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91.
Joseph Genin Hatem Radwan 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》1970,21(6):983-990
Zusammenfassung Die bei Querschwingungen schlanker Stäbe mit zeitabhängiger Längsbelastung in der Bewegungsdifferentialgleichung auftretenden nichtlinearen Trägheitsterme, herrührend von der Longitudinalbewegung, werden hier im Gegensatz zu früheren Arbeiten mitberücksichtigt. Die sich daraus ergebenden nichtlinearen Korrekturen der Eigenfrequenzen des entsprechenden linearen Systems werden abgeschätzt. 相似文献
92.
Synthesis and Molecular Docking Studies of Novel 2‐Phenyl‐4‐Substituted Oxazole Derivatives as Potential Anti‐cancer Agents 下载免费PDF全文
Ahmed O. H. El‐Nezhawy Ahmad Farouk Eweas Mohamed A. A. Radwan Tarek B. A. El‐Naggar 《Journal of heterocyclic chemistry》2016,53(1):271-279
A novel series of 2,4‐disubstituted oxazole derivatives were synthesized, screened for their anti‐tumor activity against three cell lines MCF‐ 7 , TK‐10, and UACC‐62. Molecular docking study was carried out against epidermal growth factor receptor. A new series of 2‐phenyl‐4‐substituted oxazole derivatives were synthesized. A series of chiral α‐amino acid derivatives 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 were synthesized by coupling various l ‐acylated amino acid azide 3. The synthesized compounds were tested for their in vitro antitumor activity against MCF‐7, TK‐10, and UACC‐62 cell lines. Compound 6 exhibited the strongest inhibitory activity against TK cell lines, while compound 12 showed the highest activity against MCF‐7 cell lines. Compound 14 was the most active against UACC‐62 cell lines. Furthermore, a molecular docking study of the most active compounds was carried out using epidermal growth factor receptor X‐ray 3D structure (protein data bank ID 1 M17). Docking results revealed that compound 6 showed the highest binding energy of ΔG = ?78.17 Kcal/mol. 相似文献
93.
H. Jaskólska L. Rowińska L. Waliś M. Radwan 《Journal of Radioanalytical and Nuclear Chemistry》1973,13(1):41-52
The previously elaborated methods of the determination of As, Sc, La, Au, W, Mo, Ga and In have been adapted to the analysis
of steel. Samples of Armco steel taken from three various points of a steel bar section were analysed. On the basis of the
results obtained the distribution of the elements determined along the steel bar section is discussed. 相似文献
94.
Some new pyridazinone derivatives(3) were synthesized through addition of antipyrin to β-aroylacrylic acids (1) followed by cyclization of the adducts. Reactions of 3 with ethyl bromoacetate, benzenesulfonyl chloride, benzoyl chloride and POCl3 give N-substituted products and monochlorosubstituted pyridazines (4), respectively. The reactions of the latter with thiourea give unexpected dithio-derivatives (5), which react with phenylhydrazine to give pyrazolopyridazino pyridazine derivatives (6). Reactions of 2 with NH2OH in ethanol and pyridine afford oxime and oxazinone derivatives 7 and 8, respectively. The antibacterial activities of several compounds were screened. 相似文献
95.
A potentiometric lipoate-selective sensor based on mercuric lipoate ion-pair as a membrane carrier is reported. The electrode was prepared by coating the membrane solution containing PVC, plasticizer, and carrier on the surface of graphite electrode. Influences of the membrane composition, pH, and possible interfering anions were investigated on the response properties of the electrode. The sensor exhibits significantly enhanced response toward lipoate ions over the concentration range 1 × 10−7 mol L−1 to 1 × 10−2 mol L−1 with a lower detection limit of (LDL) of 9 × 10−8 mol L−1 and a slope of −29.4 mV decade−1, with S.D. of the slope is 0.214 mV. Fast and stable response, good reproducibility, long-term stability, applicability over a pH range of 8.0–9.5 is demonstrated. The sensor has a response time of ≤12 s and can be used for at least 6 weeks without any considerable divergence in its potential response. The proposed electrode shows good discrimination of lipoate from several inorganic and organic anions. The CGE was used in flow injection potentiometry (FIP) and resulted in well defined peaks for lipoate ions with stable baseline, excellent reproducibility and reasonable sampling rate of 30 injections per hour. The proposed sensor has been applied for the direct and FI potentiometric determination of LA in pharmaceutical preparations and urine; and has been also utilized as an indicator electrode for the potentiometric titration of LA. 相似文献
96.
Bejjani Alice Sidaoui Radwan Roumié Mohamad Darwish Talal Nsouli Bilal 《Journal of Radioanalytical and Nuclear Chemistry》2017,314(3):1885-1895
Journal of Radioanalytical and Nuclear Chemistry - This work presents a method for simultaneous proton induced gamma-ray emission analysis of fluorine, lithium, and sodium in “as... 相似文献
97.
The reaction of 3‐amino‐4,6‐dimethylthieno[2,3‐b]pyridine‐2‐carboxamide (1a) or its N‐aryl derivatives 1b‐d with carbon disulphide gave the pyridothienopyrimidines 2a‐d , whilst when the same reaction was carried out using N1‐arylidene‐3‐amino‐4,6‐dimethylthieno[2,3‐b]pyridine‐2‐carbohydrazides (1e‐h) , pyridothienothiazine 3 was obtained. Also, refluxing of 1b‐d with acetic anhydride afforded oxazinone derivative 4 . Compounds 2a and 2b‐d were also obtained by the treatment of thiazine 3 with ammonium acetate or aromatic amines, respectively. When compound 2a was allowed to react with arylidene malononitriles or ethyl α‐cyanocinnamate, novel pyrido[3″,2″:4′,5′]thieno[3′,2′:4,5]pyrimido[2,1‐b][1,3] thiazines 5a‐c were obtained. Treatment of 2b‐d with bromine in acetic acid furnished the disulphide derivatives 6a‐c . U.V. irradiation of 2b‐d resulted in the formation of pyrido[3″,2″:4′,5′]thieno[3′,2′:4,5]pyrimido[2,1‐b]benzthiazoles 7a‐c . The reaction of 2a‐d with some halocarbonyl compounds afforded the corresponding S‐substituted thiopyrido thienopyrimidines 8a‐j . Compound 8b was readily cyclized into the corresponding thiazolo[3″,2″‐a]‐pyrido[3′,2′:4,5]thieno[3,2‐d]pyrimidine 9 upon treatment with conc. sulphuric acid. Heating of 2a,b with hydrazine hydrate in pyridine afforded the hydrazino derivatives 11a,b . Reaction of ester 8c with hydrazine hydrate in ethanol gave acethydrazide 10 . Compounds 10 and 11a,b were used as versatile synthons for other new pyridothienopyrimidines 12–15 as well as [1,2,4] triazolopyridothienopyrimidines 16–19. 相似文献
98.
Donia A. M. Radwan N. R. E. Atia A. A. 《Journal of Thermal Analysis and Calorimetry》2000,61(1):249-261
Mixed oxides were prepared by the thermal decomposition of the oxalates of cobalt(II) and copper(II) coprecipitated from aqueous
solution or made by mechanical mixing. The compositions and structures of the oxides were confirmed by means of TG and X-ray
powder diffraction spectroscopy. The catalytic behaviour of the oxides obtained was studied by using the decomposition of
H2O2 as a model reaction. The results were compared with those on the oxides produced from the thermal decomposition of mechanically
mixed oxalates. The catalytic activities of the mixed oxides were found to be lower than that of pure cobalt oxide, but higher
than that of copper oxide. This result was interpreted in terms of the relative standard reduction potential of the catalyst
as compared with that of H2O2. The catalytic activity of the mixed oxides obtained from the coprecipitate was found to be lower than that of the oxides
obtained from the mechanical mixture at the same temperature. As the temperature of preparation was increased, the catalytic
activities of the oxides obtained decreased. This was attributed to the solid-solid interactions, which gave a new phase with
lower catalytic activity than those of the interacting phases.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
99.
Usama W. Hawas Lamia T. Abou El-Kassem Fekri M. Shaher Radwan Al-Farawati Mohamed Ghandourah 《Molecules (Basel, Switzerland)》2022,27(11)
The aim of this study was to determine the compositions of carbohydrates, phenolic compounds, fatty acids (FAs), and amino acids (AAs) of four Rea Sea halophytes: Anabasis ehrenbergii, Suaeda aegyptiaca, Suaeda monoica, and Zygophyllum album. The results showed that S. aegyptiaca and S. monoica were rich in gallic acid with 41.72 and 47.48 mg/g, respectively, while A. ehrenbergii was rich in naringenin with 11.88 mg/g. The polysaccharides of the four species were mainly composed of galactose (54.74%) in A. ehrenbergii, mannose (44.15%) in S. aegyptiaca, glucose and ribose (33 and 26%, respectively) in S. monoica, and arabinose and glucose (36.67 and 31.52%, respectively) in Z. album. Glutamic acid and aspartic acid were the major AAs in all halophyte species with 50–63% and 10–22% of the total AAs, respectively. The proportion of unsaturated fatty acids (UFA) of the four species was 42.18–55.33%, comprised mainly of linolenic acid (15.54–28.63%) and oleic acid (5.68–22.05%), while palmitic acid (23.94–49.49%) was the most abundant saturated fatty acid (SFA). Phytol and 9,19-cyclolanost-24-en-3β–ol represented the major unsaponifiable matter (USM) constituents of S. monoica and A. ehrenbergii with proportions 42.44 and 44.11%, respectively. The phenolic fraction of S. aegyptiaca and S. monoica demonstrated noteworthy antioxidant activity with IC50 values of 9.0 and 8.0 μg/mL, respectively, while the FAs fraction of Z. album exhibited potent cytotoxic activity against Huh-7, A-549, and Caco-2 cancer cell lines with IC50 values of 7.4, 10.8, and 11.8 μg/mL, respectively. Our results indicate that these plants may be considered a source of naturally occurring compounds with antioxidant and anticancer effects that could be suitable for future applications. 相似文献
100.
A. M. Radwan 《Crystal Research and Technology》1988,23(6):785-791
Energy bands of BCC rubidium and cesium are calculated for the first time using the full non-local but energy-independent Shaw's optimized model potential. The energy dependence of the potential is then included as first order perturbation. The effects of changing the model potential and of reversing the sign of the depletion charge d are reported. The Fermi energy EF is calculated in all cases. Our results are compared with those obtained by other authors. The band gap at N is very small for both metals, except when all model potential parameters are increased considerably (50% to 100%). 相似文献