scholarly journals Benchmarking report for WIGGLE: A one-dimensional transient diffusion theory code

1990 ◽  
Author(s):  
R.E. Pevey
Keyword(s):  
Diffusion Theory ◽  
One Dimensional ◽  
Transient Diffusion

Temperature Effects on Mobile Charges in Extension of Composite Fibers of Piezoelectric Dielectrics and Non-Piezoelectric Semiconductors

2019 ◽  
Vol 11 (09) ◽  
pp. 1950088 ◽  
Author(s):  
Ruoran Cheng ◽  
Chunli Zhang ◽  
Weiqiu Chen ◽  
Jiashi Yang
Keyword(s):  
Temperature Change ◽  
Composite Structures ◽  
Diffusion Theory ◽  
Composite Fiber ◽  
Macroscopic Theory ◽  
One Dimensional ◽  
Piezoelectric Effects ◽  
Potential Applications ◽  
Mobile Charges ◽  
Piezoelectric Semiconductors

We study the redistribution of mobile charge carriers in a composite fiber of piezoelectric dielectrics and non-piezoelectric semiconductors in extensional deformation under a uniform temperature change. The macroscopic theory of piezoelectricity and the drift-diffusion theory of semiconductor are used, coupled by doping and mobile charges. A one-dimensional model for extension is developed. Through a theoretical analysis, it is shown that under a temperature change the mobile charges in the semiconductor redistribute themselves under the polarization and electric field produced through thermoelastic, pyroelectric and piezoelectric effects. The results suggest the possibility of using composite structures for thermally manipulating mobile charges in semiconductors and have potential applications in piezotronics.

scholarly journals Comparison of Vacancy Sink Efficiency of Cu/V and Cu/Nb Interfaces by the Shared Cu Layer

Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2628 ◽  
Author(s):  
Huaqiang Chen ◽  
Jinlong Du ◽  
Yanxia Liang ◽  
Peipei Wang ◽  
Jinchi Huang ◽  
...  
Keyword(s):  
Incident Energy ◽  
Diffusion Theory ◽  
New Method ◽  
Helium Ions ◽  
Helium Concentration ◽  
One Dimensional ◽  
Helium Bubbles ◽  
Dimensional Diffusion ◽  
Multilayer Composites

This paper provides a new method to compare and then reveal the vacancy sink efficiencies quantitively between different hetero-interfaces with a shared Cu layer in one sample, in contrast to previous studies, which have compared the vacancy sink efficiencies of interfaces in different samples. Cu-Nb-Cu-V nanoscale metallic multilayer composites (NMMCs) containing Cu/V and Cu/Nb interfaces periodically were prepared as research samples and bombarded with helium ions to create vacancies which were filled by helium bubbles. A special Cu layer shared by adjoining Cu/V and Cu/Nb interfaces exists, in which the implanted helium concentration reaches its maximum and remains nearly constant with a well-designed incident energy. The results show that bubble-denuded zones (BDZ) close to interfaces exist, and that the width of the BDZ close to the Cu/V interface is less than that of Cu/Nb interface. This result is explained by one-dimensional diffusion theory, and the ratio of vacancy sink efficiency between Cu/V and Cu/Nb interfaces is calculated. Conclusively, Cu/Nb interfaces are more efficient than Cu/V interfaces in eliminating vacancies induced by radiation.

XIX.—A Generalization of the Classical Random-walk problem, and a Simple Model of Brownian Motion Based Thereon

1952 ◽  
Vol 63 (3) ◽  
pp. 268-279
Author(s):  
G. Klein
Keyword(s):  
Brownian Motion ◽  
Random Walk ◽  
Thermal Equilibrium ◽  
Diffusion Theory ◽  
Initial Kinetic Energy ◽  
Time Varying ◽  
Zero Energy ◽  
Discrete Probability ◽  
One Dimensional ◽  
Special Cases

SynopsisSuggested by the analogy between the classical one-dimensional random-walk and the approximate (diffusion) theory of Brownian motion, a generalization of the random-walk is proposed to serve as a model for the more accurate description of the phenomenon. Using the methods of the calculus of finite differences, some general results are obtained concerning averages based on a time-varying bivariate discrete probability distribution in which the variates stand in the particular relation of “position” and “velocity.” These are applied to the special cases of Brownian motion from initial thermal equilibrium, and from arbitrary initial kinetic energy. In the latter case the model describes accurately quantized Brownian motion of two energy states, one of zero energy.

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