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Yang S.,Tsinghua University | Yang S.,Beijing Institute of Technology | Wei X.,Beijing Glass Research Institute | Yan P.,Tsinghua University
Yadian Yu Shengguang/Piezoelectrics and Acoustooptics | Year: 2012

The development of fiber-optic pressure sensor applied to the weigh-in-motion (WIM) field is discussed from a practical viewpoint in this paper. The research of fiber-optic pressure sensor based on intensity-modulation, wavelength-modulation, and phase-modulation is introduced respectively. The principles, structures, advantage and disadvantage are also described for these sensors. By comparing the characteristics of various fiber-optic pressure sensors, it has been found that the wavelength-modulated fiber-optic pressure sensor would become a mainstream of research for WIM.

Zhang H.,CAS Shanghai Institute of Ceramics | Zhang H.,University of Chinese Academy of Sciences | Zhang Q.,Beijing Glass Research Institute | Zhao X.,CAS Shanghai Institute of Ceramics | And 3 more authors.
Applied Physics Letters | Year: 2013

Optical properties of A-site disordered Na0.5Bi 0.5TiO3-x%BaTiO3 (NBT-xBT) single crystals with three typical compositions were studied systematically. Refractive index as a function of wavelength was measured by Spectroscopic ellipsometry, and modified Sellmeier dispersion equations were obtained by the least square fitting. High optical transmittance (65%) over a wide transparent region (from 400 to 6000 nm) has been found in NBT-7.5BT, much higher than that of NBT and NBT-5BT. Optical band gap energies were calculated using the absorption coefficient through Tauc equation. With increasing BT content, refractive index and absorption coefficient decrease, while transmission and band gap energy increase. © 2013 AIP Publishing LLC.

Yuan H.,Wuhan University of Technology | Yuan H.,Beijing Glass Research Institute | Li J.,Wuhan University of Technology | Shen Q.,Wuhan University of Technology | Zhang L.,Wuhan University of Technology
Journal Wuhan University of Technology, Materials Science Edition | Year: 2015

Zirconium oxide (ZrO2) and boron carbide (B4C) were added to ZrB2 raw powders to prepare ZrB2 porous ceramics by reactive spark plasma sintering (RSPS). The reactions between ZrO2 and B4C which produce ZrB2 and gas (such as CO and B2O3) result in pore formation. X-Ray Diffraction results indicated that the products phase was ZrB2 and the reaction was completed after the RSPS process. The porosity could be controlled by changing the ratio of synthesized ZrB2 to raw ZrB2 powders. The porosity of porous ceramics with 20 wt% and 40 wt% synthsized ZrB2 are 0.185 and 0.222, respectivly. And dense ZrB2-SiC ceramic with a porosity of 0.057 was prepared under the same conditions for comparison. The pores were homogeneously distributed within the microstructure of the porous ceramics. The results indicate a promising method for preparing porous ZrB2-based ceramics. © 2015, Wuhan University of Technology and Springer-Verlag Berlin Heidelberg.

Tian Y.-L.,National Glassware Products Quality Supervision and Inspection Center | Tian Y.-L.,Beijing University of Technology | Zhan M.,Beijing University of Technology | Li Y.-M.,National Glassware Products Quality Supervision and Inspection Center | And 3 more authors.
Key Engineering Materials | Year: 2016

This paper described three methods for measuring high temperature resistivity of glass including their basic principles, advantages and disadvantages so as to provide a reference for measurement. The effects of electrode and voltage on high temperature resistivity were studied. Accuracy of measurement results of plate electrodes is better than wire electrodes. The resistivity of molten glass decreased with increasing AC voltage. Measurement results are stable when the voltage is less than 10 V, but when the voltage exceeds than 40 V, Joule heating effect will be generated resulting in smaller measurement values. In addition, high alkali aluminosilicate glass as object is used to introduce test procedure of temperature resistivity and explore the relationship between high temperature resistivity and alkali metal. Results show that high alkali aluminosilicate glass resistivity decreases with increasing temperature, and the effect of K2O on high tempearature resistivity is more pronounced. © 2016 Trans Tech Publications, Switzerland.

Shi L.,Tsinghua University | Zhang W.,Tsinghua University | Xing W.,Tsinghua University | Li Z.,Beijing Glass Research Institute | And 3 more authors.
Zhongguo Jiguang/Chinese Journal of Lasers | Year: 2010

During the fabrication process of hollow-core Bragg fibers, outer diameter variations would be induced unavoidably, which lead to band gap shifts of the one dimensional photonic crystal structures in the fiber claddings, impacting their transmission characteristics severely. The mode transmission characteristics of hollow-core Bragg fibers with slowly sine variation in outer diameter have been investigated. The simulation results show that, despite the transmission characteristics are different between different mode classes and the mode losses are different between modes in the same mode class with different orders, the diameter variation tolerances are almost the same. In the case calculated, the diameter variation tolerances of the TE0n mode are about 9%, and 6%~7% for the TM0n, HE and EH modes. The method deployed can be used for any diameter variations and structure parameters.

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