Li B.,Tianjin University of Technology |
Li B.,Tianjin Maiman Laser Technology Co. |
Lei P.,Shenyang Academy of Instrumentation Science Co |
Sun B.,Tianjin Maiman Laser Technology Co. |
Bai Y.B.,Tianjin University of Technology
Applied Optics | Year: 2017
A high-efficiency, high-repetition-rate Nd:YVO4 self-Raman laser at the first-Stokes wavelength of 1176 nm pumped by a wavelength-locked 913.9 nm laser diode is presented. An output power of 9.4 W with a pulse repetition rate of 140 kHz was also generated under the absorbed pump power of 29.6 W for the incident pump power of 36 W, corresponding to a diode-to-Stokes conversion efficiency of 31.8%. This is to our knowledge the highest optical to optical efficiency and output power of a laser diode end-pumped Nd:YVO4 self-Raman laser at 1176 nm. © 2017 Optical Society of America.
Adewale I.D.,Northumbria University |
Tian G.Y.,Northumbria University |
Tian G.Y.,University of Electronic Science and Technology of China |
Dong S.H.,Shenyang Academy of Instrumentation Science Co |
And 3 more authors.
Studies in Applied Electromagnetics and Mechanics | Year: 2015
This paper focuses on defect characterisation independent of the lift-off effects using lift-off point of intersection (LOI) and the separation of these two parameters in pulsed eddy current (PEC) measurements for ferrous and nonferrous materials. It reveals, amongst other things, that the first order derivative of the normalised PEC response maintains the LOI feature, which otherwise is not apparent in ferromagnetic materials using current methods; lift-off effects in ferrous materials vary strongly with the second order derivative of the normalised PEC response and the LOI can be used for defect estimation in a magnetic sensor-based PEC. These two characteristics provide a means of separating lift-off effects from the defect. © 2015 The authors and IOS Press. All rights reserved.
Wang R.,Shenyang Academy of Instrumentation Science co |
Lu S.,Shenyang Academy of Instrumentation Science co |
Yin X.,Shenyang Academy of Instrumentation Science co |
Zhao S.,Shenyang Academy of Instrumentation Science co |
Sun Y.,Shenyang Academy of Instrumentation Science co
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2016
By using Nb2O5 and SiO2 as the coating material, a 152 layers (12 cavities) bandpass film stack with steep edge on both sides was designed. Multiple thickness control methods, including direct optical monitoring control and time control were used in coating strategy. To confirm the feasibility of this coating strategy, a process simulation was performed using Simulator software, and the simulation result indicated that relative thickness errors for all layers were less than ±0.1%. A bandpass filter with this film stack on one side was manufactured by using a plasma assisted reactive magnetic sputtering coating machine. The measuring result shows that the peak transmittance of the filter (without AR on backside) is up to 95.4%, and the steepness of both blocking slope are less than λ/100. © 2016 SPIE.
Yang Y.B.,Dalian Maritime University |
Liu Y.,Dalian Maritime University |
Kong X.F.,Shenyang Academy of instrumentation Science Co
Advanced Materials Research | Year: 2014
Using SPSS software and time series analysis method, we research on the influence of demographic dividend factors on Liaoning province dependency ratio indicators. The results found that a major determinant of regional economy, which is in the demographic dividend period, is per capita consumption and the dependency ratio. © (2014) Trans Tech Publications, Switzerland.
Ma Y.,Shenyang Academy of Instrumentation Science Co |
Bai X.F.,Shenyang Academy of Instrumentation Science Co
Applied Mechanics and Materials | Year: 2014
The precision dicing machine is adopted as the research object in the paper, the technology of grating sensor is selected to overcome the shortcoming of traditional compensation methods for inaccurate return compensate. The measurement is done through the grating sensor, with the aid of neural network feedback method, the fitting and compensation of the data measured by the grating sensor is completed, the deviation caused by vibration during the spindle run-time is eliminated. And the purpose of improving the precision of spindle is realized. © (2014) Trans Tech Publications, Switzerland.
Liu F.,Shenyang Academy of Instrumentation Science Co |
Zhao Q.,Shenyang Academy of Instrumentation Science Co |
Ma H.F.,Shenyang Academy of Instrumentation Science Co
Advanced Materials Research | Year: 2013
Due to working in natural environment in a long term and dust deposited on the surface, air cooling radiator turns to a lower heat transfer rate, so that it leads to load limit operation for air cooling unit in summer. In allusion to indirect air cooling radiator with Heller System, high-pressure water jet technique is used and built-in cleaning device is designed to entirely solve above-mentioned problem. Cleaning device works automatically and realizes full cover cleaning. Cleaning-pressure is between 100 and 150bar and cleaning target distance keeps within 200mm. Dust on the surface of radiator can be entirely cleaned. Cleaning flow is 20m3 /h and the cleaning cost decreases greatly. Such device has been successfully tested and worked. Furthermore, it has been applied to the project with a system of 2×600MW supercritical indirect air cooling unit. © (2013) Trans Tech Publications, Switzerland.
Chen Y.,Yanshan University |
Chen Y.,Shenyang Academy of Instrumentation Science Co |
Wang Y.,Yanshan University |
Li H.,North China Institute of Aerospace Engineering |
And 2 more authors.
Yi Qi Yi Biao Xue Bao/Chinese Journal of Scientific Instrument | Year: 2015
This paper focuses on the noise floor of piezoelectric accelerometer, takes the piezoelectric transducer and charge amplifier as study objects, and establishes the mechanical model of piezoelectric transducer single degree of freedom spring-mass-damping mechanical resonance system and the electrical model of piezoelectric element. The Junction Field Effect Transistor (JFET) is taken as the core element to study the main noise source in the circuit, and establish the respective noise model for each source. The construction method of En-In noise model is used to make the inner noise source of the charge amplifier equivalent to the input port; meanwhile, the Y-Δ transformation theory is introduced into the noise analysis of T type bias network. The noise model is used to deduce the noise spectrum density expression of the piezoelectric accelerometer. The experiment data and the theoretical calculation values obtained from the expression were compared, which verifies the effectiveness and correctness of the expression. Using this expression, the key factors affecting the accelerometer noise are analyzed, the low noise design principle of the accelerometer is summarized, which provides a theoretical basis for improving the noise-signal ratio of the accelerometer. ©, 2015, Science Press. All right reserved.
Chen Y.-Q.,Yanshan University |
Chen Y.-Q.,Shenyang Academy of Instrumentation Science Co |
Wang Y.-T.,Yanshan University |
Tang B.-W.,Yanshan University |
And 2 more authors.
Jiliang Xuebao/Acta Metrologica Sinica | Year: 2016
A method of current single-phase fault line selection based on mathematical morphology and generalized S-transform is proposed. Mathematical morphology is a novel nonlinear filtering technique. Considering the signal characteristics of the power system, a linear structural element is selected. Not only can eliminate the burr shape noise, but also maintain the shape of the signal well. Generalized S-transform overcomes the shortcomings of the basic wavelet bases fixed in the S transform, and has a better frequency resolution. The signal was filtered by the mathematical morphological first. Then the generalized S-transform is used to analyze fault signals to get the modulus frequency matrix. Finally the energy characteristics modulus frequency matrix is analyzed to select the fault line. Simulation results show that the method could select fault line accurately under different working conditions of distribution network. © 2016, Acta Metrologica Sinica Press. All right reserved.
Lei P.,Shenyang Academy of Instrumentation Science Co |
Lyu S.-B.,Shenyang Academy of Instrumentation Science Co |
Li Y.,Shenyang Academy of Instrumentation Science Co |
Zhao Y.,Shenyang Academy of Instrumentation Science Co
Faguang Xuebao/Chinese Journal of Luminescence | Year: 2014
Multispectral imaging is an emerging non-destructive detection technology that combines traditional two-dimensional imaging and spectroscopy techniques. In this paper, a multispectral fluorescence imaging system was developed for fast detection of pesticide residues on leaves. It took advantage of fluorescence characteristics of organophosphorus pesticide, combined with multispectral imaging technology and fluorescence excitation technique. Excited by UV-light from 190 to 300 nm, the configured organophosphorus pesticide Omethoate can emit 440 nm fluorescence, and the peak values bear a linear relationship with the concentrations of pesticide.The development of multispectral imaging system with exchangeable filters and experiment results within this article provide the technical support and theoretical basis for the construction of real-time on-line non-destructive detection system of pesticide residues.