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Numerical investigation of the effects of fracturing fluid parameters on hydraulic fracture propagation in jointed rock mass based on peridynamics 期刊论文  OAI收割
ENGINEERING ANALYSIS WITH BOUNDARY ELEMENTS, 2022, 卷号: 135, 页码: 38-51
作者:  
Qin, Mingqi;  Yang, Diansen;  Chen, Weizhong
  |  收藏  |  浏览/下载:30/0  |  提交时间:2022/04/11
流量对水力压裂破裂压力和增压率的影响研究 期刊论文  OAI收割
岩土力学, 2020, 卷号: 41, 期号: 7, 页码: 2411
作者:  
邵长跃;  潘鹏志;  赵德才;  姚天波;  苗书婷
  |  收藏  |  浏览/下载:26/0  |  提交时间:2021/05/25
High peak power mid-infrared 2.8 μm pulsed fiber laser 期刊论文  OAI收割
Guangzi Xuebao/Acta Photonica Sinica, 2016, 卷号: 45, 期号: 11
作者:  
Shen, Yan-Long;  Wang, Yi-Shan;  Chen, Hong-Wei;  Huang, Ke;  Tao, Meng-Meng
收藏  |  浏览/下载:16/0  |  提交时间:2016/12/23
Two side liquid-cooled and passively Q-switched disk oscillator with nanosheets in flowing CCl4 期刊论文  OAI收割
applied physics b-lasers and optics, 2016, 卷号: 122, 期号: 9
作者:  
Nie, Rongzhi;  She, Jiangbo;  Li, Dongdong;  Li, Fuli;  Peng, Bo
收藏  |  浏览/下载:20/0  |  提交时间:2016/10/14
High-peak-power sub-nanosecond intracavity KTiOPO4 optical parametric oscillator pumped by a dual-loss modulated laser with acousto-optic modulator and single-walled carbon nanotube 期刊论文  OAI收割
applied physics express, 2016, 卷号: 9, 期号: 8
作者:  
Qiao, Junpeng;  Zhao, Shengzhi;  Yang, Kejian;  Zhao, Jia
收藏  |  浏览/下载:23/0  |  提交时间:2016/10/14
Passively mode-locked Nd:YVO4 laser using a single-walled carbon nanotube saturable absorber pumped by880nm laser diode 期刊论文  OAI收割
japanese journal of applied physics, Japanese Journal of Applied Physics, 2011, 2011, 卷号: 50, 50, 期号: 12, 页码: 122703, 122703
作者:  
  |  收藏  |  浏览/下载:27/0  |  提交时间:2012/06/14
Experiments of second harmonic generation output in pulsed TEA CO 2 laser (EI CONFERENCE) 会议论文  OAI收割
High-Power Lasers and Applications V, October 18, 2010 - October 19, 2010, Beijing, China
作者:  
Li D.
收藏  |  浏览/下载:57/0  |  提交时间:2013/03/25
It is always the hot subject to realize the output of high-power laser in the range of 3-5m wavelength. This rang of wave band has greatly important applications in military because it located in the atmosphere window. Generally there are two ways to obtain this range of laser wavelength. One way is through optical parameter oscillation (OPO) from shorter laser wavelength and the other is through second harmonic generation (SHG) from longer laser wavelength. Firstly  the comparison between tow nonlinear crystals ZnGeP2 and AgGaSe2 is conducted for their nonlinear coefficient and damaging threshold in theory. The theoretical results show that the crystal AgGaSe 2 is more suitable for the SHG of pulsed TEA CO2 laser. When using pulsed TEA CO2 laser with wavelength of 9.3m to pumping AgGaSe2 SHG crystal  the wavelength of 4.65m is obtained. In the condition of repetition rate 100Hz  the upmost output power of single pulse is up to level of 1W  which corresponding efficiency of SHG is about 6%. The experimental results show that the polarization of laser beam has greatly influence on the SHG output of the crystal. Under the radiation of 3MW/cm 2 from fundamental wave and the right position for maximal SHG output in the crystal  when polarization of laser beam rotates 4.5  the SHG output of energy decrease about 30%. The research of this paper will make a foundation for further development of mid-infrared laser. 2010 Copyright SPIE - The International Society for Optical Engineering.  
The spectral feature analysis of semiconductor thin disk laser (EI CONFERENCE) 会议论文  OAI收割
Optoelectronic Materials and Devices II, November 2, 2007 - November 5, 2007, Wuhan, China
作者:  
Li J.;  Wang L.-J.;  Wang L.-J.;  Ning Y.-Q.;  Li J.
收藏  |  浏览/下载:26/0  |  提交时间:2013/03/25
The semiconductor thin disk laser is a new type of semiconductor laser. This work gives the basic operation function of semiconductor disk laser  and analyses the heat effect by the experimentally measured photoluminescence spectrum of the laser chip at different pump power and different temperature. We can see that: with increasing pump power  the thermal effects of the gain material becomes seriously and causes the saturation of carrier lifetime  so the electron-hole pair created in the absorbtion layer have no enough time to rate to one of the wells  and the non-radiative recombination happens in the barrier. When the thermal effects becomes stronger  the chip will not lasing. This phenomenon is from the smaller energy offset between barrier and quantum well. We optimize the original structure design and experimental technology. A non-absorbing AlGaAs layer who is transparent to the pumping and laser wavelength is added to confine the carriers in the quantum wells. At the same time a DBR with double reflecting band is induced to improve the absorbing efficiency of the pumping light. The single QW is replaced by the three narrow QWs  This three QWs structure can add the quantum state of QW  increase the recombination probability of carriers in the QWs and reduce the heat effect. The chemical etch equipment is also improved to control the surface unevenness to be within 50 nm.  
LD-Pumped all-solid-stated green laser with high polarization rate and high conversion efficiency (EI CONFERENCE) 会议论文  OAI收割
Optoelectronic Materials and Devices for Optical Communications, November 7, 2005 - November 10, 2005, Shanghai, China
Hao E.-J.; Tan H.-M.; Yan C.-L.; Qian L.-S.
收藏  |  浏览/下载:24/0  |  提交时间:2013/03/25
Study on LD-pumped Nd:YAG laser cutter (EI CONFERENCE) 会议论文  OAI收割
ICO20: Lasers and Laser Technologies, August 21, 2005 - August 26, 2005, Changchun, China
作者:  
Zhang G.;  Zhang G.;  Zhang G.;  Zhang J.;  Zhang J.
收藏  |  浏览/下载:25/0  |  提交时间:2013/03/25
The theory of laser cutter and the technology neck is analyzed. We can conclude that it is almost impossible to deal with the waste thick silicon wafers which are yielded in producing silicon wafers by conventional eroding or diamond cutting  when the cutting velocity equals 100mm/min  while it is also unperfected with ecumenical laser cutter without good beam quality or precise laseroptics system. It is represented that high average power and high repetition rate laser with good beam quality and precise laseroptics system are pivotal to obtain excellent cutting effect such as thick groove depth  double-layer 0.75mm thick silicon wafer can be penetrated.. The cross section is fine and the groove is narrow  rapid cutting speed  the cutting quality meets the expecting demand.  fine kerf section without considering the effect of technique. Considering laser medium thermal lens effect and thermal focal length changing with pumping power  using plano-convex high reflectivity mirror as the back cavity mirror to compensate the heat lens influence  a /4 waveplate to compensate heat -induced birefraction  utilize the Nd:YAG self- aperture effect  more than 50 W average power 1.064 um IR output is obtained with beam quality factor (M2) equals 3.19. Through the LD-Pumped Nd:YAG laser cutter we developed with short focus length negative spherical aberration focusing lens  double axis linear step motor positioning system  suitable beam expander multiplying factor  appropriate diameter of exit beam aperture  proper repetition rate  when the cutting velocity equals 400mm/min  0.75mm thick silicon wafer can be penetrated