High-performance proton exchange membranes are of great importance for fuel cells.Here,we have synthesized polycarboxylate plasticizer modified MIL-101-Cr-NH_(2)(PCP-MCN),a kind of hybrid metal-organic framework,which ...High-performance proton exchange membranes are of great importance for fuel cells.Here,we have synthesized polycarboxylate plasticizer modified MIL-101-Cr-NH_(2)(PCP-MCN),a kind of hybrid metal-organic framework,which exhibits a superior proton conductivity.PCP-MCN nanoparticles are used as additives to fabricate PCP-MCN/Nafion composite membranes.Microstructures and characteristics of PCP-MCN and these membranes have been extensively investigated.Significant enhancement in proton conduction for PCP-MCN around 55℃ is interestingly found due to the thermal motion of the PCP molecular chains.Robust mechanical properties and higher thermal decomposition temperature of the composite membranes are directly ascribed to strong intermolecular interactions between PCP-MCN and Nafion side chains,i.e.,the formation of substantial acid–base pairs(-SO_(3)^(-)…^(+)H–NH-),which further improves compatibility between additive and Nafion matrix.At the same humidity and temperature condition,the water uptake of composite membranes significantly increases due to the incorporation of porous additives with abundant functional groups and thus less crystallinity degree in comparison to pristine Nafion.Proton conductivity(σ)over wide ranges of humidities(30-100%RH at 25℃)and temperatures(30-98℃ at 100%RH)for prepared membranes is measured.The s in PCPMCN/Nafion composite membranes is remarkably enhanced,i.e.0.245 S/cm for PCP-MCN-3wt.%/Nafion is twice that of Nafion membrane at 98℃ and 100%RH,because of the establishment of well-interconnected proton transport ionic water channels and perhaps faster protonation–deprotonation processes.The composite membranes possess weak humidity-dependence of proton transport and higher water uptake due to excellent water retention ability of PCP-MCN.In particular,when 3 wt.%PCP-MCN was added to Nafion,the power density of a single-cell fabricated with this composite membrane reaches impressively 0.480,1.098 W/cm^(2) under 40%RH,100%RH at 60℃,respectively,guaranteeing it to be a promising proton exchange membrane.展开更多
In order to investigate the possible role of macrophages in pathological changes of cerebrovascular diseases, we observed and counted the numbers of perivascular macrophages in brains of spontaneously hypertensive rat...In order to investigate the possible role of macrophages in pathological changes of cerebrovascular diseases, we observed and counted the numbers of perivascular macrophages in brains of spontaneously hypertensive rats(SHR) and normotensive Wistar-Kyoto(WKY)rats using monoclon al antibodies(ED2)against rat macrophages.The immunohistochemistry(ABC method)and perfu sion-fixed frozen brain sections(16μm)were used in the study.The results showed that the ED2-specific staining in brain sections was restricted to macrophages in a perivascular location.The number of perivascular macrophages was significantly greater in SHR than in WKY.The results suggest that the hypertension is asseciated with increased subendothelial accumulation of macrophages.展开更多
IEC61850 is the most promising standard for design of power utility communication networks and automation systems. On the other hand multi-agent systems are attracting growing interest for different applications of po...IEC61850 is the most promising standard for design of power utility communication networks and automation systems. On the other hand multi-agent systems are attracting growing interest for different applications of power engineering. This paper presents the possibility that IEC61850 could be applied to build intelligent agents for power engineering applications. The paper investigates the correlation between IEC61850 and multi-agents and presents IEC61850 service tracking as a scenario. First, briefly introduces reporting and service tracking;then, investigates agents, intelligent agents and the characteristics of intelligent agents;last, analyzes the characteristics of service tracking and compares it with intelligent agents. And analysis shows that IEC61850 could be applied to build intelligent agents, which represents a significant step forward for MAS to apply in power engineering.展开更多
基金supported by the National Natural Science Foundation of China(NSFC)(Nos.12075172,12375288,12205089,and 12105048)National Key R&D Program of China(Grant No.2019YFA0210003)Guangdong Basic and Applied Basic Research Foundation(No.2020A1515110817).
文摘High-performance proton exchange membranes are of great importance for fuel cells.Here,we have synthesized polycarboxylate plasticizer modified MIL-101-Cr-NH_(2)(PCP-MCN),a kind of hybrid metal-organic framework,which exhibits a superior proton conductivity.PCP-MCN nanoparticles are used as additives to fabricate PCP-MCN/Nafion composite membranes.Microstructures and characteristics of PCP-MCN and these membranes have been extensively investigated.Significant enhancement in proton conduction for PCP-MCN around 55℃ is interestingly found due to the thermal motion of the PCP molecular chains.Robust mechanical properties and higher thermal decomposition temperature of the composite membranes are directly ascribed to strong intermolecular interactions between PCP-MCN and Nafion side chains,i.e.,the formation of substantial acid–base pairs(-SO_(3)^(-)…^(+)H–NH-),which further improves compatibility between additive and Nafion matrix.At the same humidity and temperature condition,the water uptake of composite membranes significantly increases due to the incorporation of porous additives with abundant functional groups and thus less crystallinity degree in comparison to pristine Nafion.Proton conductivity(σ)over wide ranges of humidities(30-100%RH at 25℃)and temperatures(30-98℃ at 100%RH)for prepared membranes is measured.The s in PCPMCN/Nafion composite membranes is remarkably enhanced,i.e.0.245 S/cm for PCP-MCN-3wt.%/Nafion is twice that of Nafion membrane at 98℃ and 100%RH,because of the establishment of well-interconnected proton transport ionic water channels and perhaps faster protonation–deprotonation processes.The composite membranes possess weak humidity-dependence of proton transport and higher water uptake due to excellent water retention ability of PCP-MCN.In particular,when 3 wt.%PCP-MCN was added to Nafion,the power density of a single-cell fabricated with this composite membrane reaches impressively 0.480,1.098 W/cm^(2) under 40%RH,100%RH at 60℃,respectively,guaranteeing it to be a promising proton exchange membrane.
文摘In order to investigate the possible role of macrophages in pathological changes of cerebrovascular diseases, we observed and counted the numbers of perivascular macrophages in brains of spontaneously hypertensive rats(SHR) and normotensive Wistar-Kyoto(WKY)rats using monoclon al antibodies(ED2)against rat macrophages.The immunohistochemistry(ABC method)and perfu sion-fixed frozen brain sections(16μm)were used in the study.The results showed that the ED2-specific staining in brain sections was restricted to macrophages in a perivascular location.The number of perivascular macrophages was significantly greater in SHR than in WKY.The results suggest that the hypertension is asseciated with increased subendothelial accumulation of macrophages.
文摘IEC61850 is the most promising standard for design of power utility communication networks and automation systems. On the other hand multi-agent systems are attracting growing interest for different applications of power engineering. This paper presents the possibility that IEC61850 could be applied to build intelligent agents for power engineering applications. The paper investigates the correlation between IEC61850 and multi-agents and presents IEC61850 service tracking as a scenario. First, briefly introduces reporting and service tracking;then, investigates agents, intelligent agents and the characteristics of intelligent agents;last, analyzes the characteristics of service tracking and compares it with intelligent agents. And analysis shows that IEC61850 could be applied to build intelligent agents, which represents a significant step forward for MAS to apply in power engineering.
