Chu X.,Zhejiang Agriculture And forestry University |
Wen W.,Huaihua University
Optics Express | Year: 2014
Quantitative description of the self-healing ability of a beam is very important for studying or comparing the self-healing ability of different beams. As describing the similarity by using the angle of two infinite-dimensional complex vectors in Hilbert space, the angle of two intensity profiles is proposed to quantitatively describe the self-healing ability of different beams. As a special case, quantitative description of the self-healing ability of a Bessel-Gaussian beam is studied. Results show that the angle of two intensity profiles can be used to describe the self-healing ability of arbitrary beams as the reconstruction distance for quantitatively describing the self-healing ability of Bessel beam. It offers a new method for studying or comparing the self-healing ability of different beams. © 2014 Optical Society of America.
Chen W.,Huaihua University
Dalton Transactions | Year: 2015
Sr2+ and Si4+ ion doped LaAlO3:Eu phosphors were synthesized through a high-temperature solid-state reaction route. Their phase component and photoluminescence properties were investigated. Under ultraviolet (UV) light excitation, the phosphors show simultaneously blue emission of the Eu2+ ion and orange-red emission of the Eu3+ ion. The relative emission intensity of both Eu2+ and Eu3+ ions can be tuned by changing the doping concentration of the Sr2+, Si4+ and Eu3+ ions. In contrast to the Sr2+ ion, the incorporation of Si4+ ion can effectively enhance the emission of Eu2+. The optimal doping concentration of the Eu3+ and Si4+ ions are about 0.02 and 0.03, respectively. The results indicate that the phosphor may be a potential candidate for white LED lighting applications. © The Royal Society of Chemistry 2015.
Li S.H.,Huaihua University
Zhong yao cai = Zhongyaocai = Journal of Chinese medicinal materials | Year: 2010
To study the chemical constituents from Lithocarpus polystachyus. Compounds were isolated and purified with silica gel, and there structures were identified by chemical property and spectral data. Nine compounds were isolated as phloridzin (I), phloretin (II), dihydrochalcone-2'-beta-D-glucopyranoside (III), daucossterol (IV), beta-sitosterol (V), quercetin (VI), luteolin (VII), quercitrin (VI), oleanolic acid (IX). Compounds II, IV - IX are isolated from this plant for the first time.
Ding X.,Huaihua University |
Chen G.,Hunan Agricultural University
Optics and Laser Technology | Year: 2014
We propose an optical color image cryptosystem based on position multiplexing technique and phase truncation operation. Compared with the reported color image encryption method, we employ the position multiplexing technique to encrypt the color image in only one spatial channel. Meanwhile, our proposed method can maintain the nonlinear characteristic of the cryptosystem and avoid various types of the currently existing attacks, especially the iterative attack. Simulation results are presented to demonstrate the security and robustness performance of the proposed method. © 2013 Elsevier Ltd.
Deng X.,Huaihua University
Optics Letters | Year: 2015
I comment on the recent Letter by Cai et al. [Opt. Lett. 40, 475 (2015).], in which the authors claimed that the method can resist the special attack. However, I think their attack analysis and algorithm are ill-considered and worth discussing. © 2015 Optical Society of America.