text: const mongoose = require('mongoose')
  
  const schema = new mongoose.Schema({
    title: { type: String },
    category: { type: String },
    time: { type: Date },
    display_time: { type: String },
    leadAuther: { type: String },
    laUnit: { type: String },
    corresAuther: { type: String },
    caUnit: { type: String },
    auther: { type: String },
    level: { type: String },
    keyword: { type: String },
    journal: { type: String },
    issn: { type: String },
    url: { type: String }
  })
  
  module.exports = mongoose.model('Paper', schema)