Recently, we reported a series of reversibly interlocked polymer networks(RILNs), whose mechanical robustness and functionalities improvement was believed to be derived from topological interlocking of two sub-network...Recently, we reported a series of reversibly interlocked polymer networks(RILNs), whose mechanical robustness and functionalities improvement was believed to be derived from topological interlocking of two sub-networks, although the direct evidence for the deduction is still lacking. Herein, a specially-designed RILNs system, in which the inter-component hydrogen bonds can be shielded as needed, was prepared and used to study the micro-structures of RILNs, aiming to verify the existence of mechanical interlocking in RILNs. By changing the pH of the swelling solvent, the effect exerted by the inter-component non-covalent bonds was eliminated, so detailed information of the networks structure was exposed. The small angle X-ray scattering(SAXS) and small-angle neutron scattering(SANS) results indicated that swelling-induced structural evolution of the two sub-networks mutually affected each other, even when the inter-component hydrogen bonds were absent, proving the presence of topological interlocking. The findings may help to draw a more accurate physical image and reveal the detailed structureproperty relationship of RILNs.展开更多
Recently, literature on urban network research from the perspective of ?rm networks has been increasing. This research mainly used data from the headquarters and branches of all 2581 listed manufacturing companies in ...Recently, literature on urban network research from the perspective of ?rm networks has been increasing. This research mainly used data from the headquarters and branches of all 2581 listed manufacturing companies in the Yangtze River Delta from 1990 to 2017, and studied the urban network through an interlocking network model that quantifies the links between enterprises. The results showed that the spatial distribution of listed manufacturing industries in the Yangtze River Delta was relatively concentrated, and cities such as Shanghai, Nanjing, and Hangzhou were hot spots for the spatial distribution of listed manufacturing industries. However, Fuyang, Suqian, Chizhou, Lishui and other network edge cities were less distributed in manufacturing. The urban network of the Yangtze River Delta has significant hierarchical characteristics. The urban network of the Yangtze River Delta presents a multi-center network development mode with Shanghai as the center and Nanjing, Hangzhou, and Hefei as the sub-centers. Moreover, we found that the development of inter-city connections in the Yangtze River Delta was driven by network mechanisms of priority attachment and path dependence. The radiating capacity and agglomeration capacity of cities in the Yangtze River Delta have a strong polarization characteristic. The core cities such as Shanghai, Nanjing, Hangzhou, and Hefei have much higher network radiation capabilities than network aggregation capabilities. However, other non-core cities and network edge cities have weak network radiation capabilities, and mainly accept network radiation from core cities. It enriches the research of urban networks based on real inter-?rm connections, and provides ideas for the wider regional study and the combination of econometric techniques and social network analysis.展开更多
深入分析连锁董事网络演化动因及其作用机制对理解企业各种经营行为具有关键意义.基于社会网络分析方法,结合指数随机图模型(Exponential Random Graph Model,ERGM)和系统动力学(System Dynamics,SD)模型,对2010—2019年中国沪深A股上...深入分析连锁董事网络演化动因及其作用机制对理解企业各种经营行为具有关键意义.基于社会网络分析方法,结合指数随机图模型(Exponential Random Graph Model,ERGM)和系统动力学(System Dynamics,SD)模型,对2010—2019年中国沪深A股上市企业连锁董事网络结构的演化特征、驱动因素及形成机制展开分析.研究结果表明:(1)我国连锁董事网络呈现持续扩张的趋势,具有高度社群化和小世界特性,网络结构具备一定韧性,在遭遇冲击后更倾向于建立轻量级联结;(2)通过对ERGM的分析发现,网络结构稳定并持续演化,监事会规模、两权分离率、地理距离与产权性质对网络形成及演化影响显著;(3)SD仿真结果显示,市场化进程和外部冲击促使企业增加董事联结以获取竞争优势和资源支持,中心度受企业间董事联结数量、多维邻近性及其滞后作用的多重影响,路径长度和外部冲击显著影响社区数量与聚类集群;外部冲击下,企业间董事联结数量、社区数量与聚类集群变化明显,而股权制衡度和两权分离率相对稳定.本研究解析的连锁董事网络的演化因素与形成机制对理解和解释企业行为提供了新视角和思路.展开更多
研究基于DCS(Distributed Control System)的燃气-蒸汽联合循环机组运行智能控制系统,确保机组安全运行的同时,提高机组整体运行效率。构建基于DCS的燃气-蒸汽联合循环机组运行智能控制框架,过程控制层的Mark VI系统、DCS系统根据监测...研究基于DCS(Distributed Control System)的燃气-蒸汽联合循环机组运行智能控制系统,确保机组安全运行的同时,提高机组整体运行效率。构建基于DCS的燃气-蒸汽联合循环机组运行智能控制框架,过程控制层的Mark VI系统、DCS系统根据监测数据变化实现机组设备、旁路等自动控制。SIS层接收联合循环机组监测数据后,将其作为基于深度神经网络故障诊断模型的输入,实现机组设备故障的识别。在检测到故障时触发联锁保护子系统动作,将停机指令下达给自动启停控制子系统,使机组停止运行。实验结果表明,该系统可实现燃气-蒸汽联合循环机组设备故障识别,在100次训练后,训练损失为0.1左右,F-Score指标最大值为0.93;故障工况下,该系统可根据预定逻辑实现燃气-蒸汽联合循环机组自动停机。展开更多
Mechanically interlocked networks(MINs)provide a versatile platform for engineering materials that combine mechanical strength with dynamic adaptability.Their performance hinges on the constrained intramolecular motio...Mechanically interlocked networks(MINs)provide a versatile platform for engineering materials that combine mechanical strength with dynamic adaptability.Their performance hinges on the constrained intramolecular motion of mechanical bonds,so the deliberate selection of capping groups is essential for tailoring properties.Herein,we develop an innovative capping strategy for mechanical bonds by employing graphene oxide(GO)as the capping unit,enabling the construction of a new class of mechanically interlocked networks(GOMINs)with enhanced mechanical performance.GOMINs benefit both from the reinforcing effect of GO as a nanofiller and its innovative use as a capping unit that creates continuous mechanical bonds,collectively improving their mechanical strength and adaptability.Compared to the non-interlocked control sample,GOMINs exhibit greater fracture strength(maximum stress:9.4 vs.3.6 MPa),higher toughness(22.3 vs.9.7 MJ/m^(3)),and increased elongation at break(359%vs.328%).Notably,despite these significant enhancements,GOMINs maintain good energy dissipation capacity and thermomechanical stability owing to the constrained intramolecular motion of mechanical bonds.This strategy endows GOMINs with distinctive properties,providing a promising platform for the design of advanced composite materials with enhanced and tunable multifunctionality.展开更多
基金financially supported by the National Natural Science Foundation of China (Nos. 52033011, 52173092 and 51973237)Natural Science Foundation of Guangdong Province(Nos. 2019B1515120038, 2020A1515011276 and 2021A1515010417)+4 种基金Science and Technology Planning Project of Guangzhou City (No. 202201011568)the Talented Program of Guizhou University (No. X2022008)Fundamental Research Funds for the Central Universities,Sun Yat-sen University (No. 23yxqntd002)GBRCE for Functional Molecular Engineering,the Youth Innovation Promotion Association,CAS(No. 2020010)Guangdong Basic and Applied Basic Research Foundation (No. 2021A1515110908)。
文摘Recently, we reported a series of reversibly interlocked polymer networks(RILNs), whose mechanical robustness and functionalities improvement was believed to be derived from topological interlocking of two sub-networks, although the direct evidence for the deduction is still lacking. Herein, a specially-designed RILNs system, in which the inter-component hydrogen bonds can be shielded as needed, was prepared and used to study the micro-structures of RILNs, aiming to verify the existence of mechanical interlocking in RILNs. By changing the pH of the swelling solvent, the effect exerted by the inter-component non-covalent bonds was eliminated, so detailed information of the networks structure was exposed. The small angle X-ray scattering(SAXS) and small-angle neutron scattering(SANS) results indicated that swelling-induced structural evolution of the two sub-networks mutually affected each other, even when the inter-component hydrogen bonds were absent, proving the presence of topological interlocking. The findings may help to draw a more accurate physical image and reveal the detailed structureproperty relationship of RILNs.
文摘Recently, literature on urban network research from the perspective of ?rm networks has been increasing. This research mainly used data from the headquarters and branches of all 2581 listed manufacturing companies in the Yangtze River Delta from 1990 to 2017, and studied the urban network through an interlocking network model that quantifies the links between enterprises. The results showed that the spatial distribution of listed manufacturing industries in the Yangtze River Delta was relatively concentrated, and cities such as Shanghai, Nanjing, and Hangzhou were hot spots for the spatial distribution of listed manufacturing industries. However, Fuyang, Suqian, Chizhou, Lishui and other network edge cities were less distributed in manufacturing. The urban network of the Yangtze River Delta has significant hierarchical characteristics. The urban network of the Yangtze River Delta presents a multi-center network development mode with Shanghai as the center and Nanjing, Hangzhou, and Hefei as the sub-centers. Moreover, we found that the development of inter-city connections in the Yangtze River Delta was driven by network mechanisms of priority attachment and path dependence. The radiating capacity and agglomeration capacity of cities in the Yangtze River Delta have a strong polarization characteristic. The core cities such as Shanghai, Nanjing, Hangzhou, and Hefei have much higher network radiation capabilities than network aggregation capabilities. However, other non-core cities and network edge cities have weak network radiation capabilities, and mainly accept network radiation from core cities. It enriches the research of urban networks based on real inter-?rm connections, and provides ideas for the wider regional study and the combination of econometric techniques and social network analysis.
文摘深入分析连锁董事网络演化动因及其作用机制对理解企业各种经营行为具有关键意义.基于社会网络分析方法,结合指数随机图模型(Exponential Random Graph Model,ERGM)和系统动力学(System Dynamics,SD)模型,对2010—2019年中国沪深A股上市企业连锁董事网络结构的演化特征、驱动因素及形成机制展开分析.研究结果表明:(1)我国连锁董事网络呈现持续扩张的趋势,具有高度社群化和小世界特性,网络结构具备一定韧性,在遭遇冲击后更倾向于建立轻量级联结;(2)通过对ERGM的分析发现,网络结构稳定并持续演化,监事会规模、两权分离率、地理距离与产权性质对网络形成及演化影响显著;(3)SD仿真结果显示,市场化进程和外部冲击促使企业增加董事联结以获取竞争优势和资源支持,中心度受企业间董事联结数量、多维邻近性及其滞后作用的多重影响,路径长度和外部冲击显著影响社区数量与聚类集群;外部冲击下,企业间董事联结数量、社区数量与聚类集群变化明显,而股权制衡度和两权分离率相对稳定.本研究解析的连锁董事网络的演化因素与形成机制对理解和解释企业行为提供了新视角和思路.
文摘研究基于DCS(Distributed Control System)的燃气-蒸汽联合循环机组运行智能控制系统,确保机组安全运行的同时,提高机组整体运行效率。构建基于DCS的燃气-蒸汽联合循环机组运行智能控制框架,过程控制层的Mark VI系统、DCS系统根据监测数据变化实现机组设备、旁路等自动控制。SIS层接收联合循环机组监测数据后,将其作为基于深度神经网络故障诊断模型的输入,实现机组设备故障的识别。在检测到故障时触发联锁保护子系统动作,将停机指令下达给自动启停控制子系统,使机组停止运行。实验结果表明,该系统可实现燃气-蒸汽联合循环机组设备故障识别,在100次训练后,训练损失为0.1左右,F-Score指标最大值为0.93;故障工况下,该系统可根据预定逻辑实现燃气-蒸汽联合循环机组自动停机。
基金support of the NSFC/China(22471164 and 52421006)the Shanghai Municipal Science and Technology Major Project,the NSF of Shanghai(22dz1207603)+5 种基金State Key Laboratory of Polyolefins and Catalysis and Shanghai Key Laboratory of Catalysis Technology for Polyolefins(SKL-LCTP-202301)Z.F.acknowledges the financial support of the China Postdoctoral Science Foundation(2024M761944).Z.acknowledges the financial support of Outstanding Doctoral Graduates Development Scholarship of Shanghai Jiao Tong University(SJTU Grants)Y.W.acknowledges the financial support of the NSFC/China(52403162)Z.Z.acknowledges the financial support of the NSFC/China(22475128 and 52333001)C.W.acknowledges the financial support of the NSFC/China(22505153).
文摘Mechanically interlocked networks(MINs)provide a versatile platform for engineering materials that combine mechanical strength with dynamic adaptability.Their performance hinges on the constrained intramolecular motion of mechanical bonds,so the deliberate selection of capping groups is essential for tailoring properties.Herein,we develop an innovative capping strategy for mechanical bonds by employing graphene oxide(GO)as the capping unit,enabling the construction of a new class of mechanically interlocked networks(GOMINs)with enhanced mechanical performance.GOMINs benefit both from the reinforcing effect of GO as a nanofiller and its innovative use as a capping unit that creates continuous mechanical bonds,collectively improving their mechanical strength and adaptability.Compared to the non-interlocked control sample,GOMINs exhibit greater fracture strength(maximum stress:9.4 vs.3.6 MPa),higher toughness(22.3 vs.9.7 MJ/m^(3)),and increased elongation at break(359%vs.328%).Notably,despite these significant enhancements,GOMINs maintain good energy dissipation capacity and thermomechanical stability owing to the constrained intramolecular motion of mechanical bonds.This strategy endows GOMINs with distinctive properties,providing a promising platform for the design of advanced composite materials with enhanced and tunable multifunctionality.
