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排序方式: 共有119条查询结果,搜索用时 31 毫秒
41.
42.
Zhang J Adhikary A King KM Krause JA Guan H 《Dalton transactions (Cambridge, England : 2003)》2012,41(26):7959-7968
Pincer complexes of the type [2,6-(R(2)PO)(2)C(6)H(3)]NiSC(6)H(4)Z (R = Ph and i-Pr; Z = p-OCH(3), p-CH(3), H, p-Cl, and p-CF(3)) have been synthesized from [2,6-(R(2)PO)(2)C(6)H(3)]NiCl and sodium arylthiolate. X-ray structure determinations of these thiolate complexes have shown a somewhat constant Ni-S bond length (approx. 2.20 ?) but an almost unpredictable orientation of the thiolate ligand. Equilibrium constants for various thiolate exchange (between a nickel thiolate complex and a free thiol, or between two different nickel thiolate complexes) reactions have been measured. Evidently, the thiolate ligand with an electron-withdrawing substituent prefers to bond with "[2,6-(Ph(2)PO)(2)C(6)H(3)]Ni" rather than "[2,6-(i-Pr(2)PO)(2)C(6)H(3)]Ni", and bonds least favourably with hydrogen. The reactions of the thiolate complexes with halogenated compounds such as PhCH(2)Br, CH(3)I, CCl(4), and Ph(3)CCl have been examined and several mechanistic pathways have been explored. 相似文献
43.
Vyas PV Ray P Adhikary SK Shah BG Rangarajan R 《Journal of colloid and interface science》2003,257(1):127-134
Heterogeneous ion-exchange membranes (both cationic and anionic types) have been synthesized by solution casting techniques using polyvinyl chloride (PVC) as binder and ion-exchange resin (-300+400 mesh). The binder:resin ratio varied from 60:40 to 30:70. The transport behavior of the membranes has been evaluated chronopotentiometrically in sodium chloride (NaCl) solutions of different concentrations. The different parameters E(0) (potential drop across the membrane at the instant of application of current I), E(max) (maximum potential drop across the membrane after the application of current I), DeltaE (magnitude of the potential jump across the membrane at transition time tau), Itau(1/2), tau, etc., have been evaluated. The isoconductance points were determined and based on the microheterogeneous model proposed by Zabolotsky and Nikonenko (J. Membrane Sci. 79 (1993) 181) the distribution factors beta has been evaluated for both types of ion exchange membranes. The electroconductivity of the joint gel (kappa ) and pure gel phases (kappa ' ) has been determined. At any particular solution concentration the transport number as well as the permselectivity of membranes increases with increased resin content of the membrane. The microheterogeneity factor beta exhibits synchronization among the each set of four different membranes for both the cationic and anionic type. 相似文献
44.
SK. Musharaf Ali 《Molecular physics》2013,111(4):387-393
We propose a simple hybrid model for the shear viscosity of isotopic fluid mixtures by coupling the contribution of the Stokes–Einstein relation with the existing linear model of Roults's law for the shear viscosity. The calculated values of shear viscosity using this simple hybrid model are found to be in excellent agreement with the molecular dynamics (MD) simulation results. The calculated value of the shear viscosity obtained from the theoretical model as well as the MD simulation increases with increasing mass ratio. 相似文献
45.
Flexible hybrid eu3+ doped P(VDF‐HFP) nanocomposite film possess hypersensitive electronic transitions and piezoelectric throughput 下载免费PDF全文
Prakriti Adhikary Samiran Garain Shanker Ram Dipankar Mandal 《Journal of Polymer Science.Polymer Physics》2016,54(22):2335-2345
A novel red light‐emitter made of Eu3+ doped self‐poled electroactive poly(vinylidene fluoride–hexafluoropropylene) [P(VDF‐HFP)] hybrid nanocomposite film possesses piezoelectric throughput that is suitable for flexible piezoelectric nanogenerator (PNG) fabrication. We observed that PNG is enabled to generate an open‐circuit voltage of 5 V and 0.35 μA of short‐circuit current under an applied pressure amplitude of ~10.4 kPa. By simple mechanical energy scavenging, PNG demonstrates an ability to light more than ten blue commercial light emitting diodes instantly, without using an energy‐storage device. Additionally, it successfully charges up capacitors by simple repeating finger touch motion, which indicates its potency as an efficient energy harvesting power source. The high performance of PNG is due to well‐coated Eu3+ with P(VDF‐HFP) in a hybrid nanocomposite so it displays improved dielectric permittivity and energy storage capacity. This flexible composite film also possesses a hypersensitive electronic transition as it responds by an intense red light‐emission confirmed by the CIE 1931 chart. This enables applications in piezo‐photonics as a high‐performance, energy‐saving, flexible solid‐state red light emitter. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 2335–2345. 相似文献
46.
The effect of Nd3+ concentration on the CW and Q-switched laser performances at 1064 nm from Nd: YVO4 has been studied under diode laser pumping in identical laser configuration. The Nd3+ concentrations used were 1, 2 and 3 at.% in YVO4 crystals. Under the CW operations we have compared the thermal lensing effect, slope efficiencies and also the beam quality
at the fourth-order degeneracy configuration. Q-switching was done with the help of an acousto-optic modulator and we have
compared the pulses obtained from Nd: YVO4 laser with different doping concentration. It was found that the 1 at.%-doped crystal is the best, offering highest optical-to-optical
conversion efficiency (55%), lowest fractional heat load (24%), highest pulse energy (80 μJ) and shortest pulse width (20 ns). It was also found that there was not much difference in performances for 2 and 3 at.%-doped
crystals both in CW and Q-switched configurations. 相似文献
47.
Clemens von Sonntag Eberhard Bothe Piotr Ulanski Amitava Adhikary 《Radiation Physics and Chemistry》1999,55(5-6):599-603
Free-radical transfer in polymers have been studied by pulse radiolysis and product analysis with the water-soluble polymers poly(vinyl alcohol), poly(acrylic acid), poly(methacrylic acid), polynucleotides and DNA. When OH radicals react with polymers the lifetime of the polymer radical thus created strongly depends on the number of radicals per polymer chain. Moreover, in negatively charged polymers the increased stiffness at high pH results in a remarkable increase of the lifetime of the radicals with respect to recombination. This allows a number of radical transfer reactions to occur (e.g. intramolecular H-transfer, β-fragmentation, depolymerization, reactions with additives). 相似文献
48.
S B Roy Shailendra Kumar A K Pradhan P Chaddah Ram Prasad N C Soni Kalyan Adhikary 《Pramana》1993,41(1):51-60
We present measurements of harmonic generation in the magnetization of sintered pellets of YBa2Cu3O7 and Bi1.7Pb0.3Sr2Ca2Cu3O10 as a function of DC field. The DC field is applied in the field-cooled mode. Measurements are made at 77 K for various values
of the AC field amplitude. A comparison is made with calculations done within the critical state model. 相似文献
49.
Chandan Adhikary Rajesh Bera Buddhadeb Dutta Sreyashi Jana Gabriele Bocelli Andrea Cantoni Siddhartha Chaudhuri Subratanath Koner 《Polyhedron》2008
Three copper(II) Schiff-base complexes, [Cu(L1)(H2O)](ClO4) (1), [Cu(L2)] (2) and [Cu(L3)] (3) have been synthesized and characterized [where HL1 = 1-(N-ortho-hydroxy-acetophenimine)-2-methyl-pyridine], H2L2 = N,N′-(2-hydroxy-propane-1,3-diyl)-bis-salicylideneimine and H2L3 = N,N′-(2,2-dimethyl-propane-1,3-diyl)-bis-salicylideneimine]. The structure of complex 1 has been determined by single crystal X-ray diffraction analysis. In complex 1, the copper(II) ion is coordinated to one oxygen atom and two nitrogen atoms of the tridentate Schiff-base ligand, HL1. The fourth coordination site of the central metal ion is occupied by the oxygen atom from a water molecule. All the complexes exhibit high catalytic activity in the oxidation reactions of a variety of olefins with tert-butyl-hydroperoxide in acetonitrile. The catalytic efficacy of the copper(II) complexes towards olefin oxidation reactions has been studied in different solvent media. 相似文献
50.
Visible light driven amide synthesis in water at room temperature from Thioacid and amine using CdS nanoparticles as heterogeneous Photocatalyst 下载免费PDF全文
Sudipto Das Shounak Ray Abhisek Brata Ghosh Partha Kumar Samanta Suvendu Samanta Bibhutosh Adhikary Papu Biswas 《应用有机金属化学》2018,32(3)
Highly efficient photocatalytic thioacid mediated amide synthesis at room temperature using CdS nanoparticles as photocatalyst was observed under a household 30 W CFL in water. The operationally mild reaction was tolerant to a number of functional group substitutions on amine and could be scaled up to gram. This heterogeneous photocatalyst was extremely stable and could easily be recovered by simple centrifugation for at least six recycling reactions without any significant loss of catalytic performance. The possible reaction mechanism for the photocatalytic thioacid mediated amide synthesis over the CdS semiconductor has also been proposed on the basis of experimental observations. 相似文献