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41.
Ferdinand H. Lutter Lucie Grokenberger Philipp Spieß Jeffrey M. Hammann Konstantin Karaghiosoff Paul Knochel 《Angewandte Chemie (International ed. in English)》2020,59(14):5546-5550
A combination of 10 % CoCl2 and 20 % 2,2′‐bipyridine ligands enables cross‐coupling of functionalized primary and secondary alkylzinc reagents with various (hetero)aryl halides. Couplings with 1,3‐ and 1,4‐substituted cycloalkylzinc reagents proceeded diastereoselectively leading to functionalized heterocycles with high diastereoselectivities of up to 98:2. Furthermore, alkynyl bromides react with primary and secondary alkylzinc reagents providing the alkylated alkynes. 相似文献
42.
Ferdinand Tantangmo Bruno Ndjakou Lenta Silvre Ngouela Louis Marie Kamdem Bernard Weniger Etienne Tsamo Annelise Lobstein Catherine Vonthron‐Sncheau 《Helvetica chimica acta》2010,93(11):2210-2217
Phytochemical investigation of the bark and leaves of Pancovia laurentii (Sapindaceae) resulted in the isolation of a new ceramide and a new cerebroside, named pancoviamide ( 1 ), and pancovioside ( 2 ) respectively, together with six known compounds: uracil, (R)‐N‐[(1S,2S,3R)‐2,3‐dihydroxy‐1‐(hydroxymethyl)heptadec‐5‐en‐1‐yl]‐2‐hydroxytetracosanamide, stigmasta‐7,22‐dien‐3‐ol, β‐stitosterol, β‐sitosterol 3‐O‐β‐D ‐glucopyranoside, and 2,3‐dihydroxypropyl pentadecanoate. The structures of 1 and 2 were determined by means of spectroscopic methods. Compounds 1 and 2 were tested in vitro for their antiprotozoal properties against several protozoa and for their cytotoxicity. 相似文献
43.
Fraga R Zacconi F Sussman F Ordóñez-Morán P Muñoz A Huet T Molnár F Moras D Rochel N Maestro M Mouriño A 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(2):603-612
Based on the crystal structures of human vitamin D receptor (hVDR) bound to 1α,25-dihydroxy-vitamin D(3) (1,25 D) and superagonist ligands, we previously designed new superagonist ligands with a tetrahydrofuran ring at the side chain that optimize the aliphatic side-chain conformation through an entropy benefit. Following a similar strategy, four novel vitamin D analogues with aromatic furan side chains (3a, 3b, 4a, 4b) have now been developed. The triene system has been constructed by an efficient stereoselective intramolecular cyclization of an enol triflate (A-ring precursor) followed by a Suzuki-Miyaura coupling of the resulting intermediate with an alkenyl boronic ester (CD-side chain, upper fragment). The furan side chains have been constructed by gold chemistry. These analogues exhibit significant pro-differentiation effects and transactivation potency. The crystal structure of 3a in a complex with the ligand-binding domain of hVDR revealed that the side-chain furanic ring adopts two conformations. 相似文献
44.
In the above-mentioned paper, the total rate of generation is defined by
(unnumbered equation in Chapter 4.2 after Eq. (21)); in this equation the factor (1−cd+) is missing. As a consequence, Eqs. (22)–(30) and Fig. 4 in the original paper have to be revised which is presented in this corrigendum. Numbering of references remains unchanged. 相似文献
45.
A series of methyl hydronaphthyl alcohols, formates, acetates, and ketones were prepared and their odour properties evaluated. Minor structural changes, even opposite to the osmophoric group, were found to have major effects on the odour. 13C? NMR shift assignments of the hydronaphthyl derivatives are presented. 相似文献
46.
Spatial structures as a result of a modulational instability are obtained in the integrable discrete nonlinear Schrödinger equation (Ablowitz-Ladik equation). Discrete slow space variables are used in a general setting and the related finite differences are constructed. Analyzing the ensuing equation, we derive the modulational instability criterion from the discrete multiple scales approach. Numerical simulations in agreement with analytical studies lead to the disintegrations of the initial modulated waves into a train of pulses. 相似文献
47.
Milo? Luká? Ivan Lacko Marián Bukovsky Zuzana Kyselová Janka Karlovská Branislav Horváth Ferdinand Devínsky 《Central European Journal of Chemistry》2010,8(1):194-201
We synthesized nine quaternary ammonium compounds (QUATs) starting from phenylalanine, N-alkyl-N,N-dimethyl-(1-hydroxy-3-phenylpropyl)-2-ammonium bromides, which were prepared as optically pure substances. Five compounds
were prepared as S-enantiomers and four compounds as R-enantiomers. These compounds were evaluated by their activities against bacteria and fungi. Three microbial strains were
used in the study: the gram-negative bacteria Escherichia coli, the gram-positive bacteria Staphylococcus aureus and the fungi Candida albicans. The activities were expressed as minimum bactericidal or fungicidal concentrations (MBC). The most active compounds were
(2S)-N-tetradecyl-N,N-dimethyl-(1-hydroxy-3-phenylpropyl)-2-ammonium bromide and (2R)-N-tetradecyl-N,N-dimethyl-(1-hydroxy-3-phenylpropyl)-2-ammonium bromide, with MBC values exceeding those of commercial benzalkoniumbromide
(BAB) used as standard. The relationships between structure and biological activity of the tested QUATs were quantified by
the bilinear model (QSAR) and are discussed. 相似文献
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