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431.
[reaction: see text] A carbamoylsilane is shown to carry out the direct carbamoylation of aryl chlorides, bromides, and iodides under catalysis by phosphinepalladium(0) complexes. 相似文献
432.
A. A. Sen Indrajit Chakrabarty T. R. Seshadri 《General Relativity and Gravitation》2002,34(4):477-490
We have investigated cosmological models with a self-interacting scalar field and a dissipative matter fluid as the sources of matter. Different variables are expressed in terms of a generating function. Exact solutions are obtained for one particular choice of the generating function. The potential corresponding to this generating function is a standard tree-level potential arising in the perturbative regime in quantum field theory. With suitable choice of parameters, the scale factor in our model exhibits both decelerating behaviour in the early time as well as an accelerating phase at late times. For certain choices of the parameter the solution also exhibits an attractor nature towards an asymptotic de-Sitter universe. 相似文献
433.
Alkenyl chlorides and bromides are converted into tertiary enamides by treatment with a carbamoylsilane in toluene at 110 degrees C in the presence of phosphine-palladium(0) catalysts. [reaction: see text] 相似文献
434.
Using a gauge-invariant characterization of monopoles defined via their centres, we investigate the generic topological field
pattern for the three-dimensional Yang-Mills theory. This leads to field patterns with one-half winding number. After presenting
the main features through the simpler case of half-vortices, we consider half-monopoles in detail. 相似文献
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437.
An aqueous solution of gelatin binds silver(I) at pH >7 and a yellow silver sol can be produced from this by reduction. The sol reacts with peroxide in strongly ammoniacal medium to give a colourless solution. The reaction may be used for photometric and visual titration of peroxide with relative standard deviations of 0.4 and 1.5% respectively and also for its spectrophotometric determination. 相似文献
438.
Maity Debayan San Martín Jorge Takahashi Takéo Tucsnak Marius 《Journal of Nonlinear Science》2019,29(5):1975-2020
Journal of Nonlinear Science - We study the interaction of surface water waves with a floating solid constraint to move only in the vertical direction. The first novelty we bring in is that we... 相似文献
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440.
Bhaumik C Das S Maity D Baitalik S 《Dalton transactions (Cambridge, England : 2003)》2012,41(8):2427-2438
Homo- and heteroleptic bis-tridentate ruthenium(II) and osmium(II) complexes of compositions [(tpy-PhCH(3))Ru(tpy-HImzPh(3))](ClO(4))(2) (1), [(H(2)pbbzim)Ru(tpy-HImzPh(3))] (ClO(4))(2) (2) and [M(tpy-HImzPh(3))(2)](ClO(4))(2) [M = Ru(II) (3) and Os(II) (4)], where tpy-PhCH(3) = p-methylphenyl terpyridine, H(2)pbbzim = 2,6-bis(benzimidazole-2-yl)pyridine and tpy-HImzPh(3) = 4'-[4-(4,5-diphenyl-1H-imidazol-2-yl)-phenyl]-[2,2':6',2']terpyridine, have been synthesized and characterized by using standard analytical and spectroscopic techniques. These compounds were designed to increase the room temperature excited-state lifetimes of bisterpyridine-type ruthenium(II) and osmium(II) complexes. The X-ray crystal structures of two homoleptic complexes 3 and 4 have been determined and show that both the compounds crystallized in orthorhombic form with space group Fddd. The photophysical and redox properties of the complexes have been thoroughly investigated. All the complexes display moderately strong luminescence at room temperature with lifetimes in the range of 6-35 ns. The complexes are found to undergo one reversible oxidation in the positive potential window (0 to +1.6 V) and one irreversible and two successive quasi-reversible reductions in the negative potential window (0 to -2.0 V). The influence of solvents on the photophysical properties of the complexes has also been investigated in detail. 相似文献