针对低轨卫星高动态场景下多服务质量(Quality of Service,QoS)时变物联业务资源调度问题,提出了一种基于Lyapunov优化的窄带物联网(Narrow Band Internet of Things,NB-IoT)多业务资源切片动态管理方法。该方法综合考虑多物联业务QoS...针对低轨卫星高动态场景下多服务质量(Quality of Service,QoS)时变物联业务资源调度问题,提出了一种基于Lyapunov优化的窄带物联网(Narrow Band Internet of Things,NB-IoT)多业务资源切片动态管理方法。该方法综合考虑多物联业务QoS需求、不同QoS业务队列状态以及切片大小的动态划分,构建了资源切片动态管理的资源调度优化问题。基于Lyapunov优化理论将非凸的多时隙动态资源切片划分问题转化为单时隙多QoS业务资源切片配置问题,从而在动态业务场景下实现资源切片与多QoS业务队列之间的动态适配。仿真结果表明,与传统NB-IoT上行资源调度方法相比,所提方法在低轨高动态场景下能够显著提升时延确定性业务的QoS保障和吞吐量。展开更多
Pyridine-based agrochemical products have become the most commercially successful in the 21st century.About half of the agrochemicals with pyridine scaffold were released,registered or invented only in the current mil...Pyridine-based agrochemical products have become the most commercially successful in the 21st century.About half of the agrochemicals with pyridine scaffold were released,registered or invented only in the current millennium.Some of them have a unique structure and previously unknown modes of action.The literature provides examples of the use of the pyridine ring in pesticides for reducing the dosage of the active ingredient,hence to take care of the environment due to their increased efficacy,overcoming the pest resistance,and also makes it possible to create patentable structures by dodging the parent patent,which sometimes leads to a change in the spectrum of activity of the compounds.The newest 13 substances registered by the ISO from January 2021 to June 2024,and not reviewed previously are considered.展开更多
The poor reversibility and stability of Zn anodes greatly restrict the practical application of aqueous Zn-ion batteries(AZIBs),resulting from the uncontrollable dendrite growth and H_(2)O-induced side reactions durin...The poor reversibility and stability of Zn anodes greatly restrict the practical application of aqueous Zn-ion batteries(AZIBs),resulting from the uncontrollable dendrite growth and H_(2)O-induced side reactions during cycling.Electrolyte additive modification is considered one of the most effective and simplest methods for solving the aforementioned problems.Herein,the pyridine derivatives(PD)including 2,4-dihydroxypyridine(2,4-DHP),2,3-dihydroxypyridine(2,3-DHP),and 2-hydroxypyrdine(2-DHP),were em-ployed as novel electrolyte additives in ZnSO_(4)electrolyte.Both density functional theory calculation and experimental findings demonstrated that the incorporation of PD additives into the electrolyte effectively modulates the solvation structure of hydrated Zn ions,thereby suppressing side reactions in AZIBs.Ad-ditionally,the adsorption of PD molecules on the zinc anode surface contributed to uniform Zn deposi-tion and dendrite growth inhibition.Consequently,a 2,4-DHP-modified Zn/Zn symmetrical cell achieved an extremely long cyclic stability up to 5650 h at 1 mA cm^(-2).Furthermore,the Zn/NH_(4)V_(4)O_(10)full cell with 2,4-DHP-containing electrolyte exhibited an outstanding initial capacity of 204 mAh g^(-1),with a no-table capacity retention of 79%after 1000 cycles at 5 A g^(-1).Hence,this study expands the selection of electrolyte additives for AZIBs,and the working mechanism of PD additives provides new insights for electrolyte modification enabling highly reversible zinc anode.展开更多
The light-driven CO_(2)reduction reaction(CO_(2)RR)to CO is a very effective way to address global warming.To avoid competition with water photolysis,metal-free gas-solid CO_(2)RR catalysts should be investigated.Cova...The light-driven CO_(2)reduction reaction(CO_(2)RR)to CO is a very effective way to address global warming.To avoid competition with water photolysis,metal-free gas-solid CO_(2)RR catalysts should be investigated.Covalent organic frameworks(COFs)offer a promising approach for CO_(2)transformation but lack high efficiency and selectivity in the absence of metals.Here,we have incorporated a pyridine nitrogen component into the imine-COF conjugated structure(Tp Pym).This innovative system has set a record of producing a CO yield of 1565μmol g^(-1)within 6 h.The soft X-ray absorption fine structure measurement proves that Tp Pym has both better conjugation and electron cloud enrichment.The electronic structure distribution delays the charge-carrier recombination,as evidenced by femtosecond transient absorption spectroscopy.The energy band diagram and theoretical calculation show that the conduction-band potential of Tp Pym is lower and the reduction reaction of CO_(2)to CO is more likely to occur.展开更多
Lithium-ion(Li-ion)battery using a graphite(Gr.)anode and a lithium iron phosphate(LiFePO4,LFP)cathode(Gr.||LFP)has been widespread in energy storage.To match the warranty period of energy storage systems,the lifespan...Lithium-ion(Li-ion)battery using a graphite(Gr.)anode and a lithium iron phosphate(LiFePO4,LFP)cathode(Gr.||LFP)has been widespread in energy storage.To match the warranty period of energy storage systems,the lifespan of this kind of Li-ion battery,not only under room temperature but also under relatively high temperature,is critical.Exploration of func-tional electrolyte additive provides an efficient approach to address this issue.This study reports the usage of pyridine(Py)as a new electrolyte functional additive for Gr.||LFP.In the first cycle,it was found that Py can be reduced before ethylene carbonate and vinylene carbonate,forming a dense and homogeneous solid electrolyte interface(SEI)layer containing rich nitrogen and fluorine elements.Owing to the merits of the SEI layer,the parasitic reactions which occur at the graphite anode and consume the active lithium ion during cycling were suppressed.With the amount of 0.5wt%Py additive in the electrolyte,the Gr.||LFP pouch cell achieved a capacity of 3.2 Ah,exhibiting remarkablly enhanced cycling stability and high-temperature storage capability.Under the experimental conditions of 25°C and 0.5 P,the capacity retention of the pouch cell reached 95.64%after 500 cycles,while still maintained 82.75%of the initial capacity after 1000 cycles under 45°C and 1 P.After the 30-day storage at 45°C and 60°C,the capacity retention rates were 87.38%and 80.56%,respectively,which are significantly higher than those of the pouch cells with the blank control electrolyte.This work identifies Py as a highly promising electrolyte additive in stabilizing the graphite-based anode of Li-ion battery under both room temperature and high temperature.展开更多
文摘针对低轨卫星高动态场景下多服务质量(Quality of Service,QoS)时变物联业务资源调度问题,提出了一种基于Lyapunov优化的窄带物联网(Narrow Band Internet of Things,NB-IoT)多业务资源切片动态管理方法。该方法综合考虑多物联业务QoS需求、不同QoS业务队列状态以及切片大小的动态划分,构建了资源切片动态管理的资源调度优化问题。基于Lyapunov优化理论将非凸的多时隙动态资源切片划分问题转化为单时隙多QoS业务资源切片配置问题,从而在动态业务场景下实现资源切片与多QoS业务队列之间的动态适配。仿真结果表明,与传统NB-IoT上行资源调度方法相比,所提方法在低轨高动态场景下能够显著提升时延确定性业务的QoS保障和吞吐量。
文摘Pyridine-based agrochemical products have become the most commercially successful in the 21st century.About half of the agrochemicals with pyridine scaffold were released,registered or invented only in the current millennium.Some of them have a unique structure and previously unknown modes of action.The literature provides examples of the use of the pyridine ring in pesticides for reducing the dosage of the active ingredient,hence to take care of the environment due to their increased efficacy,overcoming the pest resistance,and also makes it possible to create patentable structures by dodging the parent patent,which sometimes leads to a change in the spectrum of activity of the compounds.The newest 13 substances registered by the ISO from January 2021 to June 2024,and not reviewed previously are considered.
基金supported by the Key Science and Technol-ogy Program of Henan Province(No.232102241020)the Ph.D.Research Startup Foundation of Henan University of Science and Technology(No.400613480015)+1 种基金the Postdoctoral Research Startup Foundation of Henan University of Science and Technology(No.400613554001)the Natural Science Foundation of Henan Province(242300420021).
文摘The poor reversibility and stability of Zn anodes greatly restrict the practical application of aqueous Zn-ion batteries(AZIBs),resulting from the uncontrollable dendrite growth and H_(2)O-induced side reactions during cycling.Electrolyte additive modification is considered one of the most effective and simplest methods for solving the aforementioned problems.Herein,the pyridine derivatives(PD)including 2,4-dihydroxypyridine(2,4-DHP),2,3-dihydroxypyridine(2,3-DHP),and 2-hydroxypyrdine(2-DHP),were em-ployed as novel electrolyte additives in ZnSO_(4)electrolyte.Both density functional theory calculation and experimental findings demonstrated that the incorporation of PD additives into the electrolyte effectively modulates the solvation structure of hydrated Zn ions,thereby suppressing side reactions in AZIBs.Ad-ditionally,the adsorption of PD molecules on the zinc anode surface contributed to uniform Zn deposi-tion and dendrite growth inhibition.Consequently,a 2,4-DHP-modified Zn/Zn symmetrical cell achieved an extremely long cyclic stability up to 5650 h at 1 mA cm^(-2).Furthermore,the Zn/NH_(4)V_(4)O_(10)full cell with 2,4-DHP-containing electrolyte exhibited an outstanding initial capacity of 204 mAh g^(-1),with a no-table capacity retention of 79%after 1000 cycles at 5 A g^(-1).Hence,this study expands the selection of electrolyte additives for AZIBs,and the working mechanism of PD additives provides new insights for electrolyte modification enabling highly reversible zinc anode.
基金supported by the National Natural Science Foundation of China(Nos.22375031,22202037,22472023)the Fundamental Research Funds for the Central Universities(Nos.2412023YQ001,2412023QD019,2412024QD014)+1 种基金supported by grants from the seventh batch of Jilin Province Youth Science and Technology Talent Lifting Project(No.QT202305)Science and Technology Development Plan Project of Jilin Province,China(No.20240101192JC)。
文摘The light-driven CO_(2)reduction reaction(CO_(2)RR)to CO is a very effective way to address global warming.To avoid competition with water photolysis,metal-free gas-solid CO_(2)RR catalysts should be investigated.Covalent organic frameworks(COFs)offer a promising approach for CO_(2)transformation but lack high efficiency and selectivity in the absence of metals.Here,we have incorporated a pyridine nitrogen component into the imine-COF conjugated structure(Tp Pym).This innovative system has set a record of producing a CO yield of 1565μmol g^(-1)within 6 h.The soft X-ray absorption fine structure measurement proves that Tp Pym has both better conjugation and electron cloud enrichment.The electronic structure distribution delays the charge-carrier recombination,as evidenced by femtosecond transient absorption spectroscopy.The energy band diagram and theoretical calculation show that the conduction-band potential of Tp Pym is lower and the reduction reaction of CO_(2)to CO is more likely to occur.
基金supported by the Significant Science and Technology Project in Xiamen(Future Industry Field)(Grant No.3502Z20231057).
文摘Lithium-ion(Li-ion)battery using a graphite(Gr.)anode and a lithium iron phosphate(LiFePO4,LFP)cathode(Gr.||LFP)has been widespread in energy storage.To match the warranty period of energy storage systems,the lifespan of this kind of Li-ion battery,not only under room temperature but also under relatively high temperature,is critical.Exploration of func-tional electrolyte additive provides an efficient approach to address this issue.This study reports the usage of pyridine(Py)as a new electrolyte functional additive for Gr.||LFP.In the first cycle,it was found that Py can be reduced before ethylene carbonate and vinylene carbonate,forming a dense and homogeneous solid electrolyte interface(SEI)layer containing rich nitrogen and fluorine elements.Owing to the merits of the SEI layer,the parasitic reactions which occur at the graphite anode and consume the active lithium ion during cycling were suppressed.With the amount of 0.5wt%Py additive in the electrolyte,the Gr.||LFP pouch cell achieved a capacity of 3.2 Ah,exhibiting remarkablly enhanced cycling stability and high-temperature storage capability.Under the experimental conditions of 25°C and 0.5 P,the capacity retention of the pouch cell reached 95.64%after 500 cycles,while still maintained 82.75%of the initial capacity after 1000 cycles under 45°C and 1 P.After the 30-day storage at 45°C and 60°C,the capacity retention rates were 87.38%and 80.56%,respectively,which are significantly higher than those of the pouch cells with the blank control electrolyte.This work identifies Py as a highly promising electrolyte additive in stabilizing the graphite-based anode of Li-ion battery under both room temperature and high temperature.
