Search results for "element"

Diphenoxido‐Bridged Co II and Zn II Complexes of Tripodal N 2 O 2 Ligands: Stabilisation of M II ‐Coordinated Phenoxyl Radical Species

2010

Three new tripodal ligands with an N 2 O 2 donor set, namely 2-tert-butyl-6-({(2-hydroxybenzyl)[2-(2-pyridyl)ethyl]amino}-methyl)-4-methylphenol (H 2 L 1 ), 2-tert-butyl-6-({(2-hydroxybenzyl)[2-(2-pyridyl)ethyl]amino}methyl)-4-methoxy-phenol (H 2 L 2 ) and 2-tert-butyl-6-({[2-(dimethylamino)ethyl]-(2-hydroxybenzyl)amino}methyl)-4-methoxyphenol (H 2 L 3 ) have been synthesised. Treatment of the ligands with Co-(CH 3 CO 2 ) 2 ·4H 2 O or [Zn(H 2 O) 6 ][ClO 4 ] 2 in the presence of Et 3 N provides the corresponding Co II and Zn" complexes of composition [M II 2 (L 1 ) 2 ] [M = Co (1) (single-crystals are a solvate with the composition [Co II 2 (L 1 ) 2 ]·2CHCl 3 , i.e. 1·2CHCl 3 ); M = Zn (2)],…

Analysis of the U L3-edge X-ray absorption spectra in UO2 using molecular dynamics simulations

2017

This work was supported by a grant from the Swiss National Supercomputing Centre (CSCS) under the project ID s444. The resource allocation within the PSI share at CSCS and on the PSI compute cluster Merlin4 is also acknowledged. D. B. is grateful for a fellowship within the Sciex-NMS programme. A. K. was supported by Latvian Science Council Grant no. 187/2012.

Some aspects of the solid state physics of yellow arsenic

1996

Luminescent osmium(II) bi-1,2,3-triazol-4-yl complexes: photophysical characterisation and application in light-emitting electrochemical cells

2016

The series of osmium(II) complexes [Os(bpy)3-n(btz)n][PF6]2 (bpy = 2,2’-bipyridyl, btz = 1,1’-dibenzyl-4,4’-bi-1,2,3-triazolyl, 1 n = 0, 2 n = 1, 3 n = 2, 4 n = 3), have been prepared and characterised. The progressive replacement of bpy by btz leads to blue-shifted UV-visible electronic absorption spectra, indicative of btz perturbation of the successively destabilised bpy-centred LUMO. For 4, a dramatic blue-shift relative to the absorption profile for 3 is observed, indicative of the much higher energy LUMO of the btz ligand over that of bpy, mirroring previously reported data on analogous ruthenium(II) complexes. Unlike the previously reported ruthenium systems, heteroleptic complexes 2…

Detection of deuterated molecules, but not of lithium hydride, in the z = 0.89 absorber toward PKS 1830−211

2020

Deuterium and lithium are light elements of high cosmological and astrophysical importance. In this work we report the first detection of deuterated molecules and a search for lithium hydride, 7LiH, at redshift z=0.89 in the spiral galaxy intercepting the line of sight to the quasar PKS1830-211. We used ALMA to observe several submillimeter lines of ND, NH2D, and HDO, and their related isotopomers NH2, NH3, and H2^18O, in absorption against the southwest image of the quasar, allowing us to derive XD/XH abundance ratios. The absorption spectra mainly consist of two distinct narrow velocity components for which we find remarkable differences. One velocity component shows XD/XH abundances that…

Long-Lived Electronic Coherence of Iodine in the Condensed Phase: Sharp Zero-Phonon Lines in the B↔X Absorption and Emission of I2 in Solid Xe

2015

Our study of B←X absorption of molecular iodine (I2) isolated in a low-temperature crystalline xenon has revealed an exceptionally long-lived electronic coherence in condensed phase conditions. The visible absorption spectrum shows prominent vibronic structure in the form of zero-phonon lines (ZPLs) and phonon side bands (PSBs). The resolved spectrum implies weak interaction of the chromophore to the lattice degrees of freedom. The coherence extends past the vibrational period of the excited state molecule, unlike that observed in any condensed phase environment for I2 so far. The ZP transitions from the relaxing B-state populations were resolved in the hot luminescence when the 532 nm lase…

Remembrance of the historian Vicent Llombart

2017

Esta evocación muestra cómo la formación inicial que recibió Vicent Llombart en el Seminario de historia del pensamiento económico en la Universidad de Valencia fue decisiva, pero no suficiente, para entender una trayectoria rotunda por sus contribuciones. Su propósito decidido, su firme exigencia personal y su apertura intelectual permanente nos ayudan a comprender mejor a un gran historiador. This remembrance shows how the initial training that Vicent Llombart received at the Seminar on the History of Economic Thought at the University of Valencia was crucial, although not the only element, to understanding a prominent academic career with so relevant contributions. His determined purpose…

Energy analysis of a non-linear dynamic impact using FEM

2014

In the car industry, the Finite Element Method (FEM) is being more and more used to analyze the crashworthiness performance of vehicles. In order to validate the results, these impact simulations are normally compared with real crash footage and acceleration data. This paper studies the deformation- and energy output of a simple dummy model during a non-linear dynamic impact. The dummy model is crashed into an obstacle at three different velocities to observe the energy dissipated through different damping mechanisms. Furthermore, in impact simulations, material damping plays an important role in energy dissipation. However, it can be difficult to determine realistic damping parameter value…

Transition-Edge Sensors for Particle Induced X-ray Emission Measurements

2013

In this paper we present a new measurement setup, where a transitionedge sensor detector array is used to detect X-rays in particle induced X-ray emission measurements with a 2 MeV proton beam. Transition-edge sensors offer orders of magnitude improvement in energy resolution compared to conventional silicon or germanium detectors, making it possible to recognize spectral lines in materials analysis that have previously been impossible to resolve, and to get chemical information from the elements. Our sensors are cooled to the operation temperature (65 mK) with a cryogen-free adiabatic demagnetization refrigerator, which houses a specially designed X-ray snout that has a vacuum tight window…

Channeling experiments at planar diamond and silicon single crystals with electrons from the Mainz Microtron MAMI

2020

Line structures were observed for (110) planar channeling of electrons in a diamond single crystal even at a beam energy of 180 MeV . This observation motivated us to initiate dechanneling length measurements as function of the beam energy since the occupation of quantum states in the channeling potential is expected to enhance the dechanneling length. High energy loss signals, generated as a result of emission of a bremsstrahlung photon with about half the beam energy at channeling of 450 and 855 MeV electrons, were measured as function of the crystal thickness. The analysis required additional assumptions which were extracted from the numerical solution of the Fokker-Planck equation. Prel…