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排序方式: 共有265条查询结果,搜索用时 187 毫秒
91.
Karol Bukowski Beata Marciniak Mateusz Kciuk Mariusz Mojzych Renata Kontek 《Molecules (Basel, Switzerland)》2022,27(12)
In this paper, we present for the first time the evaluation of cytotoxicity and genotoxicity of de novo synthesized pyrazolo[4,3-e]tetrazolo[1,5-b][1,2,4]triazine sulfonamides MM129, MM130, and MM131 in human tumor cell lines: HeLa, HCT 116, PC-3, and BxPC-3. Cytotoxic and genotoxic properties of the tested compounds were estimated using the MTT assay, comet assay (alkaline and neutral version), and γ-H2AX immuno-staining. Examined sulfonamides exhibited strong anticancer properties towards tested cells in a very low concentration range (IC50 = 0.17–1.15 μM) after 72 h exposure time. The results of the alkaline and neutral version of the comet assay following 24 h incubation of the cells with tested compounds demonstrated the capability of heterocycles to induce significant DNA damage in exposed cells. HCT 116 cells were the most sensitive to the genotoxic activity of novel tricyclic pyrazolo[4,3-e]tetrazolo[1,5-b][1,2,4]triazine sulfonamides in the neutral version of the comet assay. Immunocytochemical detection of γ-H2AX showed an increase in DNA DSBs level in the HCT 116 cell line, after 24 h incubation with all tested compounds, confirming the results obtained in the neutral comet assay. Among all investigated compounds, MM131 showed the strongest cytotoxic and genotoxic activity toward all tested cell types. In conclusion, our results suggest that MM129, MM130, and MM131 exhibit high cytotoxic and genotoxic potential in vitro, especially towards the colorectal cancer cell line HCT 116. However, further investigations and analyses are required for their future implementation in the field of medicine. 相似文献
92.
93.
Mariola Sadej Ewa Andrzejewska Beata Kurc Hubert Gojzewski Teofil Jesionowski 《Journal of polymer science. Part A, Polymer chemistry》2014,52(24):3472-3487
Two types of silica: precipitated (P, prepared in non‐polar media, a new type, submicrometer sized) and fumed (F, nanosized), both unmodified and surface modified are investigated as functional fillers for potential applications in nanocomposites with poly(2‐hydroxyethyl methacrylate) matrix. Special attention is paid to the kinetics of composite formation in an in situ photopolymerization process. Silica‐containing formulations polymerize faster; this effect is much stronger for silica P having much larger particle size than silica F. Surface treatment leads to further acceleration of the polymerization in case of silica P but to retardation in case of silica F; the effect of modification of the filler surface on properties of composites is different for each of the silicas. The obtained results are discussed in terms of effects of curvature of silica particles, surface properties, solvation cell, interphase region, viscosity changes, and morphology of the resulting composites. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 3472–3487 相似文献
94.
Tatiana L. Zinenko Vladimir V. Yachin Marian Marciniak 《Optical and Quantum Electronics》2014,46(6):779-790
This paper is devoted to the study of the features of artificial gyrotropic magneto-dielectric layer with two-dimensional periodicity. Such a layer can be used in the development of the polarizers operating in the microwave and optical ranges. Analytical solution of a plane wave scattering from a double-periodic gyrotropic layer is obtained by the Method of Integral Functionals in the quasi-static approximation. The numerical results allow to realize the TE- and TM-pass Brewster’s angle polarizers. 相似文献
95.
Roberto Fernández de la Pradilla Alma Viso Sonia Castro Jorge Fernández Pilar Manzano Mariola Tortosa 《Tetrahedron》2004,60(37):8171-8180
The SN2′ displacement of readily available vinyl epoxy sulfoxides with organocopper reagents takes place in good yields with high anti selectivity and a good degree of E/Z stereocontrol to produce enantiopure α-hydroxy vinyl sulfoxides. A second allylic displacement on the related mesyloxy vinyl sulfoxides allows for the asymmetric construction of two adjacent chiral centers. In addition, cuprate mediated SN2′ addition to alkynyl epoxy sulfoxides affords α-hydroxy allenyl sulfoxides in good yields. 相似文献
96.
Lewinski J Zachara J Gos P Grabska E Kopec T Madura I Marciniak W Prowotorow I 《Chemistry (Weinheim an der Bergstrasse, Germany)》2000,6(17):3215-3227
The interaction of dioxygen with various tetrahedral aluminum alkyls, (tBu)3Al.OEt2 (1), tBu2Al(mu-OtBu)2AltBu2 (6), (tBu)2Al(mesal) (2) [mesal=methyl salicylate anion], R2Al(mu-pz)2AlR2 [pz=deprotonated pyrazole, R= Me (3a), Et (3b), and tBu (3c)], R2Al(mu-3,5-Me2pz)2AIR2[3,5-Me2pz = deprotonated 3,5-dimethylpyrazole, R= Me (4a), and Et (4b)], and Et2B(mu-pz)2AlEt2 (5), has been investigated. We were particularly interested in the effect of steric hindrances both caused by the metal-bonded substituents and those that result from the nature of the bifunctional ligand used in the oxygenation reaction. In the reaction of 1 with O2, only the formation of the monoalkoxide compound6 was observed. The latter di-tert-butyl compound as well as all planar aluminapyrazoles, that is, the tert-butyl derivative 3c and lower alkylaluminum derivatives with the more demanding 3,5-dimethylpyrazoyl ligands 4a and 4b, are stable under an atmosphere of dry oxygen and ambient conditions. Inspection of the space-filling representation of these compounds has undoubtedly shown that the bulky tert-butyl groups or pyrazolyles ligands, respectively, provide steric protection for the metal center from the dioxygen attack. In contrast, the dialkylaluminum derivatives of pyrazole, 3a and 3b, and the diethylaluminum bis(1-pyrazolyl)borate complex 5, all with the metal center eclipsed with respect to the plane defined by the four nitrogen atoms, react smoothly with O2 to form the alkyl(alkoxy)aluminum complexes. In the reaction of 5 with O2 for example, the Et-B bonds remained intact, and the dimeric five-coordinate compound [Et2B(mu-pz)2 Al(mu-OEt)Et]2 (9) was isolated in good yield. The interaction of mononuclear di-tert-butyl chelate complex 2 with O2 at -15 degrees C gives (tBuOO)(tBuO)Al(mu-OtBu)2Al(mesal)2 (7) in high yield, and the presence of the alkylperoxo moiety is a particularly significant point in the resulting product. All the compounds have been characterized spectroscopically, and the structures of 3c, 4a, 6, 7, and 9 have been confirmed by X-ray crystallography. Structural features of 1-6 are discussed and are considered in relation to the possible approach pathways of the O2 molecule to the four-coordinate metal center. This analysis and the observed apparent dissimilarity in the reactions of model four-coordinate aluminum alkyls with O2 clearly show that the stereoelectronic prerequisites are responsible for the fundamentally different reactivity. 相似文献
97.
[reaction: see text] The highly selective base-promoted cyclization of enantiopure sulfinyl dienols affords allylic sulfinyl dihydropyrans. 相似文献
98.
Chatłas Janusz Danilczuk Eleonora Nasiadko Mariola Raszkowska Teresa 《Transition Metal Chemistry》2002,27(3):346-351
The kinetics of acid-catalyzed hydrolysis of the [Co(en)(L)2(O2CO)]+ ion (L = imidazole, 1-methylimidazole, 2-methylimidazole) follows the rate law –d[complex]/dt = {k
1
K[H+]/(1 + K[H+])}[complex] (15–30 or 25–40 °C, [H+] = 0.1–1.0 M and I = 1.0 M (NaClO4)). The reaction course consists of a rapid pre-equilibrium protonation, followed by a rate determining chelate ring opening process and subsequent fast release of the one-end bound carbonato ligand. Kinetic parameters, k
1 and K, at 25 °C are 5.5 × 10–2 s–1, 0.44 M–1 (ImH), 5.1 × 10–2 s–1, 0.54 M–1 (1-Meim) and 3.8 × 10–3 s–1, 0.74 M–1 (2-MeimH) respectively, and activation parameters for k
1 are H1
= 43.7 ± 8.9 kJ mol–1, S1
= –123 ± 30 J mol–1 deg–1 (ImH), H1
= 43.1 ± 0.3 kJ mol–1, S1
= –125 ± 1 J mol–1 deg–1 (1-Meim) and H1
= 64.2 ± 4.3 kJ mol–1, S1
= –77 ± 14 J mol–1 deg–1 (2-MeimH). The results are compared with those for similar cobalt(III) complexes. 相似文献
99.
Bernard Marciniak 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(7):o419-o422
The asymmetric unit of the title compound, C10H8O2, contains two practically planar symmetry‐independent molecules linked by one O—H...O hydrogen bond. Molecules are further linked into a three‐dimensional network, which is built from R66(36), R66(18), R66(30) and R44(26) rings formed by the combined effect of three O—H...O and one C—H...O hydrogen bond. This network is additionally stabilized by an O—H...π interaction. 相似文献
100.
Jacek Skar?ewski Mariola Zielińska-B?ajetSzczepan Roszak Ilona Turowska-Tyrk 《Tetrahedron》2003,59(20):3621-3626
Optically active (3R,1RS)-3-aryl-1-phenyl-3-phenylsulfanyl-1-propanols were easily dehydrated forming mainly rac-cis-2-aryl-4-phenylthiochroman, and rac-cis-4-aryl-2-phenylthiochroman along with the corresponding trans-isomers. The observed reaction outcome (rearrangement and racemisation) apparently results from the SEAr reaction involving the unusual 1,3-phenylsulfanyl group migration. This interpretation is supported by the results of theoretical studies (DFT) on the supposed intermediates. 相似文献