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排序方式: 共有201条查询结果,搜索用时 15 毫秒
1.
Bala Ritu Das Debabrata Karanveer Naskar Nabanita Lahiri Susanta 《Journal of Radioanalytical and Nuclear Chemistry》2022,331(6):2561-2572
Journal of Radioanalytical and Nuclear Chemistry - Natural radionuclide levels are studied in alluvial sediments upto the depth of 900 cm. Eighteen profiles are selected from agricultural... 相似文献
2.
Arijit Ghorai Arun Kumar Mandal Susanta Banerjee 《Journal of polymer science. Part A, Polymer chemistry》2020,58(2):263-279
Sulfonated polytriazoles have drawn a great attention as high performance polymers and their good film forming ability. In the present study, a phosphorus containing new diazide monomer namely, bis-[4-(4′-aminophenoxy)phenyl]phenylphosphine was synthesized and accordingly, a series of phosphorus containing sulfonated polytriazoles (PTPBSH-XX) was synthesized by reacting equimolar amount of this diazide monomer (PAZ) in combination with another sulfonated diazide monomer (DSAZ) and a terminal bis-alkyne (BPALK) by the Cu (I) catalyzed azide–alkyne click polymerization. The polymers were characterized by nuclear magnetic resonance (1H, 13C, 31P NMR) and Fourier transform infrared spectroscopic techniques. The sulfonic acid content of the copolymers also determined from the different integral values obtained from the 1H NMR signals. The small-angle X-ray scattering results unfolded the well-separated dispersion of the hydrophilic and hydrophobic domains of the polymers. As a whole, the copolymer membranes displayed sufficient thermal, mechanical, and oxidative stabilities high with high proton conductivity and low water uptake that are essential for proton exchange membrane applications. The copolymers exhibited oxidative stability in the range of 15–24 h and had proton conductivity values were found as high as 38–110 mS cm−1 at 80 °C in completely hydrated condition. Among the all copolytriazoles, PTPBSH-90 (BPALK:DSAZ:PAZ = 100:90:10) having IECW = 2.44 mequiv g−1, showed proton conductivity as high as 119 mS cm−1 at 90 °C with an activation energy of 10.40 kJ mol−1 for the proton conduction. © 2020 Wiley Periodicals, Inc. J. Polym. Sci. 2020 , 58, 263–279 相似文献
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We present an analysis of structural, electronic, and mechanical properties of cubic titanium dioxide(TiO_2) using an all electron orthogonalzed linear combinations of atomic orbitals(OLCAO) basis set under the framework of density functional theory(DFT). The structural property, especially the lattice constant a, and the electronic properties such as the band diagram and density of states(DOS) are studied and analyzed. The mechanical properties such as bulk moduli, shear moduli, Young's Moduli, and Poison's ratio are also investigated thoroughly. The calculations are carried out on shear moduli and anisotropy factor for cubic TiO_2. The Vickers hardness is also tested for fluorite and pyrite cubic-structured TiO_2. Furthermore, the results are compared with the previous theoretical and experimental results. It is found that DFTbased simulation produces results which are approximation to experimental results, whereas the calculated elastic constants are better than the previous theoretical and experimental values. 相似文献
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Pradhan Susanta Kumar Ambade Balram 《Journal of Radioanalytical and Nuclear Chemistry》2021,329(1):115-125
Journal of Radioanalytical and Nuclear Chemistry - Neutral complexes of thorium and lanthanides with 2,3-dihydroxynaphthalene and anionic complexes of uranium with the same chelating agent in... 相似文献
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A new AB type of monomer 4′-fluoro-3,5-dimethyl-3′-trifluoromethyl-biphenyl-4-ol has been synthesized that leads to a new poly(arylene ether) by self polycondensation reaction. The monomer and the polymer have been well characterized by elemental analyses, FT-IR and NMR spectroscopy. Both FT-IR and NMR spectra of the polymers did not show any terminal phenoxy group indicating high conversion. The polymer showed glass transition at 278°C and very good thermal stability in synthetic air. GPC results indicate high molar mass development; Mw = 53200 and MWD = 2.29. 相似文献
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An aqueous biphasic extraction system was designed using different molecular weights of polyethylene glycol and concentrated
salt solutions of sodium sulphate to separate the heavy metals, Hg, Tl and Pb from Li irradiated Au matrix. All the four elements
could be separated from one another by this extraction process by simply optimizing the salt rich phase, the pH of the salt
rich phase and the molecular weight of the polymer rich phase. 相似文献
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Low dielectric constant apolar aprotic solvents, although employed on a limited scale for studying proton transfer reactions as compared with commonly used polar protic or dipolar aprotic ones, offer some particular advantages, namely, specific solute–solvent interactions are virtually eliminated and proton transfer occurs directly in an apolar aprotic solvent. An intriguing feature of these reactions is their general acid‐catalyzed/base‐catalyzed kinetics with a time scale over microseconds to minutes. In fact, the true or intrinsic relative strengths of acids/bases when measured in such solvents come to the fore much more clearly than those obtained in other classes of solvents. Recently, a review documenting the post‐1980 developments relating to proton transfer reactions in apolar aprotic solvents has been published. The present article is a commentary of the pre‐1980 developments in this area since the 1920s Brønsted–Lowry's “proton cult” of acid–base theory. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
10.
The uptake behavior of long-lived radionuclides such as 134Cs (2.06 years), 137Cs (30 years) or 133Ba (10.54 years) on calcium alginate (CA) beads have been investigated. The CA beads are able to remove 133Ba (92%) at pH 7 after 90 min of exposure from the binary mixture of two. The separation method of short-lived daughter 137Ba (2.55 min) from its long-lived parent 137Cs (30 years) using this CA beads have also been developed. 相似文献