[Water-soluble Inorganic Ion Content of PM and Its Change Characteristics in Urban Area of Beijing in 2022].

To explore the content and variation characteristics of water-soluble ions of atmospheric fine particles (PM) in a Beijing urban area and put forward the pollution prevention and control scheme, the water-soluble ions, gaseous precursors (SO, NO), and meteorological factors (temperature, RH) of PM in 2022 were analyzed and determined. The results showed that the water-soluble ions with the highest proportion in PM in the Beijing City urban area were NO, NH, and SO, accounting for 52.7% of PM.

Spectral phase effects and control requirements of coherent beam combining for ultrashort ultrahigh intensity laser systems.

Based on the premise that further improvements to the size and damage threshold of large-aperture optical components are severely limited, coherent beam combining (CBC) is a promising way to scale up the available peak power of pulses for ultrashort ultrahigh intensity laser systems. Spectral phase effects are important issues and have a significant impact on the performance of CBC. In this work, we analyze systematically factors such as spectral dispersions and longitudinal chromatism, and get the general spectral phase control requirements of CBC for ultrashort ultrahigh intensity laser systems.

Investigation of phase effects of coherent beam combining for large-aperture ultrashort ultrahigh intensity laser systems.

Large-aperture ultrashort ultrahigh intensity laser systems are able to achieve unprecedented super-high peak power. However, output power from a single laser channel is not high enough for some important applications and it is difficult to improve output power from a single laser channel significantly in the near future. Coherent beam combining is a promising method which combines many laser channels to obtain much higher peak power than a single channel.