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Zhengzhou, China

Guo X.,Zhengzhou University | Zhan Q.,Zhengzhou University | Jin G.,Henan Hanwei Electronics Co. | Li G.,Zhengzhou University | Zhan Z.,Zhengzhou University
Journal of Materials Science: Materials in Electronics | Year: 2014

Fluorine-doped nanocrystalline tin oxide materials were prepared via sol–gel method with tin dichloride dihydrate (SnCl2·2H2O) as the precursor and hydrofluoric acid as the dopant source. The materials were characterized by Fourier transform infrared spectra, scanning electron microscopy, energy-dispersive X-ray spectrometry and X-ray diffraction. Hot-wire semiconductor metal oxide gas sensor was fabricated based on F-doped tin dioxide (SnO2). Gas-sensing properties were tested and gas-sensing mechanism was discussed. The results showed that the average particle sizes of F-SnO2 increased from 8 to 20 nm with increasing atomic ratio of n(F)/n(Sn) from 0 to 6.14 %. The optimal sensor response to 1,000 ppm hydrogen (H2) was improved from 69 to 800 mV at 4.43 %. The response and recovery time were <5 and 30 s, respectively. The mechanism analysis showed that the electrical conductivity of SnO2 was obviously increased by doping fluorine (F) because of fluorine ions occupying the position of oxygen in the SnO2 lattice creating free electrons, thus the response of gas sensor to H2 was significantly improved. © 2014, Springer Science+Business Media New York. Source

Henan Hanwei Electronics Co. | Date: 2013-05-07

Alarms, namely, burglar alarms, fire alarms, personal security alarms; proximity sensors; alarm and alert systems, namely, alarm monitoring system that alerts the customer when an intruder enters or other sensors detect a smoke, gas or other life threatening environmental conditions; hygrometers; air analysis apparatus; gas testing instruments; detectors, namely, fire and smoke detectors, carbon monoxide detectors; semiconductor devices.

Henan Hanwei Electronics Co. | Date: 2012-12-12

Electric sensors; detectors, namely, carbon monoxide detectors, carbon dioxide detectors; fire and smoke detectors; gas detectors for detecting the presence of gas; alarms, namely, alarm installations and alarms, alarms for the detection of inflammable gases, smoke alarms; gas testing instruments; air analysis apparatus; electrical inductors; hygrometers; measuring apparatus; smoke detectors; burglar alarms.

Henan Hanwei Electronics Co. | Date: 2011-06-28

Air analysis apparatus; Alarm installations and alarms; Apparatus for testing gas, liquids and solids; Gas detectors for detecting the presence of gas; Gas sensors for measuring gas concentration; Gas testing instruments; Hygrometers; Semiconductor devices; Technical measuring, testing and checking apparatus and instruments for measuring, testing and checking the temperature, pressure, quantity and concentration of gas and liquids; Warning devices, namely, bells.

Zhang H.,Kaifeng Advanced Technical Schools | Guo Z.,Zhongyuan University of Technology | Qi Z.,Henan Hanwei Electronics Co. | Wang J.,Henan Hanwei Electronics Co.
Proceedings - 2012 International Conference on Computer Science and Information Processing, CSIP 2012 | Year: 2012

In this paper, we proposed a defect detection algorithm based on Discrete Fourier Transform (DFT) and optimal threshold method, mainly aiming at detecting bubble, stone, and crack of glass. Firstly, the test images are pre-processed using median filter. Then the defect region is highlighted by spectral residual approach in Discrete Fourier Transform (DFT). Finally, the optimal threshold, using which the defect region is segmented, is determined by multiple iterations. Experimental results demonstrate the proposed detection algorithm can detect and localize the defect region with high accuracy and better practicability. © 2012 IEEE. Source

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