertz optical frequency comb (THz OFC) based on optimized cascaded difference frequency generation (OCDFG) with an aperiodically poled lithium... 相似文献
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The hierarchical reconstruction (HR) [Liu, Shu, Tadmor and Zhang, SINUM '07] has been successfully applied to prevent oscillations in solutions computed by finite volume, Runge-Kutta discontinuous Galerkin, spectral volume schemes for solving hyperbolic conservation laws. In this paper, we demonstrate that HR can also be combined with spectral/hp element method for solving hyperbolic conservation laws. An orthogonal spectral basis written in terms of Jacobi polynomials is applied. High computational efficiency is obtained due to such matrix-free algorithm. The formulation is conservative, and essential nomoscillation is enforced by the HR limiter. We show that HR preserves the order of accuracy of the spectral/hp element method for smooth solution problems and generate essentially non-oscillatory solutions profiles for capturing discontinuous solutions without local characteristic decomposition. In addition, we introduce a postprocessing technique to improve HR for limiting high degree numerical solutions. 相似文献
105.
Zhiliang Jiang Guiqing Wen Yanyan Fan Caina Jiang Qingye Liu Zhi Huang Aihui Liang 《Talanta》2010,80(3):1287-6029
Single strand DNA (ssDNA) was used to modify nanogold to obtain a nanogold-aptamer resonance scattering (RS) probe (NGssDNA) for Hg2+, based on the formation of stable thymine-Hg2+-thymine (T-Hg2+-T) mismatches and aggregation of the released nanogold particles. After removing the aggregated particles by filtrate membrane, the excess NGssDNA in the filtration solution exhibit catalytic effect on the gold particle reaction between HAuCl4 and ascorbic acid (AA) that appear as RS peak at 596 nm. When Hg2+ concentration increased, the RS intensity at 596 nm decreased. The decreased intensity is linear to Hg2+ concentration in the range of 0.00008-0.888 ng/mL Hg2+, with detection limit of 0.000034 ng/mL. The nanogold-aptamer catalytic RS assay was applied to determination of Hg2+ in water with satisfactory results. 相似文献
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Gold nanoparticles in size of about 10 nm was used to label goat anti-human complement 3 (anti-C3) to obtain a sensitive and selective immunoresonance scattering spectral probe for C3. It was based on the immune reaction between labeled anti-C3 and C3 in the pH 5.6 Na2HPO4–citric acid buffer solutions and in presence of polyethylene glycol (PEG). The resonance scattering (RS) intensity at 560 nm enhanced greatly with C3. Well linear relationships between the enhanced RS intensity (IRS) and the C3 concentration in the range of 8.33–200 ng ml−1 were obtained, with a detection limit of 2.8 ng ml−1 and the limit of quantification 8.51 ng ml−1 for C3. The convenient and selective and sensitive assay was applied to quantification of C3 in human sera, with satisfactory results. 相似文献
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Guo X Zhou Y Zhang D Yin B Liu Z Liu C Lu Z Huang Y Zhu D 《The Journal of organic chemistry》2004,69(25):8924-8931
A new spiropyran (SP2) with the stable merocyanine form (MC2) both in solution and in the solid state at room temperature was designed and synthesized. The stability of MC2 is believed to be due to the electron-withdrawing effect of both the quinoline and the trifluoromethyl groups. (1)H NMR spectra indicate that the ratio of the open form vs the closed form of SP2 is dependent on the polarity of solvents. Single crystals composed of only the open form (MC2) were successfully obtained. X-ray structural analysis indicates that except trifluoromethyl and two methyl groups MC2 is completely planar with an s-trans,s-cis conformation. It should be noted that this is the first report of the X-ray crystal structure of the pure open form of spiropyran. MC2 can be slowly transformed into SP2 at -30 degrees C or lower temperature, and the process is accelerated by visible light irradiation. This special photochromic behavior can be explained by the calculated thermodynamic data. The spectral properties of SP2/MC2 in the presence of different metal ions are also studied, and the results show the potential application of SP2/MC2 in sensing metal ions. 相似文献
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