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111.
Edouard Demole 《Helvetica chimica acta》1969,52(7):2065-2085
The stereospecific syntheses of the eleven racemic 2,2, exo-3-trimethyl-exo-5-norbornyl-cyclohexanols related to the formula VI have been achieved. Moreover, the fragrant properties of these isomeric and stereomeric cyclohexanols have been carefully estimated by a team of four well-experienced perfumers. In good agreement with our earlier observations [1 ab], it was concluded that the axial 3-(2,2, exo-3-trimethyl-exo-5-norbornyl)-cyclohexanols, threo (XXIV) and erythro (XXIX), are the only isomers which display a very powerful and genuine sandalwood odour. The other cyclohexanols were found to be about 20–100 times less fragrant (4 compounds), or practically odourless (5 compounds). 相似文献
112.
Investigation by gas liquid chromatography of a small but organoleptically typical subfraction of Oriental tobacco condensate led to the identification of 47 compounds. Of these 21 have hitherto not been reported as Oriental tobacco constituents, and 14 appear to be novel to all tobacco types. The latter are (E)-3-methyl-non-2-en-4-one ( 1 ), (E)-1-(2, 3, 6-trimethylphenyl)-but-2-en-1-one ( 3 ), pentadecan-15-olide ( 12 ), 8α, 13:9α, 13-diepoxy-15, 16-dinorlabdane ( 17 ), (Z)-octadec-9-en-18-olide ( 18 ), (E)-2-ethylidene-6, 10, 14-trimethylpentadecanal ( 21 ), the norlabdanoids 9 , 10 , 11 , 14 , 15 , 16 , tridecan-2-one, and 2-phenylethyl isovalerate. The macrolides 12 and 18 represent the first musk compounds detected in tobacco. Identification were made by direct comparison (MS. and/or 1 H-NMR./IR.) with the authentic chemicals synthesized whenever necessary. 相似文献
113.
Number theorists have studied extensively the connections between the distribution of zeros of the Riemann ζ-function, and
of some generalizations, with the statistics of the eigenvalues of large random matrices. It is interesting to compare the
average moments of these functions in an interval to their counterpart in random matrices, which are the expectation values
of the characteristic polynomials of the matrix. It turns out that these expectation values are quite interesting. For instance,
the moments of order 2K scale, for unitary invariant ensembles, as the density of eigenvalues raised to the power K
2; the prefactor turns out to be a universal number, i.e. it is independent of the specific probability distribution. An equivalent
behaviour and prefactor had been found, as a conjecture, within number theory. The moments of the characteristic determinants
of random matrices are computed here as limits, at coinciding points, of multi-point correlators of determinants. These correlators
are in fact universal in Dyson's scaling limit in which the difference between the points goes to zero, the size of the matrix
goes to infinity, and their product remains finite.
Received: 1 October 1999 / Accepted: 18 May 2000 相似文献
114.
David Sedarsky Megan Paciaroni Edouard Berrocal Per Petterson Joseph Zelina James Gord Mark Linne 《Experiments in fluids》2010,49(2):391-408
We have applied three different imaging diagnostics: particle imaging velocimetry, high-speed shadowgraphy, and ballistic
imaging, to observe the breakup of a liquid jet in a crossflow of air under a variety of conditions. The experimental system
was designed to provide well-controlled conditions with minimal amounts of turbulence in the liquid jet and the gaseous crossflow.
A variety of Weber numbers and momentum flux ratios were studied in order to provide a sizable data set for the validation
of computational models. This paper briefly describes the three spray imaging techniques, outlines the results obtained to-date,
and tabulates image statistics for each of ten spray conditions at varying distances from the spray nozzle orifice. The end
result is a first installment in what will become a comprehensive model validation data set for jets in crossflow for use
by computational fluid dynamics modelers. 相似文献
115.
Claude Moulis Edouard Stanislas Jean-Claude Rossi 《Magnetic resonance in chemistry : MRC》1978,11(8):398-400
The four pseudoprotoberberins extracted from Isopyrum thalictroides L. were reduced with sodium borohydride to the corresponding tetrahydropseudoprotoberberins. Comparison between the 13C NMR spectra of these and of synthetic protoberberins allowed us to assign a trans-1 configuration to the four reduced alkaloids and also to provide for this particular configuration an unequivocal criterion for the differentiation (based on the chemical shift of C-8) between tetrahydroprotoberberins (9, 10 substituted) and tetrahydropseudoprotoberberins (10, 11 substituted). 相似文献
116.
117.
O. Pepin N. Thuaud B. Sebille L. Edouard N. Lemort J. -L. Beaumont 《Chromatographia》1982,16(1):267-270
Summary Immunoglobulins have been extracted from human and rabbit serum by size exclusion high performance liquid chromatography. In the case of rabbit immunized against ethinyl-oestradiol and woman having arterial thrombosis in the course of oral contraceptive use, the extracted immunoglobulins present a very high affinity for 17 -oestradiol sulphate. The measurement of affinity to this compound of different extracted immunoglobulins allows a quantitative determination of these specific proteins. Comparative studies with radioimmunoassays are in good agreement.Presented at the 14th International Symposium on Chromatography London, September, 1982 相似文献
118.
Gas liquid chromatography allowed isolation of the novel cis-2-isopropenyl-8-methyl-1,2,3,4-tetrahydro-1-naphthalenol ( A ) and its dehydration product, 3-isopropenyl-5-methyl-1,2-dihydronaphthalene ( B ), from two small subfractions of Virginia tobacco condensate. Both these norsesquiterpenes were identified on spectral grounds and synthesized from 1-methylnaphthalene in a way (9 steps) that also afforded the «non-natural», trans-alcohol A ′. The possible biogenesis of A and B in tobacco is briefly outlined. 相似文献