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61.
R. L. Antipin A. N. Chernysheva E. K. Beloglazkina N. V. Zyk 《Chemistry of Heterocyclic Compounds》2010,46(9):1071-1075
The electrophilic sulfenylation of a series of indoles and pyrroles with arylsulfenamides in the presence of phophorus(V)
oxohalide has been studied. It has been shown that arylsulfenylation of indoles led to products with substitution at position
3, while in the case of pyrrole it occurred at position 2. 相似文献
62.
M. G. Voronkov A. A. Korlyukov É. A. Zelbst S. P. Knyazev I. M. Vasil rsev E. A. Chernyshev M. Yu. Antipin 《Journal of Structural Chemistry》2010,51(4):719-724
The crystal structures of anhydrous 1-germatranol and its complex with HCCl3 are centrosymmetrical dimers because of their intermolecular hydrogen bonds. In the germatranol crystal, the axial and equatorial
oxygen atoms of its two molecules are hydrogen bonded into an eight-membered coordination cycle. In the complex with HCCl3, the two molecules of germatranol are likewise linked in dimers, and both axial oxygen atoms are H bonded with HCCl3. In the investigated structures, the axial Ge—O bond is shorter than the equatorial ones. Depending on the number and strength
of the hydrogen bonds, the interatomic Ge—O and Ge ← N distances change markedly. The quantitative estimates of the H bond
energy are obtained from quantum chemical calculations of the model systems containing 1-germatranol and HCCl3 molecules. 相似文献
63.
A. G. Shipov S. V. Grüner A. A. Korlyukov E. P. Kramarova T. P. Murasheva S. Yu. Bylikin Vad. V. Negrebetskii F. A. Ivashchenko D. V. Airapetyan G. Ya. Zueva M. Yu. Antipin Yu. I. Baukov 《Russian Chemical Bulletin》2010,59(4):761-770
Reactions of GeBr4 with N,N-dimethyl-2-trimethylsiloxypropionamide (2a), (S)-2-trime-thylsiloxypropionpyrrolidide ((S)-2b), and N,N-dimethyl-O-(trimethylsilyl)mandelamide (2c) afforded pentacoordinated neutral (O,O)-monochelates, viz., N,N-dimethyl-2-tribromoger-myloxypropionamide (3a), (S)-2-tribromogermyloxypropionpyrrolidide ((S)-3b), and N,N-dimethyl-O-(tribromogermyl)mandelamide (3c), respectively. X-ray diffraction study was performed for tribromides 3a, (S)-3b, and 3c, as well as for the N,N-dimethylmandelamide (1c) described earlier. According to the X-ray diffraction data, the Ge atom in tribromides 3a, (S)-3b, and 3c is pentacoordinated and has trigonal bipyramidal configuration with two halogen atoms and oxygen atom of the ether group in the equatorial positions and the halogen atom and the amide oxygen atom in the axial fragment, the bonds in which are somewhat longer as compared to the analogous bonds in tetracoordinated Ge compounds. 相似文献
64.
Elena E. Zvereva Sergey A. Katsyuba Alexander E. Vandyukov Alla V. Chernova Valery I. Kovalenko Svetlana E. Solovieva Igor S. Antipin Alexander I. Konovalov 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2010,75(2):872-879
It is demonstrated that dissolution of aminothiacalix[4]arene in chloroform results in transformation of 1,3-alternate conformation, adopted in single-crystal and bulk polycrystalline solids, to the pinched-cone form. This conformer is stabilised by the intramolecular hydrogen bonds of two distal amino-groups acting as H-donors with another two amino moieties that appear as H-acceptors. The H-bonds cause quite small (ca. 10–20 cm?1) red shift of the IR bands of the NH2 stretching vibrations, which suggests rather weak NH?N hydrogen bonding. This latter is sufficient to stabilize the pinched-cone conformation in the chloroform solution, but the energy gap between the pinched-cone and other conformations is small, and solid-state intermolecular forces easily overcome it, leading to realisation of the 1,3-alternate conformer. The comparison of the DFT computed and experimental vibrational and NMR spectra demonstrates good quality of present quantum-chemical computations, allows complete interpretation of the spectra and reveals simple IR and NMR spectroscopic markers of the conformers of aminothiacalix[4]arenes. 相似文献
65.
Valentine P. Ananikov Prof. Konstantin A. Gayduk Nikolay V. Orlov Dr. Irina P. Beletskaya Prof. Victor N. Khrustalev Dr. Mikhail Yu. Antipin Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(7):2063-2071
The present study reports the evidence for the multiple carbon–carbon bond insertion into the metal–heteroatom bond via a five‐coordinate metal complex. Detailed analysis of the model catalytic reaction of the carbon–sulfur (C? S) bond formation unveiled the mechanism of metal‐mediated alkyne insertion: a new pathway of C? S bond formation without preliminary ligand dissociation was revealed based on experimental and theoretical investigations. According to this pathway alkyne insertion into the metal–sulfur bond led to the formation of intermediate metal complex capable of direct C? S reductive elimination. In contrast, an intermediate metal complex formed through alkyne insertion through the traditional pathway involving preliminary ligand dissociation suffered from “improper” geometry configuration, which may block the whole catalytic cycle. A new catalytic system was developed to solve the problem of stereoselective S? S bond addition to internal alkynes and a cost‐efficient Ni‐catalyzed synthetic procedure is reported to furnish formation of target vinyl sulfides with high yields (up to 99 %) and excellent Z/E selectivity (>99:1). 相似文献
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70.
Detailed study of the crystal packing of 8,9,10,12-tetrafluoro-o-carborane by the topological analysis of the electron density distribution function was performed and the competing between
the F...H and H...H interactions in the crystal was investigated. 相似文献