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81.
82.
Peng Lingling Wang Yuhua Wang Zhaofeng Dong Qizheng 《Applied Physics A: Materials Science & Processing》2011,102(2):387-392
MgO:Eu3+ nanocrystals with average diameter around 15 nm were prepared via a facile combustion method under a weak reductive atmosphere
at temperature as low as 300°C. The photoluminescence spectra showed that the MgO:Eu3+ nanocrystals emit white light, the hypersensitive transition (5
D
0→7
F
j
of Eu3+) emission was prominent in the emission spectra resulting from the noinversion symmetry local site at which Eu3+ ions were located. Two kinds of luminescence sites of Eu3+ are identified by means of the fluorescence decay and site-selective spectroscopy. The excitation and absorption spectra
indicated that the absorption of surface state decreased with the increase of Eu3+ concentration, meaning that the surface defect decreased through Eu3+ doping for some of them located at the disordered sites near the surface or absorbed at the surface of MgO host. Meanwhile,
absorptivity and CIE chromaticity coordinates of all samples were measured; the results were in accordance with the excitation
and absorption spectra and photoluminescence spectra, respectively. 相似文献
83.
We show the existence of flat equal-frequency contour across the entire first Brillouin zone in two-dimensional photonic crystals. Under this condition, light diffraction can be inhibited. Moreover, the beam can be highly localized between two neighboring rows of the defect-free photonic crystal. Such a finding may have novel applications in light beam manipulations and on-chip integrated photonic devices. 相似文献
84.
85.
Lingling Qiao Fei He Chen Wang Ya Cheng Koji Sugioka Katsumi Midorikawa 《Applied Physics A: Materials Science & Processing》2011,102(1):179-183
We report on the integration of microlens and microfluidic channels in fused silica glass chip using femtosecond laser micromachining.
The main process includes three procedures: (1) femtosecond laser scanning for forming a hemispherical surface and a Y-shaped
channel in the fused silica glass; (2) chemical etching of the sample for removal of the modified areas; and (3) oxyhydrogen
(OH) flame polish for smoothening the surface of the microlens. In addition, we demonstrate that the fabricated microlens
exhibits good imaging performance with a 5× magnification, showing great potential in future lab-on-a-chip applications. 相似文献
86.
Diversified 1,4,5-substituted-2-aminoimidazoles were rapidly assembled via sequential N–H insertion and Grignard addition to α-diazoesters. Lead compounds were identified as antibiotics against Gram-positive bacteria with an MIC value as low as 2 μg/mL. 相似文献
87.
88.
Zi-Qi Zhou Qi-Rui Shui Prof. Rui-Biao Fu Yuan-Bin Fang Prof. Zu-Ju Ma Prof. Xin-Tao Wu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(51):12976-12980
The discovery of new nonlinear optical (NLO) crystals with excellent properties is in urgently demand because of their ability to generate coherent light. Herein, we report an unique NLO lead bromide formate, KCs2[Pb2Br5 (HCOO)2], which has been synthesized by a mix-solvothermal method. KCs2[Pb2Br5(HCOO)2] exhibits strong phase-matching second-harmonic generation (SHG) response (6.5×KDP), large birefringence (0.16@ 1064 nm), and a wide transparent window in most visible light and mid-IR region. Interestingly, KCs2[Pb2Br5(HCOO)2] features a polar 3D lead-bromide framework in which adjacent Pb−Br layers containing coplanar Pb6Br6 rings are not only parallel to each other, but also orient in the same direction. These oriented arrangements are responsible for the strong SHG response and large birefringence that are elucidated by both local dipole moment and theoretical calculations. This research provides a new strategy to explore subsequent NLO crystals. 相似文献
89.
Xiao Xia CHEN Fang WANG Yan Xia XU Sheng Shui HU Depatment of Chemistry Wuhan University Wuhan State Key Laboratory of Transducer Technology Chinese Academy of Sciences Beijing 《中国化学快报》2006,17(4):496-498
A novel amperometric sensor for the determination of nitric oxide was developed by coating polythionine / nafion on a glassy carbon electrode. This sensor exhibited a great enhancement to the oxidation of nitric oxide. The oxidation peak currents were linear to the concentration of nitric oxide over the wide range from 3.6×10-7 to 6.8×10-5 mol.L-1, and the detection limit was 7.2×10-8 mol.L-1. Experimental results showed that this nitric oxide sensor possessed excellent selectivity and longer stability. NO releasing from rat kidney was monitored by this sensor. 相似文献