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91.
G. C. Samanta 《International Journal of Theoretical Physics》2013,52(8):2647-2656
The exact solutions of the field equations in respect of Kantowski-Sachs universe filled with perfect fluid in the framework of f(R,T) theory of gravity (Harko et al. in Phys. Rev. D 84:024020, 2011) is derived. A cosmological model with an appropriate choice of the function f(T) is constructed. The physical behavior of the cosmological model is studied. Some important features of astrophysical phenomena, like Hubble’s parameter H(z), luminosity distance (d L ) and distance modulus μ(z) with red-shift are also discussed. 相似文献
92.
The new class of higher dimensional cosmological model of the early universe filled with perfect fluid source in the framework of f(R,T) theory of gravity (Harko et al. in Phys. Rev. D 84, 024020, 2011) is considered. A cosmological model with an appropriate choice of the function f(T) has been constructed. The physical behavior of the model is studied. The well known astrophysical phenomena, namely the Hubble parameter H(z), luminosity distance (d L ) and distance modulus μ(z) with redshift are discussed. 相似文献
93.
G. C. Samanta 《International Journal of Theoretical Physics》2013,52(12):4389-4402
In this paper, author studied homogeneous and anisotropic Bianchi type-V universe filled with matter and holographic dark energy (DE) components. The exact solutions to the corresponding Einstein’s field equations are obtained for exponential and power-law volumetric expansion. The holographic dark energy (DE) EoS parameter behaves like constant, i.e. ω Λ =?1, which is mathematically equivalent to cosmological constant (Λ) for exponential expansion of the model, whereas the holographic dark energy (DE) EoS parameter behaves like quintessence for power-law expansion of the model. A correspondence between the holographic dark energy (DE) models with the quintessence dark energy (DE) is also established. Quintessence potential and dynamics of the quintessence scalar field are reconstructed, which describe accelerated expansion of the universe. The statefinder diagnostic pair {r,s} is adopted to characterize different phases of the universe. 相似文献
94.
Alakes Maiti Bibek Patra G.P. Samanta 《International Journal of Mathematical Education in Science & Technology》2013,44(8):1061-1076
The present article deals with the problem of combined harvesting of a
Michaelis–Menten-type ratio-dependent predator–prey system. The
problem of determining the optimal harvest policy is solved by invoking
Pontryagin's Maximum Principle. Dynamic optimization of the harvest policy is
studied by taking the combined harvest effort as a dynamic variable. Computer
simulations are carried out to illustrate our analytical findings. Biological
and bioeconomical interpretations of the results are explained critically. 相似文献
95.
H. Sugimura S. Ajimura H. C. Bhang L. Busso M. Endo D. Faso T. Fukuda S. Hasegawa S. Hayakawa R. Honda Y. Ichikawa K. Imai N. Ishibashi T. Kishimoto R. Kiuchi K. Matsuda K. Matsuoka K. Miwa Y. Mizoi O. Morra S. Nagamiya M. Nakagawa H. Noumi R. Ota P. K. Saha H. Sako C. Samanta S. Sato Y. Shimizu K. Shirotori T. Soyama A. Sakaguchi T. Takahashi T. N. Takahashi T. Tanaka K. Yoshida 《Few-Body Systems》2013,54(7-10):1235-1238
We are planning to perform an experiment at J-PARC and produce new neutron-rich Λ hypernuclei by using the (π ?, K +) reaction (J-PARC E10). As the first step, we are planning to produce ${^6_{\Lambda}{\rm H}}$ hypernuclei with a 6Li target. To conduct this experiment, we are developing new detectors, those are scintillating fiber tracker, and silicon strip detector, for high rate operation to aim at increasing beam intensity up to 107/spill. As a result of beam test in Jun 2012, we are going to use high-rate beam at least 107/spill. 相似文献
96.
Eugenia Dzib José Luis Cabellos Filiberto Ortíz-Chi Sudip Pan Annia Galano Gabriel Merino 《International journal of quantum chemistry》2019,119(2):e25686
Eyringpy is a modular program for calculating thermochemical properties and rate constants for reactions in the gas phase and in solution. The code is written in Python and it has a user-friendly interface and a simple input format. Unimolecular and bimolecular reactions with one and two products are supported. Thermochemical properties are estimated through canonical ensemble and rate constants are computed according to the transition state theory. One-dimensional Wigner and Eckart tunneling corrections are also available. Rate constants of bimolecular reactions involving the formation of pre-reactive complexes are also estimated. To compute rate constants in solution, Eyringpy uses the Collins–Kimball theory to include the diffusion-limit, the Marcus theory for electron transfer processes, and the molar fractions to account for the solvent pH effect. 相似文献
97.
Charles Shearer Oriane Desaunay Stephen Zorc Alexis D. Richaud Shyam S. Samanta Nagalakshmi Jeedimalla Stéphane P. Roche 《Tetrahedron》2019,75(43):130606
4H-Pyrans (4H-Pys) and 1,4-dihydropyridines (1,4-DHPs) are important classes of heterocyclic scaffolds in medicinal chemistry. Herein, an indium(III)-catalyzed one-pot domino reaction for the synthesis of highly functionalized 4H-Pys, and a model of 1,4-DHP is reported. This alternative approach to the challenging Hantzsch 4-component reaction enables the synthesis of fused-tricyclic heterocycles, and the mechanistic studies underline the importance of an intercepted-Knoevenagel adduct to achieve higher chemoselectivity towards these types of unsymmetrical heterocycles. 相似文献
98.
Qian Wang Sudip Pan Yan‐Bo Wu Guohai Deng Jian‐Hong Bian Guanjun Wang Lili Zhao Mingfei Zhou Gernot Frenking 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(48):17526-17535
We report the synthesis and spectroscopic identification of the trisbenzene complexes of strontium and barium M(Bz)3 (M=Sr, Ba) in low‐temperature Ne matrix. Both complexes are characterized by a D3 symmetric structure involving three equivalent η6‐bound benzene ligands and a closed‐shell singlet electronic ground state. The analysis of the electronic structure shows that the complexes exhibit metal–ligand bonds that are typical for transition metal compounds. The chemical bonds can be explained in terms of weak donation from the π MOs of benzene ligands into the vacant (n?1)d AOs of M and strong backdonation from the occupied (n?1)d AO of M into vacant π* MOs of benzene ligands. The metals in these 20‐electron complexes have 18 effective valence electrons, and, thus, fulfill the 18‐electron rule if only the metal–ligand bonding electrons are counted. The results suggest that the heavier alkaline earth atoms exhibit the full bonding scenario of transition metals. 相似文献
99.
In this study, a tubular radon removal device and a movable one were prepared and investigated. The tubular radon removal device in an air conditioning return air system reduced the radon progeny by more than 84%. The radon progeny concentration reached equilibrium after 4 h when it was used only for a ventilation at the rate of 10 h−1. Radon progeny removal efficiency was above 95% for the movable radon removal device, when the ventilation rate was 17 h−1. The results showed that the radon removal devices can effectively remove the radon progeny in the air.
相似文献100.
Dr. Chaoxian Chi Dr. Sudip Pan Dr. Jiaye Jin Dr. Luyan Meng Prof. Mingbiao Luo Prof. Lili Zhao Prof. Mingfei Zhou Prof. Gernot Frenking 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(50):11772-11784
The octacarbonyl cation and anion complexes of actinide metals [An(CO)8]+/− (An=Th, U) are prepared in the gas phase and are studied by mass-selected infrared photodissociation spectroscopy. Both the octacarbonyl cations and anions have been characterized to be saturated coordinated complexes. Quantum chemical calculations by using density functional theory show that the [Th(CO)8]+ and [Th(CO)8]− complexes have a distorted octahedral (D4h) equilibrium geometry and a doublet electronic ground state. Both the [U(CO)8]+ cation and the [U(CO)8]− anion exhibit cubic structures (Oh) with a 6A1g ground state for the cation and a 4A1g ground state for the anion. The neutral species [Th(CO)8] (Oh; 1A1g) and [U(CO)8] (D4h; 5B1u) have also been calculated. Analysis of their electronic structures with the help on an energy decomposition method reveals that, along with the dominating 6d valence orbitals, there are significant 5f orbital participation in both the [An]←CO σ donation and [An]→CO π back donation interactions in the cations and anions, for which the electronic reference state of An has both occupied and vacant 5f AOs. The trend of the valence orbital contribution to the metal–CO bonds has the order of 6d≫5f>7s≈7p, with the 5f orbitals of uranium being more important than the 5f orbitals of thorium. 相似文献