435,299 research outputs found
The Third Way of Thermal-Electric Conversion beyond Seebeck and Pyroelectric Effects
Thermal-electric conversion is crucial for smart energy control and
harvesting, such as thermal sensing and waste heat recovering. So far, people
are aware of only two ways of direct thermal-electric conversion, Seebeck and
pyroelectric effects, each with distinct working conditions and limitations.
Here, we report the third way of thermal-electric conversion beyond Seebeck and
pyroelectric effects. In contrast to Seebeck effect that requires spatial
temperature difference, the-third-way converts the time-dependent ambient
temperature fluctuation into electricity, similar to the behavior of
pyroelectricity. However, the-third-way is also distinct from pyroelectric
effect in the sense that it does not require polar materials but applies to
general conducting systems. We demonstrate that the-third-way results from the
temperature-fluctuation-induced dynamical charge redistribution. It is a
consequence of the fundamental nonequilibrium thermodynamics and has a deep
connection to the topological phase in quantum mechanics. The findings expand
our knowledge and provide new means of thermal-electric energy harvesting.Comment: 4 pages, 3 figure
On the square-free number sequence
The main purpose of this paper is to study the number of the square-free number sequence, and give two interesting asymptotic formulas for it. At last, give another asymptotic formula and a corollary
Current Dissipation in Thin Superconducting Wires: Accurate Numerical Evaluation Using the String Method
Current dissipation in thin superconducting wires is numerically evaluated by
using the string method, within the framework of time-dependent Ginzburg-Landau
equation with a Langevin noise term. The most probable transition pathway
between two neighboring current-carrying metastable states, continuously
linking the Langer-Ambegaokar saddle-point state to a state in which the order
parameter vanishes somewhere, is found numerically. We also give a numerically
accurate algorithm to evaluate the prefactors for the rate of current-reducing
transitions.Comment: 25 pages, 5 figure
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