ass日本风韵熟妇pics男人扒开女人屁屁桶到爽|扒开胸露出奶头亲吻视频|邻居少妇的诱惑|人人妻在线播放|日日摸夜夜摸狠狠摸婷婷|制服 丝袜 人妻|激情熟妇中文字幕|看黄色欧美特一级|日本av人妻系列|高潮对白av,丰满岳妇乱熟妇之荡,日本丰满熟妇乱又伦,日韩欧美一区二区三区在线

Quality-related data collecting by the Internet of things sensing device was added to the blockchain, which could solve the problem of data being easily tampered and increase the data credibility in the storage link. However, data stored directly in the blockchain can result in low system throughput and long response time. The dual storage design of “database + blockchain” can greatly improve the response speed, but its response speed still cannot meet the demand. Aiming to improve the dual-storage design of “database + blockchain” by using the method of data Hash value secondary chain and verification based on the characteristics of fruit and vegetable quality traceability. The time complexity of the improved method was reduced from linear order to constant order in terms of data query. The results showed that the efficiency of the improved method was greatly enhanced. The average query time was 0.066s. And the query time could remain constant as the increase of data items, which solved the problem of low query efficiency for the application of blockchain technology in the fruit and vegetable quality traceability system. According to Hyperledger Fabric platform, the improved method was used to realize the development of fruit and vegetable quality traceability system, which achieved good demonstration effect when it was applied to fruit and vegetable enterprises.