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91.
Mixtures containing ammonia-borane and sec-butylamine-borane remain liquid throughout the hydrogen release process that affords tri(N-sec-butyl)borazine and polyborazylene. Concentrated solutions with metal catalysts afford >5 wt% H(2) in 1 h at 80 °C and addition of (EMIM)EtSO(4) ionic liquid co-solvent eliminates competing formation of insoluble linear poly(aminoborane) (EMIM = 1-ethyl-3-methyl-imidazolium). 相似文献
92.
Dette Holger Dhar Subhra Sankar Wu Weichi 《Annals of the Institute of Statistical Mathematics》2021,73(5):855-889
Annals of the Institute of Statistical Mathematics - This article studies the problem whether two convex (concave) regression functions modelling the relation between a response and covariate in... 相似文献
93.
B. L. Rao P. P. Parekh M. Sankar Das 《Journal of Radioanalytical and Nuclear Chemistry》1969,2(1-2):79-89
A radiochemical method has been devised for the separation of bismuth activities of the natural series,viz.214Bi,210Bi and212Bi, and applied to the indirect estimation of their corresponding precursors,222Rn,210Pb and212Pb, in a wide variety of geological materials. The method consists of the solvent extraction of bismuth in radiochemically
pure form from the sample solution atpH 2 with diallyldithiocarbamido-hydrazine (Dalzin) in chloroform, and back extraction with 2M acid. The advantages of this method over the dithizone extraction system are discussed. 相似文献
94.
Sharvari Deshmukh Kalyani Kamde Arun Jana Sanjivani Korde Rajib Bandyopadhyay Ravi Sankar Nabarun Bhattacharyya R.A. Pandey 《Analytica chimica acta》2014
Electronic nose systems when deployed in network mesh can effectively provide a low budget and onsite solution for the industrial obnoxious gaseous measurement. For accurate and identical prediction capability by all the electronic nose systems, a reliable calibration transfer model needs to be implemented in order to overcome the inherent sensor array variability. In this work, robust regression (RR) is used for calibration transfer between two electronic nose systems using a Box–Behnken (BB) design. Out of the two electronic nose systems, one was trained using industrial gas samples by four artificial neural network models, for the measurement of obnoxious odours emitted from pulp and paper industries. The emissions constitute mainly of hydrogen sulphide (H2S), methyl mercaptan (MM), dimethyl sulphide (DMS) and dimethyl disulphide (DMDS) in different proportions. A Box–Behnken design consisting of 27 experiment sets based on synthetic gas combinations of H2S, MM, DMS and DMDS, were conducted for calibration transfer between two identical electronic nose systems. Identical sensors on both the systems were mapped and the prediction models developed using ANN were then transferred to the second system using BB–RR methodology. The results showed successful transmission of prediction models developed for one system to other system, with the mean absolute error between the actual and predicted concentration of analytes in mg L−1 after calibration transfer (on second system) being 0.076, 0.1801, 0.0329, 0.427 for DMS, DMDS, MM, H2S respectively. 相似文献
95.
Subramanian V. Sankar Derek Y. Kamemoto William D. Bachalo 《Particle & Particle Systems Characterization》1993,10(6):321-331
A combined theoretical and experimental study has been conducted to evaluate the effectiveness of using large, hollow micro-balloons as LDV seed particles. The study has focused on the ability of phase Doppler systems to size hollow microballoons, the ability of large micro-balloons to respond to high frequency spatial and temporal flow field variations, and the overall advantages and disadvantages of using large microballoons instead of conventional LDV seed particles, such as very small water droplets or polystyrene latex (PSL) particles. This paper discusses the development of a theoretical phase Doppler response model for stratified spheres, the experimental facility, and the theoretical and experimental results. 相似文献
96.
97.
We present a complete theoretical analysis of the periodic and non-periodic travelling waves in a diatomic chain model, in
the continuum limit by incorporating nonlinear sixth order polarization potential (φ6) at the anion site. We have formulated a nonlinear lattice dynamical theory in which various energy curves are obtained for
different types and magnitudes of the core-shell force constants. For periodic solutions, we have obtained two types of commensurate
wave amplitudes which propagate in the opposite direction with respect to each other. For nonperiodic solutions, we have obtained
various travelling excitations such as kink, antikink, excitons etc. for different values of the mass ratio and velocity parameter.
The dipole moment per unit charge for SrTiO3 has been calculated and it is found that the nonlinear excitations in this model carry large amount of energy as compared
to those obtained from harmonic and anharmonic optical phonons in the φ4-polarizable model. 相似文献
98.
The phonon spectra of unstrained and strained quasiperiodic semiconductor superlattices (QSSL) have been calculated using
one-dimensional linear chain model. We consider two types of quasiperiodic systems, namely cantor triadic bar (CTB) and Fibonacci
sequences (FS), constituting of AlAs, GaAs and GaSb of which the latter two have a lattice mismatch of about 7%. The calculations
have been made using transfer matrix method and also with and without the inclusion of strain. We present the results on phonon
spectra of two component CTB and two as well as three component FS semiconductor superlattices (SSL), thickness and order
dependence on LO mode of GaAs, effect of strain on LO frequency of GaAs. The calculated results show that the strain generated
due to lattice mismatch reduces significantly the magnitudes of the confined optical phonon frequency of GaAs. 相似文献
99.
We have investigated the lattice vibrational properties of a two-component strained layer semiconductor superlattice (GaAs)
n1 (GaSb)
n2 using a one-dimensional linear chain model and transfer matrix method [1]. Effect of strain, arising due to the lattice mismatch
(∼ 7%) has been considered explicitly in the equation of motion. We show for the first time that the optical vibrational frequency
increases (in the case of (GaAs)4 (GaSb)
n
) or decreases (in the case of (GaAs)
n
(GaSb)4) with increase of layer thicknessn, in either type of superlattices. Raman scattering measurements on some other similar systems support our findings. 相似文献
100.