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51.
Prakash S. Sane Bhausaheb V. Tawade Indravadan Parmar Savita Kumari Samadhan Nagane Prakash P. Wadgaonkar 《Journal of polymer science. Part A, Polymer chemistry》2013,51(9):2091-2103
Two new initiators, namely, 4‐(4‐(2‐(4‐(allyloxy) phenyl)‐5‐hydroxypentane 2‐yl) phenoxy)benzaldehyde and 4‐(4‐(allyloxy) phenyl)‐4‐(4‐(4‐formylphenoxy) phenyl) pentyl 2‐bromo‐2‐methyl propanoate containing “clickable” hetero‐functionalities namely aldehyde and allyloxy were synthesized starting from commercially available 4,4′‐bis(4‐hydroxyphenyl) pentanoic acid. These initiators were utilized, respectively, for ring opening polymerization of ε‐caprolactone and atom transfer radical polymerization of methyl methacrylate. Well‐defined α‐aldehyde, α′‐allyloxy heterobifunctionalized poly(ε‐caprolactones) (Mn,GPC: 5900–29,000, PDI: 1.26–1.43) and poly(methyl methacrylate)s (Mn,GPC: 5300–28800, PDI: 1.19–1.25) were synthesized. The kinetic study of methyl methacrylate polymerization demonstrated controlled polymerization behavior. The presence of aldehyde and allyloxy functionality on polymers was confirmed by 1H NMR spectroscopy. Aldehyde‐aminooxy and thiol‐ene metal‐free double click strategy was used to demonstrate reactivity of functional groups on polymers. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013 相似文献
52.
Densities (ρ), ultrasonic speeds (u), and excess molar volumes (VmEV_{\mathrm{m}}^{\mathrm{E}}) of binary mixtures of some aromatic ketones in acrylonitrile have been measured over the entire range of composition at
308.15 K. From these experimental results, parameters such as the isentropic compressibilities K
S
, interaction parameter χ
12, Flory parameters, A
i
coefficients, standard deviations σ(Y
E), and molar sound velocities R
m have been estimated. The excess functions were fitted to Redlich-Kister type polynomial equations. The experimental ultrasonic
speeds were analyzed in terms of Jacobson’s Free Length Theory (FLT), Schaaff’s Collision Factor Theory (CFT), Nomoto’s relation,
and Van Dael’s ideal mixture relation. The intermolecular Free Length L
f, and available volume V
a, have been calculated from the FLT, CFT, and thermoacoustic approaches for binary systems of acetophenone and propiophenone
in acrylonitrile at 308.15 K. 相似文献
53.
Savita J. Singh 《Tetrahedron letters》2008,49(27):4249-4251
A facile, efficient and chemoselective protocol for O-tert-butoxycarbonylation of various hydroxy compounds has been developed using NaLaTiO4 (layered perovskite) as a novel catalyst. The catalyst showed remarkable activity and reusability affording high yields of the desired products under mild reaction conditions. 相似文献
54.
The complexes of silicon (IV) with Schiff base ligands (L1H and L2H of isatin derivatives) having a sulfur and oxygen donor system were prepared by the reactions in methanol environment. These were isolated and characterized by elemental analysis, molecular weight determinations and conductance measurements. On the basis of electronic, infrared, 1H, 13C and 29Si NMR spectral studies, trigonal bipyramidal geometry was suggested for the resulting complexes. These data support preferential binding of sulfur and oxygen atom to the silicon atom. The disease resistance activities of the ligands and their corresponding complexes were examined successfully in in vitro and in vivo experiments, against pathogenic fungi and bacteria. Results were quite encouraging and these were compared with the standard pesticides Bavistin and Streptomycin. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
55.
The paper describes the availability of combed sliver production system, a part of yarn production plant. The units under study are specialized single purpose machines. Performance analysis of the system is carried out to identify the key factors. The optimum value of ‘r’, where ‘r’ represent the number of repairman to repair the twelve carding machines (r ? 12), is calculated to maximizing the steady state availability of the system. The problem is formulated using probability consideration and supplementary variable technique. Probability considerations at various stages give differential-difference equations, which are solved using Lagrange method to obtain the state probabilities. The numerical analysis carried out helps in increasing the production rate by controlling the factors affecting the system i.e. availability optimization. 相似文献
56.
Several low-melting sugar mixtures (LMMs) were synthesized and used for preparation of 1,4-dihydropyridines with aldehydes, 1,3-dicarbonyl compounds, and a nitrogen source as starting materials. Good yields, low reaction times, recyclability of LMMs, and catalyst-free methodology are some of the highlights of this new protocol. 相似文献
57.
Zinc alpha2-glycoprotein (ZAG) is present at high concentration in human seminal plasma, and considered as soluble homologue of MHC-I. ZAG is a well-known biomarker for prostate and breast carcinomas. We have purified a naturally occurring complex of ZAG with Prolactin inducible protein (PIP), which is also a well-known biomarker for the same. The ZAG-PIP complex has been isolated and purified by simple chromatographic techniques in a reproducible two-step process, using ion exchange and gel-permeation chromatography and subsequently identified by MS. The complex between ZAG and PIP is formed by non-covalent interactions. The purity and molecular mass was determined by SDS-PAGE, which shows the bands corresponding to 40 kDa and 14 kDa, which were also confirmed by MALDI-TOF. Dynamic light scattering (DLS) experiments also showed hydrodynamic radii corresponding to 54, 40 and 14 kDa for ZAG-PIP complex, ZAG and PIP respectively. The concentration dependent aggregation of this complex has also been observed. Fluorescence analysis reveals that complexes have similar binding affinities as native ZAG, for their proposed ligands like arachidonic acid, polyethylene glycol and synthetic peptide. This is the first report on purification and characterization of a naturally occurring complex of ZAG-PIP in human seminal fluid. 相似文献
58.
Maury Suresh Kumar Kumar Dhirendra Kamal Arsala Singh Himanshu Kumar Kumari Savita Singh Sundaram 《Molecular diversity》2021,25(1):131-142
Molecular Diversity - A facile and efficient multicomponent synthesis of benzodiazepine ring in water under ultrasound irradiation is reported first time. The current procedure escapes traditional... 相似文献
59.
Triphenylantimony(V) heteroleptic derivatives containing substituted oximes and morpholine dithiocarbamate of the type Ph3Sb[R(R′)C:NO]2[S2CN(CH2CH2)2O] (where R = ─C6H5, R′ = ─CH3 (I); R = ─C6H4CH3, R′ = ─CH3 (II); R = ─C6H4Cl, R′ = ─CH3 (III); R = ─C6H4Br, R′ = ─CH3 (IV); R = ─C6H4OH, R′ = ─H (V); R(R′)C = CCH2(CH2)3CH2 (VI)) were synthesized by successive substitution reactions of triphenylantimony(V) dibromide with the sodium salt of substituted oximes and morpholine dithiocarbamate in unimolar ratio. All these newly synthesized derivatives were characterized using physicochemical and elemental analyses and tentative structures have been proposed on the basis of infrared, (1H, 13C) NMR and liquid chromatography–mass spectra. Spectral data revealed that the oxime behaves in a monodentate manner whereas morpholine dithiocarbamate behaves in an anisobidentate manner and thus distorted octahedral geometry has been proposed for these derivatives. Nanometric particle size (ca 25 nm) and monoclinic crystal system have been determined using power X‐ray diffraction data of two representative derivatives. Furthermore, these newly synthesized derivatives were screened against two bacteria, Bacillus subtilis (Gram‐positive) and Escherichia coli (Gram‐negative), to evaluate their antibacterial potential. Derivative VI exhibited maximum zone of inhibition (30 mm) against E. coli. Additionally two derivatives (I and II) were tested for their antioxidant potential, with derivative II exhibiting higher antioxidant potential (233 μM g?1). Structure–activity relationships were also investigated. 相似文献
60.
A. K. Narula S. K. Goyal Savita Saini R. P. Chauhan S. K. Chakarvarti 《Indian Journal of Physics》2009,83(8):1171-1175
The diffusion of radon in dwellings is a process determined by the radon concentration gradient across the building material
structure between the radon source and the surrounding air, and can be a significant contributor to indoor radon inflow. Radon
can originate from the deeply buried deposit beneath homes and can migrate to the surface of earth. Radon emanates to the
surfaces mainly by diffusion processes from the point of origin following α-decay of 226Ra in underground soil and building materials used, in the construction of floors, walls, and ceilings. In the present study
radon diffusion through some building materials viz. coarse sand and stone dust of different grain size has been carried out using LR-115 type II solid-state nuclear track detectors
(SSNTDs). The radon diffusion coefficients and diffusion lengths through these building construction materials have been calculated.
The effect of grain size on radon diffusion through these building materials shows the decrease in radon diffusion with decrease
in grain size. 相似文献