The Chinese Hα Solar Explorer(CHASE) mission: An overview

The Chinese Hα Solar Explorer(CHASE), dubbed “Xihe”—Goddess of the Sun, was launched on October 14, 2021 as the first solar space mission of China National Space Administration(CNSA). The CHASE mission is designed to test a newly developed satellite platform and to acquire the spectroscopic observations in the Hα waveband. The Hα Imaging Spectrograph(HIS)is the scientific payload of the CHASE satellite. It consists of two observational modes: raster scanning mode and continuum imaging mode. The raster scanning mode obtains full-Sun or region-of-interest spectral images from 6559.7 to 6565.9 ? and from 6567.8 to 6570.6 ? with 0.024 ? pixel spectral resolution and 1 min temporal resolution. The continuum imaging mode obtains photospheric images in continuum around 6689 ? with the full width at half maximum of 13.4 ?. The CHASE mission will advance our understanding of the dynamics of solar activity in the photosphere and chromosphere. In this paper, we present an overview of the CHASE mission including the scientific objectives, HIS instrument overview, data calibration flow, and first results of on-orbit observations.

Diverse molecular compositions of dissolved organic matter derived from different composts using ESI FT-ICR MS

Dissolved organic matter(DOM)derived from various composts can promote significant changes of soil properties.However,little is known about the DOM compositions and their similarities and differences at the molecular level.In this study,the molecular compositions of DOM derived from kitchen waste compost(KWC),green waste compost(GWC),manure waste compost(MWC),and sewage sludge compost(SSC)were characterized by electrospray ionization coupled with Fourier transform ion cyclotron resonance mass spectrometry(ESI FT-ICR MS).The molecular formulas were classified into four subcategories:CHO,CHON,CHOS,and CHONS.The KWC,MWC,and SSC DOM represented the highest fraction(35.8%-47.4%)of CHON subcategory,while the GWC DOM represented the highest fraction(68.4%)of CHO subcategory.The GWC DOM was recognized as the nitrogen-and sulfurdeficient compounds that were less saturated,more aromatic,and more oxidized compared with other samples.Further analysis of the oxygen,nitrogen-containing(N-containing),and sulfur-containing(S-containing)functional groups in the four subcategories revealed higher organic molecular complexity.Comparison of the similarities and differences of the four samples revealed 22.8%ubiquitous formulas and 17.4%,11.1%,10.7%,and 6.3%unique formulas of GWC,KWC,SSC,and MWC DOM,respectively,suggesting a large proportion of ubiquitous DOM as well as unique,source-specific molecular signatures.The findings presented herein provide new insight into the molecular characterization of DOM derived from various composts and demonstrated the potential role of these different compounds for agricultural utilization.