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Yuci, China

Wang D.,Jinzhong University | Zheng Y.,Beijing Jiaotong University
Guangxue Xuebao/Acta Optica Sinica | Year: 2011

Dispersion of fiber may broaden the pulse width and lead to error, which must be avoided in optical communications. Using the finite element method (FEM) and considering the material dispersion of SiO2, the mode field, the effective index of fundamental mode and the dispersion property of double-cladding photonic crystal fiber (PCF) with circular arrangement are numerically simulated. Results show that the distance between large air holes and small air holes of the first layer and the diameter of large air holes determine the shape of dispersion curve when the distance and diameter of small air holes are unchanged. As some dispersion-compensating fiber, the effective mode refractive index has a transition at a wavelength, thus flattened dispersion can be realized. For example, when diameter d1=3.1 μm, d2=1 μm, distance Λ1=5 μm and Λ2=4 μm, within the wavelength range of 1.22~1.6 μm, the difference between the maximun and minimum of dispersion is less than 4 ps/(nm·km).

Wang D.,Jinzhong University | Zheng Y.,Beijing Jiaotong University
Guangxue Xuebao/Acta Optica Sinica | Year: 2013

Using the finite element method, the dispersion property, mode area and nonlinear coefficient are numerically simulated by artificially choosing the parameters of the proposed novel holey fiber. The results show that the novel fiber not only has a relatively simple structure, but also has better dispersion property. By optimizing the structure parameters, a flattened dispersion holey fiber with three zero-dispersion wavelengths (λ=1.0 μm, λ=1.53 μm, λ=1.81 μm) in the 900 nm wavelength range has been designed. These results can be used to guide the design of novel holey fiber.

Wang D.,Jinzhong University | Zheng Y.,Beijing Jiaotong University
Guangxue Xuebao/Acta Optica Sinica | Year: 2012

Using the finite element method (FEM), the mode area, confinement loss and dispersion property of a novel microstructured optical fiber (MOF) with double-cladding structure are numerically simulated, analyzed and compared with those of traditional MOF. Results show that the fiber not only has a novel structure but also has better dispersion performance than the traditional photonic crystal fiber. Through rational optimization, several flat dispersion MOFs with large mode area in the 500 nm wavelength range are designed. The novel fiber proposed will have some reference value to the subsequent theoretical study and manufacture.

Su Y.-L.,Jinzhong University
Modern Food Science and Technology | Year: 2013

The extraction of Pleurotus eryngii polysaccharides in two-phase aqueous system was investigated. The effects of PEG molecular weight, and concentrations of (NH4)2SO4 and PEG on the yield of Pleurotus eryngii polysaccharides were studied The results showed that the optimum conditions were as follows: concentration of PEG4000 21.33% and concentration of (NH4)2SO414%, under which partition coefficient of polysaccharide could reach 1.9529~2.0152 and the yield coefficient could reach 60.58~62.82 %.

Su Y.-L.,Jinzhong University
Food Science and Technology Research | Year: 2016

The aim of the present work was to develop a multimethod for the analysis of five flavonoids in G.biloba leaves. The selected flavonoids were rutin, quercetin 3-D-galactoside, baicalin, isorhamnetin and rhamnetin. Leaf extraction was sonicated by using ethanol. The extract was passed through solid-phase extraction columns. Then, the extract was analyzed by high-performance liquid chromatography coupled in line with mass spectrometry. Calibration was carried out over the concentration range of 0.5 to 50 mg/L. The calibration data presented high correlation coefficients (>0.99). The limits of detection were 4.7, 5.3, 9.7, 6.9 and 12.9 μg/L for rutin, quercetin 3-D-galactoside, baicalin, isorhamnetin and rhamnetin, respectively. Mean recoveries ranged from 66% to 72% for the HPLC-MS analysis. Reproducibility was estimated by the relative standard deviation (RSD) which ranged between 2.21 and 3.93%. Five flavonoids were found to be present in G.biloba leaves. The developed method was readily applied to quantify the flavonoids in some commercially available G.biloba leaves. © 2016, Japanese Society for Food Science and Technology.

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