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101.
Sudip Nath Sujit Kumar Ghosh Subrata Kundu Snigdhamayee Praharaj Sudipa Panigrahi Tarasankar Pal 《Journal of nanoparticle research》2006,8(1):111-116
A detailed comparison of the softness of gold and silver has been reported in the light of hard soft acid base (HSAB) principle. Gold and silver nanoparticles in organic media (i.e., organosol) have been exploited individually to establish the principle. Sulfur and nitrogen were employed as soft and borderline donating atoms to examine the metal-ligand interactions. In this regard, thiols and amines have been considered as interacting ligands with sulfur and nitrogen donor atoms respectively. The stronger affinity of gold towards softer sulfur donor as compared to nitrogen and conversely a reasonable interaction of silver nanoparticles with both the atoms authenticate the softer nature of gold nanoparticle as compared to silver one. 相似文献
102.
Several supergravity solutions corresponding to bothDp, as well asDp—Dp′ systems, inNS-NS andR-R pp-wave background originating fromAdS
3 xS
3 xR
4 are presented. The supersymmetry properties of these solutions are analysed along with a brief outline of the world sheet
construction for thep — p′ branes. 相似文献
103.
N. Suriyamurthy B. S. Panigrahi K. Dukenbayev Annapurna Rout S. K. Sekatskii G. Dietler 《辐射效应与固体损伤》2013,168(2):146-152
Photostimulable phosphor CsBr:Eu2+ is prepared through a solid-state reaction. The effect of annealing atmosphere on photoluminescence and photostimulated luminescence was investigated. Optimum luminescence intensity was obtained when samples were prepared at 350°C in air atmosphere. The effect of irradiation of gamma and neutron had resulted in the formation of optically stimulable traps with different trap depths. The role of monovalent and divalent dopants on thermoluminescence dosimetric properties has been discussed. 相似文献
104.
This paper presents the application of surface-bonded piezo-transducers for damage assessment of tensegrity structures through dynamic strain measurement and electro-mechanical impedance (EMI) technique. The two techniques are first applied on a single module tensegrity structure, 1 m×1 m in size and their damage diagnosis results compared. A single piezoelectric-ceramic (PZT) patch bonded on a strut measures the dynamic strain during an impact excitation of the structure. Damage is identified from the changes in global frequencies of the structure obtained from the PZT patch’s response. This is compared with the damage identified using the EMI technique, which is a signature based technique and operates at frequencies of the order of kHz. The dynamic strain approach, which requires commonly available hardware, is found to exhibit satisfactory performance vis-à-vis the EMI technique for damage assessment of tensegrity structures. The damage diagnosis exercise is then extended to a tensegrity grid structure, 2 m×2 m size, fabricated using galvanized iron (GI) pipes and mild steel wire ropes. The damage is localized using changes in natural frequencies observed experimentally using the dynamic strain approach and the corresponding mode shapes of the undamaged structure derived numerically. The dynamic strain approach is found to be very expedient, displays competitive performance and is at the same time cost effective for damage assessment of tensegrity structures. 相似文献
105.
Priyadarshini S. Sahoo Anuradha Panigrahi Sunanda K. Patri Ram N. P. Choudhary 《Central European Journal of Physics》2008,6(4):843-848
Polycrystalline samples of Ba4SrRTi3V7O30 (R=Sm and Dy), members of the tungsten-bronze family, were prepared using a high-temperature, solid-state reaction technique
and studied their electrical properties (using complex impedance spectroscopy) in a wide range of temperature (31–500°C) and
frequency (1 kHz-1 MHz). Preliminary structural (XRD) analyses of these compounds show the formation of single-phase, orthorhombic
structures at room temperature. The scanning electron micrographs (SEM) provided information on the quality of the samples
and uniform distribution of grains over the entire surface of the samples. Detailed studies of the dielectric properties suggest
that they have undergone ferroelectric-paraelectric phase transition well above the room temperatures (i.e., 432 and 355°C
for R= Sm and Dy, respectively, at frequency 100 kHz). Measurements of electrical conductivity (ac and dc) as a function of
temperature suggest that the compounds have semiconducting properties much above the room temperature, with negative temperature
coefficient of resistance (NTCR) behavior. The existence of ferroelectricity in these compounds was confirmed from a polarization
study.
相似文献
106.
C. David B. Sundaravel T.R. Ravindran K.G.M. Nair B.K. Panigrahi H.P. Lenka B. Joseph D.P. Mahapatra 《Applied Physics A: Materials Science & Processing》2007,88(2):397-400
Germanium atomic (Ge1
+) and molecular ions (Ge2
+) of equal energy per atom are implanted in silicon at an elevated temperature. The ion induced damage has been monitored
by following the intensity variation of the LO Raman peak of Si. The germanium implanted samples have been labeled with 10 keV
Au ions. The gettering of gold has been observed by Rutherford backscattering spectrometry in the post-annealed samples. This
paper reports a first time observation of an enhanced gettering of gold in silicon implanted with molecular ions.
PACS 61.72.Ji; 61.80.Lj; 61.80.Jh; 61.72.Yx 相似文献
107.
In this paper, we determine the full normalized Laplacian spectrum of the subdivision-vertex corona, subdivision-edge corona, subdivision-vertex neighbourhood corona and subdivision-edge neighbourhood corona of a connected regular graph with an arbitrary regular graph in terms of their normalized Laplacian eigenvalues. Moreover, applying these results, we find some non-regular normalized Laplacian cospectral graphs. 相似文献
108.
Panigrahi BS 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2000,(7):1337-1344
Fluorescence enhancement of Tb3+ has been studied, using substituted benzoic acids as ligands. These ligands enhance the fluorescence of Tb3+ by about three orders of magnitude. The enhancement is observed due to ligand sensitized fluorescence. The fluorescence of Tb3+ in these complexes is synergistically enhanced by the addition of trioctylphosphine oxide (TOPO) in Triton X-100. The synergism displayed by TOPO was observed only when Triton X-100 micellar medium was used. TOPO dissolved in SDS/DTAB micellar medium did not result in synergistic fluorescence enhancement of Tb3+. These observations are discussed in detail and the synergism displayed by TOPO is rationalized on the basis of the structure of the surfactants. 相似文献
109.
Bijaya Laxmi Panigrahi Gnaneshwar Nelakanti 《Journal of Applied Mathematics and Computing》2013,43(1-2):175-197
In this paper, we consider Galerkin method for weakly singular Fredholm integral equations of the second kind and its corresponding eigenvalue problem using Legendre polynomial basis functions of degree ≤n. We obtain the convergence rates for the approximated solution and iterated solution in weakly singular Fredholm integral equations of the second kind and also obtain the error bounds for the approximated eigenelements in the corresponding eigenvalue problem. We illustrate our results with numerical examples. 相似文献
110.
In this paper, oscillatory and asymptotic properties of solutions of nonlinear fourth order neutral dynamic equations of the form $(r(t)(y(t) + p(t)y(\alpha _1 (t)))^{\Delta ^2 } )^{\Delta ^2 } + q(t)G(y(\alpha _2 (t))) - h(t)H(y(\alpha _3 (t))) = 0(H)$ and $(r(t)(y(t) + p(t)y(\alpha _1 (t)))^{\Delta ^2 } )^{\Delta ^2 } + q(t)G(y(\alpha _2 (t))) - h(t)H(y(\alpha _3 (t))) = f(t),(NH)$ are studied on a time scale $\mathbb{T}$ under the assumption that $\int\limits_{t_0 }^\infty {\tfrac{t} {{r(t)}}\Delta t = \infty } $ and for various ranges of p(t). In addition, sufficient conditions are obtained for the existence of bounded positive solutions of the equation (NH) by using Krasnosel’skii’s fixed point theorem. 相似文献