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21.
Symmetric and unsymmetric divinylic sulfides can be prepared almost quantitatively by the elimination of HI by base from the corresponding α,α′-diiodosulfide. These molecules are quantitatively formed in situ from α,α′-trimethylsilosulfides and iodotrimethylsilane under mild conditions. 相似文献
22.
An optically active, axially chiral NAD model compound(1) with a quinoline ring system was reduced by the chiral NADH model compound (4), affording a mixture of 1,2- and 1,4-dihydroquinolines. The carbonyl orientation governs the molecular arrangement in the transition state of the reaction and determines the regio- and enantioselectivity of the product. 相似文献
23.
We have observed lasing in a complicated eigenmode of a quasi-stadium laser diode with an unstable resonator consisting of two curved end mirrors obeying an unstable resonator condition and two straight sidewall mirrors. The laser was fabricated by application of a reactive-ion-etching technique to a molecular beam epitaxy-grown graded-index separate-confinement heterostructure single-quantum-well GaAs/AlGaAs structure. The far-field pattern shows that the lasing mode corresponds to the complicated lowest-loss mode obtained numerically by an extended Fox-Li method. 相似文献
24.
A cyclic dimer of chiral saddle-shaped porphyrin with p-xylylene linkers, upon interaction with mandelic acid, showed an enhanced circular dichroism activity, which was more than 7 times as large as that of a monomeric reference. 相似文献
25.
This paper reports the important effects of frequency-locking in an electro-optical bistable system with long delay. The mechanism of the locking behaviour is discussed from the viewpoint of power spectrum and the linear eigen modes of the system. 相似文献
26.
Aida Toma 《Rendiconti del Circolo Matematico di Palermo》2009,58(1):29-40
This paper proves a new integral representation theorem for powers of elements in locally m-convex algebras. It is shown that the conditions handled in this theorem are satisfied for any sequentially complete locally
m-convex Q-algebra. Various applications of this result concerning the spectrum, the spectral radius or the numerical radius are given.
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29.
Daroui-Mokaddem H Kabouche A Bouacha M Soumati B El-Azzouny A Bruneau C Kabouche Z 《Natural product communications》2010,5(10):1669-1672
The essential oils of fresh leaves of Eucalyptus globulus L. (Myrtaceae), and leaves and stems of Smyrnium olusatrum L. (Apiaceae), obtained by hydrodistillation in a Clevenger-type apparatus, were analyzed by GC/MS. Twenty compounds were characterized, representing 98.3% of the essential oil of E. globulus, with 1,8-cineole (48.6%), globulol (10.9%), trans-pinocarveol (10.7%), and alpha-terpineol (6.6%) as main components, while thirty-three compounds were characterized, representing 94.3% of the essential oil of S. olusatrum, with sabinene (27.1%), curzerene (13.7%), methyl-1-benzyl-2-oxocyclooctane carboxylate (12.3%), alpha-pinene (7.2%), cryptone (7.1%) and beta-pinene (5.7%) as the major components. The essential oils of E. globulus and S. olusatrum were tested against a wide range of fungal and bacterial strains. Both oils showed significant antimicrobial activity. 相似文献
30.
Aida Toma 《Comptes Rendus Mathematique》2013,351(7-8):311-316
We consider new classes of estimators and test statistics for models satisfying linear constraints with unknown parameter. These procedures are based on minimization of divergences through duality techniques. We prove that, for various divergences, the new approach provides robust estimation and test procedures, unlike the empirical likelihood method. We give general results using the influence function approach, which we exemplify in detail in the case of the Cressie–Read divergences. It is found that the Hellinger distance is one of the divergences that leads to robust procedures. 相似文献