Doping and energy dependences of thermal conductivity in cuprate superconductors

2017 ◽  
Vol 31 (27) ◽  
pp. 1750344 ◽  
Author(s):  
Chunsheng Ma ◽  
Rui Qi ◽  
Feng Yuan ◽  
Shaou Chen ◽  
Huaisong Zhao
Keyword(s):  
Thermal Conductivity ◽  
Doping Concentration ◽  
Cuprate Superconductors ◽  
The Other ◽  
Characteristic Peak ◽  
Characteristic Energy ◽  
Doping Dependence ◽  
Pseudogap Phase ◽  
In Doping ◽  
The One

By considering the pseudogap effect, the doping and energy dependences of thermal conductivity in cuprate superconductors are studied. Our results show that the thermal conductivity as a function of energy exhibits a characteristic peak from underdoping to overdoping due to the presence of the pseudogap in pseudogap phase of cuprate superconductors. The thermal conductivity is strongly doping dependent. On the one hand, with increasing doping concentration, the weight of thermal conductivity increases quickly, especially the residual thermal conductivity which is in qualitative agreement with the experimental data. On the other hand, the characteristic energy corresponding to the position of the characteristic peak decreases monotonically upon increasing doping concentration, and it scales with the doping dependence of pseudogap. In particular, we have studied the doping dependence of the ratio of quasiparticle velocities normal and tangential to the Fermi surface at the nodes [Formula: see text]. It is shown that [Formula: see text] increases with the increase of doping concentration. Moreover, we explain that both the residual thermal conductivity and [Formula: see text] increase rapidly upon the increase in doping concentration in heavily overdoped cuprate superconductors.

Cross-Property Relations between Elastic and Thermal Properties of Porous Ceramics

2006 ◽  
Vol 45 ◽  
pp. 107-112 ◽  
Author(s):  
W. Pabst ◽  
Eva Gregorová
Keyword(s):  
Thermal Conductivity ◽  
Elastic Moduli ◽  
Porous Alumina ◽  
Tensile Modulus ◽  
Porous Ceramics ◽  
The Other ◽  
Composite Ceramics ◽  
Shear Moduli ◽  
Property Relations ◽  
The One

The cross-property relations between the elastic moduli and the thermal conductivity of porous ceramics are reviewed from the viewpoint of micromechanics (composite theory). Consequences of the rigorous Milton-Torquato and Gibiansky-Torquato relations (in the form of bounds, i.e. inequalities derived between bulk or shear moduli on the one hand and thermal conductivity on the other) are compared to various approximate relations (equalities) recently proposed between the tensile modulus (Young’s modulus) and thermal conductivity, among them the two new cross-property relations proposed by the authors. The relations are critically discussed and applied to the case of porous alumina, zirconia and alumina-zirconia composite ceramics.

Model of electron pairs in electron-doped cuprates

2016 ◽  
Vol 30 (24) ◽  
pp. 1650170
Author(s):  
R. J. Singh ◽  
Shakeel Khan
Keyword(s):  
Magnetic Field ◽  
Order Parameter ◽  
Cuprate Superconductors ◽  
The Other ◽  
Helical Motion ◽  
Electron Pairs ◽  
Text Type ◽  
Pseudogap Phase ◽  
Pass Through ◽  
The Magnetic Field

In the order parameter of hole-doped cuprate superconductors in the pseudogap phase, two holes enter the order parameter from opposite sides and pass through various [Formula: see text] cells jumping from one [Formula: see text] to the other under the influence of magnetic field offered by the [Formula: see text] ions in that [Formula: see text] cell and thus forming hole pairs. In the pseudogap phase of electron-doped cuprates, two electrons enter the order parameter at [Formula: see text] sites from opposite ends and pass from one [Formula: see text] site to the diagonally opposite [Formula: see text] site. Following this type of path, they are subjected to high magnetic fields from various [Formula: see text] ions in that cell. They do not travel from one [Formula: see text] site to the other along straight path but by helical path. As they pass through the diagonal, they face high to low to very high magnetic field. Therefore, frequency of helical motion and pitch goes on changing with the magnetic field. Just before reaching the [Formula: see text] ions at the exit points of all the cells, the pitch of the helical motion is enormously decreased and thus charge density at these sites is increased. So the velocity of electrons along the diagonal path is decreased. Consequently, transition temperature of electron-doped cuprates becomes less than that of hole-doped cuprates. Symmetry of the order parameter of the electron-doped cuprates has been found to be of [Formula: see text] type. It has been inferred that internal magnetic field inside the order parameter reconstructs the Fermi surface, which is requisite for superconductivity to take place. Electron pairs formed in the pseudogap phase are the precursors of superconducting order parameter when cooled below [Formula: see text].

scholarly journals Use of Nanomaterials in Cryobiology and Cryomedicine

2020 ◽  
Vol 30 (4) ◽  
pp. 313-330
Author(s):  
Anatoliy Goltsev ◽  
◽  
Mykola Bondarovych ◽  
Natalya Babenko ◽  
Yuliya Gaevska ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Chemical Composition ◽  
Low Temperature ◽  
The Other ◽  
Crystal Formation ◽  
Tumor Site ◽  
Cryoprotective Agents ◽  
Functional Value ◽  
Combined Use ◽  
The One

The review considers the possibility of using modern nanotechnological developments aimed to achieve alternative cryobiological goals. On the one hand, the use of nanomaterials will increase the functional value of thawed cells due to such unique characteristics of nanoparticles as size, shape, surface charge, chemical composition, etc. Nanomaterials can be used as nanocontainers for impermeable cryoprotective agents (CPAs) and cause significant changes in crystal formation, thermal conductivity and other properties of cells, tissues and organs, that increases the efficiency of their cryopreservation. On the other hand, the combined use of nanomaterials and low-temperature freezing factors is considered a promising method of destruction of pathologically altered cells and tissues, as it minimizes the risk of recurrence of oncopathology after insufficient freezing-out of the tumor site.

scholarly journals Optimizing thermocouple’s ZT through design innovation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tinggang Zhang
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Transport Properties ◽  
Analytical Model ◽  
Power Output ◽  
Doping Concentration ◽  
Optimal Combination ◽  
Original Design ◽  
The One

AbstractThis work demonstrates that in parallel with the one existed at high doping concentration, there also exists an optimal combination of the transport properties of a thermoelectric material at low doping concentration as the curve of the relation between electrical conductivity and doping concentration is rigidly shifted toward that direction without disturbing the Seebeck coefficient and the thermal conductivity. Based on this finding, a new thermocouple design that uses low doping legs and high doping semiconductors as the external carrier injectors surrounding the legs is developed. The analytical model developed for the new thermocouple indicated that its efficiency and power output could be more than tripled as compared to those of the original design. A single thermocouple made of Silicon semiconductors was simulated numerically using different sets of input parameters. The results showed that the density of the externally injected carriers played a significant role in enhancing the thermocouple’s efficiency and power output.

Doping dependence of unusual electron spectrum in hole-doped cuprate superconductors

2016 ◽  
Vol 30 (04) ◽  
pp. 1650032 ◽  
Author(s):  
Shuhua Wang ◽  
Bingchen Han ◽  
Xiaomin Lü ◽  
Feng Yuan ◽  
Huaisong Zhao
Keyword(s):  
Electron Spectrum ◽  
Doping Concentration ◽  
Cuprate Superconductors ◽  
Mean Field Theory ◽  
Mean Field ◽  
Superconducting Order Parameter ◽  
Doping Dependence ◽  
Renormalization Factor ◽  
Underdoped Region ◽  
Self Consistent

Based on the renormalized Hubbard model, the doping dependence of electron spectrum in cuprate superconductors is discussed within the self-consistent mean field theory. It is shown that the renormalization factor [Formula: see text] (then the quasiparticle coherent weight) increases almost linearly with the doping and plays an important role in the unconventional superconductivity for cuprate superconductors. It suppresses the magnitude of the quasiparticle peak in the electron spectrum, especially in underdoped region. By calculation of the energy and doping dependence of the electron spectral function, the main features of the electron spectrum in cuprate superconductors can be described qualitatively. In particular, with the increasing doping concentration, the position of the quasiparticle peak moves to the Fermi energy and the magnitude of the quasiparticle peak increases monotonically. Our results also show that the superconducting order parameter is determined by product of the renormalization factor and the pseudogap.

scholarly journals ON A METHOD OF ASSESSMENT OF THE THERMAL TRANSFER BY CONDUCTION IN LAMINATED COMPOSITE

2016 ◽  
Vol 19 (2) ◽  
Author(s):  
RADU I. IATAN ◽  
GEORGIANA LUMINIŢA ENĂCHESCU ◽  
IULIANA IAŞNICU (STAMATE) ◽  
CARMEN T. POPA
Keyword(s):  
Thermal Conductivity ◽  
Composite Structures ◽  
Laminated Composite ◽  
Stationary Regime ◽  
The Other ◽  
Thermal Transfer ◽  
Other Hand ◽  
Laminated Composite Structures ◽  
The One ◽  
Method Of Assessment

<p>The paper explain the thermal conductivity expressions, in stationary regime, in plane, tubular and spherical, laminated composite structures, with intimate connections between layers, having defects, too. We take into account the volumes of the composite components, on the one hand, and those of the materials and fluids, contained in the defects area, on the other hand. In the corresponding relations the influences of some additional layers, representing protections or deposits during operation, are attached.</p>

scholarly journals Optimizing thermocouple’s ZT through design innovation

2021 ◽  
Author(s):  
Tinggang Zhang
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Transport Properties ◽  
Power Output ◽  
Doping Concentration ◽  
Optimal Combination ◽  
Original Design ◽  
The One ◽  
The Relationship

Abstract In this work, we demonstrate that in parallel with the one existed at high doping concentration, there also exists an optimal combination of the transport properties of a thermoelectric material at low doping concentration as the curve of the relationship between electrical conductivity and doping concentration is rigidly shifted toward lower doping concentration without disturbing the Seebeck coefficient and the thermal conductivity. Based on this finding, a new concept for thermocouple design is developed to improve the thermocouple’s efficiency and power output. The analytical model developed for the new thermocouple indicated that its efficiency and power output can be more than tripled as compared to those of the original design. A single thermocouple made of Silicon semiconductors was simulated numerically using different sets of input parameters. The results showed that the new thermocouple’s efficiency and power output can be improved significantly.

Note on Selection of Coordinate Systems for Geodynamics

1975 ◽  
Vol 26 ◽  
pp. 395-407
Author(s):  
S. Henriksen
Keyword(s):  
Sea Level ◽  
The Other ◽  
Coordinate Systems ◽  
Mean Sea Level ◽  
The Earth ◽  
The One ◽  
Static Systems ◽  
Selection Of

The first question to be answered, in seeking coordinate systems for geodynamics, is: what is geodynamics? The answer is, of course, that geodynamics is that part of geophysics which is concerned with movements of the Earth, as opposed to geostatics which is the physics of the stationary Earth. But as far as we know, there is no stationary Earth – epur sic monere. So geodynamics is actually coextensive with geophysics, and coordinate systems suitable for the one should be suitable for the other. At the present time, there are not many coordinate systems, if any, that can be identified with a static Earth. Certainly the only coordinate of aeronomic (atmospheric) interest is the height, and this is usually either as geodynamic height or as pressure. In oceanology, the most important coordinate is depth, and this, like heights in the atmosphere, is expressed as metric depth from mean sea level, as geodynamic depth, or as pressure. Only for the earth do we find “static” systems in use, ana even here there is real question as to whether the systems are dynamic or static. So it would seem that our answer to the question, of what kind, of coordinate systems are we seeking, must be that we are looking for the same systems as are used in geophysics, and these systems are dynamic in nature already – that is, their definition involvestime.

Stories and the Self

2020 ◽  
Vol 32 (2) ◽  
pp. 47-58 ◽  
Author(s):  
Stefan Krause ◽  
Markus Appel
Keyword(s):  
Meta Analysis ◽  
The Self ◽  
The Other ◽  
Lower Degree ◽  
Contrast Effects ◽  
Self Perception ◽  
Self Perceptions ◽  
Other Hand ◽  
The One ◽  
Implicit And Explicit

Abstract. Two experiments examined the influence of stories on recipients’ self-perceptions. Extending prior theory and research, our focus was on assimilation effects (i.e., changes in self-perception in line with a protagonist’s traits) as well as on contrast effects (i.e., changes in self-perception in contrast to a protagonist’s traits). In Experiment 1 ( N = 113), implicit and explicit conscientiousness were assessed after participants read a story about either a diligent or a negligent student. Moderation analyses showed that highly transported participants and participants with lower counterarguing scores assimilate the depicted traits of a story protagonist, as indicated by explicit, self-reported conscientiousness ratings. Participants, who were more critical toward a story (i.e., higher counterarguing) and with a lower degree of transportation, showed contrast effects. In Experiment 2 ( N = 103), we manipulated transportation and counterarguing, but we could not identify an effect on participants’ self-ascribed level of conscientiousness. A mini meta-analysis across both experiments revealed significant positive overall associations between transportation and counterarguing on the one hand and story-consistent self-reported conscientiousness on the other hand.

Radioimmunotherapy for treatment of acute myeloid leukaemia and myelodysplastic syndrome

2005 ◽  
Vol 44 (03) ◽  
pp. 107-117
Author(s):  
R. G. Meyer ◽  
W. Herr ◽  
A. Helisch ◽  
P. Bartenstein ◽  
I. Buchmann
Keyword(s):  
Acute Myeloid Leukaemia ◽  
Myeloid Leukaemia ◽  
Primary Tumour ◽  
The Other ◽  
Haematopoietic Stem Cell ◽  
Other Hand ◽  
Primary Reduction ◽  
The One ◽  
Acute Myeloid

SummaryThe prognosis of patients with acute myeloid leukaemia (AML) has improved considerably by introduction of aggressive consolidation chemotherapy and haematopoietic stem cell transplantation (SCT). Nevertheless, only 20-30% of patients with AML achieve long-term diseasefree survival after SCT. The most common cause of treatment failure is relapse. Additionally, mortality rates are significantly increased by therapy-related causes such as toxicity of chemotherapy and complications of SCT. Including radioimmunotherapies in the treatment of AML and myelodyplastic syndrome (MDS) allows for the achievement of a pronounced antileukaemic effect for the reduction of relapse rates on the one hand. On the other hand, no increase of acute toxicity and later complications should be induced. These effects are important for the primary reduction of tumour cells as well as for the myeloablative conditioning before SCT.This paper provides a systematic and critical review of the currently used radionuclides and immunoconjugates for the treatment of AML and MDS and summarizes the literature on primary tumour cell reductive radioimmunotherapies on the one hand and conditioning radioimmunotherapies before SCT on the other hand.

Sign in / Sign up

Export Citation Format

Share Document