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Portevin-Le Chatelier effect in wrought Ni-based superalloys: Experiments and mechanisms 期刊论文  OAI收割
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY, 2020, 卷号: 51, 页码: 16-31
作者:  
Cui, Chuanyong;  Zhang, Rui;  Zhou, Yizhou;  Sun, Xiaofeng
  |  收藏  |  浏览/下载:45/0  |  提交时间:2021/02/02
Adaptive Wiener filtering with Gaussian fitted point spread function in image restoration (EI CONFERENCE) 会议论文  OAI收割
2011 IEEE 2nd International Conference on Software Engineering and Service Science, ICSESS 2011, July 15, 2011 - July 17, 2011, Beijing, China
作者:  
Yang L.;  Zhang X.;  Zhang X.;  Zhang X.;  Yang L.
收藏  |  浏览/下载:49/0  |  提交时间:2013/03/25
In the imaging process of the space remote sensing camera  there was degradation phenomenon in the acquired images. In order to reduce the image blur caused by the degradation  the remote sensing images were restored to give prominence to the characteristic objects in the images. First  the frequency-domain notch filter was adopted to remove strip noises in the images. Then using the ground characters with the knife-edge shape in the images  the point spread function of the imaging system was estimated. In order to improve the accuracy  the estimated point spread function was corrected with Gaussian fitting method. Finally  the images were restored using the adaptive Wiener filtering with the fitted point spread function. Experimental results of the real remote sensing images showed that almost all strip noises in the images were eliminated. After the denoised images were restored  its variance and its gray mean gradient increased  also its laplacian gradient increased. Restoration with Gaussian fitted point spread function is beneficial to interpreting and analyzing the remote sensing images. After restoration  the blur phenomenon of the images is reduced. The characters are highlighted  and the visual effect of the images is clearer. 2011 IEEE.  
Experiment analysis of CO2 laser disturbance on long-wave infrared HgCdTe detector (EI CONFERENCE) 会议论文  OAI收割
2011 International Conference on Electric Information and Control Engineering, ICEICE 2011, April 15, 2011 - April 17, 2011, Wuhan, China
作者:  
Wang S.-W.
收藏  |  浏览/下载:27/0  |  提交时间:2013/03/25
Theoretical analysis and experimental study were carried out on the high-power CO2 laser disturbance to long-wave infrared (LWIR) HgCdTe detector in this paper. Based on the practical parameters of experiment  the theoretical model of temperature-rise is adopted to calculate the variation of the temperature with the time and the power of laser for laser irradiation on the detector. After that  the damage threshold is 110W/cm2. This experimental phenomenon well agrees with the results predicted by the theoretical calculation. The conclusions have a certain reference value for the laser defense of detector. 2011 IEEE.  the high-power laser damage mechanism to LWIR detector is discussed  and compares with the experimental results of laser irradiation the detector on the distance of 15km. The theoretical and experimental results demonstrate that the interference threshold of the detector is 20.5W/cm 2  
Grayscale control algorithm based on optokinetic nystagmus (EI CONFERENCE) 会议论文  OAI收割
2010 3rd International Conference on Advanced Computer Theory and Engineering, ICACTE 2010, August 20, 2010 - August 22, 2010, Chengdu, China
Chen Y.-S.; Gao H.-B.; Su W.-X.; Wang M.
收藏  |  浏览/下载:27/0  |  提交时间:2013/03/25
In order to reduce trailing phenomenon for moving image in FPD (Flat Panel Display)  Then  Finally  grayscale control algorithm is proposed that simulates CRT (Cathode Ray Tube) grayscale rendition process. First  based on algorithm derivation  implemented main program with VHDL (Very-High-Speed Integrated Circuit Hardware Description Language) is presented and specific rendition process is described. Experimental results indicate image quality is evidently improved and proposed algorithm reduces trailing phenomenon nearly 90%  after the reason of trailing phenomenon for moving image is introduced  algorithm realization steps and compared experiment results of traditional and proposed FPD grayscale control algorithm are discussed  when FPD displays moving image  work processes of human eyes are illuminated and grayscale rendition of a pixel is obtained  according with eyes reflection mechanism and programs can correctly implement on circuit board. 2010 IEEE.  when seeing moving image on CRT and FPD  
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:30/0  |  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.