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11.
K.P. Jain S. Nakashima M. Jouanne E. Amzallag M. Balkanski 《Solid State Communications》1980,33(10):1079-1082
Raman scattering has been measured at low temperatures on Li doped ZnTe, using Kr and dye lasers. Besides the usual phonon spectrum, electronic transitions between acceptor bound states 1S→2S (A band), 1S→3S, 1S→4S, are observed. A peak located between the TO and LO bands is interpreted in terms of a bound LO-phonon mode related to the p acceptor states. The sidebands of the A band, at one and two LO-phonons are observed as well, whose energies are found to be respectively 12 and 26 cm?1 smaller than the expected values. A simple self-energy model is invoked to explain the energy shift due to electron-phonon interaction. 相似文献
12.
Contribution of lattice defects and shallow impurities to electron-hole droplet (EHD) formation has been confirmed by the study on photoluminescence due to EHD's in various kinds of silicon crystals. Sample dependence of the EHD luminescence peak energy shift in the variation of the excitation intensity is explained in terms of the surface energy contribution to EHD binding energy and concentrations of EHD's and impurities. 相似文献
13.
Lifetime of the first excited state of donor-acceptor pairs has been measured in ZnTe as a function of the donor-acceptor distance. The measured lifetime for the radiative recombinations of donor-acceptor pairs agrees well with the calculated one in which the central cell correction for the 1s state of the acceptors is taken into account. It has been found that the lifetime depends on the impurity concentration. The concentration dependence is discussed in connection with the non-exponential decay of the luminescence observed for more distant donor-acceptor pairs. 相似文献
14.
Satoru Nakashima Yuichi Masuda Izumi Motoyama Hirotoshi Sano 《Hyperfine Interactions》1988,40(1-4):319-322
It was found that the packing of cations and anions influences the electronic structures of mixed-valence binuclear ferrocene derivatives. Temperature-dependence of the mixed-valence state of 11, 1111-diisobutylbiferrocenium triiodide was observed in a crystalline state, whereas only a trapped-valence state was found in a dispersed state. The packing effect was also observed for a series of 11, 1111-dialkyl- and 11, 1111-bis(methylbenzyl)biferrocenium triiodides by means of ESR spectroscopy. 相似文献
15.
Fe(NCS)2(bpa)2, Co(NCS)2(bpa)2, and Fe0.5Co0.5(NCS)2(bpa)2 were synthesized. X-ray structural analysis revealed that the structure was the same among the three complexes. Although the metal-ligand distance in the mixed crystals was shorter than the distance in Fe(NCS)2(bpa)2 and was similar to that in Co(NCS)2(bpa)2, the spin state remained temperature-independent FeII high-spin state in 57Fe M?ssbauer spectra. 相似文献
16.
Satoru Nakashima Masashi Kaneko Keisuke Yoshinami Saki Iwai Haruka Dote 《Hyperfine Interactions》2018,239(1):39
The present study reveals the on/off of spin-crossover (SCO) phenomenon in assembled Fe(II) complexes bridged by bis(pyridyl) type ligand. Whether SCO phenomenon occurs or not in assembled Fe(II) complexes bridged by bis(pyridyl) type ligand is determined by local structure around iron atom. SCO phenomenon occurs when the coordinating pyridines facing to each other across the iron atom are propeller type, while the phenomenon does not occur when they are parallel type or distorted propeller type. DFT calculation explained that, in the shortening of Fe-pyridine bonds when changing from high-spin state to low-spin state, the pyridines of propeller type can approach the iron atom with smaller steric hindrance than those of parallel and distorted propeller type complexes. The local structure is controlled by introducing methyl substituent and introducing π-system, changing SCO phenomenon. And the transition temperature of SCO is also controlled in assembled complexes bridged by 1,2-bis(4-pyridyl)ethane by mixing anionic ligand. 相似文献
17.
We report an experimental study of time characteristics of secondary emission in CdxZn1-xTe mixed crystals (x = 0.32) under resonant excitation with a picosecond dye laser. When the incident laser frequency is tuned on to the luminescence maximum of localized excitons, the decay curve of the intensity of “Raman-like” lines exhibits a single exponential decay. Off resonance, however, a short-lived component corresponding to Raman scattering appears in addition to the long-lived component. The intensity of the Raman component relative to that of the luminescence component increases with increase of the off-resonance frequency. From these temporal behaviors, we have found, for the first time, the transformation of resonant Raman scattering into luminescence in mixed crystals as a function of incident frequencies. 相似文献
18.
K. Yatsu T. Cho H. Higaki M. Ichimura K. Ishii Y. Ishimoto M. K. Islam A. Itakura I. Katanuma J. Kohagura Y. Nakashima T. Saito Y. Takemura Y. Tatematsu M. Yoshida M. Yoshikawa 《Czechoslovak Journal of Physics》2002,52(10):1143-1148
GAMMA 10 experiments have advanced in high density experiments after the last EPS Workshop where we reported high density
plasma production by using an ion cyclotron range of frequency heating at a high harmonic frequency and neutral beam injection
in the central cell. Recently a high density plasma was obtained with much improved reproducibility than before and without
degradation of diamagnetic signal. The high density plasma was attained by adjusting the spacing of the conducting plates
installed in the anchor transition regions. Dependencies of particle confinement time, ion energy confinement time and plasma
confining potential on plasma density were obtained for the first time in the high density region.
Presented at 5th Workshop “Role of Electric Fields in Plasma Confinement and Exhaust”, Montreus, Switzerland, June 23–24,
2002. 相似文献
19.
In 1′, 1‴-dibutylbiferrocenium triiodide crystals A show temperature-independent trapped-valence state, while crystals B show
a valence-delocalization of the mixed-valence state. The mixed-valence states of both crystals are discussed in relation to
their crystal structures.
Address after October 1991: Department of Chemistry, Faculty of Science, Hiroshima University, Kagamiyama, Higashi-Hiroshima
724, Japan 相似文献
20.