全文获取类型
收费全文 | 94篇 |
免费 | 1篇 |
专业分类
化学 | 51篇 |
力学 | 1篇 |
数学 | 7篇 |
物理学 | 36篇 |
出版年
2020年 | 1篇 |
2018年 | 2篇 |
2017年 | 2篇 |
2016年 | 1篇 |
2013年 | 9篇 |
2012年 | 4篇 |
2011年 | 1篇 |
2010年 | 2篇 |
2009年 | 6篇 |
2008年 | 1篇 |
2007年 | 1篇 |
2006年 | 1篇 |
2005年 | 2篇 |
2004年 | 7篇 |
2003年 | 9篇 |
2002年 | 6篇 |
2001年 | 5篇 |
2000年 | 5篇 |
1999年 | 7篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1994年 | 6篇 |
1993年 | 4篇 |
1992年 | 1篇 |
1986年 | 1篇 |
1985年 | 4篇 |
1984年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有95条查询结果,搜索用时 15 毫秒
51.
52.
53.
D. Liu W. Perrie Z. Kuang P. J. Scully A. Baum S. Liang S. P. Edwardson E. Fearon G. Dearden K. G. Watkins 《Applied physics. B, Lasers and optics》2012,107(3):795-801
Parallel beam frequency doubling of 170 fs, NIR pulses is demonstrated by placing a thin beta barium borate (BBO) nonlinear crystal after a spatial light modulator. Computer-generated holograms applied to the spatial light modulator create 18 parallel diffracted beams at the fundamental wavelength λ=775 nm, then frequency doubled to λ=387 nm and focussed inside the poly(methyl methacrylate) (PMMA) substrate for refractive index structuring. This procedure, demonstrated for the first time in PMMA, requires careful attention to phase matching of multiple beams and opens up dynamic parallel processing at UV wavelengths where nematic liquid crystal devices are more sensitive to optical damage. By overlapping filamentary modifications, an efficient, stable volume phase grating with dimensions 5×5×2.0 mm3 and pitch Λ=15 μm was fabricated in 18 minutes and reached a first-order diffraction efficiency of 70 % at the Bragg angle. 相似文献
54.
N. G. Semaltianos S. Logothetidis W. Perrie S. Romani R. J. Potter M. Sharp P. French G. Dearden K. G. Watkins 《Applied Physics A: Materials Science & Processing》2009,94(3):641-647
Nanoparticles of the II–VI semiconductors CdTe, CdSe and ZnTe were synthesized by laser ablation (387 nm, 180 fs, 1 kHz, pulse
energy of 7 μJ (fluence of 2 J/cm2)) of the target materials in methanol, de-ionized water and acetone. The nanoparticles size distributions follow log-normal
functions with median diameters between about 6 and 11 nm for the several materials. The nanoparticles have the same crystalline
structure as that of the corresponding bulk material and under the present conditions of ablation are rich in the higher volatility
element of the two in the binary alloy and oxidized. Photoluminescence emission in the green-yellow (∼570 nm) was detected
from CdSe nanoparticles. 相似文献
55.
G. Ooms C. Poelma P. Poesio MJ.B.M. Pourquie J. Westerweel 《International Journal of Multiphase Flow》2008
In an earlier publication some of the authors presented a theoretical model for the calculation of the influence of particle inertia and gravity on the turbulence in a stationary particle-laden flow. In the present publication the model is extended for application to a decaying suspension. Also a comparison is given between predictions made with the model and experimental data (own data and data reported in the literature) on a decaying turbulent flow with particles in a water tunnel or in a wind tunnel. For most of the experiments a prediction with reasonable accuracy and an interpretation is possible by means of the model. 相似文献
56.
57.
58.
59.
Abstract— The photo-oxidation by O2 (1 Δg ) of individual lipid components in egg yolk lecithin is examined as a function of time. The rate of oxidation is correlated with the degree of unsaturation in the fatty-acid chains. 相似文献
60.
O'Brien P Childs AC Ensor GJ Hill CL Kirby JP Dearden MJ Oxenford SJ Rosser CM 《Organic letters》2003,5(26):4955-4957
The first systematic study of the cis and trans stereoselectivity in the m-CPBA epoxidation of N-protected cyclic allylic amines has been completed. Mono-N-protected systems gave epoxides with cis stereochemistry (amides are better cis directors than sulfonamides or carbamates) whereas di-N-protected systems gave trans-epoxides (TsNBoc protection gave complete trans stereoselectivity). [structure: see text] 相似文献