Wu L.,Changchun University of Science and Technology |
Li T.,Changchun University of Science and Technology |
Li Z.,Changchun University of Science and Technology |
Qiao Z.,Changchun University of Science and Technology |
And 4 more authors.
Guangxue Xuebao/Acta Optica Sinica | Year: 2014
In order to improve the optical power of 980 nm semiconductor laser, the extension waveguide is added to the epitaxy structure. The laser barrier layer thickness and the waveguide component are optimized. The light field is shifted to the center constituted by both the active region and extension waveguide layer from the center of quantum well with symmetric pattern, the limiting factors is reduced, and the output power is increased. The optical power density at output window is decreased since the optical field in vertical direction is enlarged, and thus the catastrophic optical damage is avoided. ©, 2014, Guangxue Xuebao/Acta Optica Sinica. All right reserved.
Liu X.L.,Hefei General Machinery Research Institute |
Chen X.D.,Hefei General Machinery Research Institute |
Wang B.,Hefei General Machinery Research Institute |
Fan Z.C.,Hefei General Machinery Research Institute |
Zhuang Q.W.,Changchun Research Institute for Mechanical Science Co.
Procedia Engineering | Year: 2015
The research situation of material testing apparatus in hydrogen is reviewed. Lots of research on the materials testing apparatus in high pressure hydrogen at ambient temperature was reported. However, few detail the apparatus for material testing in hydrogen at high temperature, especially for dynamic testing. A new apparatus for material testing in hydrogen at the elevated temperature (300∼600°C) has been developed. The apparatus consists of a pressure vessel and a control system which can be divided into three subsystem: temperature control system, hydrogen pressure control system and coolant system. A heating furnace composed of lower and upper resistance wires for temperature uniformity of the specimen was installed in the pressure vessel. The temperature was measured by upper and lower thermocouples attached to the specimen. Gas pressure in the vessel was controlled by inlet and outlet solenoid valve. An external loading system was employed for loading on the specimen. The elongation of specimen was measured by grating scale. The outside wall of the vessel was cooled by circulating water to protect against thermal degradation of seal ring. © 2015 The Authors.
Pei Y.-C.,Jilin University |
Pei Y.-C.,Changchun Research Institute for Mechanical Science Co. |
Tan Q.-C.,Jilin University |
Zhuang Q.-W.,Changchun Research Institute for Mechanical Science Co. |
Ma J.-C.,Changchun Research Institute for Mechanical Science Co.
International Journal of Mechanical Sciences | Year: 2013
A connection disk rotating at constant speed under temperature rise and transmitted torque at the inner and outer clamped edges is modeled using a nonlinear elastic-plastic stress-strain relation, and the elastic-plastic effective stress in Von Mises yield criterion is obtained efficiently by the finite difference method with a closed-form initial predicted value. Effects of rotational speed, edge temperature rises, transmitted torque and their couplings on the elastic-plastic stresses of the connection disk are studied. It is seen that the effective stress increases generally with the edge temperature rises, and the outer edge temperature rise increases the maximum effective stress more remarkably than the inner edge one; the maximum elastic-plastic effective stress occurs at either the inner edge or outer edge. © 2013 Elsevier Ltd.
Liu X.,Hefei General Machinery Research Institute |
Liu X.,National Safety Engineering Technology Research Center for Pressure Vessels and Pipeline |
Chen X.,Hefei General Machinery Research Institute |
Chen X.,National Safety Engineering Technology Research Center for Pressure Vessels and Pipeline |
And 7 more authors.
Hanjie Xuebao/Transactions of the China Welding Institution | Year: 2016
A new testing apparatus in hydrogen environment was developed for studying the degradation of material properties by hydrogen which is the most common type of damages induced by gas. The temperature uniformity of specimen is the key to ensure the creditability and accuracy of the testing results. Another water-cooling structure was added on the top of the pressure vessel to take away the excessive thermal gathered at the upper specimen. A new fuzzy-PID control algorithm was proposed to enhance the accuracy of temperature uniformity. The fuzzy algorithm is used to set the power upper limit of both upper and lower resistive heater respectively, and then the traditional PID algorithm is used to control the power of each resistive heater separately. The experiment results indicate that the new heater structure and fuzzy-PID control algorithm improved the temperature uniformity of the specimen, and the temperature difference between upper and lower of the specimen was control within ±1℃, which meet the demands of material performance testing. © 2016, Editorial Board of Transactions of the China Welding Institution, Magazine Agency Welding. All right reserved.