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81.
Hassan M. Faidallah Salem A. Basaif Essam M. Sharshira Abd El-Kader A-Ba-Oum 《Phosphorus, sulfur, and silicon and the related elements》2013,188(3):671-683
Several urea and thiourea derivatives ( 2a-f ) were prepared by the reaction of dihydronaphthopyrazolylbenzenesulfonamide ( 1 ) with the corresponding isocyanates and isothiocyanates, respectively. The benzenesulfonylthioureas ( 2d , e ) were cyclized with ethyl bromoacetate, ethyl g -bromopropionate and f -bromoacetophenones to give the corresponding 4-oxothiazolidine ( 3a , b ), 4-oxo-5,6-dihydrothiazine ( 4a , b ) and thiazoline derivatives ( 5a-d ) respectively. 相似文献
82.
Essam Kh. Ahmed 《Phosphorus, sulfur, and silicon and the related elements》2013,188(5):1323-1336
Diethyl 2-isothiocyanato-4,5,6,7-tetrahydrothieno[2,3-c]pyridine-3,6 dicarboxylate 1 is a convenient and useful starting matrial for the constructions of heterocyclic systems. It was utilized to synthesize derivatives of the novel heterocyclic systems pyrido[4',3':4,5]thieno[2,3-d]pyrimidine 4 , 10 , pyrido[4',3':4,5]thieno[2,3-d]-[1,2,4]triazolo[1,5-a]pyrimidine 7 , 11a-e and pyrido[4',3':4,5]thieno[2,3-d][1,3,4]thiadiazolo[3,2-a]pyrimidine 12-14 . 相似文献
83.
Fawzy A. El Yazbi Ekram M. Hassan Essam F. Khamis Mohamed M. A. Hamdy 《液相色谱法及相关技术杂志》2016,39(19-20):869-876
Validated and selective high-performance thin-layer chromatography (HPTLC) method was developed for the determination of ketorolac tromethamine (KTC), phenylephrine hydrochloride (PHE), and chlorpheniramine maleate (CPM) in bulk drug and in combined dosage form. The proposed method depends on using HPTLC for separation of the drugs followed by densitometric measurements of their spots at 261?nm. The separation was carried out on Merck HPTLC aluminum sheets of silica gel 60 F254 using chloroform–methanol–ammonia (7.75:2.25:0.1, v/v) as mobile phase. Linear regression lines were obtained over the concentration ranges 0.12–0.50, 0.075–0.27, and 0.09–0.27?µg band?1 for KTC, PHE, and CPM, respectively, with correlation coefficients higher than 0.999. The method was successfully applied to the analysis of the three drugs in their synthetic mixtures and in their dosage form. The mean percentage recoveries were in the range of 98–102% with percentage relative standard deviation values less than 2%. The method was validated according to ICH guidelines and showed good performances in terms of linearity, precision, accuracy, sensitivity, and stability. 相似文献
84.
Essam Mohamed Sharshira Satoru Shimada Mutsuo Okamura Eietsu Hasegawa Takaaki Horaguchi 《Journal of heterocyclic chemistry》1996,33(6):1797-1805
Photocyclization reactions were carried out on 2-alkoxybenzophenones 1a-h and ethyl 2-benzoylphenoxyacetates 2a -e in acetonitrile. Irradiation of 1a-h gave dihydrobenzofuranols 4a-h in 68–84% yields. Similarly, irradiation of 2a-e afforded dihydrobenzofuranols 8a-e in 72–75% yields. Ethyl acrylates 9b-c were also produced in 6–8% yields from photoreactions of 2b-c . Substituent effects on cyclization of 1,5-biradical intermediates and reaction pathways are discussed. Benzophenones are useful compounds to prepare dihydrobenzofuranols by photocyclization. 相似文献
85.
86.
87.
Maher F. El-Zohry Thanaa A. Mohamed Essam M. Hussein 《Monatshefte für Chemie / Chemical Monthly》2009,140(3):265-272
Abstract 2-Methylbenzimidazole 1 reacted with 3-dicyanomethylidine-1-ethyl-2-oxoindoline 2 in ethyl acetate to afford 1-amino-2-cyano-3,4-dihydro-1′-ethylspiro{benzimidazo[1,2-a]pyridine-3,3′-indolin}-2′-one 6, which was used as a key intermediate in the synthesis of fused spiropolyheterocyclic derivatives of benzimidazopyridopyrimidine
and/or benzimidazonaphthyridine nucleus incorporating an indoline moiety.
Graphical abstract
相似文献
88.
Essam R. Shaaban Ishu Kansal M. Shapaan José M. F. Ferreira 《Journal of Thermal Analysis and Calorimetry》2009,98(2):347-354
This paper presents the results of kinematical studies of glass transition and crystallization in glassy Se85?x Te15Sb x (x = 2, 4, 6 and 8) using differential scanning calorimetry (DSC). From the dependence on heating rates of, the glass transition temperatures (T g), and temperature of crystallization (T p) the activation energy for glass transition (E g) and the activation energy for crystallization (E c) are calculated and their composition dependence can be discussed in term of the average coordination number and cohesive energy. The thermal stability of Se85?x Te15Sb x was evaluated in terms of criterion ΔT = T c ? T g and kinetic criteria K(T g) and K(T p). By analyzing the crystallization results, the crystallization mechanism is characterized. Two (two- and three-dimensional growth) mechanisms are working simultaneously during the amorphous–crystalline transformation of the Se83Te15Sb3 alloy while only one (three-dimensional growth) mechanism is responsible for the crystallization process of the chalcogenides Se85?x Te15Sb x (x = 4, 6 and 8) glass. The phases at which the alloy crystallizes after the thermal process have been identified by X-ray diffraction. 相似文献
89.
Ahmed M. El-Agrody Heba K. Abd El-Mawgoud Ahmed M. Fouda Essam S. A. E. H. Khattab 《Chemical Papers》2016,70(9):1279-1292
A series of 2-amino-4H-benzo[h]chromene and 2,7-diamino-4H-benzo[h]chromene derivatives were prepared as potential cytotoxic agents. The structures of the synthesised compounds were established on the basis of spectral data. The in-vitro cytotoxic activity of the synthesised compounds against the cell lines MCF-7, HCT-116 and HepG-2 was investigated in comparison with vinblastine and colchicine, using an MTT colorimetric assay. The structure-activity relationship of 4H-benzo[h]chromenes with modification at the 3-, 4- and 7-positions was explored. The results of the anti-tumour evaluation revealed that compounds VIIIc, VIId, VIIb, VIIe, VIIIg and VIIIc, VIId, VIIb, VIIe, VIIIg, VIIc, VIIIe, Vf, IIIa inhibited the growth of MCF-7 in comparison with vinblastine and colchicine, while VIIb, VIId, VIIe, IIIa, VIIa, VIIIc, VIIc, IIId, IIIg, IIIf, IIIb, IIIh, VIIIb, VIIIa, VIIIe, IIIc, Vg, IIIe, VIIIg, Vf, IIIf inhibited the growth of HCT-116 in comparison with colchicine. In addition, compounds VIIe, IIIg, IIIa, VIIc and VIIe, IIIg, IIIa, VIIc, VIIb, VIIa, VIIIf, VIIIe inhibited the growth of HepG-2 in comparison with vinblastine and colchicine, respectively. 相似文献
90.
Thirty-six new N,N'-disubstituted thioureas have been synthesized by the reaction of phenyl-, p-fluorophenyl- and benzoylisothiocyanates with various substituted anilines, aminopyridines and 4-aminoquinolines. The uv, ir and nmr spectral data are presented and discussed. 相似文献