全文获取类型
收费全文 | 141篇 |
免费 | 0篇 |
专业分类
化学 | 59篇 |
数学 | 1篇 |
物理学 | 81篇 |
出版年
2021年 | 1篇 |
2018年 | 1篇 |
2013年 | 2篇 |
2012年 | 5篇 |
2011年 | 11篇 |
2010年 | 2篇 |
2009年 | 1篇 |
2008年 | 9篇 |
2007年 | 11篇 |
2006年 | 8篇 |
2005年 | 5篇 |
2004年 | 5篇 |
2003年 | 1篇 |
2002年 | 3篇 |
2001年 | 2篇 |
1999年 | 3篇 |
1996年 | 1篇 |
1995年 | 5篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1990年 | 7篇 |
1989年 | 4篇 |
1988年 | 3篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 7篇 |
1981年 | 3篇 |
1980年 | 4篇 |
1979年 | 7篇 |
1978年 | 1篇 |
1977年 | 3篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 6篇 |
1973年 | 1篇 |
1968年 | 2篇 |
1967年 | 1篇 |
排序方式: 共有141条查询结果,搜索用时 15 毫秒
1.
The disturbance of sleep by traffic noise is a major problem area in noise pollution. Extensive laboratory tests using multichannel electroencephalograms (EEG) have been carried out by many workers to determine the general response of people when exposed to noise during sleep. An experimental technique for obtaining results in people's homes has been developed using a simplified one-channel EEG. The responses of six people in the age range 19-24 were measured. A significant correlation was found between sleep disturbance and traffic noise when the noise is expressed in EPNdB. In the home experiments the subjects appeared to be approximately 10 dB less sensitive to noises than laboratory subjects for similar noise exposure. There also appeared to be some adaptation to the noise exposure; however, only one subject was tested for a period of 20 days and was insufficient to give definite results on adaptation. 相似文献
2.
3.
4.
5.
The ν3 fundamental band (CO stretch) of HDCO at 1724 cm?1 has been studied using both conventional infrared absorption and CO laser Stark spectroscopy. In addition to the excited-state (v3 = 1) rotational constants, improved constants for the ground state of HDCO have been obtained by combining previous microwave data with some infrared combination differences. The following constants were determined:
Constant | Ground state | state | Units |
1724.267 | cm?1 | ||
198 119.75 | 198 210.4 | MHz | |
34 910.646 | 34 676.6 | MHz | |
29 561.488 | 29 331.3 | MHz | |
2.3302 | 2.3486 | D | |
0.195 | 0.190 | D |