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151.
Sushil K. Misra Serguei I. Andronenko Prem Chand Keith A. Earle Sergei V. Paschenko Jack H. Freed 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2005,174(2):2308-269
EPR measurements have been carried out on a single crystal of Mn(2+)-doped NH(4)Cl(0.9)I(0.1) at 170-GHz in the temperature range of 312-4.2K. The spectra have been analyzed (i) to estimate the spin-Hamiltonian parameters; (ii) to study the temperature variation of the zero-field splitting (ZFS) parameter; (iii) to confirm the negative absolute sign of the ZFS parameter unequivocally from the temperature-dependent relative intensities of hyperfine sextets at temperatures below 10K; and (iv) to detect the occurrence of a structural phase transition at 4.35K from the change in the structure of the EPR lines with temperature below 10K. 相似文献
152.
Prabudh R. Misra 《Semigroup Forum》1996,52(1):105-108
In this note we verify a conjecture of Magill [3] about orders of “steplike” functions. These functions turn out to be useful
in producing a finite subsemigroup of S(ℝ) of any given order. 相似文献
153.
A relation between the free energy for dipole relaxation process and that for the association process has been proposed. Using this relation, an equation has been defined for evaluating the association equilibrium constant from the dielectric relaxation measurements. These equations have been applied to study the association of dimethyl sulphoxide and p-tolyl sulphoxide with proton donors (phenol and O-cresol) in an inert solvent carbon-tetra-chloride in the temperature range 298–322K. The calculation of the association equilibrium constant and hence the thermodynamic parameters have shown the wide scope, the proposed relations can be put to in the study of the association process of hydrogen bond complexes. 相似文献
154.
The cell model for diffusion transition has been applied to study first order phase transition and its pressure dependence in polyethylene. The experimental data of Matsuoka have been utilized. The agreement with experimental curves gets progressively better at higher pressure values because of the accompanied crystallisation. 相似文献
155.
156.
X-band data on Gd3+ ions doping some isostructural single crystals of rare-earth trisulphate octahydrate [R2(SO4)3·8H2O] single crystals (RSH) have been obtained at room temperature for the hosts characterized by R = Pr, Nd, Sm, Eu, Yb and Y, and at liquid nitrogen and liquid helium temperatures for the hosts characterized by R = Pr, Sm, Eu and Y. The data are analyzed using a rigorous least-squares fitting procedure in which all resonant line positions obtained for various orientations of the external magnetic field are fitted simultaneously to the same spin Hamiltonian parameters. The intensities of the lines obtained at liquid helium temperatures indicate the absolute sign of the parameter b20 to be negative for R = Pr, Eu and Y, whereas for the Sm host the sign of b20 is found to be positive. While the parameter b20 does not exhibit a clear cut linear dependence upon the host ion radius, the parameter b20 is found to behave approximately linearly as a function of the host-ion radius. On the other hand, the zero-field splitting is found to be a linear function of the host ion radius at all three temperatures—room, liquid nitrogen and liquid helium.A comparison is presented of the systematics of the EPR spectra for the RSH hosts with those for some other isostructural rare-earth hosts. 相似文献
157.
Ashok Misra 《Applied Physics A: Materials Science & Processing》1978,16(2):195-199
Observations of the fracture-induced electromagnetic effect in metals have recently been reported by the author. This paper
presents a physical model for explaining this new effect. The reasoning attributes the observed electromagnetic effect to
dislocationelectron interactions in a metal. The frequency of the emitted radiation has been calculated from Bohr's correspondence
principle and potential on the basis of Hertzian dipole radiation. The proposed physical model predicts emission of electromagnetic
waves at distinct transition stages of elastic-plastic deformations. The paper also presents some of the experimental results,
being obtained by the author, which confirm the practicability of this approach. 相似文献
158.
Madhusudanan KP Kumar B Tiwari P Madhusudan SK Misra AK 《Journal of mass spectrometry : JMS》2005,40(1):25-35
The effect of metal cationization on the tandem mass spectra of glycosyl dithioacetals of glucose, mannose, galactose, rhamnose, arabinose and xylose was studied by electrospray ionization mass spectrometry under ammonium and metal (Li, Na, Ag and Cu) ion cationization conditions. The ammonium-cationized glycosyl dithioacetals fragment by loss of ammonia followed by either two molecules of EtSH or one molecule of EtSH and one molecule of H2O. Lithium cationization leads to additional eliminations such as EtSEt and EtSSEt and C-C cleavages. Elimination of EtSH is not observed under sodium cationization. Silver cationization, on the other hand, leads to additional fragmentations involving the elimination of silver as AgOH and AgSEt. Copper cationization results in adducts where copper has undergone a change of oxidation state from II to I. Li+, Ag+ and Cu+ cationization seem to favour cyclization resulting in elimination of EtSH. However, the mechanisms seem to be differently affected by different metal ions. Li+ and Ag+ cationization appear to be non-specific and favour cyclization involving C2-, C4- and C5-hydroxyl hydrogens, whereas Cu+ cationization seems to favour cyclization involving C4-hydroxyl hydrogen. 相似文献
159.
EPR spectra of Gd3+-doped Ce2(SO4)3.8H2O and La2(SO4)3.9H2O single crystals have been measured with an X-band spectrometer at room and low temperatures. The absolute signs of spin Hamiltonian parameters have been determined for the La2(SO4)3.9H2O host from intensities of lines at liquid helium temperature; for the Ce2(SO4).8H2O host the lines broaden considerably below 60 K, not permitting the determination of absolute signs of spin Hamiltonian parameters. The data are analysed using a rigourous least-squares procedure, fitting simultaneously all lines obtained for several orientations of the external magnetic field. The zero-field splittings have been computed for both the hosts. The characteristics of EPR spectra of Gd3+ in these hosts are compared with those obtained in other rare-earth trisulphate octahydrate hosts. 相似文献
160.
Misra S. G. und D. P. Sharma 《Colloid and polymer science》1962,184(1):80
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