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931.
The numerical simulation method of radiative entropy generation in participating media presented by Caldas and Semiao [Entropy generation through radiative transfer in participating media: analysis and numerical computation. JQSRT 2005;96:423-37] is extended to analyze the radiative entropy generation in the enclosures filled with semitransparent media. A discrete ordinates method is used to solve radiative transfer equation and radiative entropy generation. Two different examples are employed to verify the numerical simulation method of radiative entropy generation in the enclosure. Numerical results of dimensionless radiative entropy generation of enclosure are identical to that of entire thermodynamics analysis for the enclosure system. This numerical simulation method can be used in the entropy generation analysis of high-temperature systems such as boilers and furnaces, in which radiation is the dominant mode of heat transfer. 相似文献
932.
L.H. Liu 《Journal of Quantitative Spectroscopy & Radiative Transfer》2007,103(3):536-544
To avoid the complicated and time-consuming computation of curved ray trajectories, a least-squares finite element method based on discrete ordinate equation is extended to solve the radiative transfer problem in a multi-dimensional semitransparent graded index medium. Four cases of radiative heat transfer are examined to verify this least-squares finite element method. Linear and nonlinear graded index are considered. The predicted dimensionless net radiative heat fluxes are determined by the least-squares finite element method and compared with the results obtained by other methods. The results show that the least-squares finite element method is stable and has a good accuracy in solving the multi-dimensional radiative transfer problem in a semitransparent graded index medium, while the Galerkin finite element method sometimes suffers from nonphysical oscillations. 相似文献
933.
E. Xenogiannopoulou P. Aloukos S. Couris E. Kaminska E. Dynowska 《Optics Communications》2007,275(1):217-222
Au films of thickness ranging between 5 and 52 nm were prepared by sputtering on quartz substrates and their third-order nonlinear optical response was investigated by Optical Kerr effect (OKE) and Z-scan techniques using 532 nm, 35 ps laser pulses. All prepared films were characterized by XRD, AFM and UV-VIS-NIR spectrophotometry while their third-order susceptibility χ(3) was measured and found to be of the order of 10−9 esu. The real and imaginary parts of the third-order susceptibility were found in very good agreement with experimental results and theoretical predictions reported by Smith et al. [D.D. Smith, Y. Yoon, R.W. Boyd, Y.K. Cambell, L.A. Baker, R.M. Crooks, M. George, J. Appl. Phys. 86 (1999) 6200]. 相似文献
934.
Influences of decoherence on the generation of a macroscopic superposition state using weak cross-Kerr effect
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Considering a system in which a single photon and a coherent field propagate through a Kerr medium, when the weak cross-Kerr interaction between the coherent state and the single photon under decoherence is involved, this paper derives analytically a macroscopic superposition state by the superoperator method and investigates the influences of decoherence on the coherence properties of the obtained state. It finds that the macroscopic superposition state will experience evolution from a pure superposltion state to a mixed state in a dissipative environment and the Kerr effect makes the field display a periodic revival from decoherence for a short time. 相似文献
935.
Biswanath Das Harish Holla Katta Venkateswarlu Anjoy Majhi 《Tetrahedron letters》2005,46(51):8895-8897
Treatment of Baylis-Hillman adducts with iodosobenzene (PhIO) in the presence of a catalytic amount of KBr in water at room temperature afforded the corresponding acyloxiranes in good yields. 相似文献
936.
Some algebraically explicit analytical solutions are derived for the anisotropic Brinkman model—an improved Darcy model—describing
the natural convection in porous media. Besides their important theoretical meaning (for example, in analyzing the non-Darcy
and anisotropic effects on the convection), such analytical solutions can be the benchmark solutions that can promote the
development of computational heat and mass transfer. Some solutions considering the anisotropic effect of permeability have
been given previously by the authors, and this paper gives solutions including the anisotropic effect of thermal conductivity
and the effect of heat sources. 相似文献
937.
Chia-Wei?Sun Yih-Ming?Wang Chih-Chung?YangEmail author Yean-Woei?Kiang Long-Sheng?Lu Ming-Jai?Su 《Optical Review》2003,10(5):488-492
In this paper we demonstrated the effectiveness of imaging in a tissue phantom with isotropic scattering using polarization discrimination combined with the time gating method. This simple polarization discrimination technique was shown ineffective when it was applied to filamentous tissues. In this situation, we utilized the time-gated degree of polarization (DOP) imaging technique to show that the DOP measurement was quite effective for high-quality imaging of objects in filamentous tissues. We also applied this technique to the characterization of myocardial tissues and showed the difference between normal and abnormal tissues. In addition, we demonstrated a novel method for target depth determination in a turbid medium based on co-polarized light measurements. This method relied on the strong dependence of transmitted co-polarized intensity on target depth. 相似文献
938.
An experimental investigation of the optical properties of a bilateral straight-through-flow small-scale (1.7410–2 m) vortex tube has been carried out experimentally, and the influence of this tube on an axial small-section (310–3 m) laser beam has been studied. Additional data confirming the reliability of the gas-dynamical model of formation of laser beams with an intensity dip at the center are obtained.__________Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 1, pp. 58–62, January–February, 2005. 相似文献
939.
Taniguchi Hiroshi Kurosawa Akinori Tanosaki Shinji Devaraj B. Inaba Humio 《Optical and Quantum Electronics》2000,32(2):125-135
The first laser action of active-particles of 1–2 m in diameter, red fluorescent-powder (FP), dispersed in nonactive (nonlasing) 100 m-sized liquid microdroplets is reported. Lasing characteristics of FP-containing microdroplets by mixing Intralipid-10% as highly scattering turbid media are also described. Well-defined lasing thresholds can be confirmed from the FP-dispersed pure microdroplets, and lowered lasing threshold along with enhanced lasing emission is achieved by appropriately mixing the Intralipid-10% solution. Lasing threshold in these microdroplets can be determined not through the spectral narrowing features but through the input–output data. We believe that these new microdroplet configurations offer one of the new categories of lasing media and they seem also to simulate to some biological pigments or organelles contained in cells and small tissues. 相似文献
940.
Jiying Huang Yihua Li Gan Du 《International Journal of Infrared and Millimeter Waves》2000,21(1):101-105
We use an equivalent random system for the discrete rain medium. A serial model of computing cross-polar discrimination (XPD) is given by system model with propagation experiment data in Xi'an, China. The calculated results show this method is effective and straightforward. 相似文献