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41.
In this work, we study a new kind of dark energy (DE), which is named as "Yang-Mills condensate" (YMC). We study the stability and wde-w'de analysis of YMC DE model. Then we correspond it with quintessence, k-essence, tachyon, phantom, dilaton, DBI-essence and hessence scalar field models of DE in FRW spacetime to reconstruct potentials as well as the dynamics for these scalar fields for describing the acceleration of the universe. We also analyze the models in graphically to interpret the nature of the scalar fields and corresponding potentials. 相似文献
42.
First principles electronic structure calculations have been performed for the double perovskite Bi(2)CoMnO(6) in its non-centrosymmetric polar state using the generalized gradient approximation plus the Hubbard U approach. We find that the ferromagnetic state is more favored compared to the ferrimagnetic state with both Co and Mn in high spin states. The calculated dynamical charge tensors are anisotropic reflecting a low-symmetry structure of the compound. The magnetic structure dependent phonon frequencies indicate the presence of a weak spin-phonon coupling. Using the Berry phase method, we obtain a spontaneous ferroelectric polarization of 5.88?μC?cm(-2), which is close to the experimental value observed for a similar compound, Bi(2)NiMnO(6). 相似文献
43.
Chayan Ranjit Shuvendu Chakraborty Ujjal Debnath 《International Journal of Theoretical Physics》2013,52(3):862-876
In this work, we have considered Kaluza-Klein Cosmology for anisotropic universe where the universe is filled with Variable Modified Chaplygin Gas (VMCG). Here we find normal scalar field ? and the self interacting potential V(?) to describe the VMCG Cosmology. We have also graphically analyzed the geometrical parameters named Statefinder Parameters in anisotropic Kaluza-Klein model. Next, we have considered a Kaluza-Klein model of interacting VMCG with dark matter in the Einstein gravity framework. Here we construct the three dimensional autonomous dynamical system of equations for this interacting model with the assumption that the dark energy and the dark matter interacts between themselves and for that we also choose the interaction term. We convert that interaction term to its dimensionless form and perform stability analysis and solve them numerically. We obtain a stable scaling solution of the equations in Kaluza-Klein model and graphically represent solutions. 相似文献
44.
We assume generalized ghost Pilgrim dark energy (GGPDE) model in the presence of cold dark matter in flat FRW universe. With suitable choice of interaction term between GGPDE and cold dark matter, we investigate the nature of equation of state parameter for GGPDE. Also, we investigate the natures of dynamical scalar field models (such as quintessence, tachyon, k-essence, and dilaton dark energy) and concerned potentials through the correspondence phenomenon between GGPDE and these models. 相似文献
45.
Biplab Bhawal 《Pramana》2004,63(4):645-662
The Caltech-MIT joint LIGO project is operating three long-baseline interferometers (one of 2 km and two of 4 km) in order
to unambiguously measure the infinitesimal displacements of isolated test masses which convey the signature of gravitational
waves from astrophysical sources. An interferometric gravitational wave detector like LIGO is a complex, non-linear, coupled,
dynamic system. This article summarizes various interesting design characteristics of these detectors and techniques that
were implemented in order to reach and maintain its operating condition. Specifically, the following topics are discussed:
(i) length sensing and control, (ii) alignment sensing and control and (iii) thermal lensing which changes the performance
and operating point of the interferometer as the input power to LIGO is increased. 相似文献
46.
Transition Metal Chemistry - The title reaction has been studied spectrophotometrically and a rate-law established within the pH range 5.0 to 6.5, $$ {?... 相似文献
47.
Lokenath Debnath 《Meccanica》1969,4(2):122-128
Summary This paper considers the three-dimensional transient wave motions in a fluid produced by a moving oscillatory disturbance of frequency acting on the free surface of the fluid. The problem is treated as an initial value problem and is solved by the joint Laplace-Fourier transform method combined with the asymptotic treatment for the double Fourier inversion integrals. The explicit representation of the steady state as well as the transient solution of the problem is presented. It is shown that the ultimate steady is set up in the limit. A brief discussion on the principal behaviour of the wave motions is made.
Sommario Si considerano i moti ondosi transitori tridimensionali prodotti in un fluido da una eccitazione oscillatoria, in movimento, di frequenza che agisce sulla superficie libera. Il problema è trattato come problema di valori iniziali e viene risolto con il metodo della trasformata congiunta di Laplace-Fourier combinata con il trattamento asintotico per gli integrali doppi di inversione di Fourier. Si espone la rappresentazione in forma esplicita della soluzione di regime e di quella transitoria. Si dimostra che la condizione finale di regime viene stabilita nel passaggio al limite. Si esegue una breve discussione del principale comportamento del moto ondoso.相似文献
48.
Present communication reports the preparation of Langmuir monolayer of water-soluble anionic dye Congo red (CR) by allowing it to adsorb from the aqueous subphase onto the preformed Langmuir monolayer of anionic stearic acid using divalent metal cations Mg2+ as mediator. Isotherm and compressibility studies of SA-Mg-CR hybrid monolayer gave valuable information about the molecular organisation in the Langmuir monolayer. Absorption spectroscopic studies revealed the formation of H-aggregates in the hybrid Langmuir–Blodgett (LB) films fabricated at lower salt concentration in the subphase. Atomic Force Microscopic image gave visual evidence of distinct nanocrystalline domains in the LB monolayer film. 相似文献
49.
The effect of material anisotropy on creep of pressurized thick-walled spherical vessel has been discussed considering the large strain theory. It is found that the creep strain varies with varying anisotropy of the material. The results obtained for the anisotropic case have been compared with those obtained for the isotropic case and it is observed that the stress and strain distribution in the wall of the vessel is strikingly different for the two cases. 相似文献
50.
A compilation of new naturally occurring iridoids and secoiridoids including their glycosides, esters, aglycones, derivatives and dimers reported during mid 2008-2010 is provided with available physical and spectral data: mp, [α](D), UV, IR, circular dichroism (CD), (1)H- and (13)C-NMR as well as natural source with family and references. The important bioactivity of new and known iridoids and secoiridoids reported during this period is also highlighted. 相似文献