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171.
J. Didier J.-J. Sinou B. Faverjon 《Communications in Nonlinear Science & Numerical Simulation》2013,18(11):3250-3270
This paper presents the concept of the Stochastic Multi-dimensional Harmonic Balance Method (Stochastic-MHBM) in order to solve dynamical problems with non-regular non linearities in presence of uncertainties. To treat the nonlinearity in the stochastic and frequency domains, the Alternate Frequency-Time method with Probabilistic Collocation (AFTPC) is proposed. The approach is demonstrated using nonlinear two-degree-of-freedom model with different types of nonlinearities (cubic nonlinearity, contact/no contact, friction). The quasi-periodic stochastic dynamic response is evaluated considering uncertainties in linear and nonlinear parts of the mechanical system. The results are compared with those obtained from the classical Monte Carlo Simulation (MCS). For various numerical tests, it is found that the results agreed very well whilst requiring significantly less computation. 相似文献
172.
Didier Felbacq 《Photonics and Nanostructures》2013,11(4):436-441
The homogenization of a metamaterial made of a collection of scatterers periodically disposed is studied from an asymptotic theory and an optimization algorithm. Detailed numerical results are given for resonant scatterers and the spatial dispersion is investigated. 相似文献
173.
Oana Moncea Juan Casanova‐Chafer Didier Poinsot Lukas Ochmann Clve D. Mboyi Houssein O. Nasrallah Eduard Llobet Imen Makni Molka ElAtrous Stphane Brands Yoann Rousselin Bruno Domenichini Nicolas Nuns Andrey A. Fokin Peter R. Schreiner Jean‐Cyrille Hierso 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(29):10038-10043
Diamondoids, sp3‐hybridized nanometer‐sized diamond‐like hydrocarbons (nanodiamonds), difunctionalized with hydroxy and primary phosphine oxide groups, enable the assembly of the first sp3‐C‐based chemical sensors by vapor deposition. Both pristine nanodiamonds and palladium nanolayered composites can be used to detect toxic NO2 and NH3 gases. This carbon‐based gas sensor technology allows reversible NO2 detection down to 50 ppb and NH3 detection at 25–100 ppm concentration with fast response and recovery processes at 100 °C. Reversible gas adsorption and detection is compatible with 50 % humidity conditions. Semiconducting p‐type sensing properties are achieved from devices based on primary phosphine–diamantanol, in which high specific area (ca. 140 m2 g?1) and channel nanoporosity derive from H‐bonding. 相似文献
174.
Dr. Margot N. Wenzel Dr. Riccardo Bonsignore Sophie R. Thomas Dr. Didier Bourissou Prof. Giampaolo Barone Prof. Angela Casini 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(32):7628-7634
With the aim of exploiting the use of organometallic species for the efficient modification of proteins through C-atom transfer, the gold-mediated cysteine arylation through a reductive elimination process occurring from the reaction of cyclometalated AuIII C^N complexes with a zinc finger peptide (Cys2His2 type) is here reported. Among the four selected AuIII cyclometalated compounds, the [Au(CCON)Cl2] complex featuring the 2-benzoylpyridine (CCON) scaffold was identified as the most prone to reductive elimination and Cys arylation in buffered aqueous solution (pH 7.4) at 37 °C by high-resolution LC electrospray ionization mass spectrometry. DFT and quantum mechanics/molecular mechanics (QM/MM) studies permitted to propose a mechanism for the title reaction that is in line with the experimental results. Overall, the results provide new insights into the reactivity of cytotoxic organogold compounds with biologically important zinc finger domains and identify initial structure–activity relationships to enable AuIII-catalyzed reductive elimination in aqueous media. 相似文献
175.
Dao Le Marco Dilger Vincent Pertici Silvia Diabat Didier Gigmes Carsten Weiss Guillaume Delaittre 《Angewandte Chemie (International ed. in English)》2019,58(14):4725-4731
We report the straightforward, time‐efficient synthesis of radical core–shell nanoparticles (NPs) by polymerization‐induced self‐assembly. A nitroxide‐containing hydrophilic macromolecular precursor was prepared by ring‐opening metathesis copolymerization of norbornenyl derivatives of TEMPO and oligoethylene glycol and was chain‐extended in situ with norbornene in ethanolic solution, leading to simultaneous amphiphilic block copolymer formation and self‐assembly. Without any intermediate purification from the monomers to the block copolymers, radical NPs with tunable diameters ranging from 10 to 110 nm are obtained within minutes at room temperature. The high activity of the radical NPs as chemoselective and homogeneous, yet readily recyclable catalysts is demonstrated through oxidation of a variety of alcohols and recovery by simple centrifugation. Furthermore, the NPs show biocompatibility and antioxidant activity in vitro. 相似文献
176.
Kalluri S Depireux DA Shamma SA 《The Journal of the Acoustical Society of America》2008,123(5):2701-2716
This study examined the perception and cortical representation of harmonic complex tones, from the perspective of the spectral fusion evoked by such sounds. Experiment 1 tested whether ferrets spontaneously distinguish harmonic from inharmonic tones. In baseline sessions, ferrets detected a pure tone terminating a sequence of inharmonic tones. After they reached proficiency, a small fraction of the inharmonic tones were replaced with harmonic tones. Some of the animals confused the harmonic tones with the pure tones at twice the false-alarm rate. Experiment 2 sought correlates of harmonic fusion in single neurons of primary auditory cortex and anterior auditory field, by comparing responses to harmonic tones with those to inharmonic tones in the awake alert ferret. The effects of spectro-temporal filtering were accounted for by using the measured spectrotemporal receptive field to predict responses and by seeking correlates of fusion in the predictability of responses. Only 12% of units sampled distinguished harmonic tones from inharmonic tones, a small percentage that is consistent with the relatively weak ability of the ferrets to spontaneously discriminate harmonic tones from inharmonic tones in Experiment 1. 相似文献
177.
Poilblanc D 《Physical review letters》2008,100(15):157206
I introduce a doped two-dimensional quantum dimer model describing a doped Mott insulator and retaining the original Fermi statistics of the electrons. This model shows a rich phase diagram including a d-wave hole-pair unconventional superconductor at small enough doping and a bosonic superfluid at large doping. The hole kinetic energy is shown to favor binding of topological defects to the bare fermionic holons turning them into bosons, in agreement with arguments based on resonating valence bond wave function. Results are discussed in the context of cuprate superconductors. 相似文献
178.
Dr. Lara Martinez-Fernandez Dr. Krishna Gavvala Dr. Rajans Sharma Prof. Pascal Didier Dr. Ludovic Richert Dr. Javier Segarra Martì Dr. Mattia Mori Prof. Yves Mely Dr. Roberto Improta 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(30):7375-7386
Thienoguanosine (thG) is an isomorphic analogue of guanosine with promising potentialities as fluorescent DNA label. As a free probe in protic solvents, thG exists in two tautomeric forms, identified as the H1, being the only one observed in nonprotic solvents, and H3 keto–amino tautomers. We herein investigate the photophysics of thG in solvents of different polarity, from water to dioxane, by combining time-resolved fluorescence with PCM/TD-DFT and CASSCF calculations. Fluorescence lifetimes of 14.5–20.5 and 7–13 ns were observed for the H1 and H3 tautomers, respectively, in the tested solvents. In methanol and ethanol, an additional fluorescent decay lifetime (≈3 ns) at the blue emission side (λ≈430 nm) as well as a 0.5 ns component with negative amplitude at the red edge of the spectrum, typical of an excited-state reaction, were observed. Our computational analysis explains the solvent effects observed on the tautomeric equilibrium. The main radiative and nonradiative deactivation routes have been mapped by PCM/TD-DFT calculations in solution and CASSCF in the gas phase. The most easily accessible conical intersection, involving an out-of plane motion of the sulfur atom in the five-membered ring of thG, is separated by a sizeable energy barrier (≥0.4 eV) from the minimum of the spectroscopic state, which explains the large experimental fluorescence quantum yield. 相似文献
179.
Sbastien Rolere Sophie Monge Mamy Daniel Rakotonirina Yohann Guillaneuf Didier Gigmes Jean‐Jacques Robin 《Journal of polymer science. Part A, Polymer chemistry》2019,57(2):120-129
Chemical modification of poly(lactic acid) (PLA) with N‐acetoxy‐phthalimide (NAPI) was performed in the melt by reactive extrusion, without using any peroxide initiator. The aminyl and nitroxide radicals produced from the NAPI thermal degradation, were, respectively, used (a) to create PLA macroradicals, and (b) to functionalize the PLA samples through nitroxide radical coupling. Depending on the extrusion temperature and the initial NAPI concentration, grafting rates up to 0.24 mol % were measured, modifying the PLA optical properties. This study represents an original new way of modification of PLA without the use of conventional peroxide initiators. Indeed, the undesirable side reactions (PLA branching or crosslinking) usually observed when using peroxides to initiate the radical grafting of PLA were avoided when using NAPI. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 120–129 相似文献
180.
Frontispiece: Dative Au→Al Interactions: Crystallographic Characterization and Computational Analysis 下载免费PDF全文