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221.
Matsui A Umezawa K Shindo Y Fujii T Citterio D Oka K Suzuki K 《Chemical communications (Cambridge, England)》2011,47(37):10407-10409
We report a novel near-infrared fluorescent calcium probe (KFCA), which has good optical properties such as intense NIR fluorescence emission (670 nm, QY: 0.24), excellent ON/OFF ratio (120-fold), and good wavelength-compatibility with visible-light-emissive fluorophores (Fluo-4, DsRed2), and which is applicable for real-time dual-colour intracellular Ca(2+) imaging. 相似文献
222.
Tobisu M Yamakawa K Shimasaki T Chatani N 《Chemical communications (Cambridge, England)》2011,47(10):2946-2948
A nickel-catalyzed reductive deoxygenation of aryl alkyl ethers and aryl pivalates has been developed. Hydrosilanes serve as a mild reducing agent. The present protocol allows the use of a pivalate group as a robust and traceless steering group in arene functionalization reactions. 相似文献
223.
A new method for producing uniformly sized metal droplets is proposed. In this method, an intermittent electromagnetic pinch force is applied to a capillary jet of liquid metal to generate fluctuations of equal interval on the surface of the jet. As the fluctuations grow, the liquid metal jet breaks into small droplets whose size depends on the frequency of the intermittent electromagnetic pinch force. The breakup of the capillary jet is numerically simulated by performing multiphase fluid flow analysis with surface tracking (volume of fluid method) and electromagnetic force analysis. The simulation results agree well with the results of model experiments. The jet breaks up into uniformly sized droplets when the frequency of the intermittent force equals the frequency that corresponds to the natural disturbance wavelength of the capillary jet. 相似文献
224.
The oxidative bromination of arenes was induced by a vanadium catalyst in the presence of a bromide salt and a Brønsted acid or a Lewis acid under molecular oxygen, which provides an eco-friendly bromination method as compared with a conventional bromination one with bromine. This catalytic reaction could be applied to the bromination of alkenes and alkynes to give the corresponding vic-bromides. Use of aluminum halide as a Lewis acid in place of a Brønsted acid was demonstrated to provide a more practical protocol for the oxidative bromination. From ketones, α-bromination products were obtained. AlBr3 was found to serve as both a bromide source and a Lewis acid to induce the bromination smoothly. 51V NMR experiment showed that this catalytic bromination is likely to depend on the redox cycle of a vanadium catalyst under molecular oxygen. 相似文献
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Eiji Ihara Takafumi Ueda Kotaro Yokoyama Yuka Fujiwara Kenzo Inoue Tomomichi Itoh Hiroaki Shimomoto Hikaru Momose Mitsufumi Nodono 《Journal of polymer science. Part A, Polymer chemistry》2013,51(12):2716-2724
Radical copolymerization behavior of alkyl cyclobutenecarboxylate‐derivatives 4‐6 and related norbornene‐derived compounds 7–9 is described. A variety of alkyl cyclobutenecarboxylates fused with cycloaliphatic framework ( 4–6 ) were prepared by [2 + 2] cycloaddition of five, six, and eight‐membered cycloolefins with alkyl propiolates [alkyl = Me, 2‐hydroxyethyl, and 3‐γ‐butyrolactonyl (γ‐BL)]. The fused cyclobutenecarboxylates 4–6 were radically copolymerized with n‐butyl acrylate (nBA) to afford random copolymers, and terpolymerized with alkyl methacrylates with bulky ester groups [alkyl = γ‐BL and 3‐(3‐methyladamantyl)]. The cyclobutane‐containing bicyclic framework incorporated in the resulting polymer backbone contributes to raising Tg of resulting copolymers. Similar results were obtained when a mixture of related norbornene‐derived compounds were used as monomers with an apparently enhanced Tg‐raising effect in the copolymerization with nBA. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 2716–2724 相似文献
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Tobisu M Xu T Shimasaki T Chatani N 《Journal of the American Chemical Society》2011,133(48):19505-19511
Two protocols for the nickel-catalyzed cross-coupling of aryl fluorides with aryl boronic esters have been developed. The first employs metal fluoride cocatalysts, such as ZrF(4) and TiF(4), which enable Suzuki-Miyaura reactions of aryl fluorides bearing electron-withdrawing (ketones, esters, and CF(3)), aryl and alkenyl groups as well as those comprising fused aromatic rings, such as fluoronaphthalenes and fluoroquinolines. The second protocol employs aryl fluorides bearing ortho-directing groups, which facilitate the difficult C-F bond activation process via cyclometalation. N-heterocycles, such as pyridines, quinolines, pyrazoles, and oxazolines, can successfully promote cross-coupling with an array of organoboronic esters. A study into the substituent effects with respect to both coupling components has provided fundamental insights into the mechanism of the nickel-catalyzed cross-coupling of aryl fluorides. 相似文献