scholarly journals Electronic contribution to the geometric dynamics of magnetization

2018 ◽  
Vol 98 (3) ◽  
Author(s):  
Bangguo Xiong ◽  
Hua Chen ◽  
Xiao Li ◽  
Qian Niu
2000 ◽  
Vol 660 ◽  
Author(s):  
B. Sahraoui ◽  
K.J. Pluciński ◽  
M. Makowaska-Janusik ◽  
I. V. Kityk ◽  
M. Salle ◽  
...  

ABSTRACTA study was made of third-order nonlinear optical susceptibilities of new tetrathiafulvalene (TTF) derivatives, using the degenerate four wave mixing (DFWM) method, as well as complex quantum chemical calculations. To understand the physical nature of the optical nonlinearities, we separated their electronic and nuclear contributions. We found that the electronic contribution to these nonlinearities predominated. Our investigations suggest that TTF may be a highly promising material for nonlinear optics (NLO).


2012 ◽  
Vol 501 ◽  
pp. 319-323
Author(s):  
Hasan A. Alwi ◽  
Lay S. Ewe ◽  
Zahari Ibrahim ◽  
Noor B. Ibrahim ◽  
Roslan Abd-Shukor

We report the room temperature thermal conductivity κ and thermal diffusivity α of polycrystalline La0.7Ca0.3-xSrxMnO3 for x = 0 to 0.1. The samples were prepared by heating at 1220 and 1320oC. The insulator-metal transition temperature, TIM and thermal diffusivity increased with Sr content. Phonon was the dominant contributor to thermal conductivity and the electronic contribution was less than 1%. Enhancement of electrical conductivity σ and thermal diffusivity for x ≥ 0.08 was observed in both series of samples. The grain size of the samples (28 to 46 µm) does not show any affect on the thermal and electrical properties.


Mathematics ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 79 ◽  
Author(s):  
Constantin Udriste ◽  
Ionel Tevy

The purpose of this paper is threefold: (i) to highlight the second order ordinary differential equations (ODEs) as generated by flows and Riemannian metrics (decomposable single-time dynamics); (ii) to analyze the second order partial differential equations (PDEs) as generated by multi-time flows and pairs of Riemannian metrics (decomposable multi-time dynamics); (iii) to emphasise second order PDEs as generated by m-distributions and pairs of Riemannian metrics (decomposable multi-time dynamics). We detail five significant decomposed dynamics: (i) the motion of the four outer planets relative to the sun fixed by a Hamiltonian, (ii) the motion in a closed Newmann economical system fixed by a Hamiltonian, (iii) electromagnetic geometric dynamics, (iv) Bessel motion generated by a flow together with an Euclidean metric (created motion), (v) sinh-Gordon bi-time motion generated by a bi-flow and two Euclidean metrics (created motion). Our analysis is based on some least squares Lagrangians and shows that there are dynamics that can be split into flows and motions transversal to the flows.


1972 ◽  
Vol 27 (1) ◽  
pp. 138-140 ◽  
Author(s):  
George A. Sullivan ◽  
Sune Larsson ◽  
Per T. Thernquist

Abstract Steady-state distributions of Au, Ag and Cu tracers in Pb wafers subjected to temperature gradients have been determined. The effective heats of transport were + 5.8 ± 1.1 for Ag, - 0.5 ± 0.3 for Au, and of the order of + 35 for Cu (all in kcal/mole, positive values denoting the impurity migrating to the cold side of the Pb wafer). No significant temperature dependence of the heats of transport could be detected. The results are difficult to reconcile with existing theories of the intrinsic and electronic contribution to the heat of transport.


The electronic contribution to the dynamical tensors is examined in more detail and the following results are obtained. First the electronic contribution is shown to be translationally invariant, secondly the assumption that this term can be approximately represented by a two-body interaction is shown to be equivalent to a rigid ion model, and finally this approximation is shown to become exact in the limit q = 0.


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