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801.
The present paper focuses on the analysis of unsteady flow and heat transfer regarding an axisymmetric impinging synthetic
jet on a constant heat flux disc. Synthetic jet is a zero net mass flux jet that provides an unsteady flow without any external
source of fluid. Present results are validated against the available experimental data showing that the SST/k − ω turbulence model is more accurate and reliable than the standard and low-Re k − ε models for predicting heat transfer from an impinging synthetic jet. It is found that the time-averaged Nusselt number
enhances as the nozzle-to-plate distance is increased. As the oscillation frequency in the range of 16–400 Hz is increased,
the heat transfer is enhanced. It is shown that the instantaneous Nu distribution along the wall is influenced mainly by the interaction of produced vortex ring and wall boundary layer. Also,
the fluctuation level of Nu decreases as the frequency is raised. 相似文献
802.
Abu-Omar MM 《Dalton transactions (Cambridge, England : 2003)》2011,40(14):3435-3444
Manganese(V) imido complexes of 5,10,15-tris(pentafluorophenyl)corrole (H(3)tpfc) can be prepared by the reaction of Mn(III)(tpfc) and organic nitrene generated from either photolytic or thermal activation of organic azides. The terminal imido complexes of manganese(V) were among the first structurally characterized examples of Mn(V) terminal imido complexes in the literature. They feature a short Mn≡N triple bond and a nearly linear M[triple bond, length as m-dash]N-C angle. The ground state of (tpfc)Mn(V)(NAr) is singlet. Contrary to expectations, arylimido complexes of manganese(V) were stable to moisture and did not undergo [NR] group transfer to olefins. Manganese(V) imido corrole with an activated tosyl imido ligand was prepared from iodoimine (ArINTs) and manganese(III) corrole. The resulting complex (tpfc)Mn(NTs) is paramagnetic (S = 1), hydrolyzes to (tpfc)Mn(O) in the presence of water, abstracts hydrogen atoms from benzylic C-H bonds, and catalyzes aziridination of alkenes. Mechanistic studies on the aziridination and hydrogen atom transfer reactions are reviewed. This perspective also describes the reaction chemistry of the heme enzyme chlorite dismutase, the mechanism by which dioxygen is formed on a single-metal site, and recent advances in functional modelling of this enzyme. We also compare the reactivity of water-soluble iron versus manganese porphyrins towards the chlorite anion. 相似文献
803.
Najafpour MM Nayeri S Pashaei B 《Dalton transactions (Cambridge, England : 2003)》2011,40(37):9374-9378
A nano-size amorphous calcium-manganese oxide shows efficient water oxidation activity in the presence of cerium(IV) ammonium nitrate. 相似文献
804.
Delazar A Delnavazi MR Nahar L Moghadam SB Mojarab M Gupta A Williams AS Mukhlesur Rahman M Sarker SD 《Natural product research》2011,25(1):8-16
Reversed-phase preparative HPLC analyses of the methanol extract of the aerial parts of Stachys lavandulifolia afforded a new phenylethanoid glycoside, 4,3',4'-trimethoxy-lavandulifolioside A, named lavandulifolioside B, together with three other known phenylethanoid glycosides, lavandulifolioside A, verbascoside and leucosceptoside A, and an iridoid glycoside 5-O-β-allopyranosyloxy-aucubin (5-O-β-allopyranosyl-monomelittoside). While the structures of the known compounds, except the iridoid glycoside, were established by direct comparison of their spectroscopic data with respective literature data, lavandulifolioside B and 5-O-β-allopyranosyloxy-aucubin were identified comprehensively by extensive 1D and 2D NMR analyses. The distribution of the isolated compounds within the genus Stachys has been discussed. 相似文献
805.
806.
Mahdi Mirzaee Tayebeh Tamizkar Gholamhossein Mohammadnezhad Hamid Reza Khavasi Mostafa M. Amini 《Comptes Rendus Chimie》2011,14(10):927-933
Stochiometric reaction of salicylaldoxime and tantalum or niobium ethoxide in toluene at room temperature resulted in formation of [M2O(C7H5NO2)2(C2H5O)4], M=Ta and Nb which were crystallized from CH2Cl2 at −5 °C and characterized by spectroscopic techniques. The molecular structures of [Ta2O(C7H5NO2)2(C2H5O)4] was determined by single-crystal X-ray diffraction and compared with molecular structure of [Nb2O(C7H5NO2)2(C2H5O)4]. The geometries at metal atoms are distorted octahedron which shared an apex through bridged oxygen. Each dianionic salicylaldoximate ligand chelates to the one metal ion through its phenolic oxygen and oximate nitrogen atoms, and to another metal ion through its oximate oxygen atom. 相似文献
807.
808.
Reza?Zamiri B.?Z.?AzmiEmail author Majid?Darroudi Amir?R.?Sadrolhosseini M.?S.?Husin A.?W.?Zaidan M.?A.?Mahdi 《Applied Physics A: Materials Science & Processing》2011,102(1):189-194
Silver nanoparticles inside the starch solution have been successfully fabricated by laser ablation of a silver plate immersed
in starch solution. The ablation has been done using a Q-switched Nd:YAG laser at 10 Hz repetition rate. The starch solution
allows for the formation of silver nanoparticles with uniform particle diameters and well dispersed. The ablation was performed
at different time durations to study the influence of the laser ablation time on efficiency of particle formation and sizes.
The Spatial Self-phase modulation phenomena which can determine the nonlinear optical property of the samples were also investigated
for starch solutions containing silver nanoparticles. 相似文献
809.
810.
Let R be a commutative ring with identity. We will say that an R-module M satisfies the weak Nakayama property, if IM=M, where I is an ideal of R, implies that for any x∈M there exists a∈I such that (a−1)x=0. In this paper, we will study modules satisfying the weak Nakayama property. It is proved that if R is a local ring, then R is a Max ring if and only if J(R), the Jacobson radical of R, is T-nilpotent if and only if every R-module satisfies the weak Nakayama property. 相似文献