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981.
Sin-Chung Chang Yuhui Wu Xiao-Yen Wang 《International Journal of Computational Fluid Dynamics》2013,27(5):359-380
A local time-stepping procedure for the space-time conservation element and solution element (CESE) method has been developed. This new procedure allows for variation of time-step size in both space and time, and can also be extended to become multi-dimensional solvers with structured/unstructured spatial grids. Moreover, it differs substantially in concept and methodology from the existing approaches. By taking full advantage of key concepts of the CESE method, in a simple and efficient manner it can enforce flux conservation across an interface separating grid zones of different time-step sizes. In particular, no correction pass is needed. Numerical experiments show that, for a variety of flow problems involving moving shock and flame discontinuities, accurate and robust numerical simulations can be achieved even with a reduction in time-step size on the order of 10 or higher for grids across a single interface. 相似文献
982.
In this note, we revisit the single-index model with heteroscedastic error, and recommend an estimating equation method in terms of transferring restricted least squares to unrestricted least squares: the estimator of the index parameter is asymptotically more efficient than existing estimators in the literature in the sense that it is of a smaller limiting variance. 相似文献
983.
在模糊概念格中讨论了基于截形式背景的属性约简,其中着重分析了在精度的偏序关系下属性约简的包含关系,并证明了此说法的正确性,进而还举例说明了其正确性;在此基础之上,本文还给出了在用不同精度把模糊概念格转换了经典概念格时造成的误差,并给出其算法,最后举例说明其有效性. 相似文献
984.
985.
A number of novel strobilurin analogues containing substituted N-phenylpyrimidin-2-amines were synthesized.The structures of these new compounds were confirmed by ~1H NMR,IR and elemental analysis.Biological evaluation in the greenhouse showed several compounds have good fungicidal activities at 25 mg/L. 相似文献
986.
C.C. Chang Y.P. Tong T.C. Chen H.F. Yau P.X. Ye 《Applied physics. B, Lasers and optics》2000,71(1):47-50
A pentagon-shaped undoped BaTiO3 crystal was used to construct a high-quality mutually pumped phase conjugator. It yields two very stable phase-conjugate outputs (ǃ.7% fluctuation in intensity) with high reflectivity (the highest ᅝ%) when the two incident beams are of equal intensities. The response time of the conjugator is rather fast (ƻ s) and the tolerance of the acceptance angle is large too (걄°). Fine structures (35 7m) in an image, after passing through a phase aberrator, can be recovered by the conjugate waves yielded by this conjugator. 相似文献
987.
988.
In this work,a novel hollow fiber membrane extractor was set up to extract inorganic anions from ethyl acetate using deionized water.Inorganic anions in slightly soluble organic solvents can be determined by the in-line hollow fiber membrane extractor coupled with ion chromatography at first time.Different aspects of the extraction procedure such as magnetic stirring speed, extraction flow rate and extraction time were optimized to achieve high extraction efficiency and good separation results. Satisfact... 相似文献
989.
990.
S. Shanmuga Sundara Raj Hoong‐Kun Fun Zhong‐Lin Lu Wen Xiao Xiao‐Yang Gong Chang‐Ming Gen 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(8):1013-1014
The crystal structure of the title compound, C15H14N2O2·H2O, is in the keto tautomeric form and the configuration at the azomethine C=N double bond is E. The molecule is non‐planar, with a dihedral angle of 27.3 (1)° between the aromatic rings. The crystal structure is stabilized by extensive hydrogen bonding involving the water molecule and hydrazone moiety. 相似文献