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	Far-field focusing of laser beam based on digital image processing techniques (EI CONFERENCE) 会议论文 OAI收割 Optoelectronic Imaging and Multimedia Technology, October 18, 2010 - October 20, 2010, Beijing, China 作者: Zhao S.; Tian Y.-Z.; Liu L.-S.; Guo J.; Zhang H.-Y. 收藏 \| 浏览/下载：28/0 \| 提交时间：2013/03/25 In order to lead the laser beam transmit in the atmosphere convergently an experiment of laser focus at the distance of 450m and 300m has been operated in the outdoor place. The actual manipulations are as follows: Firstly the laser was collimated by a beam expander then the near-parallel laser beam was transmitted with a Galileo telescope system and the distance between the concave lens and the convex lens can be tuned through a precise displacement platform so the focus of the system changed due to the tiny displacement of the concave lens. Secondly the average power of the laser spot can be measured using power meter the power is 47.67mW and the standard deviation is 0.67mW while the focal length is 450m. Thirdly the energy distribution was found through the laser beam analyzer. The spot images were saved using the beam analyzer then the saved image can be processed with Matlab software afterwards. The function named EDGE and Sobel operator was used in the pre-processing of the saved image then method of median filter was used in the course of image de-noising and 53H filter was adopted in the signal analysis. The diameter of laser spot was obtained by the method above the diameter is 5.56mm and the standard deviation is 0.24mm. The spot center excursion is 0.56mm it is 10.43% of the total diameter of the laser spot. At last the key factors of the energy dissipation in the focusing system can be summarized as follows: restriction of the diffraction limit attenuation in the atmosphere geometrical aberration of optical system and the diffraction limit and the geometrical aberration are significant in the three factors above so we can reduce the impact of the both factors during the design of optical system. The reliable referenced data of the system design can be acquired through the primary experiment research. 2010 SPIE.
	Species transformation and structure variation of fulvic acid during ozonation 期刊论文 OAI收割 SCIENCE IN CHINA SERIES B-CHEMISTRY, 2008, 卷号: 51, 期号: 4, 页码: 373-378 Li Jing; Qu JuHui; Liu HuiJuan; Liu RuiPing; Zhao Xu; Hou YiNing 收藏 \| 浏览/下载：37/0 \| 提交时间：2015/08/21 fulvic acid ozone hydroxyl radicals MW distribution polar functional groups
	Effect of preozonation on the characteristic transformation of fulvic acid and its subsequent trichloromethane formation potential: Presence or absence of bicarbonate 期刊论文 OAI收割 CHEMOSPHERE, 2008, 卷号: 71, 期号: 9, 页码: 1639-1645 作者: Li, Jing; Liu, Huijuan; Zhao, Xu; Qu, Juhui; Liu, Ruiping 收藏 \| 浏览/下载：29/0 \| 提交时间：2015/08/21 ozonation bicarbonate TCMFP molecular weight (MW) distribution Fourier transform infrared (FTIR) spectrum
	A novel bottom-emitting vcsel's one-dimension array (EI CONFERENCE) 会议论文 OAI收割 Optoelectronic Materials and Devices III, October 27, 2008 - October 30, 2008, Hangzhou, China 作者: Wang L.; Wang L.; Wang L.; Liu Y.; Liu Y. 收藏 \| 浏览/下载：27/0 \| 提交时间：2013/03/25 A novel 980nm bottom-emitting VCSELs array with high power density and good beam property of Gaussian far-field distribution is reported. This array is composed of 5 symmetrically-arranged elements of 200m 150m and 100m-diameter with the center spacings of 300m and 250m respectively. The maximum power is 880mW at a current of 4A corresponding to lKW/cm2 average optical power density. The differential resistance is 0.09 with a threshold of 0.56A. The novel array is compared with a 300m-aperture-size single device and a 44 2-D array with 50m element aperture size and 250m centre spacing. The three devices have the same lasing area. The conclusion is that the novel array is better in the property of output power threshold current lasing spectra far-field distribution etc. 2008 SPIE.