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721.
The effects of a variety of defect centres such as T03, T02, T01 and their interacting units on the electronic structure of the amorphous silicon has been studied in a cluster Bethe lattice method. The gap states arising from these defects may explain a number of experimental observations. 相似文献
722.
K. G. Varshney S. Agrawal K. Varshney U. Sharma S. Rani 《Journal of Radioanalytical and Nuclear Chemistry》1984,82(2):299-308
Effect of various doses of gamma radiation on the ion-exchange capacity, distribution coefficient values, elution behaviour, pH titration and infrared spectra of some thermally stable inorganic ion exchangers has been studied systematically. No change has been observed in the ion-exchange capacity, elution behaviour and the infrared spectra of the materials irradiated up to a total dose of 3·108 rad, while, a change has been observed in their pH-titration and distribution behaviour. 相似文献
723.
Bachan S. Rawat Dr. Mabesh C. Agrawal 《Monatshefte für Chemie / Chemical Monthly》1976,107(3):757-761
The kinetics of oxidation of semicarbazide by N-monochlorobenzamide was investigated in hydrochloric acid medium. The reaction follows first order dependence in N-chlorobenzamide, semicarbazide and hydrogen ions. Methanol increases the rate while increase in ionic strength has little effect on the reaction rate. A mechanism involving the interaction between protonated N-chlorobenzamide and semicarbazide in the rate determining step is suggested. 相似文献
724.
It has been demonstrated that the Mott-Littleton theory of dielectric constant is consistent with the recent experimental data on the pressure dependence of dielectric constant of alkali halides. On the other hand, the Clausius-Mossotti and Drude models yield large deviations from the observed data. 相似文献
725.
Khadikar PV Karmarkar S Agrawal VK 《Journal of chemical information and computer sciences》2001,41(4):934-949
A novel topological index, PI (Padmakar-Ivan index), is derived in this paper. The index is very simple to calculate and has disseminating power similar to that of the Wiener (W) and the Szeged (Sz) indices. The comprehensive studies show that the proposed PI index correlates highly with W and Sz as well as with physicochemical properties and biological activities of a large number of diversified and complex compounds. The proposed PI index promises to be a useful parameter in the QSPR/QSAR studies. The stability of each model is demonstrated by applying cross-validation test. Furthermore, more favorable comparison with other representative indices such as the Randic index is also made in order to establish the predictive ability of the PI index. The results have shown that in several cases the PI index gave better results. 相似文献
726.
This article presents the results of a detailed theoretical and experimental analysis carried out on a folded Z-shaped polarization
coupled, electro–optically Q-switched laser resonator with Porro prisms and waveplates. The advantages of adding waveplates
in a Porro prism resonator have been explored for creating high loss condition prior to Q-switching and obtaining variable
reflectivity with fixed orientation of Porro prism. Generalized expressions have been derived in terms of azimuth angles and
phase shifts introduced by the polarizing elements. These expressions corroborate with known reported results under appropriate
substitutions. A specific case of a crossed Porro prism diode-pumped Nd:YAG laser has been theoretically and experimentally
investigated. In the feedback arm, a 0.57λ waveplate oriented at 135° completely compensates the phase shift of a fused silica
Porro prism and provides better tolerances than a BK-7 prism/0.60λ waveplate combination to stop prelasing. The fused silica
prism/0.57λ combination with waveplate at 112° acts like a 100% mirror and was utilized for optimization of free running performance.
The effective reflectivity was determined for various orientations of the quarter waveplate in the gain arm to numerically
estimate the Q-switched laser pulse parameters through rate equation analysis. Experimental results match well with the theoretical
analysis.
PACS 42.60.Gd; 42.55.Rz; 42.25.Ja 相似文献
727.
728.
Yufeng Xu Om P. Agrawal 《Communications in Nonlinear Science & Numerical Simulation》2013,18(12):3575-3589
This paper presents three generalizations of the van der Pol equation (VDPE) using newly proposed three new generalized K-, A- and B-operators. These operators allow kernel to be arbitrary. As a result, these operators provide a greater generalization of the VDPE than the fractional integral and differential operators do. Like the original VDPE, the generalized van der Pol equations (GVDPEs) are also nonlinear equations, and in most cases, they can not be solved analytically. Numerical algorithms are presented and used to solve the GVDPEs. Results for several examples are presented to demonstrate the effectiveness of the numerical algorithms, and to examine the behavior of the GVDPEs and the limit cycles associated with them. Although the numerical algorithms have been used to solve the GVDPEs only, they can also be used to solve many other generalized oscillators and generalized differential equations. This will be considered in the future. 相似文献
729.
We show through numerical simulations that silicon waveguides can be used to create a supercontinuum extending over 400 nm by launching femtosecond pulses as higher-order solitons. The physical process behind continuum generation is related to soliton fission, self-phase modulation, and generation of Cherenkov radiation. In contrast with optical fibers, stimulated Raman scattering plays little role. As low-energy (approximately 1 pJ) pulses and short waveguides (<1 cm) are sufficient for continuum generation, the proposed scheme should prove useful for practical applications. 相似文献
730.
We discover analytically an extensive family of optical similaritons, propagating inside graded-index nonlinear waveguide amplifiers. We show that there exists a one-to-one correspondence between these novel similaritons and standard solitons of the homogeneous nonlinear Schr?dinger equation. We demonstrate that for certain inhomogeneity and gain profiles, the newly discovered similaritons turn into solitons over sufficiently long propagation distances. 相似文献