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551.
Fahimeh Jalali Mohammad J Rajabi Gholamreza Bahrami Mojtaba Shamsipur 《Analytical sciences》2005,21(12):1533-1535
An iodide-miconazole ion-paired complex was used as a suitable ion-exchanger for the preparation of a plasticized-PVC membrane electrode. Among different solvent mediators tested, dioctylsebacate exhibited the proper response characteristics, including Nernstian slope of the calibration curve, fast response time and good reproducibility of the emf values. The electrode exhibits a Nernstian slope of -59.8 +/- 0.5 mV decade(-1) for I- ion over a concentration range of 1.0 x 10(-5) - 1.0 x 10(-2) M with a limit of detection of 7.0 x 10(-6) M. The electrode displays a good selectivity for I- with respect to a number of inorganic and organic species. It canbe used over a pH range of 2.5 - 8.5. The membrane sensor was successfully applied to the determination of iodide in water samples and blood serum, as well as in pharmaceutical products such as iodoquinol and thyroxin. 相似文献
552.
Mohammad Reza Ganjali Mohammad Yousefi Mehran Javanbakht Tahereh Poursaberi Masoud Salavati-Niasari Leila Hajiagha-Babaei Elnaz Latifi Mojtaba Shamsipur 《Analytical sciences》2002,18(8):887-892
The construction, performance characteristics, and application of a novel polymeric membrane coated on a graphite electrode with unique selectivity towards SCN- are reported. The electrode was prepared by incorporating Ni(II)-2,2,4,9,9,11-hexamethyltetraazacyclotetradecanediene perchlorate into a plasticized poly(vinyl chloride) membrane. The influences of membrane composition, pH and foreign ions were investigated. The electrode displays a near Nernstian slope (-57.8 mV decade-1) over a wide concentration range of 1 x 10(-7)-1 x 10(-1) M of SCN- ion. The electrode has a detection limit of 4.8 x 10(-8) M (2.8 ng/cm3) SCN- and shows response times of about 15 s and 120 s for low to high and high to low concentration sequences, respectively. The proposed sensor shows high selectivity towards SCN- over several common organic and inorganic anions. The electrode revealed a great enhancement in selectivity coefficients and detection limit for SCN-, in comparison with the previously reported electrodes. It was successfully applied to the direct determination of SCN- in milk and biological samples, and as an indicator electrode in titration of Ag+ ions with thiocyanate. 相似文献
553.
We introduce a Gentzen-style sequent calculus axiomatization for Basic Predicate Calculus. Our new axiomatization is an improvement
of the previous axiomatizations, in the sense that it has the subformula property. In this system the cut rule is eliminated.
Received: 18 April 2000 / Published online: 2 September 2002
Mathematics Subject Classification (2000): Primary 03F05; Secondary 03F99, 03B60
Key words or phrases: Basic predicate calculus – Cut elimination – Sequent 相似文献
554.
Mojtaba Shamsipur Armen Avanes Mehran Javanbakht Mohammad Reza Ganjali Hashem Sharghi 《Analytical sciences》2002,18(8):875-879
New polymeric membrane (PME) and coated graphite (CGE) copper(II)-selective electrodes based on 1-hydroxy-2-(prop-2'-enyl)-4-(prop-2'-enyloxy)-9,10-anthraquinone were prepared. The electrodes reveal linear emf-pCu2+ responses over wide concentration ranges (1.0 x 10(-5)-1.0 x 10(-1) M with a slope of 27.3 mV decade-1 for PME and 8.0 x 10(-8)-5.0 x 10(-2) M with a slope of 29.1 mV decade-1 for CGE) and very low limits of detection (8.0 x 10(-6) M for PME and 5.0 x 10(-8) M for CGE). The potentiometric response is independent of the pH of the test solution in the pH range 3.0-6.0. The proposed electrodes possess very good selectivities over a wide variety of other cations, including alkali, alkaline earth, transition and heavy metal ions, the selectivity coefficients for the CGE being much improved over those for the PME. The electrodes were used as indicator electrodes in the potentiometric titration of Cu2+ and in the recovery of copper ions from wastewater. 相似文献
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557.
Hossein Behniafar Mojtaba Yazdi Fatemeh Saki 《International Journal of Polymer Analysis and Characterization》2016,21(7):584-589
In this article, we report on the chemical oxidative polymerization of 3-methylthiophene (3MTh) in a concentrated TiO2/CHCl3 homogeneous suspension with an oxidant/monomer mole ratio of 3 at room temperature. According to the scanning electron microscopy images, in this condition, poly(3-methylthiophene) (P3MTh) was prepared with fibrous morphology decorated by nano-dimensional TiO2 particles. P3MTh/TiO2 was also characterized by Fourier transform infrared spectroscopy and X-ray diffraction techniques. It was found that no aggregation of nanoparticles occurred during the polymerization process. In addition, the thermal stability of P3MTh/TiO2 nanocomposite was investigated by thermogravimetric analysis and compared with that of an analogously prepared neat P3MTh. The thermal degradation of P3MTh in the temperature range of 300–550°C decreases significantly due to the presence of the TiO2 nanoparticles in the polymer composite. 相似文献
558.
Preparation and investigation of tribological properties of ultra‐high molecular weight polyethylene (UHMWPE)/graphene oxide 下载免费PDF全文
This article has been devoted to investigation of the tribological properties of ultra‐high molecular polyethylene/graphene oxide nanocomposite. The nanocomposite of ultra‐high molecular polyethylene/graphene oxide was prepared with 0.5, 1.5, and 2.5 wt% of graphene oxide and with a molecular weight of 3.7 × 106 by in‐situ polymerization using Ziegler–Natta catalyst. In this method, graphene oxide was used along with magnesium ethoxide as a novel bi‐support of the Ziegler–Natta catalyst. Analyzing the pin‐on‐disk test, the tribological properties of the nanocomposite, such as wear rate and mean friction coefficient, were investigated under the mentioned contents of graphene oxide. The results showed that an increase in graphene oxide content causes a reduction in both wear rate and mean coefficient friction. For instance, by adding only 5 wt% graphene oxide to the polymeric matrix, the wear rate and mean coefficient friction decreased about 34% and 3.8%, respectively. Also, the morphological properties of the nanocomposite were investigated by using X‐ray diffraction and scanning electron microscopy. In addition, thermal properties of the nanocomposite were analyzed using differential scanning calorimetry, under various contents of graphene oxide. The results of the morphological test indicated that the graphene oxide was completely exfoliated into the polymeric matrix without any agglomeration. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
559.
Synthesis,characterization, metal sorption,and biological activities of organosoluble and thermally stable azoxanthone‐based polyester 下载免费PDF全文
The aim of this work was to develop functionalized polyxanthones, poly(azoxanthone‐ester)s (PAXEs), with biological activities and heavy metal sorption abilities. For this purpose, at first, new xanthone‐based diol moiety was synthesized and then used for polymerization with commercial dicarboxylic acids via polycondensation reaction by Vilsmeier adducts. The monomer and all polymers were characterized by Fourier transform infrared (FTIR) and Nuclear magnetic resonance (NMR) spectroscopies, and the physical properties of these PAXEs including solution viscosity, solubility properties, thermal stability, and thermal behavior were studied. The prepared polyesters showed excellent thermal stability and good solubility in polar aprotic solvents. In addition, evaluation of antioxidant activity of the PAXEs by 2,2‐diphenyl‐1‐picrylhydrazyl assay revealed that synthesized polymers have higher antioxidant activity than xanthone nucleus. Also, evaluation of the antibacterial activities of the diol monomer and polymer showed good antibacterial activity against some bacterial strains (Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa). The results showed that these PAXEs can be used in pharmaceutical and food industry (food packaging). Furthermore, these functionalized polyesters were utilized for extraction of environmentally harmful metal cations such as Cr (VI), Co (II), Ni (II), Cu (II), Pb (II), and Cd (II) from aqueous solutions. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
560.
Mojtaba Amini Sajjad Bahadori Tekantappeh Bagher Eftekhari-Sis Parviz Gohari Derakhshandeh Kristof Van Hecke 《Journal of Coordination Chemistry》2017,70(9):1564-1572
A copper-containing polyoxovanadate nanocluster, [(C2H5)4N]4[V8Cu2O24]?2H2O (1), was synthesized through reaction between the Cu(NO3)2?3H2O and [(C2H5)4N]4VO3 in the molar ratio 1?:?4. Nanocluster 1 was characterized by IR, elemental analysis, XRD, SEM, TEM, and X-ray crystallography. The catalytic activity of 1 for the azide–alkyne cycloaddition of different terminal alkynes and organic azides generated in situ from sodium azide and different organic halides was tested. The protocol could afford the corresponding products in good to excellent yield at very low catalyst loadings (3.4 Mol%) under the optimized reaction conditions. 相似文献