This paper gives the simplest approach to the cubic-quintic Duffing equation (M.S.H. Chowdhury et al., Results in Physics 7(2017): 3962–3967), providing an extremely fast and relatively accurate estimation of the frequency of a nonlinear conservative oscillator.
This paper gives a brief introduction to two ancient Chinese methods, Ying Buzu Shu and He Chengtian average. Their relationship is revealed, and it is proved that the two methods are equivalent under some special cases, that means He Chengtian average can be derived from the method of Ying Buzu Shu. Rachford-Rice equation arising in flash evaporation is used as an example for their simple application.
Via the semi-inverse method proposed by He, a variational principle is established for a system of two conservation laws which is strictly hyperbolic. Applying variational technique with variable-domain, the Rankine-Hugoniot jump relations can be readily obtained as natural conditions.
A fabric can be considered as a porous medium, its porosity size and temperature will greatly affect air/moisture permeability and thermal comfort. This paper studies the effect of temperature on the capillary rise experimentally, the experimental data reveal that a higher temperature results in a higher capillary rise, as a result, a better air/moisture permeability is predicted. This paper elucidates also a higher temperature is favorable for effective washing.
The Stanton number was originally proposed for describing heat transfer through a smooth surface. A modified one is suggested in this paper to take into account non-smooth surface or fractal surface. The emphasis is put on the heat transfer through fabrics.
No abstract is provided for this article.
No abstract is provided for this article.
This paper suggests several approaches to predict the number of elementary particles via a remarkable finite exceptional Lie symmetry groups hierarchy. This result confirms the earlier finding namely that nine elementary particles are still missing from the standard model.
Woven fabric is manifestly not a continuum and therefore Darcy’s law or its modifications, or any other differential models are invalid theoretically. A differential-difference model for air transport in discontinuous media is introduced using conservation of mass, conservation of energy, and the equation of state in discrete space and continuous time, capillary pressure is obtained by dimensional analysis.
Purpose The purpose of this paper is to find an approximate solution of a fractional differential equation. The fractional Newell–Whitehead–Segel equation (FNWSE) is used to elucidate the solution process, which is one of the nonlinear amplitude equation, and it enhances a significant role in the modeling of various physical phenomena arising in fluid mechanics, solid-state physics, optics, plasma physics, dispersion and convection systems. Design/methodology/approach In Part 1, the authors adopted Mohand transform to find the analytical solution of FNWSE. In this part, the authors apply the fractional complex transform (the two-scale transform) to convert the problem into its differential partner, and then they introduce the homotopy perturbation method (HPM) to bring down the nonlinear terms for the approximate solution. Findings The HPM makes numerical simulation for the fractional differential equations easy, and the two-scale transform is a strong tool for fractal models. Originality/value The HPM with the two-scale transform sheds a bright light on numerical approach to fractional calculus.
Article A Classical Variational Model for Micropolar Elastodynamics was published on June 1, 2000 in the journal International Journal of Nonlinear Sciences and Numerical Simulation (volume 1, issue 2).
We establish a variational model for one-dimensional tube flow with a more general form of pressure-density relation. Applying the semi-inverse method proposed by He, a family of variational principle for the discussed problem is systematically derived directly from the field equations and boundary / initial conditions.
A polar bear (Ursus maritimus) has superior ability to survive in harsh Arctic regions, why does the animal have such an excellent thermal protection? The present paper finds that the unique labyrinth cavity structure of the polar bear hair plays an important role. The hair can not only prevent body temperature loss but can also absorb energy from the environment.
No abstract is provided for this article.
An improved simple equation to calculate the minority-carrier effective lifetime in photoconductance measurements is proposed by the perturbation method. When the given constraints are satisfied, the given formulation leads to a fast and accurate determination of effective lifetime from the bulk lifetime, surface recombination velocity, the thickness of the wafer, and diffusion coefficient.
5G communication technology has been skyrocketing, and has changed everything in our daily lives, and its applications in various fields are also promising. However, the thermal conductivity/dissipation problems of highly integrated electronic devices and electrical equipment are becoming more and more prominent, and thermodynamics offers a solution, and fractal meta-surfaces provides an extremely efficient approach to transfer the generated waste heat, which can be used for thermal energy harvesting, and a fractal thermodynamic model is developed for thermal management.
