다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

In this chapter, we will restrict our attention to the ferrites and a few other closely related materials. The great interest in ferrites stems from their unique combination of a spontaneous magnetization and a high electrical resistivity. The observed magnetization results from the difference in the magnetizations of two non-equivalent sub-lattices of the magnetic ions in the crystal structure. Materials of this type should strictly be designated as “ferrimagnetic” and in some respects are more closely related to anti-ferromagnetic substances than they are to ferromagnetics in which the magnetization results from the parallel alignment of all the magnetic moments present. We shall not adhere to this special nomenclature except to emphasize effects, which are due to the existence of the sub-lattices.

Ferromagnetic materials

The proximity effect at superconductor-ferromagnet interfaces produces damped oscillatory behavior of the Cooper pair wave function within the ferromagnetic medium. This is analogous to the inhomogeneous superconductivity, predicted long ago by Fulde and Ferrell (P. Fulde and R. A. Ferrell, 1964, ``Superconductivity in a strong spin-exchange field,'' Phys. Rev. 135, A550--A563), and by Larkin and Ovchinnikov (A. I. Larkin and Y. N. Ovchinnikov, 1964, ``Inhomogeneous state of superconductors,'' Zh. Eksp. Teor. Fiz. 47, 1136--1146 [Sov. Phys. JETP 20, 762--769 (1965)]), and sought by condensed-matter experimentalists ever since. This article offers a qualitative analysis of the proximity effect in the presence of an exchange field and then provides a description of the properties of superconductor-ferromagnet heterostructures. Special attention is paid to the striking nonmonotonic dependence of the critical temperature of multilayers and bilayers on the ferromagnetic layer thickness as well as to the conditions under which ``$\ensuremath{\pi}$'' Josephson junctions are realized. Recent progress in the preparation of high-quality hybrid systems has permitted the observation of many interesting experimental effects, which are also discussed. Finally, the author analyzes the phenomenon of domain-wall superconductivity and the influence of superconductivity on the magnetic structure in superconductor-ferromagnet bilayers.

Proximity effects in superconductor-ferromagnet heterostructures

This review considers unusual effects in superconductor-ferromagnet structures, in particular, the triplet component of the condensate generated in those systems. This component is odd in frequency and even in momentum, which makes it insensitive to nonmagnetic impurities. If the exchange field is not homogeneous in the system, the triplet component is not destroyed even by a strong exchange field and can penetrate the ferromagnet over long distances. Some other effects considered here and caused by the proximity effect are enhancement of the Josephson current due to the presence of the ferromagnet, induction of a magnetic moment in superconductors resulting in a screening of the magnetic moment, and formation of periodic magnetic structures due to the influence of the superconductor. Finally, theoretical predictions are compared with existing experiments.

https://arxiv.org/pdf/cond-mat/0506047.pdf

Odd triplet superconductivity and related phenomena in superconductor-ferromagnet structures

By modeling a superconducting polycrystalline film as a network of superconducting grains coupled via Josephson junctions, various authors have shown that rf losses at the grain boundaries can be the main source of the residual surface resistance in high-${\mathit{T}}_{\mathit{c}}$ superconductors. The same model is extended here to include the effect of dc or rf applied fields and is then shown to be consistent with previous results on the surface impedance of low-${\mathit{T}}_{\mathit{c}}$ superconducting polycrystalline films. The model also provides a satisfactory, though qualitative, description of recent results on the quality factor of niobium thin-film-coated rf cavities for particle accelerators.

Residual surface resistance of polycrystalline superconductors

An anomalous superconducting transition consisting of a very sharp peak in the resistance versus temperature curve just above ${\mathit{T}}_{\mathit{c}}$ has been observed in (NbV)N films and other superconducting compounds. Using a simple concentrated constant-equivalent circuit, it is proved that sample nonhomogeneity together with an out-of-line contact arrangement can produce the observed effect.

Explanation of the resistance-peak anomaly in nonhomogeneous superconductors.

The proximity effect between a superconductor S and a weak ferromagnet F in sputtered Nb/Pd0.86Ni0.14
bilayers has been studied. The dependence of the critical temperature on the S- and F-layer thicknesses can be
interpreted in the framework of recent theoretical models and yields reasonable numbers for the exchange
energy of the ferromagnet and the interface transparency of the S/F barrier.

/pdf/superconducting-proximity-effect-and-interface-transparency-1ynitecaz7.pdf

Superconducting proximity effect and interface transparency in Nb/PdNi bilayers

We have investigated, in the framework of the proximity effect theory, the
interface transparency T between Nb and Cu in the case of high quality
Nb/Cu trilayers fabricated by molecular beam epitaxy (MBE) and sputtering
deposition techniques. The obtained T values do not seem to be strongly
influenced by the fabrication methods but more by the intrinsic properties of
the two metals; a slightly higher value for T has even been deduced for the
MBE prepared samples. The proximity effect in these samples has also been
studied in the presence of an external magnetic field. In the parallel
configuration a significant shift towards lower values of the 2D–3D
crossover temperature has been observed for MBE samples, in good
agreement with very recent theoretical predictions. In the perpendicular case
a positive curvature of the temperature dependence of the upper critical field
has been detected, which was less pronounced for sputtered samples. Both
the effects have been observed only for trilayers with low Nb
thickness (<600 A) which confirms the crucial influence of the interface
transparency on the values of the upper critical field in such samples.

/pdf/interface-transparency-and-proximity-effect-in-nb-cu-triple-4gkyinoqim.pdf

Interface transparency and proximity effect in Nb/Cu triple layers realized by sputtering and molecular beam epitaxy

We have observed a nonmonotonic behavior of the superconducting critical temperature ${T}_{c}$ versus the CuMn layer thickness in multilayers of Nb/CuMn with fixed Nb layer thickness (\ensuremath{\sim}250 \AA{}). The results have been interpreted assuming the presence of the $\ensuremath{\pi}$ phase in the case of layered superconducting systems with weak magnetic coupling, where the phase $\ensuremath{\varphi}$ of the superconducting order parameter can vary in the range $0l\ensuremath{\varphi}l\ensuremath{\pi}$ between adjacent superconducting layers.

Carmine Attanasio

Papers

Residual surface resistance of polycrystalline superconductors

Explanation of the resistance-peak anomaly in nonhomogeneous superconductors.

Superconducting proximity effect and interface transparency in Nb/PdNi bilayers

Interface transparency and proximity effect in Nb/Cu triple layers realized by sputtering and molecular beam epitaxy

Superconducting-critical-temperature oscillations in Nb/CuMn multilayers.