Study on the wear and corrosion resistance of Ni-P-SiC composite coating on AZ91D alloyXue, Yan; Wang, Zhenguo
doi: 10.1117/12.2667398pmid: N/A
The wear and corrosion resistance of Ni-P-SiC composite coating on AZ91D alloy were investigated in this paper. The surface morphology, microhardness, wear, and corrosion resistance of Ni-P-SiC composite coating under different deposition times were carried out by SEM, digital microhardness tester, and corrosion and wear tests. When the deposition time is 120 min, the microhardness of 641Hv is the highest, and Ni-P-SiC composite coating has better corrosion and excellent wear resistance, the values of Ecorr, Icorr, and wear volume are -0.73 V, 0.78 µAꞏcm2, and 1.04×10−3 mm3 , respectively. The properties of Ni-P-SiC composite coating are influenced by the deposition time. Ni-P-SiC composite coating deposited for 120 min has higher micro-hardness, better corrosion, and wear resistance.
Direct determination of thermodynamic temperature by an optical method based on atomic absorption spectroscopyLi, Xiaokuan; Li, Yudong; Liu, Yali; Feng, Liangsen; Li, Wei; Li, Xinliang
doi: 10.1117/12.2667538pmid: N/A
Doppler broadening thermometry (DBT) takes advantage of the high resolution characteristic of laser absorption spectroscopy to obtain thermodynamic temperature by measuring optical frequency. It is one of the research hotspots in the field of thermodynamic temperature measurement after the Kelvin redefinition in 2018. In this paper, the direct absorption spectroscopy based on Cesium (133Cs) D1 (6S1/2→6P1/2) line was measured, and the thermodynamic temperature of atomic gas in thermal equilibrium state was obtained by extracting Doppler width of absorption line. The experimental results showed that average relative error of thermodynamic temperature was 0.01% and the standard deviation was 0.14% after 50 rounds of testing at 303.15 K. These research results prove the feasibility of Doppler broadening temperature measurement, and provide research support for the realization and transfer of thermodynamic temperature.
LED spectral optimization based on intermediate visionWang, Yue; Zhao, Shan; Wang, Linyuan; Ju, Jiaqi; Yao, Peijun
doi: 10.1117/12.2667406pmid: N/A
High luminous efficiency and good colour rendering are the goals of white light spectral optimisation, improving the quality of light and creating a comfortable light environment is the direction of research. The goal of the work is to establish a multi-channel spectral optimization technique for light emitting diodes (LEDs) based on visual advantages. Using actual LED parameters as input, the traditional colour rendering index (Ra) and a stricter colour tolerance was used as constraints in the visual evaluation. Specifically, Ra>90, luminous efficacy of radiation (LER)>300, color tolerance less than five SDCM. Those that satisfy all three conditions at the same time are used as the solution set for intermediate vision evaluation. The results of the study show that at least four channels are used to satisfy the constraints. Additionally, we examined the relationship between S/P values and color temperature (CCT) when using intermediate vision, and the findings indicate that LED light sources with higher color temperatures are better suited for these situations.
A hybrid deep neural network for short-time wind power predictionHao, Yuchen; Li, Xiao; Huo, Xuesong; Chai, Yun; Yan, Quanchun; Peng, Cheng
doi: 10.1117/12.2667257pmid: N/A
The accurate prediction of wind power is related to the accuracy of power generation plan and overall scheduling, and wind power is a clean energy with randomness, intermittence and volatility. Therefore, we propose a novel short-term wind power prediction method based on hybrid deep neural network. This method does not require meteorological data and only uses a two-stream framework. The spatial features were extracted by using one-dimensional convolutional network, the long short-term memory network (LSTM) was used to extract temporal features, and then fuses the two parts of features for prediction. Through the analysis of three years' data of a wind farm in east China, we prove the validity and practicability of the prediction model, which provides strong support for the reliability analysis of power prediction.
Study on spray drying process of Sm2Zr2O7 slurry for thermal sprayingHao, Hongrui; Li, Yang; Zhang, Qingmeng; Song, Xiaoyun
doi: 10.1117/12.2668252pmid: N/A
A new type of Sm2Zr2O7 ceramic material has become a candidate material for thermal barrier coating because of its low thermal conductivity, high thermal expansion coefficient and good high temperature structure stability. In this paper, the effects of different process parameters on the morphology of ceramic powders were investigated. The spray drying technology was used to prepare Sm2Zr2O7 agglomerated powder. The micro morphology of Sm2Zr2O7 powder after granulation was observed by SEM. The effects of inlet temperature, pump creep rate on the characteristics of agglomerated powder were analyzed. At the same time, the effects of slurry properties on the micro characteristics of powder after granulation were discussed. The optimized Sm2Zr2O7 spray granulation process was determined as inlet temperature 175 ℃, pump creep rate 30% .
The effects of laser parameters on the excitation of laser-generated surface acoustic waves in the Q345 steelLi, Ziming
doi: 10.1117/12.2667707pmid: N/A
Nondestructive testing plays an important role in modern cities. Laser-generated surface acoustic waves (SAWs) are widely used in the nondestructive testing of structures due to their advantages, such as being non-contact and having a wide frequency bandwidth, long distance propagation, little attenuation, and so on. Q345 steel is currently used in many areas, especially in large structures. In order to utilize laser-generated SAWs more reasonably, this paper discusses the effects of laser parameters on the excitation of SAWs in Q345 steel with the numerical method. The three parameters of the pulse energy, rise time, and pulse width are discussed separately. The results show that the amplitude of displacement is directly proportional to the pulse energy and inversely proportional to the rise time and pulse width. These proposed results can provide a guideline for the choice of the excitation parameters in the laser-generated SAWs nondestructive evaluation on Q345 steel.
Research on ancillary service products in power markets with high renewable penetration: a review on international ancillary service design progress and recommendations for ChinaZhao, Yue; Liu, Sijie; Bai, Yang; Cai, Qiuna; Shi, Anqi; Meng, Xinyu; Chen, Yuguo
doi: 10.1117/12.2669340pmid: N/A
With the increasement of uncertainty and decrement of grid inertia caused by renewable energy generation, the ramping capacity, fast frequency response and inertia resources are crucial to ensure the safe operation of the grid. New types of anxillary services need to be gradually incorporated into the power market system to reflect value of system flexibility and reliabiltiy resources. This paper reviewed ancillary service product development for high renewable-penetrated grid among international power market design. The integration approaches of these ancillary products with the existing energy market is analyzed. Recommendations on the implementation of these products in China are made based on the generation mix and the market readiness across different provinces. With these ancillary products, the power market will be transformed to facilitate higher renewable generation and ensure safe and flexible operations.
The preparation of silicon carbide and its corresponding properties for electronic packaging applicationsZhang, Xiaoli; Zhang, Xiaoyi; Wang, Zhuo; Mi, Liwei; Fan, Wenjie
doi: 10.1117/12.2667282pmid: N/A
Traditional packaging materials are suffering from poor high-temperature-using, however, the SiC own ideal coefficient of thermal expansion (CTE) and thermal conductivity (TC), and at the same time, it can be used in high temperatures meeting the requirement of the advanced electronic packaging. But traditionally, SiC is made at a high temperature and with a complex producing process. Some researchers are focused on SiC with some Al additions, but we know that Al will volatilize when the samples are heated over than melt-point, so this method would also strict its applications. Other works had been taken on diamond addition to realize packaging function, but this method needed a high-temperature infiltration process too. In fact, the non-method above was economic or convenient to manufacture in nowadays industry practice. Fortunately, a new way to gain dense SiC at a very low temperature in an open environment had been gotten by our group.
Study on effectiveness evaluation of ice melting and snow melting of high elastic salt storage asphalt pavementLv, Hongli; Ma, Rong; Guo, Rui; Wang, Zhennan; Xia, Zhenning
doi: 10.1117/12.2667881pmid: N/A
High elasticity salt storage class ice melting snow pavement is in high elasticity class material stress deicing and salt storage class material by reducing the freezing point deicing snow technology principle based on the effective deicing snow function, in the road paving completion of the initial deicing snow effect is more significant, but its deicing snow performance of the validation study is still relatively small. As long as the function timeliness of high elastic salt storage snow melting pavement is determined by the salt content and precipitation rate in salt storage materials. Therefore, this paper accelerates the simulation of salt precipitation through sodium chloride dissolution test, analyzes the influence of various influencing factors on the salt analysis state with conductivity as the index, and obtains the prediction equation of ice melting snow thawing timeliness, and takes Puyang city as an example to make prediction of its service life.