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81.
82.
Paramathevar Nagaraj 《Tetrahedron letters》2009,50(27):3970-2532
Anhydrous InCl3 has been shown to efficiently catalyze the Ferrier rearrangement by a direct allylic substitution of the hydroxyl group at C-3 position of glycals to afford the corresponding 2,3-unsaturated glycosides in high yields at ambient temperature. This methodology obviates the need for protecting and/or activating the C-3 hydroxyl group of glycals. The reaction works in equal ease with both 4,6-di-O-benzyl-d-glucal and 4,6-di-O-benzyl-d-galactal. The mildness of InCl3 makes this approach compatible for glycosyl acceptors with acid labile groups. The generality of the reaction has been demonstrated with a diversity of alcohols, phenols, and sugar nucleophiles. 相似文献
83.
The electronic structure and the electron dynamics of the clean InAs(1 1 1)A 2 × 2 and the InAs(1 1 1)B 1 × 1 surfaces have been studied by laser pump-and-probe photoemission spectroscopy. Normally unpopulated electron states above the valence band maximum (VBM) are filled on the InAs(1 1 1)A surface due to the conduction band pinning above the Fermi level (EF). Accompanied by the downward band banding alignment, a charge accumulation layer is confined to the surface region creating a two dimensional electron gas (2DEG). The decay of the photoexcited carriers above the conduction band minimum (CBM) is originated by bulk states affected by the presence of the surface. No occupied states were found on the InAs(1 1 1)B 1 × 1 surface. This fact is suggested to be due to the surface stabilisation by the charge removal from the surface into the bulk. The weak photoemission intensity above the VBM on the (1 1 1)B surface is attributed to electron states trapped by surface defects. The fast decay of the photoexcited electron states on the (1 1 1)A and the (1 1 1)B surfaces was found to be τ1 1 1 A ? 5 ps and τ1 1 1 B ? 4 ps, respectively. We suggest the diffusion of the hot electrons into the bulk is the decay mechanism. 相似文献
84.
Glycals undergo smooth coupling with β-enaminoketones and β-enaminoesters generated in situ from 1,3-dicarbonyl compounds and arylamines in the presence of 10 mol % of InCl3 in refluxing dichloroethane to produce oxa-aza bicyclononene scaffolds in excellent yields with high selectivity. The use of InCl3 makes this protocol simple, convenient and easy to scale-up. 相似文献
85.
The reaction of allylindium reagents and N-(2-cyanoaryl)amides afforded 2-substituted-4-allylquinazolines in good yields via the indium-mediated Barbier-type allylation of nitrile and the following dehydrative cyclization cascade. 相似文献
86.
Bo Ram Park 《Tetrahedron letters》2010,51(50):6568-6571
An efficient synthesis of trans-α-methylene-γ-butyrolactones is disclosed from syn-homoallylic alcohols via the intramolecular mesylate displacement reaction promoted by nearby ester group under the influence of MsCl/Et3N. syn-Homoallylic alcohols were prepared via the In-mediated Barbier reaction of the bromides of Baylis-Hillman adducts. 相似文献
87.
Wenlong Yin Dajiang Mei Jiyong Yao Peizhen Fu Yicheng Wu 《Journal of solid state chemistry》2010,183(11):2544-2551
Two new ternary bismuth chalcogenides, Bi3In4S10 and Bi14.7In11.3S38, were synthesized from the reactions of binary sulfides via a two-step flux technique. Single-crystal X-ray diffraction analyses indicate that Bi3In4S10 crystallizes in the non-centrosymmetric space group Pm and Bi14.7In11.3S38 crystallizes in the centrosymmetric space group P21/m. Both compounds adopt three-dimensional frameworks. A distinct structural feature in the two structures is the presence of chains of Bi atoms with alternating short Bi-Bi bonds of around 3.1 Å and longer distances of around 4.6 Å. The optical band gaps of 1.42(2) eV for Bi3In4S10 and 1.45(2) eV for Bi14.7In11.3S38 were deduced from the diffuse reflectance spectra. 相似文献
88.
Anil C.A. Jayasundera Yang Li Philip Lightfoot 《Journal of solid state chemistry》2010,183(2):356-5993
The solvothermal syntheses and crystal structures of three indium fluorides are presented. K5In3F14 (1) and β-(NH4)3InF6 (2) are variants on known inorganic structure types chiolite and cryolite, respectively, with the latter exhibiting a complex and apparently novel structural distortion. [NH4]3[C6H21N4]2[In4F21] (3) represents a new hybrid composition displaying a unique trimeric metal fluoride building unit. 相似文献
89.
The local structure of In2O3 cosubstituted with Zn and Sn (In2−2xSnxZnxO3, x≤0.4 or ZITO) was determined by extended X-ray absorption fine structure (EXAFS) for x=0.1, 0.2, 0.3 and 0.4. The host bixbyite In2O3 structure is maintained up to the enhanced substitution limit (x=0.4). The EXAFS spectra are consistent with random substitution of In by the smaller Zn and Sn cations, a result that is consistent with the “good-to-excellent” conductivities reported for ZITO. 相似文献
90.
Siew Leng Lim Yiliang LiuJing Li En-Tang KangChong Kim Ong 《Applied Surface Science》2011,257(15):6612-6617
Transparent TiO2 nanotube arrays of micrometer lengths were prepared by anodization of titanium thin film RF sputtered on indium tin oxide (ITO) which was coated on glass substrate. The sputtering process took place at elevated temperature of 500 °C. The structures of the films were studied using scanning electron microscopy (SEM) and X-ray diffraction (XRD) while the optical properties of the films were investigated using UV-visible spectroscopy. Two types of electrolytes were used in this work: an aqueous mixture of acetic acid and HF solution and a mixture of NH4F and water dissolved in ethylene glycol. The concentration of NH4F, voltage and the thickness of the sputtered titanium film were varied to study their effect on the formation of TiO2 nanotube arrays. It is demonstrated in this work that the nanoporous layer is formed on top of the ordered array of TiO2 nanotubes. Furthermore, the optical transmittance of TiO2 nanotubes annealed at 450 °C is much lower than the non annealed TiO2 nanotubes in the visible wavelength region. 相似文献