全文获取类型
收费全文 | 93篇 |
免费 | 3篇 |
国内免费 | 1篇 |
专业分类
化学 | 57篇 |
力学 | 1篇 |
物理学 | 39篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 2篇 |
2020年 | 1篇 |
2019年 | 2篇 |
2017年 | 4篇 |
2016年 | 4篇 |
2015年 | 2篇 |
2014年 | 1篇 |
2013年 | 6篇 |
2012年 | 8篇 |
2011年 | 7篇 |
2010年 | 5篇 |
2009年 | 1篇 |
2008年 | 1篇 |
2007年 | 3篇 |
2006年 | 1篇 |
2004年 | 2篇 |
2003年 | 1篇 |
2002年 | 1篇 |
2001年 | 2篇 |
2000年 | 4篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1996年 | 7篇 |
1995年 | 7篇 |
1994年 | 5篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 4篇 |
1981年 | 1篇 |
1980年 | 1篇 |
排序方式: 共有97条查询结果,搜索用时 31 毫秒
1.
Piryatinskiĭ Yu. P. Yaroshchuk O. V. Dolgov L. A. Bidna T. V. Enke D. 《Optics and Spectroscopy》2004,97(4):537-542
Optics and Spectroscopy - The fluorescence of the nematic liquid crystal n-butyl-n′-methoxyazoxybenzene (BMAOB) in the form of a layer and in porous glasses with pores of different diameter... 相似文献
2.
G. E. Yefchak G. A. Schultz J. Allison C. G. Enke J. F. Holland 《Journal of the American Society for Mass Spectrometry》1990,1(6):440-447
The pulsed ion sources used in conventional time-of-flight mass spectrometry (TOFMS) generally do not provide adequate resolving power across the mass range required for applications such as gas chromatography combined with mass spectrometry (GC/MS). Theoretical and experimental aspects of beam deflection techniques, which provide time encoding for TOFMS with continuous ions sources, are explored here. In this approach, ion source conditions do not affect resolving power, allowing for a greater variety of ionization modes to be used. Theoretical predictions for the resolving power attainable with beam deflection, which are satisfactory for GC/MS applications, agree well with experimentally determined values. The combination of GC-beam deflection-TOFMS with time-array detection is evaluated, and the capabilities of this system are compared to those of scanning mass spectrometers. 相似文献
3.
Elise A. Dennis Alexander W. Gundlach–Graham Christie G. Enke Steven J. Ray Anthony J. Carado Charles J. Barinaga David W. Koppenaal Gary M. Hieftje 《Journal of the American Society for Mass Spectrometry》2013,24(5):690-700
Resolution in time–of–flight mass spectrometry (TOFMS) is ordinarily limited by the initial energy and space distributions within an instrument’s acceleration region and by the length of the field–free flight zone. With gaseous ion sources, these distributions lead to systematic flight–time errors that cannot be simultaneously corrected with conventional static–field ion–focusing devices (i.e., an ion mirror). It is known that initial energy and space distributions produce non–linearly correlated errors in both ion velocity and exit time from the acceleration region. Here we reinvestigate an old acceleration technique, constant–momentum acceleration (CMA), to decouple the effects of initial energy and space distributions. In CMA, only initial ion energies (and not their positions) affect the velocity ions gain. Therefore, with CMA, the spatial distribution within the acceleration region can be manipulated without creating ion–velocity error. The velocity differences caused by a spread in initial ion energy can be corrected with an ion mirror. We discuss here the use of CMA and independent focusing of energy and space distributions for both distance–of–flight mass spectrometry (DOFMS) and TOFMS. Performance characteristics of our CMA–DOFMS and CMA–TOFMS instrument, fitted with a glow–discharge ionization source, are described. In CMA–DOFMS, resolving powers (FWHM) of greater than 1000 are achieved for atomic ions with a flight length of 285 mm. In CMA–TOFMS, only ions over a narrow range of m/z values can be energy–focused; however, the technique offers improved resolution for these focused ions, with resolving powers of greater than 2000 for a separation distance of 350 mm. 相似文献
4.
5.
6.
O. V. Yaroshchuk Yu. P. Piryatinskiĭ L. A. Dolgov T. V. Bidna D. Enke 《Optics and Spectroscopy》2006,100(3):394-399
The fluorescence spectra of the nematic liquid crystal n-pentyl-n′-cyanobiphenyl (5CB) in porous glasses with pores from 1 to 44 nm in diameter are investigated. A decrease in the pore diameter leads to suppression of some long-wavelength spectral components corresponding to H-type predimer and dimer pairs (the molecular sieve effect). The spectrum of 5CB in small pores (smaller than 4 nm in diameter) can be explained by the superposition of the monomer fluorescence and the fluorescence of J-type dimer pairs of 5CB molecules, as well as associates of 5CB molecules and surface groups on pore walls. Exposure of samples to UV light enhances the molecular interaction in associates, possibly, due to the formation of strong chemical bonds. 相似文献
7.
Several critical aspects of stress measurements in composite materials by thermographic stress analysis (TSA; also SPATE method) have been investigated. The emphasis is on the observed effects of thermal-expansion coefficients with positive and negative signs, thickness of surface coating, and absolute temperature increases in the material due to cyclic loading. Heat transfer and mean stress effects are also discussed. 相似文献
8.
Ma Guofu Li Jindan Sun Kanjun Peng Hui Feng Enke Lei Ziqiang 《Journal of Solid State Electrochemistry》2017,21(2):525-535
Journal of Solid State Electrochemistry - Nitrogen-doped porous activated carbons have been fabricated through a simple and efficient carbonization method at 700 °C with the waste... 相似文献
9.
10.