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排序方式: 共有147条查询结果,搜索用时 15 毫秒
91.
92.
A water droplet placed on a vibrating surface moves toward the antinode of the vibration. The acoustic radiation pressure can explain this non-linear phenomenon. In this paper, the use of a piezoelectric actuator to produce a displacement of liquid droplets is pointed out. Due to geometry of the actuator and the position of piezoelectric ceramics, it is possible to generate stationary modes in the structure where the nodal lines can move. 相似文献
93.
Dr. David Lebœuf Dr. Marc Presset Bastien Michelet Dr. Christophe Bour Dr. Sophie Bezzenine‐Lafollée Prof. Dr. Vincent Gandon 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(31):11001-11005
Direct alkenylation of a variety of alcohols with vinylboronic acids has been accomplished using the air‐stable calcium(II) complex Ca(NTf2)2 under mild conditions with short reaction times. For reluctant transformations, an ammonium salt was used as an additive to circumvent the reactivity issue. 相似文献
94.
Dr. Éric Godin Sacha Nguyen Thanh Javier Guerrero-Morales Dr. Jeffrey Santandrea Dr. Antoine Caron Clémentine Minozzi Noémie Beaucage Bastien Rey Mathieu Morency Xavier Abel-Snape Prof. Dr. Shawn K. Collins 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(64):14575-14579
The synthesis of rare macrocyclic alkynediyl sulfides by a Cu-catalyzed Csp−S cross-coupling is presented. The catalytic protocol (Cu(MeCN)4PF6/dtbbpy) promotes macrocyclization of peptides, dipeptides and tripeptides at ambient temperature (14 examples, 23→73 % yields) via thiols and bromoalkynes, and is chemoselective with regards to terminal alkynes. Importantly, the underexplored alkynediyl sulfide functionality incorporates a rigidifying structural element and opens new opportunities for diversification of macrocyclic frameworks through S oxidation, halide addition and azide–alkyne cycloaddition chemistries to integrate sulfones, halides or valuable fluorophores (7 examples, 37→92 % yields). 相似文献
95.
Bastien Rage Dr. Diane Delbegue Dr. Nicolas Louvain Dr. Pierre-Emmanuel Lippens 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(66):16275-16290
The amount of silicon in anode materials for Li-ion batteries is still limited by the huge volume changes during charge-discharge cycles. Such changes lead to the loss of electrical contacts, as well as mechanical and surface electrolyte interphase (SEI) instabilities, strongly reducing the cycle life. Core-shell structures have attracted a vast research interest due to the possibility of modifying some properties with a judicious choice of the shell. It is, for example, possible to improve the electronic conductivity and ionic diffusion, or buffer volume variations. This review gives a comprehensive overview of the recent developments and the different strategies used for the design, synthesis and electrochemical performance of silicon-based core-shells. It is based on a selection of the main types of silicon coatings reported in the literature, including carbon, inorganic, organic and double-layer coatings, Finally, a summary of the advantages and drawbacks of these different types of core-shells as anode materials for Li-ion batteries and some insightful suggestions in regards to their use are provided. 相似文献
96.
Bryan Guichard Philippe Cassagnau Guillaume Sudre Ren Fulchiron Bastien Ledieu Eliane Espuche 《Journal of Polymer Science.Polymer Physics》2019,57(9):535-546
High‐density polyethylene (HDPE) and nanosilica nanocomposites were prepared for SiO2 content up to 15 wt%. Microstructural characterization evidenced a homogenous distribution of silica aggregates with a mean size increasing with the filler content finally resulting in a rheological percolation between 7.5 and 10 wt%. Nanoparticles did not induce any significant impact on the matrix crystallinity but led to a real improvement on elastic properties accompanied with a large embrittlement above the percolation threshold. The effect of annealing near HDPE melting temperature was studied. Differential scanning calorimetry, X‐ray diffraction, and small‐angle X‐ray scattering analyses showed a significant change in the HDPE microstructure after annealing at 125°C. A large increase in the crystallinity (from 68 to 76%) and a clear improvement of Young's modulus (by 55%) were observed prior to polymer degradation. A valuable impact of silica particles on thermal stability was also obvious regarding the evolution of elastic properties for extended exposure times (850–1,200 h). © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019 , 57, 535–546 相似文献
97.
98.
Intramolecular hydroarylation of allenes was achieved under very mild conditions using bismuth(III) triflate as the catalyst. Efficient functionalization of activated and nonactivated aromatic nuclei led to C-C bond formation through a formal Ar-H activation. A tandem bis-hydroarylation of the allene moiety was also developed giving access to various interesting polycyclic structures. 相似文献
99.
Denicourt-Nowicki A Léger B Roucoux A 《Physical chemistry chemical physics : PCCP》2011,13(30):13510-13517
Polynitrogen ligands and/in ionic liquids (ILs) are described as a pertinent tandem to efficiently stabilize rhodium nanoparticles (NPs) in the size range of 2.0 nm for catalytic applications. Several N-donor ligands based on bipyridine skeleton were used as extra protective agents in [BMI][PF(6)] and compared in the hydrogenation of functionalized aromatic compounds at 80 °C and under 40 bar H(2). The nature of the bipyridine derivative and its influence on the coordination mode on the particle surface were proposed to explain the observed different kinetic properties. The hydrogenation of various oxygen-containing arenes was investigated and original results were described in the reduction of anisole and cresols as model lignin compounds, providing a significant ratio of ketone derivatives. A first explanation based on possible reaction routes is proposed to justify the formed products. 相似文献
100.
Vaurigaud Bastien Ture Savadkoohi Alireza Lamarque Claude-Henri 《Nonlinear dynamics》2011,66(4):763-780
In this paper, we study a Targeted Energy Transfer (TET) problem between a p degrees-of-freedom (dof) linear master structure and several coupled parallel slave Nonlinear Energy Sink (NES) systems.
In detail, each lth dof l=1,2,…,p contains n
l
parallel NES; so the linear structure has (n
1+n
2+⋅⋅⋅+n
l
+⋅⋅⋅+n
p
) NES. We are interested to study analytically the TET phenomenon during the first mode of the compound system. To this end,
complexification, averaging, and multiple scales methods are used. 相似文献