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511.
Sudhir K Vempati 《Pramana》2000,55(1-2):277-282
It has been known for sometime that supersymmetric theories with R-parity violation provide a natural framework where small neutrino masses can be generated. We discuss neutrino masses and
mixing in these theories in the presence of trilinear lepton number violating couplings. It will be shown that simultaneous
solutions to solar and atmospheric neutrino problems can be realized in these models. 相似文献
512.
513.
514.
Sudhir R. Jain 《Pramana》2009,72(3):611-615
We construct the expression for the ground state eigenfunction of the Schrödinger equation for a particle inside an arbitrary planar triangle under the influence of a potential. 相似文献
515.
We calculate the electric dipolarizability of 7Li nucleus within the cluster model and estimate a value of about 0.0188 fm3. We also discuss the possibility of observing this in the scattering of 7Li from a 208Pb target at energies about 30 MeV.
相似文献
516.
Nicholas Leventis Sudhir Mulik Xiaojiang Wang Amala Dass Vishal U. Patil C. Sotiriou-Leventis Hongbing Lu Gitogo Churu Alex Capecelatro 《Journal of Non》2008,354(2-9):632-644
Macroporous (1–5 μm) monolithic silica aerogels consisting of both random but also ordered mesoporous walls have been synthesized via an acid-catalyzed sol–gel process from tetramethoxysilane (TMOS) using a triblock co-polymer (Pluronic P123) as a structure-directing agent and 1,3,5-trimethylbenzene (TMB) as a micelle-swelling reagent. Pluronic P123 was removed by Soxhlet extraction, and materials in monolithic form were obtained by extracting the pore filling solvent with liquid CO2, which eventually was taken out supercritically. Although these monoliths are more robust than base-catalyzed silica aerogels of similar density, nevertheless, the mechanical properties can be improved dramatically by letting an aliphatic di-isocyanate (Desmodur N3200) react with the silanols on the macro- and mesoporous surfaces. As it turns out, the polymer fills the mesopores and coats conformally the macropores of templated samples, so that BET surface areas decrease dramatically, from 550–620 m2 g?1 to <5 m2 g?1. By comparison, polymer nano-encapsulation of non-templated acid-catalyzed aerogels preserves a large fraction of their mesoporous surface area, and BET values decrease from 714 m2 g?1 to 109 m2 g?1. Finally, since polymer nano-encapsulation preserves the macroscopic physical dimensions of the monoliths before drying, comparative analysis of the physical dimensions against XRD data of native versus polymer nano-encapsulated samples provides evidence that upon drying macropores (micron size regime) shrink less than mesopores (nanometer size regime). 相似文献
517.
Ashish Dhamsaniya Shahrukh Khan Safi Pratiksha Chhatbar Prachi Trivedi Kaushik Pambhar Vaibhav Mehta Anamik Shah 《Tetrahedron letters》2019,60(4):362-365
An unprecedented metal-free synthesis of 4-(methylthio)chromeno[4,3-c]pyrazol-3(2H)-one is reported via sequential one-pot desulfitative [5+1] hetero-annulation. The present strategy consists of one-pot sequential, base catalysed dithioketene formation from active methylene of pyrazolone followed by methylation and [5+1] heteroannulative cyclization. The resulting substrate undergoes facile nucleophilic substitution with various amines to yield 4-(substituted-amine)-chromeno[4,3-c]pyrazol-3(2H)-one derivatives under metal free condition. 相似文献
518.
Awantika Singh Pratibha Singh Sudhir Kumar Kapil Dev Rakesh Maurya 《Natural product research》2019,33(15):2253-2256
Spinacia oleracea L. (Spinach) is a leafy vegetable which is considered to have a high nutritional value. Flavonoids in spinach were reported to act as antimutagenic property. Rapid detection of these flavonoids in Spinach was achieved by using HPLC-ESI-QTOF-MS/MS. Thirty six compounds were tentatively identified based on their retention times, accurate mass and MS/MS spectra. The fragmentation patterns of known compounds were applied to elucidate the structure of their corresponding derivatives having the same basic skeleton. Out of thirty six peaks, three peaks were assigned as patuletin and six peaks were assigned as spinacetin derivatives. Twelve compounds were first time identified following the fragmentation pattern of known compounds. Five of the identified compounds i.e., spinacetin, 5,3′,4′-trihydroxy-3-methoxy-6,7-methylenedioxyflavone, protocatechuic acid, ferulic acid and coumaric acid were simultaneously quantified in spinach leaves by a validated UPLC-ESI-MS/MS method under MRM mode. 相似文献
519.
The nuclear shell model is (over)viewed with examples from its early phase to its current status. 相似文献
520.
Acta Mathematica Hungarica - 相似文献