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351.
We address M-ary communication channels based on entangled two-mode states of radiation in the presence of losses. In particular we focus
on channels build by two-mode coherently-correlated (TMC) or twin-beam (TWB) states. Optimized bit discrimination thresholds,
as well as the corresponding maximized mutual information, are explicitly evaluated as a function of beam intensities and
loss parameters for binary and quaternary alphabets. The evolution of the two entangled support states in lossy channels is
analyzed and the joint photon number distribution is evaluated, showing that the beam statistics (either sub-Poissonian for
TMC or super-Poissonian for TWB) is not altered by channel losses. The effects of losses on the channel security is discussed.
The text was submitted by the authors in English. 相似文献
352.
Boyard-Kieken F Dervilly-Pinel G Garcia P Paris AC Popot MA le Bizec B Bonnaire Y 《Journal of separation science》2011,34(24):3493-3501
Growth hormone (GH) is a polypeptide suspected of being used in horse racing to speed up physical performances. Despite scientific advances in the recent years, the control of its administration remains difficult. In order to improve it, a metabolomics study through LC-high resolution mass spectrometry measurements was recently initiated to assess the metabolic perturbations caused by recombinant equine growth hormone administration. Few tens of ions not identified structurally were highlighted as compounds responsible for the modification of metabolic profiling observed in treated animals. This previous work was based on the use of Uptisphere Strategy NEC as the chromatographic column. In parallel, more and more metabolomics studies showed the interest of the use of new chromatographic supports such as hydrophilic interaction chromatography for the analysis of polar compounds. It is in this context that an investigation was conducted on Uptisphere HDO and Luna hydrophilic interaction chromatography stationary phases to generate and process urinary metabolomics fingerprints, which could allow to establish a comparison with Uptisphere Strategy NEC. The chromatographic column the most adapted for the detection of new biomarkers of GH administration has been used to set up a relevant statistical model based on the analysis of more than hundred biological samples. 相似文献
353.
Abstract
Parkinson’s disease is characterized by the selective degeneration of neuromelanin-containing dopaminergic neurons in the substantia nigra and locus coeruleus. Although the cause of this disease remains unknown, several transition metals, including manganese and copper, have been associated with the development of the atypical form of Parkinsonism, and iron accumulation has been associated with the development of Parkinson’s disease. Manganese3+ is a strong oxidizing agent, which oxidizes dopamine to aminochrome (dopaminochrome), the precursor of neuromelanin. Aminochrome formation in cell culture medium induces acute cell death in cells that uptake aminochrome, explaining the role of manganese in the development of atypical Parkinsonism. Copper accumulation in Wilson’s disease also induces Parkinsonism as one of the main symptoms, and an atypical Parkinsonism has also been observed in young copper miners. Interestingly, copper is able to complex with dopamine, which can be taken up by cells expressing the dopamine transporter, inducing caspase-independent cell death with formation of autophagic vacuoles. Iron is also able to form a complex with dopamine, the neurotoxic action of which also depends on the cellular expression of the dopamine transporter. The neurotoxicities of these transition metals to cells expressing the dopamine transporter all involve dopamine oxidation to quinones and require the inhibition of DT-diaphorase. 相似文献354.
Galan JA Paris LL Zhang HJ Adler J Geahlen RL Tao WA 《Journal of the American Society for Mass Spectrometry》2011,22(2):319-328
Green fluorescent protein (GFP) and variants have become powerful tools to study protein localization, interactions, and dynamics.
We present here a mass spectrometry-based proteomics strategy to examine protein–protein interactions using anti-GFP single-chain
antibody VHH in a combination with a novel stable isotopic labeling reagent, isotope tag on amino groups (iTAG). We demonstrate that
the single-chain VHH (GFP nanotrap) allows us to identify interacting partners of the Syk protein-tyrosine kinase bearing a GFP epitope tag with
high efficiency and high specificity. Interacting proteins identified include CrkL, BLNK, α- and β-tubulin, Csk, RanBP5 and
DJ-1. The iTAG reagents were prepared with simple procedures and characterized with high accuracy in the determination of
peptides in model peptide mixtures and as well as in complex mixture. Applications of the iTAG method and GFP nanotrap to
an analysis of the nucleocytoplasmic trafficking of Syk led to the identification of location-specific associations between
Syk and multiple proteins. While the results reveal that the new quantitative proteomic strategy is generally applicable to
integrate protein interaction data with subcellular localization, extra caution should be taken in evaluating the results
obtained by such affinity purification strategies as many interactions appear to occur following cell lysis. 相似文献
355.
By means of in situ small-angle x-ray diffraction experiments and semi-grand-canonical ensemble Monte Carlo simulations we demonstrate that sorption and condensation of a fluid confined within nanopores is capable of deforming the pore walls. At low pressures the pore is widened due to a repulsive interaction caused by collisions of the fluid molecules with the walls. At capillary condensation the pores contract abruptly on account of attractive fluid-wall interactions whereas for larger pressures they expand again. These features cannot solely be accounted for by effects related to pore-wall curvature but have to be attributed to fluid-wall dispersion forces instead. 相似文献
356.