scholarly journals Влияние gamma-облучения и допирования диоксидом кремния на свойства политетрафторэтилена

2019 ◽  
Vol 61 (7) ◽  
pp. 1386
Author(s):  
В.М. Егоров ◽  
П.Н. Якушев ◽  
М.А. Арсентьев ◽  
А.С. Смолянский
Keyword(s):  
Phase Transition ◽  
Structural Changes ◽  
Mechanical Analysis ◽  
Thermal Capacity ◽  
Transition Theory ◽  
Glass Transitions ◽  
First Order ◽  
First Order Phase Transition ◽  
First Order Phase ◽  
Academy Of Sciences

V. M. Egorov1, P. N. Yakushev1, M. A. Arsentiev2,3, A.S. Smoliansky2,3. 1Ioffe Institute, Russian Academy of Sciences, St. Petersburg, Russia 2 Branch of JSC Karpov NIFHI, Moscow, Russia 3 Mendeleev University of Chemical Technology, Moscow, Russia A comparative analysis for the melting of Polytetrafluoroethylene both in the initial and irradiated state and for composition with 1% "green" silica has been carried out. The method of Dynamic Mechanical Analysis was used to characterize the glass transitions for all compositions studied. The calculation based on the smeared first-order phase transition theory for the contours of the thermal capacity peaks made it possible to reveal the features of structural changes in the composite and in the irradiated Polytetrafluoroethylene.

scholarly journals Фазовые и релаксационные переходы в политетрафторэтилене

2018 ◽  
Vol 60 (9) ◽  
pp. 1824
Author(s):  
В.М. Егоров ◽  
П.Н. Якушев
Keyword(s):  
Phase Transition ◽  
Mechanical Analysis ◽  
Transition Theory ◽  
Scanning Calorimetry ◽  
First Order ◽  
Relaxation Transitions ◽  
First Case ◽  
First Order Phase Transition ◽  
First Order Phase ◽  
True Values

AbstractComparative analysis of phase and relaxation transitions in poly(tetrafluoroethylene) by differential scanning calorimetry and dynamic mechanical analysis has been carried out. Elimination of procedural errors in the first case has allowed us to obtain true values of thermodynamic parameters for phase transitions and reveal their nature. Quantitative analysis of heat capacity peak profile was performed on the basis of smeared first-order phase transition theory and relaxation glass transition has been characterized.

scholarly journals Intramolecular Rotational Phase-Transition in Bulk and Adsorbed Fe(CO)5 on (0001) Graphite*

1988 ◽  
Vol 43 (10) ◽  
pp. 855-858 ◽  
Author(s):  
R. Brener ◽  
H. Shechter
Keyword(s):  
Phase Transition ◽  
Order Phase Transition ◽  
Structural Changes ◽  
Abrupt Change ◽  
Iron Pentacarbonyl ◽  
Sharp Transition ◽  
First Order ◽  
First Order Phase Transition ◽  
First Order Phase ◽  
Rotational Phase

Abstract Mossbauer spectroscopy results on bulk iron pentacarbonyl Fe(CO)5 and as adsorbate on (0001) graphite display a sharp transition at ~ 110K. related to intramolecular hindered rotations of CO-ligands, with no associated structural changes. The hysteresis in the temperature dependence of the quadrupole splitting and the abrupt change in the spectral intensity suggest a cooperative first-order phase transition.

scholarly journals Gravitational wave signals of dark matter freeze-out

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Danny Marfatia ◽  
Po-Yan Tseng
Keyword(s):  
Phase Transition ◽  
Dark Matter ◽  
Gravitational Waves ◽  
Order Phase Transition ◽  
First Order ◽  
Stochastic Background ◽  
First Order Phase Transition ◽  
Relic Abundance ◽  
First Order Phase ◽  
Freeze Out

Abstract We study the stochastic background of gravitational waves which accompany the sudden freeze-out of dark matter triggered by a cosmological first order phase transition that endows dark matter with mass. We consider models that produce the measured dark matter relic abundance via (1) bubble filtering, and (2) inflation and reheating, and show that gravitational waves from these mechanisms are detectable at future interferometers.

scholarly journals Dark Matter production from relativistic bubble walls

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Aleksandr Azatov ◽  
Miguel Vanvlasselaer ◽  
Wen Yin
Keyword(s):  
Phase Transition ◽  
Dark Matter ◽  
Electroweak Phase Transition ◽  
First Order ◽  
Matter Production ◽  
First Order Phase Transition ◽  
Relic Abundance ◽  
Higgs Portal ◽  
First Order Phase ◽  
Gravitational Background

Abstract In this paper we present a novel mechanism for producing the observed Dark Matter (DM) relic abundance during the First Order Phase Transition (FOPT) in the early universe. We show that the bubble expansion with ultra-relativistic velocities can lead to the abundance of DM particles with masses much larger than the scale of the transition. We study this non-thermal production mechanism in the context of a generic phase transition and the electroweak phase transition. The application of the mechanism to the Higgs portal DM as well as the signal in the Stochastic Gravitational Background are discussed.

Discovering a First-Order Phase Transition in the Li–CeO2 System

Nano Letters ◽  
2017 ◽  
Vol 17 (2) ◽  
pp. 1282-1288 ◽  
Author(s):  
Kaikai Li ◽  
Xiaoye Zhou ◽  
Anmin Nie ◽  
Sheng Sun ◽  
Yan-Bing He ◽  
...  
Keyword(s):  
Phase Transition ◽  
Order Phase Transition ◽  
First Order ◽  
First Order Phase Transition ◽  
First Order Phase
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