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91.
Summary Peroxodisulfate ion readily oxidises CoII-YOH [YOH =N(2-hydroxyethyl)ethylenediaminetriacetate] with the formation of an intermediate complex. The kinetics of the electron-transfer step follow the rate law: Rate = 2kHKH[H+][S2O8]2-[CoII-YOH]/(1 + KH[H+]) where [S2O8]2– is the total peroxodisulfate concentration, kH is the rate constant for the electron-transfer process, and KH is the pre-equilibrium protonation constant. Activation parameters have been evaluated. The intermediate, which was identified spectrophotometrically, slowly rearranges to the quinquedentate species Co(YOH)(H2O). The rate of this rearangement has also been measured. 相似文献
92.
Der‐Jang Liaw Kun‐Li Wang En‐Tang Kang Sidharam Pundlik Pujari Min‐Hung Chen Ying‐Chi Huang Bo‐Cheng Tao Kueir‐Rarn Lee Juin‐Yih Lai 《Journal of polymer science. Part A, Polymer chemistry》2009,47(4):991-1002
A new diiodo monomer containing heterocyclic pyridine and carbazole groups was synthesized via Chichibabin reaction and used in the preparation of a conjugated polymer via Suzuki coupling approach. The conjugated polymer was highly soluble in common organic solvents such as NMP, THF, dichloromethane, chloroform, toluene, xylene, and benzene at room temperature. The polymer had high glass transition temperature at 191 °C and Td10 at 434 °C in nitrogen atmosphere. The pristine polymer exhibited the UV–vis maximum absorption at 355 nm and shifted to 420 nm after protonation. The emission of the polymer in THF solution changed from the blue region with maximum peak at 400 nm to the yellow region with maximum peak at 540 nm after protonated by HCl, and the intensity of emission depended on the concentration of acid. The polymer also showed electrochromic behavior under applied voltage. The emission color of the polymer film changed from blue (435 nm) to yellow (570 nm) when 2.5 V bias voltage was applied. The polymer also exhibited write‐once and read‐many‐times (WORM) polymer memory effect with tristable states. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 991–1002, 2009 相似文献
93.
H. S. Sodaye P. K. Pujari A. Goswami S. B. Manohar 《Radiation Physics and Chemistry》2000,58(5-6):567-570
We have measured the S-parameter and life-time as a function of temperature from 15 to 300 K in acid Nafion-117. In addition, high temperature measurements from 300 to 550 K have been carried out in acid as well as Cs neutralised Nafion membrane. The results are discussed. 相似文献
94.
This paper presents an integrated inventory distribution optimization model that simultaneously incorporates the issues of location, production, inventory, and transportation within a supply chain. The objective is to determine the optimal number and size of shipments under varying but commonly practiced production and shipping scenarios. A continuous approximation procedure is proposed to determine the optimal number and size of shipments. Three production and shipping scenarios are investigated and closed form expressions for the optimal number of shipments for each scenario are obtained. A numerical example is presented to demonstrate the usefulness of the model. 相似文献
95.
H. Naik T. Datta S. P. Dange R. Guin P. K. Pujari S. M. Sahakundu S. Prakash 《Zeitschrift für Physik A Hadrons and Nuclei》1992,342(1):95-100
Independent isomeric yield ratios of132I were radiochemically determined in alpha particle induced fission of238U in the energy range 25–44 MeV. Fission fragment angular momenta were deduced from the measured isomeric yield ratios using spin dependent statistical model analysis. It was seen that angular momentum of132I increases with increase of excitation energy and angular momentum of the fissioning nucleus. Comparison of the present data on132I in238U(α,f) with the literature data for the same product in238U(p, f) and238U(γ, f) at various excitation energies show that fragment angular momentum strongly depends on the input angular momentum in the range of excitation energy considered. Experimental fragment angular momentum at all excitation energies were seen to be in agreement with the theoretical values calculated based on thermal equilibration of the various collective rotational degrees after considering the occurence of multichance fission. Thus, strong effect of input angular momentum as well as the statistical equilibration among the various collective rotational degrees of freedom in medium energy fission is corroborated. 相似文献
96.
97.
98.
2, 6, 12, and 20 electron quantum dots have been studied using coupled cluster at singles and doubles level and extensive multireference coupled cluster (MRCC) method. A Fock-space version of MRCC (FSMRCC) containing single hole-particle excited determinants has been used to calculate low-lying excited states of the above system. The ionization potential and electron affinity are also calculated. The effect of correlation energy on excitation energy and charge density is shown by calculating them at the high density region (low value of density parameter rs) and at the low density region (high value of density parameter rs). 相似文献
99.
Pujari NS Inamdar SR Ambekar JD Kulkarni BD Ponrathnam S 《Chemistry (Weinheim an der Bergstrasse, Germany)》2007,13(20):5862-5872
A series of copolymers of 2-hydroxyethyl methacrylate (HEMA)/glycidyl methacrylate (GMA) and ethylene dimethacrylate (EGDM) were synthesized by frontal polymerization (FP). This study was conducted to investigate the effect of crosslink density, type and concentration of initiator, the use of a complex initiator system, porogen, and diluent on the most relevant parameters of FP, such as sustainability of the front, temperature profile, front velocity, and yield. The products were also characterized for intruded pore volume, pore-size distribution, epoxy-functionality number, and surface morphology. Higher crosslink densities (CLDs) and initiator concentration produced higher front velocities, whereas no trend in front temperature was noted. A complex initiation system was effective in stabilizing and increasing the polymerization yield. Relative to suspension polymerization (SP), FP products synthesized without a solvent were microporous, whereas micro-to-macroporous products were obtained in the presence of a solvent (for HEMA-EGDM polymers). We also present, explain, and discuss the exotic patterns observed under a microscope. We observed two basic types of spatial patterns, namely, planar and nonplanar patterns. The type of planar pattern observed under scanning electron microscopy (SEM) has a spatial impulse that appears as a loop followed by regular periodic motion in the radial and axial directions. This behavior gives rise to a repeating pattern that is a few microns thick. Also, nonplanar patterns, namely, layered concentric rings and winding staircase patterns, were observed under SEM. 相似文献
100.
R. Acharya K. B. Dasari D. Chandra Shekhar T. P. Chaturvedi P. K. Pujari 《Journal of Radioanalytical and Nuclear Chemistry》2014,302(3):1333-1337
A digital gamma-ray spectrometer with loss-free counting system was used for real time correction for dead time (DT) due to pulse processing in the electronics. This spectrometer was used for radioactive assay of samples having constant as well as varying DT conditions. The system was tested by measuring activity of short and medium lived nuclides namely 28Al, 52V and 128I in the DT ranges of 80–2 %. Using this spectrometer and neutron activation analysis (NAA), concentrations of Al, V, Ti, Ca, Dy and Mn were determined in some samples and reference materials. 相似文献