全文获取类型
收费全文 | 173篇 |
免费 | 3篇 |
专业分类
化学 | 11篇 |
晶体学 | 2篇 |
力学 | 1篇 |
数学 | 1篇 |
物理学 | 161篇 |
出版年
2022年 | 1篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2016年 | 1篇 |
2015年 | 1篇 |
2014年 | 8篇 |
2013年 | 5篇 |
2012年 | 5篇 |
2011年 | 20篇 |
2010年 | 18篇 |
2009年 | 8篇 |
2008年 | 16篇 |
2007年 | 12篇 |
2006年 | 13篇 |
2005年 | 6篇 |
2004年 | 7篇 |
2003年 | 9篇 |
2002年 | 7篇 |
2001年 | 12篇 |
2000年 | 6篇 |
1999年 | 4篇 |
1998年 | 6篇 |
1997年 | 3篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1992年 | 1篇 |
排序方式: 共有176条查询结果,搜索用时 15 毫秒
171.
172.
173.
Youwen Liu Liren Liu De'an Liu Liangying Xu Changhe Zhou 《Optics Communications》2001,190(1-6):339-343
Nonvolatile photorefractive gratings have been recorded in LiNbO3:Cu:Ce crystals by using a He–Ne laser (633 nm) for recording and an argon ion laser (458 nm) for sensitizing. The sensitizing light increases the recording sensitivity by a−bexp(−Is/c) and saturation behavior will appear with high enough intensity of sensitizing light. The recording light increases the slope of η1/2 as a function of time during the initial stages of hologram formation by sublinear Ixr (x<1) and thus the recording light decreases the recording sensitivity. The dependence of saturation diffraction efficiency on the intensities of the recording and sensitizing light shows that there is a maximum dynamic range of the recording process. 相似文献
174.
We present and characterize theoretically and experimentally a photorefractive velocimeter. This device, based on two-wave mixing in a rapid photorefractive crystal, measures the instantaneous velocity of a vibrating target. It is particularly adapted to the measurement of high-amplitude (as high as some mm) low-frequency (until some kHz) vibrations. Instantaneous velocity as high as 25 mm s−1 are expected to be measured with common photorefractive semiconductors and CW lasers. 相似文献
175.
Self-bending of photorefractive solitons 总被引:7,自引:0,他引:7
Self-bending of photorefractive solitons is caused by diffusion in photorefractive crystals and becomes an important effect when the beam size is in the range of the charge carriers diffusion length. In this paper we present an experimental and numerical examination of the beam bending dependence on relevant parameters such as the applied electric field and the beam intensity. We demonstrate that the bending dependence on the electric field in the low saturation regime has the form of a square function at low values of the field and becomes linear for higher values. For stronger saturation the curve gets the form of a square root function. The bending dependence on the beam intensity has a maximum at defined intensity. The experimental data are compared with numerical simulations, giving a good qualitative agreement. 相似文献
176.
Tan Xiaobo Yan Xin Yi Tao He Kai Shao Zhengzheng Zhou Kaikai Gao Guilong Wang Tao Zhang Jun Zhuang Zhaowen 《光子学报》2022,(2):I0002-I0002
The traditional ultrafast electric vacuum devices are usually based on the mechanism of photoelectric conversion, and their performance is restricted by factors such as material response and space-charge effect. It is difficult for the devices like microchannel plate framing cameras, Dilation X-ray Imager (DIXI) , streak cameras to achieve high temporal resolution (100 fs similar to 1 ps) and spatial resolution (similar to mu m) two-dimensional imaging. Ultrafast imaging technology based on photorefractive effect is a new ultrafast diagnostic technology, which has the advantages of high spatiotemporal resolution, all-optical, all and anti radiation. The nonequilibrium carrier lifetime of low temperature grown AlGaAs (LT-AlGaAs) can reach ps-level. The Ultrafast Response Chip (URC) made of LT-AlGaAs has the characteristics of high temporal resolution, meanwhile, good spatial performance is the other key factor for its application. In this paper, the spatial performance of LT-AlGaAs URC is experimentally studied using X-ray, generated by high-energy nanosecond pulsed laser-produced plasma, as the signal. The results show that the URC has the ability of high spatial resolution and large-scale imaging in the X-ray energy dynamic range of 120: 1. The optimal spatial resolution is >= 35 1p/mm (R) MTF = 0.1, and the imaging frame can reach 6.7 mm x 6.7 mm. The results further verify the feasibility of ultrafast diagnostic technology based on photorefractive materials. In the future, LT-AIGaAs URC will be combined with ultrafast framing technologies such as dispersion framing and polarization chirp framing to realize multi-frames and high spatiotemporal resolution two-dimensional imaging. 相似文献