2010
2010
-
Record 37 of
Title:Research on the correlation between the optical gap and chemical bond in sulphur and selenium co-doped chalco-halide glasses
Author(s):Zhu, Mingxing(1); Nie, Qiuhua(1); Wang, Xunsi(1); Dai, Shixun(1,2); Zhang, Xianghua(1,3); Shen, Xiang(1); Wang, Guoxiang(1); Lv, Xin(1)Source: Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy Volume: 75 Issue: 4 DOI: 10.1016/j.saa.2009.12.054 Published: April 2010Abstract:The Ge-Ga-Se-S-CsCl glasses were prepared by the melting-quenching method. The absorption and transmission spectrum were measured under room temperature. It is found that these glasses have high broad spectral range of transparency from visible to far-infrared region (0.4-12 μm). The relationship between the optical gap and chemical composition in terms of novel chalco-halide glasses is discussed based on the Pauling's theory model, which is using the modified heats of atomization and the coordination number of the elements, to explain this phenomena for the first time. ? 2009 Elsevier B.V. All rights reserved.Accession Number: 20100912741452 -
Record 38 of
Title:Energy transfer and mid-infrared luminescence properties of Tm3+/Dy3+ codoped chalcohalide glasses
Author(s):Zhang, Peng-Jun(1); Dai, Shi-Xun(1,2); Cao, Ying(1); Peng, Bo(2); Xu, Tie-Feng(1); Nie, Qiu-Hua(1); Zhang, Xiang-Hua(1,3)Source: Guang Pu Xue Yu Guang Pu Fen Xi/Spectroscopy and Spectral Analysis Volume: 30 Issue: 9 DOI: 10.3964/j.issn.1000-0593(2010)09-2321-05 Published: September 2010Abstract:A series of chalcohalide glasses based on the composition 0.9(Ge25Ga5S70)-0.1CsI doped with the different Tm3+/Dy3+ ions ratio were synthesized by melt-quenching technique. The absorption spectra, and mid-infrared fluorescence of different glass samples under 800 nm laser excitation were measured. The results prove that, Tm3+ is an efficient sensitizer, which can enhance the Dy3+: 2.9 μm fluorescence intensity significantly. A decrease in the intensity of 1.8 μm fluorescence and lifetimes of the Tm3+: 3F4 level occurred with increasing the concentration of Dy3+ ions from 0 to 1 Wt% where Tm3+ concentration was fixed to 0.5 Wt%. Also a wide spectral overlap between Tm3+: 1.8 μm emission and the absorption of Dy3+: 6H15/2 → 6H11/2 showed that the effective energy transfer between the two rare-earth ions was mainly attributed to the resonance energy from Tm3+: 3F4 to Dy3+: 6H11/2 level.Accession Number: 20103713225929 -
Record 39 of
Title:Effects of fabrication methods on structure of porous anodic aluminum oxide films
Author(s):Li, Zhanwang(1,2); Xia, Zhilin(1,2); Xue, Yiyu(3); Guo, Peitao(3); Zhao, Lixin(2)Source: Zhongguo Jiguang/Chinese Journal of Lasers Volume: 37 Issue: SUPPL. 1 DOI: 10.3788/CJL201037s1.0324 Published: November 2010Abstract:Highly ordered porous anodic alumina(PAA) films are fabricated with the sulfuric and oxalic acid as electrolyte and by the two-step anodization method. The crystal structure of aluminum foil before and after annealing process is examined with X-ray diffraction(XRD). Field-emission scanning electron microscope(FE-SEM) and atom force microscope(AFM) are used to observe the surface and cross morphology of PAA films. The pore diameters(20-100 nm), pore distances (50-150 nm), depths(0.2-70 μm) and densities 109-1012 /cm2 can be well controlled. The forming process and mechanism of PAA film are discussed. The effects of aluminium pre-treatments, the electrolytes type, anodizing voltages and electrolyte concentrations on PAA film's stractures are analyzed.Accession Number: 20105013489884 -
Record 40 of
Title:Identifying camera and processing from cropped JPEG photos via tensor analysis
Author(s):Li, Weihai(1); Yu, Nenghai(1); Yuan, Yuan(2)Source: Conference Proceedings - IEEE International Conference on Systems, Man and Cybernetics Volume: Issue: DOI: 10.1109/ICSMC.2010.5641757 Published: 2010Abstract:Digital image and video forensics is to detect the authenticity of digital images/videos. So far, existing algorithms are designed by exploring one or several special features, which usually result in limited performance and applicability. With the perspective of entire procedure including image acquisition and image processing, a theory of general blind image forensics is proposed in this paper. Then a new blind image forensic method is designed based on this theory to identify camera source and processing history of cropped compressed digital images. In this method, tensor decomposition analysis is applied to extract features of nonlinear operations, which come from both algorithms embedded within camera and operations done by post-software. Then, the Support Vector Machine is utilized to classify whether the target image is captured by the claimed camera and underwent the declared processing history. Experimental results show that this method has high detection accuracy, which demonstrated that our theory is correct. ?2010 IEEE.Accession Number: 20110413608170 -
Record 41 of
Title:Footwear for gender recognition
Author(s):Yuan, Yuan(1); Pang, Yanwei(2); Li, Xuelong(3)Source: IEEE Transactions on Circuits and Systems for Video Technology Volume: 20 Issue: 1 DOI: 10.1109/TCSVT.2009.2022795 Published: January 2010Abstract:Conventionally, biometrics resources, such as face, gait silhouette, footprint, and pressure, have been utilized in gender recognition systems. However, the acquisition and processing time of these biometrics data makes the analysis difficult. This letter demonstrates for the first time how effective the footwear appearance is for gender recognition as a biometrics resource. A footwear database is also established with reprehensive shoes (footwears). Preliminary experimental results suggest that footwear appearance is a promising resource for gender recognition. Moreover, it also has the potential to be used jointly with other developed biometrics resources to boost performance. ? 2010 IEEE.Accession Number: 20100312647618 -
Record 42 of
Title:Mid-infrared emission and multiphonon relaxation in Tm3+-doped Ge-Ga-Se glasses
Author(s):Zhang, Peng-Jun(1); Dai, Shi-Xun(1,2); Le, Fang-Da(1); Peng, Bo(2); Xu, Tie-Feng(1); Nie, Qiu-Hua(1); Zhang, Xiang-Hua(1,3)Source: Guang Pu Xue Yu Guang Pu Fen Xi/Spectroscopy and Spectral Analysis Volume: 30 Issue: 6 DOI: 10.3964/j.issn.1000-0593(2010)06-1464-05 Published: June 2010Abstract:A series of chalcogenide glasses based on the composition Ge30Ga5Se65 (at.%) doped with the different Tm3+ ions were synthesized by melt-quenching technique. The refractive indexes, Raman spectra, absorption spectra, near-and mid-infrared fluorescence, and lifetimes of glass samples under 800 nm laser excitation were measured. The intensity parameters Ωi(i=2, 4, 6), transition probabilities, branching ratios and radiative lifetimes have been predicted for Tm3+ ions in samples by using the Judd-Ofelt theory. The near-infrared emission spectra at 1.23, 1.48 and 1.8 μm were observed and their quantum efficiencies were evaluated respectively in glass doped with 1 Wt% Tm3+-ions under 800 nm excitation. The mid-infrared fluorescence spectra were investigated with the different Tm3+ ion concentration under 800 nm excitation. The multiphonon relaxation rate of Tm3+: 3H5 → 3F4 by the measured and calculated lifetimes, and the relative parameters of W(0) and α in Ge30Ga5Se65 glass were evaluated. Results show that the multiphonon relaxation rates were significantly lower than other glasses due to the lower maximum phonon energy, so the selenide glasses are promising as host materials for doping by rare earth ions and for preparation of mid-infrared optical elements.Accession Number: 20102513030955 -
Record 43 of
Title:Nanosize structural modifications with polarization functions in ultrafast laser irradiated bulk fused silica
Author(s):Mishchik, K.(1); Cheng, G.(1,2); Huo, G.(2); Burakov, I.M.(1); Mauclair, C.(1); Mermillod-Blondin, A.(3); Rosenfeld, A.(3); Ouerdane, Y.(1); Boukenter, A.(1); Parriaux, O.(1); Stoian, R.(1)Source: Optics Express Volume: 18 Issue: 24 DOI: 10.1364/OE.18.024809 Published: November 22, 2010Abstract:Laser-induced self-organization of regular nanoscale layered patterns in fused silica is investigated using spectroscopy and microscopy methods, revealing a high presence of stable broken oxygen bonds. Longitudinal traces are then generated by replicating static irradiation structures where the nanoscale modulation can cover partially or completely the photoinscribed traces. The resulting birefringence, the observed anisotropic light scattering properties, and the capacity to write and erase modulated patterns can be used in designing bulk polarization sensitive devices. Various laser-induced structures with optical properties combining guiding, scattering, and polarization sensitivity are reported. The attached polarization functions were evaluated as a function of the fill factor of the nanostructured domains. The polarization sensitivity allows particular light propagation and confinement properties in three dimensional structures. ? 2010 Optical Society of America.Accession Number: 20104913463904 -
Record 44 of
Title:L1-norm-based 2DPCA
Author(s):Li, Xuelong(1); Pang, Yanwei(2); Yuan, Yuan(3)Source: IEEE Transactions on Systems, Man, and Cybernetics, Part B: Cybernetics Volume: 40 Issue: 4 DOI: 10.1109/TSMCB.2009.2035629 Published: August 2010Abstract:In this paper, we first present a simple but effective L1-norm-based two-dimensional principal component analysis (2DPCA). Traditional L2-norm-based least squares criterion is sensitive to outliers, while the newly proposed L1-norm 2DPCA is robust. Experimental results demonstrate its advantages. ? 2006 IEEE.Accession Number: 20102913089354 -
Record 45 of
Title:Scattering loss of a new fluid state laser material
Author(s):Gui, Luo(1); Hou, Chaoqi(2); Peng, Bo(2); Fan, Dianyuan(1); Wei, Wei(2)Source: Zhongguo Jiguang/Chinese Journal of Lasers Volume: 37 Issue: 10 DOI: 10.3788/CJL20103710.2605 Published: October 2010Abstract:The scattering loss of a new mixed fluid state laser material varying with refractive index and temperature is studied experimentally. A platform of laser amplifier is established, on which the laser performance of the new material is shown by a comparison between the fluid state laser material and Nd-glass solid laser material. Experimental results show that the fluid state laser material possesses typical laser gain, but its scattering loss is sensitive to the variation of refractive index and temperature. The scattering loss can be controlled under 0.0047 cm-1 with accurate refractive index matching. The results above indicate that the method of refractive index matching is able to ensure an acceptable scattering loss of this new type of fluid state laser material, so this new material has a potential ability in high power laser systems.Accession Number: 20104713408834 -
Record 46 of
Title:Silver nanocrystals incorporated tellurite glass for highly nonlinear fiber development
Author(s):Zhou, Zhiguang(1,3); He, Jianli(1,3); Lin, Aoxiang(1,2); Guo, Haitao(1); Lu, Min(1); Wei, Wei(1); Peng, Bo(1)Source: 2010 Asia Communications and Photonics Conference and Exhibition, ACP 2010 Volume: Issue: DOI: 10.1109/ACP.2010.5682559 Published: 2010Abstract:7.5wt% silver nanocrystals were successfully incorporated into an easily-fiberized tellurite glass with composition of 75TeO2-20ZnO- 5Na2O (mol%). Surface Plasmon resonance absorption peak was found to be centered at around 552nm as the indirect evidence of silver nanocrystals with an average radius of 2.18nm. ?2010 IEEE.Accession Number: 20110713663516 -
Record 47 of
Title:An integrated aurora image retrieval system: AuroraEye
Author(s):Fu, Rong(1); Gao, Xinbo(1); Li, Xuelong(2); Tao, Dacheng(3); Jian, Yongjun(1); Li, Jie(1); Hu, Hongqiao(4); Yang, Huigen(4)Source: Journal of Visual Communication and Image Representation Volume: 21 Issue: 8 DOI: 10.1016/j.jvcir.2010.06.002 Published: November 2010Abstract:With the digital all-sky imager (ASI) emergence in aurora research, millions of images are captured annually. However, only a fraction of which can be actually used. To address the problem incurred by low efficient manual processing, an integrated image analysis and retrieval system is developed. For precisely representing aurora image, macroscopic and microscopic features are combined to describe aurora texture. To reduce the feature dimensionality of the huge dataset, a modified local binary pattern (LBP) called ALBP is proposed to depict the microscopic texture, and scale-invariant Gabor and orientation-invariant Gabor are employed to extract the macroscopic texture. A physical property of aurora is inducted as region features to bridge the gap between the low-level visual features and high-level semantic description. The experiments results demonstrate that the ALBP method achieves high classification rate and low computational complexity. The retrieval simulation results show that the developed retrieval system is efficient for huge dataset. ? 2010 Elsevier Inc. All rights reserved.Accession Number: 20104313334155 -
Record 48 of
Title:Near- and mid-infrared spectroscopic properties of Tm3+-doped Ge-Ga-S-CsI glasses
Author(s):Zhang, Pengjun(1); Dai, Shixun(1,2); Peng, Bo(2); Xu, Tiefeng(1); Nie, Qiuhua(1); Zhang, Xianghua(1,3); Wang, Xunsi(1)Source: Zhongguo Jiguang/Chinese Journal of Lasers Volume: 37 Issue: 2 DOI: 10.3788/CJL20103702.0554 Published: February 2010Abstract:Tm3+-doped chalcogenide glasses in Ge-Ga-S-CsI system were prepared and the properties of glasses including density, absorption spectrum, emission spectra and fluorescence life in the near- and mid-infrared spectral region under 800 nm excitation were measured. The optical parameters such as intensity parameter Ωi (i=2, 4, 6), predicted spontaneous A, radiative transition rate β and lifetime τrad of Tm3+ in Ge-Ga-S-CsI glasses and so on by means of Judd-Ofelt theory according to absorption spectrum were calculated. The fluorescence spectra were investigated with the different Tm3+ ion concentration under 800 nm excitation. Also, the emission cross-section at 1.8 μm and 3.8 μm was found using the theory of McCumber and the Futchbauer- Ladenburg equation respectively.Accession Number: 20101412826745