Authors:
Zhonglin BO
Pages: 88 - 92 Abstract: Based on the Maxwell’s electromagnetic theory and Planck’s energy quantum theory, a new theory of energy and mass relation of a photon in wave motion was developed. The theory provided a way of measuring the mass of a photon in wave motion. With innovative incorporation of chemical bond theory, a new theory of photon molecule with π chemical bond and σ chemical bond at extreme conditions was also developed. This theory clearly illustrated the mechanism of mass generation of matter as the proceeding of photon’s polymerization based on the energy conservation. It provided the sound explanation of the generation of photon string and photon membrane as the building block of the matter. It also articulated how a photon to form a stable photon dipole from spin point-charges. It also elucidated the intrinsic nature of electromagnetic waves attributed to the different pole distance of photons. PubDate: 2022-03-01 DOI: 10.12691/ijp-10-2-1 Issue No:Vol. 10, No. 2 (2022)
Authors:
Khatiashvili Nino
Pages: 93 - 101 Abstract: In the paper the unsteady incompressible fluid flow over the infinite and finite prismatic bodies is studied. Mathematically this problem is modeled as 3D Navier-Stokes equations (NSE) for the fluid velocity components with the appropriate initial-boundary conditions. The study of the fluid flow over the bodies with the sharp edges is the important problem of Aerodynamics and Hydrodynamics. We admit that near the sharp edges the velocity components are non-smooth. By the methods of mathematical physics the bounded novel exact solutions are obtained for the specific pressure. The profile of the velocity is plotted by means of “Maplesoft”. PubDate: 2022-03-20 DOI: 10.12691/ijp-10-2-2 Issue No:Vol. 10, No. 2 (2022)
Authors:
Humaira Takia; Md. Afjalur Rahman, Rahman Moshiur, M.M. Rahaman, Khokon Hossen Pages: 102 - 110 Abstract: In the impending lesson, we explore the substantive features of PbX (S, Se and Te) such as structural, elastic, electronic and optical properties using first principle calculations based on the density functional theory. Generalized gradient approximation (GGA-PBEsol) is used as an exchange-correlation functional for the structural properties of the different crystal phases. For all phases, the optimized lattice parameters display a strong covenant with the available experimental data. The three independent elastic constants (C11, C12, and C44) for all three compounds are positive and fulfill the Born stability criteria, which ensures that all phases possess the mechanical stability in nature. The most significant elastic properties like Bulk modulus (B), shear modulus (G), Young’s modulus (Y), Poisson’s ratio (ν) and elastic anisotropy (A) of the cubic-type structure of PbX (X=S, Se and Te) are estimated and observed under ambient pressure. The Cauchy pressure and Pugh’s ratio reveals that all compounds exhibit brittle nature and the band structure analysis ensures the semi-metallic character with a narrow band gap of all these phases. The obtained values of band gap are 0.23 for PbS, 0.15 eV for PbSe, and 0.58 eV for PbTe respectively. At last, it has been obtained and smeared the several optical properties such as absorption, conductivity, reflectivity, loss function, dielectric function and refractive index at the polarization vector [100] of PbX (X=S,Se and Te) in details. The higher reflectivity spectra of these compounds in the Infrared and ultraviolet regions demonstrate promise as excellent shielding materials for avoiding solar heating. PubDate: 2022-04-08 DOI: 10.12691/ijp-10-2-3 Issue No:Vol. 10, No. 2 (2022)
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