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461.
R. Contreras G.G. Elliot R.O. Gould G.A. Heath A.J. Lindsay T.A. Stephenson 《Journal of organometallic chemistry》1981,215(1):C6-C10
Several isomers of the type [M2Cl5L4] (M = Ru, L = AsPh3, As(p-tol)3, As(p-PhCl)3, PEt2Ph, PMe2Ph; L2 = Ph2As(CH2)2AsPh2; M = Os, L = PPh3, AsPh3) have been synthesised by various routes and characterised by magnetic, ESR and electrochemical measurements, and for [(PEt2Ph)Cl2RuCl3Ru(PEt2Ph)3] by X-ray structural analysis. 相似文献
462.
Benzonitrile reduces the rate of alkyne hydrogenation. However, it enhances the rate of styrene hydrogenation while reducing the rate of -methylstyrene hydrogenation. 相似文献
463.
Hong Sp SP Lindsay HA Yaramasu T Zhang X McIntosh MC 《The Journal of organic chemistry》2002,67(7):2042-2055
A variety of bis-allylic esters were prepared by vinylmetal addition to cycloalkenones followed by esterification either in situ or in a separate operation. For chiral cyclohexenones, the vinyl additions generally occurred with >10:1 diastereoselectivity. Although in some cases the bis-allylic esters proved to be sensitive to silica gel or other adsorbents, all of the esters examined could be isolated in acceptable purity. The Ireland-Claisen rearrangement of the bis-allylic esters occurred with complete regioselectivity via the exocyclic alkene. The alkene stereochemistry and the stereochemistry at C-2 and C-3 of the pentenoic acid products were consistent with a chairlike transition state in the rearrangement. Substituents at the carbons adjacent to the allylic carbinol carbon (i.e., C-2 or C-6 in cyclohexenone-derived substrates) directed the stereochemical course of the rearrangement. The rearrangements generally proceeded so as to place the larger of the C-2 or C-6 substituents in the pseudoequatorial position with respect to the chairlike transition state. For a bis-allylic ester bearing both a C-2-CH(3) and a C-6-OMEM substituent, the rearrangement product resulted from the nominally smaller OMEM substituent occupying a pseudoequatorial position with respect to the chairlike transition state. 相似文献
464.
Lindsay E. Roy 《Journal of solid state chemistry》2007,180(3):818-823
Spin-dependent extended Hückel tight binding (EHTB) calculations were carried out for the magnetic solid Gd2S3 by considering 20 different variations in the ordering of the 4f7 moments. The tight-binding calculations are used to interpolate the band structure of a nonmagnetic congener (Y2S3) and the 4f/5d,6s exchange interactions are introduced as perturbations via the introduction of spin-dependent Hdd and Hss parameters. The calculations predict that Gd2S3 adopts an antiferromagnetic ordering of the 4f7 moments that is consistent with published neutron diffraction results. Our attempt to account for the calculated energies of the spin patterns using an Ising model was unsuccessful. 相似文献
465.
466.
On quantum stochastic differential equations 总被引:1,自引:0,他引:1
J. Martin Lindsay Adam G. Skalski 《Journal of Mathematical Analysis and Applications》2007,330(2):1093-1114
Existence and uniqueness theorems for quantum stochastic differential equations with nontrivial initial conditions are proved for coefficients with completely bounded columns. Applications are given for the case of finite-dimensional initial space or, more generally, for coefficients satisfying a finite localisability condition. Necessary and sufficient conditions are obtained for a conjugate pair of quantum stochastic cocycles on a finite-dimensional operator space to strongly satisfy such a quantum stochastic differential equation. This gives an alternative approach to quantum stochastic convolution cocycles on a coalgebra. 相似文献
467.
Lavictoire LA Snyder J Stoolmiller M Hollenstein T 《Nonlinear dynamics, psychology, and life sciences》2012,16(3):293-312
In interpersonal interaction research, moving beyond dyadic to triadic dynamics can be analytically daunting. We explored the affective states expressed during triadic peer interactions to understand how patterns were associated with childhood psychopathology and sociometric status. High-risk kindergarten children (N = 216) were observed in several groups of three during a free play task. We extended the state space grid technique to 3-dimensional analysis in order to derive variables of interest. Unlike results from parent-child dyadic interactions, triadic affective variability was not strongly associated with externalizing or internalizing problems. However, several triadic affective states were distinguished by externalizing, internalizing, and sociometric status, most commonly mutually aversive affect. Strengths and limitations of this methodology in relation to understanding peer triadic interactions are discussed. 相似文献
468.
The aim of this study was to investigate the utility of the water T(2) values of malignant breast lesions in predicting response after the first and second cycles of neoadjuvant chemotherapy (NAC), both alone and in combination with lesion volumes. Thirty-five patients were scanned before the commencement of chemotherapy and again after the first, second and final treatment cycles. Two methods of obtaining lesion T(2) were used: imaging, where a series of T(2)-weighted images was acquired (T(R)/T(E)=1000/30, 60, 90 and 120 ms), and spectroscopy, where the T(2) value of unsuppressed water signal was determined with a multiecho sequence (T(R)=1.5 s; initial T(E)=35 ms; 64 steps of 2.5 ms; 2 unsuppressed acquisitions per T(E)). Lesion volumes were computed from contrast-enhanced 3D fat-suppressed images. The study found that, using the imaging method of obtaining T(2), the ratio of the product of lesion T(2) and volume after the second cycle of NAC to pretreatment value is a good predictor of ultimate lesion response, defined as a > or =65% reduction in tumor volume after the final treatment cycle, with positive and negative predictive values of 95.5% and 84.6%, respectively. 相似文献
469.
[reaction: see text] Trifluoroacetic acid mediates the hydroarylation of alkenes to afford dihydrocoumarins and dihydroquinolones in good yield. Intermolecular hydroarylation of cinnamic acids by phenols is particularly facile, which leads to the conclusion that previous reports of palladium-catalyzed hydroarylation of cinnamic acids in trifluoroacetic acid are erroneous. 相似文献
470.