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Aryan Morita Felipe P. Perona Martinez Mayeul Chipaux Nicolas Jamot Simon R. Hemelaar Kiran J. van der Laan Romana Schirhagl 《Particle & Particle Systems Characterization》2019,36(8)
Fluorescent nanodiamonds (FNDs) can be used as nanoscale magnetic resonance sensors and stable optical labels. As a first step for using FNDs as nanosensors inside cells, they have to be ingested. Several techniques that improve particle uptake have been used. A simple approach based on commercially available liposomes is used to improve uptake. Uptake into colon cancer cells (HT‐29 cells) is demonstrated. Additionally, it is shown for the first time that one can facilitate diamond uptake into yeast cells by removing the cell wall and creating a so‐called spheroplast. Finally, the characteristics of FNDs coated with lipids and their behavior inside the cells are evaluated. 相似文献
983.
Kazunari Naka Hirofumi Sato Akihiro Morita Fumio Hirata Shigeki Kato 《Theoretical chemistry accounts》1999,102(1-6):165-169
The free-energy profile for the Menshutkin-type reaction NH3 + CH3Cl → NH3CH3
+ + Cl− in aqueous solution is studied using the RISM-SCF method. The effect of electron correlation on the free-energy profile is
estimated by the RISM-MP2 method at the HF optimized geometries along the reaction coordinate. Solvation was found to have
a large influence on the vibrational frequencies at the reactant, transition state and product; these vibrational frequencies
are utilized to calculate the zero-point energy correction of the free-energy profile. The computed barrier height and reaction
exothermicity are in reasonable agreement with those of experiment and previous calculations. The change of solvation structure
along the reaction path is represented by radial distribution functions between solute-solvent atomic sites. The mechanisms
of the reaction are discussed from the view points of solute electronic and solvation structures.
Received: 26 June 1998/Accepted: 28 August 1998 / Published online: 2 November 1998 相似文献
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The chemical forms of arsenic in some herbivorous or mainly herbivorous marine animals and, in some cases, the algae on which they feed were determined by HPLC-ICP MS. In most cases arsenobetaine was present in the animals as well as arsenosugars consumed directly from the algae. However in the case of copepods Gladioferens imparipes fed only on the diatom Chaetoceros concavicornis which had been grown in axenic culture, arseno-betaine was absent. Arsenobetaine was also absent from the muscle of the silver drummer Kyphosus sydneyanus, although trimethyl-arsine oxide was present. This is the first reported case of the absence of arsenobetaine in a marine teleost fish and may be related to its fermentative faculty for digesting the macroalgae that it consumes. © 1997 by John Wiley & Sons, Ltd. 相似文献
987.
Major water-soluble arsenic compounds accumulated in some zoo- and phyto-plankton were identified. Zooplankton were collected at sampling stations in the Sea of Japan by a Norpac net towed from 600 m depth to the surface. Phytoplankton were cultivated under axenic conditions. Water-soluble arsenic compounds were extracted repeatedly from plankton tissues by aqueous methanol. The arsenic compounds in the extracts were analyzed by HPLC–ICP/MS. Among zooplankton analyzed in the present study, two carnivorous species, i.e. Amphipoda ( Themisto sp.) and Sagittoidea ( Sagitta sp.), contained arsenobetaine as the dominant arsenic species. Arsenobetaine was the major species in Euphausiacea ( Euphausia sp.), also. The most abundant arsenic compound in the herbivorous Copepoda species ( Calanus sp.), on the other hand, was an arsenic-containing ribofuranoside with a sulfate ester group, and arsenobetaine was only a minor component. Phytoplankton contained arsenic-containing ribofuranosides apparently in a species-speific manner. The arsenic compounds in zooplankton seem to reflect their feeding habit; i.e. carnivorous species eating zooplankton or other small animals accumulate arsenobetaine, while herbivorous ones eating phytoplankton accumulate arsenic-containing ribofuranosides as major arsenic compounds. 相似文献
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Selenium is an essential component of glutathione peroxidase and other enzyme systems and is therefore essential for animal metabolism. It is, however, toxic at concentrations little above those required for health. Some plants accumulate selenium from seleniferous soils and constitute a toxic hazard to grazing stock. The more complex organic selenium compounds that occur naturally in plants, animals and microorganisms have been characterized following their isolation or partial isolation, and have often been identified by their similarity to analogous sulphur compounds. The occurrence and identification of selenium compounds in biological samples and methods for their analysis are reviewed. Copyright © 2000 John Wiley & Sons, Ltd. 相似文献
990.