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91.
Y.N.Ch. Ravi Babu P. Sree Ram Naik K. Vijaya Kumar N. Rajesh Kumar A. Suresh Kumar 《Journal of Quantitative Spectroscopy & Radiative Transfer》2012,113(13):1669-1675
The multicomponent lead bismuth magnesium borophosphate glass systems (LBMBPS) doped with Samarium ions with the molar compositions of (50?x)PbOxBi2O325MgHPO424B2O31Sm2O3 (where x=10, 20, 30, and 40) were fabricated using conventional melt quenching technique. The amorphous nature of these glass samples was confirmed with XRD studies. The spectral data from the optical absorption studies were employed to compute various spectroscopic parameters such as Judd–Ofelt intensity parameters. The Judd–Ofelt parameterization employed reflects the covalency and vibration frequencies of the ligands with Samarium ions. The radiative parameters such as radiative transition probabilities (A), the total radiative transitional probabilities (AT), radiative life times (τR), branching ratios (β) and absorption cross sections (Σ) were computed for certain lasing levels. The glass systems thus developed indicate their potential lasing candidature. The emission cross sections (σE) for the significant lasing transitions 4G5/2→6H5/2, 4G5/2→6H7/2, and 4G5/2→6H9/2 evaluated from the photoluminescence spectra were reported. The radiative properties obtained in our investigations suggest their lasing candidature. 相似文献
92.
P. D. Sree Hari Chirodeep Bakli Suman Chakraborty 《Journal of Polymer Science.Polymer Physics》2016,54(20):2118-2125
Trapping macromolecules in nanopits finds diverse applications in polymer separation, filtering biomolecules etc. However, tuning the locomotion of polymers in channels of nanoscopic dimensions is greatly restricted by the comparative advective and diffusive components of velocities. Using the polymer affinity toward the solvent and the wall, and the polymer structure, a mechanism is proposed to induce selective trapping of polymers. Similar to fractional distillation of hydrocarbons based on molecular weight, a technique of fractional segregation, depending on the channel wettability of polymeric chains at different depths in a pit that is located perpendicular to the flow is suggested. Depending on the properties of the polymeric chains and the surface chemistry, the segregation of the polymer at a particular level in the pit can be predicted. This behavior stems from the difference in polymer structure leading to a competition between wettability based enthalpic trapping and structure based entropic trapping. The results of this study suggest a novel way of separating biopolymers based on their structure without relying on the channel geometry. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 2118–2125 相似文献
93.
Dehydration reactions involving the 3-OH of ring-A in acacic acid lactone (1), sapogenin-B (2), methyl exhinocystate (3) and methyl oleanolate (4) have been carried out with different reagents: POCl3/pyridine, PCl5/hexane and solvolysis of their 3-tosylates. Structures of the different products obtained have been assigned based on the study of their PMR and mass spectra. Dependence of the conformational strain of the rest of the molecule other than ring-A is felt considerably on the course of dehydration with milder reagents, e.g. POCl3/pyridine and solvolysis but not with PCl5. 相似文献
94.
Hiroshi Shiigi Hidetaka Yakabe Masayoshi Kishimoto Daisuke Kijima Yuan Zhang Usha Sree Bhavana A. Deore Tsutomu Nagaoka 《Mikrochimica acta》2003,143(2-3):155-162
This article reviews a novel approach to molecular imprinting technology developed by the authors. Preparation, characterization, and performance of the molecularly imprinted overoxidized polypyrrole colloids is discussed to discriminate amino acid enantiomers and structural isomers of naphthalene compounds by using electrochemical and spectroscopic techniques. An overoxidized colloid, which was prepared with L-lactate as a dopant, shows a higher affinity for L-alanine than for D-alanine, and an uptake ratio (L/D) of as high as 11 was observed under optimum conditions. Furthermore, an overoxidized colloid with a cavity created by 1-naphthalenesulfonate (1-NS) showed a higher uptake for 1-NS than 2-NS. Thus, the shape-complementary cavity created at the colloid surface can precisely recognize the difference in the spatial configuration of enantiomers and structural isomers. 相似文献
95.
The area enclosed by hysteresis loops in a periodically forced bistable microscopic system at zero-temperature is examined by using the time dependent Hellmann-Feynman theorem and the Fourier grid Hamiltonian recipe for solving time-dependent Schrödinger equation. Effects of non-zero temperatures are explored with reference to a symmetric double well potential. The barrier crossing or, relaxation rates are shown to correlate systematically with the area of the loop. The possible use of hysteresis loop area in designing field parameters for optimal control is suggested. 相似文献
96.
S.?Sree?Ranjani A.?K.?Kapoor P.?K.?PanigrahiEmail author 《International Journal of Theoretical Physics》2005,44(8):1167-1176
Various quasi-exact solvability conditions, involving the parameters of the periodic associated Lamé potential, are shown
to emerge naturally in the quantum Hamilton–Jacobi (QHJ) approach. We study the singularity structure of the quantum momentum
function, which yields the band-edge eigenvalues and eigenfunctions and compare it with the solvable and quasi-exactly solvable
non-periodic potentials, as well as the periodic ones. 相似文献
97.
98.
The effect of dopant cesium (Cs(I)) over a concentration range from 1 to 10 mol% on the growth process, morphology, thermal and optical properties of tri(thiourea)zinc(II) sulfate (ZTS) single crystals grown by slow evaporation solution growth technique has been investigated. Incorporation of Cs(I) into the crystal lattice was well confirmed by energy dispersive X-ray spectroscopy (EDS). The lattice parameters of the as-grown crystals were obtained by single crystal X-ray diffraction analysis. The reduction in the intensities observed in powder X-ray diffraction patterns of doped specimen and slight shifts in vibrational frequencies in fourier transform infrared spectra (FT-IR) indicate the lattice stress as a result of doping. Thermal studies reveal the purity of the material and no decomposition is observed up to the melting point. High transmittance is observed in the visible region and the cut-off λ is ~280 nm. The surface morphology of the as-grown specimens was studied by scanning electron microscopy (SEM). The second harmonic generation (SHG) efficiency of the host crystal is enhanced greatly in the presence of high concentrations of the dopant. 相似文献
99.
Tuning a ring laser by using the Gouy phase is explored. We find a sensitive capability by moving a lens in the ring cavity. Application of the effect to ring laser gyro is discussed. 相似文献
100.
A solvent-free mechanochemical route for the preparation of poly(2,5-dimethoxyaniline) hydrochloride nanostructures is developed
and reported in the article. High conductivity, good crystallinity, and nanostructured morphology are observed for the prepared
polymer. This polymeric powder is utilized as a cathode material in hybrid supercapacitor and its electrochemical performance
is evaluated and discussed in this short report. The maximum specific capacitance of the poly(2,5-dimethoxyaniline) hydrochloride/activated
carbon hybrid supercapacitor is found to be 125 F g−1 at 1 mA cm−2 current density. The cell delivers a specific energy as high as 50 Wh kg−1 at a specific power of 97 W kg−1 and also exhibits an excellent cycle performance with more than 99% coulombic efficiency and the maintenance of 85% of its
initial capacitance after 1,000 cycles. 相似文献