排序方式: 共有60条查询结果,搜索用时 15 毫秒
31.
Sedigheh Borhani Seyed Gholamreza Etemad Seyed Abdolkarim Hosseini Ravandi 《Heat and Mass Transfer》2011,47(7):807-811
In this study a non-conventional electrospinning technique was designed for the production of high bulky polyacrylonitrile
(PAN) nanofiber mats. Optimum nanofiber mats are achieved with 15 wt.% solution of PAN in dimethylformamide. Such mats result
in a bulk porosity which is as high as 99.9 and a density as low as 0.84 × 10−3 g/cm3. The effect of the porosity of nanofiber mats on the air permeability and coupled heat and moisture transfer of fibers was
investigated. Based on the results, high bulky nanofiber mats possess high heat and moisture transfer. Experimental data reveal
that upon a slight decrease in the bulk porosity, air permeability and heat transfer decrease noticeably, while moisture transfer
variation is low. 相似文献
32.
Zare Abdolkarim Sadeghi-Takallo Masoud Karami Mostafa Kohzadian Alireza 《Research on Chemical Intermediates》2019,45(5):2999-3018
Research on Chemical Intermediates - A novel mesoporous nanomaterial, namely nano-N,N,N′,N′-tetramethyl-N-(silica-n-propyl)-N′-sulfo-ethane-1,2-diaminium chloride... 相似文献
33.
Ardeshir Khazaei Mohammad Ali Zolfigol Mohammad Mokhlesi Abdolkarim Zare Fatemeh Derakhshan‐Panah Maria Merajoddin Hassan Keypour Ahmad Ali Dehghani‐Firouzabadi 《中国化学会会志》2012,59(2):199-207
A highly efficient protocol for the synthesis of β‐acetamido ketone or ester derivatives in the presence of pyrazinium di(hydrogen sulfate) {Py(OSO3H)2} as a novel, green and homogeneous solid acid catalyst at room temperature is described. One‐pot multi‐component condensation of enolizable ketones or alkyl acetoacetates with aldehydes, acetonitrile and acetyl chloride affords the title compounds in high to excellent yields and in relatively short reaction times. In this work, the efficiency of our recently reported solid acid catalyst, saccharin sulfonic acid (Sa‐SO3H), in the synthesis of β‐acetamido ketones/esters is also studied. Moreover, in this research, some new β‐acetamido ketones and esters (i.e. one complex structure) are prepared. 相似文献
34.
In this work the copper oxide nanoparticles simultaneous with sol–gel‐derived carbon ceramic production were synthesized and doped in ceramic by microwave irradiation in a few minutes without using any catalyst and organic solvent. The ceramic composition was characterized by X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS) and Fourier transforms infrared (FT‐IR), and its surface morphology was investigated by scanning electron microscopy (SEM). The proposed ceramic with detection limit of 0.1 µM, was used for electrocatalytic determination of adenine at potential about 700 mV lower than its usual oxidation potential. 相似文献
35.
Khalafi-Nezhad A Parhami A Bargebid R Molazade S Zare A Foroughi H 《Molecular diversity》2011,15(2):373-381
A simple, clean and highly efficient method for the preparation of polyhydroxyl aromatic compounds is described from the reaction
of 2,6-bis(methylol)phenols and different substituted phenols in the presence of silica sulfuric acid (SSA) as a heterogeneous
catalyst. SSA afforded the clean synthesis of target compounds in much higher yields than traditional catalysts. The established
method is also suitable for the synthesis of phloroglucinol derivatives (Phloroglucides) and other polyhydric phenols. Besides
the easy work-up of the reaction mixture, the comfortable purification of the products is another advantage of this method. 相似文献
36.
Zare Abdolkarim Ghobadpoor Aysoda Safdari Tayebeh 《Research on Chemical Intermediates》2020,46(2):1319-1327
Research on Chemical Intermediates - In this research, firstly, preparation and characterization of a novel dicationic molten salt, namely N,N,N′,N′-tetramethylethylenediaminium... 相似文献
37.
A simple, clean and highly efficient solvent-free procedure for the preparation of primary, secondary, tertiary and aromatic amides is described from the direct reaction of carboxylic acids and silica-supported ammonium salts, triethylamine (TEA) and tosyl chloride (TsCl) as condensing agent. The reaction proceeds rapidly in high yields at room temperature. 相似文献
38.
A method for the determination of ascorbic acid in vitamin C tablets based on a very simple paptode design on TLC strips is described. This procedure is based on the reduction of iron(III) with ascorbic acid and the formation of a colorful red complex with immobilized 2,2'-dipyridyl (dipy) on TLC strips. The linear range of the system was 20-200 ppm with a detection limit of 1 ppm and a relative standard deviation of 1.5% (n = 28). The parameters, such as pH, concentration of iron(III), concentration of dipy and the volume of dipy per 1 cm(2) of TLC strips, were optimized. The proposed sensor was successfully applied for the determination of ascorbic acid in vitamin C tablets. 相似文献
39.
Ali Khalafi‐Nezhad Abdolkarim Zare Abolfath Parhami Mohammad Navid Soltani Rad Gholam Reza Nejabat 《合成通讯》2013,43(23):3549-3562
N‐Arylation of some pyrimidine and purine nucleobases in the presence of SiO2 and Cs2CO3 under solvent‐free as well as in solution conditions is described. In these conditions, N1‐aryl pyrimidines and N9‐aryl purines have been obtained regioselectively in moderate to high yields with relatively short reaction times. 相似文献
40.
Abdolkarim Zare Ahmad Reza Moosavi-Zare Abolfath Parhami Ali Khalafi-Nezhad Mohammad Hassan Beyzavi 《合成通讯》2013,43(17):3156-3165
Sulfonamides are efficiently condensed with aldehydes as well as ketones in the absence of catalyst in 1-butyl-3-methylimidazolium bromide ([bmim]Br) under microwave irradiation to afford N-sulfonyl aldimines and ketimines in good to excellent yields in short reaction times. 相似文献