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A highly sensitive extractive spectrophotometric method for the determination of U(VI) using octadecyldithiocarbamate (ODDTC) has been developed. The efficiency of ODDTC as a chelating agent is compared with that of hexadecyl, tetradecyl and dodecyl dithiocarbamates. U(VI) reacts with these dithiocarbamates in ethanol to form reddish-brown water-insoluble chelates capable of being extracted into CHCl3. The molar absorptivities range from 1.16·10 to 4.91·104l·mol–1·cm–1, the highest value being found for ODDTC. Suitable conditions for the extraction and the effect of foreign ions were investigated. The method can be used for the determination of trace amounts of U(VI) in water and sand. The results are comparable to ICP-AES method. 相似文献
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Subbaiyan NK Hill JP Ariga K Fukuzumi S D'Souza F 《Chemical communications (Cambridge, England)》2011,47(21):6003-6005
A novel approach for improving photocurrent in a supramolecular solar cell, composed of zinc porphyrin-oxoporphyrinogen (ZnP-OxP) surface-modified TiO(2), by redox tuning through fluoride anion binding to the redox active host, OxP is demonstrated. 相似文献
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The channelling of 3 MeV protons in the 〈110〉 direction of silicon has been simulated using Vineyard model taking into account
thermally vibrating nuclei and energy loss due to ion-electron interactions. A beam made up of constant energy particles but
with spatial divergence has been simulated for the purpose. The values of the minimum scattering yield and half width of the
channelling dip are shown to be depth sensitive and agree well with the measured values. The dependence of yield on the angle
of incidence has been found to give information of all three types of channelling. The critical angles for the three types
of channelling and wavelength of planar oscillations are consistent with the previous calculations. 相似文献
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Hill JP Subbaiyan NK D'Souza F Xie Y Sahu S Sanchez-Ballester NM Richards GJ Mori T Ariga K 《Chemical communications (Cambridge, England)》2012,48(33):3951-3953
Tetrapyrazinoporphyrazine substituted at its periphery with eight antioxidant 3,5-di-t-butyl-4-hydroxyphenyl groups behaves as a turn-on fluorescent sensor for fluoride anions. Conversely, the precursor antioxidant-substituted 1,2-phthalonitrile was found to act in turn-off mode suggesting that the origin of the phenomenon lies at the phenolate-substituted 1,4-pyrazinyl moiety. 相似文献
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P. Subbaiyan Vijayanand Yong Wang Shigeo Satokawa Shigeru Kato 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(8):913-921
A new methacrylic monomer, 4‐nitro‐3‐methylphenyl methacrylate (NMPM) was prepared by reacting 4‐nitro‐3‐methyl phenol dissolved in methyl ethyl ketone (MEK) in the presence of triethylamine as a catalyst. Copolymerization of NMPM with methyl methacrylate (MMA) has been carried out in methyl ethyl ketone (MEK) by free radical solution polymerization at 70±1°C utilizing benzoyl peroxide (BPO) as initiator. Poly (NMPM‐co‐MMA) copolymers were characterized by FT‐IR, 1H‐NMR and 13C‐NMR spectroscopy. The molecular weights (Mw and Mn) and polydispersity indices (Mw/Mn) of the polymers were determined using a gel permeation chromatograph. The glass transition temperatures (Tg) of the copolymers were determined by a differential scanning calorimeter, showing that Tg increases with MMA content in the copolymer. Thermogravimetric analysis of the polymers, performed under nitrogen, shows that the stability of the copolymer increases with an increase in NMPM content. The solubility of the polymers was tested in various polar and non‐polar solvents. Copolymer compositions were determined by 1H‐NMR spectroscopy by comparing the integral peak heights of well separated aromatic and aliphatic proton peaks. The monomer reactivity ratios were determined by the Fineman‐Ross (r1 =7.090:r2=0.854), Kelen‐Tudos (r1=7.693: r2=0.852) and extended Kelen‐Tudos methods (r1=7.550: r2= 0.856). 相似文献
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A Gurtu P K Malhotra I S Mittra P M Sood SC Gupta VK Gupta GL Kaul LK Mangotra Y Prakash NK Rao ML Sharma 《Pramana》1974,3(5):311-322
This is a continuation of our earlier investigation (Gurtuet al 1974Phys. Lett. 50 B 391) on multiparticle production in proton-nucleus collisions based on an exposure of emulsion stack to 200 GeV/c beam at the NAL. It is found that the ratioR em = 〈n s〉/〈n ch〉, where 〈n ch〉 is the charged particle multiplicity in pp-collisions, increases slowly from about 1 at 10 GeV/c to 1·6 at 68 GeV/c and attains a constant value of 1·71 ± 0·04 in the region 200 to 8000 GeV/c. Furthermore,R em = 1·71 implies an effectiveA-dependence ofR A =A 0.18,i.e., a very weak dependence. Predictions ofR em on various models are discussed and compared with the emulsion data. Data seem to favour models of hadron-nucleon collisions in which production of particles takes place through adouble step mechanism,e.g., diffractive excitation, hydrodynamical and energy flux cascade as opposed to models which envisage instantaneous production. 相似文献
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D'Souza F Chitta R Sandanayaka AS Subbaiyan NK D'Souza L Araki Y Ito O 《Journal of the American Chemical Society》2007,129(51):15865-15871
Photoinduced electron transfer in a self-assembled single-wall carbon nanotube (SWNT)-fullerene(C60) hybrid with SWNT acting as an electron donor and fullerene as an electron acceptor has been successfully demonstrated. Toward this, first, SWNTs were noncovalently functionalized using alkyl ammonium functionalized pyrene (Pyr-NH3+) to form SWNT/Pyr-NH3+ hybrids. The alkyl ammonium entity of SWNT/Pyr-NH3+ hybrids was further utilized to complex with benzo-18-crown-6 functionalized fullerene, crown-C60, via ammonium-crown ether interactions to yield SWNT/Pyr-NH3+/crown-C60 nanohybrids. The nanohybrids were isolated and characterized by TEM, UV-visible-near IR, and electrochemical methods. Free-energy calculations suggested possibility of electron transfer from the carbon nanotube to the singlet excited fullerene in the SWNT/Pyr-NH3+/crown-C60 nanohybrids. Accordingly, steady-state and time-resolved fluorescence studies revealed efficient quenching of the singlet excited-state of C60 in the nanohybrids. Further studies involving nanosecond transient absorption studies confirmed electron transfer to be the quenching mechanism, in which the electron-transfer product, fullerene anion radical, was possible to spectrally characterize. The rates of charge separation, kCS, and charge recombination, kCR, were found to be 3.46 x 10(9) and 1.04 x 10(7) s-1, respectively. The calculated lifetime of the radical ion-pair was found to be over 100 ns, suggesting charge stabilization in the novel supramolecular nanohybrids. The present nanohybrids were further utilized to reduce hexyl-viologen dication (HV2+) and a sacrificial electron donor, 1-benzyl-1,4-dihydronicotinamide, in an electron-pooling experiment, offering additional proof for the occurrence of photoinduced charge-separation and potential utilization of these materials in light-energy harvesting applications. 相似文献