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91.
P. Prieto M. Monti J. de la Figuera J. M. Sanz J. F. Marco 《Hyperfine Interactions》2011,201(1-3):47-55
An overview is given of the present status of parity violation tests in neutron decay and nuclear beta decay. Prospects for improved and new measurements are discussed as well. 相似文献
92.
Robert Cichon Dominik Raab Simon Hewera Andrea Lazik-Palm Jens Theysohn Stefan Landgraeber Wojciech Kowalczyk 《PAMM》2016,16(1):77-78
In recent years, femoroacetabular impingement (FAI) has become increasingly common. As published in the literature, FAI is caused by an unphysiological contact between the proximal femur and the acetabular rim, which may lead to pain, limitation of movement, and damage of cartilage. In this paper, patient-specific finite element simulations of the movement of the hip based on gait motion data and MRI segmentation were conducted to check stresses of the acetabulum and femur, and additionally whether a bony contact is present or not. The study's findings show no bony contact between femur and acetabulum, which may lead to the hypothesis that the labrum and its deformation and/or the articular capsule are involved in the mechanism of FAI. In order to verify this hypothesis more simulations including labrum and capsule must be performed. (© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
93.
Yu-Gui Li Yun-Shan Liu Fang-Ming Miao Xiao-Lan Liu Jin-Hong Cao Wei Zhou 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4):57-60
Abstract Twenty-three new α -aryl-β -nitroalkylphosphinates 3a - g were synthesized in high yields under very mild conditions. Compounds 3 consist of two pairs of diastereomeric isomers (A) and (B) 相似文献
94.
H. Keck W. Kuchen W. Kückelhaus S. Kühlborn 《Phosphorus, sulfur, and silicon and the related elements》2013,188(3-4)
Abstract Gas phase ion structures often do not correlate with those of their corresponding neutrals and many ions with unconventional structures have been found to be stable in the gas phase in contrast to their neutral counterparts. Thus, radical ions (a) and (b) are formed under EI-conditions by consecutive elimination of C2H4 from ionized triethylphosphanesulfide Et3P(S). (a) contains tricoordinated phosphorus while the structure of (b) corresponds to an ionized adduct of H2S and the “phosphinidene” Et - P. The structures have been determined on the basis of collisional activation and metastable ion spectra as well as H/D-exchange reactions. Results of semiempirical MO-calculations (MNDO) are reported. 相似文献
95.
The present work focuses on the development of an in‐operando technique based on the visible spectroscopic reflectometry (VSR) for simultaneous determination of the oxide film formation during anodizing. The establishment of the VSR as in‐operando technique requires an extensive validation by comparative in‐situ but non‐operando thickness measurements under aqueous conditions. The investigations were carried out on anodic oxide films on pure titanium. The authors demonstrate the VSR as a simple and robust method for measurement under electrolyte covering. Additionally, an empirical correction algorithm extends the limitation of the visible reflectometry in thin film thickness. Reliable film thickness values can be measured down to ≥5 nm. The in‐operando mode yields additional information about the film growth time resolved. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
96.
Hiroshi Watanabe Marcus Elstner Thomas Steinbrecher 《Journal of computational chemistry》2013,34(3):198-205
Molecular mechanics methods have matured into powerful methods to understand the dynamics and flexibility of macromolecules and especially proteins. As multinanosecond to microsecond length molecular dynamics (MD) simulations become commonplace, advanced analysis tools are required to generate scientifically useful information from large amounts of data. Some of the key degrees of freedom to understand protein flexibility and dynamics are the amino acid residue side chain dihedral angles. In this work, we present an easily automated way to summarize and understand the relevant dihedral populations. A tremendous reduction in complexity is achieved by describing dihedral timeseries in terms of histograms decomposed into Gaussians. Using the familiar and widely studied protein lysozyme, it is demonstrated that our approach captures essential properties of protein structure and dynamics. A simple classification scheme is proposed that indicates the rotational state population for each dihedral angle of interest and allows a decision if a given side chain or peptide backbone fragment remains rigid during the course of an MD simulation, adopts a converged distribution between conformational substates or has not reached convergence yet. © 2012 Wiley Periodicals, Inc. 相似文献
97.
A new environmental cell allowing for the independent synchronous collection of the near- and mid-infrared spectra (12,000–600 cm−1) in the diffuse reflection and attenuated total reflection (ATR) modes, respectively, is reported. The cell is employed to study in real time the dehydration of the phyllosilicate mineral sepiolite, Mg8Si12O30(OH)4(OH2)4·wH2O, in both its natural form and after in situ deuteration at ambient. The spectra are obtained under dynamic purging with dry N2 and compared to those of the same material conditioned over saturated salt solutions. Sepiolite is an important industrial mineral with a modulated structure of alternating tunnels and ribbons. Its mild drying is associated with pronounced vibrational spectral changes due to the removal of surface and zeolitic H2O and the concomitant structural relaxation of the ribbons. Detailed assignments are provided for the fundamental, combination and overtone spectrum of H2O confined in the tunnels of sepiolite, SiOH groups on the external surface of the particles, and Mg3OH groups in the 2:1 ribbons. The spectra are discussed in comparison to those of palygorskite (modulated phyllosilicate with narrower ribbons and tunnels), talc (trioctahedral magnesian phyllosilicate without modulation) and high-surface area silica. It is demonstrated that sepiolite exhibits three discrete states of zeolitic hydration at ambient temperature: Besides the previously known hydrated (w = 7–8) and dry (w = 0–1) states which dominate the spectra above 30% and below 3% relative humidity, respectively, a hitherto unknown intermediate (w = 4–5) is found in the 3–10% range. The new state is most conveniently identified in the near-infrared by a ν02 Mg3O-H stretching mode at 7205 cm−1 (ν01 = 3686 cm−1, X = 83.5 cm−1) and a characteristic H2O combination band at 5271 cm−1 (D2O: 3908 cm−1). 相似文献
98.
99.
Dr. Marwa Abdelmouleh Dr. Mathieu Lalande Edith Nicol Dr. Gilles Frison Prof. Dr. Guillaume van der Rest Dr. Jean-Christophe Poully 《Chemphyschem》2021,22(12):1243-1250
These last decades, it has been widely assumed that 18-crown-6-ether (CE) plays a spectator role during the chemical processes occurring in isolated host-guest complexes between peptides or proteins and CE after activation in mass spectrometers. Our present experimental and theoretical results challenge this hypothesis by showing that CE can abstract a proton or a protonated molecule from protonated peptides after activation by collisions in argon or electron capture/transfer. Furthermore, thanks to comparison between experimental and calculated values of collision cross-sections, we demonstrate that CE can change binding site after electron transfer. We also propose detailed mechanisms for these processes. 相似文献
100.
《Comptes Rendus Physique》2016,17(10):1154-1160
It has been proposed for a long time now that the reduction of the thermal conductivity by reducing the phonon mean free path is one of the best way to improve the current performance of thermoelectrics. By measuring the thermal conductance and thermal conductivity of nanowires and thin films, we show different ways of increasing the phonon scattering from low-temperature up to room-temperature experiments. It is shown that playing with the geometry (constriction, periodic structures, nano-inclusions), from the ballistic to the diffusive limit, the phonon thermal transport can be severely altered in single crystalline semiconducting structures; the phonon mean free path is in consequence reduced. The diverse implications on thermoelectric properties will be eventually discussed. 相似文献