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61.
Stephen G. Davies Rosemary Huckvale Thomas J.A. Lorkin Paul M. Roberts James E. Thomson 《Tetrahedron: Asymmetry》2011,22(14-15):1591-1593
A concise asymmetric synthesis of the gastroprokinetic agent (+)-(3S,4R)-cisapride {(+)-(3S,4R)-N(1)-[3′-(4″-fluorophenoxy)propyl]-3-methoxy-4-(2″′-methoxy-4″′-amino-5″′-chlorobenzamido)piperidine} from commercially available starting materials has been developed. The key step of this synthesis employs the diastereoselective conjugate addition of lithium (R)-N-benzyl-N-(α-methylbenzyl)amide to tert-butyl 5-[N-3′-(4″-fluorophenoxy)propyl-N-allylamino]pent-2-enoate and in situ enolate oxidation with (?)-camphorsulfonyloxaziridine to set the (3S,4R)-configuration found within the piperidine ring of the product. This synthesis proceeds in 9 steps from commercially available 1-(4′-fluorophenoxy)-3-bromopropane with an overall yield of 19%. 相似文献
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B. Batscha J. M. Kolthoff E. A. Pearson L. Cuny J. Golse und H. N. Thomson 《Fresenius' Journal of Analytical Chemistry》1933,94(1-2):44-46
Ohne Zusammenfassung 相似文献
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Simplified models have been used to simulate and study the flow-induced vibrations of the human vocal folds. While it is clear that the models' responses are sensitive to geometry, it is not clear how and to what extent specific geometric features influence model motion. In this study geometric features that played significant roles in governing the motion of a two-layer (body-cover), two-dimensional, finite element vocal fold model were identified. The model was defined using a flow solver based on the viscous, unsteady, Navier-Stokes equations and a solid solver that allowed for large strain and deformation. A screening-type design-of-experiments approach was used to identify the relative importance of 13 geometric parameters. Five output measures were analyzed to assess the magnitude of each geometric parameter's effect on the model's motion. The measures related to frequency, glottal width, flow rate, intraglottal angle, and intraglottal phase delay. The most significant geometric parameters were those associated with the cover--primarily the pre-phonatory intraglottal angle--as well as the body inferior angle. Some models exhibited evidence of improved model motion, including mucosal wave-like motion and alternating convergent-divergent glottal profiles, although further improvements are still needed to more closely mimic human vocal fold motion. 相似文献
69.
F. Migliorini K. A. Thomson G. J. Smallwood 《Applied physics. B, Lasers and optics》2011,104(2):273-283
The optical properties of soot, in particular the propensity of soot to absorb and scatter light as a function of wavelength,
are key parameters for the correct interpretation of soot optical diagnostics. An overview of the data available in the literature
highlights the differences in the reported optical properties of aging soot. In many cases, the properties of mature soot
are used when evaluating in-flame soot but this assumption might not be suitable for all conditions and should be checked.
This need has been demonstrated by performed spectral resolved line-of-sight attenuation (Spec-LOSA) measurements on an ethylene/air
premixed and non-premixed flame. Transmission electron microscopy of thermophoretically sampled soot was also performed to
qualify the soot aging and to establish soot morphology in order to correct light extinction coefficients for the scattering
contribution. The measured refractive index absorption function, E(m)
λ
, showed a very strong spectral dependence which also varied with height above the burner for both flames. However, above
700 nm, the slope of the refractive index function was near zero for both flames and all measurement heights. The upper visible
and near infrared wavelengths are therefore recommended for soot optical measurements. 相似文献
70.
M. Köhler K. P. Geigle W. Meier B. M. Crosland K. A. Thomson G. J. Smallwood 《Applied physics. B, Lasers and optics》2011,104(2):409-425
Computational fluid dynamics (CFD) modelers require high-quality experimental data sets for validation of their numerical
tools. Preferred features for numerical simulations of a sooting, turbulent test case flame are simplicity (no pilot flame),
well-defined boundary conditions, and sufficient soot production. This paper proposes a non-premixed C2H4/air turbulent jet flame to fill this role and presents an extensive database for soot model validation. 相似文献