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41.
Energy transfer processes in decaying, three-dimensional, isotropic turbulence are investigated using numerical results from local energy transfer (LET) theory. The study covers a wide range of evolved, microscale Reynolds numbers (5 < Rλ < 250). It is found that the energy transfer is mainly local (between scales of similar size), but there are also some signs of nonlocal transfer at higher Reynolds number. The nature of the underlying triad-wavenumber interactions, on the other hand, seems to depend on both the Reynolds number and the wavenumber range of interest. In the energy containing and dissipation ranges, both local (all three scales of the triad interaction are of comparable size) and nonlocal (one scale is much larger than the remaining two) interactions are important, with the latter becoming more dominant as the Reynolds number increases. But our nonlocal interactions tend to be less severe than those observed by Domaradzki and Rogallo. More significantly, in the inertial range of high Reynolds number flows, the LET theory predicts dominance of local and near-local interactions. While this is contrary to the result from eddy damped quasi-normal Markovian theory that the important triad interactions are mainly nonlocal, it is closer to the Kolmogorov picture of turbulence. Another interesting result is that, despite their inherent differences, the LET theory and the full simulation of Ohkitani and Kida predict inertial-range values for the energy transfer locality function in fairly good agreement, not only with each other, but also with the analytical closure theory result for infinite Reynolds number, stationary turbulence by Kraichnan. The calculated values reveal that the contributions to the net energy transfer are predominantly from near-local interactions (scale ratios ≈ 4), which is indicative of cancellation of large numbers of highly nonlocal interactions. 相似文献
42.
43.
Shanmugasundaram B Debowski AW Dennis RJ Davies GJ Vocadlo DJ Vasella A 《Chemical communications (Cambridge, England)》2006,(42):4372-4374
Synthesis of a PUGNAc-imidazole hybrid and its characterization as an inhibitor of human O-GlcNAcase through enzyme kinetics and X-ray structural analysis. 相似文献
44.
Zusammenfassung Ancis-Difluordiazin planarer Konfiguration mit C2v-Symmetrie und antrans-Difluordiazin planarer Konfiguration mit zentrosymmetrischer Struktur mit C2h-Symmetrie wurde eine Schwingungs- und Strukturanalyse unter Verwendung eines modifizierten Valenzkraftfeldes mit sechs Kraftkonstanten ausgeführt. Die Berechnung der Kraftkonstanten erfolgte nach gruppentheoretischen Methoden auf der Grundlage der Ergebnisse neuerer Struktur- und verfeinerter Schwingungsanalysen. Die Ergebnisse werden mit den an Molekülen mit ähnlichen chemischen Bindungen und angenähert identischen Kernabständen erhobenen verglichen.
Mit 2 Abbildungen 相似文献
Potential field and force constants of cis- and trans-difluorodiazines
Vibrational and structural analysis ofcis-difluorodiazine possessing a planar configuration with C2v symmetry and oftrans-difluorodiazine possessing a planar configuration of centrosymmetrical structure with C2h symmetry has briefly been made. A modified six-force constant valence force field has been employed and the force constants have been evaluated from the recent structural and refined vibrational data for bothcis- andtrans-difluorodiazines by the group theoretical method. A brief discussion of the results has been made in relation to other molecules having similar chemical bonds with nearly identical internuclear distances.
Mit 2 Abbildungen 相似文献
45.
The CoI2(PPh3)2/Zn system effectively catalyzes the [2 + 2 + 2] ene-diyne cycloaddition of 1,6-heptadiynes with allenes in a highly regio- and chemoselective fashion to yield substituted benzene derivatives in good to excellent yields. 相似文献
46.
Neumann B Bogdanoff P Tributsch H Sakthivel S Kisch H 《The journal of physical chemistry. B》2005,109(35):16579-16586
Carbon-doped TiO2, demonstrated as an efficient photocatalyst in visible light photooxidation of organic compounds, was prepared with different doping concentrations and investigated via differential electrochemical mass spectroscopy (DEMS) and capacitive surface photovoltage (SPV) measurements in the form of thin layer electrodes. In all cases the total photocurrent as well as the surface photovoltage of the doped materials decreased markedly in relation to the undoped one. No detectable oxygen evolved from the doped electrodes in acidic solution under UV-light excitation. Since an oxidation of formic acid is still apparent, it is concluded that this oxidation occurs via isolated, catalytically poorly active trap states within the forbidden energy region. The existence of these states is confirmed by capacitive SPV measurements. 相似文献
47.
Muthian Shanmugasundaram 《Tetrahedron letters》2007,48(43):7698-7701
The [Ir(COD)Cl]2/dppe system effectively catalyzes the solid-phase [2+2+2] cycloaddition of resin-bound dipropargylamine with alkynes under microwave conditions. The reaction results in high purity of isoindoline derivatives with moderate yields. 相似文献
48.
Shanmugasundaram Veerabahu Bajorath Jürgen Christoffersen Ralph E. Petke James D. Howe W. Jeffrey Johnson Mark A. Agrafiotis Dimitris K. Lee Pil Kuhn Leslie A. Goodwin Jay T. Holloway M. Katharine Doman Thompson N. Walters W. Patrick Schreyer Suzanne Medina-Franco José L. Martinez-Mayorga Karina Restifo Linda L. 《Journal of computer-aided molecular design》2022,36(9):623-638
Journal of Computer-Aided Molecular Design - In May 2022, JCAMD published a Special Issue in honor of Gerald (Gerry) Maggiora, whose scientific leadership over many decades advanced the fields of... 相似文献
49.
Raghavachary Raghunathan Muthian Shanmugasundaram Sankaran Bhanumathi Ezekiel J. Padma Malar 《Heteroatom Chemistry》1998,9(3):327-332
Synthesis of a series of novel 1,3-diphenyl-4-aryl spiropyrazolines [5.3′] 4′-chromanones has been accomplished in good yields by regioselective 1,3-dipolar cycloaddition of diphenylnitrilimine to 3-arylidene-4-chromanones. X-ray crystal structure analysis of one of the products 4a confirms the structure and the regiochemistry of cycloaddition. © 1998 John Wiley & Sons, Inc. Heteroatom Chem 9:327–332, 1998 相似文献
50.
C. Damodaran E. R. B. Shanmugasundaram 《Journal of Radioanalytical and Nuclear Chemistry》1978,46(2):373-377
A brief report on the food pollutant-mycotoxin, citrinin, is presented. Radioactive14C-citrinin was isolated from Aspergillus candidus grown culture supplemented with14C-glucose. Quick uptake of14C-citrinin was observed in the liver and kidney of mice, after the administration of a single dose. In vitro studies with14C-citrinin reveal that it gets bound to the albumin fraction of human serum.
Part of Ph. D. Thesis submitted to the University of Madras in 1973. 相似文献