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991.
992.
In this work, we investigate the angular dependence of transmission and reflection in the single-negative (SNG) materials. We consider a model structure of a SNG bilayer which consists of the epsilon-negative (ENG) and mu-negative (MNG) layers. The wave transmission and reflection properties due to the losses from the ENG and MNG materials are specifically investigated. With the presence of losses in the ENG and MNG materials, some unusual wave properties will be explored and numerically demonstrated.  相似文献   
993.
A mixture of a UV absorber (Tinuvin 234 or Tinuvin 329) and a UV stabilizer (Tinuvin 770) was analyzed using matrix‐assisted laser desorption/ionization mass spectrometry (MALDI‐MS) without any matrix. Fragmentation patterns of the UV absorbers and stabilizer were also investigated. The mass spectra showed the [M+H]+ ions and some fragment ions. Tinuvin 234, Tinuvin 329, and Tinuvin 770 generated three (m/z 119, 370, 432), one (m/z 252), and two (m/z 124 and 140) fragment ions, repectively. These fragment ions can be used to identify the chemical structures of the UV absorbers and stabilizer. Since the UV absorber performed a role as the matrix, the ion abundance of the UV stabilizer was enhanced by mixing with the UV absorber. When organic materials extracted from polypropylene (PP) containing the UV absorber and stabilizer were directly analyzed using MALDI‐MS without any matrix, the protonated molecule of the UV stabilizer was detected in abundance but the product ions of the UV absorber were not observed. When 2,5‐dihydroxybenzoic acid was used as a matrix, the protonated molecule of the UV absorber was observed. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   
994.
995.
This study extends the upstream flux‐splitting finite‐volume (UFF) scheme to shallow water equations with source terms. Coupling the hydrostatic reconstruction method (HRM) with the UFF scheme achieves a resultant numerical scheme that adequately balances flux gradients and source terms. The proposed scheme is validated in three benchmark problems and applied to flood flows in the natural/irregular river with bridge pier obstructions. The results of the simulations are in satisfactory agreement with the available analytical solutions, experimental data and field measurements. Comparisons of the present results with those obtained by the surface gradient method (SGM) demonstrate the superior stability and higher accuracy of the HRM. The stability test results also show that the HRM requires less CPU time (up to 60%) than the SGM. The proposed well‐balanced UFF scheme is accurate, stable and efficient to solve flow problems involving irregular bed topography. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   
996.
Small vapor compression refrigeration systems incorporate a non-adiabatic capillary tube called a capillary tube-suction line heat exchanger (SLHX) in order to improve performance. The thermodynamic properties of the refrigerant in the capillary tube and suction pipe are influenced by associated phenomena. This study compares various relevant models. Based on the comparison recommended correlations were selected and the simulation results show that the friction factor model has the most dominant.  相似文献   
997.
998.
A plasmonic multilayer structure (PMS) is proposed for photovoltaic cells with an ultrathin active layer that is 30 nm amorphous Si (α-Si). The optical properties of the PMS are analyzed by rigorous coupled-wave analysis (RCWA) and finite-difference time-domain (FDTD) method. Using the PMS, the incident light can be trapped into localized surface plasmon (LSP) and then the localized surface plasmon induces the surface plasmon (SP) that propagates transversely within the α-Si layer. Compared with the indium tin oxide (ITO)/α-Si/Ag structure, the photon number absorbed by PMS increase 28.7% while a normal incident transverse magnetic (TM) polarization wave is applied.  相似文献   
999.
Thermophysical properties of liquid alloys are usually difficult to measure, especially for high melting point and reactive alloys. In this work, the surface tensions of superheated and undercooled liquid Ti55Al45, Ti50Al45Nb5 and Ti45Al45Nb10 alloys are determined by using oscillating drop method under electromagnetic levitation state. The experimental results of Ti–Al and Ti–Al–Nb alloys display linear temperature dependence. The maximum undercoolings of 259 (0.143T L), 268 (0.146T L) and 275 K (0.147T L) are respectively achieved for these three alloys. Furthermore, the viscosities of liquid Ti55−x Al45Nb x alloys are also derived from the experimental results.  相似文献   
1000.
The nonisothermal decomposition kinetics of Ginkgo biloba leaves polyprenol (GBP) and cleaved situation of its chemical bond during thermal decomposition process were first investigated using thermogravimetric (TG) and TG‐FTIR technology. The results of thermal decomposition kinetics revealed that the nonisothermal decomposition mechanism of GBP corresponds to first‐order chemical reaction with n = 1, integral form g(a) = –ln(1 – a) and differential form f(a) = 1 – a. TG‐FTIR results demonstrated that absorbance of –CH3, unsaturated C–H bond, =CH2, accumulated C=C, –OH, and so on constantly increased with thermal decomposition reaction went on. In addition, storage life of GBP was also evaluated. These data could provide theoretical guidance for purification under high temperature and other thermal application of GBP.  相似文献   
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