A Review of Key Technologies for High-Speed Motorized Spindles of CNC Machine Tools

The high-speed and high-precision motorized spindle is the future development trend of the CNC machine tool field, and has become the focus of research in the world. High-speed motorized spindles tend to develop in the direction of high precision, high speed, low energy consumption, high efficiency, and high reliability. We undertake a through, systematic review of the development history perspective of the research on precision bearing technology, dynamic balancing technology, thermal error measurement and compensation technology with regard to the key technologies of high-speed motorized spindles. On this basis, the current level of development of key technologies for high-speed motorized spindles is analyzed, and the objective advantages and disadvantages of existing technologies are summarized. Finally, the development tendency of high-speed motorized spindle technology is predicted and foreseen

Phloroglucinol Derivatives with Protein Tyrosine Phosphatase 1B Inhibitory Activities from Eugenia jambolana Seeds

Fifteen new phloroglucinol derivatives, jamunones A-O (1-8 and 10-16, respectively), along with one known analogue spiralisone C (9), were isolated from Eugenia jambolana seeds. Their structures were elucidated by detailed nuclear magnetic resonance and mass spectrometry spectroscopic data interpretation. Compounds 1-9, 11, 12, and 14-16 inhibited protein tyrosine phosphatase 1B activity with IC50 values ranging from 0.42 to 3.2 μM

Phloroglucinol Derivatives with Protein Tyrosine Phosphatase 1B Inhibitory Activities from <i>Eugenia jambolana</i> Seeds

Fifteen new phloroglucinol derivatives, jamunones A–O (<b>1–8</b> and <b>10–16</b>, respectively), along with one known analogue spiralisone C (<b>9</b>), were isolated from <i>Eugenia jambolana</i> seeds. Their structures were elucidated by detailed nuclear magnetic resonance and mass spectrometry spectroscopic data interpretation. Compounds <b>1–9</b>, <b>11</b>, <b>12</b>, and <b>14–16</b> inhibited protein tyrosine phosphatase 1B activity with IC₅₀ values ranging from 0.42 to 3.2 μM