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1.
Zhuang W. H. Gray D. Etemadi K. Benenson D. M. 《Plasma Chemistry and Plasma Processing》1995,16(1):S127-S139
Numerical modeling and experimental measurements have been performed to study the effects of powder carrier gas flow rates and powder sizes on the deposition offset in a plasma spray of yttria-stablized zirconia. The mathematical model involved simultaneous solution of the continuity, momentum and energy equations of the plasma gas, the dynamics and heat transfer of powder particles in the plasma, and the coupling effects between the plasma and panicles. Experiments included measurement of particle velocities by laser strobe technique and measurement of deposition offset. Calculated plasma temperatures and velocities are greater than 13,000 K and 2,000 m/s, respectively, in the vicinity of nozzle exit. For the plasma-particle momentum transfer, the drag coefficient was computed in two ways- with corrections accounting for the strongly varying plasma properties, and without these corrections. Calculated and experimental results, in respect to deposition offset, are in agreement to within 25% when calculated without varying properties corrections, and within about 40% with corrections; agreement in respect to average particle velocities is within 20% when calculated without varying properties corrections, and within the range 30–50% with corrections. 相似文献
2.
Various types of trimethylsilyl and tert-butyldimethylsilyl ethers of primary and secondary benzylic alcohols could be selectively converted to their corresponding carbonyl compounds with MnO2 in the presence of AlCl3 in good to excellent yields. 相似文献
3.
The Heck coupling of haloarenes with various alkenes was successfully performed in the presence of 0.5 mole % Pd(OAc)2 and 1.0 mole % d-glucosamine as an additive with K2CO3 as the optimal base in a mixture of H2O/iPrOH (φ r = 2: 1) as the reaction solvent at 80°C after 6 h. d-Glucosamine was found to be an inexpensive, air-stable, easy to available, and efficient additive in palladium-catalyzed Heck reactions of aryl iodides (67–95 % conversion) and bromides (38–72 % conversion). 相似文献
4.
Nasrollah Etemadi 《Journal of multivariate analysis》1977,7(2):249-264
The collision problems of two-parameter random walks are studied. That is, some criteria have been established in terms of the characteristic functions of two or more mutually independent random walks in order to determine if they meet infinitly often in certain restricted time sets. 相似文献
5.
A Fourier series method for finding the low-lying eigenfunctions and eigenvalues of the Schrödinger equation for a particle on the surface of a torus is given. 相似文献
6.
Bijan Etemadi Abdol Abadi Rex A. Palmer Brian W. Fitzsimmons 《Journal of chemical crystallography》1988,18(1):35-53
The crystal structure of bis (NN-di(n-propyl)dithiocarbamato iron(III) iodide, FeIII(S2CN6H14)2I, has been determined by the heavy-atom method and refined toR=0.055 for 3487 reflections withI(hkl)>3I(hkl). The crystals are triclinic,C¯1,Z=8,a=27.644(6),b=19.186(4),c=8.694(2) Å,=87.79(1),=88.72(1), =101.87(2)°. The I-Fe bond lengths are different in the two moleculesA andB in the asymmetric unit, having values of 2.642 Å (2.655) and 2.612 Å (2.634) respectively (libration-corrected values given in parentheses). The measured effective magnetic moment
eff3.89 BM, independent of temperature (93-353K), suggests a spinS of 3/2 with three unpaired electrons for FeIII. 相似文献
7.
Summary Let {X
ij; i>0, j>0} be a double sequence of i.i.d. random variables taking values in the d-dimensional integer lattice E
d
. Also let
. Then the range of random walk {S
mn: m>0, n>0} up to time (m, n), denoted by R
mn
, is the cardinality of the set {S
pq: 0m, n). In this paper a sufficient condition in terms of the characteristic function of X
11 is given so that
a.s. as either (m, n) or m(n) tends to infinity. 相似文献
8.
Some new tetradentate ligands with a NNOS coordination sphere were prepared and their corresponding nickel(II) complexes were synthesized and characterized by elemental analysis, IR, 1H NMR, UV–Vis and mass spectrophotometry. The thermodynamic formation constants of the complexes were measured spectrophotometrically, at a constant ionic strength of 0.1 M (NaClO4) at 25 °C in DMF solvent. The trend of the complex formation for nickel is as follows: 相似文献
9.
Bijan Etemadi Abdol Abadi David S. Moss Rex A. Palmer 《Journal of chemical crystallography》1984,14(3):269-281
The crystal structure of the versatile folk medicine berberine hydrogen sulfate, (C20H18NO4)+HSO
4
–
, has been determined by the heavy-atom method and refined by blocked full-matrix least-squares refinement. The crystals are triclinic, space groupF¯1,a=20.370(5),b=7.435(2),c=27.427(6) Å,=97.700(9),=116.222(9),=85.456.(8)°,Z=8,D
x
=1.556 g cm–3,D
m
=1.549(5) g cm–3. The structure refined toR=0.070 for 1659 observed reflections withI(hkl)2.5[I(hkl)]. The ring system of the berberine molecule is approximately planar, with both –OCH3 groups twisted slightly out of the plane. Heterocyclic ringB has a half-chair conformation with a pseudo-two-fold axis bisecting the bonds C(9)-C(10) and C(7)-C(8), diagonal to the isoquinoline groupAB. The five-membered ringE has an envelope conformation, the apical atom C(1) being out of plane. 相似文献
10.
In spite of the fact that the tail -algebra of a sequence of pairwise independent random variables may not be trivial, we have discovered that if such a sequence converges in probability or almost everywhere, then the limit has to be a constant. This enables us to provide necessary and sufficient conditions for its convergence, in terms of its marginal distribution functions.