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101.
Mashhour Alali Bani-Ata 《代数通讯》2013,41(7):2439-2443
The aim of this article is to investigate all semifields A of order q 4 where q is a power of 2, having the properties that A contains GF(q 2) in its left nucleus and admits a four-group E ? Z 2 × Z 2 of automorphisms of A acting freely on A. 相似文献
102.
Khaled Beyaz Carlos Vaca-Garcia Emeline Vedrenne Nabila Haddadine Ahmed Benaboura Sophie Thiebaud-Roux 《International Journal of Polymer Analysis and Characterization》2019,24(3):245-256
In this work, we reported the preparation of a novel biomaterial, by graft-polymerization of 2-2-dimethyl-1-3-dioxolan-4-yl methyl acrylate (solketalacrylate, DMDMA) on hydroxyethyl cellulose (HEC) using KPS as initiator. Several experiments were performed to found the optimum conditions for the preparation of this biopolymer, by varying the time of the reaction as well as the initiator and the monomer ratio. Results showed that the highest grafting yield was 25%, obtained after 72?minutes at 65?°C, using THF as solvent. The structure of the grafted copolymer was confirmed by X-ray diffraction patterns which showed, besides the characteristic peaks of HEC at 2θ?=?31.74° and 44.63° a new peak at 2θ?=?30.72° related to an organized structure of the grafted polymer on the HEC backbone. The DSC analysis showed a single glass transition temperature Tg, intermediate between the corresponding values for HEC and neat poly(solketal acrylate). Moreover, the grafted biomaterial presented two-fold more moisture absorption ability by comparison with HEC, making this new synthetic biomaterial highly promising for dryness applications. In our knowledge, the synthesized monomer: 2-2-dimethyl-1-3-dioxolan-4-yl methyl acrylate, (solketal acrylate, DMDMA), has never been grafted on the HEC backbones before that is what makes the novelty of the present work. 相似文献
103.
Journal of Solid State Electrochemistry - This work discusses the possibility of obtaining ZnO film on graphite, which can be widely used for photocatalysis, photocells, photodetectors, etc. The... 相似文献
104.
Yassine Benmassaoud Khaled Murtada Rachid Salghi Mohammed Zougagh ngel Ríos 《Molecules (Basel, Switzerland)》2021,26(9)
In this study, we combine magnetic solid phase extraction (MSPE), with the screen-printed carbon electrode (SPCE) modified by a molecular imprinted polymer (MIP) for sensitive and selective extraction and electrochemical determination of Rhodamine B in food samples. A magnetic solid phase extraction (MSPE) was carried out using magnetic poly(styrene-co-divinylbenzene) (PS-DVB) and magnetic nanoparticles (MNPs) synthetized on the surface of multiwalled carbon nanotubes (MWCNTs). An MIP was prepared on the surface of MWCNTs in the presence of titanium oxide nanoparticles (TiO2NPs) modifying the SPCE for the rapid electrochemical detection of Rhodamine B. The MIPs synthesis was optimized by varying the activated titanium oxide (TiO2) and multiwalled carbon nanotubes (MWCNTs) amounts. The MSPE and electrochemical detection conditions were optimized as well. The present method exhibited good selectivity, high sensitivity, and good reproducibility towards the determination of Rhodamine B, making it a suitable method for the determination of Rhodamine B in food samples. 相似文献
105.
Khaled Tawfik Alali Dr. Jingyuan Liu Dr. Rongrong Chen Dr. Qi Liu Dr. Hongsen Zhang Jundong Li Jindi Hou Prof. Rumin Li Prof. Jun Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(51):11892-11902
Semiconductor metal oxides (SMO)-based gas-sensing materials suffer from insufficient detection of a specific target gas. Reliable selectivity, high sensitivity, and rapid response–recovery times under various working conditions are the main requirements for optimal gas sensors. Chemical warfare agents (CWA) such as sarin are fatal inhibitors of acetylcholinesterase in the nerve system. So, sensing materials with high sensitivity and selectivity toward CWA are urgently needed. Herein, micro-nano octahedral Co3O4 functionalized with hexafluoroisopropanol (HFIP) were deposited on a layer of reduced graphene oxide (rGO) as a double-layer sensing materials. The Co3O4 micro-nano octahedra were synthesized by direct growth from electrospun fiber templates calcined in ambient air. The double-layer rGO/Co3O4-HFIP sensing materials presented high selectivity toward DMMP (sarin agent simulant, dimethyl methyl phosphonate) versus rGO/Co3O4 and Co3O4 sensors after the exposure to various gases owing to hydrogen bonding between the DMMP molecules and Co3O4-HFIP. The rGO/Co3O4-HFIP sensors showed high stability with a response signal around 11.8 toward 0.5 ppm DMMP at 125 °C, and more than 75 % of the initial response was maintained under a saturated humid environment (85 % relative humidity). These results prove that these double-layer inorganic–organic composite sensing materials are excellent candidates to serve as optimal gas-sensing materials. 相似文献
106.
Electrospun Nanofibers from a Tricyanofuran‐Based Molecular Switch for Colorimetric Recognition of Ammonia Gas
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Dr. Tawfik A. Khattab Dr. Sherif Abdelmoez Prof. Dr. Thomas M. Klapötke 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(12):4157-4163
A chromophore based on tricyanofuran (TCF) with a hydrazone (H) recognition moiety was developed. Its molecular‐switching performance is reversible and has differential sensitivity towards aqueous ammonia at comparable concentrations. Nanofibers were fabricated from the TCF–H chromophore by electrospinning. The film fabricated from these nanofibers functions as a solid‐state optical chemosensor for probing ammonia vapor. Recognition of ammonia vapor occurs by proton transfer from the hydrazone fragment of the chromophore to the ammonia nitrogen atom and is facilitated by the strongly electron withdrawing TCF fragment. The TCF–H chromophore was added to a solution of poly(acrylic acid), which was electrospun to obtain a nanofibrous sensor device. The morphology of the nanofibrous sensor was determined by SEM, which showed that nanofibers with a diameter range of 200–450 nm formed a nonwoven mat. The resultant nanofibrous sensor showed very good sensitivity in ammonia‐vapor detection. Furthermore, very good reversibility and short response time were also observed. 相似文献
107.
In this paper our aim is to show some new inequalities of the Redheffer type for Bessel and modified Bessel functions of the first kind. The key tools in our proofs are some classical results on the monotonicity of quotients of differentiable functions as well as on the monotonicity of quotients of two power series. We also use some known results on the quotients of Bessel and modified Bessel functions of the first kind, and by using the monotonicity of the Dirichlet eta function we prove a sharp inequality for the tangent function. At the end of the paper a conjecture is stated, which may be of interest for further research. 相似文献
108.
El-Helby Abdel-Ghany A. Ayyad Rezk R. A. El-Adl Khaled Elkady Hazem 《Molecular diversity》2019,23(2):283-298
Molecular Diversity - In view of the anticonvulsant activity reported for phthalazine derivatives as non-competitive AMPA receptor antagonists, a new series of phthalazine-1,4-diones (2–12)... 相似文献
109.
110.
Reheim N. A. Abdel Geleel M. Abdel Mohammed Ashraf. A. Atta E. R. Elsawy Emtithal A. Tawfik Amaal 《Journal of Radioanalytical and Nuclear Chemistry》2019,322(2):455-465
Journal of Radioanalytical and Nuclear Chemistry - The current work aims at the preparation and characterization of novel composite materials of acrylic acid/charcoal/montmorillonite (MMT) (PAACM... 相似文献