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101.
102.
B. Deva Prasad Raju K.V. Narasimhulu J. Lakshmana Rao 《Journal of Physics and Chemistry of Solids》2005,66(5):753-761
X-band electron paramagnetic resonance (EPR) studies on divalent copper ions embedded in KMgClSO4·3H2O single crystals have been performed at low temperature (123 K). The angular variation of the EPR spectra reveals the presence of two Cu2+ sites, which have different orientations. The spin-Hamiltonian parameters of this six-coordinated cupric ion have been evaluated from the EPR spectra at 123 K. The forbidden lines due to ΔmI=±1 transitions are observed in between allowed transitions. The temperature variation EPR studies have also been performed both for a single crystal and a polycrystalline sample. The ground state wavefunction of Cu2+ ions has been estimated and is found to be an admixture of d3z2−r2 and dx2−y2. The temperature variation of the EPR spectra reveals that Cu2+ ions exhibit dynamic Jahn-Teller effect. From the polycrystalline EPR data, the temperature dependent magnetic susceptibilities are evaluated and discussed. 相似文献
103.
ZnO-ZnF2-B2O3 glasses containing small concentrations of TiO2 ranging from 0 to 0.6 mol% were prepared. Dielectric properties (constant ε′, loss tan δ, ac conductivity σac over a moderately wide range of frequency and temperature at room temperature in air medium) of these glasses have been studied. The results of these studies were analyzed with the aid of data on optical absorption, ESR and IR spectra of these glasses. The analysis suggests that when the concentration of TiO2>0.2 mol%, the titanium ions, in addition to Ti4+ state, co-exist in Ti3+ state, act as modifiers and reduce the breakdown strength. 相似文献
104.
Raju Suresh Kumar 《Tetrahedron letters》2007,48(40):7164-7168
One-pot, three-component tandem reactions of cyclic mono ketones, isatin and sarcosine affording dispiropyrrolidines stereoselectively are reported for the first time. 相似文献
105.
C.S. Sundar Y. Hariharan A. Bharathi M. Premila V.S. Sastry G.V.N. Rao J. Janaki D.V. Natarajan K.V. Devadhasan T.S. Radhakrishnan N. Subramanian P.Ch. Sahu M. Yousuf S. Raju V.S. Raghunathan M.C. Valsakumar 《Progress in Crystal Growth and Characterization of Materials》1997,34(1-4):11-23
Amongst the other physical properties, the structure of fullerene solids, and the structural transformations with temperature, pressure and doping have all evoked considerable interest and during the last two years tremendous progress has been made in this area. This paper provides a brief review of the studies on the structural properties of pristine and doped fullerenes. The results of our own investigations are also presented. 相似文献
106.
Rao P.V.N. Raju C.S. Rao K.S. 《Geoscience and Remote Sensing, IEEE Transactions on》1990,28(1):148-151
In view of the influence of soil texture on microwave radiation, an attempt is made to eliminate the textural effects on the microwave reflectivity/emission. To determine the appropriate soil moisture parameter that minimizes the textural influences on microwave radiation from soils, soil moisture is expressed in terms of gravimetric and volumetric units and percentage of field capacity (M fc ) and is plotted individually against the microwave reflectivity of soils. Only when soil moisture is in volumetric units are the textural influences significantly reduced. Therefore, a parameter, termed the critical water content (W c), that takes into account the bound-water content of soils is used. An empirical relation between the interpolated values of W c and the wilting point of soils has been developed. The soil water content above the W c of each soil is considered as effective water M eff 相似文献
107.
G. V. L. N. Murty F.A.Sc. K. S. R. Krishnaiah M. S. Raju 《Proceedings Mathematical Sciences》1966,64(2):84-90
Some systematic studies have been carried out on the influence of temperature on the photometric determination of silicon by the molybdenum blue procedure. It has been shown that temperature exerts a distinct influence on the colour intensities involved in the different procedures and the extent of this influence depends largely on the nature of the acid medium and the reducing agent employed. Ascorbic acid has been successfully employed to overcome the influence of temperature. Our thanks are due to the management of the Tata Iron and Steel Company for permitting the publication of this paper. 相似文献
108.
109.
C6H5IO in CH3OH-H20 is activated towards electrophilic attack upon various alkenes by Fe(ClO4).9H2O, FE(III) bleomycin and ZN(II) bleomycin. The results imply that direct transfer of oxygen from an Fe(V)=0 intermediate is not required in the mechanism of oxygenation by iron-containing species, and that much earlier work is questionable as models for biological oxygenation. 相似文献
110.
Calcite single crystals on neutron bombardment change their colour to pale red, red and deep red, as the duration of irradiation
increases. The irradiated surface becomes rugged and on etching, a large number of micropits are observed. Using Vicker’s
hardness indenter, it is observed that the hardress of the irradiated crystal increases with the increase in the total dosage.
From Laue x-ray diffraction studies of irradiated crystals, distortion of lattice is observed. Absorption spectra in the visible
region show an extra peak for irradiated samples which is absent for radiated ones. The radiation effects are annealed to
a considerable extent on heat treatment. The implications are discussed. 相似文献