全文获取类型
收费全文 | 342篇 |
免费 | 4篇 |
国内免费 | 1篇 |
专业分类
化学 | 175篇 |
晶体学 | 7篇 |
力学 | 13篇 |
数学 | 47篇 |
物理学 | 105篇 |
出版年
2020年 | 2篇 |
2019年 | 3篇 |
2018年 | 2篇 |
2016年 | 5篇 |
2015年 | 5篇 |
2014年 | 8篇 |
2013年 | 28篇 |
2012年 | 12篇 |
2011年 | 12篇 |
2010年 | 12篇 |
2009年 | 9篇 |
2008年 | 20篇 |
2007年 | 13篇 |
2006年 | 15篇 |
2005年 | 16篇 |
2004年 | 15篇 |
2003年 | 17篇 |
2002年 | 7篇 |
2001年 | 3篇 |
2000年 | 5篇 |
1999年 | 9篇 |
1998年 | 6篇 |
1997年 | 3篇 |
1996年 | 6篇 |
1993年 | 4篇 |
1992年 | 4篇 |
1990年 | 5篇 |
1989年 | 5篇 |
1988年 | 4篇 |
1987年 | 5篇 |
1986年 | 6篇 |
1985年 | 6篇 |
1984年 | 6篇 |
1983年 | 5篇 |
1981年 | 8篇 |
1980年 | 7篇 |
1979年 | 4篇 |
1978年 | 3篇 |
1977年 | 4篇 |
1976年 | 3篇 |
1975年 | 3篇 |
1974年 | 2篇 |
1973年 | 5篇 |
1972年 | 3篇 |
1971年 | 2篇 |
1968年 | 4篇 |
1967年 | 2篇 |
1966年 | 3篇 |
1963年 | 1篇 |
1937年 | 2篇 |
排序方式: 共有347条查询结果,搜索用时 171 毫秒
31.
Johansen LM 《Physical review letters》2004,93(12):120402
The exact conditions on valid probe states for weak measurements are derived. It is demonstrated that weak measurements can be performed with any probe state with vanishing probability current density. This condition is found both for weak measurements of noncommuting observables and for c-number observables. In addition, the interaction between object and probe must be sufficiently weak. Strange weak values can be observed also with mixed probe states, but not for c-number observables. 相似文献
32.
Halland N Hansen T Jørgensen KA 《Angewandte Chemie (International ed. in English)》2003,42(40):4955-4957
33.
34.
I. Lange G. F. Nadeau L. E. Branchen D. G. Kerr A. E. Hill W. M. Malisoff S. I. Schodzew und E. M. Johansen 《Fresenius' Journal of Analytical Chemistry》1937,109(1-2):55-59
Ohne Zusammenfassung 相似文献
35.
36.
The full (1)H and (13)C NMR chemical shift assignment of 2α-methyl-17α(H),21β(H)-hopane is presented. This compound is formed in mature sediments from biogenic sources of 2β-methyl-17β(H),21β(H)-hopanoids, which include several cyanobacteria. In addition, full (1)H and (13)C NMR chemical shift data of all four 17,21 isomers of 3β-methylhopane have been assigned. The thermodynamically most stable 3β-configuration corresponds to that found in bacterial sources. The data presented here suggest minor corrections to the (13)C chemical assignments reported earlier for 17α(H)-hopanes. Moreover, spectral evidence indicates an unexpected ring-D boat conformation of 17α(H),21α(H)-hopanes, which may serve to explain the steric strain reported for this isomer. 相似文献
37.
H. Roy-Poulsen E. Johnson A. Johansen L. Sarholt-Kristensen H. Hayashi 《Hyperfine Interactions》1986,29(1-4):1201-1204
Martensitic transformations have been analysed in a series of antimony implanted austenitic stainless steels using CEMS. The
implanted samples contain about 70 vols martensite, which is considerably more than can be formed conventionally by plastic
deformation or cooling below the martensite start temperature. CEM spectra from implantation induced martensite and from martensite
formed in conventional processes are virtually identical. In both cases the hyperfine field is ≈ 25T. 相似文献
38.
Analytical and numerical study on grating depth effects in grating coupled waveguide sensors 总被引:1,自引:0,他引:1
R. Horvath L. C. Wilcox H. C. Pedersen N. Skivesen J. S. Hesthaven P. M. Johansen 《Applied physics. B, Lasers and optics》2005,81(1):65-73
The in-coupling process for grating-coupled planar optical waveguide sensors is investigated in the case of TE waves. A simple analytical model based on the Rayleigh–Fourier–Kiselev method is applied to take into account the depth of the grating coupler, which is usually neglected in the modeling. Analytical expressions are derived both for the position and width of the in-coupling peaks to illustrate the effects of grating depth on the guided mode resonances in grating coupled waveguide sensors. Numerical computations verify the model for shallow gratings both in terms of peak shape and position and provide the limitations for the analytical formulas. 相似文献
39.
40.
A high-performance size-exclusion chromatographic procedure, using Nucleosil Diol, for the quantitative analysis of fluoresceinyl isothiocyanate dextrans of various molecular masses (10,000-150,000) in biological media was developed. The influence of the molecular mass and the degree of substitution of the conjugates on the chromatographic behaviour are discussed. In addition to quantitation, the molecular mass of the conjugates with degree of substitution below 1.6 could be estimated from the chromatograms. Linear standard calibration curves were obtained at concentrations down to 0.050 micrograms ml-1 in rabbit plasma and urine and homogenates of rabbit liver, lymph node and muscle when the derivative (degree of substitution 0.85) was monitored by fluorescence detection (lambda ex = 493 nm, lambda em = 520 mm). The fluoresceinyl isothiocyanate dextrans were found to be stable for more than three days at 37 degrees in all biological media under investigation. A pH-rate profile for the alkaline hydrolysis of fluoresceinyl isothiocyanate dextrans was constructed. The applicability of the method to pharmacokinetic studies was demonstrated by recording the plasma concentration-time profile of a fluoresceinyl isothiocyanate dextran T-70 conjugate following intravenous injection to a rabbit. In relation to future pharmacokinetic investigations on dextran conjugates, the results reported indicate that labelling of the parent dextran with fluoresceinyl isothiocyanate and monitoring of the fluoresceinyl isothiocyanate dextran conjugate throughout the organism using the described method is a promising development. 相似文献