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41.
Pooja Singla Manoj Sharma O. P. Pandey K. Singh 《Applied Physics A: Materials Science & Processing》2014,116(1):371-378
Undoped and Zn-doped TiO2 nanoparticles were synthesized by the sol gel method. The dopant (Zn) was taken at 0.1, 0.2, 0.5, 0.7, and 1.0 mol%. The initial precursors were titanium tetraisopropoxide and zinc acetate. The samples were characterized by X-ray powder diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, and UV–vis diffuse reflectance. The photocatalytic activity of the prepared nanoparticles was studied by observing their role in degradation of two azo dyes, i.e., Eriochrome Black T and Methyl Red under UV–visible light. The results revealed that Zn-doped TiO2 nanoparticles exhibited better degradation as compared to undoped TiO2 nanoparticles. In this study, 0.7 mol% Zn-doped TiO2 showed highest photocatalytic activity. Doping of Zn allowed better separation of electron–hole pairs which results in increased oxidation and reduction reactions. 相似文献
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43.
Muhammad Umer Faroque Sammer Yousuf Salman Zafar M. Iqbal Choudhary Maqsood Ahmed 《Acta Crystallographica. Section C, Structural Chemistry》2016,72(5):398-404
Biotransformation is the structural modification of compounds using enzymes as the catalysts and it plays a key role in the synthesis of pharmaceutically important compounds. 10β,17β‐Dihydroxy‐17α‐methylestr‐4‐en‐3‐one dihydrate, C19H28O3·2H2O, was obtained from the fungal biotransformation of methyloestrenolone. The structure was refined using the classical independent atom model (IAM) and a transferred multipolar atom model using the ELMAM2 database. The results from the two refinements have been compared. The ELMAM2 refinement has been found to be superior in terms of the refinement statistics. It has been shown that certain electron‐density‐derived properties can be calculated on the basis of the transferred parameters for crystals which diffract to ordinary resolution. 相似文献
44.
Satyan Choudhary Alfred J. Crosby 《Journal of polymer science. Part A, Polymer chemistry》2018,56(23):1545-1551
Evaporative self-assembly (ESA), based on the “coffee-ring” effect, is a versatile technique for assembling particle solutions into mesoscale patterns and structures on different substrates. ESA works with a wide variety of organic and inorganic materials, where the solution is a combination of volatile solvent and nonvolatile solute. Modified ESA methods, such as “stop-and-go flow coating,” use a programmed meniscus “stick–slip” motion to create mesoscale assemblies with controlled shape, size, and architecture. However, current methods are not scalable for increased production volumes or patterning large surface areas. We demonstrate a new ESA method, where an oscillating blade controls the meniscus depinning and drives the evaporative assembly of solutes at the pinned meniscus. Results show that oscillation frequency and substrate speed control time/distance intervals between successive meniscus depinning, and the assembly dimensions depend on solution concentration, oscillation frequency, substrate speed, and meniscus height. We report the mechanism of the meniscus depinning and the control over assembly cross-sectional dimensions. This advance provides a scalable ESA method with faster processing times and maintained advantages. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018 , 56, 1545–1551 相似文献
45.
The present article describes a working or combined calibration curve in laser-induced breakdown spectroscopic analysis, which is the cumulative result of the calibration curves obtained from neutral and singly ionized atomic emission spectral lines. This working calibration curve reduces the effect of change in matrix between different zone soils and certified soil samples because it includes both the species' (neutral and singly ionized) concentration of the element of interest. The limit of detection using a working calibration curve is found better as compared to its constituent calibration curves (i.e., individual calibration curves). The quantitative results obtained using the working calibration curve is in better agreement with the result of inductively coupled plasma–atomic emission spectroscopy as compared to the result obtained using its constituent calibration curves. 相似文献
46.
47.
I. K. Varma Manjeet S. Choudhary B. S. Rao Sangita D. S. Varma 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(6-7):793-800
Abstract Curing of 4,4′-bismaleimido-diphenyl methane-4,4′ -diaminodi-phenyl methane (1:0.3 molar ratios) (BM-A) was carried out in the presence of vinyl ester-styrene resin. The BM-A could be cured at lower temperatures. The char yields of the cured resins depended on the percentage of bismaleimide-amine in the blend. 相似文献
48.
Mechanical properties of copolymers of 2-hydroxyethyl methacrylate with methyl methacrylate, ethyl methacrylate, and n-butyl methacrylate have been investigated using an Instron tensile tester. It was observed that the overall mechanical properties decrease as the ester alkyl group of alkyl methacrylate becomes bulkier. Biocompatibility of the copolymers was also investigated by implanting them subcutaneously in rats. 相似文献
49.
Pragati R Sharma Shubham Pandey Vineet K Soni Ganpat Choudhary Rakesh K Sharma 《Supramolecular chemistry》2013,25(9):634-644
ABSTRACTThe current study reveals the synthesis of polymer appended Calix[4]amidocrown-5 with specific binding affinity for iodide at ppm-level. The low detection limits are observed via UV-vis and fluorescence spectroscopy. The time-dependent solution and solid-state 127I NMR studies with 18.8 and 19 ppm shifts, indicate a strong sensing nature of resin towards iodide ion. A significant reduction in surface area and pore volume with higher thermostability of resin after iodide uptake indicated iodide inclusion in the amidocrown cavity. The mechanism of iodide sensing may be governed by noncovalent interactions of NH and OH protons present in amidocrown and phenyl ring as observed in terms of emission enhancement in fluorescence spectroscopy. The binding affinity and stoichiometric determinations are determined by Benesi-Hildebrand and Jobs plots, respectively. 相似文献
50.
Navjeet Kaur Pooja Grewal Pranshu Bhardwaj Meenu Devi Neha Ahlawat Yamini Verma 《合成通讯》2013,43(22):3058-3100
The heterocyclic chemistry field has been revolutionized using transition metal catalyst in recent years. Various research groups have focused on the development of general protocols to achieve better functional group compatibilities and greater levels of molecular complexity under mild reaction conditions using easily available starting substrates. These methods afford many advantages as compared to alternative pathways involved in the synthesis of heterocyclic compounds. In this review article, we have concentrated on the synthesis of nitrogen-containing five-membered heterocylces in the presence of silver catalyst. 相似文献