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排序方式: 共有1684条查询结果,搜索用时 15 毫秒
1.
Dr. Silvia Castro-Fernández Carlos M. Cruz Dr. Inês F. A. Mariz Dr. Irene R. Márquez Vicente G. Jiménez Lucía Palomino-Ruiz Prof. Juan M. Cuerva Dr. Ermelinda Maçôas Dr. Araceli G. Campaña 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(18):7205-7211
A new family of distorted ribbon-shaped nanographenes was designed, synthesized, and their optical and electrochemical properties were evaluated, pointing out an unprecedented correlation between their structural characteristics and the two-photon absorption (TPA) responses and electrochemical band gaps. Three nanographene ribbons have been prepared: a seven-membered-ring-containing nanographene presenting a tropone moiety at the edge, its full-carbon analogue, and a purely hexagonal one. We have found that the TPA cross-sections and the electrochemical band gaps of the seven-membered-ring-containing compounds are higher and lower, respectively, than those of the fully hexagonal polycyclic aromatic hydrocarbon (PAH). Interestingly, the inclusion of additional curvature has a positive effect in terms of non-linear optical properties of those ribbons. 相似文献
2.
Hoang Luc Nguyen Huy Tuan Nguyen Yong Zhou 《Mathematical Methods in the Applied Sciences》2019,42(10):3481-3495
In this paper, we deal with the backward problem of determining initial condition for Rayleigh‐Stokes where the data are given at a fixed time. The problem has many applications in some non‐Newtonian fluids. We give some regularity properties of the solution to backward problem. 相似文献
3.
Zihua Guo Xingxing Liu Luc Molinet Zhaoyang Yin 《Journal of Differential Equations》2019,266(2-3):1698-1707
We prove norm inflation and hence ill-posedness for a class of shallow water wave equations, such as the Camassa–Holm equation, Degasperis–Procesi equation and Novikov equation etc., in the critical Sobolev space and even in the Besov space for . Our results cover both real-line and torus cases (only real-line case for Novikov), solving an open problem left in the previous works ([5], [14], [16]). 相似文献
4.
Fran?ois?NicotEmail author Luc?Sibille Pierre-Yves?Hicher 《Continuum Mechanics and Thermodynamics》2015,27(1-2):173-193
When granular materials are subjected to proportional strain loading paths, they manifest a variety of behaviors depending on the initial void ratio of the specimen as well as the imposed dilatancy/contractancy rate. In some cases, the stress components may vanish over the duration of the test, and the specimen may progressively liquefy. To investigate this behavior, the authors have developed a kinematic approach to be deployed in two parts. First, numerical simulations are performed by means of a discrete element method. Secondly, two micromechanical models have corroborated the DEM results. The performance of these models may explain a number of microstructural mechanisms responsible for the macroscopic constitutive behavior. 相似文献
5.
Electronic Structure Modulation in an Exceptionally Stable Non‐Heme Nitrosyl Iron(II) Spin‐Crossover Complex 下载免费PDF全文
Lucía Piñeiro‐López Dr. Norma Ortega‐Villar Prof. Dr. M. Carmen Muñoz Dr. Gábor Molnár Dr. Jordi Cirera Prof. Dr. Rafael Moreno‐Esparza Prof. Dr. Víctor M. Ugalde‐Saldívar Dr. Azzedine Bousseksou Prof. Dr. Eliseo Ruiz Prof. Dr. José A. Real 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(36):12741-12751
The highly stable nitrosyl iron(II) mononuclear complex [Fe(bztpen)(NO)](PF6)2 (bztpen=N‐benzyl‐N,N′,N′‐tris(2‐pyridylmethyl)ethylenediamine) displays an S=1/2?S=3/2 spin crossover (SCO) behavior (T1/2=370 K, ΔH=12.48 kJ mol?1, ΔS=33 J K?1 mol?1) stemming from strong magnetic coupling between the NO radical (S=1/2) and thermally interconverted (S=0?S=2) ferrous spin states. The crystal structure of this robust complex has been investigated in the temperature range 120–420 K affording a detailed picture of how the electronic distribution of the t2g–eg orbitals modulates the structure of the {FeNO}7 bond, providing valuable magneto–structural and spectroscopic correlations and DFT analysis. 相似文献
6.
Letters in Mathematical Physics - We characterize quantum perfect state transfer on real-weighted graphs of the Johnson scheme $${\mathcal {J}}(n,k)$$ , which represent spin networks with... 相似文献
7.
Charlotte Menager Nathanaël Guigo Luc Vincent Nicolas Sbirrazzuoli 《Journal of polymer science. Part A, Polymer chemistry》2020,58(12):1717-1727
The curing of epoxidized linseed oil (ELO) with three different bio-based dicarboxylic acids (sebacic acid, suberic acid, and succinic acid) has been investigated. No accelerators or catalysts were used and the resulting thermosets are 100% bio-based. Structural investigations of the three crosslinked ELO resins were made using FTIR spectroscopy and TMA, that is, tensile tests, TGA, and DMA. As evidenced by FTIR measurements ELO and dicarboxylic acids reacts but no major differences can be distinguished between the dicarboxylic acids. Non-isothermal curing has been conducted by rheological and DSC measurements. Advanced isoconversional analysis applied to DSC data in association with the complex viscosity variations gives new insights into the polymerization mechanism. The length of dicarboxylic acid carbon chain modifies the reaction rate. Then, a correlation between reaction rate, activation energy, pre-exponential factors, polymerization mechanism, and change in rate-limiting step was shown. DMA and tensile tests highlight the relationship between the carbon chain length, reactivity, and thermomechanical properties. The use of succinic acid allows reaching a higher Tg and thermal stability. 相似文献
8.
Tania Merhi Alban Jonchère Dr. Luc Girard Dr. Olivier Diat Miquel Nuez Prof. Clara Viñas Dr. Pierre Bauduin 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(61):13935-13947
Metalla-bis-dicarbollides, such as the cobalta-bis-dicarbollide (COSAN) anion [Co(C2B9H11)2]−, have attracted much attention in biology but a deep understanding of their interactions with cell components is still missing. For this purpose, we studied the interactions of COSAN with the glucose moiety, which is ubiquitous at biological interfaces. Octyl-glucopyranoside surfactant (C8G1) was chosen as a model as it self-assembles in water and creates a hydrated glucose-covered interface. At low COSAN content and below the critical micellar concentration (CMC) of C8G1, COSAN binds to C8G1 monomers through the hydrophobic effect. Above the CMC of C8G1, COSAN adsorbs onto C8G1 micelles through the superchaotropic effect. At high COSAN concentrations, COSAN disrupts C8G1 micelles and the assemblies become similar to COSAN micelles but with a small amount of solubilized C8G1. Therefore, COSAN binds in a versatile way to C8G1 through either the hydrophobic or superchaotropic effect depending on their relative concentrations. 相似文献
9.
10.
Lucía Vizcaíno-Anaya Dr. Carlos Herreros-Lucas Dr. José M. Vila-Fungueiriño Dr. María del Carmen Giménez-López 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(67):e202201861
Magnetic hyperthermia (MH) shows great potential in clinical applications because of its very localized action and minimal side effects. Because of their high saturation magnetization values, reduced forms of iron are promising candidates for MH. However, they must be protected in order to overcome their toxicity and instability (i. e., oxidation) under biological conditions. In this work, a novel methodology for the protection of iron nanoparticles through confinement within graphitic carbon layers after thermal treatment of preformed nanoparticles supported on carbon is reported. We demonstrate that the size and composition of the nascent confined iron nanoparticles, as well as the thickness of their protective carbon layer can be controlled by selecting the nature of the carbon support. Our findings reveal that a higher nanoparticle–carbon interaction, mediated by the presence of oxygen-containing groups, induces the formation of small and well-protected α-Fe-based nanoparticles that exhibit promising results towards MH based on their enhanced specific absorption rate values. 相似文献