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The paper presents the investigations of a unique jet as selfresonating water jet including the modulating principles, characteristics of impact pressure and rock erosion, and field applications in petroleum engineering in China. The research showed that jet nozzles designed with organ pipe structure could generate significant self-resonating cavitating water jets. As compared with conventional cone-shaped nozzle with 120 taper angle, the amplitudes of pressure fluctuation and maximum impact pressure of selfresonating cavitating water jets increase by 24 and 37%, respectively, and rock erosion efficiency increases by 1 to 2 times. Self-resonating water jets have been successfully applied in petroleum drilling engineering, with enhanced average rates of penetration of tricone bits by 31.2% and improved bit footages by 29.1%. Treatment of near wellbore formation and self-excited oscillating water injection with self-resonating water jets have resulted in economic efficiency.

Pre-plastic deformation (PPD) treatments on bulk metallic glasses (BMGs) have previously been shown to be helpful in producing multiple shear bands. In this work, the applicability of the PPD approach on BMGs with different Poisson’s ratios was validated based on experimental and simulation observations. It was found that for BMGs with high Poisson’s ratios (HBMGs, e.g., Zr56Co28Al16 and Zr46Cu46Al8), the PPD treatment can easily trigger a pair of large plastic deformation zones consisting of multiple shear bands. These PPD-treated HBMGs clearly display improved strength and compressive plasticity. On the other hand, the mechanical properties of BMGs with low Poisson’s ratios (LBMG, e.g., Fe48Cr15Mo14Y2C15B6) become worse due to a few shear bands and micro-cracks in extremely small plastic deformation zones. Additionally, for the PPD-treated HBMGs with similar high Poisson’s ratios, the Zr56Co28Al16 BMG exhibits much larger plasticity than the Zr46Cu46Al8 BMG. This phenomenon is mainly due to more defective icosahedral clusters in the Zr56Co28Al16 BMG, which can serve as nucleation sites for shear transformation zones (STZs) during subsequent deformation. The present study may provide a basis for understanding the plastic deformation mechanism of BMGs.