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71.
A new series of 6,8-dibromo-2-(4-chlorophenyl)quinazolin-4(3H)-one derivatives VI–XIII were synthesized. Their chemical structures were confirmed by spectral and elemental analysis. The cytotoxic effect of the newly synthesized compounds was tested in vitro against human breast cancer cell line (MCF-7). Most of the tested compounds have shown promising cytotoxic activity. Compounds X and XIIIb exerted a powerful cytotoxic effect against MCF-7 with a very low IC50 (0.0015 and 0.0047 µmol/ml), while compounds VI, VII, VIII, XIIb, XI, XIIIc and IX exerted a moderate cytotoxic effect (IC50 0.01523, 0.0213, 0.031, 0.0478, 0.049, 0.068 and 0.079 µmol/ml respectively), compared to doxorubicin (0.0025 µmol/ml). Exploring their apoptotic effect; interestingly,all compounds activated apoptotic cascade in MCF-7. Compounds VI, XIIIb, XIIb, XI, XIIa, VII, V and VIII showed potent effect even much more than doxorubicin by 12.87–5.91 folds, while compounds XIIIc, IX, XIIIa, XIIc and X showed moderate increase in CASP3 activity by 4.96–3.22 folds relative to untreated cells more or less similar to doxorubicin (5.57 folds). 相似文献
72.
The best alternative to fight against corrosion is the use of an inhibitor, the purpose of this work is the formulation of a new biomass-based molecule against corrosion of carbon steel. Lignin was extracted using the Kraft process and phenylhydrazine molecules have been scratched. The influence of the lignin-phenylhydrazone(LP) on the corrosion of carbon steel in salt and the acidic medium was studied by the polarization resistance, the potentiodynamic polarization, and the electrochemical impedance spectroscopy. The results of these tests reveal that the behavior of the inhi-bitor is a mixed type. The adsorption mechanism of the inhibitor follows the Langmuir isothermal model. Gibbs energy shows that the process of inhibition of carbon steel is spontaneous. The SEM confirms that the inhibitor reduces the corrosion of the steel and stops the corrosion pitting phenomenon. The modified lignin shown as a good corrosion inhibitor in acid medium is highly saline with an efficiency> 96%. 相似文献
73.
Amel Boudjemaa Aline Auroux Souhila Boumaza Mohamed Trari Ouiza Cherifi Rabah Bouarab 《Reaction Kinetics and Catalysis Letters》2009,98(2):319-325
The effect of the structure of the achiral primary amine additive on the enantioselective heterogeneous catalytic hydrogenation
of (E)-2-methyl-2-butenoic acid over cinchonidine modified Pd/Al2O3 was studied. It was found that a variety of amines increase the enantioselectivity, which was always accompanied by decrease
in the initial rate of the hydrogenations. Based on these results, the participation of the amine additive in the formation
of the intermediate complex responsible for enantioselection was suggested. A decrease in the reaction temperature resulted
in further increase in the optical purity of the product up to 67%, the highest value reported in the hydrogenation of unsaturated
aliphatic acids in this heterogeneous catalytic system so far. 相似文献
74.
Romain Lucas Amel Hadj Bouazza Robert Granet Yves Champavier 《Tetrahedron letters》2008,49(6):1004-1007
Synthesis of a triazole-linked 3′-5′ thymidine dimer making use of 1,3-dipolar cycloaddition is described. The azido-precursor was obtained by regioselective chlorination of thymidine, followed by azidation. The second precursor, a propargyl derivative, was obtained by selective 3′-O-alkylation of thymidine. Two ‘click systems’ were compared to obtain the desired dimer. These reactions were performed by microwave irradiation. 相似文献
75.
Seven new diterpenes, featuring the rare 2,6-cyclo-xenicane skeleton, along with eleven previously reported metabolites were isolated from the organic extracts of the brown algae Dilophus fasciola and Dilophus spiralis. The structure elucidation of the isolated natural products was based on detailed analyses of their spectroscopic data (NMR, MS, IR, UV), whereas the assignment of their relative configurations was assisted by molecular modelling studies. 相似文献
76.
Ramyah F. Radman Amel M. Ismail Nada A. Al-Jallal 《Journal of Saudi Chemical Society》2010,14(2):223-229
The kinetics of amide bond cleavage of isatin and N-methylisatin in the presence of N,N-dimethylacetamide (DMA) was followed spectrophotometrically in the range of solvent composition (0–48.53 wt.%) and temperatures (40–70 °C) using piperidine as a nucleophile. The reaction was studied under pseudo-first-order kinetics. The rate of the reaction decreases largely with increasing organic solvent content. The thermodynamic activation parameters were calculated and discussed in terms of solvation of the activated complex. No linearity was observed between log rate constant and the reciprocal dielectric constant for the solvent used suggesting that there is a selective solvation by higher polar solvent (water). Finally, a mechanism for the ring opening for isatin and N-methylisatin was proposed. 相似文献
77.
Strontium fluorbritholites with the general formula Sr10-xNdx(PO4)6-x(SiO4)xF2 (0 ≤ x ≤ 6), were prepared by solid state reaction at temperatures between 1200 and 1400 °C. The XRD analysis showed that a pure apatitic phase was formed only for x ≤ 2.5. Above this value, there was formation of secondary phases. The variation of the lattice parameters as a function of x indicated that the formed solid solution was discontinuous on both sides of x = 3. The analysis by Raman and IR spectroscopies confirmed the incorporation of SiO4 groups within the apatite lattice, and showed that this incorporation induced in the structure a disorder that increased with increasing content of Nd3+ and SiO44−. Optical absorption measurements showed a wide variation in the local environment of Nd3+ ions, corresponding to the existence of new spectroscopic sites, evidenced by a luminescence study. 相似文献
78.
Najah Cheriaa Mouna Mahouachi Amel Ben Othman Lassaad Baklouti Yang Kim Rym Abidi 《Supramolecular chemistry》2013,25(3):265-271
A new family of hyperbranched molecules and dendrimers has been constructed from a diamide–dicalix derivative prepared from monocarbomethoxymethyl p-tert-butyl calix[4]arene and tris(2-aminoethyl)amine (‘tren’) via amide-formation reactions. The selective 1,3-di-O-functionalization of p-tert-butyl calix[4]arene moieties allows the synthesis of first- (G1) and second-generation (G2) calix-dendrimers. Replacement of the quadridentate amine by a trithia-ether-triamine-mono-ol, ’hyten’, again results in acylation of the amino groups, but with the generation of a central cavity with different complexing properties. A new family of hyperbranched molecules and dendrimers has been constructed from a diamide–dicalix derivative prepared from monocarbomethoxymethyl p-tert-butyl calix[4]arene and tris(2-aminoethyl)amine (‘tren’) via amide-formation reactions. The selective 1,3-di-O-functionalization of p-tert-butyl calix[4]arene moieties allows the synthesis of first- (G1) and second-generation (G2) calix-dendrimers 相似文献
79.
Mohamed El Amine Dib Hocine Allali Amel Bendiabdellah Nawel Meliani Boufeldja Tabti 《Journal of Saudi Chemical Society》2013,17(4):381-385
In this study, antimicrobial activities of water and methanol extract, and three phenolic fractions of the roots of Arbutus unedo L. were investigated. Poor antibacterial activity against both Staphylococcus aureus and Pseudomonas aeruginosa bacteria was shown with water and methanol extract. However moderate antibacterial activity was shown by water extract and phenolic fractions against Escherichia coli and S. aureus, respectively. The phytochemical screening of roots of A. unedo revealed the presence of quinones, anthraquinones reducteurs compounds, anthocyanins, tannins and flavonoids. Quantitative analysis showed that the roots were strongly dominated by anthocyanins compounds (3.65 mg g?1) followed by total flavonoids (0.56 mg?1) and flavones & flavonols (0.17 mg g?1). 相似文献
80.
T. O. Denisova E. V. Amel’chenkova I. S. Kislina N. B. Librovich S. E. Nefedov 《Russian Journal of Inorganic Chemistry》2006,51(11):1755-1762
3,5-Dimethylpyrazole complexes with HCl (an 1 : 1 complex) and trifluoromethanesulfonic acid (1 : 1 and 2 : 1 complexes) were structurally studied using X-ray crystallography. 相似文献