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排序方式: 共有265条查询结果,搜索用时 31 毫秒
101.
Russian Journal of General Chemistry - A series of new 1-{[1-(3-chlorophenyl)-3-(4-methoxyphenyl)-1H-pyrazol-4-yl]methyleneamino}-6-amino-1,2-dihydro-4-(substitutedphenyl)-2-oxopyridine-3,5-di... 相似文献
102.
Let R be an integral domain. We say that R is a star-domain if R has at least a height one prime ideal and if for each height one prime ideal P of R, R satisfies the acc on P-principal ideals (i.e., ideals of the form aP, a ∈ R). We prove that if R is an APVD with nonzero finite Krull dimension, then the power series ring R[[X]] has finite Krull dimension if and only if R is a residually star-domain (i.e., for each nonmaximal prime ideal P of R, R/P is a star-domain) if and only if R[[X]] is catenarian. 相似文献
103.
104.
Ahmed O. H. El Nezhawy Mostafa M. Ramla Nagy M. Khalifa Mohamed M. Abdulla 《Monatshefte für Chemie / Chemical Monthly》2009,38(5):531-539
Abstract 4-Fluorobenzaldehyde was used for the preparation of 2-(4-fluorophenyl)thiazolidin-4-one derivatives which were allowed to
react with chloroacetonitrile and acrylonitrile to produce 3-(2-(4-fluorophenyl)-4-oxothiazolidine3-yl)acetonitrile and 3-(2-(4-fluorophenyl)-4-oxothiazoledine-3-yl)propanenitrile.
Biological evaluation of some of the compounds showed that many had promising antioxidant activity.
Graphical Abstract
相似文献
105.
Khalifa N. M. Alkahtani H. M. Al-Omar M. A. Bakheit A. H. 《Russian Journal of General Chemistry》2019,89(8):1683-1690
Russian Journal of General Chemistry - A new series of pyrido[2,3-d]pyrimidones incorporated pyrazoles and fused triazoles are synthesized and tested in vitro for cytotoxic effect against cancer... 相似文献
106.
S. Ben Khalifa B. Gruzza G. Bremond F. Saidi L. Bèji 《Journal of luminescence》2008,128(10):1611-1616
Porous GaAs layers were formed by electrochemical etching of p-type GaAs(1 0 0) substrates in HF solution. A surface characterization has been performed on p-type GaAs samples using X-ray photoelectron spectroscopy (XPS) technique in order to get information about the chemical composition, particularly on the surface contamination. According to the XPS spectra, the oxide layer on as-received porous GaAs substrates contains As2O3, As2O5 and Ga2O3. Large amount of oxygen is present at the surface before the surface cleaning.Compared to untreated GaAs surface, room temperature photoluminescence (PL) investigations of the porous layers reveal the presence of two PL bands: a PL peak at ∼871 nm and a “visible” PL peak at ∼650-680 nm. Both peak wavelengths and intensities varied from sample to sample depending on the treatment that the samples have undergone. The short PL wavelength at 650-680 nm of the porous layers is attributed to quantum confinement effects in GaAs nano-crystallites. The surface morphology of porous GaAs has been studied using atomic force microscopy (AFM). Nano-sized crystallites were observed on the porous GaAs surface. An estimation of the mean size of the GaAs nano-crystals obtained from effective mass theory and based on PL data was close to the lowest value obtained from the AFM results. 相似文献
107.
Ibrahim H. Eissa Mohamed M. Khalifa Eslam B. Elkaeed Elsayed E. Hafez Aisha A. Alsfouk Ahmed M. Metwaly 《Molecules (Basel, Switzerland)》2021,26(20)
In continuation of our previous effort, different in silico selection methods were applied to 310 naturally isolated metabolites that exhibited antiviral potentialities before. The applied selection methods aimed to pick the most relevant inhibitor of SARS-CoV-2 nsp10. At first, a structural similarity study against the co-crystallized ligand, S-Adenosyl Methionine (SAM), of SARS-CoV-2 nonstructural protein (nsp10) (PDB ID: 6W4H) was carried out. The similarity analysis culled 30 candidates. Secondly, a fingerprint study against SAM preferred compounds 44, 48, 85, 102, 105, 182, 220, 221, 282, 284, 285, 301, and 302. The docking studies picked 48, 182, 220, 221, and 284. While the ADMET analysis expected the likeness of the five candidates to be drugs, the toxicity study preferred compounds 48 and 182. Finally, a density-functional theory (DFT) study suggested vidarabine (182) to be the most relevant SARS-Cov-2 nsp10 inhibitor. 相似文献
108.
The acid-base properties of Brilliant Green and Solochrome Red B have been studied in an attempt to apply them as metallochromic or chromophoric indicators. The thermodynamic pK values 4.93 and 2.62 corresponding to the ionization of the hydrogen sulfate group and to the protonation of the second diethylamino group in Brilliant Green, and 3.46, 5.80, 7.22, and 13.30 corresponding to the ionization of the two sulfonic, the carboxylic, and the phenolic groups in Solochrome Red B, respectively, were computed from results of potentiometric and spectrophotometric measurements. 相似文献
109.
The paper reports measurements of the viscosity of normal butane and isobutane at atmospheric pressure in the temperature range 25–195°C. In addition, the viscosity of mixtures of the two gases has been determined in the more limited temperature range 25–100°C. The absolute accuracy of the viscosity data is estimated as ±0.2%, whereas the ratio of the viscosity of the two pure components is determined with an uncertainty of ±0.1%. The viscosity data allow the evaluation of the diffusion coefficients for the n-butane-i-butane system.The experimental data demonstrate that there are discernible differences between the intermolecular potentials for the pair-interactions n-C6H10-n-C4H10; and i-C4H10-i-C4H10. All of the experimental data can be correlated within their experimental uncertainty with the aid of the extended law of corresponding states developed by Kestin, Ro and Wakeham. The optimum values of the two scaling parameters, σij and ?ij, for each interaction which secure this agreement are determined. 相似文献
110.
A general method for synthesis of folic acid, its conjugates and analogues . A new and general method for the synthesis of folic acid, folic acid conjugates and folic acid analogues is described. The key step, i.e. the condensation of N(2′)-acetyl-6-formyl-pterine (I: R1 ? COCH3) with aminoaryl derivatives II, is achieved by refluxing in absolute ethanol to afford the azomethines III. NaBH4-reduction followed by basic hydrolysis gives pure V products in high yield, free from 7-isomers. 相似文献