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231.
Faramarz Rostami‐Charati Zinatossadat Hossaini Ebrahim Gharaee Mohammad A. Khalilzadeh 《Journal of heterocyclic chemistry》2013,50(Z1):E174-E177
A one‐pot synthesis of oxazine derivatives via reaction between activated acetylenic compounds, benzoyl cyanide, and N‐nucleophiles in water as the solvent is described?. 相似文献
232.
A four-component reaction between 2-formylbenzoic acid, malononitrile, isocyanides, and primary alkyl amines has been developed for an efficient preparation of 2-(1-(alkylcarbamoyl)-2,2-dicyanoethyl)-N-alkylbenzamide and 1,7-diazaspiro[4,4]nonane-2,6-dione derivatives under two different conditions. It is shown that simply by changing the reaction solvent from ethanol to dichloromethane and controlling the order of the addition of reagents, two completely different products can be obtained. These multicomponent reactions showed high atom economy. 相似文献
233.
The addition of arylboronic acids to isocyanates catalyzed by palladium acetate in the presence of triphenylphosphine as the ligand is described. 相似文献
234.
An efficient method for the synthesis of 14-alkyl or aryl 14H-dibenzo[a,j]xanthene derivatives by the reaction of β-naphthol,and aldehydes in the presence of a catalytic amount of bismuth(Ⅲ) chloride(BiCl3) under solvent-free conditions at 110℃is described.Aliphatic and aromatic aldehydes were used in the reaction and in all cases the desired products were synthesized successfully.This reaction was studied under different temperatures;the maximum yield was obtained in a short reaction period at 110℃.The method offers the advantages of high yields,short reaction times,simplicity and easy workup compared to the conventional method of syntheses. 相似文献
235.
Abstract We show that the multiplication algebra of a nondegenerate Jordan algebra is a semiprime algebra. 相似文献
236.
Taher Sharshar H. Ebrahim Hassan Hassan A. Arida Abdulkadir Aydarous Salih A. Bazaid Mamdouh A. Ahmed 《Isotopes in environmental and health studies》2013,49(1):132-151
The levels of radioactivity and heavy metals in soil, plant and groundwater samples collected from the area of the new campus of Taif University, Saudi Arabia, and its neighbouring areas have been determined. High-resolution gamma-ray spectroscopy was used for radioactivity measurements, and inductively coupled plasma atomic emission spectroscopy was used to determine the concentration of heavy metals. The means of 226Ra, 228Ra and 40K concentrations in water samples collected from four wells were found to be 0.13±0.03, 0.05±0.03 and 1.3±0.5 Bq l?1, respectively. The means of 238U, 226Ra, 228Ra (232Th for soil samples) and 40K concentrations in wild plant and soil samples were found to be 3.7±4.1, 8.8±11.6, 3.8±2.9 and 1025±685, and 8.6±3.4, 12.8±3.4, 16.6±7.1 and 618±82 Bq kg?1 dry weight (DW), respectively. The 137Cs of artificial origin was also detected in soil samples with a mean concentration of 3.8±2.2 Bq kg?1 DW. Evaluating the results, it can be concluded that the concentrations of 238U, 226Ra, 232Th and 40K in soil samples fall within the world average. Furthermore, 19 trace and major elements in groundwater samples and 22 elements in soil and plant samples were determined. The sampling locations of soil can be classified into three groups (relatively high, medium and low polluted) according to their calculated metal pollution index using the contents of trace and major elements. A cluster analysis of the contents of radioactivity and trace element contents in soil samples shows the presence of two main distinct clusters of sampling locations. 相似文献
237.
A. A. Ebrahim 《Physics of Atomic Nuclei》2013,76(4):435-449
π ±-Nucleus scattering cross sections are calculated applying the Watanabe superposition model with a phenomenological Woods-Saxon potential. The phenomenological potential parameters are searched for π ± scattering from 6Li and 12C to reproduce not only differential elastic cross sections but also inelastic and total and reaction cross sections at pion kinetic energies from 50 to 672 MeV. The optical potentials of 6Li and 12C are calculated in terms of the alpha particle and deuteron optical potentials. Inelastic scattering has been analyzed using the distorted waves from elastic-scattering data. The values of deformation lengths thus obtained compare very well with the ones reported earlier. 相似文献
238.
Coupled-channels calculations for the elastic and inelastic scattering of K+ at 715 MeV/c by 6Li and 12C at 635, 715 and 800 kaon Lab momenta have been analysed. The optical potentials of 12C and 6Li are calculated in terms of the alpha-particle and deuteron optical potentials. Good fits to the experimental data and phenomenological
calculations are obtained for 6Li and 12C nuclei. 相似文献
239.
240.
A green palladium‐based catalyst supported on Artemisia abrotanum extract‐modified graphene oxide (Pd NPs/RGO‐A. abrotanum) hybrid material has been used as a recoverable and heterogeneous nanocatalyst for the catalytic reduction of various dyes, including methylene blue, methyl orange and rhodamine B, in the presence of NaBH4 as reducing agent in aqueous medium at room temperature. With the help of UV–visible spectroscopy, the catalytic reactions were investigated. According to the results, these reactions followed the pseudo‐first‐order rate equation. 相似文献