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901.
Dr. Kai‐Yang Niu Prof. Dr. Liang Fang Rong Ye Dr. Dennis Nordlund Dr. Marca M. Doeff Prof. Dr. Feng Lin Dr. Haimei Zheng 《Angewandte Chemie (International ed. in English)》2016,55(46):14272-14276
Controlled synthesis of transition‐metal hydroxides and oxides with earth‐abundant elements have attracted significant interest because of their wide applications, for example as battery electrode materials or electrocatalysts for fuel generation. Here, we report the tuning of the structure of transition‐metal hydroxides and oxides by controlling chemical reactions using an unfocused laser to irradiate the precursor solution. A Nd:YAG laser with wavelengths of 532 nm or 1064 nm was used. The Ni2+, Mn2+, and Co2+ ion‐containing aqueous solution undergoes photo‐induced reactions and produces hollow metal‐oxide nanospheres (Ni0.18Mn0.45Co0.37Ox) or core–shell metal hydroxide nanoflowers ([Ni0.15Mn0.15Co0.7(OH)2](NO3)0.2?H2O), depending on the laser wavelengths. We propose two reaction pathways, either by photo‐induced redox reaction or hydrolysis reaction, which are responsible for the formation of distinct nanostructures. The study of photon‐induced materials growth shines light on the rational design of complex nanostructures with advanced functionalities. 相似文献
902.
904.
富铈混合稀土对AZ81合金组织与性能的影响 总被引:2,自引:0,他引:2
研究了富铈混合稀土对挤压铸造AZ81合金的显微组织和力学性能的影响。结果表明:加入不同含量富铈混合稀土的合金中都出现了一种新相Al11(Ce,La)3相,Al11(Ce,La)3相数量增多而Mg17Al12相则减少,能细化合金的组织晶粒,其细化作用在添加了1.5%富铈混合稀土的镁合金中尤为明显,但是当富铈混合稀土加入量大于2.0%时,合金中Al11(Ce,La)3相开始长大以粗大长杆状存在;在富铈混合稀土含量为1.5%时,AZ81合金的室温和150℃的综合力学性能达到最佳效果,超过2.0%时合金的室温和150℃综合力学性能开始下降;合金试样的拉伸断口带有局部韧窝的解理断裂和韧性断裂的混合特征。 相似文献
905.
In the presence of stearic acid, the surface modified Pb-Sn alloy nanoparticles were prepared through the liquid phase dispersion method in liquid paraffin. The morphologies and structures of the material were characterized by TEM, XRD, DTA and TG. The results indicate that the samples have an average diameter of 20 nm, with Pb-Sn structure and oxide shell, and have at least 12% organic covered layer. The tribology test indicates that, when the concentration of Pb-Sn alloy nanoparticles as additives in lubricating oil is between 0.25%~0.75%, the improved tribological properties are achieved. 相似文献
906.
Song Han Dr. Xin‐Bo Zhang Dr. Si‐Qi Shi Dr. Masanori Kohyama Dr. Hideaki Tanaka Dr. Nobuhiro Kuriyama Dr. Naoki Taoka Dr. Teruo Kaneko Dr. Qiang Xu Prof. 《Chemphyschem》2008,9(11):1564-1569
Density functional theory calculations are carried out to study CO adsorption on the (001) surface of a LaNi5 hydrogen storage alloy. At low coverages, CO favors adsorption on Ni? Ni bridge sites. With an increase in CO coverage, the decrease in the adsorption energy is much larger for Ni? Ni? CO bridge adsorption than that for Ni? CO on‐top adsorption. Thus, the latter sites in the relatively stable adsorption structure are preferentially utilized at high CO coverages. The nature of the bonding between CO and the LaNi5 (001) surface is analyzed in detail. 相似文献
907.
Processes of electrochemical oxidation of Pd-rich Pd–Ni alloys in basic solutions were studied with the aim of electrochemical
quartz crystal microbalance. Potentials of current peaks of Ni(II)/Ni(III) redox couple are independent of alloy composition.
On the other hand, Ni(II)/Ni(III) redox couples formed on Pd–Ni alloys and Ni differ in respect to the structure of involved
compounds and the processes of transport of the species accompanying oxidation/reduction reaction. The process of oxidation
of Pd exhibits some differences between pure Pd and Pd–Ni alloys. This concerns mainly on participation of adsorbed water/OH− in Pd oxidation process. In the initial stages of Pd oxidation, the source of oxygen is water/OH− from the bulk of the solution. At this stage of the process, the product of Pd oxidation could be described as Pd(OH)2 or PdOH2O. With further progress in oxidation process, adsorbed species, water/OH−, start to play a decisive role. Hydrous species, i.e. Pd(OH)2 or PdOH2O, are also reduced in the final stages of Pd(II) reduction process.
This study is dedicated to the 70th birthday of Professor Oleg Petrii. 相似文献
908.
S. Michel S. Diliberto N. Stein B. Bolle C. Boulanger 《Journal of Solid State Electrochemistry》2008,12(1):95-101
Composition modulated Bi2(Te1−xSex)3 thin films were prepared on stainless steel substrates by cathodic electrodeposition. The composition was dependent on the
deposition conditions. It was possible to obtain, in the same electrolyte, films with either an excess or a deficiency of
bismuth in relation to stoichiometric Bi2(Te0.9Se0.1)3 by changing the deposition potential or the applied current density. The excess of bismuth was reached at the highest cathodic
conditions. The variation of the crystallographic axis and the morphology with a granular structure were correlated with the
presence of the Bi enrichment in the ternary. The crystallographic texture of bismuth telluride films was studied according
to the electrodeposition conditions. The films presented a fibre texture, and a main orientation {11.0} was observed. Electrical
and thermoelectric properties of a Bi1.98Te2.67Se0.39 film were measured and showed an n-type behaviour. 相似文献
909.
Copper-nickel bimetallic nanoparticles decorated on carboxylated multi-walled carbon nanotubes (Cu/Ni/CMWCNTs)were prepared by using a simple one-pot solvothermal method,which was then employed to construct a highly sensitive non-enzymatic glucose sensor. The modified electrode showed high sensitivity and stability in glucose detection,which was mainly attributed to the synergistic effect of the compact copper-nickel nanocomposite and carboxylated multi-walled carbon nanotubes that possessing high specific surface area to increase the number of active sites and to improve the electrocatalytic activity of the modified electrode. The phase structure and morphology of the material were characterized by X-ray diffraction and scanning electron microscope; the electrochemical performance of the sensor was studied by cyclic voltammetry and chronoamperometry. The sensor had a sensitivity of 1949.1 μµA·L/(mmol·cm2)for glucose detection in the linear range of 1.0-8000 μµmol/L at a potential of 0.55 V,and the detection limit was 0.2 μµmol/L. The sensor was also applied to measure the concentration of glucose in serum samples. The developed nanocomposites sensor has the potential prospect to monitor blood glucose. © 2023, Youke Publishing Co.,Ltd. All rights reserved. 相似文献
910.
Yan Gao Rui Xiao Shangbiao Zhang Dr. Yanan Wang Dr. Zheliang Yuan 《European journal of organic chemistry》2023,26(38):e202300668
Due to their high lipophilicity and strong electron-withdrawing property, more and more attention has been paid to introducing trifluoromethylseleno and fluoroalkylseleno moieties into organic molecules. In this short review, we categorize the synthesis of compounds that combine selenium and fluorinated moieties into two main types: trifluoromethylselenolation (CF3Se) and fluoroalkylselenolation (RfSe, except CF3Se). This review aims to provide a summary of the recent advances in direct C−H trifluoromethylselenolation and fluoroalkylselenolation from the synthesis of trifluoromethylselenolation and fluoroalkylselenolation reagents to their application. Based on the method of how the RfSe group was introduced, the main content is divided into three parts: transition-metal-free reactions, transition-metal-mediated/catalyzed reactions and photo-catalyzed reactions. The general substrate scope, mechanism and limitations would also be discussed so that we hope the review will serve as an inspiration for further research in this appealing research field. 相似文献