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31.
Ram Manohar Yadav Dinesh Pratap Singh T. Shripathi O. N. Srivastava 《Journal of nanoparticle research》2008,10(8):1349-1354
We report the observations made on the synthesis and characterization of C–N nanotube blocks and Y-junctions in bamboo-like
C–N nanotubes. The C–N nanotube Blocks have been synthesized by pyrolyzing the mixture of silver nitrate acetonitrile solution
and ferrocene benzene solution. The structural/microstructural characterization of the as-synthesized material has been done
using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). X-ray photoelectron spectroscopic (XPS)
analysis has been carried out to confirm the presence of nitrogen in nanotubes. These investigations reveal the formation
of blocks of bamboo-like nanotubes having the dimension 300 × 200 × 30 μm and the diameter is 20–50 nm. We also observe the
formation of Y-junctions in bamboo-like nanotubes as we spray the acetonitrile ferrocene and AgNO3 mixture. The length of the synthesized Y-junction nanotube bundles is ~2 μm. Some more complex Ψ-shaped junctions are also
found to be present. The diameters of the Y-junction nanotubes is ~80 nm at the junction and 25–50 nm at the branches. 相似文献
32.
The paper reports a structural study of some memory and threshold chalcogenides in terms of coordination numberC, defined byC=8−N, and is the average coordination number for covalently bonded materials. The average number of nearest neighbours surrounding
a central atom, obtained for As-Ge-Te (memory) and Se-Ge-Te (threshold) systems have been used to estimate the cohesive energies,
assuming simple additivity of bond energies. The bonding pattern so obtained, explains certain properties of these glasses. 相似文献
33.
34.
The ratio of the B+ B- and B0B0 production rates in e+ e- annihilation is computed as a function of the B meson velocity and BB*pi coupling constant, using a nonrelativistic effective field theory. 相似文献
35.
The top-quark cross section close to threshold in e(+)e(-) annihilation is computed including the summation of logarithms of the velocity at next-to-next-to-leading-logarithmic order in QCD. The remaining theoretical uncertainty in the normalization of the total cross section is at the few-percent level, an order of magnitude smaller than in previous next-to-next-to-leading order calculations. This uncertainty is smaller than the effects of a light standard-model Higgs boson. 相似文献
36.
37.
Gunjan Verma V. K. Aswal S. K. Kulshreshtha C. Manohar P. A. Hassan Eric W. Kaler 《Pramana》2008,71(5):997-1002
Structural parameters of micelles formed by Triton X-100 in the presence of solubilized anthranilic acid at different pH values
was investigated using light scattering and small angle neutron scattering. Analysis of the SANS data indicate that micelles
are oblate ellipsoidal in nature with little variation in the dimensions, in the investigated pH range (from 0.5 to 6.0).
The interaction potential of the micelles shows a minimum closer to the isoelectric point of anthranilic acid. A similar variation
is observed in the cloud point of the micelles with pH. The observed variation in the interaction potential with pH of the
micellar solution can be explained in terms of the reversal of charge on anthranilic acid due to shift in the acid-base equilibrium.
The variation in interaction potential and cloud point with pH is modelled using Coulombic repulsion of charged molecules
at the micelle interface.
相似文献
38.
Rajesh G. Kalkhambkar Geeta M. Kulkarni Jagannath C. Kadakol G. Aridoss Yeon Tae Jeong Manohar V. Kulkarni 《Journal of heterocyclic chemistry》2013,50(5):1108-1115
A synthesis, characterization, and antimicrobial study of a novel benzodipyran analog of chloramphenicol was carried out. Structure–antimicrobial activity relationship study indicates that benzodipyran analog of chloramphenicol was most active against Gram‐positive bacteria, Staphylococcus aureus, and the fungal strains Rhizoctonia bataticola and Penicillium even at minimum inhibitory concentration 10 µg/mL and showed moderate activity in other bacterial and fungal organisms. All the compounds synthesized during the present investigation were characterized by IR, 1H NMR, 13C NMR, ESI‐MS, and elemental analysis. 相似文献
39.
A. Dakshinamoorthy T. Kumar K. K. Nandy R. H. Iyer J. N. Mathur S. B. Manohar 《Journal of Radioanalytical and Nuclear Chemistry》2000,245(3):595-598
In a preliminary study performed with the waste rocks from the future uranium mine to be explored in Brazil, 106 samples were taken from the eight main lithologies found in the massif and analysed by instrumental neutron activation analysis (INAA) for 20 elements. For samples from the same lithology, a high variability in the concentration of most of the elements was found (coefficient of variation larger than 20%), which might be attributed to either insufficient homogenisation of minerals or to local variation within lithology. The hypothesis that the variability within the lithology does not have an influence to the total variability was tested by analysing 5 replicates of the 5 most contrasting samples from the predominant lithology (plagioclase-microcline-gneiss), chosen after applying statistical evaluation (principal components and cluster analyses). Results indicated that homogenisation of samples was adequate due to low variation among replicates. The hypothesis tested was rejected with a confidence level higher than 99% for all the elements, corroborating the large intra-lithology variability. 相似文献
40.
Techniques used for the measurement of independent and cumulative fission yields are reviewed in this article. 相似文献