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1.
A simple derivation of Vonnegut's equation for use in the determination of interfacial tension by the spinning drop technique is described. The derivation involves a cylindrical approximation and calculates the kinetic energy of rotation of the system from a consideration of its moment of inertia. 相似文献
2.
Cyclical bifurcated hydrogen bonded structures are proposed for aqueous solutions of hydrofluoric acid and for the bifluoride ion which are consistent with the spectral data. The structure proposed for HF is also applicable to solutions in organic solvents. Raman spectra of tetramethylguanidinium perchlorate suggest that the corresponding Raman spectra of perchloric acid solutions may not be interpreted in terms of a completely dissociated acid. Other evidence including activity coefficient, heat capacity and partial molal volume data suggest that there is some association in relatively dilute perchloric acid solutions between the perchlorate ion and the hydrated proton. This association decreases in concentrated aqueous solutions. 相似文献
3.
Relative apparent molal heat contents, φL, are reported for the tetramethylguanidinium salts of methanesulfonic (MS) and trifluoromethanesulfonic (TFMS) acids. Relative partial molal heat contents, L?2, are calculated and combined with previously reported activity coefficient data, to yield excess entropies. It is found that the values of L?2 make the principal contribution to the excess entropies of Me4GuMS solutions while the excess free energies, as calculated from activity coefficients, make the greatest contribution to the excess entropies of Me4GuTFMS solutions. 相似文献
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Dibenzobarrelenes have been prepared by the cycloaddition of benzyne to anthracenes. The first method gives complex mixtures from which only poor yields of 1, 4-adducts may be obtained,1 exceot wgeb tetragakivebztbes are enokited,2,3 Muller and Vergne have reported4 that dibenzobarrelene is formed by the reaction of acetylene with anthracene, but it may be significant that later workers have chosen to use either the above-mentioned benzyne route or a modification of the cycloaddition to anthracenne involving dichlorethylene followed by dechlorination to prepare the parent compound.5 Our approach to the synthesis of this ring system employs our previously described 1,2–photoaramatisation reactions.6 A significant feature of the present work is that it demonstrates that a photochemical reaction can be employed to generate compounds, in this case dibenzobarrelenes, known to be photolabile.7 相似文献
6.
Gareth AD Hardy Nesrina Imami Mark R Nelson Ann K Sullivan Ron Moss Marlén MI Aasa-Chapman Brian Gazzard Frances M Gotch 《Journal of immune based therapies and vaccines》2007,5(1):6-12
Background
Fully functional HIV-1-specific CD8 and CD4 effector T-cell responses are vital to the containment of viral activity and disease progression. These responses are lacking in HIV-1-infected patients with progressive disease. We attempted to augment fully functional HIV-1-specific CD8 and CD4 effector T-cell responses in patients with advanced chronic HIV-1 infection. 相似文献7.
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