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排序方式: 共有257条查询结果,搜索用时 31 毫秒
1.
Mahmoud Roushani Zahra Saedi Fatemeh Hamdi Hamid Reza Rajabi 《Journal of the Iranian Chemical Society》2018,15(10):2241-2249
In this study, a new Cr(III)-imprinted polymer (Cr(III)-IIP) is prepared from CrCl3·6H2O, methacrylic acid functional monomer, ethyleneglycoldimethacrylate cross-linking agent, 2,2?-azobisisobutyronitrile radical initiator and 2,2-(azanediylbis (ethane-2,1-diyl))bis(isoindoline-1,3-dione) ligand. To obtain the maximum adsorption capacity, the optimum condition was studied through pH, type and concentration of eluent, IIP weight, sample volume as well as the adsorption and desorption times. The Cr(III) ion content was determined via flame atomic absorption spectrometer. In optimum conditions, the adsorption capacity of the IIP for Cr(III) was obtained to be 74.65 mg g?1, using 50 mg of IIP and the initial pH solution of 3.0. Both the adsorption and desorption times for quantitative analyses of Cr(III) ions were 15 and 5 min; respectively. After elution of the adsorbed ions by 3 mL of 4 mol L?1 HNO3 aqueous solution, the established IIP-based SPE procedure provides a reasonable pre-concentration factor of 100. The IIP-based pre-concentration method provides a low detection limit of 1.7 µg L?1 with good repeatability (RSD?=?3.22%). Reusability studies confirmed that synthesis IIP is reusable and recoverable up to six cycles. According to the selectivity experiments, it was concluded that the prepared sorbent possesses more affinity toward Cr(III) ions than other ions such as Al3+, Pb2+, Cu2+, Mn2+, Fe2+, Zn2+, and Ni2+ ions. To evaluate the potential applicability of the proposed separation method, the pre-concentration and determination of trace amounts of Cr(III) were performed successfully in food samples with complex matrices, a bestial sample (i.e. cow liver) and an herbal product (i.e., broccoli) as real samples. 相似文献
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Hamdi Ben Halima Abdelhamid Errachid Nicole Jaffrezic-Renault 《Electroanalysis》2023,35(1):e202100451
The review presents advances and main challenges of the affinity sensors based on field- effect transistors published during the last five years. The different nanomaterial-based field-effect transistors are classified according to the nature of the nanomaterials, beginning by silicon, the “gold-standard” semiconductor, the gallium nitride semiconductor, the organic semiconductors, the silicon nanowires, the inorganic nanomaterials, the carbon nanotubes and the graphene. Due to its exceptional electrical properties, the main works are devoted to graphene. The obtained analytical performances for the detection of biomarkers, of DNA sequences and of miRNA are listed. The relation between the operational conditions - nature of the nanomaterials, procedure of preparation, choice of the receptor molecule, method of immobilization – and the analytical performance are discussed. The perspective of industrialization of these affinity sensors based on field-effect transistors is discussed. 相似文献
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Serkan Yavuz Hamdi Özkan Gülçin Tok Ali Dişli 《Journal of heterocyclic chemistry》2013,50(6):1437-1440
The substituted pyrolidine derivatives with high stereoselectivity were obtained through cycloaddition reaction in the presence of a Lewis acid namely diethylzinc by solvent‐free grinding method. 相似文献
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In this work, biaxially stretched polymer foams with well‐defined cellular structures were prepared from polyethylene via blown‐film extrusion and subjected to corona charging to produce a piezoelectric response. The charging parameters were first optimized in terms of charging voltage and needle distance, as well as the gas type and pressure to investigate their effect on the piezoelectric coefficient (d33). The results show that samples charged under nitrogen (N2) at 100 kPa had better d33 coefficient than those charged under ambient air or N2 at 20 kPa. Moreover, 2 different thermal pressure treatments were imposed to obtain an optimized eye‐like cellular structure with different cell aspect ratios (AR). The results showed that when the cells were elongated in both the longitudinal and transverse directions (higher AR), higher d33 coefficients were achieved. From all the samples produced, the best results were obtained for a longitudinal aspect ratio (AR‐L) of 7.1, a transversal aspect ratio (AR‐T) of 4.6, and a relative foam density of 0.52 leading to a d33 coefficient of 935 pC/N. This coefficient was further increased using reverse charging and multilayered films, reaching a maximum of 2550 pC/N. This value is much higher than typical ones reported so far for any polyethylene and polypropylene ferroelectrets. These results could increase the use of polyethylene in piezoelectric applications as these materials are very attractive for the large‐scale production of electret‐based sensors and transducers due to their low cost and easy processing. 相似文献
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Electrical and photoelectrical behaviour of heterojunctions based on novel oligomeric metal complexes 下载免费PDF全文
Metin Atlan Yusuf Selim Ocak Salih Pasa Hamdi Temel Ahmet Tombak Tahsin Kilicoğlu Kemal Akkilic Murat Aydemir 《应用有机金属化学》2015,29(12):798-804
Naringenin‐based Schiff base ligands with 4‐aminobenzoic hydrazide were obtained as a unilateral form ( L1 ). The ligand was oligomerized by oxidative polycondensation reaction with NaOCl as an oxidant in an aqueous alkaline medium at 90 °C to form a functional oligomer ( L2 ), and its transition metal complexes such as those with Cu(II), Ni(II) and Zn(II) were prepared. The monomer and the oligomeric compounds were characterized using various techniques. Optical and electrical properties of the complexes were also investigated. All compounds showed indirect band gaps and they can be accepted as being in the semiconductor class. Organic–inorganic hybrid devices were obtained using n‐Si inorganic semiconductor and the complexes. The characteristic parameters of the devices were determined using current–voltage (I–V) and capacitance–voltage measurements in the dark. Photoelectrical properties of the devices were investigated using I–V measurements under a solar simulator with an AM1.5 global filter. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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Fuks Olga Ibrahima Fayadhoi Tomin Pavel Tchelepi Hamdi A. 《Transport in Porous Media》2019,126(1):115-137
Transport in Porous Media - In the context of stochastic two-phase flow in porous media, one is often interested in estimating the statistics of fluid saturations in the reservoir. In this work, we... 相似文献
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Aycha Jellali Slim Elleuch Besma Hamdi Ridha Zouari 《Journal of Saudi Chemical Society》2019,23(5):600-611
In this work, a new hybrid material (C5H6N2Cl)2[FeCl4].Cl abbreviated (CAP)2[FeCl4].Cl was prepared using room temperature slow evaporation technique. The X-ray diffraction analysis revealed that the compound is crystallized in the centrosymmetric space group P21/c of the monoclinic system. The crystallographic network consists of an Fe(III) ion located on an inversion center and coordinated by four chlorine, isolated Cl– and two (CAP)+ protonated cations linked by N–H...Cl and C–H...Cl hydrogen bonds to form a zero-dimensional network. Hirshfeld surface analysis was used to analyze intermolecular interactions present in the crystal structure. The vibrational properties were inspected by means of Infra-Red absorption and Raman diffusion spectroscopy techniques. In addition, theoretical calculations based on the DFT/B3LYP/LanL2DZ method and the time-dependent density functional theory (TD–DFT) were performed in order to gain more information and help in the examination of over-all properties of the title compound. Good and interesting experimental findings were presented and good consistency was found with the calculated results. 相似文献