{"ob_id":65492,"names":[],"terms":[{"ob_id":27799,"label":"long_name","value":"Mg","vocabulary":""},{"ob_id":64470,"label":"units","value":"","vocabulary":""},{"ob_id":66090,"label":"var_id","value":"5","vocabulary":""},{"ob_id":69255,"label":"standard_name","value":"the concentration of total Mg in PM2.5","vocabulary":""}]}