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61.
Subhadip Biswas Rohitashwa Chattopadhyay Jayanta K Bhattacharjee 《Physics letters. A》2018,382(18):1202-1206
We consider the dynamics of a particle in a parametric oscillator with a view to exploring any quantum feature of the initial wave packet that shows divergent (in time) behaviour for parameter values where the classical motion dynamics of the mean position is bounded. We use Ehrenfest's theorem to explore the dynamics of nth order moment which reduces exactly to a linear non autonomous differential equation of order . It is found that while the width and skewness of the packet is unbounded exactly in the zones where the classical motion is unbounded, the kurtosis of an initially non-gaussian wave packet can become infinitely large in certain additional zones. This implies that the shape of the wave packet can change drastically with time in these zones. 相似文献
62.
Bimal P. Singh Jayadev Jena Laxmidhar Besra Sarama Bhattacharjee 《Journal of nanoparticle research》2007,9(5):797-806
The dispersion characteristics of nanosize silicon carbide (SiC) suspension were investigated in terms of surface charge,
particle size, rheological measurement and adsorption study. Ammonium polycarboxylate has been used as dispersant to stabilize
the suspension. It was found that the isoelectric point (iep) of SiC powder was pHiep (4.9). The surface charge of powder changed significantly in presence of the ammonium polycarboxylate dispersant and iep
shifted significantly towards lower acidic pH (3.6). The shift in iep has been quantified in terms of ΔG
0
SP, the specific free energy of adsorption between the surface sites and the adsorbing polyelectrolyte (APC). The values of
ΔG
0
SP (−10.85 RT unit) estimated by the electro kinetic data compare well with those obtained from adsorption isotherms (−9.521 RT unit). The experimentally determined optimum concentration of dispersant required for maximizing the dispersion was found
to be 2.4 mg/g of SiC (corresponding to an adsorbed amount of 1.10 mg/g), at pH 7.5. This is much below the full monolayer
coverage (corresponding to adsorbed amount of 1.75 mg/g) of the particles surface by the dispersant. The surface charge quantity,
rheological, pH, electro kinetic and adsorption isotherm results were used to explain and correlate the stability of the nanosize
silicon carbide in aqueous media. At pH 7.5, where both SiC surface and APC are negatively charged, the adsorption of APC
was low because of limited availability of favourable adsorption sites. In addition, the brush-like configuration of the adsorbed
polymer prevented close approach of any additional dispersant; hence stabilization of the slurry happens at a comparatively
lower concentration than the monolayer coverage. 相似文献
63.
Abachi S Abbott B Abolins M Acharya BS Adam I Adams DL Adams M Ahn S Aihara H Alitti J Álvarez G Alves GA Amidi E Amos N Anderson EW Aronson SH Astur R Avery RE Baden A Balamurali V Balderston J Baldin B Bantly J Bartlett JF Bazizi K Bendich J Beri SB Bertram I Bezzubov VA Bhat PC Bhatnagar V Bhattacharjee M Bischoff A Biswas N Blazey G Blessing S Boehnlein A Bojko NI Borcherding F Borders J Boswell C Brandt A Brock R Bross A Buchholz D Burtovoi VS Butler JM Casey D Castilla-Valdez H 《Physical review letters》1995,75(6):1023-1027
64.
Ajay K. Bose Subhendu N. Ganguly Maghar S. Manhas Vaidyanathan Srirajan Ashoke Bhattacharjee Sochanchingwung Rumthao Anju H. Sharma 《Tetrahedron letters》2004,45(6):1179-1181
A novel dinitro secondary metabolite, 2-nitro-4-(2′-nitroethenyl)phenol from a marine source, has been prepared via highly accelerated, microwave assisted, nitration reactions using mild reagents. ipso-Substitution of a carboxy group by a nitro group is discussed. 相似文献
65.
Sudip K. De Manish Bhattacharjee 《Journal of polymer science. Part A, Polymer chemistry》2011,49(18):3920-3927
An early transition metal metallocene compound, Cp2ZrCl2, with an anionic surfactant, sodium n‐dodecyl sulfate (SDS) as emulsifier and NaBPh4 as cocatalyst has been found to be an effective catalytic system for polymerization and copolymerization of monomers like styrene and methyl methacrylate in aqueous medium. The diameters of the latex particles were found to be in between 20 and 40 nm. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 相似文献
66.
We introduce a single step memory dependence in the fully chaotic logistic map. This makes it a two dimensional system in general. However, we show that by using composite functions to define two one dimensional maps, it is possible to obtain some analytic results for the bifurcation structure. Numerical results support the calculated bifurcation scheme and, in addition, yield a further insight which allows the calculation of the convergence ratio for a new period adding scenario. 相似文献
67.
Estrogen induced proliferation of existing mutant cells is widely understood to be the major risk determining factor in the
development of breast cancer. Hence determination of the Estrogen Receptor[ER] status is of paramount importance. We have
carried out the synthesis and characterization of a novel NIR fluorescent dye conjugate aimed at measuring ER+ve status in-vivo.
The conjugate was synthesized by ester formation between 17-β estradiol and a cyanine dye namely: bis-1, 1-(4-sulfobutyl)
indotricarbocyanine-5-carboxylic acid, sodium salt. The replacement of the sodium ion in the ester by a larger glucosammonium
ion was found to enhance the hydrophilicity and reduce the toxic effect on cell lines. The excitation and emission peaks for
the dye were recorded as 750 and 788 nm respectively; ideal for non-invasive optical imaging owing to minimal tissue attenuation
and auto-fluorescence at these wavelengths. The dye (NIRDC1) has a significant drop in plasma-protein binding therefore leading to marked improvement in pharmacokinetic profile such
as dye evacuation in comparison to ICG. In addition the dye showed enhanced fluorescence quantum yield, molar extinction coefficient
and linearity in fluorescence relative to ICG. This dye can be potentially used as a target specific exogenous contrast agent
in molecular optical imaging for early detection of breast cancer. 相似文献
68.
Biswajit GhoshRupanjali Bhattacharjee Pushan BanerjeeSubrata Das 《Applied Surface Science》2011,257(8):3670-3676
In this work, 650 nm polycrystalline SnS thin films were grown by thermal evaporation of high purity tin sulfide powder at 250 °C substrate temperature, followed by post deposition annealing at 200 °C and 300 °C for 2, 4 and 6 h, and at 400 °C for 2 and 4 h in argon ambient. The XRD pattern of the as-deposited and annealed SnS films led to the conclusion that the as-deposited films were polycrystalline in nature with preferentially oriented along (1 1 1) direction. The direct bandgap of all the films was found to be observed between 1.33 and 1.53 eV. Except for annealing at 400 °C all the films were nearly stoichiometric in nature, suggesting lower rate of desulfurization at that ambient. However, higher annealing temperature has resulted in the segregation of tin phase. All the films showed good absorption in the visible range. The as-deposited and annealed films showed p-type conductivity. Hall measurement revealed the carrier concentration and mobility ranging from 1015 to 1016 cm−3 and 0.8 to 31.6 cm2 V−1 s−1 respectively. The photoconductivity measurements of all the SnS films were carried out by recording the lowering of resistance of the respective films with time under illumination. 相似文献
69.
Shashaank Gupta Shuvrajyoti Bhattacharjee Dhananjai Pandey Vipul Bansal Suresh K. Bhargava Ju Lin Peng Ashish Garg 《Applied Physics A: Materials Science & Processing》2011,104(1):395-400
We report an unusual behavior observed in (BiFeO3)1−x
–(PbTiO3)
x
(BF–xPT) thin films prepared using a multilayer chemical solution deposition method. Films of different compositions were grown
by depositing several bilayers of BF and PT precursors of varying BF and PT layer thicknesses followed by heat treatment in
air. X-ray diffraction showed that samples of all compositions show mixing of two compounds resulting in a single-phase mixture,
also confirmed by transmission electron microscopy. In contrast to bulk compositions, samples show a monoclinic (MA-type) structure suggesting disappearance of the morphotropic phase boundary (MPB) at x=0.30 as observed in the bulk. This is accompanied by the lack of any enhancement of the remanent polarization at the MPB,
as shown by the ferroelectric measurements. Magnetic measurements showed an increase in the magnetization of the samples with
increasing BF content. Significant magnetization in the samples indicates melting of spin spirals in the BF–xPT films, arising from a random distribution of iron atoms. Absence of Fe2+ ions was corroborated by X-ray photoelectron spectroscopy measurements. The results illustrate that thin film processing
methodology significantly changes the structural evolution, in contrast to predictions from the equilibrium phase diagram,
besides modifying the functional characteristics of the BP-xPT system dramatically. 相似文献
70.
Papiya Bhattacharjee 《Topology and its Applications》2011,158(14):1802-1814
In studying the minimal prime spectra of commutative rings with identity we have been able to identify several interesting types of extensions of rings. In particular, we determine what kind of ring extensions will result in a homeomorphisms of the hull-kernel and inverse topologies on the minimal prime spectra. We relate these types of extensions to other known types of extensions. 相似文献