scholarly journals QUASIOPTICAL SOLID-STATE GENERATOR WITH OPEN QUASI-FREQUENCY SPHEREOSELETAL OSCILLATING SYSTEM

Author(s):  
Ivan Olkhovskiy ◽  
Anatoliy Fursov

The results of research related to the development of an effective high-Q open oscillatory system of quasi-optical solid-state generators of millimeter and submillimeter wavelength ranges are presented. It is shown that for the stable operation of solid-state generators based on Gunn diodes and avalanche-transit diodes (ATDs) located inside an open resonator (OR), a significant rarefaction of the resonance frequency spectrum is required, which excludes jumps of the generation frequency. Taking this requirement into account, a spheroechelett  open resonator (SE OR) is proposed as an open oscillatory system of solid-state generators, one of the mirrors of which is a reflective lattice of the “echelette” type. The paper presents the results of “cold” measurements of the spectrum of resonance frequencies of the SE OP, which indicate that the SE OP indeed has a significantly rarefied spectrum both in transverse and, which is very important, in longitudinal modes of oscillations. The conditions necessary for the excitation of high-quality stable oscillations with high energy efficiency in a solid-state generator based on an SE OR are discussed and implemented. The results of an experimental study of a quasi-optical generator based on an 8-mm ATD wavelength range are presented. The analysis of the obtained characteristics and their qualitative explanation on the basis of the proposed model of the processes occurring in the investigated generator are presented. It is shown that the SE OR can be used as a resonant system in the entire EHF range of not only solid-state, but also electronic-vacuum devices. Finally, a way is outlined in the direction of further rarefaction of the spectrum of the SE OR in order to create a really single-frequency open oscillatory system.

Author(s):  
W. A. Chiou ◽  
N. L. Jeon ◽  
Genbao Xu ◽  
M. Meshii

For many years amorphous metallic alloys have been prepared by rapid quenching techniques such as vapor condensation or melt quenching. Recently, solid-state reactions have shown to be an alternative for synthesizing amorphous metallic alloys. While solid-state amorphization by ball milling and high energy particle irradiation have been investigated extensively, the growth of amorphous phase by cold-rolling has been limited. This paper presents a morphological and structural study of amorphization of Cu and Ti foils by rolling.Samples of high purity Cu (99.999%) and Ti (99.99%) foils with a thickness of 0.025 mm were used as starting materials. These thin foils were cut to 5 cm (w) × 10 cm (1), and the surface was cleaned with acetone. A total of twenty alternatively stacked Cu and Ti foils were then rolled. Composite layers following each rolling pass were cleaned with acetone, cut into half and stacked together, and then rolled again.


2002 ◽  
Vol 58 (11-12) ◽  
pp. 6
Author(s):  
A. V. Arkhipov ◽  
O. I. Bilous ◽  
A. P. Koretskiy ◽  
Anatoly Ivanovich Fisun

2019 ◽  
Author(s):  
Georg Dewald ◽  
Saneyuki Ohno ◽  
Marvin Kraft ◽  
Raimund Koerver ◽  
Paul Till ◽  
...  

<p>All-solid-state batteries are often expected to replace conventional lithium-ion batteries in the future. However, the practical electrochemical and cycling stability of the best-conducting solid electrolytes, i.e. lithium thiophosphates, are still critical issues that prevent long-term stable high-energy cells. In this study, we use <i>stepwise</i><i>cyclic voltammetry </i>to obtain information on the practical oxidative stability limit of Li<sub>10</sub>GeP<sub>2</sub>S<sub>12</sub>, a Li<sub>2</sub>S‑P<sub>2</sub>S<sub>5</sub>glass, as well as the argyrodite Li<sub>6</sub>PS<sub>5</sub>Cl solid electrolytes. We employ indium metal and carbon black as the counter and working electrode, respectively, the latter to increase the interfacial contact area to the electrolyte as compared to the commonly used planar steel electrodes. Using a stepwise increase in the reversal potentials, the onset potential at 25 °C of oxidative decomposition at the electrode-electrolyte interface is identified. X‑ray photoelectron spectroscopy is used to investigate the oxidation of sulfur(-II) in the thiophosphate polyanions to sulfur(0) as the dominant redox process in all electrolytes tested. Our results suggest that after the formation of these decomposition products, significant redox behavior is observed. This explains previously reported redox activity of thiophosphate solid electrolytes, which contributes to the overall cell performance in solid-state batteries. The <i>stepwise cyclic voltammetry</i>approach presented here shows that the practical oxidative stability at 25 °C of thiophosphate solid electrolytes against carbon is kinetically higher than predicted by thermodynamic calculations. The method serves as an efficient guideline for the determination of practical, kinetic stability limits of solid electrolytes. </p>


2019 ◽  
Author(s):  
Georg Dewald ◽  
Saneyuki Ohno ◽  
Marvin Kraft ◽  
Raimund Koerver ◽  
Paul Till ◽  
...  

<p>All-solid-state batteries are often expected to replace conventional lithium-ion batteries in the future. However, the practical electrochemical and cycling stability of the best-conducting solid electrolytes, i.e. lithium thiophosphates, are still critical issues that prevent long-term stable high-energy cells. In this study, we use <i>stepwise</i><i>cyclic voltammetry </i>to obtain information on the practical oxidative stability limit of Li<sub>10</sub>GeP<sub>2</sub>S<sub>12</sub>, a Li<sub>2</sub>S‑P<sub>2</sub>S<sub>5</sub>glass, as well as the argyrodite Li<sub>6</sub>PS<sub>5</sub>Cl solid electrolytes. We employ indium metal and carbon black as the counter and working electrode, respectively, the latter to increase the interfacial contact area to the electrolyte as compared to the commonly used planar steel electrodes. Using a stepwise increase in the reversal potentials, the onset potential at 25 °C of oxidative decomposition at the electrode-electrolyte interface is identified. X‑ray photoelectron spectroscopy is used to investigate the oxidation of sulfur(-II) in the thiophosphate polyanions to sulfur(0) as the dominant redox process in all electrolytes tested. Our results suggest that after the formation of these decomposition products, significant redox behavior is observed. This explains previously reported redox activity of thiophosphate solid electrolytes, which contributes to the overall cell performance in solid-state batteries. The <i>stepwise cyclic voltammetry</i>approach presented here shows that the practical oxidative stability at 25 °C of thiophosphate solid electrolytes against carbon is kinetically higher than predicted by thermodynamic calculations. The method serves as an efficient guideline for the determination of practical, kinetic stability limits of solid electrolytes. </p>


Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1171
Author(s):  
Halina Kaczmarek ◽  
Patryk Rybczyński ◽  
Piotr Maćczak ◽  
Aleksander Smolarkiewicz-Wyczachowski ◽  
Marta Ziegler-Borowska

Chitosan was used as a protective matrix for the photosensitive dye-squaraine (2,4-bis[4-(dimethylamino)phenyl]cyclobutane-1,3-diol). The physicochemical properties of the obtained systems, both in solution and in a solid-state, were investigated. However, it was found that diluted chitosan solutions with a few percent additions of dye show an intense fluorescence, which is suppressed in the solid-state. This is related to the morphology of the heterogeneous modified chitosan films. The important advantage of using a biopolymer matrix is the prevention of dye degradation under the influence of high energy ultraviolet (UV) radiation while the dye presence improves the chitosan heat resistance. It is caused by mutual interactions between macromolecules and dye. Owing to the protective action of chitosan, the dye release in liquid medium is limited. Chitosan solutions with a few percent additions of squaraine can be used in biomedical imaging thanks to the ability to emit light, while chitosan films can be protective coatings resistant to high temperatures and UV radiation.


RSC Advances ◽  
2021 ◽  
Vol 11 (45) ◽  
pp. 27801-27811
Author(s):  
M. Vandana ◽  
Y. S. Nagaraju ◽  
H. Ganesh ◽  
S. Veeresh ◽  
H. Vijeth ◽  
...  

Representation of the synthesis steps of SnO2QDs/GO/PPY ternary composites and SnO2QDs/GO/PPY//GO/charcoal asymmetric supercapacitor device.


2021 ◽  
pp. 1831-1838
Author(s):  
Xing Xing ◽  
Yejing Li ◽  
Shen Wang ◽  
Haodong Liu ◽  
Zhaohui Wu ◽  
...  

2021 ◽  
pp. 2240-2247
Author(s):  
Ritu Sahore ◽  
Zhijia Du ◽  
Xi Chelsea Chen ◽  
W. Blake Hawley ◽  
Andrew S. Westover ◽  
...  

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