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51.
Loganathan Ramu Narendra Kuppan Keralapura Parthasarathy Ramesh Rattihalli Chandramani Daivagna Ramananda 《Magnetic resonance in chemistry : MRC》2019,57(8):499-505
35Cl NQR frequency and spin lattice relaxation time in 3,4-dichloronitrobenzene have been measured as a function of temperature and pressure. Two NQR signals were observed in the temperature range 77 to 300 K and pressure up to 5.1 kbar at 300 K. The contributions to the relaxation from the torsional motion of the molecule and reorientational motion of the nitro group have been analyzed on the basis of the Woessner and Gutowsky model. The temperature dependence of the average torsional lifetimes of the molecules, transition probabilities, and the activation energy for the reorientation of the nitro group was estimated. The pressure dependence of the NQR frequency in 3,4-Dichloronitrobenzene shows a nonlinear increase in NQR frequency with increase in pressure, indicating increased contribution from the static effects at higher pressures. A thermodynamic analysis of the data was carried out to determine the constant-volume temperature coefficients of the NQR frequency. The spin–lattice relaxation was found to be weakly dependent on pressure. 相似文献
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53.
Anuj Jakhar Sudesh K. Khanduja Neeraj Sangwan 《Journal of Pure and Applied Algebra》2018,222(4):889-899
Let v be a Krull valuation of a field with valuation ring . Let θ be a root of an irreducible trinomial belonging to . In this paper, we give necessary and sufficient conditions involving only for to be integrally closed. In the particular case when v is the p-adic valuation of the field of rational numbers, and , then it is shown that these conditions lead to the characterization of primes which divide the index of the subgroup in , where is the ring of algebraic integers of K. As an application, it is deduced that for any algebraic number field K and any quadratic field L not contained in K, we have if and only if the discriminants of K and L are coprime. 相似文献
54.
Anuj Jakhar Sudesh K. Khanduja Neeraj Sangwan 《Journal of Pure and Applied Algebra》2018,222(11):3560-3565
It is well known that if are algebraic number fields with coprime discriminants, then the composite ring is integrally closed and are linearly disjoint over the field of rationals, being the ring of algebraic integers of . In an attempt to prove the converse of the above result, in this paper we prove that if are finite separable extensions of a valued field of arbitrary rank which are linearly disjoint over and if the integral closure of the valuation ring of v in is a free -module for with integrally closed, then the discriminant of either or of is the unit ideal. We quickly deduce from this result that for algebraic number fields linearly disjoint over for which is integrally closed, the relative discriminants of and must be coprime. 相似文献
55.
Narendra Prasad Brian K. Nicholson C. John McAdam 《Journal of organometallic chemistry》2010,695(17):1961-5456
2-Ferrocenyl-substituted pyrylium salts are produced when orthomanganated chalcones are reacted with ethynylferrocene in CCl4. When the reaction is carried out in benzene, intermediate ferrocenyl-substituted (η5-pyranyl)Mn(CO)3 species can be isolated which give the pyrylium cations on oxidation. The electrochemistry of the 2-ferrocenyl-pyrylium cations shows both oxidation (of the ferrocenyl) and reduction (of the pyrylium) processes, and the UV-visible spectra show a broad band at ca 680 nm which can be assigned to an intramolecular charge transfer transition. 相似文献
56.
Suzuki–Miyaura cross-coupling reactions of aryl halides with arylboronic acids were performed in predominantly aqueous media employing two mono- and two dinuclear cyclopalladated complexes as catalysts. These complexes are [Pd(HL)Cl] (I), [Pd(L)(PPh3)] (II), [Pd2(μ-dppb)(L)2] (III) and [Pd2(μ-dppf)(L)2] (IV); where H2L, dppb and dppf represent 4-methoxy-N′-(mesitylidene)benzohydrazide, 1,4-bis(diphenylphosphino)butane and 1,1′-bis(diphenylphosphino)ferrocene, respectively. The reactions were conducted using potassium carbonate as base in presence of tetrabutylammonium bromide (TBAB) at 70/90 °C in dimethylformamide–water (1:20) mixture. Among the four catalysts used, the dinuclear complex IV turned out to be the most effective and afforded moderate to excellent yields with broad substrate scope. 相似文献
57.
Faysal Benaskar Volker Engels Narendra Patil Jan Meuldijk Lumbertus A. Hulshof Jaap. C. Schouten Andrew E.H. Wheatley 《Tetrahedron letters》2010,51(2):248-5988
The action of nanoparticulate copper catalysts with a mean particle size of 10 nm in the Ullmann ether synthesis is reported using multimode microwave heating and employing stable chloropyridine salts and unactivated phenol, with stabilized copper nanoparticles outperforming other copper catalysts in terms of stability and reusability. 相似文献
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59.
A two-dimensional tilted axis cranking Hartree-Fock-Bogoliubov (CHFB) calculation is performed for 76Kr and 78Kr nuclei up to high spins J = 30 employing a pairing-plus-quadrupole (PPQ) model interaction Hamiltonian. Intricate details of the evolution of single
particle structures and shapes as a function of spin have been investigated. The results show the existence of energy levels
with high K quantum numbers lying close to the yrast line in both the nuclei. Such high K states should exhibit isomeric characteristics due to the K-selection rules for the γ-decays. Moreover, in 78Kr a new band with J = 20–30 lying below the observed ground band is predicted.
相似文献
60.
Photolysis studies on MAg4I5 films are reported. The electrical conductivities of MAg4I5 films have been found to change when exposed to mercury light. This is explained on the basis of a model similar to Mott-Gurney theory of photolysis for silver halides. The formation of silver specks has been confirmed by photomicrographic studies. 相似文献