OPERATIONAL PRINCIPLE AND CONSTRUCTIONAL BASES OF A MAGNETO OPTICAL DATA MEDIUM DISC

This communication will review the purpose of development of the magnetooptical data medium. The physical principle of recording, reading and erasing is described in this paper. The authors summarize the possible materials of the magnetooptical layers and two basic structures has been studied

Electrical activation and electron spin coherence of ultra low dose antimony implants in silicon

We implanted ultra low doses (2x10^11 cm-2) of 121Sb ions into isotopically enriched 28Si and find high degrees of electrical activation and low levels of dopant diffusion after rapid thermal annealing. Pulsed Electron Spin Resonance shows that spin echo decay is sensitive to the dopant depths, and the interface quality. At 5.2 K, a spin decoherence time, T2, of 0.3 ms is found for profiles peaking 50 nm below a Si/SiO2 interface, increasing to 0.75 ms when the surface is passivated with hydrogen. These measurements provide benchmark data for the development of devices in which quantum information is encoded in donor electron spins

Chemical Raman Enhancement of Organic Adsorbates on Metal Surfaces

Using a combination of first-principles theory and experiments, we provide a quantitative explanation for chemical contributions to surface-enhanced Raman spectroscopy for a well-studied organic molecule, benzene thiol, chemisorbed on planar Au(111) surfaces. With density functional theory calculations of the static Raman tensor, we demonstrate and quantify a strong mode-dependent modification of benzene thiol Raman spectra by Au substrates. Raman active modes with the largest enhancements result from stronger contributions from Au to their electron-vibron coupling, as quantified through a deformation potential, a well-defined property of each vibrational mode. A straightforward and general analysis is introduced that allows extraction of chemical enhancement from experiments for specific vibrational modes; measured values are in excellent agreement with our calculations.Comment: 5 pages, 4 figures and Supplementary material included as ancillary fil

On the role of spectral properties of viscous flux discretization for flow simulations on marginally resolved grids

In this note, the importance of spectral properties of viscous flux discretization in solving compressible Navier-Stokes equations for turbulent flow simulations is discussed. We studied six different methods, divided into two different classes, with poor and better representation of spectral properties at high wavenumbers. Both theoretical and numerical results have revealed that the method with better properties at high wavenumbers, denoted as $\alpha$-damping type discretization, produced superior solutions compared to the other class of methods. The proposed compact $\alpha$-damping method converged towards the direct numerical simulation (DNS) solution at lower grid resolution compared with the other class of methods and is, therefore, a better candidate for high fidelity large-eddy simulations (LES) and DNS studies.Comment: 1

Electrical activation and electron spin resonance measurements of implanted bismuth in isotopically enriched silicon-28

We have performed continuous wave and pulsed electron spin resonance measurements of implanted bismuth donors in isotopically enriched silicon-28. Donors are electrically activated via thermal annealing with minimal diffusion. Damage from bismuth ion implantation is repaired during thermal annealing as evidenced by narrow spin resonance linewidths (B_pp=12uT and long spin coherence times T_2=0.7ms, at temperature T=8K). The results qualify ion implanted bismuth as a promising candidate for spin qubit integration in silicon.Comment: 4 pages, 4 figure

The role of occupied d states in the relaxation of hot electrons in Au

We present first-principles calculations of electron-electron scattering rates of low-energy electrons in Au. Our full band-structure calculations indicate that a major contribution from occupied d states participating in the screening of electron-electron interactions yields lifetimes of electrons in Au with energies of $1.0-3.0 {\rm eV}$ above the Fermi level that are larger than those of electrons in a free-electron gas by a factor of $\sim 4.5$. This prediction is in agreement with a recent experimental study of ultrafast electron dynamics in Au(111) films (J. Cao {\it et al}, Phys. Rev. B {\bf 58}, 10948 (1998)), where electron transport has been shown to play a minor role in the measured lifetimes of hot electrons in this material.Comment: 4 pages, 2 figures, to appear in Phys. Rev.

Magic Numbers of Silicon Clusters

A structural model for intermediate sized silicon clusters is proposed that is able to generate unique structures without any dangling bonds. This structural model consists of bulk-like core of five atoms surrounded by fullerene-like surface. Reconstruction of the ideal fullerene geometry results in the formation of crown atoms surrounded by $\pi$-bonded dimer pairs. This model yields unique structures for \Si{33}, \Si{39}, and \Si{45} clusters without any dangling bonds and hence explains why these clusters are least reactive towards chemisorption of ammonia, methanol, ethylene, and water. This model is also consistent with the experimental finding that silicon clusters undergo a transition from prolate to spherical shapes at \Si{27}. Finally, reagent specific chemisorption reactivities observed experimentally is explained based on the electronic structures of the reagents.Comment: 4 pages + 3 figures (postscript files after \end{document}

Prospektív vizsgálat a sigmoideoscopia diagnosztikai érzékenységének meghatározására vastagbelet infiltráló endometriosisban

INTRODUCTION AND AIM: In the treatment of colorectal endometriosis a multidisciplinary laparoscopic resection is suggested, for this reason the correct selection of bowel infiltration is essential before surgery. PATIENTS AND METHOD: Between 2009 and 2015, 383 sigmoidoscopies were performed in patients with endometriosis. Where mucosal invasion was absent secondary signs (wall rigidity, impression, kinking, pain during the examination, suffusion) were analysed. In endoscopically confirmed cases multidisciplinary surgery was performed, the remaining patients were operated by a gynecologic team only. RESULTS: Endometriosis was endoscopically confirmed in 224 patients (58.49%), 108 of them underwent multidisciplinary operation, the negative 135 cases received gynaecological surgery. Bowel endometriosis was confirmed in 103 out of 108 cases intraoperatively, while in 8 cases of the sigmoidoscopically negative patients bowel infiltration was diagnosed intraoperatively by the gynaecological team. Complete sigmoidoscopy was performed in 43.47% of the cases. Intraluminal endometriosis was found in 4.91%, secondary signs as rigidity in 38.39%, impression in 45.54%, kinking in 57.14%, pain (in cases of examination without narcosis) in 26.06% and suffusion in 3.82% of the cases was found during sigmoidoscopy. Sigmoidoscopic examination has a 92.8% specificity and 96.2% sensitivity in cases of bowel endometriosis. CONCLUSION: Sigmoidoscopy performed by an experienced gastroenterologist is a highly sensitive examination for the diagnosis of bowel endometriosis. Orv. Hetil., 2017, 158(7), 264-269

Interface engineering of domain structures in BiFeO3 thin films

A wealth of fascinating phenomena have been discovered at the BiFeO3 domain walls, examples such as domain wall conductivity, photovoltaic effects, and magnetoelectric coupling. Thus, the ability to precisely control the domain structures and accurately study their switching behaviors is critical to realize the next generation of novel devices based on domain wall functionalities. In this work, the introduction of a dielectric layer leads to the tunability of the depolarization field both in the multilayers and superlattices, which provides a novel approach to control the domain patterns of BiFeO3 films. Moreover, we are able to study the switching behavior of the first time obtained periodic 109° stripe domains with a thick bottom electrode. Besides, the precise controlling of pure 71° and 109° periodic stripe domain walls enable us to make a clear demonstration that the exchange bias in the ferromagnet/BiFeO3 system originates from 109° domain walls. Our findings provide future directions to study the room temperature electric field control of exchange bias and open a new pathway to explore the room temperature multiferroic vortices in the BiFeO3 system