scholarly journals Role of Ce in Yb/Al laser fibers: prevention of photodarkening and thermal effects

2016 ◽  
Vol 24 (12) ◽  
pp. 13009 ◽  
Author(s):  
Sylvia Jetschke ◽  
Sonja Unger ◽  
Anka Schwuchow ◽  
Martin Leich ◽  
Matthias Jäger
Keyword(s):  
Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 813
Author(s):  
Bo Jiang ◽  
Dongdong Zhang ◽  
Hong Xu ◽  
Yongbing Liu ◽  
Zhanyi Cao ◽  
...  

In this work, we reported the high ductility of an extruded AZ61 magnesium alloy tube achieved by electropulsing current-assisted tension. The elongation of the alloy reached up to about 45%, which is largely superior to the majority of AZ61 wrought Mg alloys. We found that the hardening capacity of the alloy seemed to slightly increase as the electropulsing frequency increased. Furthermore, electropulsing can arouse the serrated flow phenomenon. Here we proposed an equation describing the correlation between the average amplitude and frequency: Aa = C − 6 × 10−3f, where Aa is the average amplitude, f is the frequency, and C is the constant. In addition, introducing electropulsing current pronouncedly reduced the tendency of twinning, but the twinning fraction seemed to fail depending on the electropulsing frequency. Based on microstructure analysis, we concluded that the outstanding ductility of the studied alloy was mainly due to the combined role of the thermal effects from Joule heating, the athermal effects from electron wind, and the magnetic effects from the electropulsing current. The serrated flow phenomenon occurred along stress–strain curves after electropulsing treatment, and the underlying reasons also were uncovered.


Open Physics ◽  
2009 ◽  
Vol 7 (3) ◽  
Author(s):  
Massimo Coraddu ◽  
Marcello Lissia ◽  
Piero Quarati

AbstractNon-resonant fusion cross-sections significantly higher than corresponding theoretical predictions are observed in low-energy experiments with deuterated matrix target. Models based on thermal effects, electron screening, or quantum-effect dispersion relations have been proposed to explain these anomalous results: none of them appears to satisfactory reproduce the experiments. Velocity distributions are fundamental for the reaction rates and deviations from the Maxwellian limit could play a central role in explaining the enhancement. We examine two effects: an increase of the tail of the target Deuteron momentum distribution due to the Galitskii-Yakimets quantum uncertainty effect, which broadens the energy-momentum relation; and spatial fluctuations of the Debye-Hückel radius leading to an effective increase of electron screening. Either effect leads to larger reaction rates especially large at energies below a few keV, reducing the discrepancy between observations and theoretical expectations.


2007 ◽  
Vol 75 (15) ◽  
Author(s):  
Nir Rotenberg ◽  
A. D. Bristow ◽  
Markus Pfeiffer ◽  
Markus Betz ◽  
H. M. van Driel

2013 ◽  
Vol 40 (6Part26) ◽  
pp. 440-440
Author(s):  
C Sehgal ◽  
S Hunt ◽  
B Levenback ◽  
A Wood

2019 ◽  
Vol 220 ◽  
pp. 02007
Author(s):  
A.V. Kuznetsov ◽  
V.P. Dresvyansky ◽  
O. Bukhtsoozh ◽  
S. Enkhbat ◽  
E.F. Martynovich

The possibility of the influence of thermal effects on the formation of color centers during laser femtosecond filamentation in a LiF crystal has been investigated theoretically. The conditions are formulated under which the influence of thermal effects can be noticeable.


2020 ◽  
Author(s):  
Wouter Koopman ◽  
Radwan M. Sarhan ◽  
Felix Stete ◽  
Clemens N. Z. Schmitt ◽  
Matias Bargheer

Plasmon-mediated chemistry presents an intriguing new approach to photocatalysis. However, the reaction enhancement<br>mechanism is not well understood. In particular, the relative importance of plasmon-generated hot charges and<br>photoheating are strongly debated. In this article, we evaluate the influence of microscopic photoheating on the kinetics of<br>a model plasmon-catalyzed reaction: the light-induced 4-nitrothiophenol (4NTP) to 4,4’-dimercaptoazobenzene (DMAB)<br>dimerization. Direct measurement of the reaction temperature by nanoparticle Raman-thermometry demonstrated that<br>the thermal effect plays a dominant role in the kinetic limitations of this multistep reaction. On the same time, no reaction<br>is possible by dark heating to the same temperature. This shows that plasmon nanoparticles have the unique ability to<br>enhance several steps of complex tandem reactions simultaneously. These results provide insight into the role of hot<br>electron and thermal effects in plasmonic catalysis of complex organic reactions, which highly important for the ongoing<br>development of plasmon based photosynthesis. <br>


RSC Advances ◽  
2013 ◽  
Vol 3 (17) ◽  
pp. 6065 ◽  
Author(s):  
Yolanda Sánchez-Vicente ◽  
Albertina Cabañas ◽  
Juan A. R. Renuncio ◽  
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