The intermediate link compression characteristics of e-commerce express logistics ne tworks influence the tradition al mode of circulation of goods and economic organization,and alter the city spatial pattern.Based on...The intermediate link compression characteristics of e-commerce express logistics ne tworks influence the tradition al mode of circulation of goods and economic organization,and alter the city spatial pattern.Based on the theory of space of flows,this study adopts China Smart Logistics Network relational data to build China's e-commerce express logistics network and explore its spatial structure characteristics through social network analysis(SNA),the PageRank technique,and geospatial methods.The results are as follows:the network density is 0.9270,which is close to 1;hence,indicating that e-commerce express logistics lines between Chinese cities are nearly complete and they form a typical network structure,thereby eliminating fragmented spaces.Moreover,the average minimum number of edges is 1.1375,which indicates that the network has a small world effect and thus has a high flow efficiency of logistics elements.A significant hierarchical diffusion effect was observed in dominant flows with the highest edge weights.A diamond-structured network was formed with Shanghai,Guangzhou,Chongqing,and Beijing as the four core nodes.Other node cities with a large logistics scale and importance in the network are mainly located in the 19 city agglomerations of China,revealing the fact that the development of city agglomerations is essential for promoting the separation of experience space and changing the urban spatial pattern.This study enriches the theory of urban networks,reveals the flow laws of modern logistics elements,and encourages coordinated development of urban logistics.展开更多
为探究烟草种子萌发过程对低温胁迫的响应,对萌发1 d、2 d和3 d的种子分别进行2 d低温处理(LT1、LT2和LT3),分析不同萌发时期种子遇到低温的蛋白与多肽变化,分别以萌发2 d、3 d和4 d的种子为对照(GS2、GS3和GS4),形成3个组合GS2 vs LT1...为探究烟草种子萌发过程对低温胁迫的响应,对萌发1 d、2 d和3 d的种子分别进行2 d低温处理(LT1、LT2和LT3),分析不同萌发时期种子遇到低温的蛋白与多肽变化,分别以萌发2 d、3 d和4 d的种子为对照(GS2、GS3和GS4),形成3个组合GS2 vs LT1、GS3 vs LT2和GS4 vs LT3。结果显示,GS2 vs LT1、GS3 vs LT2和GS4 vs LT3的差异多肽集合的交集共计20个多肽,GO和KEGG富集分析发现3个组合的差异蛋白均与碳代谢、氨基酸生物合成相关;此外鉴定到8个参与到低温应答的多肽,其中Nitab4.5_0002257g0090多肽在3个组合中同时被鉴定到,可能在低温应答过程中存在重要的功能。本研究为后续挖掘多肽在低温应答过程的功能提供了研究基础。展开更多
基金Under the auspices of National Natural Science Foundation of China(No.42071165,41801144)GDAS’Project of Science and Technology Development(No.2023GDASZH-2023010101,2021GDASYL-20210103004)。
文摘The intermediate link compression characteristics of e-commerce express logistics ne tworks influence the tradition al mode of circulation of goods and economic organization,and alter the city spatial pattern.Based on the theory of space of flows,this study adopts China Smart Logistics Network relational data to build China's e-commerce express logistics network and explore its spatial structure characteristics through social network analysis(SNA),the PageRank technique,and geospatial methods.The results are as follows:the network density is 0.9270,which is close to 1;hence,indicating that e-commerce express logistics lines between Chinese cities are nearly complete and they form a typical network structure,thereby eliminating fragmented spaces.Moreover,the average minimum number of edges is 1.1375,which indicates that the network has a small world effect and thus has a high flow efficiency of logistics elements.A significant hierarchical diffusion effect was observed in dominant flows with the highest edge weights.A diamond-structured network was formed with Shanghai,Guangzhou,Chongqing,and Beijing as the four core nodes.Other node cities with a large logistics scale and importance in the network are mainly located in the 19 city agglomerations of China,revealing the fact that the development of city agglomerations is essential for promoting the separation of experience space and changing the urban spatial pattern.This study enriches the theory of urban networks,reveals the flow laws of modern logistics elements,and encourages coordinated development of urban logistics.
文摘为探究烟草种子萌发过程对低温胁迫的响应,对萌发1 d、2 d和3 d的种子分别进行2 d低温处理(LT1、LT2和LT3),分析不同萌发时期种子遇到低温的蛋白与多肽变化,分别以萌发2 d、3 d和4 d的种子为对照(GS2、GS3和GS4),形成3个组合GS2 vs LT1、GS3 vs LT2和GS4 vs LT3。结果显示,GS2 vs LT1、GS3 vs LT2和GS4 vs LT3的差异多肽集合的交集共计20个多肽,GO和KEGG富集分析发现3个组合的差异蛋白均与碳代谢、氨基酸生物合成相关;此外鉴定到8个参与到低温应答的多肽,其中Nitab4.5_0002257g0090多肽在3个组合中同时被鉴定到,可能在低温应答过程中存在重要的功能。本研究为后续挖掘多肽在低温应答过程的功能提供了研究基础。
