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91.
In the present study, the influence of aluminium (Al) addition on the martensite-austenite phase transformation and exchange bias of Ni–Mn–Sb films have been investigated. Ni–Mn–Sb–Al films with different Al concentration (∼0–5.6%) were deposited by co-sputtering of Ni–Mn–Sb and Al targets. Experimental results revealed the decrease in martensitic transformation temperature with increasing Al content upto a certain extent (3.3%) beyond which martensitic transformation was suppressed. Paramagnetic to ferromagnetic transition temperature (TC) also decreased with increasing Al concentration. Ni50Mn36.3Sb10.4Al3.3 thin film showed significant improvement in exchange bias field as compared to pure Ni50.3Mn36.9Sb12.8 thin film. This enhancement in the exchange bias field HEB = 611 Oe at 10 K is attributed to the increase of AFM-FM interactions that result from the decrease of Mn–Mn distance due to the incorporation of Al atoms. This behaviour is an additional property of the FSMA thin films apart from various other multifunctional properties and therefore, is of technological importance for their applications in magnetic storage devices. 相似文献
92.
Sabir H. Mashraqui Rupesh Betkar Sushil Ghorpade Antonio Frontera 《Journal of inclusion phenomena and macrocyclic chemistry》2013,76(3-4):293-300
We have designed and synthesized a new chemodosimeter, Benzolin-A, which selectively responds to toxic cyanide by dual colorimetric and fluorescence turn-on responses in buffered aqueous DMSO. In the presence of cyanide, we observe absorbance red shift of 108 nm (color changing from colorless to yellow) and fivefold fluorescence enhancement. The 1H NMR studies confirm the nucleophilic addition mechanism, and consistent with the experimental findings, the computational work predicts the feasibility of photoelectron transfer or energy transfer process in the native probe, as well as enhanced internal charge transfer in the Benzolin-A-cyanide adduct. Noteworthily, several background anions, such as F?, Cl?, AcO?, SCN?, HSO4 ?, NO3 ?, Br?, I? and H2PO4 ? exhibit none or insignificant optical perturbations. 相似文献
93.
Alan H. Cowley Jan E. Kilduff Jonathan G. Lasch Sushil K. Mehrotra Nicholas C. Norman Marek Pakulski 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-3):3-6
Abstract The synthesis of diphosphenes (RP[dbnd]PR′), phosphaarsenes (RPxydAsR′), phosphastibenes (RP[dbnd]SbR′), and diarsenes (RAs[dbnd]AsR′) is discussed. X-ray crystallographic studies have been performed on representative double-bonded compounds. The reactivities and coordination chemistry of selected compounds have been explored. 相似文献
94.
Neeraj Dwivedi Sushil Kumar H.K. MalikGovind C.M.S. RauthanO.S. Panwar 《Applied Surface Science》2011,257(15):6804-6810
In the present work the correlation of electrical, optical and nano-mechanical properties of argon-diluted diamond-like carbon (Ar-DLC) thin films with sp3 and sp2 fractions of carbon have been explored. These Ar-DLC thin films have been deposited, under varying C2H2 gas pressures from 25 to 75 mTorr, by radio frequency-plasma enhanced chemical vapor deposition technique. X-ray photoelectron spectroscopy studies are performed to estimate the sp3 and sp2 fractions of carbon by deconvoluting C 1s core level spectra. Various electrical, optical and nano-mechanical parameters such as conductivity, I-V characteristics, optical band gap, stress, hardness, elastic modulus, plastic resistance parameter, elastic recovery and plastic deformation energy have been estimated and then correlated with calculated sp3 and sp2 fractions of carbon and sp3/sp2 ratios. Observed tremendous electrical, optical and nano-mechanical properties in Ar-DLC films deposited under high base pressure conditions made it a cost effective material for not only hard and protective coating applications but also for electronic and optoelectronic applications. 相似文献
95.
Sunil Rohilla Sushil KumarP. Aghamkar S. SunderA. Agarwal 《Journal of magnetism and magnetic materials》2011,323(7):897-902
Magnetic nanocomposites consisting of cobalt ferrite nanoparticles embedded in silica matrix were prepared by the coprecipitation method using metallic chlorides as precursors for ferrite. Subsequently composites were annealed at 100, 200 and 300 °C for 2 h. The samples were structurally characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). The magnetic properties were measured in the temperature range of 10-300 K using vibrating sample magnetometer (VSM). The effects of thermal treatment on structural and magnetic properties of nanocomposites were investigated. When the samples were annealed, CoFe2O4 nanocrystallites were observed in the SiO2 matrix, whose size increases with increase in annealing temperature. The coercivity and saturation magnetization of nanocomposite (annealed at 300 °C for 2 h) are much higher than that of bulk cobalt ferrite. The realization of adjustable particle sizes and controllable magnetic properties makes the applicability of the CoFe2O4 nanocomposite more versatile. 相似文献
96.
Development of molecularly imprinted microspheres for the fast uptake of 4‐cumylphenol from water and soil samples
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Priyanka Narula Varinder Kaur Raghubir Singh Sushil Kumar Kansal 《Journal of separation science》2014,37(22):3330-3338
Molecularly imprinted microspheres containing binding sites for the extraction of 4‐cumylphenol have been prepared for the first time. The imprinted microspheres were synthesized by a precipitation method using 4‐cumylphenol as a template molecule, methacrylic acid as a functional monomer and divinylbenzene‐80 as a cross‐linker for polymer network formation. The formation and the morphology of molecularly imprinted microspheres were well characterized using infrared spectroscopy, thermogravimetric studies, and scanning electron microscopy. The Brunauer–Emmett–Teller analysis revealed the high surface area of the sorbent indicating formation of molecularly imprinted microspheres. The developed microspheres were employed as a sorbent for the solid‐phase extraction of 4‐cumylphenol and showed fast uptake kinetics. The sorption parameters were optimized to achieve efficient sorption of the template molecule, like pH, quantity of molecularly imprinted microspheres, time required for equilibrium set‐up, sorption kinetics, and adsorption isotherm. A standard method was developed to analyze the sorbed sample quantitatively at 279 nm using high‐performance liquid chromatography with diode array detection. It was validated by determining target analyte from synthetic samples, bottled water, spiked tap water, and soil samples. The prepared material is a selective and robust sorbent with good reusability. 相似文献
97.
98.
The stem bark and wood of Berberis aristata DC (Daruharidra) are one of the principal ingredients of traditional skin lighting and exfoliating scrub preparation in India. The standardised extract of B. aristata was screened to evaluate their in vitro antityrosinase activity and inhibition kinetics. Phytochemical and pharmacological studies were carried out with different solvent fractions of the methanol extract of B. aristata (MEBA). RP-HPLC analysis was used to determine the berberine content in extract and fractions of B. aristata. MEBA showed maximum berberine content. Extract and fractions of B. aristata contain the maximum amount of alkaloids than other constituents. In tyrosinase inhibition assay, MEBA was found to possess highest dose-dependent monophenolase and moderate diphenolase activity. The enzyme kinetic study revealed that MEBA possessed mixed type inhibition of monophenolase activity of tyrosinase. These bioactivities indicate that the MEBA has antihyperpigmentation potential in human skin. 相似文献
99.
The transformation of aldehydes into terminal olefins through reduction of the corresponding enol triflates is described. The method is effective with both linear and alpha-branched aldehydes. 相似文献
100.
In recent years, a variety of new designs of coronene-based polycyclic aromatic hydrocarbons (PAHs) with diverse functions have emerged to serve as complementary materials in organic chemistry and materials chemistry. In the present review, we highlight the modern aspects of syntheses related to or different from the strategies used in the early era of coronene research. Systematic extension and expansion of coronene backbones to wide categories of angular PAHs are covered. The substitution and extension of coronene architectures, by incorporating functional groups and by fusing small and large conjugated units, advatangeously enrich their photophysical, electrochemical, self-assembling, and other properties, of which are discussed to demostrate their impact in materials chemistry. While the highly symmetric coronenes, tribenzocoronenes and hexabenzocoronenes conceived wide potential in charge-transporting, electroluminescent, sensing, and other applications, other related derivatives such as dibenzo, tetrabenzo and pentabenzocoronenes also displayed their potentials as exemplified by their use as charge-conduction channel in transistor application. 相似文献