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121.
Singh Susheel Kumar Srivastava Akash Dwivedi L. K. Singh Sunil. P. 《Optical Review》2023,30(4):478-484
Optical Review - Water is one of the fundamental needs for human life on earth. Different kinds of contaminants that exist in the drinking water may cause serious health issues, affect body organs,... 相似文献
122.
It is shown that strong curvature naked singularities form in a non-self-similar gravitational collapse of radiation. The imploding radiation space-times with a general form of mass function are analyzed and we show that a strong curvature property holds along all families of non-spacelike geodesies terminating at the singularity in past. In view of the strength of singularity and the non-self-similar nature of space-time, we believe this is a very serious counter-example which must be taken into account for any possible formulation of the cosmic censorship hypothesis.This essay received the fourth award from the Gravity Research Foundation, 1991 — Ed. 相似文献
123.
124.
125.
C. N. R. Rao P. C. Dwivedi Abha Gupta H. S. Randhawa 《Journal of Molecular Structure》1976,30(2):271-290
Properties of hydrogen bonds formed by 1:1 interaction of H2O with oxygen, nitrogen, sulphur and other electron donors have been evaluated by extended Hückel and CNDO methods and the results are discussed in relation to the experimental data. A detailed analysis of the variation of the dissociation energies and charge densities with bond distances is presented for the amine-water system. 1:2 complexes of water with donors are found to contain weaker hydrogen bonds than 1:1 complexes. Results of molecular orbital calculations on the hydrogen bonding of H2S and CH3SH with some donors are presented. The theoretical value of hydrogen bond dissociation energy varies linearly with the overlap population, and stretching force constant of the hydrogen bond as well as with the experimental O—H frequency shift. 相似文献
126.
C P D Dwivedi 《Pramana》1985,25(5):547-555
The semiempirical molecular orbital method known as symmetrically orthogonalised intermediate neglect of differential overlap
(sindo) has been employed to determine the geometry, bonding, binding energy, ionisation potential, dipole moment and net charges
of diketene and cyclobutane-1,3-dione molecules. Results obtained have been compared with available experimental data. 相似文献
127.
Dwivedi H. Frey L. Langhoff H. 《Applied Physics A: Materials Science & Processing》1986,39(3):155-158
Using a 50 ns pulse of an intense proton beam 1.5 J cm–2 of energy was deposited in a 1 m thick surface layer of glass forming alloys. In Fe80B20, the formation of a glassy surface layer of 1.9 m thickness was observed by x-ray diffraction. Etching experiments performed with alloys containing phosphorus yielded similar results. Applying a mask technique amorphous and crystalline zones were structured with a resolution of better than 2 m.On leave from Central Electronics Engineering Research Institute, Pilani, Rajasthan, India 相似文献
128.
Gaurav Dwivedi Jagmohan Tyagi 《NoDEA : Nonlinear Differential Equations and Applications》2016,23(2):10
In this paper, we establish a nonlinear analogue of Picone’s identity for biharmonic operators on Heisenberg group. As an applications of Picone’s identity, we obtain Hardy-Rellich type inequality, Morse index, Caccioppoli inequality, Picone inequality for biharmonic operators on Heisenberg group. 相似文献
129.
Matthew C. Bernier Rosana M. Alberici Joel D. Keelor Prabha Dwivedi Stephen C. Zambrzycki William T. Wallace Daniel B. Gazda Thomas F. Limero Josh M. Symonds Thomas M. Orlando Ariel Macatangay Facundo M. Fernández 《Journal of the American Society for Mass Spectrometry》2016,27(7):1203-1210
Low molecular weight polar organics are commonly observed in spacecraft environments. Increasing concentrations of one or more of these contaminants can negatively impact Environmental Control and Life Support (ECLS) systems and/or the health of crew members, posing potential risks to the success of manned space missions. Ambient plasma ionization mass spectrometry (MS) is finding effective use as part of the analytical methodologies being tested for next-generation space module environmental analysis. However, ambient ionization methods employing atmospheric plasmas typically require relatively high operation voltages and power, thus limiting their applicability in combination with fieldable mass spectrometers. In this work, we investigate the use of a low power microplasma device in the microhollow cathode discharge (MHCD) configuration for the analysis of polar organics encountered in space missions. A metal-insulator-metal (MIM) structure with molybdenum foil disc electrodes and a mica insulator was used to form a 300 μm diameter plasma discharge cavity. We demonstrate the application of these MIM microplasmas as part of a versatile miniature ion source for the analysis of typical volatile contaminants found in the International Space Station (ISS) environment, highlighting their advantages as low cost and simple analytical devices. 相似文献
130.
Prakash C. Srivastava Sangeeta Bajpai Roli Lath Rajesh Kumar Vikas Singh Shrinkhala Dwivedi Ray J. Butcher Satoko Hayashi Waro Nakanishi 《Polyhedron》2008
The reaction of organo(heterocyclic)tellurium(IV) derivative: C8H8TeI2(1,3-dihydro-2λ4-benzotellurole-2,2-diyl diiodide) with NH4S2CNC5H10 (ammonium piperidine dithiocarbamate) gives C8H8Te(S2CNC5H10)2 (1) and Te(S2CNC5H10)2 (2) or C8H8TeI(S2CNC5H10) (5) according to the reaction conditions. In such type of metathetical reactions, the formation of 2 is unprecedented and it corresponds to the first Te–C cleaved product. The reaction of 2 with CH3I, yields the oxidative addition product, CH3TeI(S2CNC5H10)2 (8). The formation of 2 is also supported through Quantum Chemical calculations. Another Te–C bond cleaved product TeI2[(C13H10N2S)2] · 4C4H8TeI2 (9) is obtained in the reaction of C4H8TeI2 (1,1,2,3,4,5-hexahydro-1,1-diiodotellurophene) with NH4S2CNHC6H5 (ammonium aniline dithiocarbamate). The reaction of 1,1,2,3,4,5,6-heptahydro-1-iodo-1-(morpholine dithiocarbamato) tellurane [C5H10TeI(S2CNC4H8O)] (10) with 1,10-phenanthroline gives an unusual product C12H8N2 · C4H10INO (11). The structures of the new complexes 2, 8, 9, 10 and 11 have been determined by the X-ray analysis. 相似文献