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51.
The reaction of phenols with 7a led to the synthesis of aurones, while the reaction of phenols with 7b led to the synthesis of flavones. 相似文献
52.
Sharief Deshmukh 《Monatshefte für Mathematik》2014,174(3):413-426
We study the influence of a unit Killing vector field on the geometry of a hypersurface in the unit sphere. The combination of the Killing vector field on the hypersurface and the conformal vector field on the ambient sphere triggers the presence of four specific smooth functions on the hypersurface, we use these four functions to derive different sufficient conditions for a hypersurface to be the totally geodesic sphere and for a minimal hypersurface to be the totally geodesic sphere, Clifford minimal hypersurface respectively. In particular we classify compact minimal hypersurfaces with a unit Killing vector field in the unit sphere. 相似文献
53.
For a Lagrangian submanifold M of S 6 with nearly Kaehler structure, we provide conditions for a canonically induced almost contact metric structure on M by a unit vector field, to be Sasakian. Assuming M contact metric, we show that it is Sasakian if and only if the second fundamental form annihilates the Reeb vector field ξ, furthermore, if the Sasakian submanifold M is parallel along ξ, then it is the totally geodesic 3-sphere. We conclude with a condition that reduces the normal canonical almost contact metric structure on M to Sasakian or cosymplectic structure. 相似文献
54.
P. M. Kadam N. L. Tarwal P. S. Shinde R. S. Patil H. P. Deshmukh P. S. Patil 《Applied Physics A: Materials Science & Processing》2009,97(2):323-330
Suitable host lattice and morphology for easy intercalation and deintercalation process are crucial requirements for electrochromic
device. In this investigation, the evolution of structural and morphological changes and their effect on electrochromic (EC)
properties of spray-deposited WO3 thin films are studied. Films of different morphologies were deposited from an ammonium tungstate precursor solution using
a novel pulsed spray pyrolysis technique (PSPT) on tin-doped indium oxide (ITO) coated glass substrates by varying quantity
of spraying solution. Interesting morphological transition from beads-to-wires-to-fibers as a function of quantity of sprayed
solution has been demonstrated. The porosity, crystallinity and “open” structures in the films consisting of beads, wires,
and fiber-like morphology enabled us to correlate these aspects to their EC performance. WO3 films comprising wire-like morphology (20 cc spraying quantity) exhibited better EC properties both in terms of coloration
efficiency (42.7 cm2/C) and electrochemical stability (103 colored/bleached cycles) owing to their adequate open structure, porosity, and amorphicity, compared with the films having
bead/fiber-like morphology. 相似文献
55.
Chintamani Mande Subha Chattopadhyay Prabodh C Deshmukh R Padma Pranawa C Deshmukh 《Pramana》1990,35(4):397-403
A new scale of electronegativity based on X-ray spectroscopic data was earlier presented by Mande and others for the elements3Li to54Xe. The present paper reports an extension of this scale carried out for most of the heavier elements lying between55Cs and92U. The present approach is based on the physical interpretation of electronegativity of an atom as the attractive electrostatic
force it exerts at a distance equal to its covalent radius. To estimate this force, experimental spectroscopic data have been
employed. The merits of such an approach have been pointed out recently by Mullay and may be of interest in the context of
the intimate relation found between electronegativity and superconducting transition temperature. 相似文献
56.
Dipole-allowed single photoionization of some closed shell atoms and ions has been investigated in the relativistic random-phase
approximation (RRPA). Application of relativisticmultichannel quantum defect theory (RMQDT) is made together with RRPA to
analyse autoionizing resonances. Analysis points to the importance of interchannel coupling in high energy photoionization
and reveals various degeneracies in relativistic atomic spectra to influence the low energy dynamics. Interesting threshold
behavior in photoelectron spin polarization has been seen. Prospective future studies have been indicated. 相似文献
57.
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
58.
Das MR Sarma RK Saikia R Kale VS Shelke MV Sengupta P 《Colloids and surfaces. B, Biointerfaces》2011,83(1):16-22
A solution-based approach to the synthesis of silver (Ag) nanoparticles by chemical reduction of AgNO(3) in a graphene oxide (GrO) suspension is demonstrated. X-ray diffraction and transmission electron microscopy indicate that the Ag nanoparticles, of size range 5-25nm, were decorated on the GrO sheets. The size and shape of the Ag nanoparticles are dependent on the concentration of the AgNO(3) solution. Antimicrobial activity of such hybrids materials is investigated against the Gram negative bacteria Escherichia coli and Pseudomonous aeruginosa. The bacterial growth kinetics was monitored in nutrient broth supplemented with the Ag nanoparticle-GrO suspension at different conditions. It was observed that P. aeruginosa is comparatively more sensitive to the Ag nanoparticle-GrO suspension. 相似文献
59.
Production of the fibrinolytic enzyme was carried out using 2.5-L glass fermentor, culture of thermophilic Streptomyces sp., and glucose yeast extract peptone medium of pH 8.0. Five successive batches were carried out under controlled fermentation conditions viz., agitation 140 rpm, aeration 0.5 vvm, 55 °C, and 18 h. The total protein extracellularly produced in the cell-free broth was ~300-500 mg/L. The enzyme belongs to serine endopeptidase type. Studies on the fibrin degradation indicate that the enzyme degrades the fibrin into small molecular weight products as seen from HPLC profile. Phase-contrast microscopic structure of fibrin showed that enzyme cleaves the fibrin filaments. The ex vivo activity of the actinokinase was compared with 500 IU of urokinase and 350 IU of streptokinase. The ex vivo clot lysis was found to be faster as compared to the commercial available enzymes. 相似文献
60.
Androulakis J Todorov I He J Chung DY Dravid V Kanatzidis M 《Journal of the American Chemical Society》2011,133(28):10920-10927
We report promising thermoelectric properties of the rock salt PbSe-PbS system which consists of chemical elements with high natural abundance. Doping with PbCl(2), excess Pb, and Bi gives n-type behavior without significantly perturbing the cation sublattice. Thus, despite the great extent of dissolution of PbS in PbSe, the transport properties in this system, such as carrier mobilities and power factors, are remarkably similar to those of pristine n-type PbSe in fractions as high as 16%. The unexpected finding is the presence of precipitates ~2-5 nm in size, revealed by transmission electron microscopy, that increase in density with increasing PbS concentration, in contrast to previous reports of the occurrence of a complete solid solution in this system. We report a marked impact of the observed nanostructuring on the lattice thermal conductivity, as highlighted by contrasting the experimental values (~1.3 W/mK) to those predicted by Klemens-Drabble theory at room temperature (~1.6 W/mK). Our thermal conductivity results show that, unlike in PbTe, optical phonon excitations in PbSe-PbS systems contribute to heat transport at all temperatures. We show that figures of merit reaching as high as ~1.2-1.3 at 900 K can be obtained, suggesting that large-scale applications with good conversion efficiencies are possible from systems based on abundant, inexpensive chemical elements. 相似文献