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91.
Unravelling the Correlation between the Aspect Ratio of Nanotubular Structures and Their Electrochemical Performance To Achieve High‐Rate and Long‐Life Lithium‐Ion Batteries 下载免费PDF全文
Dr. Yuxin Tang Dr. Yanyan Zhang Jiyang Deng Dr. Dianpeng Qi Wan Ru Leow Jiaqi Wei Dr. Shengyan Yin Prof. Zhili Dong Prof. Rachid Yazami Prof. Zhong Chen Prof. Xiaodong Chen 《Angewandte Chemie (International ed. in English)》2014,53(49):13488-13492
The fundamental understanding of the relationship between the nanostructure of an electrode and its electrochemical performance is crucial for achieving high‐performance lithium‐ion batteries (LIBs). In this work, the relationship between the nanotubular aspect ratio and electrochemical performance of LIBs is elucidated for the first time. The stirring hydrothermal method was used to control the aspect ratio of viscous titanate nanotubes, which were used to fabricate additive‐free TiO2‐based electrode materials. We found that the battery performance at high charging/discharging rates is dramatically boosted when the aspect ratio is increased, due to the optimization of electronic/ionic transport properties within the electrode materials. The proof‐of‐concept LIBs comprising nanotubes with an aspect ratio of 265 can retain more than 86 % of their initial capacity over 6000 cycles at a high rate of 30 C. Such devices with supercapacitor‐like rate performance and battery‐like capacity herald a new paradigm for energy storage systems. 相似文献
92.
Benzocycloheptapyrimidines are an important class of compounds because of their pharmacological properties. We report here two new synthetic procedures for the preparation of 2,4-dialkylamino substituted benzocycloheptapyrimidines. One of these methods is based on the reaction of substituted cyanamides with the vinyl triflate of the 1-benzosuberone while the other preparation relies on the nucleophilic displacement of methylsulfonyl groups by secondary amines at the 2 and 4 positions of benzocycloheptapyrimidine intermediates. 相似文献
93.
Metallation-ribosylation of 2-bromothiophene 1 when conducted at room temperature afforded the original glycosylated dibromothiophene 3b following a regiocontrolled halogen transfer-based halogen-dance process. Then, stereocontrolled reduction-cyclization of hemiacetals 3a-c allowed straightforward access to the halogenated thiophenyl-C-nucleosides 6a-c. 相似文献
94.
Bhiri F Chaabouni SE Limam F Ghrir R Marzouki N 《Applied biochemistry and biotechnology》2008,149(2):169-182
The Pol6 mutant of Penicillium occitanis fungus is of great biotechnological interest since it possesses a high capacity of cellulases and β-glucosidase production
with high cellulose degradation efficiency (Jain et al., Enzyme Microb Technol, 12:691–696, 1990; Hadj-Taieb et al., Appl Microbiol Biotechnol, 37:197–201, 1992; Ellouz Chaabouni et al., Enzyme Microb Technol, 16:538–542, 1994; Ellouz Chaabouni et al., Appl Microbiol Biotechnol, 43:267–269, 1995). In this work, two forms of β-glucosidase (β-glu 1 and β-glu 2) were purified from the culture supernatant
of the Pol6 strain by gel filtration, ion exchange chromatography, and preparative anionic native electrophoresis. These enzymes
were eluted as two distinct species from the diethylamino ethanol Sepharose CL6B and anionic native electrophoresis. However,
both behaved identically on sodium dodecyl sulfate polyacrylamide gel electrophoresis (MW, 98 kDa), shared the same amino
acid composition, carbohydrate content (8%), and kinetic properties. Moreover, they strongly cross-reacted immunologically.
They were active on cellobiose and pNPG with Km values of 1.43 and 0.37 mM, respectively. β-glu 1 and β-glu 2 were competitively inhibited by 1 mM of glucose and 0.03 mM
of δ-gluconolactone. They were also significantly inhibited by Hg2+ and Cu2 at 2 mM. The addition of purified enzymes to the poor β-glucosidase crude extract of Trichoderma reesei increased its hydrolytic efficiency on H3P04 swollen cellulose but had no effect with P. occitanis crude extract. Besides their hydrolytic activities, β-glu 1 and β-glu 2 were endowed with trans-glycosidase activity at high
concentration of glucose. 相似文献
95.
Safia Djedri Rachid Issaadi Luc Picton Nadji Moulai-Mostefa 《Journal of Dispersion Science and Technology》2013,34(7):877-882
Surfactant synthesis was realized from Algerian crude oil and petroleum fractions. To predict the composition (wt%) in paraffins, naphtenes, and aromatics, the crude oil and petroleum fractions were first characterized using the n-d-PA empirical method of Robert. The characterization showed a good level in aromatics compounds which give high yield in the sulfonation reaction by oleum. The synthesized surfactants were characterized by spectroscopic techniques (UV, FTIR) and by critical micelle concentration (CMC), Krafft temperature, solubility (in aqueous and in salt solution), molecular weight, and matter actives (%) measurements. The formulation of microemulsion using synthesized surfactant from plat format petroleum fraction showed a Winsor III type system. The effect of salinity demonstrates the existence of an optimal value of NaCl concentration for which the interfacial tension takes the lowered value (10?4 mN/m). Viscosity measurements confirm that the formulated microemulsion has a Newtonian behavior. 相似文献
96.
Ghanem A Bados P Perreau F Benabdallah R Plagellat C de Alencastro LF Einhorn J 《Analytical and bioanalytical chemistry》2008,391(1):345-352
A multiresidue method has been developed to analyze atrazine (ATZ), diuron (DIU), and their major degradation products, desethylatrazine
(DEA), desisopropylatrazine (DIA), and dichlorophenylmethylurea in sewage sludge. Liquid chromatography coupled to electrospray
tandem mass spectrometry (LC–ESI-MS–MS) allowed, in the multiple-reaction monitoring mode, the simultaneous analysis of these
pesticides in only one run after their extraction with ethyl acetate–dichloromethane 90:10 (v/v) and a cleanup on a Florisil column. Stable isotopically labeled ATZ and DIU were used as internal standards to overcome
matrix effects during the pesticide quantification. Using fortified samples, the method gave rise to 86–115% as mean recovery
values depending on the analyte. Limits of detection (LODs) and of quantification (LOQs) ranging from 0.3 (DIA) to 1.5 (DEA)
μg kg−1 dw and from 0.4 (DIA) to 2.0 (DEA) μg kg−1 dw, respectively, were sufficient to achieve the monitoring of these molecules in sludge from wastewater treatment plants
of the Ile-de-France region. 相似文献
97.
Mohammed Kara Amine Assouguem Omkulthom Mohamed Al kamaly Safa Benmessaoud Hamada Imtara Hamza Mechchate Christophe Hano Abdou Rachid Zerhouni Jamila Bahhou 《Molecules (Basel, Switzerland)》2021,26(18)
Apple vinegar is a natural product widely used in food and traditional medicine as it contains many bioactive compounds. The apple variety and production methods are two factors that play a major role in determining the quality of vinegar. Therefore, this study aims to determine the quality of apple vinegar samples from different varieties (Red Delicious, Gala, Golden Delicious, and Starking Delicious) prepared by three methods using small apple pieces, apple juice, and crushed apple, through determining the physicochemical properties and antibacterial activity of these samples. The antibacterial activity was studied against five pathogenic bacteria: Staphylococcus aureus, Klebsiella pneumonia, Escherichia coli (ATB: 57), Escherichia coli (ATB: 97), and Pseudomonas aeruginosa, using two methods, disk diffusion and microdilution, for determining the minimum inhibitory concentrations and the minimum bactericidal concentrations. The results of this study showed that the lowest pH value was 3.6 for Stark Delicious, obtained by liquid fermentation, and the highest acetic acid values were 4.7 and 4% for the vinegar of Red Delicious and Golden Delicious, prepared by solid fermentation, respectively. The results of the antibacterial activity showed considerable activity of apple vinegar on the tested strains. Generally, the Staphylococcus aureus strain appears less sensitive and Pseudomonas aeruginosa seems to be very sensitive against all samples, while the other strains have distinct sensitivities depending on the variety studied and the method used. A higher antibacterial activity was found in vinegar obtained by the apple pieces method and the Red Delicious variety, with a low MIC and MBC recorded, at 1.95 and 3.90 µL/mL, respectively. This study has shown that the choice of both apple variety and production method is therefore an essential step in determining and aiming for the desired quality of apple vinegar. 相似文献
98.
Pham Sy Hieu Pham Minh Doan Sane Abdoul Razac Nguyen Xuan Hoan Semlal Nawal Boulif Rachid Germeau Alain Toussaint Claudia Sharrock Patrick Nzihou Ange 《Journal of Thermal Analysis and Calorimetry》2021,146(5):2027-2033
Journal of Thermal Analysis and Calorimetry - Up-to-date, solar salt (a mixture of 60 mass% NaNO3 and 40 mass% KNO3) is practically the only media for thermal energy storage (TES) in concentrated... 相似文献
99.
The one-pot reaction of 1-benzylpiperidin-4-one with different nitriles in the presence of triflic anhydride affords substituted tetrahydropyrido[4,3-d]pyrimidines. Reaction with methylthiocyanate forms the corresponding methylthio substituted tetrahydropyridopyrimidines which can be easily converted into dimethoxy and dicarbonyl derivatives. 相似文献
100.
Abdelbaki?AttiouiEmail author Rachid?Choukri 《Mediterranean Journal of Mathematics》2004,1(3):367-374
We show that a locally convex algebra is topologically algebraic if, and only if, it is algebraic.Thanks are offered to Professor M. Oudadess for many remarks which allowed an improvement of the first version of this paper. We are also indebted to Professor A. Mallios for valuable suggestions. 相似文献