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151.
Mahsa Baghban Salehi Ebrahim Vasheghani‐Farahani Mohsen Vafaie Sefti Asefe Mousavi Moghadam Hasan Naderi 《先进技术聚合物》2014,25(4):396-405
In this research, an optimal hydrogel, based on sulfonated polyacrylamide, was synthesized by statistical design of experiments using central composite method. This new hydrogel composed of sulfonated polyacrylamide (AN125VLM) and chromium triacetate as copolymer and crosslinker, respectively. The bottle and rheological tests were conducted to investigate the gelation time, thermal stability, gel strength and also ultimate elastic modulus, complex modulus, and yield stress. It was found that copolymer concentration had the main effect in both rheological and transport properties of hydrogels. The sample prepared at optimum condition, i.e. copolymer concentration of 26,340 ppm and crosslinker/copolymer ratio of 0.12, had an ultimate elastic modulus of 29.9 kPa, yield stress of 800 Pa, and complex modulus of 32 kPa. A coreflooding test through fracture was carried out to examine the optimum gel performance in a porous media. A value of 483 for the residual resistance factor ratio of water to oil confirmed the high ability of the hydrogel in reducing the relative permeability of water to oil in fractured media. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
152.
p‐Toluenesulfonic acid catalyzed the one‐pot, three‐component synthesis of 3‐aminoimidazo[1,2‐a]pyridines and pyrazines through a condensation reaction of a 2‐aminoazine, an aldehyde, and an isocyanide at room temperature. This methodology affords a number of 3‐aminoimidazo[1,2‐a]pyridines in reasonable yields and short reaction times without any significant optimization of the reaction conditions. 相似文献
153.
Journal of Fourier Analysis and Applications - Let G be a discrete group, let $$p\ge 1$$, and let $$\omega $$ be a weight on G. Using the approach from Gröchenig and Klotz (J Lond Math Soc (2)... 相似文献
154.
Substituted 5-Antipyrinylazo-4-phenyl-2-aminothiazoles as Disperse Dyes for Dyeing Polyester Fabrics
Mohamed A. Metwally Amira Metwally Ebrahim Abdel-Galil Fathy A. Amer 《Monatshefte für Chemie / Chemical Monthly》2008,9(2):35-42
A series of some new substituted 5-antipyrinylazo-4-phenyl-2-aminothiazole disperse dyes was synthesized by diazocoupling
of 4-antipyrinyldiazonium chloride with aminothiazole derivatives. The synthesized dyes were characterized by UV-Vis absorption,
IR, 1H NMR, and MS spectroscopy. The dyes gave orange to reddish-violet shades with very good depth and levelness when applied
to polyester fabrics as disperse dyes and their fastness properties were evaluated on polyester fibers. Also the position
of color in CIELAB coordinates (L*, a*, b*, H*, and C*) was assessed. 相似文献
155.
π+-nucleus scattering cross section are calculated by solving a Schrödinger equation reduced from the Klein-Gordon equation. Local potentials are assumed, and phenomenological potential parameters are searched energy dependently for π+ scattering from 12C, 40Ca, and 208Pb to reproduce not only differential elastic cross sections but also inelastic and total and reaction cross sections at 800 MeV/c pion laboratory momentum. The collective model is used to calculate the angular distributions of differential inelastic cross sections for pions leading to the lowest 2+ and 3? states of 12C. The deformation parameters and lengths are extracted and compared to the corresponding ones from other works. Local potentials well describe the scattering of pions from nuclei. 相似文献
156.
A simple and sensitive flow injection method with spectrophotometric detection was developed for the determination of formaldehyde. The method is based on the catalytic effect of formaldehyde on the oxidation of sulfonazo III with bromate in acidic media. The decrease in absorbance of the reaction mixture was measured at 566 nm. The calibration graph was linear in the range of 0.005 to 2.80 microg ml(-1) formaldehyde at a rate of 38 +/- 4 samples h(-1). The limit of detection was 4 ng ml(-1). The relative standard deviations for ten replicate measurements of 0.20, 0.50 and 1.00 microg ml(-1) formaldehyde were 1.3, 0.8 and 0.7%, respectively. The method was applied to the determination of formaldehyde in river water, shampoo and melamine-formaldehyde resin. 相似文献
157.
We present detailed characteristics of heated electron distributions in long-scale-length underdense plasmas irradiated by intense nanosecond CO2 laser radiation. Below nc/4, the heated electron distributions are consistent with heating by Raman instability. 相似文献
158.
Ebrahim Samei 《Journal of Mathematical Analysis and Applications》2008,346(2):451-467
Let be a Beurling algebra on a locally compact abelian group G. We look for general conditions on the weight which allows the vanishing of continuous derivations of . This leads us to introducing vector-valued Beurling algebras and considering the translation of operators on them. This is then used to connect the augmentation ideal to the behavior of the derivation space. We apply these results to give examples of various classes of Beurling algebras which are weakly amenable, 2-weakly amenable or fail to be even 2-weakly amenable. 相似文献
159.
A novel pseudo-four-component condensation yielding 1-aminoimidazo[5,1- a]isoquinolinium salts from isocyanides, isoquinoline, and sulfonic or bromic acids is described. The method offers several advantages including high yields of products and an easy experimental workup procedure. 相似文献
160.
Application of tandem dispersive liquid–liquid microextraction for the determination of doxepin,citalopram, and fluvoxamine in complicated samples 下载免费PDF全文
Bahareh Fahimirad Alireza Asghari Mohammad Bazregar Maryam Rajabi Ebrahim Fahimi 《Journal of separation science》2016,39(24):4828-4834
A new type of dispersive liquid–liquid microextraction is used for the determination of doxepin, citalopram, and fluvoxamine in aqueous matrices. This method is based upon the tandem utilization of dispersive liquid–liquid microextraction, and by providing a high sample clean‐up, it efficiently improves the applicability of the method in complicated matrices. For this purpose, in the first step, the analytes contained in an aqueous sample solution (8.0 mL) were extracted into an organic solvent, and then these analytes were simply back‐extracted into an aqueous acceptor phase (50 μL). The overall extraction time was 7 min, and very simple tools were required for this aim. Optimization of the variables affecting the method such as the type and volume of the organic solvent used and effect of ionic strength was carried out to achieve the best extraction efficiency. Under the optimized experimental conditions, tandem dispersive liquid–liquid microextraction with high‐performance liquid chromatography and UV detection showed a good linearity in the range of 10–5000 ng/mL. The limits of detection were in the range of 3–10 ng/mL. The Intra‐day precisions (relative standard deviation) were 9.2, 4.5, and 4.8, and the recoveries were 58.5, 52.9, and 39.3% for citalopram, doxepin, and fluvoxamine, respectively. 相似文献