全文获取类型
收费全文 | 72篇 |
免费 | 0篇 |
专业分类
化学 | 11篇 |
数学 | 1篇 |
物理学 | 60篇 |
出版年
2023年 | 1篇 |
2019年 | 1篇 |
2015年 | 1篇 |
2014年 | 2篇 |
2013年 | 1篇 |
2012年 | 1篇 |
2009年 | 1篇 |
2008年 | 3篇 |
2007年 | 1篇 |
2006年 | 2篇 |
2005年 | 2篇 |
2001年 | 4篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1994年 | 6篇 |
1993年 | 6篇 |
1992年 | 8篇 |
1991年 | 6篇 |
1989年 | 3篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1982年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有72条查询结果,搜索用时 286 毫秒
41.
Michael A. Stroscio 《Optics Communications》1977,21(2):267-271
It is shown that the detection of 511 keV photons provides a simple and direct method for relating the total number of suprathermal electrons in a laser-heated plasma to the temperature of the suprathermal electrons. Furthermore, it is shown that this method clearly differentiates between the thermal and suprathermal electron populations in contrast to X-ray methods. An explicit relationship between the number of suprathermal electrons, the suprathermal temperature, and the number of 511 keV photons is derived. 相似文献
42.
The chemisorption, condensation, desorption, and decomposition of methanol, both CH3OH and CH3OD, on a clean Ni(110) surface have been characterized using high resolution electron energy loss spectroscopy, temperature programmed reaction spectroscopy, and low energy electron diffraction. The vibrational spectrum of the saturated chemisorbed layer, 7.4 × 1014 molecules cm?2, is almost identical to the infrared spectrum of liquid or solid methanol. Condensation of multilayers of methanol is facile at 80 K. The only quasi-stable intermediate isolated during the decomposition is a methoxy species, CH3O, which decomposes thermally to CO and H. The evolution of both CO and H2 occurs in desorption limited processes. 相似文献
43.
44.
45.
46.
47.
48.
49.
50.
Dussault PH Lee IQ Lee HJ Lee RJ Niu QJ Schultz JA Zope UR 《The Journal of organic chemistry》2000,65(25):8407-8414
The Lewis acid-mediated reaction of alkene nucleophiles with peroxyacetals provides an effective route for the synthesis of homologated peroxides and hydroperoxides. In the presence of Lewis acids such as TiCl(4), SnCl(4), and trimethylsilyl triflate, peroxyacetals and peroxyketals undergo reaction with allyltrimethylsilane, silyl enol ethers, and silyl ketene acetals to afford homoallyl peroxides, 3-peroxyketones, and 3-peroxyalkanoates, respectively. Reactions of peroxyacetals are Lewis acid dependent; TiCl(4) promotes formation of ethers while SnCl(4) and trimethylsilyl triflate promote formation of peroxides. Lewis acid-promoted reactions of silylated hydroperoxyacetals furnish silylated hydroperoxides, which can be deprotected to homologated hydroperoxides. Hydroperoxyketals undergo Lewis acid-mediated allylation to furnish 1,2-dioxolanes via attack of hydroperoxide on the intermediate carbocation. Lewis acid-mediated cyclization of unsaturated peroxyacetals furnishes 1,2-dioxanes, 1,2-dioxepanes, and 1,2-dioxacanes through 6-endo/exo, 7-endo/endo, and 8-endo/endo pathways. The corresponding reactions involving 6-endo/endo and 5-endo/exo pathways were unsuccessful. 相似文献