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51.
R.B. Shinde N.S. Padalkar S.V. Sadavar A.S. Patil S.B. Kale V.V. Magdum Y.M. Chitare S.P. Kulkarni U.M. Patil V.G. Parale J.L. Gunjakar 《Materials Today Chemistry》2022
Tuning the interior chemical composition of layered double hydroxides (LDHs) via lattice engineering route is a unique approach to enable multifunctional applications of LDHs. In this regard, the exfoliated 2D LDH nanosheets coupled with various guest species lead to the lattice-engineered LDH-based multifunctional self-assembly with precisely tuned chemical composition. This article reports the synthesis and characterization of mesoporous zinc–chromium-LDH (ZC-LDH) hybridized with isopolyoxovanadate nanohybrids (ZCiV) via lattice-engineered self-assembly between delaminated ZC-LDH nanosheets and isopolyoxovanadate (iPOV) anions. Electrostatic self-assembly between 2D ZC-LDH monolayers and 0D iPOV significantly altered structural, morphological, and surface properties of ZC-LDH. The structural and morphological study demonstrated the formation of mesoporous interconnected sheet-like architectures composed of restacked ZCiV nanosheets with expanded surface area and interlayer spacing. In addition, the ZCiV nanohybrid resistive elements were used as a room-temperature gas sensor. The selectivity of ZCiV nanohybrid was tested for various oxidizing (SO2, Cl2, and NO2) gases and reducing (LPG, CO, H2, H2S, and NH3) gases. The optimized ZCiV nanohybrid demonstrated highly selective SO2 detection with the maximum SO2 response (72%), the fast response time (20 s), low detection limit (0.1 ppm), and long-term stability at room temperature (27 ± 2 °C). Of prime importance, ZCiV nanohybrids exhibited moderately affected SO2 sensing responses with high relative humidity conditions (80%–95%). The outstanding SO2 sensing performance of ZCiV is attributed to the active surface gas adsorptive sites via plenty of mesopores induced by a unique lattice-engineered interconnected sheet-like microstructure and expanded interlayer spacing. 相似文献
52.
Molecular Diversity - The oxidation of benzylic alcohol to corresponding aldehyde and ketone using N-chlorosuccinimide (NCS)–N,N-dimethylformamide (DMF) has been described. This method gives... 相似文献
53.
54.
Determination of palladium in synthetic nuclear wastes by differential pulse voltammetry 总被引:1,自引:0,他引:1
V. T. Aher M. M. Palrecha A. V. Kulkarni G. C. Shah 《Journal of Radioanalytical and Nuclear Chemistry》2002,252(3):573-576
A novel method for the determination of palladium in synthetic nuclear waste samples has been developed using a computerized voltammetric analyzer. The electrode system consists of hanging mercury drop electrode (HMDE)/glassy carbon/Ag-AgCl electrode. Various experimental conditions including electrolyte type, pH and concentration have been optimized, leading to a detection limit of 40 ng/ml. The mixture of 4.10-3M citric acid + 2.10-2M ammonia-ammonium chloride buffer + 4.10-3M EDTA was used as a supporting electrolyte at pH 9.0. Standard addition method was employed to determine the concentration of palladium present in the nuclear waste sample. The relative standard deviation of the proposed method was found to be 8% at 40 ng/ml of palladium content. The method is direct, simple, rapid and free from any possible interference. 相似文献
55.
A procedure which incorporates the aspects of both correction matrix and digital filtering to compensate for sensitivity fall-off of the surface coil has been applied to clinical imaging. In this method the surface coil profile is determined using the surface coil image and a crude body coil image. Our results indicate that the corrected surface coil image exhibits the homogeneity of the body coil image while essentially preserving the sensitivity of the surface coil image. 相似文献
56.
The magnetic properties of the spinel series GexCu1?xFe2O4 (X = 0 to 0.8) have been investigated by means of Mössbauer spectroscopy. Mössbauer spectra for X = 0.0 to 0.6 suggest the existence of two hyperfine fields, one due to the Fe3+ tetrahedral ions (A-sites) and the other due to Fe3+ octahedral ions (B-sites), while for X = 0.8 it shows the superposition of hyperfine field split spectra from A- and B-site ions and a broad central line spectrum. For 0.2 ? X ? 0.4, fast electron exchange among octahedral iron ions occurs as in Fe3O4. The variations of nuclear magnetic fields at the A- and B-sites are explained on the basis of AB and BB supertransferred hyperfine interactions. 相似文献
57.
Theoretical natural frequencies and modal shapes of the first five modes of vibration are presented for a rotating blade of asymmetric aerofoil cross section, with allowance for shear deflection and rotary inertia. Frequency equations for a rotating blade with asymmetry in one plane are developed by using the Ritz process, in two ways: namely, by proceeding according to the Reissner method and according to the classical potential energy method. In both cases shape functions for the bending moment, shearing force, twisting moment, bending slope, elastic twist and deflection are developed in series form. The results obtained are compared with those existing in the literature; it is found that the Reissner method approach yields more rapid convergence than does the classical potential energy method. 相似文献
58.
J. K. Srivastava G. Jéhanno K. Muraleedharan J. A. Kulkarni V. R. Marathe V. S. Darshane R. Vijayaraghavan 《Hyperfine Interactions》1986,28(1-4):519-523
Mössbauer measurements in mixed spinel ferrite Gax Fe1–x Ni Cr O4 (0x0.8), carried out between 4.2 and 298°K, show the presence of entropic spins in this system. Recent Monte Carlo calculations /4/ have predicted the presence of such spins in a frustrated spin glass lattice. 相似文献
59.
Magnetic metal and metal oxide nanoparticles capped with alkylamines have been synthesized and characterized by transmission
electron microscopy. X-ray diffraction, energy dispersive X-ray analysis and magnetization measurements. Core-shell Pd-Ni
particles with composition, Pd561Ni3000, (diameter ∼3.3 nm) are superparamagnetic at 5 K and organize themselves into two-dimensional crystalline arrays. Similar
arrays are obtained with Pd561Ni3000Pd1500 nanoparticles containing an additional Pd shell. Magnetic spinel particles of γ-Fe2O3, Fe3O4 and CoFe2O4 of average diameters in the 4–6 nm range coated with octylamine are all supermagnetic at room temperature and yield close-packed
disordered arrays. Relatively regular arrays are formed by dodecylaminecapped Fe3O4 nanoparticles (∼8.6 nm diameter) while well-ordered hexagonal arrays were obtained with octylamine-covered Co3O4 nanoparticles (∼4.2 nm diameter). 相似文献
60.
D. V. R. Raju V. J. Rao S. Badrinarayanan A. B. Mandale S. K. Kulkarni 《Applied Physics A: Materials Science & Processing》1990,50(3):339-342
X-ray photoelectron spectroscopy (XPS) together with argon ion sputtering was used to investigate the interface of the Zn/CdSnAs2 system at various temperatures. The formation of an intermediate compound between Zn and As is proposed. The surface enrichment of Cd and Sn at 200 and 400°C is explained in terms of bond breaking and lattice strain theories.NCL Communication No. 4352 相似文献