http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : LiYun Zhao (검색결과 4 건)
- 무료
- 기관 내 무료
- 유료
-
Novel Water-Air Circulation Quenching Process for AISI 4140 Steel
Liyun Zheng,Dawei Zheng1,Lixin Zhao,Lihui Wang,Kai Zhang 대한금속·재료학회 2013 METALS AND MATERIALS International Vol.19 No.6
AISI 4140 steel is usually used after quenching and tempering. During the heat treatment process in industry production, there are some problems, such as quenching cracks, related to water-cooling and low hardness due to oil quenching. A water-air circulation quenching process can solve the problems of quenching cracks with water and the high cost quenching with oil, which is flammable, unsafe and not enough to obtain the required hardness. The control of the water-cooling and air-cooling time is a key factor in the process. This paper focuses on the quenching temperature, water-air cycle time and cycle index to prevent cracking for AISI 4140 steel. The optimum heat treatment parameters to achieve a good match of the strength and toughness of AISI 4140 steel were obtained by repeated adjustment of the water-air circulation quenching process parameters. The tensile strength, Charpy impact energy at -10 °C and hardness of the heat treated AISI 4140 steel after quenching and tempering were approximately 1098 MPa, 67.5 J and 316 HB, respectively.
-
Liyun Fan,Quan Dong,Chao Chen,Yun Bai,Wensheng Zhao,Xiuzhen Ma 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.10
A numerical model of the combination electronic unit pump (CEUP) fuel injection system was developed in AMESim environment. The effects of five key influencing factors, including cam profile velocity, plunger diameter, length of high pressure fuel pipe, inner diameterof high pressure fuel pipe and nozzle flow rate on injection characteristic parameters, were analyzed by using the developed numericalmodel. On the basis, a correlation analysis between the influencing factors and injection characteristics was performed by usingthe design of experiments (DoE) method, and the influences of these factors were quantized accordingly. Relevant results show that boththe single influencing factor and the interaction among these factors correlates with the injection characteristics, and the correlation representsa complex law with the cam rotational speed. The effect of plunger diameter on the injection pressure, cycle fuel injection quantityand injection duration is the most obvious, especially at a cam rotational speed of 500 r/min and the correlation coefficient is up to 0.82. The length of high-pressure pipe (HP pipe) has the most obvious influence on the coefficient of fuel feeding at cam rotational speed of500 r/min and 800 r/min, and the correlation coefficient is negative. Overall, the independent influence of the factors is more significantthan the combined influence of various factors. The CEUP fuel injection system is a complicated multi-input multi-output (MIMO)nonlinear system in fact.
-
Leader-following Consensus of Second-order Multi-agent Systems With Input Delays
Wei Gao,Yan Ren,LiYun Zhao,Kai Weng,HuiMin Wang 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.9
This paper studies the leader-following consensus of second-order multi-agent systems with input delays. Firstly, a feedback-tracking control protocol with the leader’s delayed state derivative is proposed to guarantee the leader-following consensus. Secondly, considering the same input delay of the second-order multi-agent system, the explicit formula of the upper bound of delay for the asymptotic stability of the second-order multi-agent system is obtained by using the frequency domain analysis method. Compared with the latest existing controllers, the controller designed in this paper improves the convergence speed and tracking accuracy. Thirdly, a variety of diverse input delays are further considered, the feedback tracking controller is designed to improve the convergence speed and tracking accuracy, and sufficient conditions of leader-following consensus are given by using the generalized Nyquist stability criterion. Finally, simulation examples are given to show the effectiveness of our control protocol.
-
The Microstructure and Magnetic Properties of Melt-Spun CeFeB Ribbons with Varying Ce Content
Xuchao Wang,Minggang Zhu,Wei Li,Liyun Zheng,Dongliang Zhao,Xiao Du,An Du 대한금속·재료학회 2015 ELECTRONIC MATERIALS LETTERS Vol.11 No.1
The microstructural and magnetic properties of melt-spun ribbons with thecomposition (CexNd100-x)30FebalCo4Ga0.2B0.92 (where x = 50, 60, 70, 80, and 90)were investigated. The ribbons were examined with Scanning ElectronMicroscopy (SEM), Transmission Electron Microscopy (TEM), and VibratingSample Magnetometry (VSM). It was found that the grain size of the ribbons ison the nanometer scale, and the grain size decreases with decreasing Ce content. The magnetic hysteresis loops showed that the magnetic properties of theribbons gradually deteriorated with increasing Ce content. This is because themagnetic polarization (Js) and magnetocrystalline anisotropy field (HA) ofCe2Fe14B are smaller than those of Nd2Fe14B. Furthermore, from the initialmagnetization curve it was found that increasing the Ce content changes thecoercive force mechanism to the nucleation mechanism. When Ce contentaccounts for 90% of total rare earth metals, the coercive force mechanismmainly appears to be a nucleation mechanism.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
