Henan Hanwei Electronics Co.

Zhengzhou, China

Henan Hanwei Electronics Co.

Zhengzhou, China
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Liang X.,Jilin University | Liang X.,Henan Hanwei Electronics Co. | Jin G.,Henan Hanwei Electronics Co. | Liu F.,Jilin University | And 4 more authors.
Ceramics International | Year: 2015

In this study, indium oxide (In2O3) hollow nanofibers were synthesized through a two-step process. In2O3 solid nanofibers were prepared by electrospinning, and 10% HNO3 was used to corrode these nanofibers to obtain In2O3 hollow nanofibers. Moreover, the effects of corrosion on the morphology and acetone-sensing properties of In2O3 nanofibers were investigated. In2O3 nanofibers that were corroded for 2h displayed hollow structures and exhibited a high response (resistance ratio) of 151 to 5ppm of acetone at 300°C. The minimum detection limit was 20ppb. The hollow In2O3 nanofibers also exhibited high selectivity to acetone along with negligible cross-responses to interference gases at 300°C, These gases include NO2, H2, CO, benzene, p-xylene, and toluene. The strong response to acetone was attributed to the enhanced accessibility of gas for gas-sensing reactions due to the hollow morphology. © 2015 Elsevier Ltd and Techna Group S.r.l.

Zhang X.,Henan Hanwei Electronics Co. | Gu R.,Zhengzhou Winsen Electronic Technology Co. | Zhao J.,Henan Hanwei Electronics Co. | Jin G.,Henan Hanwei Electronics Co. | And 2 more authors.
Journal of Materials Engineering and Performance | Year: 2015

Nanosized In2O3 powders with different particle sizes were prepared by the microemulsion synthetic method. The effects of particle size on the gas-sensing and catalytic properties of the as-prepared In2O3 were investigated. Reductions in particle size to nanometer levels improved the sensitivity and catalytic activity of In2O3 to i-C4H10 and C2H5OH. The sensitivity of nanosized In2O3 (<42 nm) sensors to i-C4H10, H2 and C2H5OH was 2-4 times higher than that of chemically precipitated In2O3 (130 nm) sensor. A nearly linear relationship was observed between the catalytic activity and specific surface area of In2O3 for the oxidation of i-C4H10 and C2H5OH at 275 °C. The relationship between gas sensitivity and catalytic activity was further discussed. The results of this work reveal that catalytic activity plays a key role in enhancing the sensitivity of gas-sensing materials. © 2015 ASM International

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.

Ma X.,Jilin University | Cong H.,Jilin University | Mu R.,Jilin University | Fan H.,Jilin University | And 6 more authors.
Chinese Journal of Sensors and Actuators | Year: 2011

A non-contact temperature measurement platform was introduced to measure operating temperature of tiny chips according to the theory about the same radiated power for a certain object at the same temperature. On this platform, the relationship between surface temperature and operating current and temperature contours of a micro planar-ceramic sensor (Hanwei Electronics Co., Ltd.) was defined. On this base, the optimum operating temperature of In 2O 3 nanofibers was determined. The sensitive properties of In 2O 3 sensor were studied at this optimum operating temperature to verify the validity of the temperature measurement system. This method can further extend to the surface temperature measurement of other micro-structure or MEMS devices.

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.

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: 2013-05-07

Alarms; sensors; alarm and alert systems; hygrometers; air analysis apparatus; gas testing instruments; detectors; semiconductor devices.

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.

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