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The present study provided strong evidence that suicide ideation and attempts were serious problems among adolescents in China, to which peer relationships played an important role. Further, feeling of loneliness acted as a moderator affecting the association between peer relationships and suicide ideation and attempts. Finally, there were some gender differences that have important implications.

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Robust high-power narrow-linewidth lasers at 589 nm are required for sodium laser guide star adaptive optics in astronomy. A high-power 589 nm laser based on Raman fiber amplifier is reported here, which works in both continuous-wave and pulsed formats. In the continuous-wave case, the laser produces more than 50 W output. In the pulsed case, the same laser produces square-shaped pulses with tunable repetition rate (500 Hz to 10 kHz) and duration (1 ms to 30 μs). The peak power is as high as 84 W and remains constant during the tuning. The laser also emits an adjustable sideband at 1.71 GHz away from the main laser frequency for better sodium excitation. The versatility of the laser offers much flexibility in laser guide star application.