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32 results on '"Yang, Zhida"'

6. Can CINRAD Radar With VCP-21 Mode Capture the Accumulated Rainfall Pattern and Intensity of Fast-Moving Storms?

Author

Yang, Zhida, Qi, Youcun, Zhang, Zhe, and Li, Donghuan

Abstract

China New Generation Weather Radar (CINRAD) operated in volume coverage pattern 21 (VCP21) mode may miss important information about precipitation for storms that evolve rapidly and move fast due to its volume scanning interval (about 6 min). However, despite the rapid changes and fast movement of storms, according to the continuity equation, the pattern and location of storms are continuous in temporal and spatial. An attempt is made in this research to use interpolation to supplement the missing information about storm evolution and improve the radar quantitative precipitation estimation (QPE) quality. Three interpolation methods are used to supplement storm evolution information between scan intervals for two fast-moving storm events. In these events, weather radar using VCP-21 mode cannot capture storm evolution well. The results show that all of the three interpolation methods do enhance the accuracy of the radar QPE. However, the linear interpolation method only describes the linear variation of storms, and the optical flow method can consider the movement of the storm and has a significant improvement in capturing the rainfall area, yet it cannot delineate the variation in rainfall shape and intensity. The Bi-directional optical flow (BIO) can describe not only the storm movement, but also the change of intensity and pattern of storms. BIO can greatly enhance the accuracy of radar QPE among the three methods. This study suggests that the interpolation of fast-moving storms between two neighboring radar volume scans needs to take into account both intensity variation and precipitation movement. The application of the BIO method can significantly improve the accuracy of radar QPE, namely the rainfall intensity and pattern.

Published
2024
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10. Active control of amplitude and phase of high-power RF systems in EAST ICRF heating experiments

Author

Zhu, Guanghui, primary, Liu, Lunan, additional, Mao, Yuzhou, additional, Zhang, Xinjun, additional, Guo, Yaoyao, additional, Ai, Lin, additional, Jiang, Runhao, additional, Qin, Chengming, additional, Zhang, Wei, additional, Yang, Hua, additional, Yuan, Shuai, additional, Wang, Lei, additional, Ju, Songqing, additional, Wang, Yongsheng, additional, Sun, Xuan, additional, Yang, Zhida, additional, Wang, Jinxin, additional, Cheng, Yan, additional, Li, Hang, additional, and Luo, Jingting, additional

Published
2022
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12. An axisymmetric mirror device for studying confinement and instability.

Author

Yang, Zhida, Xu, Zelin, Zhu, Guanghui, Ren, BaoMing, and Sun, Xuan

Subjects
*MAGNETIC flux density, *PLASMA devices, *STELLARATORS, *PLASMA confinement, *MAGNETIC devices, *MODULATIONAL instability, *BOLOMETERS, *MIRRORS, *MAGNETIC fields
Abstract

We describe a magnetic mirror device, namely, the Keda Mirror with AXisymmetricity (KMAX), which aims to study new approaches to confine and stabilize the mirror plasma as well as basic plasma research. KMAX consists of one central cell, two side cells, and two end chambers at two ends of the device. For the central cell, the mirror-to-mirror distance is 5.2 m, while the central cylinder is 2.5 m in length and 1.2 m in diameter. The plasmas are generated by two washer guns located in the end chambers, which subsequently flow into the central cell and merge there. The density in the central cell is usually adjusted by changing the magnetic field strength inside the side cell, and it ranges from 1017 to 1019 m−3, depending on the experimental requirement. Ion cyclotron frequency heating with two 100 kW transmitters is routinely used to heat up the ions. Plasma controls mainly rely on configuring the magnetic geometry and rotating magnetic fields to improve the confinement and suppress instability. Routine diagnostics, such as probes, interferometers, spectrometers, diamagnetic loops, and bolometers, are also reported in this paper. [ABSTRACT FROM AUTHOR]

Published
2023
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20. Simulation research on passive safety injection system of marine nuclear power plant based on compressed gas

Author

Zhou Longyu, Zhou Jie, Yang Zhida, Wang Junling, and Luan Xiuchun

Subjects
Booster pump, 020209 energy, Nuclear engineering, Active safety, 02 engineering and technology, AC power, 01 natural sciences, 010305 fluids & plasmas, law.invention, Injection pump, Accumulator (energy), Pressure head, Nuclear Energy and Engineering, law, Storage tank, 0103 physical sciences, Nuclear power plant, 0202 electrical engineering, electronic engineering, information engineering, Environmental science
Abstract

In case of a large or medium LOCA accident of marine nuclear power plant, the loop pressure drops rapidly. In case of power failure of the whole ship at this time, the active safety injection system will lose its function because the safety injection pump needs AC power, and the core is at risk of melting. A passive marine safety injection system based on high-pressure compressed gas is designed for the superposition of large and medium LOCA accidents and the whole ship's power failure accidents, including the safety injection subsystem of medium and low pressure and the safety injection subsystem of recirculation. The energy required for safety injection is provided by the potential energy of compressed gas, the pressure head is provided by the technology of gas-liquid booster pump, and the collection signals and valves are controlled by the technology of intelligent fluid control unit with small power consumption. The power supply used in the system is provided by DC 24 V battery. The mathematical and physical models of accumulator, gas storage tank, gas-liquid booster pump, reactor body and its pipeline are established for the designed passive safety injection system. The operation and safety characteristics of medium pressure safety injection, low pressure safety injection and recycling safety injection under LOCA accident conditions are simulated. The safety injection time and flow rate of three safety injection pressures are simulated by medium pressure safety injection, the safety injection time and peak temperature are simulated by low pressure safety injection, and the pressure and system temperature are simulated by recirculation safety injection. The simulation results show that the marine passive safety injection system designed under LOCA accident conditions can meet the requirements of core cooling.

Published
2020

25. Shifting control system design for hydraulic mechanical transmission of wet clutch

Author

Yang Zhida, Wang Liyong, and Chen Tao

Subjects
law, Computer science, Control system, Control (management), Clutch, Hydraulic machinery, Communications protocol, Signal, Remote control, Automotive engineering, law.invention, CAN bus
Abstract

This paper introduces a control system of wet clutch hydraulic mechanical gearbox. The system is based on the CAN bus communication protocol to write the control signal of the shift signal. It is designed 6 forward gear and 1 reverse gear stalls for the gearbox to control. The local / remote switch is achieved in hydraulic mechanical gearbox. The actual operation results of the shift control system show that the system is stable, reliable and accurate in parameter measurement. The feasibility of the local / remote control method is verified, and the control system has practical application value.

Published
2017

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