全文获取类型
收费全文 | 100篇 |
免费 | 93篇 |
国内免费 | 3篇 |
专业分类
晶体学 | 2篇 |
数学 | 1篇 |
物理学 | 159篇 |
无线电 | 34篇 |
出版年
2024年 | 1篇 |
2023年 | 2篇 |
2022年 | 1篇 |
2021年 | 4篇 |
2020年 | 2篇 |
2019年 | 5篇 |
2018年 | 7篇 |
2017年 | 4篇 |
2015年 | 3篇 |
2014年 | 7篇 |
2013年 | 3篇 |
2011年 | 5篇 |
2010年 | 7篇 |
2009年 | 3篇 |
2008年 | 15篇 |
2007年 | 12篇 |
2006年 | 21篇 |
2005年 | 20篇 |
2004年 | 33篇 |
2003年 | 10篇 |
2002年 | 6篇 |
2001年 | 9篇 |
2000年 | 4篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1994年 | 4篇 |
1993年 | 2篇 |
排序方式: 共有196条查询结果,搜索用时 15 毫秒
161.
Sub-picosecond chirped laser pulse-induced airflow and water condensation were investigated in a cloud chamber.The results indicate that the positively chirped sub-picosecond laser pulses generate a more uniform intensity distribution inside the plasma column, leading to a weaker airflow and an elliptic-shaped snow pile. The negatively chirped sub-picosecond laser pulses generate a spark-like intensity distribution inside the plasma column, which produces a wider range of airflow and a round snow pile. The amount of snow weight and the concentration of NO_3~- are found to be dependent on the intensity distribution inside the plasma column. The visibly stronger plasma column generates much more snow and a higher concentration of NO_3~-. These experimental results provide a reference for sub-picosecond laser-induced water condensation in realistic atmospheric conditions. 相似文献
162.
Generation of few-cycle radially-polarized infrared pulses in a gas-filled hollow-core fiber
下载免费PDF全文
![点击此处可从《中国物理 B》网站下载免费的PDF全文](/ch/ext_images/free.gif)
We perform a numerical study for temporally compressing radially-polarized(RP) infrared pulses in a gas-filled hollow-core fiber(HCF). The dynamic transmission and nonlinear compression of RP pulses centered at wavelengths of0.8 m, 1.8 m, 3.1 m, and 5.0 m in HCFs are simulated. By comparing the propagation of pulses with the same optical cycles and intensity, we find that under proper conditions these pulses can be compressed down to 2–3 cycles. In the transverse direction, the spatiotemporal beam profile ameliorates from 0.8-m to 1.8-m and 3.1-m pulses before the appearance of high-order dispersion. These results show an alternative method of scaling generation for delivering RP infrared pulses in gas-filled HCFs, which can obtain energetic few-cycle pulses, and will be beneficial for relevant researches in the infrared scope. 相似文献
163.
The effect of the absolute phase of the few-cycle driving laser field on the generation and measurement of highorder harmonic attosecond pulses is investigated theoretically.We find that the generated attosecond soft-x-ray pulse is locked to the oscillations of the driving laser field,but not to the envelope of the laser pulse,and the intensity ratio of two adjacent attosenond pulses is exponential as a function of the absolute phase.Based on these results,we propose a novel method to detect the absolute phase of the driving laser field by measuring the spatial distribution of the photoelectrons induced by the attosecond soft-x-ray pulse and the driving laser field. 相似文献
164.
Anisotropic Energetic Ion Emission from Explosionof Intense Laser Irradiated Argon Clusters in a Jet
下载免费PDF全文
![点击此处可从《中国物理快报》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The interaction of an intense femtosecond laser field (~ 10^16 W/cm^2) with argon clusters in a dense jet has been studied by measuring the energy and angle distributions of emitted ions. A directional anisotropy in the ion explosion energies is observed. The experimental results indicate that the average ion energies are up to 40% in the detection direction parallel to the laser polarization higher than that perpendicular to it. The measured ion yield increases about 80%, correspondingly. The findings are interpreted by charge-dependent ion acceleration and explosion of elliptic microplasma spheres. 相似文献
165.
166.
167.
168.
169.
A novel technique for high-power extracavity pulse compression with a nonlinear solid material is demonstrated. Before spectral broadening by self-phase modulation in the solid material, a short filament generated in argon is used as a spatial filter, which works for a uniform spectrum broadening over the spatial profile. Compensated by chirped mirrors, a 15-fs pulse is generated from a 32-fs input laser pulse. A total transmission larger than 80% after the solid material is achieved. 相似文献
170.
人类在实验室可实现的激光强度极限是强场量子电动力学(QED)的重要问题。在非理想真空条件下,极端超强激光与残留的电子相互作用触发伽马光子辐射与正负电子对产生的QED级联效应,从而显著消耗激光能量,大幅降低可实现的激光峰值强度。考虑到QED级联效应与激光偏振、焦斑尺寸、脉宽长度有着密切的关系,基于囊括QED过程的粒子网格模拟方法(Particle-in-cell, PIC)对上述参数的效应进行分析,同时构建了激光场演化的自洽方程来进行解释,二者结果基本保持一致,获得的强度极限在考虑的参数范围内为1026~1027 W/cm?2。结果表明,同等情形下,圆偏振激光可激发更强的QED级联,使得激光强度上限略低于线偏振。此外,紧聚焦激光由于QED级联发生的时空间尺度更小,从而激光的吸收效应被显著抑制,进而可以实现更强的聚焦强度。对于更长脉宽的激光,由于正负电子对吸收的能量区域更加弥散,使得可实现的激光强度上限阈值有所提升。但对于超短脉宽情形(如单周期),由于QED级联的种子源电子束不能很好地被约束在激光区域,理论分析耗散的激光能量偏高。此外,在高真空度的情形下,残余电子的随机性也会对可实现激光强度产生一定的影响。研究结果可为后续开展极端强场QED实验和数100 PW级超强超短激光装置建设提供指导。 相似文献