Research on Key Quality Characteristics of Electromechanical Product Based on Meta-Action Unit

Electromechanical products have many quality characteristics, representing their quality. In addition, there are long-existed quality problems of electromechanical products, such as poor accuracy, short precision life, large fluctuations in performance, frequently failing, and so on. Based on meta-action unit (MU) for electromechanical products, this book chapter proposes a key quality characteristic control method, which provides theoretical and technical support for essentially guaranteeing the complete machine’s quality. The formation mechanisms of MU’s four key quality characteristics (precision, precision life, performance stability, and reliability) are studied. Moreover, we introduce an overview of key quality characteristic control methods based on MU. The complex large system research method of “decomposition-analysis-synthesis” is adopted to study these key science problems

Interlayer magnetic interactions and ferroelectricity in π\pi/3-twisted CrX2_2 (X = Se, Te) bilayers

Recently, two-dimensional (2D) bilayer magnetic systems have been widely studied. Their interlayer magnetic interactions play a vital role in the magnetic properties. In this paper, we theoretically studied the interlayer magnetic interactions, magnetic states and ferroelectricity of $\pi$/3-twisted CrX$_2$ (X = Se, Te) bilayers ($\pi$/3-CrX$_2$). Our study reveals that the lateral shift could switch the magnetic state of the $\pi$/3-CrSe$_2$ between interlayer ferromagnetic and antiferromagnetic, while just tuning the strength of the interlayer antiferromagnetic interactions in $\pi$/3-CrTe$_2$. Furthermore, the lateral shift can alter the off-plane electric polarization in both $\pi$/3-CrSe$_2$ and $\pi$/3-CrTe$_2$. These results show that stacking is an effective way to tune both the magnetic and ferroelectric properties of 1T-CrX$_2$ bilayers, making the 1T-CrX$_2$ bilayers hold promise for 2D spintronic devices