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961.
Wang Y Xie Y Wei P King RB Schaefer HF Schleyer Pv Robinson GH 《Journal of the American Chemical Society》2008,130(45):14970-14971
The potassium graphite reduction of L:PCl3 leads to the formation of carbene-stabilized diphosphorus molecules, L:P-P:L, 1 (L: = :C{N(2,6-Pri2C6H3)CH}2) and 2 (L: = :C{N(2,4,6-Me3C6H2)CH}2), respectively. The nature of the bonding in 1 and 2 was delineated by DFT computations. 相似文献
962.
Brian K. Nicholson J. Scott McIndoe Dore Augusto Clemente Ward T. Robinson 《Structural chemistry》2008,19(3):489-492
There are two molecules in the asymmetric unit of the P21/c unit cell of ClCH2Mn(CO)5, the first halomethyl complex of manganese to be structurally determined. The molecules are crystallographically independent, despite an apparent local centre of symmetry. The average bond parameters include Mn–Calkyl 2.128(8) Å, C–Cl 1.811(8) Å and Mn–C–Cl 116.4(4)°. 相似文献
963.
The biosynthesis of the vancomycin aglycone involves three oxidative phenol coupling reactions, each catalyzed by a discrete cytochrome P450-like enzyme. Studies on the mechanism and specificity of the enzyme (called OxyB) catalyzing the first coupling, require access to suitable linear peptide precursors, each conjugated as a thioester to a peptide carrier domain of the vancomycin non-ribosomal peptide synthetase. An efficient route to representative free linear peptides is described here. The method makes use of Alloc-chemistry during solid-phase assembly of the peptide backbone, but importantly and in contrast to earlier efforts, largely avoids the use of amino acid side chain protecting groups. In this way, the target linear peptides can be released directly from the solid support under very mild conditions. 相似文献
964.
Study of three-dimensional structure in wire-array z pinches by controlled seeding of axial modulations in wire radius 总被引:1,自引:0,他引:1
Jones B Deeney C McKenney JL Garasi CJ Mehlhorn TA Robinson AC Wunsch SE Bland SN Lebedev SV Chittenden JP Bott SC Ampleford DJ Palmer JB Rapley J Hall GN Oliver BV 《Physical review letters》2005,95(22):225001
Three-dimensional perturbations have been seeded in wire-array z pinches by etching 15 microm diameter aluminum wires to introduce 20% modulations in radius with a controlled axial wavelength. These perturbations seed additional three-dimensional imploding structures that are studied experimentally and with magnetohydrodynamics calculations, highlighting the role of current path nonuniformity in perturbation-induced magnetic bubble formation. 相似文献
965.
We theoretically demonstrate a mechanism for reduction of mode volume in high index contrast optical microcavities to below a cubic half wavelength. We show that by using dielectric discontinuities with subwavelength dimensions as a means of local field enhancement, the effective mode volume (V(eff)) becomes wavelength independent. Cavities with V(eff) on the order of 10(-2)(lambda/2n)(-3) can be achieved using such discontinuities, with a corresponding increase in the Purcell factor of nearly 2 orders of magnitude relative to previously demonstrated high index photonic crystal cavities. 相似文献
966.
967.
Derek W. Robinson 《Communications in Mathematical Physics》1976,50(1):53-59
The phenomena of Bose-Einstein condensation is discussed for particles in a box with attractive walls. Variation of the elasticity has the following effects, a) the critical temperature, fugacity, etc. vary, b) separation of phases occurs, c) condensation in one and two dimensions is possible. 相似文献
968.
Aequationes mathematicae - 相似文献
969.
M.J.T. Robinson 《Tetrahedron》1974,30(13):1971-1978
970.
Abraham Robinson 《Journal of Combinatorial Theory, Series A》1973,14(3):324-333
We introduce the abstract notion of an ordered differential field and show that some of the basic asymptotic growth properties of differentiable functions can be discussed within this setting. However, in order to ensure that log x → ∞ as x → ∞, we have to assume that the field of constants is archimedean. 相似文献