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231.
Sebastian Reitzenstein Petra Rsch Marion A. Strehle Dorothea Berg Malgorzata Baranska Hartwig Schulz Eicke Rudloff Jürgen Popp 《Journal of Raman spectroscopy : JRS》2007,38(3):301-308
The value of different vegetable oils can be correlated with the content of polyunsaturated fatty acids, especially omega‐3‐fatty acids such as linolenic acid, because of their contribution to healthy nutrition. One expression for the degree of unsaturation is the iodine value normally measured with gas chromatography. The use of Raman spectroscopy allows a rapid calculation of the iodine value and, in addition, only in a minimal sample volume. Therefore, this method can be used in single rapeseeds in order to predict the iodine value before harvesting. Additionally, the method can also be used for breeding investigations. Here, the lipid content and composition of a plant can be predicted by measuring the seedling without destruction. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
232.
Marion Wienecke 《Hyperfine Interactions》2000,129(1-4):401-422
Using radioactive isotopes of shallow dopants (Ag, As, Rb) as well as of native or isoelectronic elements (Se, Te, Cd, Sr)
which were incorporated as host atoms and then transmuted into relevant dopants (transmutation doping) we investigated doping
phenomena occurring in the wide band gap II–VI compounds CdTe, ZnTe, ZnSe and SrS by the classical methods of semiconductor
physics: Hall effect, C–V and photoluminescence measurements. Thus, we could assign unambiguously defect features in electrical
and photoluminescence measurements to extrinsic dopants by means of the half lives of radioactive decay. In As doped ZnSe
samples we observed two states: a metastable effective mass like state and a deep state. The occurrence of the latter state
is always linked with the high resistivity of As doped ZnSe crystals. The transmutation doping experiments reveal that the
so-called self-compensation typical for wide band gab II–VI compounds can be overcome when the thermal treatment for dopant
incorporation is time separated from its electrical activation, achieved using transmutation at room temperature. Under these
conditions we found an almost one-to-one doping efficiency relative to the implanted dose. Thus, these investigations are
a contribution to understanding compensation phenomena occurring due to interactions between dopants and native defects during
conventional doping treatments.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
233.
Robert Rllig Christoph Plikat Marion B. Ansorge‐Schumacher 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(37):13094-13097
Pickering emulsions (PEs) are particle‐stabilized multiphase systems with promising features for synthetic applications. Described here is a novel, simplified set‐up employing catalytically active whole cells for simultaneous emulsion stabilization and synthetic reaction. In the stereoselective carboligation of benzaldehyde to (R)‐benzoin catalyzed by a benzaldehyde lyase in E. coli, the set‐up yielded maximum substrate conversion within very short time, while economizing material demand and waste. Formation and activity of freshly produced PEs were enhanced when the catalytic whole cells were covered with hydrophobic silicone prior to PE formation. Benchmarked against other easy‐to‐handle whole‐cell biocatalysts in pure organic solvent, neat substrate, an aqueous emulsion in substrate, and a micro‐aquatic system, respectively, the cell‐stabilized PE outperformed all other systems by far. 相似文献
234.
Nadège Handké Thomas Trimaille Elsa Luciani Marion Rollet Thierry Delair Bernard Verrier Denis Bertin Didier Gigmes 《Journal of polymer science. Part A, Polymer chemistry》2011,49(6):1341-1350
Poly(N‐acryloxysuccinimide) (PNAS) and poly(N‐acryloxysuccinimide‐co‐N‐vinylpyrrolidone) (P(NAS‐co‐NVP)) of adjustable molecular weights and narrow polydispersities were prepared by nitroxide‐mediated polymerization (NMP) in N,N‐dimethylformamide in the presence of free SG1 (N‐tert‐butyl‐N‐1‐diethylphosphono‐(2,2‐dimethylpropyl) nitroxide), with MAMA‐SG1 (N‐(2‐methylpropyl)‐N‐(1‐diethylphosphono‐2,2‐dimethylpropyl)‐O‐(2‐carboxylprop‐2‐yl)hydroxylamine) alkoxyamine as initiator. The reactivity ratios of NAS and NVP were determined to be rNAS = 0.12 and rNVP = 0, indicating a strong alternating tendency for the P(NAS‐co‐NVP) copolymer. NAS/NVP copolymerization was then performed from a SG1‐functionalized poly(D ,L ‐lactide) (PLA‐SG1) macro‐alkoxyamine as initiator, leading to the corresponding PLA‐b‐P(NAS‐co‐NVP) block copolymer, with similar NAS and NVP reactivity ratios as mentioned above. The copolymer was used as a surface modifier for the PLA diafiltration and nanoprecipitation processes to achieve nanoparticles in the range of 450 and 150 nm, respectively. The presence of the functional/hydrophilic P(NAS‐co‐NVP) block, and particularly the N‐succinimidyl (NS) ester moieties at the particle surface, was evidenced by ethanolamine derivatization and zeta potential measurements. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 相似文献
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The (Z)-4-(phenylamino) pent-3-en-2-one (PAPO) was synthesised applying carbon-based solid acid and described by experimental techniques. Calculated results reveal that its keto-amine form is more stable than its enol-imine form. A relaxed potential energy surface scan has been accomplished based on the optimised geometry of NH tautomeric form to depict the potential energy barrier related to intramolecular proton transfer. The spectroscopic results and theoretical calculations demonstrate that the intramolecular hydrogen bonding strength of PAPO is stronger than that in 4-amino-3-penten-2-one)APO(. In addition, molecular electrostatic potential, total and partial density of stats (TDOS, PDOS) and non-linear optical properties of the compound were studied using same theoretical calculations. Our calculations show that the title molecule has the potential to be used as molecular switch. 相似文献
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240.
This article discusses the structure of the far-wake of a towed sphere in a saline stratification. We compare very low Froude number experiments to existing results at higher Froude numbers and investigate the vertical structure of the far-wake in terms of their vorticity and density fields. We show that the vertical propagation of vorticity is viscously dominated and propose a simple three-dimensional model for the quasi-equilibrium of the structure in terms of the density field. 相似文献