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Mohammad Reza Ganjali Morteza HosseiniFatemeh Basiripour Mehran JavanbakhtOmid Reza Hashemi Majid Faal RastegarMojtaba Shamsipur Gerald.W Buchanen 《Analytica chimica acta》2002,464(2):181-186
A novel selective membrane electrode for determination of ultra-trace amount of lead was prepared. The PVC membrane containing N,N′-dimethylcyanodiaza-18-cown-6 (DMCDA18C6) directly coated on a graphite electrode, exhibits a Nernstian response for Pb2+ ions over a very wide concentration range (from 1.0×10−2 to 1.0×10−7 M) with a limit of detection of 7.0×10−8 M (∼14.5 ppb). It has a fast response time of ∼10 s and can be used for at least 2 months without any major deviation in potential. The electrode revealed very good selectivity with respect to all common alkali, alkaline earth, transition and heavy metal ions. The proposed sensor was used as an indicator electrode in potentiometric titration of lead ions and in determination of lead in edible oil, human hair and water samples. The proposed sensor was found to be superior to the best Pb2+-selective electrodes reported in terms of detection limit and selectivity coefficient. 相似文献
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Naghmeh Esfandiary Farzane Pazoki Athar Nakisa Kobra Azizi Iman Radfar Akbar Heydari 《应用有机金属化学》2020,34(8):e5725
A highly efficient Fe3O4@VitB1–Ag(I) magnetic catalyst has been obtained using surface modification of Fe3O4. To this end, silver chloride was immobilized on Fe3O4 nanoparticles via vitamin B1 biomolecules. The synthesized biocompatible magnetic catalyst was applied in an A3-coupling reaction in the presence of aldehyde, amine and phenyl acetylene under solvent-free conditions and afforded the desired products in excellent yields. Also, interactions between metal and ligand in the Fe3O4@VitB1–Ag(I) were studied using theoretical calculations. 相似文献
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Sadeghi Mohamad Sadegh Anadalibkhah Naghmeh Ghasemiasl Ramin Armaghani Taher Dogonchi Abdul Sattar Chamkha Ali J. Ali Hafiz Asadi Amin 《Journal of Thermal Analysis and Calorimetry》2022,147(1):1-22
Journal of Thermal Analysis and Calorimetry - The ultimate goal of the present review paper is to summarize and discuss the findings of the most recently published literature on natural convection... 相似文献
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Molecular imprinted solid-phase extraction (MISPE) is a well known technique for the selective extraction and pre-concentration
of analytes, are present at low levels in chemically complex materials. Herein, water-soluble, molecularly imprinted polymers
(MIP) were prepared for solid-phase extraction of pseudoephedrine hydrochloride (PSE), which was monitored at 256 nm by the
UV spectroscopy. MISPE conditions were optimized to allow the selective and determination of PSE in aqueous samples and composite
materials, such as biological fluids and human urine. MIP was prepared by precipitation polymerization method, using methacrylic
acid as a functional monomer and ethylene glycol dimethacrylate as a cross-linking agent in either acetonitrile or chloroform.
The results suggest that the obtained MISPE exhibits high affinity for PSE, and the imprinted polymer demonstrates much higher
efficiency than a non-imprinted polymer (NIP). The imprinting-induced extraction was confirmed by the determination of recovery
values for NIP (4%) and MIP (80%) polymers, respectively. The binding capacity of the MIP for PSE was found of 47.6 mg g−1. 相似文献
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Let X and Y be two independent and nondegenerate random variables such that X is symmetric about a and Y is symmetric about b. It is shown that XY is symmetric about ab if and only if ab= 0. 相似文献
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Bayes-empiric Bayes estimation of the parameter of certain one parameter discrete exponential families based on orthogonal polynomials on an interval (a, b) is introduced. The resulting estimator is shown to be asymptotically optimal. The application of this method to three special distributions, the binomial, Poisson and negative binomial, is discussed.The first author was supported by NSF grant DCR-8504620. 相似文献
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