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41.
42.
Soumya Chakrabarti 《General Relativity and Gravitation》2017,49(2):24
An analogue of the Oppenheimer–Synder collapsing model is treated analytically, where the matter source is a scalar field with an exponential potential. An exact solution is derived followed by matching to a suitable exterior geometry, and an analysis of the visibility of the singularity. In some situations, the collapse indeed leads to a finite time curvature singularity, which is always hidden from the exterior by an apparent horizon. 相似文献
43.
A new exactly solvable ()-dimensional complex nonlinear wave equation exhibiting rich analytic properties has been introduced. A rogue wave (RW), localized in space–time like Peregrine RW solution, though richer due to the presence of free parameters is discovered. This freedom allows to regulate amplitude and width of the RW as needed. The proposed equation allows also an intriguing topology changing accelerated dark soliton solution in spite of constant coefficients in the equation. 相似文献
44.
45.
Detrimental Ni(0) transfer in Kumada catalyst transfer polycondensation of benzo[2,1‐b:3,4‐b']dithiophene
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Anjan Bedi Julien De Winter Pascal Gerbaux Guy Koeckelberghs 《Journal of polymer science. Part A, Polymer chemistry》2016,54(12):1706-1712
This article deals with the Kumada Catalyst Transfer Polycondensation (KCTP) of 4,7‐dioctylbenzo[2,1‐b:3,4‐b']dithiophene ( BDP‐Oct ) using Ni(II) catalyst or In/cat combination. A combination of MALDI MS, GPC, and 31P NMR spectroscopy is used to reveal the failure of the KCTP of this particular monomer. Intermolecular transfer reactions to monomer appeared to prevent the formation of polymer. This result is remarkable, since isomeric benzo[1,2‐b:4,5‐b']dithiophene polymerizes in a controlled way. The presence of a “non‐aromatic double bond” in annulated monomers is discussed. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 1706–1712 相似文献
46.
47.
Pradep Mathur Anjan K. Bhunia Ch. Srinivasu Shaikh Md. Mobin 《Phosphorus, sulfur, and silicon and the related elements》2013,188(4-5):899-901
Group 16 elements serve as useful bridging and stabilising single atom ligands in mixed-metal carbonyl complexes and impart unusual reactivity on coordinated acetylenic moieties. Reactions of [Fe 3 (CO) 9 (μ 3 -E) 2 ] (E = S, or Se) with mononuclear acetylide complexes, [CpM(CO)_3-x(CCR)] (M = Mo or W, x = 0, R = Ph; M = Fe, x = 1, R = Ph or ferrocenyl) under facile conditions yield complexes featuring acetylide coupling, acetylide-flip and formation of oxo and acetylide-bridged complexes. In presence of free acetylenes, unusual ligand systems arising from C─S bond formation are observed and under certain conditions, formation of quinones by coupling of acetylenes with carbon monoxide is facilitated. 相似文献
48.
A simple and readily available oxidation of primary allylic and benzylic alcohols to the corresponding aldehydes is carried out by sodium bismuthate in acetic acid. 相似文献
49.
Here we propose an A(4) flavor symmetry model that implies a lower bound on the neutrinoless double beta decay rate, corresponding to an effective mass parameter M{ee} > or similar to 0.03 eV, and a direct correlation between the expected magnitude of CP violation in neutrino oscillations and the value of sin{2}theta{13}, as well as a nearly maximal CP phase delta. 相似文献
50.
B. Doggett S. Chakrabarti R. OHaire A. Meaney E. McGlynn M.O. Henry J.P. Mosnier 《Superlattices and Microstructures》2007,42(1-6):74
Phosphorus-doped ZnO films were grown by pulsed laser deposition using a ZnO:P2O5-doped target as the phosphorus source with the aim of producing p-type ZnO material. ZnO:P layers (with phosphorus concentrations of between 0.01 to 1 wt%) were grown on a pure ZnO buffer layer. The electrical properties of the films were characterised from temperature dependent Hall-effect measurements. The samples typically showed weak n-type conduction in the dark, with a resistivity of 70 Ω cm, a Hall mobility of μn0.5 cm2 V −1 s−1 and a carrier concentration of n3×1017 cm−3 at room temperature. After exposure to an incandescent light source, the samples underwent a change in conduction from n- to p-type, with an increase in mobility and decrease in concentration for temperatures below 300 K. 相似文献