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排序方式: 共有459条查询结果,搜索用时 15 毫秒
181.
In this report, we introduced Graphene oxide‐iron oxide (GO‐Fe3O4) nanocomposites as a heterogeneous catalyst for arylation/alkylation of benzothiazoles with aldehydes and benzylic alcohols in the presence of diisopropyl azodicarboxylate (DIAD) as an oxidant which exclusively produced 2‐aryl (alkyl)‐1H–benzothizoles in moderate to excellent yields. The absence of precious metals and toxic solvent, easy product isolation, and recyclability of the GO‐Fe3O4 with no loss of activity are notable advantages of this method. 相似文献
182.
Electrochemical Synthesis of 2-(2-Chlorophenyl)-2-[(3,4- dihydroxyphenyl)(methyl)amino]cyclohexanone
Najafi M. Lajvardi M. M. Youseftabar-Miri L. Ameri M. Ghaderi O. 《Russian Journal of Electrochemistry》2018,54(12):1278-1283
Russian Journal of Electrochemistry - Electrochemical oxidation of catechol has been studied in the presence of ketamine as a drug in phosphate buffer solution mixed with ethanol using voltammetric... 相似文献
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184.
Barani Elham Lobzenko Ivan P. Korznikova Elena A. Soboleva Elvira G. Dmitriev Sergey V. Zhou Kun Marjaneh Aliakbar Moradi 《The European Physical Journal B - Condensed Matter and Complex Systems》2017,90(3):1-16
The European Physical Journal B - In this paper large resistor-capacitor (RC) networks that consist of randomly distributed conductive and capacitive elements which are much larger than those... 相似文献
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187.
Two-equation turbulence models for prediction of heat transfer on a transonic turbine blade 总被引:4,自引:0,他引:4
Two versions of the two-equation k–ω model and a shear stress transport (SST) model are used in a three-dimensional, multi-block, Navier–Stokes code to compare the detailed heat transfer measurements on a transonic turbine blade. It is found that the SST model resolves the passage vortex better on the suction side of the blade, thus yielding a better comparison with the experimental data than either of the k–ω models. However, the comparison is still deficient on the suction side of the blade. Use of the SST model does require the computation of distance from a wall, which for a multi-block grid, such as in the present case, can be complicated. However, a relatively easy fix for this problem was devised. Also addressed are issues such as (1) computation of the production term in the turbulence equations for aerodynamic applications, and (2) the relation between the computational and experimental values for the turbulence length scale, and its influence on the passage vortex on the suction side of the turbine blade. 相似文献
188.
Elham Yammine Eddy Souaid Sami Youssef Maher Abboud Stéphane Mornet Michel Nakhl Etienne Duguet 《Particle & Particle Systems Characterization》2020,37(7):2000111
The concept of patchy particles is revolutionizing the research field of colloidal assembly, by the design of particles whose surface is purposely patterned to promote attractive interactions with their neighbors in limited number, and in privileged and programmed directions. The idea of magnetic patches makes it possible to imagine assemblies not only spontaneous by simple magnetic coupling but also triggered and canceled at will due to external magnetic fields. This review shows that studies published until now mainly deal with particles with a single magnetic patch, often called Janus particles. The very diverse synthetic routes have been brought together into four main strategies, covering the size range from 100 nm to 100 µm. Their assembly capacity is described both from experimental and simulation viewpoints. The orientation of the magnetic moment of the patch and its decentering extent with respect to the particle are the key parameters for controlling the morphology of clusters, loops, staggered chains, double chains, helices, microtubes, etc. The review offers some perspectives to generalize these studies to multipatch particles, examples of which are still too rare, and to make assemblies sustainable, especially after the removal of the structuring magnetic fields. 相似文献
189.
Bi-min Zhang Newby Elham Malekzadeh Abdullah Alghunaim 《Journal of polymer science. Part A, Polymer chemistry》2020,58(19):2728-2740
This study explored the possibility of polymer interdiffusion for retaining thermoresponsive poly(N-isopropylacrylamide) (pNIPAAm) on polycarbonate (PC). It was hypothesized that interdiffusion could be facilitated either by increasing the annealing temperature or by treating PC using air plasma (AP) and ultra-violet ozone (UVO). The results showed that increasing annealing temperature only moderately improved pNIPAAm retention. Treating PC with AP led to an increase in surface-active groups and a greatly enhanced retention of pNIPAAm. UVO treatment, however, severely damaged the PC layer with no noticeable enhancement on pNIPAAm retention. The retained pNIPAAm films on PC exhibited thermoresponsive behavior as evidenced by water contact angle and desired cell attachment/detachment behaviors. These results illustrate the simplicity of using polymer interdiffusion to successfully retain pNIPAAm films on a polymer, and the resulting substrates would be less expensive and more versatile than those retained on brittle supports (e.g., glass) for applications that require resilient thermoresponsive substrates. 相似文献
190.
Dr. Elham Baktash Dr. Jérôme Capitolis Dr. Lionel Tinat Dr. Clément Larquet Dr. Tsou Hsi Camille Chan Chang Dr. Jean-Jacques Gallet Dr. Fabrice Bournel Prof. Clément Sanchez Dr. Sophie Carenco Dr. David Portehault 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(47):11114-11120
Magnéli phases TinO2n−1 (3<n≤10) are mixed Ti4+/Ti3+ oxides with high electrical conductivity. When used for water remediation or electrochemical energy storage and conversion, they are nanostructured and exposed to various environments. Therefore, understanding their surface reactivity is of prime importance. Such studies have been hindered by carbon contamination from syntheses. Herein, this synthetic and characterization challenge is addressed through a new approach to 50 nm carbon-free Ti4O7 and Ti6O11 nanoparticles. It takes advantage of the different reactivities of rutile and anatase TiO2 nanoparticles towards H2, to use the former as precursor of TinO2n−1 and the latter as a diluting agent. This approach is combined with silica templating to restrain particle growth. The surface reactivity of the Magnéli nanoparticles under different atmospheres was then evaluated quantitatively by synchrotron-radiation-based X-ray photoelectron spectroscopy, which revealed oxidized surfaces with lower conductivity than the core. This finding sheds a new light on the charge transfer occurring in these materials. 相似文献