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81.
Condensation products obtained from the treatment of uracil amidine with preformed or in situ generated suitably substituted
olefins unexpectedly undergo intramolecular cyclisation during silica gel chromatography to generate pyrido[2,3-d]pyrimidines. Various reaction conditions are studied and the altered nature of the uracil amidine molecule is further explored
by reacting it with different suitably substituted alkenes. 相似文献
82.
E. Tchomgo Felenou P. Tchofo Dinda C.M. Ngabireng K. Nakkeeran 《Physics letters. A》2013,377(10-11):770-777
We consider optical waveguides in which light pulses may execute complex dynamical behaviors including translational motions accompanied with strong internal vibrations. Such systems necessarily generate various types of collective motion, in which each collective mode is describable by a collective coordinate. We present a novel projection operator formalism for deriving the equations of motion of the collective coordinates and coupled fields. This formalism is built up by treating separately the dynamics of the pulse phase and that of its amplitude, that is, by using two distinct projection operators (one for the amplitude, and the other one for the phase). This new pair of operators, which we call reduced projection operators, has as main virtue of having dimension reduced by half as compared to that of the conventional operators that includes both pulse amplitude and phase together. The main interest of the reduced projection operators lies in the ease with which the equations of motion are derived when compared with the amount of algebra needed to obtain the same equations from the conventional projection operators. We provide examples of concrete situations that illustrate the effectiveness of the collective-coordinate approach based on the reduced projection operators. 相似文献
83.
84.
A new 14-membered macrocyclic ligand, 5,7,12,14-dibenzo-2,3,9,10-tetraoxa-1,4,8,11-tetraazacyclotetradecane and a 16-membered ligand, 6,8,14,16-dibenzo-4,12-dimethyl-2,10-diphenyl-1,5,9,13-tetraazacyclohexadeca-1,5,9,12-tetra-ene and their transition metal complexes were prepared by the template method and characterized on the basis of elemental analysis, i.r., 1H-n.m.r., electronic spectral studies, conductivity and magnetic susceptibility measurements. 相似文献
85.
Rishika Rupam 《Journal d'Analyse Mathématique》2017,131(1):189-206
Inner functions are an important and popular object of study in the field of complex function theory. We look at meromorphic inner functions with a given spectrum and provide sufficient conditions for them to have uniformly bounded derivative on the real line. This question was first studied by Louis de Branges in 1968 and was later revived by Anton Baranov in 2011. 相似文献
86.
87.
Dinda Soumitra Sarkar Koushik Panda Bikash Kumar Pramanik Kausikisankar Ganguly Sanjib 《Transition Metal Chemistry》2022,47(1):31-38
Transition Metal Chemistry - By using a multifunctional diarylazooxime ligand LNOH 1, incorporating electron deficient azo chromophore in conjunction with a pendant π-electron-rich naphthyl... 相似文献
88.
Baruah Bhargav Kataki Rupam Thakur Parash Tiwari Pankaj 《Journal of Thermal Analysis and Calorimetry》2019,138(2):1221-1232
Journal of Thermal Analysis and Calorimetry - The present work provides a detailed characterization and kinetic study of oil shale of Upper Assam, India. The physicochemical characteristics of oil... 相似文献
89.
The role of C-H...pi and C-H...O interactions in HF(2)(-)-assisted self-assembly of nitrogen-containing bisphenols are investigated. Unusual control on the end-face and edge-face geometries of aromatic C-H...pi interactions by a water molecule in the 4-[(4-hydroxy-3,5-dimethylphenyl)methyl]pyridinium difluoride lattice is observed. The bis(4-hydroxy-3,5-dimethylphenyl)(4-ammoniophenyl)methane.HF(2)(-) self-assembles through the formation of hydrogen-bonded cyclic hexamers. 相似文献
90.
An anthrylidene derivative of arjunolic acid could immobilize varieties of organic solvents at low concentrations in the presence of an electron-deficient guest. Gelation in the presence of picric acid in organic solvents could be observed visually with concomitant color change. Electron micrographs of the xerogels showed a fibrous structure having fibers of submicron diameters. [structure: see text]. 相似文献