2,240 results match your criteria: "Universitat Dortmund[Affiliation]"

Coherent spin dynamics of electrons and holes are studied in hybrid organic-inorganic lead halide perovskite FAPbBr bulk single crystals using the time-resolved Kerr ellipticity technique at cryogenic temperatures. The Larmor spin precession of the carrier spins in a magnetic field is monitored to measure the Landé -factors of electrons (+2.44) and holes (+0.

View Article and Find Full Text PDF

Melt-quenched glass formation of a family of metal-carboxylate frameworks.

Nat Commun

March 2024

Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, 100048, Beijing, China.

Metal-organic framework (MOF) glasses are an emerging class of glasses which complement traditional inorganic, organic and metallic counterparts due to their hybrid nature. Although a few zeolitic imidazolate frameworks have been made into glasses, how to melt and quench the largest subclass of MOFs, metal carboxylate frameworks, into glasses remains challenging. Here, we develop a strategy by grafting the zwitterions on the carboxylate ligands and incorporating organic acids in the framework channels to enable the glass formation.

View Article and Find Full Text PDF

Biomolecular research traditionally revolves around comprehending the mechanisms through which peptides or proteins facilitate specific functions, often driven by their relevance to clinical ailments. This conventional approach assumes that unraveling mechanisms is a prerequisite for wielding control over functionality, which stands as the ultimate research goal. However, an alternative perspective emerges from physics-based inverse design, shifting the focus from mechanisms to the direct acquisition of functional control strategies.

View Article and Find Full Text PDF

Glutaronitrile (GN) doped with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) at concentrations below and above the room-temperature conductivity optimum near 1M of Li salt is investigated using dielectric spectroscopy and shear rheology. The experiments are carried out from ambient down to the glass transition temperature Tg, which increases considerably as LiTFSI is admixed to GN. As the temperature is lowered, the conductivity optimum shifts to lower salt concentrations, while the power-law exponents connecting resistivity and molecular reorientation time remain smallest for the 1M composition.

View Article and Find Full Text PDF

Special Issue with Research Topics on "Recent Analysis and Applications of Mass Spectra on Biochemistry".

Int J Mol Sci

February 2024

Lehrstuhl für Analytische Chemie, Institut für Umweltforschung, Fakultät für Chemie und Chemische Biologie, Universität Dortmund, Otto-Hahn-Straße 6, 44221 Dortmund, Germany.

Analytical mass spectrometry applies irreplaceable mass spectrometric (MS) methods to analytical chemistry and chemical analysis, among other areas of analytical science [...

View Article and Find Full Text PDF

The glass formation and the dipolar reorientational motions in deep eutectic solvents (DESs) are frequently overlooked, despite their crucial role in defining the room-temperature physiochemical properties. To understand the effects of these dynamics on the ionic conductivity and their relation to the mechanical properties of the DES, we conducted broadband dielectric and rheological spectroscopy over a wide temperature range on three well-established carboxylic acid-based natural DESs. These are the eutectic mixtures of choline chloride with oxalic acid (oxaline), malonic acid (maline), and phenylacetic acid (phenylaceline).

View Article and Find Full Text PDF

The decay-time-dependent CP asymmetry in B_{s}^{0}→J/ψ(→μ^{+}μ^{-})K^{+}K^{-} decays is measured using proton-proton collision data, corresponding to an integrated luminosity of 6  fb^{-1}, collected with the LHCb detector at a center-of-mass energy of 13 TeV. Using a sample of approximately 349 000 B_{s}^{0} signal decays with an invariant K^{+}K^{-} mass in the vicinity of the ϕ(1020) resonance, the CP-violating phase ϕ_{s} is measured, along with the difference in decay widths of the light and heavy mass eigenstates of the B_{s}^{0}-B[over ¯]_{s}^{0} system, ΔΓ_{s}, and the difference of the average B_{s}^{0} and B^{0} meson decay widths, Γ_{s}-Γ_{d}. The values obtained are ϕ_{s}=-0.

View Article and Find Full Text PDF

The accuracy limit of chemical shift predictions for species in aqueous solution.

Phys Chem Chem Phys

February 2024

Fakultät für Chemie und Chemische Biologie, Technische Universität Dortmund, Otto-Hahn-Straße 4a, 44227 Dortmund, Germany.

Interpreting NMR experiments benefits from first-principles predictions of chemical shifts. Reaching the accuracy limit of theory is relevant for unambiguous structural analysis and dissecting theoretical approximations. Since accurate chemical shift measurements are based on using internal reference compounds such as trimethylsilylpropanesulfonate (DSS), a detailed comparison of experimental with theoretical data requires simultaneous consideration of both target and reference species ensembles in the same solvent environment.

View Article and Find Full Text PDF

This Letter reports the observation of WZγ production and a measurement of its cross section using 140.1±1.2  fb^{-1} of proton-proton collision data recorded at a center-of-mass energy of 13 TeV by the ATLAS detector at the Large Hadron Collider.

View Article and Find Full Text PDF

The first evidence for the Higgs boson decay to a Z boson and a photon is presented, with a statistical significance of 3.4 standard deviations. The result is derived from a combined analysis of the searches performed by the ATLAS and CMS Collaborations with proton-proton collision datasets collected at the CERN Large Hadron Collider (LHC) from 2015 to 2018.

View Article and Find Full Text PDF

A measurement of time-dependent CP violation in the decays of B^{0} and B[over ¯]^{0} mesons to the final states J/ψ(→μ^{+}μ^{-})K_{S}^{0}, ψ(2S)(→μ^{+}μ^{-})K_{S}^{0} and J/ψ(→e^{+}e^{-})K_{S}^{0} with K_{S}^{0}→π^{+}π^{-} is presented. The data correspond to an integrated luminosity of 6  fb^{-1} collected at a center-of-mass energy of sqrt[s]=13  TeV with the LHCb detector. The CP-violation parameters are measured to be S_{ψK_{S}^{0}}=0.

View Article and Find Full Text PDF

Dicationic Acridinium/Carbene Hybrids as Strongly Oxidizing Photocatalysts.

J Am Chem Soc

February 2024

Fakultät für Chemie und Chemische Biologie, Technische Universität Dortmund, Otto-Hahn-Str. 6, Dortmund 44227, Germany.

A new design concept for organic, strongly oxidizing photocatalysts is described based upon dicationic acridinium/carbene hybrids. A highly modular synthesis of such hybrids is presented, and the dications are utilized as novel, tailor-made photoredox catalysts in the direct oxidative C-N coupling. Under optimized conditions, benzene and even electron-deficient arenes can be oxidized and coupled with a range of -heterocycles in high to excellent yields with a single low-energy photon per catalytic turnover, while commonly used acridinium photocatalysts are not able to perform the challenging oxidation step.

View Article and Find Full Text PDF
Article Synopsis
  • Ultrafast all-optical modulation is crucial for fast signal processing on compact optical chips, but current methods struggle with slow speeds and high costs in the visible spectrum.
  • The researchers developed a new modulator using MAPbBr perovskite metasurfaces that achieve record-high modulation depth of 2500% with a rapid modulation time of 440 femtoseconds.
  • This technology leverages easy-to-fabricate and inexpensive materials, making it a promising solution for practical applications in optics.
View Article and Find Full Text PDF

Oxide electronics provide the key concepts and materials for enhancing silicon-based semiconductor technologies with novel functionalities. However, a basic but key property of semiconductor devices still needs to be unveiled in its oxidic counterparts: the ability to set or even switch between two types of carriers-either negatively (n) charged electrons or positively (p) charged holes. Here, direct evidence for individually emerging n- or p-type 2D band dispersions in STO-based heterostructures is provided using resonant photoelectron spectroscopy.

View Article and Find Full Text PDF

On the dual behaviour of water in octanol-rich aqueous -octanol mixtures: an X-ray scattering and computer simulation study.

Phys Chem Chem Phys

January 2024

Laboratoire de Physique Théorique de la Matière Condensée (UMR CNRS 7600), Sorbonne Université, 4 Place Jussieu, F75252, Paris cedex 05, France.

Aqueous -octanol ( = 1, 2, 3, and 4) mixtures from the octanol rich side are studied by X-ray scattering and computer simulation, with a focus on structural changes, particularly in what concerns the hydration of the hydroxyl-group aggregated chain-like structures, under the influence of various branching of the alkyl tails. Previous studies have indicated that hydroxyl-group chain-cluster formation is hindered in proportion to the branching number. Here, water mole fractions up to = 0.

View Article and Find Full Text PDF

How does border enforcement affect the mobility of migrants and refugees in countries of transit? What impact does it have on migrants' bodily experiences of mobility and their reliance on actors of the migration industry? While the externalization of borders affects undocumented people by increasing their vulnerability to violence during transit, the impact of the migration regime on the social construction of inequalities in every-day interactions and its relationship to the capacity for mobility has not been studied in depth. This article intends to bridge this gap: based on ethnographic fieldwork I conducted between 2013 and 2019, this article analyzes the relation between immigration enforcement and the mobility strategies of migrants and refugees, particularly women. It focuses on the intertwining of border enforcement and violence and their impact on people's bodily mobility experiences in transit through Mexico along intersecting lines of inequality such as race, class, gender and nationality.

View Article and Find Full Text PDF

BannMI deciphers potential -to-1 information transduction in signaling pathways to unravel message of intrinsic apoptosis.

Bioinform Adv

November 2023

Research Center Trustworthy Data Science and Security, Universitätsallianz Ruhr, 44227 Dortmund, North Rhine-Westphalia, Germany.

Motivation: Cell fate decisions, such as apoptosis or proliferation, are communicated via signaling pathways. The pathways are heavily intertwined and often consist of sequential interaction of proteins (kinases). Information integration takes place on the protein level via -to-1 interactions.

View Article and Find Full Text PDF

A search for events with a dark photon produced in association with a dark Higgs boson via rare decays of the standard model Z boson is presented, using 139  fb^{-1} of sqrt[s]=13  TeV proton-proton collision data recorded by the ATLAS detector at the Large Hadron Collider. The dark boson decays into a pair of dark photons, and at least two of the three dark photons must each decay into a pair of electrons or muons, resulting in at least two same-flavor opposite-charge lepton pairs in the final state. The data are found to be consistent with the background prediction, and upper limits are set on the dark photon's coupling to the dark Higgs boson times the kinetic mixing between the standard model photon and the dark photon, α_{D}ϵ^{2}, in the dark photon mass range of [5, 40] GeV except for the ϒ mass window [8.

View Article and Find Full Text PDF

A measurement of the mass of the Higgs boson combining the H→ZZ^{*}→4ℓ and H→γγ decay channels is presented. The result is based on 140  fb^{-1} of proton-proton collision data collected by the ATLAS detector during LHC run 2 at a center-of-mass energy of 13 TeV combined with the run 1 ATLAS mass measurement, performed at center-of-mass energies of 7 and 8 TeV, yielding a Higgs boson mass of 125.11±0.

View Article and Find Full Text PDF

The enol-linked intramolecular alkyne-de Mayo reaction is a photochemically triggered cascade reaction suitable for the synthesis of substituted dihydrotropones by two-carbon ring expansion of enol ethers of cyclopentane-1,3-dion. We report on the implementation of the methylene acetal linker and the isolation of the initial (2 + 2) photocycloadduct in substances. We have investigated in depth the modus operandi of the ring-opening of the π-donor-π-acceptor cyclobutene derivatives by computational chemistry.

View Article and Find Full Text PDF

Pyridinium-Derived Mesoionic N-Heterocyclic Olefins (py-mNHOs).

Angew Chem Int Ed Engl

March 2024

Fakultät für Chemie und Chemische Biologie, Technische Universität Dortmund, Otto-Hahn-Str. 6, 44227, Dortmund, Germany.

Mesoionic polarization allows access to electron-rich olefins that have found application as organocatalysts, ligands, or nucleophiles. Herein, we report the synthesis and characterization of a series of 3-methylpyridinium-derived mesoionic olefins (py-mNHOs). We used a DFT-supported design concept, which showed that the introduction of aryl groups in the 1-, 2-, 4-, and 6-positions of the heterocyclic core allowed the kinetic stabilization of the novel mesoionic compounds.

View Article and Find Full Text PDF

Exploiting π and Chalcogen Interactions for the β-Selective Glycosylation of Indoles through Glycal Conformational Distortion.

Angew Chem Int Ed Engl

February 2024

Abteilung Chemische Biologie, Max Planck Institut für Molekulare Physiologie, Otto-Hahn-Straße 11, 44227, Dortmund, Germany.

Harnessing unconventional noncovalent interactions (NCIs) is emerging as a formidable synthetic approach in difficult-to-access glycosidic chemical space. C-Glycosylation, in particular, has gained a flurry of recent attention. However, most reported methods are restricted to the relatively facile access to α-C-glycosides.

View Article and Find Full Text PDF

Reservoir computing is a concept involving mapping signals onto a high-dimensional phase space of a dynamical system called "reservoir" for subsequent recognition by an artificial neural network. We implement this concept in a nanodevice consisting of a sandwich of a semiconductor phonon waveguide and a patterned ferromagnetic layer. A pulsed write-laser encodes input signals into propagating phonon wavepackets, interacting with ferromagnetic magnons.

View Article and Find Full Text PDF

Improving the quantum coherence of solid-state systems is a decisive factor in realizing solid-state quantum technologies. The key to optimize quantum coherence lies in reducing the detrimental influence of noise sources such as spin noise and charge noise. Here we demonstrate that we can utilize highly-excited Rydberg excitons to neutralize charged impurities in the semiconductor Cuprous Oxide - an effect we call purification.

View Article and Find Full Text PDF

Using deuteron spin-lattice and spin-spin relaxometry, the reorientational dynamics of ethaline (choline chloride/ethylene glycol) and reline (choline chloride/urea) are studied in a component-selective, isotope-edited manner over a wide temperature range, thereby complementing previous work on glyceline (choline chloride/glycerol). Differences in the hydrogen bond propensities effectuate that in reline and glyceline, the choline ions move faster than the hydrogen bond donors, glycerol and urea; in ethaline, the ethylene glycol molecules are reorienting faster. For glyceline and reline, the increase in the corresponding time scale ratio indicates a pronounced strengthening of the glycerol and urea networks upon cooling, while in ethaline, the time scale ratio remains essentially constant.

View Article and Find Full Text PDF