排序方式: 共有75条查询结果,搜索用时 15 毫秒
61.
Research on Chemical Intermediates - Efficient organocatalyst for enantioselective Strecker reaction was synthesized using g-C3N4 sheets (CN). CN-anchored sulfonic acid (CN-Bu-SO3H) was found to be... 相似文献
62.
Henri Vahabi Fouad Laoutid Elnaz Movahedifar Reza Khalili Negar Rahmati Christelle Vagner Marianne Cochez Loic Brison Franck Ducos Mohammad Reza Ganjali Mohammad Reza Saeb 《先进技术聚合物》2019,30(8):2056-2066
This work visualizes the complementary actions of organic and mineral additives in model thermoplastic polymer composites in terms of Flame Retardancy Index (FRI). Thermal and flame retardancy behaviors of ethylene‐vinyl acetate copolymer (EVA) composites containing calcium carbonate (CC) mineral and ammonium polyphosphate (APP) organic additives were studied varying composition of additives in the 80/20 EVA/(xCC + (20 ? x)APP) composites with x denoting 0, 5, 10, 15, and 20 wt%. Thermogravimetric analysis (TGA) revealed that the onset temperature of composites and the remaining residue were increased by combination of APP and CC, while cone calorimetry results were indicative of a promising flame retardancy performance at a given composition of APP and CC. Based on FRI values, we made distinguished samples from flame retardancy performance viewpoint, where the best flame retardancy was obtained by combination of 15 wt% APP and 5 wt% CC, as reflected in FRI value of 3.08. By contrast, samples containing only APP or CC revealed low resistance against flame, as signaled by FRI values of 0.99 and 0.89, respectively. X‐ray diffraction (XRD) analysis was made on remaining residue collected at the end of cone calorimetry measurements. Moreover, Raman analysis confirmed barrier effect of flame retardancy for EVA/(5APP + 15CC) sample, featured by a higher graphitization level as well as a thicker yet more homogenous char layer. Mechanical behavior analysis of composites revealed an acceptable level of properties, particularly high elongation at break, which was almost independent of formulation. However, a minor loss in yield stress was observed, especially for EVA(10CC + 10APP) sample. 相似文献
63.
Sajad Mousavifaraz Zahra Nadealian Valiollah Mirkhani Abbas Rahmati 《Journal of the Iranian Chemical Society》2017,14(8):1753-1763
In this research, two heterogeneous organic–inorganic hybrid catalysts, [bmim]3[PW12O40]·3H2O and [bmim]5[PNiW11O39]·3H2O, have been prepared. The catalysts were fully characterized by several techniques such as elemental analyses, Fourier transform infrared spectroscopy, thermo-gravimetric analysis, scanning electron microscope and energy-dispersive X-ray analysis. Next, the hybrid catalysts have been used for the synthesis of functionalized diazepines containing tetrazole ring. Tetrazolyl-1H-spiro[benzo[b]cyclopenta[e][1,4] diazepines products were obtained in excellent yields and mild experimental conditions using [bmim]5[PNiW11O39]·3H2O as catalyst. This process was carried out via a one-pot, pseudo-five-component condensation reaction by means of a 1,2-diamine, isocyanide, TMSN3 and two molecules of a linear or cyclic ketone in methanol, at ambient temperature. 相似文献
64.
Ardeshir Khazaei Sadegh Rahmati Arash Ghaderi Leila Roshani 《Journal of the Iranian Chemical Society》2014,11(1):263-269
Palladium nanoparticles (2–8 nm) supported on gum arabic has been prepared under green conditions in water. Gum arabic has been used as both support and reducing agent. These nanoparticles have been characterized by UV–Vis, XRD and EDX spectra as well as SEM and TEM images. The nanoparticles have been applied as the catalyst in Mizoroki-Heck reaction of different aryl halides (I, Br, Cl) with butyl acrylate in the presence of n-Pr3N under solvent-free conditions at 140 °C. The reusability of the catalyst was also checked for five consecutive runs. 相似文献
65.
Ahmad Shaabani Ali H. Rezayan Abbas Rahmati Masoumeh Sharifi 《Monatshefte für Chemie / Chemical Monthly》2006,137(1):77-81
Summary. Hantzsch 1,4-dihydropyridine compounds were synthesized efficiently in high yields at room temperature within short times in 1,1,3,3-N,N,N′,N′-tetramethylguanidinium trifluoroacetate as ionic liquid using ultrasound irradiation. The ionic liquid can be recovered conveniently
and reused efficiently. 相似文献
66.
3-(2′-Benzothiazolo)-2,3-dihydroquinazolin-4(1H)-ones have been synthesized in high yields in the presence of 1-butyl-3-methylimidazolium bromide [bmim]Br as an ionic liquid; the reaction work-up is simple and the ionic liquid can be easily separated from the product and reused. 相似文献
67.
Abbas Rahmati 《Comptes Rendus Chimie》2012,15(8):647-652
A one-pot, domino three-component condensation reaction of an aldehyde, 3(5)-amino-5(3)-methylpyrazole and malononitrile in ethanol to give 2-alkyl-7-amino-5-aryl-pyrazolo[1,5-a]pyrimidine-6-carbonitrile in high yields at reflux condition without using any catalyst, is described. 相似文献
68.
Amin Rostami Sadegh Rahmati Ardeshir Khazaei 《Monatshefte für Chemie / Chemical Monthly》2009,140(6):663-667
Abstract Molecular iodine generated in situ from Fe(NO3)3·9H2O/NaI acts as a highly efficient catalyst for tetrahydropyranylation of various alcohols and phenols with 3,4-dihydro-2H-pyran in almost quantitative yields. The reaction occurs rapidly in dichloromethane at room temperature, and use of toxic
molecular iodine is avoided.
Graphical Abstract
相似文献
69.
Hamidreza Rahmati 《Archiv der Mathematik》2009,92(1):26-34
A finite module M over a noetherian local ring R is said to be Gorenstein if Exti(k, M) = 0 for all i ≠ dim R. An endomorphism φ: R → R of rings is called contracting if for some i ≥ 1. Letting φR denote the R-module R with action induced by φ, we prove: A finite R-module M is Gorenstein if and only if HomR(φR, M) ≅ M and ExtiR(φR, M) = 0 for 1 ≤ i ≤ depth R.
Received: 7 December 2007 相似文献
70.
Ahmad Shaabani Ali H. Rezayan Abbas Rahmati Masoumeh Sharifi 《Monatshefte für Chemie / Chemical Monthly》2006,56(7):77-81
Hantzsch 1,4-dihydropyridine compounds were synthesized efficiently in high yields at room temperature within short times in 1,1,3,3-N,N,N′,N′-tetramethylguanidinium trifluoroacetate as ionic liquid using ultrasound irradiation. The ionic liquid can be recovered conveniently
and reused efficiently. 相似文献