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981.
Microwave-mediated three-component condensation of 4-aryl-4-oxobutanoates with ammonium formate furnishes 3-methylidene-5-phenyl-2,3-dihydropyrrolidones
in good yield within 2 min. The pyrrolidone products were characterized on the basis of spectral data and X-ray crystal structure
analysis. The reaction is found to be general and a variation in the ester and aryl moieties is possible. However, when alkylammonium
formate is used only amide products are formed 相似文献
982.
G. A. Olah A. V. Orlinkov A. B. Oxyzoglou G. K. S. Prakash 《Russian Chemical Bulletin》1998,47(5):924-927
Superelectrophilic nitration of deactivated aromatics with NO2Cl−3MX
n
complexes in aprotic nonpolar solvents such as CH2Cl2 makes it possible to obtain the corresponding nitro derivatives in good to almost quantitative yields under mild conditions.
For part 34, see Ref. 1.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 953–956, May, 1998. 相似文献
983.
The level structure of178Hf is interpreted on the basis of the population of the states following178Hf (d, d′),177Hf (d, p) and179Hf (d, t) reactions. Evidence for quadrupole and octupole vibrational bands and unmixed and intermixed two-quasiparticle configurations
is presented. 相似文献
984.
T. Datta S. P. Dange S. M. Sahakundu S. Prakash M. V. Ramaniah 《Zeitschrift für Physik A Hadrons and Nuclei》1988,330(1):103-109
In the present work rms angular momenta have been deduced for the fission fragments corresponding to131Tem,g and133Tem,g in232Th(α 40 MeV,f) and238U(α 40 MeV,f) systems from the radiochemically determined independent isomeric yield ratios and statistical model based analysis. For131Te and133Te the rms angular momenta deduced are 5.9±1.0 and 7.9±1.2 ? respectively in232Th(α 40 MeV,f) and 7.2±0.6 and 8.0±0.8 ? respectively in238U(α 40 MeV,f). Comparison of the present data with the literature data for these fragments in the same compound nuclei236U* and242Pu* at lower excitation energies shows increase in the fragment angular momentum with increasing excitation energy and angular momenta of the fissioning nuclei. Fragment angular momentum deduced theoretically for asymmetric and deformed fragments on the basis of thermal equilibration of the collective rotational degrees e.g., rigid rotation, wriggling, tilting, bending and twisting modes considering the effect of multichance fission, are in good agreement with the experimental observations. 相似文献
985.
The strain field due to body centered substitutional transition metal impurities in Ni and Pd metals are investigated. The
calculations are carried out in the discrete lattice model of the metal using Kanzaki lattice static method. The effective
ion-ion interaction potential due to Wills and Harrison is used to evaluate dynamical matrix and the impurity-induced forces.
The results for atomic displacements due to 3d, 4d and 5d impurities (Fe, Co, Cu, Nb, Mo, Pd, Pt and Au) in Ni and (Fe, Co,
Cu, Ni, Nb, Mo, Pt and Au) impurities in Pd are given up to 25 NN’s of impurity and these are compared with the available
experimental data. The maximum displacements of 4.6% and 3.8% of 1NN distance are found for NiNb and PdNb alloys respectively,
while the minimum displacements of 0.63% and 0.23% of 1NN distance are found for NiFe and PdFe alloys respectively. Except
for Cu, the atomic displacements are found to be proportional to the core radii and d state radius. The relaxation energies
for 3d impurities are found less than those for 4d and 5d impurities in Ni and Pd metals. Therefore, 3d impurities may easily
be solvable in these metals. 相似文献
986.
Some modifications have been suggested to the nodal slide and microscope method to suit the focal length measurement of large focal length lenses. In this procedure, the experimental set-up has to be accommodated on the two usual optical benches in line, and the position of the nodal point of the lens under test is easily located by introducing an extra lens of comparatively shorter focal length between the test lens and microscope. The results of the measurement of ‘f’ for a few lenses, and the experimental parameters, are presented. 相似文献
987.
The effect of finite Larmor radius, magnetic field, rotation and variable gravitational field on thermal instability of fluid
layer in porous medium is investigated. It is found that the principle of exchange of stability is valid in the absence of
magnetic field and rotation. The system is stable/unstable depending upon certain conditions in the presence of rotation,
magnetic field and medium permeability. The system is stable in presence of finite Larmor radius.
The above work has been carried out under research project financed by University Grants Commission New Delhi (India) and
the authors are grateful to University Grants Commission for their financial support. 相似文献
988.
Sanju KS Neelakandan PP Ramaiah D 《Chemical communications (Cambridge, England)》2011,47(4):1288-1290
We observed FRET between an excimer of a partially intercalated cyclophane and ethidium bromide, a classical intercalator in presence of DNA and by fine-tuning the molar concentrations of these three components, we could generate white light emission in the aqueous and non-aqueous media. 相似文献
989.
990.