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We will study all finite groups and their subgroups with at most four relative centralizers. 相似文献
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Novel 1,2,3,4‐Tetrahydroquinazolinones via Reaction of 2‐Amino‐N‐substituted Benzamides and Dimethyl Acetylenedicarboxylate 下载免费PDF全文
Semiramis Nahavandian Sadegh Allameh Mina Saeedi Shirin Ansari Mohammad Mahdavi Alireza Foroumadi Abbas Shafiee 《Helvetica chimica acta》2015,98(7):1028-1033
Reaction of 2‐amino‐N‐substituted benzamides and dimethyl acetylenedicarboxylate (DMAD) in the presence of 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) in H2O at room temperature led to the formation of novel 1,2,3,4‐tetrahydroquinazolinones. 相似文献
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Zahra Najafi Mohammad Mahdavi Maliheh Safavi Mina Saeedi Heshmatollah Alinezhad Mahboobeh Pordeli Sussan Kabudanian Ardestani Abbas Shafiee Alireza Foroumadi Tahmineh Akbarzadeh 《Journal of heterocyclic chemistry》2015,52(6):1743-1747
New derivatives of triazole‐isoxazole were synthesized through a four‐step reaction starting from various ethyl 4‐aryl‐2,4‐dioxobutanoate derivatives. Finally, all compounds were examined by MTT assays for cytotoxic activity in two human breast cancer cell lines (MCF‐7 and T‐47D). 相似文献
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In this paper, an efficient method for solving nonlinear Stratonovich Volterra integral equations is proposed. By using Bernoulli polynomials and their stochastic operational matrix of integration, these equations can be reduced to the system of nonlinear algebraic equations with unknown Bernoulli coefficient which can be solved by numerical methods such as Newton’s method. Also, an error analysis is valid under fairly restrictive conditions. Furthermore, in order to show the accuracy and reliability of the proposed method, the new approach is compared with the block pulse functions method by some examples. The obtained results reveal that the proposed method is more accurate and efficient than the block pulse functions method. 相似文献
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Marzieh Saeedi Maryam Anafcheh Reza Ghafouri Nasser L. Hadipour 《Structural chemistry》2013,24(2):681-689
Density functionla theory (DFT) calculations are performed to characterize geometric and electronic features of the octahedral Al n N n and Al n P n cages (n = 12, 16, 28, 32, and 48). Toward this aim, 15N, 27Al, and 31P chemical shielding (CS) tensors as well as natural charge analyses are calculated for the optimized structures. CS parameters detect three distinct electronic environments for atoms within the Al n N n and Al n P n cages. The chemical shifts of N2 sites belonging to a hexagon and surrounded by three hexagons and a square obtained are different from those of N3 sites belonging to a hexagon that is surrounded only by hexagons—due to different curvatures exerted at the sites with different local structures. In addition, there is an increasing tendency in the Δσ values of the three local structures, Δσ (N1) > Δσ (N2) > Δσ (N3), N1 sites belonging to four-membered rings. The chemical shieldings of those Al and P sites belonging to a hexagon that is surrounded only by hexagons in the cages (360.7–366.7 and 496.5–514.7 ppm) are close to those previously reported for AlP nanotubes. Three distinct electrostatic environments around the N, Al, and P nuclei are also confirmed by the calculated natural charges. It should be noted that the positively charged Al atoms on the cages turn out to be the available sites for adsorption of H2 molecules. 相似文献
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Ali Reza Mahdavian Mahdi Abdollahi Leila Mokhtabad Farshid Ziaee 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(10):1583-1596
Many reports exist in the literature about the application of 1H and 13C‐NMR techniques to analyze the copolymer structure and composition and also determination of reactivity ratios. In this work, on‐line 1H‐NMR spectroscopy has been applied to identify reactivity ratios of itaconic acid and acrylonitrile in the solution phase (DMSO as the solvent) and in the presence of AIBN as the radical initiator. All the peaks corresponding to the existing protons were assigned quietly. Therefore, the kinetics of the copolymerization reaction was investigated by studying the variation of integral of two characteristic peaks regarding each monomer. The obtained data were used to find the reactivity ratios of acrylonitrile and itaconic acid by linear least‐squares methods such as Finemann‐Ross, inverted Finemann‐Ross, Mayo‐Lewis, Kelen‐Tudos, extended Kelen‐Tudos and Mao‐Huglin. In addition, a non‐linear least‐square method (Tidwell‐ Mortimer) was used at low conversions. Extended Kelen‐ Tudos and Mao‐Huglin were applied to determine reactivity ratio values at high conversions as well. 相似文献
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Electron-rich aromatic compounds react with formaldehyde and a secondary amine under solvent-free condition, in the presence of acidic alumina in a commercial microwave oven or at room temperature to produce aminomethylated products in good to excellent yields. 相似文献
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