全文获取类型
收费全文 | 332篇 |
免费 | 13篇 |
专业分类
化学 | 267篇 |
晶体学 | 2篇 |
力学 | 6篇 |
数学 | 19篇 |
物理学 | 51篇 |
出版年
2021年 | 5篇 |
2020年 | 10篇 |
2019年 | 4篇 |
2018年 | 3篇 |
2016年 | 8篇 |
2015年 | 6篇 |
2014年 | 14篇 |
2013年 | 16篇 |
2012年 | 20篇 |
2011年 | 21篇 |
2010年 | 15篇 |
2009年 | 16篇 |
2008年 | 22篇 |
2007年 | 19篇 |
2006年 | 19篇 |
2005年 | 14篇 |
2004年 | 12篇 |
2003年 | 9篇 |
2002年 | 17篇 |
2001年 | 3篇 |
2000年 | 4篇 |
1999年 | 2篇 |
1997年 | 5篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1981年 | 2篇 |
1979年 | 4篇 |
1977年 | 2篇 |
1933年 | 2篇 |
1921年 | 2篇 |
1913年 | 2篇 |
1911年 | 2篇 |
1906年 | 2篇 |
1905年 | 2篇 |
1904年 | 3篇 |
1902年 | 3篇 |
1901年 | 5篇 |
1897年 | 2篇 |
1892年 | 2篇 |
1884年 | 4篇 |
1883年 | 2篇 |
1882年 | 3篇 |
1880年 | 4篇 |
1878年 | 3篇 |
排序方式: 共有345条查询结果,搜索用时 31 毫秒
31.
A. Gautier E. Etard F. Coppola C. Willgerodt J. Guareschi A. Mosso Carl Arnold und C. Gaethgens 《Fresenius' Journal of Analytical Chemistry》1884,23(1):285-288
Ohne Zusammenfassung 相似文献
32.
33.
D. Pasquet J. L. Gautier P. Pouvil 《International Journal of Infrared and Millimeter Waves》1986,7(3):357-364
Very simple analytical expressions are proposed for the reflection coefficients of coupling holes used in FIR waveguide lasers. The relations are carried out for dielectric and metallic circular waveguides. 相似文献
34.
Eliminating the contribution of interfering compounds is a key step in chemical analysis. In complex media, one possible approach is to perform a preliminary separation. However purification is often demanding, long, and costly; it may also considerably alter the properties of interacting components of the mixture (e.g. in a living cell). Hence there is a strong interest for developing separation-free non-invasive analytical protocols. Using photoswitchable probes as labelling and titration contrast agents, we demonstrate that the association of a modulated monochromatic light excitation with a kinetic filtering of the overall observable is much more attractive than constant excitation to read-out the contribution from a target probe under adverse conditions. An extensive theoretical framework enabled us to optimize the out-of-phase concentration first-order response of a photoswitchable probe to modulated illumination by appropriately matching the average light intensity and the radial frequency of the light modulation to the probe dynamics. Thus, we can selectively and quantitatively extract from an overall signal the contribution from a target photoswitchable probe within a mixture of species, photoswitchable or not. This simple titration strategy is more specifically developed in the context of fluorescence imaging, which offers promising perspectives. 相似文献
35.
36.
37.
Different ternary alkaline-earth and rare-earth metal boron carbide and silicide compounds are examined using the solid-state language of Zintl-Klemm concept, band structures, and density of states, in order to show that the topology of the non-metal sub-lattice is highly dependent on the electron count. It is also shown that the chemistry of rare-earth metal-boron-silicon does not parallel that of rare-earth metal-boron-carbon. B-C bonds are easily formed in the latter, leading to a large variety of different structural arrangements, whereas Si-B bonds are hardly observed in the former, except in insertion compounds. 相似文献
38.
Adolfo Casali Schlagdenhauffen Arm Gautier L. Brieger E. Salkowski und H. Salkowski 《Fresenius' Journal of Analytical Chemistry》1883,22(1):638
Ohne Zusammenfassung 相似文献
39.
J.Pierre Moeglin Bemard Gautier René Joecklé Dominique Bolmont 《Optics and Lasers in Engineering》1997,28(5):317-330
A measurement of the electrical parameters degradation of Si photodiodes irradiated by laser visible light has been performed. The laser is a Q-switched Nd:YAG, frequency doubled, operated in single pulse mode of 4 ns duration. The applied fluence levels range up to 90 J/cm2. Two kinds of irradiation process were applied: either a part of the detector active area was irradiated in single pulse mode, or a scanning of the whole detector active area was performed with successive identical pulses. It has been shown that the fluence necessary to induce significant changes (local decrease of 35%) in responsivity is several times the surface melting threshold fluence (0.5 J/cm2). Conversely, the dark current is the most sensitive parameter, increasing by about four times for high irradiation. The in-depth dopant distribution is altered by high fluence irradiation in a way that cannot be explained by simple thermal modelling. 相似文献
40.
Ashbrook SE Le Pollès L Gautier R Pickard CJ Walton RI 《Physical chemistry chemical physics : PCCP》2006,8(29):3423-3431
The distorted perovskites NaTaO(3) and NaNbO(3) have been studied using (23)Na multiple-quantum (MQ) MAS NMR. NaTaO(3) was prepared by high temperature solid state synthesis and the NMR spectra are consistent with the expected room temperature structure of the material (space group Pbnm), with a single crystallographic sodium site. Two samples of NaNbO(3) were studied. The first, a commercially available sample which was annealed at 900 degrees C, showed two crystallographic sodium sites, as expected for the room temperature structure of the material (space group Pbcm). The second sample, prepared by a low temperature hydrothermal method, showed the presence of four sodium sites, two of which match the expected room temperature structure and the second pair, another polymorph of the material (space group P21ma). This is consistent with powder X-ray diffraction data which showed weak extra peaks which can be accounted for by the presence of this second polymorph. Density functional theory (DFT) calculations support our conclusions, and aid assignment of the NMR spectra. Finally, we discuss the measured NMR parameters in relation to other studies of sodium in high coordination sites in the solid state. 相似文献