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1.
Adeniyi Adebayo A. Akintayo Cecilia O. Akintayo Emmanuel T. Conradie Jeanet 《Structural chemistry》2020,31(3):861-875
Structural Chemistry - Natural-based polyols are seen by polyurethane industries as an alternative to the petroleum-based polyols because of increasing challenges due to the oil crisis and global... 相似文献
2.
Kevin Grollier Alexis Taponard Clément Ghiazza Emmanuel Magnier Thierry Billard 《Helvetica chimica acta》2020,103(11):e2000185
α-Trifluoromethylselenolated enones constitute valuable building-blocks for further synthesis of innovative fluorinated compounds. Herein, we described an easy access to such compounds in green conditions through a Morita-Baylis-Hillman like reaction. These conditions have also been extended to higher fluorinated homologs. 相似文献
3.
João Marcos G. Barbosa Milenna K. Fernandes Rodrigues Lurian C. David Taynara C. e Silva Danielly A. Fortuna Lima Naiara Z. Pereira Emmanuel B. D'Alessandro Anselmo E. de Oliveira Paulo H. Jorge da Cunha Maria Clorinda S. Fioravanti Nelson R. Antoniosi Filho 《Biomedical chromatography : BMC》2020,34(11):e4935
An innovative volatolomic approach employs the detection of biomarkers present in cerumen (earwax) to identify cattle intoxication by Stryphnodendron rotundifolium Mart., Fabaceae (popularly known as barbatimão). S. rotundifolium is a poisonous plant with the toxic compound undefined and widely distributed throughout the Brazilian territory. Cerumen samples from cattle of two local Brazilian breeds (‘Curraleiro Pé-Duro’ and ‘Pantaneiro’) were collected during an experimental intoxication protocol and analyzed using headspace (HS)/GC–MS followed by multivariate analysis (genetic algorithm for a partial least squares, cluster analysis, and classification and regression trees). A total of 106 volatile organic metabolites were identified in the cerumen samples of bovines. The intoxication by S. rotundifolium influenced the cerumen volatolomic profile of the bovines throughout the intoxication protocol. In this way, it was possible to detect biomarkers for cattle intoxication. Among the biomarkers, 2-octyldecanol and 9-tetradecen-1-ol were able to discriminate all samples between intoxicated and nonintoxicated bovines. The cattle intoxication diagnosis by S. rotundifolium was accomplished by applying the cerumen analysis using HS/GC–MS, in an easy, accurate, and noninvasive way. Thus, the proposed bioanalytical chromatography protocol is a useful tool in veterinary applications to determine this kind of intoxication. 相似文献
4.
“(Diphosphine)Nickel”‐Catalyzed Negishi Cross‐Coupling: An Experimental and Theoretical Study 下载免费PDF全文
Dr. Emmanuel Nicolas Alexia Ohleier Florian D'Accriscio Dr. Anne‐Frédérique Pécharman Dr. Matthieu Demange Dr. Philippe Ribagnac Dr. Jorge Ballester Dr. Corinne Gosmini Dr. Nicolas Mézailles 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(21):7690-7694
The use of a strongly donating “(bis‐dialkylphosphine)Ni” fragment promotes the catalytic coupling of a large range of ArCl and ArZnCl derivatives under mild conditions. Stoichiometric mechanistic investigations and DFT calculations prove that a Ni0/NiII cycle is operative in this system. 相似文献
5.
Florence Drui Emmanuel Franck Philippe Helluy Laurent Navoret 《Comptes Rendus Mecanique》2019,347(3):259-269
The over-relaxation approach is an alternative to the Jin–Xin relaxation method in order to apply the equilibrium source term in a more precise way. This is also a key ingredient of the lattice Boltzmann method for achieving second-order accuracy. In this work, we provide an analysis of the over-relaxation kinetic scheme. We compute its equivalent equation, which is particularly useful for devising stable boundary conditions for the hidden kinetic variables. 相似文献
6.
Caterina Calgaro Claire Colin Emmanuel Creus Ezzeddine Zahrouni 《Mathematical Methods in the Applied Sciences》2019,42(1):250-271
In this work, we prove the existence and the uniqueness of the strong solution of a low‐Mach model, for which the dynamic viscosity of the fluid is a given function of its temperature. The method is based on the convergence study of a sequence towards the solution, for which the rates are also given. The originality of the approach is to consider the system in terms of the temperature and the velocity, leading to a nonlinear temperature equation and the development of some specific tools and results. 相似文献
7.
Jesús Emmanuel Solís‐Prez Jos Francisco Gmez‐Aguilar Lizeth Torres Ricardo Fabricio Escobar‐Jimnez Juan Reyes‐Reyes 《Mathematical Methods in the Applied Sciences》2019,42(18):7335-7348
In this work, the design of spectral observers for signal reconstruction based on Kalman filters is performed and evaluated. The conformable derivative and the beta‐derivative were used to design the Kalman filters. Both derivatives satisfy the same formulas of the classical derivation, eg, the chain rule. The derivative order, the Ricatti equation parameters, and the observers tuning parameters were optimized using an optimization algorithm based on the bat's echolocation behavior (Bat algorithm). The simulation results showed the advantages of using the proposed observers for the signal reconstruction. 相似文献
8.
Dr. Wei Zhang Dr. Emmanuel Baudouin Marie Cordier Dr. Gilles Frison Dr. Bastien Nay 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(36):8643-8648
A one-pot methodology to synthesize metastable bicyclic 2,5-dihydrooxepines from cyclic 1,3-diketones and 1,4-dibromo-2-butenes through the retro-Claisen rearrangement of syn-2-vinylcyclopropyl diketone intermediates is reported. DFT calculations were performed to understand the reaction selectivity and mechanisms towards [1,3]- or [3,3]-sigmatropic rearrangements, highlighting the crucial influence of the temperature. The reaction was successfully applied to a short protecting group-free total synthesis of radulanin A, a natural 2,5-dihydrobenzoxepine. Moreover, the strong herbicidal potential of this natural product is demonstrated for the first time. 相似文献
9.
We study the mechanical response, and tearing features of crêpe paper, a two-dimensional, very anisotropic material, with one direction much less stiff than the other one. Depending on how the soft direction has been pre-stretched or not, the apparent Young modulus of the material can be varied over a broad range, while its fracture energy remains unaltered. The classical tearing concertina problem shows that a macroscopic measurement (the shape of the teared region) provides a direct access to the fracture properties of the material (effective Young's modulus, and fracture energy). The overall discussion is conducted in the frame of Griffith's theory of fracture. 相似文献
10.
Sharmaine B. Luk Adrien Métafiot Judith Morize Emmanuel Edeh Milan Marić 《Journal of polymer science. Part A, Polymer chemistry》2021,59(19):2140-2153
Ambient pressure chemical hydrogenation using p-toluene sulfonyl hydrazide (TSH) via thermal diimide formation (N2H2) permitted reduction of double bonds of poly(myrcene) (poly[Myr]) and poly(farnesene) (poly[Far]). Both pendent and backbone double bonds in poly(Myr) (Mn = 56 kg/mol) and poly(Far) (Mn = 62 kg/mol) synthesized by conventional free radical polymerization were hydrogenated to almost completion. Furthermore, TSH semi-batch addition efficiently hydrogenated double bonds, while avoiding undesired autohydrogenation of diimides that occurred in batch mode. Thermal stability improved for hydrogenated poly(Myr) and poly(Far), where temperature at 10% weight loss (T10%) increased from 188 to 404°C for poly(Myr) and from 310 to 379°C for poly(Far). Tgs of poly(Myr) and poly(Far) also increased by about 10–25°C, indicating increased stiffness after hydrogenation. Finally, viscosities of poly(Myr) and poly(Far) were also increased after hydrogenation, and a greater increase was observed for poly(Myr) (by two orders of magnitude from 102 to 104 Pa s) due to its Mn being much higher than its entanglement molecular weight. Poly(Far) viscosity only increased by 1.5 times after hydrogenation (~104 Pa s), comparable to the poly(Myr) after hydrogenation, suggesting unsaturated poly(Far) was more entangled than unsaturated poly(Myr) because of its longer side chains. 相似文献