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1.
Hyperfine Interactions - Conversion electron Mössbauer spectroscopy measurements have been made on a diamond sample synthesized by chemical vapour deposition. The sample was implanted with 70... 相似文献
2.
D. Naidoo K. A?t-Ameur M. Brunel A. Forbes 《Applied physics. B, Lasers and optics》2012,106(3):683-690
In this paper we demonstrate experimentally the intra-cavity generation of a coherent superposition of Laguerre–Gaussian modes
of zero radial order but opposite azimuthal order. The superposition is created with a simple intra-cavity stop that creates
equal losses for the two azimuthal modes, and we show that by adjustment of the stop we can produce modes up to azimuthal
order 8. The fact that we have a coherent superposition rather than an incoherent superposition is verified by intensity measurements,
propagation measurements and a decomposition of the field by an inner product executed on a phase-only spatial light modulator.
Such fields have relevance in quantum information and optical trapping. 相似文献
3.
We describe the implementation of an adaptive umbrella sampling method, making use of the weighted histogram analysis method, for computing multidimensional potential of mean force for chemical reaction in solution. The approach is illustrated by investigating the effect of aqueous solution on the free energy surface for the proton transfer reaction of [H(3)N-H-NH(3)](+) using a combined quantum mechanical and molecular mechanical AM1/TIP3P potential. 相似文献
4.
Johnson MM Naidoo JM Fernandes MA Mmutlane EM van Otterlo WA de Koning CB 《The Journal of organic chemistry》2010,75(24):8701-8704
Reaction of (2,4,5-trimethoxyphenyl)(2-hydroxyphenyl)methanone with ceric ammonium nitrate furnished the xanthone, 2,3-dimethoxy-9H-xanthen-9-one. Under the same conditions the related (1,4-dimethoxynaphthalen-2-yl)(2-hydroxyphenyl)methanone resulted in the formation of 12a-methoxy-5H-benzo[c]xanthenes 5,7(12aH)-dione. Other examples of this novel transformation are also outlined. 相似文献
5.
Hyperfine Interactions - 相似文献
6.
Themba Dube Inderasan Naidoo 《Topology and its Applications》2011,158(16):2257-2259
We address and correct an oversight that we have identified in Lemma 3.2 of Dube and Naidoo (2010) [2] and provide counterexamples to the original assertions. 相似文献
7.
Eugene Olivier Trevor M. Letcher Paramespri Naidoo Deresh Ramjugernath 《The Journal of chemical thermodynamics》2011,43(6):829-833
Activity coefficients at infinite dilution were determined for 27 solutes: n-alkanes, alk-1-enes, alk-1-ynes, cycloalkanes, alkylbenzenes, alcohols, and ketones in the ionic liquid 1-butyl-3-methylimidazolium hexafluoroantimonate, [BMIM][SbF6], by gas–liquid chromatography at three different temperatures, T = (313.15, 323.15, and 333.15) K. The results are compared to published data on related compounds. The partial molar excess enthalpy values at infinite dilution were calculated from the experimental data over the same temperature range. Selectivities and capacities at infinite dilution were calculated for the hexane/benzene and methanol/benzene systems from experimental infinite dilution activity coefficients and compared to the literature values for related ionic liquids, as well as to data on industrial molecular solvents. 相似文献
8.
The primary mechanism for relieving tensile strain in alpha-linked polysaccharides (e.g., [alpha-d-Glc-(1-->4)alpha-d-Glc]n) is achieved by complex rotations of the glycosidic linkages. This is shown through computer simulations of atomic force microscopy stretching experiments in combination with free energy calculations of the unfolding pattern for amylose. The experimental force-extension curve is reproduced and analyzed to reveal that the chair-to-boat conversions play a smaller role than previously proposed. 相似文献
9.
A. Mokhles Gerami K. Johnston H. P. Gunnlaugsson K. Nomura R. Mantovan H. Masenda Y. A. Matveyev T. E. Mølholt M. Ncube S. Shayestehaminzadeh I. Unzueta H. P. Gislason P. B. Krastev G. Langouche D. Naidoo S. Ólafsson the ISOLDE collaboration 《Hyperfine Interactions》2016,237(1):75
Emission Mössbauer spectroscopy has been utilised to characterize dilute 57Fe impurities in In 2O3 following implantation of 57Mn (T 1/2 = 1.5 min.) at the ISOLDE facility at CERN. From stoichiometry considerations, one would expect Fe to adopt the valence state 3 + , substituting In 3+, however the spectra are dominated by spectral lines due to paramagnetic Fe2+. Using first principle calculations in the framework of density functional theory (DFT), the density of states of dilute Fe and the hyperfine parameters have been determined. The hybridization between the 3d-band of Fe and the 2p band of oxygen induces a spin-polarized hole on the O site close to the Fe site, which is found to be the cause of the Fe2+ state in In 2O3. Comparison of experimental data to calculated hyperfine parameters suggests that Fe predominantly enters the 8b site rather than the 24d site of the cation site in the Bixbyite structure of In 2O3. A gradual transition from an amorphous to a crystalline state is observed with increasing implantation/annealing temperature. 相似文献
10.
H. Masenda S. Geburt K. Bharuth-Ram D. Naidoo H. P. Gunnlaugsson K. Johnston R. Mantovan T. E. Mølholt M. Ncube S. Shayestehaminzadeh H. P. Gislason G. Langouche S. Ólafsson C. Ronning ISOLDE Collaboration 《Hyperfine Interactions》2016,237(1):40
Emission Mössbauer Spectroscopy following the implantation of radioactive precursor isotope 57Mn+ (T 1/2= 1.5 min) into ZnO single crystals at ISOLDE/CERN shows that a large fraction of 57Fe atoms produced in the 57Mn beta decay is created as paramagnetic Fe3+ with relatively long spin-lattice relaxation times. Here we report on ZnO pre-implanted with 56Fe to fluences of 2×1013, 5×10 13 and 8 × 1013 ions/cm2 in order to investigate the dependence of the paramagnetic relaxation rate of Fe3+ on fluence. The spectra are dominated by magnetic features displaying paramagnetic relaxation effects. The extracted spin-lattice relaxation rates show a slight increase with increasing ion fluence at corresponding temperatures and the area fraction of Fe3+ at room temperature reaches a maximum contribution of 80(3)% in the studied fluence range. 相似文献