Dynamics Modelling and Control of a Novel Fuel Metering Valve Actuated by Two Binary-Coded Digital Valve Arrays

A fuel metering valve actuated by two binary-coded digital valve arrays (BDVAs) is proposed to improve the reliability of conventional fuel metering valves piloted by a servo valve. The design concept of this configuration is obtained from the structural characteristics of the dual nozzle-flapper and the flow regulation method of the digital hydraulic technology. The structure and working principle of the fuel metering valve are presented. Then, a mathematical model of the entire valve is developed for dynamic analysis. Subsequently, the mechanism of the transient flow uncertainty of the BDVA is revealed through simulation to determine the fluctuation in the velocity of the fuel metering valve. Furthermore, step response indicates that the delay time of the fuel metering valve is within 4.1 ms. Finally, to improve the position tracking accuracy of the fuel metering valve, a velocity feedforward proportional-integral controller with pulse code modulation is proposed. A series of comparative analyses indicate that compared with those of the velocity feedforward controller, the average and standard deviation of the position error for the proposed controller are reduced by 78 and 72.7%, respectively. The results prove the feasibility of the proposed valve and the effectiveness of the proposed control strategy.

Research and Application of Double-Reheat Boiler in China

The ultra-supercritical (USC) double-reheat technology is an immediate area of research focus in China, since the thermal efficiency of USC double-reheat unit is higher than the USC single-reheat unit. The parameters and capacity of USC double-reheat unit in China have made major breakthroughs, and the thermal efficiency of the units are as high as 47–48%, which is the highest in the world. USC double-reheat boiler is one of the most important devices for USC double-reheat unit, and the design concept and precision have a vital effect on the operation of boiler and power station. The most difficult and important factors in the design of double-reheat boiler are the layout of heating surface and the steam temperature regulation method. Therefore, this work summarizes the arrangement of heating surface and temperature regulation method of existing double-reheat boiler in China. It is hoped that the work will set a benchmark for the development of double-reheat boiler and the future 700 °C power generation unit in the world.

Hand model of the brain training as emotion regulation method for elementary school students

In the era of the COVID-19 pandemic, learning from home comes with positive and negative consequences. The sense of security that children get from distance learning brings negative consequences where children need to adjust to a new paradigm. Problems around learning from home included mental health and emotional problems for students. This psychoeducation aimed to explain the emotion regulation process and how the brain worked in emotion processing. We conducted the program with a pre-survey and interviews with teachers and school principals. Furthermore, online mentoring and surveys to students accompanied by their parents. It is hoped that students could understand their emotions and the basic steps to regulate. The hand model of the brain is the model of the brain in hands to explain concretely the hierarchy and connection between different parts of the brain concerning emotions. This program got a positive response from the participants. Psychoeducation results show an increase in understanding and gave positive feedback that this program is effective and fit to what they needed.

Electric Window Regulator Based on Intelligent Control

In order to effectively solve the problem of installation cost of automobile electric windows and the safety of passengers, the window regulator of the car must have an intelligent control function. For example, most automobile windows now have an anti-pinch function. In this paper, the model of DC brushed motor is analyzed, an intelligent control scheme for automotive power windows is proposed, and the relationship between current ripple and window travel, motor current and external resistance are verified. In the hardware design, S9S12G128 is the main control chip, and the motor current acquisition method is designed. In the software design, intelligent control methods such as current integration method, adaptive and self-learning algorithm and intelligent speed regulation method are proposed to realize functions such as automatic window opening and closing, intelligent anti-pinch and intelligent speed regulation. After many experiments, the results prove the feasibility of the above methods and the stability of the system.

Liquid metal-tailored gluten network for protein-based e-skin

Designing electronic skin (e-skin) with proteins is a critical way to endow e-skin with biocompatibility, but engineering protein structures to achieve controllable mechanical properties and self-healing ability remains a challenge. Here, we develop a hybrid gluten network through the incorporation of an eutectic gallium indium alloy (EGaIn) to design a self-healable e-skin with improved mechanical properties. The intrinsic reversible disulfide bonds/sulfhydryl groups reconfiguration of gluten networks is explored as a driving mechanism to introduce EGaIn as chemical cross-linkers to create hierarchical sulphur bonds, thus inducing the secondary structure rearrangement of gluten to form additional β-sheets as physical cross-linkers. Remarkably, this strategy allows the gluten network to realize a synthetic material-like stretchability (>1600%) and to endure a three-dimensional strain change. The obtained e-skin is biocompatible and biodegradable, and can sense strain changes from different scale human motions. The protein network micro-regulation method paves the way for future skin-like protein-based e-skin.