A high-current hollow cathode as a source of intense line radiation in the VUV

The VUV line emission of a high-current DC hollow cathode was investigated in the wavelength region 10 nm to 100 nm. Spectra of quadruply ionised atoms could be observed. The radiance in the Al IV lines at 13 nm and 16 nm and in the He II Lyman-series was determined by a comparison with the spectral concentration of radiant intensity of the synchrotron radiation emitted by the electron storage ring BESSY. The authors found the radiance of the lines to be reproducible within +or-25%

Ab initio quality neural-network potential for sodium

An interatomic potential for high-pressure high-temperature (HPHT) crystalline and liquid phases of sodium is created using a neural-network (NN) representation of the ab initio potential energy surface. It is demonstrated that the NN potential provides an ab initio quality description of multiple properties of liquid sodium and bcc, fcc, cI16 crystal phases in the P-T region up to 120 GPa and 1200 K. The unique combination of computational efficiency of the NN potential and its ability to reproduce quantitatively experimental properties of sodium in the wide P-T range enables molecular dynamics simulations of physicochemical processes in HPHT sodium of unprecedented quality.Comment: 8 pages, 11 figures, 2 table

How to not induce SNAs: The insufficiency of directional force.

People respond faster to smaller numbers in their left space and to larger numbers in their right space. Here we argue that movements in space contribute to the formation of spatial-numerical associations (SNAs). We studied the impact of continuous isometric forces along the horizontal or vertical cardinal axes on SNAs while participants performed random number production and arithmetic verification tasks. Our results suggest that such isometric directional force do not suffice to induce SNAs. [Abstract copyright: Copyright: © 2023 Michirev et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Circular dichroism of magneto-phonon resonance in doped graphene

Polarization resolved, Raman scattering response due to E$_{2g}$ phonon in monolayer graphene has been investigated in magnetic fields up to 29 T. The hybridization of the E$_{2g}$ phonon with only the fundamental inter Landau level excitation (involving the n=0 Landau level) is observed and only in one of the two configurations of the circularly crossed polarized excitation and scattered light. This polarization anisotropy of the magneto-phonon resonance is shown to be inherent to relatively strongly doped graphene samples, with carrier concentration typical for graphene deposited on SiO$_2$

Klinisch stumme Mikroemboli in der Vena Subclavia und Arteria Cerebri Media während der Hämodialyse und Hämodiafiltration

Patienten, die mittels Hämodialyse und Hämodiafiltration behandelt werden, weisen häufig sowohl eine hohe pulmonale Morbidität als auch kognitive Veränderungen auf. Die hierzu führenden pathophysiologischen Zusammenhänge sind bis heute nicht vollständig geklärt. Eine chronische Mikroembolisation, die sich durch die gepulste Dopplersonographie darstellen läßt, könnte ein möglicher Grund für diese Veränderungen sein. 24 Patienten mit chronischer Niereninsuffizienz wurden während der Hämodialyse (n=21) und Hämodiafiltration (n=3) untersucht. In verschiedenen Phasen dieser Behandlungen beschallten wir mit einer gepulsten 2 MHz-Dopplersonde die der arteriovenösen Fistel nachgeschaltete V. subclavia. Bei zwei dieser Patienten und einem zusätzlichen Patienten leiteten wir mit Hilfe der transkraniellen Dopplersonographie auch aus einer A. cerebri media während der extrakorporalen Therapie ab und testeten zusätzlich auf das Vorliegen eines Rechts-Links-Shunts. Bei allen untersuchten Perioden der Hämodialyse und Hämodiafiltration (Ankopplung, Dialyse, Abkopplung) konnten wir zahlreiche Mikroembolisignale in der Vena subclavia nachweisen. Bei keinem der drei Patienten konnten Mikroembolisignale in der A. cerebri media nachgewiesen werden, und es wurde auch kein Rechts-Links-Shunt entdeckt. Die Zusammensetzung (gasförmig oder fest) und die Herkunft (aus dem Dialysator, der Pumpe oder dem Shunt) der Mikroemboli konnte nicht geklärt werden. Eine chronische Mikroembolisation könnte aber ein Grund für pulmonale und im Falle eines Rechts-Links-Shunts auch zerebrale Komplikationen sein. Die in dieser Arbeit beschriebene Technik kann helfen, die genutzten Geräte und Techniken zu optimieren

The Influence of Halide Substituents on the Structural and Magnetic Properties of Fe6_{6}Dy3_{3} Rings

We report the synthesis and magnetic properties of three new nine-membered Fe(III)-Dy(III) cyclic coordination clusters (CCCs), with a core motif of [Fe$_{6}$Dy$_{3}$(μ-OMe)$_{9}$(vanox)$_{6}$(X-benz)$_{6}$] where the benzoate ligands are substituted in the para-position with X = F (1), Cl (2), Br (3). Single crystal X-ray diffraction structure analyses show that for the smaller fluorine or chlorine substituents the resulting structures exhibit an isostructural Fe$_{6}$Dy$_{3}$ core, whilst the 4-bromobenzoate ligand leads to structural distortions which affect the dynamic magnetic behavior. The magnetic susceptibility and magnetization of 1-3 were investigated and show similar behavior in the dc (direct current) magnetic data. Additional ac (alternating current) magnetic measurements show that all compounds exhibit frequency-dependent and temperature-dependent signals in the in-phase and out-of-phase component of the susceptibility and can therefore be described as field-induced SMMs. The fluoro-substituted benzoate cluster 1 shows a magnetic behavior closely similar to that of the corresponding unsubstituted Fe$_{6}$Dy$_{3}$ cluster, with U$_{eff}$ = 21.3 K within the Orbach process. By increasing the size of the substituent toward 4-chlorobenzoate within 2, an increase of the energy barrier to U$_{eff}$ = 36.1 K was observed. While the energy barrier becomes higher from 1 to 2, highlighting that the introduction of different substituents on the benzoate ligand in the para-position has an impact on the magnetic properties, cluster 3 shows a significantly different SMM behavior where U$_{eff}$ is reduced in the Orbach regime to only 4.9 K

High current hollow cathode as a radiometric transfer standard source for the extreme vacuum ultraviolet

A high current hollow cathode source has been developed as a radiometric source standard for the extreme VUV. The source is operated at a constant current of 2 A with an aluminum cathode and helium or argon as buffer gas at pressures of ~1 hPa. The radiance of spectral lines in the wavelength range from 13 to 60 nm has been determined by comparison to the calculable spectral radiant power of the electron storage ring BESSY. An uncertainty of the order of 13% has been achieved for most of the investigated lines. The spectral emission is stable to better than 5% for an operating time of 30 h. An exchange of the cathode restores the original radiance

An undecanuclear ferrimagnetic Cu9Dy2 SMM achieved through ligand fine-tuning

We describe the concept of increasing the nuclearity of a previously reported high-spin Cu5Gd2 core using a “fine tuning” ligand approach. Thus two Cu9Ln2 coordination clusters, with Ln = Dy (1), Gd(2) were synthesized with the Gd compound having a ground spin state of 17/2 and the Dy analogue showing SMM behavior in zero field