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401.
Abad JM Revenga-Parra M García T Gamero M Lorenzo E Pariente F 《Physical chemistry chemical physics : PCCP》2011,13(13):5668-5678
A study on optical and electrochemical properties resulting upon interaction of Schiff base ligands with gold nanoparticles is presented. The measurements of the optical absorption and fluorescence properties have provided important information about structure-properties dependence. We show that in function of the isomer structure and its attachment orientation with respect to the metal nanoparticle, their optical properties can be modulated. Nanoparticle assemblies mediated by 3,4-DHS were also obtained based on a control of the interparticle interactions and their electrocatalytic activity toward NADH oxidation was investigated. 相似文献
402.
Prof. Avelino Corma Javier Navas Tania Ródenas Dr. María J. Sabater 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(51):17464-17471
Palladium on magnesium oxide is able to allow a one‐pot reaction to synthesize thioethers from thiols and aldehydes formed in situ from the respective alcohol by means of a borrowing hydrogen method. The reaction is initiated by dehydrogenation of the alcohol to give a palladium hydride intermediate and an aldehyde. The latter reacts with a thiol involving most probably the intermediacy of a thionium ion RCH?S+R, which can be reduced in situ by the metal hydride to afford thioethers. 相似文献
403.
Sangeetha Chenampulli G. Unnikrishnan A. Sujith Sabu Thomas Tania Francis 《Cellulose (London, England)》2013,20(1):429-438
Pandanus utilis a plant abundant throughout Kerala, India has been used as a source to isolate nano-particles. The fibres were extracted from Pandanus plant by biological natural retting. Extracted fibres were dried, ground and treated with 5 % NaOH followed by bleaching using 5 wt % hypochlorite solution. Bleached cellulose was hydrolysed using sulphuric acid. After centrifugation, suspension was freeze dried. Effect of Acid concentration, temperature and time of hydrolysis on the isolation of cellulose nanoparticles was studied. FESEM images of cellulose showed the presence of spherical nano-particles. Dynamic light scattering revealed homogeneous dispersion of nano-particles. Degree of polymerisation of cellulose was determined viscometrically using cupriethylene-diamine as solvent. Removal of lignin and hemicelluloses was confirmed from FTIR spectra. X-Ray diffractograms of powdered fibre, bleached cellulose and nano-cellulose were compared. Using peak height method and peak de-convolution method, crystallinity indices were determined. Using Scherrer equation crystallite size was calculated and it further confirmed that particles are of nanometre size. 相似文献
404.
Viktoria Lachkova Sabi Varbanov Gerhard Hägele Helmut Keck Tania Tosheva 《Phosphorus, sulfur, and silicon and the related elements》2013,188(5):1303-1313
A group of hitherto unknown 1-aryl-3,3-bis(dimethyl-phosphinoylmethyl)-, 1-benzyl-3,3-bis(dimethyl-phosphinoylmethyl)- and 1-cyclohexyl-3,3-bis(dimethyl-phosphinoylmethyl) ureas and thioureas 1-10 have been synthesized, characterized, and are reported in this article. The compounds were prepared via reaction of corresponding isocyanates or isothiocyanates with the secondary phosporus-containing amine: bis(dimethyl-phosphinoylmethyl)-amine. The composition of the novel compounds was proved by elemental analysis, corresponding structures were confirmed by IR, 1 H-, 31 P-, 31 P{ 1 H}-NMR spectroscopy and by mass spectrometry. 相似文献
405.
406.
Tania Jahanbin Mansor Hashim Khamirul Amin Mantori 《Journal of magnetism and magnetic materials》2010,322(18):2684-580
The magnetic and physical properties of ferrites are very sensitive to microstructure, which in turn critically depends on the manufacturing process. In this study, nickel zinc ferrite powder with composition Ni0.8Zn0.2Fe2O4 has been prepared via conventional ceramic processing and co-precipitation methods. The toroidal and pellet form samples were sintered at various temperatures such as 1100, 1200 and 1300 °C. The microstructure, magnetic and dielectric properties of both samples were studied. The X-ray diffraction patterns confirm the formation of single-phase cubic spinel structure for the co-precipitation technique after sintering. The microstructure studies of Ni0.8Zn0.2Fe2O4 show the grain size increases and the porosity decreases with temperature for both methods. The controlled permeability with small loss and wide operational frequency range are found in the co-precipitation samples. Dielectric constants decrease with increase of frequency and increase with sintering temperature in both methods. Consequently, the homogenous microstructure with the low-loss high-performance of nickel zinc ferrite has been discovered by means of co-precipitation method. 相似文献
407.
The synthesis of aromatic copolyamidethioethers by reaction of dichlorobenzanilides with Na2S has been studied. The reactivity of chlorine atoms is strongly dependent on the nature of the substituent in para position. It is related to the 13C NMR shifts of the relative carbons-the more deshielded, the more reactive-and hence to charge densities, agreing with aromatic nucleophilic substitution mechanisms. The results are discussed in relation to the various mechanisms which have been put forward for the reaction of Na2S with 1, 4-dichlorobenzene (PPS synthesis). 相似文献
408.
409.
The β — 1.3/1.6 glucan schizophyllan is known to suppress tumor growth. Two different schizophyllan samples have been characterized by static and dynamic light scattering in dilute solution of 0.01M NaOH and dimethyl sulfoxide (DMSO). A thermoreversible, optically transparent gel of schizophyllan was obtained on addition of sorbitol to aqueous solution, and the gelation process was followed by low amplitude oscillatory shear and dynamic light scattering (DLS). Power law behavior of storage modulus G'(ω) and loss modulus G”(ω) with the exponent n=0.5 was found at the gel temperature. In the same temperature range intensity time correlation functions (TCF) were measured and the electric field TCFs were calculated, taking into account the heterodyne contributions. The occurrence of two motions gave evidence for inhomogeneities in the gel. The results of the slow motion from DLS agreed surprisingly well with those, estimated by oscillatory rheology. The viscoelastic properties and the influence of sorbitol and schizophyllan concentrations were investigated regarding the pharmaceutical application in cancer therapy. 相似文献