scholarly journals Эффекты фазового перехода, индуцированные давлением, в модельных сегнетоэластиках Hg-=SUB=-2-=/SUB=-Br-=SUB=-2-=/SUB=-

2018 ◽  
Vol 44 (17) ◽  
pp. 3
Author(s):  
Е.М. Рогинский ◽  
А.С. Крылов ◽  
Ю.Ф. Марков
Keyword(s):  
Tetragonal Phase ◽  
Boundary Point ◽  
Acoustic Phonon ◽  
High Pressures ◽  
Soft Mode ◽  
Anomalous Behavior ◽  
Zone Boundary ◽  
Brillouin Zone Boundary ◽  
Wide Range ◽  
Phase Spectra

AbstractRaman spectra of model improper ferroelastics (Hg_2Br_2 crystals) have been analyzed in a wide range of hydrostatic pressures. The baric dependences of the phonon frequencies are obtained. The revealing and anomalous behavior of the soft mode, which is genetically related to the acoustic phonon (ТА_1) at the Brillouin zone boundary (point X ) of the tetragonal phase, are most interesting. The buildup of the second acoustic phonon (ТА_2) from the same point has also been found in the ferroelastic-phase spectra, and its baric behavior has been investigated. The splitting of doubly degenerate phonons of the E _g symmetry has been revealed at fairly high pressures and explained.

scholarly journals Динамика решеток и барическое поведение фононов в модельных сегнетоэластиках Hg-=SUB=-2-=/SUB=-Br-=SUB=-2-=/SUB=-

2019 ◽  
Vol 61 (2) ◽  
pp. 325
Author(s):  
Е.М. Рогинский ◽  
А.С. Крылов ◽  
Ю.Ф. Марков
Keyword(s):  
Brillouin Zone ◽  
Tetragonal Phase ◽  
High Pressures ◽  
Soft Mode ◽  
Anomalous Behavior ◽  
Zone Boundary ◽  
Brillouin Zone Boundary ◽  
Wide Range ◽  
Phase Spectra ◽  
High Hydrostatic Pressures

AbstractRaman spectra of Hg_2Br_2 model improper ferroelastic crystals have been investigated in a wide range of high hydrostatic pressures. Baric dependences of the phonon frequencies have been obtained; of greatest interest are the observed soft mode originating from the slowest TA _1 acoustic branch at the Brillouin zone boundary ( X point) of the tetragonal phase and the anomalous behavior of this mode. In the ferroelastic phase spectra, the ignition of the second acoustic TA _2 from the same point has also been detected and its baric behavior has been studied. Under sufficiently high pressures, splitting of doubly degenerate phonons with the E _ g symmetry has been observed and explained. The parameters of the Grüneisen constants have been determined from the baric dependences of the phonon frequencies and discussed.

Wide-range equations of state for organic liquids

2007 ◽  
Vol 5 ◽  
pp. 113-120 ◽  
Author(s):  
R.Kh. Bolotnova
Keyword(s):  
High Pressures ◽  
Equations Of State ◽  
Organic Liquids ◽  
Liquid Phases ◽  
Wide Range ◽  
High Pressures And Temperatures

The method of construction the wide-range equations of state for organic liquids, describing the gas and liquid phases including dissociation and ionization which occurs during an intense collapse of steam bubbles and accompanied by ultra-high pressures and temperatures, is proposed.

Anomalous behavior of CeTe under high pressures

1983 ◽  
Vol 28 (12) ◽  
pp. 7125-7129 ◽  
Author(s):  
J. M. Léger ◽  
R. Epain ◽  
J. Loriers ◽  
D. Ravot ◽  
J. Rossat-Mignod
Keyword(s):  
High Pressures ◽  
Anomalous Behavior

Respiratory Mechanics of Sound Production in Chickens and Geese

1978 ◽  
Vol 72 (1) ◽  
pp. 229-250
Author(s):  
J. H. BRACKENBURY
Keyword(s):  
Respiratory System ◽  
Simultaneous Measurement ◽  
Sound Production ◽  
High Pressures ◽  
Respiratory Mechanics ◽  
Air Flow ◽  
Tracheal Pressure ◽  
Wide Range ◽  
Range Of Values ◽  
Respiratory Movements

1. Air flow, air sac pressure and tracheal pressure were measured in chickens and geese during a variety of different vocal and non-vocal activities. 2. Air flow and air sac pressure may rise to 500 ml s−1 and 60 cmH2O (6 103 N/m2) respectively during a crow in the chicken. During a sequence of honks in the goose the corresponding values are 650 ml s−1 and 25 cmH2O(2.5 × 10 3 N/m2) respectively. 3. The volume of air delivered through the respiratory system during a single crow is more than 400 ml, almost equivalent to the total volume of the lung air sac system. 4. The efficiency of the chicken syrinx as a sound producing instrument, estimated by comparing the sound energy radiated with the energy consumed in the expulsion of air during a crow, appears to be less than 2 %. 5. Cutting the paired sternotrachealis muscles had no effect on vocalization. 6. The measured rates of clucking, cheeping and honking in adult chickens, young chicks and adult geese respectively are comparable to the characteristic rates of panting in these animals. This points to a similarity in the nature of the respiratory movements involved in each case. 7. Simultaneous measurement of tracheal flow and pressure indicate that the glottis is capable of controlling air flow over a wide range of values in the presence of high pressures. During defaecation the valve is closed whilst during coughing it is wide open.

The Design, Development and Validation of an Innovative High Strength, Self Monitoring, Composite Pipe Liner for the Restoration of Energy Transmission Pipelines

2006 ◽  
Author(s):  
Kyle Bethel ◽  
Steven C. Catha ◽  
Melvin F. Kanninen ◽  
Randall B. Stonesifer ◽  
Ken Charbonneau ◽  
...  
Keyword(s):  
High Pressures ◽  
Large Diameter ◽  
Cylindrical Tube ◽  
High Strength ◽  
Design Development ◽  
Energy Transmission ◽  
Engineering Research ◽  
Wide Range ◽  
Transmission Pipelines

The research described in this paper centers on a composite of thermoplastic materials that can be inserted in a degraded steel pipe to completely restore its strength. Through the use of fabrics consisting of ultra high strength fibers that are co-helically wrapped over a thin walled thermoplastic cylindrical tube that serves as a core, arbitrarily high pressures can be achieved. This paper first outlines the design, manufacturing and installation procedures developed for this unique material to provide a context for the engineering research. Based on this outline, the technological basis that has been developed for assuring the strength and long term durability of this concept during its insertion, and in its very long term service as a liner in energy transmission pipelines, is presented in detail. The research that is described includes burst testing of the material in stand alone pipe form, load/elongation testing of ultra high strength fabrics, and linear and nonlinear elastic and viscoelastic analysis models. This body of work indicates that the concept is fundamentally feasible for restoring a wide range of large diameter natural gas and liquid transmission pipelines to be able to carry arbitrarily high pressures over very long lifetimes. It also indicates that liners can be safely installed in long lengths even in lines with severe bends in a continuous manner. With further research the concept has the potential for eliminating hydro testing and smart pigging during service, and could possibly be installed in some lines that are currently unpiggable.

Incoherent strange metal sharply bounded by a critical doping in Bi2212

Science ◽  
2019 ◽  
Vol 366 (6469) ◽  
pp. 1099-1102 ◽  
Author(s):  
Su-Di Chen ◽  
Makoto Hashimoto ◽  
Yu He ◽  
Dongjoon Song ◽  
Ke-Jun Xu ◽  
...  
Keyword(s):  
High Temperature Superconductors ◽  
Quantum Critical Point ◽  
Critical Value ◽  
Photoemission Spectroscopy ◽  
Metallic State ◽  
Zone Boundary ◽  
Brillouin Zone Boundary ◽  
Angle Resolved Photoemission Spectroscopy ◽  
Normal Metals ◽  
Superconducting Fluctuations

In normal metals, macroscopic properties are understood using the concept of quasiparticles. In the cuprate high-temperature superconductors, the metallic state above the highest transition temperature is anomalous and is known as the “strange metal.” We studied this state using angle-resolved photoemission spectroscopy. With increasing doping across a temperature-independent critical value pc ~ 0.19, we observed that near the Brillouin zone boundary, the strange metal, characterized by an incoherent spectral function, abruptly reconstructs into a more conventional metal with quasiparticles. Above the temperature of superconducting fluctuations, we found that the pseudogap also discontinuously collapses at the very same value of pc. These observations suggest that the incoherent strange metal is a distinct state and a prerequisite for the pseudogap; such findings are incompatible with existing pseudogap quantum critical point scenarios.

scholarly journals Equation of state for rhodium at high pressures

2021 ◽  
Vol 2057 (1) ◽  
pp. 012118
Author(s):  
K V Khishchenko
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Equation Of State ◽  
Internal Energy ◽  
Specific Volume ◽  
High Pressures ◽  
Thermodynamic Characteristics ◽  
Wide Range ◽  
Hydrodynamic Processes

Abstract An equation of state has been developed for rhodium in a wide range of changes in the specific volume and internal energy. The results of calculations of the thermodynamic characteristics of this metal are presented in comparison with the available experimental data at high pressures. This equation of state can be used in the numerical simulation of hydrodynamic processes under intense impulse influences on matter.

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