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161.
Kazuhiko Orito Harumi Kaga Mitsuomi Itoh S. Osmund De Silva Richard H. Manske Russel Rodrigo 《Journal of heterocyclic chemistry》1980,17(3):417-423
Aromatic methoxy and/or methylenedioxy substituted 7-methyltetrahydrobenz[d]indeno[1,2-b]-azepines 7 and their 12-oxo derivatives 8 were efficiently synthesized by the general method consisting of two types of intramolecular dehydrative cyclizations, as follows. N-Methyl-N-β-phenethylacetamides 1 were cyanomethylated in the two-step process of chloromethylation and treatment of the resultant benzyl chlorides with sodium cyanide. The condensation of the benzyl cyanides 2 with the appropriate benzaldehydes, followed by reduction of the benzylidene function, gave α,β-diphenylpropionitriles 3 . Successively, hydrolysis to the amino acids 4 and the thermal cyclization converted 3 to the benzylbenzazepinones 5 , which were also prepared by benzylation of the benzazepinones 6 smoothly by heating of 5 with phosphoryl chloride to afford the title azepines 7 . Further, these tetracyclic enamines 7 underwent autoxidation to the corresponding 12-oxo derivatives 8 , on exposure to oxygen in the presence of Triton B. 相似文献
162.
Rodrigo P. Gomez 《manuscripta mathematica》1997,93(1):325-335
In this article we study the behavior of harmonic maps from compact connected Lie groups with bi-invariant metrics into a
Hilbert orthogonal group. In particular, we will demonstrate that any such harmonic map always has image contained within
someO(n),n<∞. Since homomorphisms are a special subset of the harmonic maps we get as a corollary an extension of the Peter-Weyl theorem,
namely, that every representation of a connected compact Lie group is finite dimensional.
This article was processed by the author using the LATEX style filecljour1 from Springer-Verlag. 相似文献
163.
The behavior of single silicon adatoms on the W {110} plane has been successfully studied for the first time. Single atom diffusion parameters are found to be Ed = 0.70 ± 0.07 eV, and . The field desorption behavior of Si atoms is similar to that of metal adatoms. SiSi adatom-adatom interaction shows nonmonotonic distance dependence, but the repulsive region around 3.2 Å is much weaker than those found in metal adatom interactions. 相似文献
164.
Söderlind F Pedersen H Petoral RM Käll PO Uvdal K 《Journal of colloid and interface science》2005,288(1):140-148
Nanocrystals of Gd2O3 have been prepared by various methods, using, e.g., trioctylphosphine oxide (TOPO), diethylene glycol (DEG) or glycine. The crystalline particles were of sizes 5 to 15 nm. Different carboxylic acids, e.g., oleic acid or citric acid, were adsorbed onto the surface of the particles made with DEG. IR measurements show that the molecules coordinate to the Gd2O3 surface via the carboxylate group in a bidentate or bridging manner. The organic-acid/particle complexes were characterised by XRPD, TEM, FTIR, Raman, and XPS. 相似文献
165.
José Marí a Martell Carlos Pé rez Rodrigo Trujillo-Gonzá lez 《Transactions of the American Mathematical Society》2005,357(1):385-396
We show that the classical Hörmander condition, or analogously the -Hörmander condition, for singular integral operators is not sufficient to derive Coifman's inequality
where , is the Hardy-Littlewood maximal operator, is any weight and is a constant depending upon and the constant of . This estimate is well known to hold when is a Calderón-Zygmund operator.
where and where is an arbitrary weight. However, by a recent result due to A. Lerner, this inequality is satisfied whenever is a Calderón-Zygmund operator.
where , is the Hardy-Littlewood maximal operator, is any weight and is a constant depending upon and the constant of . This estimate is well known to hold when is a Calderón-Zygmund operator.
As a consequence we deduce that the following estimate does not hold:
where and where is an arbitrary weight. However, by a recent result due to A. Lerner, this inequality is satisfied whenever is a Calderón-Zygmund operator.
One of the main ingredients of the proof is a very general extrapolation theorem for weights.
166.
We present a new identity involving compositions (i.e., ordered partitions of natural numbers). The formula has its origin
in complex dynamical systems and appears when counting, in the polynomial family
periodic critical orbits with equivalent itineraries. We give two different proofs of the identity; one following the original
approach in dynamics and another with purely combinatorial methods.
Received October 1, 2004 相似文献
167.
Rodrigo Medina 《Physics letters. A》1979,70(3):227-230
A relation is found between the time-dependent susceptibility of the Edwards-Anderson spin glass model and the spin self-correlation. The relation is explicitly proved to hold for Monte Carlo simulations of the model. The susceptibility peaks found in Monte Carlo calculations are discussed. 相似文献
168.
Palacios RE Kodis G Herrero C Ochoa EM Gervaldo M Gould SL Kennis JT Gust D Moore TA Moore AL 《The journal of physical chemistry. B》2006,110(50):25411-25420
Two artificial photosynthetic antenna models consisting of a Si phthalocyanine (Pc) bearing two axially attached carotenoid moieties having either 9 or 10 conjugated double bonds are used to illustrate some of the function of carotenoids in photosynthetic membranes. Both models studied in toluene, methyltetrahydrofuran, and benzonitrile exhibited charge separated states of the type C*+-Pc*- confirming that the quenching of the Pc S1 state is due to photoinduced electron transfer. In hexane, the Pc S1 state of the 10 double bond carotenoid-Pc model was slightly quenched but the C*+-Pc*- transient was not spectroscopically detected. A semiclassical analysis of the data in hexane at temperatures ranging from 180 to 320 K was used to demonstrate that photoinduced electron transfer could occur. The model bearing the 10 double bond carotenoids exhibits biexponential fluorescence decay in toluene and in hexane, which is interpreted in terms of an equilibrium mixture of two isomers comprising s-cis and s-trans conformers of the carotenoid. The shorter fluorescence lifetime is associated with an s-cis carotenoid conformer where the close approach between the donor and acceptor moieties provides through-space electronic coupling in addition to the through-bond component. 相似文献
169.
In this article we study the phase transition phenomenon for the Ising model under the action of a non-uniform external magnetic field. We show that the Ising model on the hypercubic lattice with a summable magnetic field has a first-order phase transition and, for any positive (resp. negative) and bounded magnetic field, the model does not present the phase transition phenomenon whenever lim?inf?h i >0, where \(\mathbf{h}=(h_{i})_{i\in \mathbb{Z}^{d}}\) is the external magnetic field. 相似文献
170.
This paper discloses results of measuring the effective radiating area (AER) and the beam non-uniformity ratio (RBN) for US transducers at 5.0 MHz. Measurements were carried out at Laboratory of Ultrasound of the Brazilian National Institute of Metrology, Standardization, and Industrial Quality. As reliability proof of system’s adequacy, uncertainties were assessed. The calculation protocol was developed based on standard IEC 61689:2007. Type A uncertainty was estimated after four repetitions of the full procedure for the determination of AER and RBN, and Type B uncertainty was estimated from the mathematical model for both calculations, obtained from IEC 61689:2007 and the guide to the expression of uncertainty in measurement. The procedure presented herein represents the state of the art regarding metrology for testing therapeutic ultrasound devices, and its application results in fundamental aspects to support their evaluation regarding quality assurance, for instance, for a certification process due safety and performance. 相似文献