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131.
Mortar physical properties evolution in extrusion flow 总被引:1,自引:0,他引:1
Arnaud Perrot Christophe Lanos Yannick Melinge Patrice Estellé 《Rheologica Acta》2007,46(8):1065-1073
Extrusion is not a common way to form firm cement-based material. Due to material frictional behaviour, drainage phenomenon
appears and leads to process blockage. The properties of the extrusion multiphase flow of such specific materials have to
be highlighted to understand the properties of the process flow. An extrudible mortar is formulated according to extrusion
criteria provided by literature tests developed to describe the evolution of the paste undergoing extrusion. To study the
relationship between flow properties, extrusion force and material consolidation, a technique based on the measurement of
paste hardness in the billet zone is developed. Measurements of the local paste density and flow visualisation are also performed.
Results show that in the range of used ram velocities, filtration occurs between fluid and solid phases. This creates zones
of preferential flow and of non-flowing consolidated material.
Paper presented at the 3rd Annual European Rheology Conference held on April 27–29, 2006, Crete, Greece. 相似文献
132.
Suppliers network in the global context under price discounts and uncertain fluctuations of currency exchange rates have become critical in today’s world economy. We study the problem of suppliers’ selection in the presence of uncertain fluctuations of currency exchange rates and price discounts. We specifically consider a buyer with multiple sites sourcing a product from heterogeneous suppliers and address both the supplier selection and purchased quantity decision. Suppliers are located worldwide and pricing is offered in suppliers’ local currencies. Exchange rates from the local currencies of suppliers to the standard currency of the buyer are subject to uncertain fluctuations overtime. In addition, suppliers offer discounts as a function of the total quantity bought by the different customer’ sites over the time horizon irrespective of the quantity purchased by each site. 相似文献
133.
Renaud Dufour Guillaume Perry Maxime Harnois Yannick Coffinier Vincent Thomy Vincent Senez Rabah Boukherroub 《Colloid and polymer science》2013,291(2):409-415
The paper reports on the wetting characterization of two surfaces presenting reentrant shapes at micro- and nanoscale using low surface tension liquids (down to 28 mN/m). On the one hand, mushroom-like microstructures are fabricated by molding poly(dimethylsiloxane) (PDMS) onto a patterned sacrificial photoresist bilayer. On the other hand, zinc oxide nanostructures (ZnO NS) are synthesized by easy and fast chemical bath deposition technique. The PDMS and ZnO NS surfaces are then chemically modified with 1H,1H,2H,2H-perfluorodecyltrichlorosilane in vapor phase. Both PDMS and ZnO NS surfaces exhibit a large apparent contact angle (>150°) and contact angle hysteresis varying from 50° to a quasi-null value. This large discrepancy can be ascribed to the length scale and topography of the structures, promoting either a vertical imbibition or a lateral spreading within the roughness. 相似文献
134.
This article presents a novel III‐V on silicon laser. This work exploits the phenomenon that a passive silicon cavity, side‐coupled to a III‐V waveguide, will provide high and narrow‐band reflectivity into the III‐V waveguide: the resonant mirror. This results in an electrically pumped laser with a threshold current of 4 mA and a side‐mode suppression ratio up to 48 dB.
135.
136.
Jonathan Mendy Dr. Anh Thy Bui Dr. Amandine Roux Jean-Christophe Mulatier Damien Curton Dr. Alain Duperray Dr. Alexei Grichine Dr. Yannick Guyot Dr. Sophie Brasselet Dr. François Riobé Dr. Chantal Andraud Dr. Boris Le Guennic Dr. Véronique Patinec Pr. Raphael Tripier Dr. Maryline Beyler Dr. Olivier Maury 《Chemphyschem》2020,21(10):1036-1043
Cationic lanthanide complexes are generally able to spontaneously internalize into living cells. Following our previous works based on a diMe-cyclen framework, a second generation of cationic water-soluble lanthanide complexes based on a constrained cross-bridged cyclam macrocycle functionalized with donor-π-conjugated picolinate antennas was prepared with europium(III) and ytterbium(III). Their spectroscopic properties were thoroughly investigated in various solvents and rationalized with the help of DFT calculations. A significant improvement was observed in the case of the Eu3+ complex, while the Yb3+ analogue conserved photophysical properties in aqueous solvent. Two-photon (2P) microscopy imaging experiments on living T24 human cancer cells confirmed the spontaneous internalization of the probes and images with good signal-to-noise ratio were obtained in the classic NIR-to-visible configuration with the Eu3+ luminescent bioprobe and in the NIR-to-NIR with the Yb3+ one. 相似文献
137.
Xin Li Therese B. Brennan Cian Kingston Yannick Ortin Patrick J. Guiry 《Molecules (Basel, Switzerland)》2022,27(18)
Herein, we report the design and synthesis of a series of chiral pyrrolidine-substituted ferrocene-derived ligands. The proficiency of this novel structural motif was demonstrated in the Rh-catalyzed asymmetric hydrogenation of dehydroamino acid esters and α-aryl enamides. The products were obtained with full conversions and excellent levels of enantioselectivities of up to >99.9% ee and 97.7% ee, respectively, using a BINOL-substituted phosphine-phosphoaramidite ligand which possesses planar, central, and axial chirality elements. 相似文献
138.
Chunhui He Dr. Qian Zhang Yinqi Fan Prof. Cezhou Zhao Dr. Chun Zhao Jingyao Ye Dr. Yannick J. Dappe Prof. Richard J. Nichols Prof. Li Yang 《Chemphyschem》2019,20(14):1830-1836
A combined experimental and theoretical study on molecular junctions with asymmetry in both the electrode type and in the anchoring group type is presented. A scanning tunnelling microscope is used to create the “asymmetric” Au-S-(CH2)n-COOH-graphene molecular junctions and determine their conductance. The measurements are combined with electron transport calculations based on density functional theory (DFT) to analyze the electrical conductance and its length attenuation factor from a series of junctions of different molecular length (n). These results show an unexpected trend with a rather high conductance and a smaller attenuation factor for the Au-S-(CH2)n-COOH-graphene configuration compared to the equivalent junction with the “symmetrical” COOH contacting using the HOOC-(CH2)n-COOH series. Owing to the effect of the graphene electrode, the attenuation factor is also smaller than the one obtained for Au/Au electrodes. These results are interpreted through the relative molecule/electrode couplings and molecular level alignments as determined with DFT calculations. In an asymmetric junction, the electrical current flows through the less resistive conductance channel, similarly to what is observed in the macroscopic regime. 相似文献
139.
Dr. María Rodríguez‐Castillo Gustavo Lugo‐Preciado Dr. Danielle Laurencin Dr. Frederik Tielens Dr. Arie van der Lee Dr. Sébastien Clément Dr. Yannick Guari Dr. José M. López‐de‐Luzuriaga Dr. Miguel Monge Dr. Françoise Remacle Dr. Sébastien Richeter 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(30):10446-10458
The reactivity of benzimidazol‐2‐ylidenes with respect to gold nanoparticles (AuNPs) has been investigated using a combined experimental and computational approach. First, the grafting of benzimidazol‐2‐ylidenes bearing benzyl groups on the nitrogen atoms is described, and comparisons are made with structurally similar N‐heterocyclic carbenes (NHCs) bearing other N‐groups. Similar reactivity was observed for all NHCs, with 1) the erosion of the AuNPs under the effect of the NHC and 2) the formation of bis(NHC) gold complexes. DFT calculations were performed to investigate the modes of grafting of such ligands, to determine adsorption energies, and to rationalize the spectroscopic data. Two types of computational models were developed to describe the grafting onto large or small AuNPs, with either periodic or cluster‐type DFT calculations. Calculations of NMR parameters were performed on some of these models, and discussed in light of the experimental data. 相似文献
140.