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171.
We characterise all maximal convex l-subgroups of A(), the automorphismgroup of a doubly transitive chain of countable coterminality.We then determine, up to isomorphism, all doubly transitiveactions of the l-group A(). Finally, assuming the ContinuumHypothesis, we show that there exists an unbounded chain ofproper prime subgroups of A(). 相似文献
172.
Appropriate oxygen-18 labeling experiments demonstrate that N,O-diarylhydroxylamines do not undergo solvolysis the reversible formation of ion pairs. This is in total conflict with the conclusions from previous indirect kinetic studies of these ultimate carcinogen models. 相似文献
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Richard E. Robertson Catherine W. Joynson 《Journal of Polymer Science.Polymer Physics》1968,6(9):1673-1681
To learn more about the out-of-plane deformation of polymer lamellae during drawing, we have measured the resistance to shear along various planes in uniaxially oriented polyethylene and polypropylene. Fissures parallel to the orientation axis in oriented materials always cause too small an experimental value for the resistance of crystal glide parallel to the chain axes, but a rough estimate for the resistance to crystal glide is obtained using the elastic anisotropy. Also, the results suggest that kinking can be easier than glide when glide is inhibited by tie molecules. 相似文献
175.
Masato Hasebe Catherine Lazare Paul de Mayo Alan C. Weedon 《Tetrahedron letters》1981,22(51):5149-5152
Irradiation of a number of aromatic hydrocarbons adsorbed on alumina in the presence of ferric chloride leads to monochlorination. 相似文献
176.
Douglas J. Raber Milton D. Johnston Catherine M. Campbell Christopher M. Janks Pamela Sutton 《Magnetic resonance in chemistry : MRC》1978,11(7):323-328
The use of lanthanide shift reagents (LSR's) to obtain additional structural information from nuclear magnetic resonance studies has gained widespread acceptance. However, there has not been general agreement with regard to the most appropriate methodology for analysis of the shifted NMR spectra. We present arguments that only the bound shifts (Δ1) corresponding to the LS complex should be used for correlation of lanthanide-induced shifts with molecular structure by means of the pseudocontact equation. Several examples are discussed of compounds for which the relative induced shifts are dependent on the concentration of LSR. For such cases it is not possible for both Δ1 and Δ2 (the bound shift corresponding to the LS2 complex) to correlate successfully with the correct structure. Alternative methods of obtaining bound shifts are critically evaluated. 相似文献
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Chow HS Constable EC Housecroft CE Kulicke KJ Tao Y 《Dalton transactions (Cambridge, England : 2003)》2005,(2):236-237
Electron exchange between [Co(terpy)2]3+ and [Co(terpy)2]2+ can be monitored by 1H NMR exchange spectroscopy and allows the cobalt(II) spectra to be fully assigned. 相似文献