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Majid M. Heravi Marzieh Khorasani Fatemeh Derikvand Hossein A. Oskooie Fatemeh F. Bamoharram 《Catalysis communications》2007,8(12):1886-1890
A variety of heteropolyanions including: Keggin, Dawson, Preyssler, mixed addenda and sandwich types, catalyzed the formation of 4-methylnaphtho-(1,2-b)-pyran-2-one (coumarin) from the condensation of α-naphthol and ethylacetoacetate in a solvent free system and under heating conditions. Our data vividly indicate that sodium30–tungsto pentaphosphate, [NaP5W30O110]14−, which so-called Preyssler’s anion, with high hydrolytic (pH 0–12) and thermal stability is the catalyst of choice. This catalyst catalyzed the synthesis of other coumarin derivatives in high yields and good selectivity. 相似文献
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Abbas Teimouri Marzieh Mahmoudsalehi Hossein Salavati 《International Journal of Hydrogen Energy》2018,43(31):14816-14833
As a series of bimetallic nanocatalysts, molybdenum/vanadium oxides supported on the silica (MoO3/V2O5/MCM-41) were prepared by the impregnation. Their catalytic activity in the oxidation of dibenzothiophene was investigated using H2O2 as an oxidant. Textures and surface properties of the prepared catalysts were characterized using FT-IR, XRD, FESEM-EDX and N2 adsorption/desorption techniques. The effects of main process variables including H2O2/DBT molar ratio, catalyst dosage, reaction temperature and reaction time were analyzed by employing the response surface methodology (RSM). The effect of the MoO3/V2O5 loading on the catalytic performance of the catalysts was also investigated. The results indicated that the catalytic activity of the catalyst was increased by enhancing the MoO3/V2O5 content. Thus, the catalyst with high MoO3/V2O5 loading (20%MoO3/20%V2O5/60%MCM-41) indicated the highest catalytic activity and could convert 99.06% of dibenzothiophene under the optimum conditions. Mass and FT-IR analysis demonstrated that the major product of dibenzothiophene oxidation was its corresponding sulfone. The catalyst could be recycled five times without any considerable reduction in its catalytic activity. The kinetics of the reaction fitted the pseudo-first-order equation pretty well. Eventually, a reaction mechanism for the catalytic oxidation of DBT in the presence of MoO3/V2O5/MCM-41 was proposed. 相似文献
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Javad Safaei-Ghomi Marzieh Kiani Abolfazl Ziarati Hossein Shahbazi-Alavi 《Journal of Sulfur Chemistry》2014,35(4):450-457
ZrP2O7 nanoparticles as an efficient catalyst have been used for the preparation of benzopyrano[2,3-b]pyridines from the four-component condensation reaction of salicylalde-hydes, thiols, and 2 equiv. of malononitrile under reflux conditions in ethanol in excellent yields and short reaction times. 相似文献
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Scientometrics - In this era of interdisciplinary science, many scientific achievements, such as artificial intelligence (AI), have brought dramatic revolutions to human society. The increasing... 相似文献
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Moein Bashash Nafiseh Zamindar Marzieh Bolandi 《Sensing and Instrumentation for Food Quality and Safety》2014,8(3):213-217
The antioxidant capacity and phenolic content of three sumac (Rhus coriaria L.) samples, including brown sumac fruit, brown sumac powder and red sumac powder were investigated in the present study. Methanol, ethanol, distilled water, and a mixture of methanol and ethanol (1:1) were used as solvent systems. Antioxidant activities of extracts were screened using 1,1-diphenyl-2-picrylhydrazyl DPPH radical scavenging method. Phenolic content was determined through Folin–Ciocaltaeu procedure. The efficiency of the solvents used to extract phenols from the samples varied considerably. The phenolic content of brown sumac powder ranged from 2.906 to 2.997 gallic acid equivalents/100 g (GAE/100 g), while that of the brown sumac fruit was 2.438–2.529 GAE/100 g, and that of the red sumac powder was 2.172–2.263 GAE/100 g. Findings indicated that water extracts of sumac have effective antioxidant and radical scavenging activities as compared to other extracts. 相似文献
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Abbas Saghaei Marzieh Mehrjoo Amirhossein Amiri 《The International Journal of Advanced Manufacturing Technology》2009,45(11-12):1252-1260
In most statistical process control applications, the quality of a process or product is characterized by univariate or multivariate quality characteristics and monitored by the corresponding univariate and multivariate control charts, respectively. However, sometimes, the quality of a process or a product is better characterized by a relationship between a response variable and one or more explanatory variables. This relationship, which can be linear, nonlinear, or even a complicated model, is referred to as a profile. So far, several methods have been proposed for monitoring simple linear profiles. In this paper, a new method based on cumulative sum statistics is proposed to enhance monitoring of linear profiles in phase II. The performance of the proposed method is evaluated by average run length criterion. A comprehensive comparison is also conducted between the performance of the proposed method and the existing methods for monitoring simple linear profiles. The results show that the proposed method performs satisfactorily. In addition, the effects of reference value, sample size, and corrected sum of squares of explanatory variables on the performance of the proposed method are investigated. 相似文献
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Farhad Panahi Marzieh Bahmani Nasser Iranpoor 《Advanced Synthesis \u0026amp; Catalysis》2015,357(6):1211-1220
The reductive benzylation of aromatic and aliphatic aldehydes with benzylic halides is reported using a nickel/zinc catalyst system. In addition to benzylic halides, the first report on the addition of benzylic triflates, acetates, tosylates and tritylates to aldehydes is also presented. By this new method a range of alcohols was synthesized efficiently from aldehydes and benzylic substrates at room temperature in moderate to high yields. The mild reaction conditions and good functional group tolerance make this nickel‐catalyzed process synthetically useful for the synthesis of diverse benzylic alcohols.