{"ob_id":65476,"names":[],"terms":[{"ob_id":27814,"label":"long_name","value":"Ca","vocabulary":""},{"ob_id":34176,"label":"var_id","value":"12","vocabulary":""},{"ob_id":64470,"label":"units","value":"","vocabulary":""},{"ob_id":69235,"label":"standard_name","value":"the concentration of total Ca in PM2.5","vocabulary":""}]}