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171.
Martin Hoefling Francesco Iori Dr. Stefano Corni Dr. Kay‐Eberhard Gottschalk Dr. 《Chemphyschem》2010,11(8):1763-1767
The interactions of amino acids with inorganic surfaces are of interest for biologists and biotechnologists alike. However, the structural determinants of peptide–surface interactions have remained elusive, but are important for a structural understanding of the interactions of biomolecules with gold surfaces. Molecular dynamics simulations are a tool to analyze structures of amino acids on surfaces. However, such an approach is challenging due to lacking parameterization for many surfaces and the polarizability of metal surfaces. Herein, we report DFT calculations of amino acid fragments in vacuo and molecular dynamics simulations of the interaction of all amino acids with a gold(111) surface in explicit solvent, using the recently introduced polarizable gold force field GolP. We describe preferred orientations of the amino acids on the metal surface. We find that all amino acids preferably interact with the gold surface at least partially with their backbone, underlining an unfolding propensity of gold surfaces. 相似文献
172.
Thuro Arnold Kay Großmann Nils Baumann 《Analytical and bioanalytical chemistry》2010,396(5):1641-1653
Biofilms may immobilize toxic heavy metals in the environment and thereby influence their migration behaviour. The mechanisms
of these processes are currently not understood, because the complexity of such biofilms creates many discrete geochemical
microenvironments which may differ from the surrounding bulk solution in their bacterial diversity, their prevailing geochemical
properties, e.g. pH and dissolved oxygen concentration, the presence of organic molecules, e.g. metabolites, and many more,
all of which may affect metal speciation. To obtain such information, which is necessary for performance assessment studies
or the development of new cost-effective strategies for cleaning waste waters, it is very important to develop new non-invasive
methods applicable to study the interactions of metals within biofilm systems. Laser fluorescence techniques have some superior
features, above all very high sensitivity for fluorescent heavy metals. An approach combining confocal laser scanning microscopy
and laser-induced fluorescence spectroscopy for study of the interactions of biofilms with uranium is presented. It was found
that coupling these techniques furnishes a promising tool for in-situ non-invasive study of fluorescent heavy metals within
biofilm systems. Information on uranium speciation and uranium redox states can be obtained. 相似文献
173.
We identify conditions under which correlations resulting from quantum measurements performed on macroscopic systems (systems composed of a number of particles of the order of the Avogadro number) can be described by local realism. We argue that the emergence of local realism at the macroscopic level is caused by an interplay between the monogamous nature of quantum correlations and the fact that macroscopic measurements do not reveal properties of individual particles. 相似文献
174.
Jewart CM Chen T Lindner E Fiebrandt J Rothhardt M Schuster K Kobelke J Bartelt H Chen KP 《Optics letters》2011,36(23):4491-4493
This Letter presents simulation and experimental results that explore bending insensitivity of fiber Bragg gratings in suspended-core optical fibers. The implementation of thin silica bridge in the fibers enhances index contrast of the fiber core and reduces bending-induced strain transfer to the fiber core. This fiber design lead to a reduction of over 7 times in strain-induced fiber Bragg grating resonant peak shifts in the suspended-core fiber compared with that in standard telecommunication fiber, and an 0.14 dB bending loss at a bending radius of 6.35 mm. 相似文献
175.
176.
The control of regiochemistry in the synthesis of polysaccharide derivatives is one of the most significant scientific challenges
in the field. Its importance is only further highlighted by the individual successes in synthesis of regioselectively substituted
derivatives, in particular cellulose esters and ethers, over the last 20 years. The availability of these samples and studies
of their properties versus randomly substituted analogs has shown clearly that properties like solubility, aggregation phenomena,
and optical properties depend heavily on the regiochemistry of substitution. We report here on the one-pot synthesis of novel
6-bromo-6-deoxy-2,3-O-acylcellulose derivatives, which as more organic soluble derivatives of 6-bromo-6-deoxycellulose should allow broader exploitation
of the highly regioselective cellulose 6-bromination chemistry. We illustrate the potential of these new derivatives by conversion
to 6-cyano-6-deoxycellulose esters. 相似文献
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179.
Blends of a tetrafunctional epoxy resin, tetraglycidyl‐4,4′‐diaminodiphenylmethane (TGDDM), and a hydroxyl‐functionalized hyperbranched polymer (HBP), aliphatic hyperbranched polyester Boltorn H40, were prepared using 3,3′‐diaminodiphenyl sulfone (DDS) as curing agent. The phase behavior and morphology of the DDS‐cured epoxy/HBP blends with HBP content up to 30 phr were investigated by differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and scanning electron microscopy (SEM). The phase behavior and morphology of the DDS‐cured epoxy/HBP blends were observed to be dependent on the blend composition. Blends with HBP content from 10 to 30 phr, show a particulate morphology where discrete HBP‐rich particles are dispersed in the continuous cured epoxy‐rich matrix. The cured blends with 15 and 20 phr exhibit a bimodal particle size distribution whereas the cured blend with 30 phr HBP demonstrates a monomodal particle size distribution. Mechanical measurements show that at a concentration range of 0–30 phr addition, the HBP is able to almost double the fracture toughness of the unmodified TGDDM epoxy resin. FTIR displays the formation of hydrogen bonding between the epoxy network and the HBP modifier. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 417–424, 2010 相似文献
180.
Kay Gore 《School science and mathematics》1986,86(3):263-265
Computer Science II: File Structure Charged Particles II South Dakota: An Economic and Math Simulation 相似文献