随着电力市场化改革的推进,微电网或拥有分布式发电的用户作为售电主体,被允许参与电能市场交易。但现有条件下的电能交易面临着缺乏信任和中心化的问题,区块链技术作为一种全新的分布式加密方式,对实现用户之间公平、点对点、实时、去...随着电力市场化改革的推进,微电网或拥有分布式发电的用户作为售电主体,被允许参与电能市场交易。但现有条件下的电能交易面临着缺乏信任和中心化的问题,区块链技术作为一种全新的分布式加密方式,对实现用户之间公平、点对点、实时、去信任的能量交易具有重要意义。文章首先介绍已有的区块链电能交易项目,分析对比了可供开发者使用的区块链即服务(blockchain as a service,BaaS)平台;然后对应用区块链技术的端对端电能交易网络和交易算法进行设计,分析了区块链即服务平台的应用过程;最后以一园区3个分布式光伏用户的运行实例,说明区块链技术下微网电能交易去中心化、透明化、难以篡改的特点,及其在促进微电网安全高效运行,社会利益最大化的有效性。展开更多
Decoupling electrical and thermal properties to enhance the figure of merit of thermoelectric materials underscores an in-depth understanding of the mechanisms that govern the transfer of charge carriers.Typically,a f...Decoupling electrical and thermal properties to enhance the figure of merit of thermoelectric materials underscores an in-depth understanding of the mechanisms that govern the transfer of charge carriers.Typically,a factor that contributes to the optimization of thermal conductivity is often found to be detrimental to the electrical transport properties.Here,we systematically investigated 26 dimeric MX_(2)-type compounds(where M represents a metal and X represents a nonmetal element)to explore the influence of the electronic configurations of metal cations on lattice thermal transport and thermoelectric performance using first-principles calculations.A principled scheme has been identified that the filled outer orbitals of the cation lead to a significantly lower lattice thermal conductivity compared to that of the partly occupied case for MX_(2),due to the much weakened bonds manifested by the shallow potential well,smaller interatomic force constants,and higher atomic displacement parameters.Based on these findings,we propose two ionic compounds,BaAs and BaSe_(2),to realize reasonable high electrical conductivities through the structural anisotropy caused by the inserted covalent X_(2) dimers while still maintaining the large lattice anharmonicity.The combined superior electrical and thermal properties of BaSe_(2) lead to a high n-type thermoelectric ZT value of 2.3 at 500 K.This work clarifies the structural origin of the heat transport properties of dimeric MX_(2)-type compounds and provides an insightful strategy for developing promising thermoelectric materials.展开更多
文摘随着电力市场化改革的推进,微电网或拥有分布式发电的用户作为售电主体,被允许参与电能市场交易。但现有条件下的电能交易面临着缺乏信任和中心化的问题,区块链技术作为一种全新的分布式加密方式,对实现用户之间公平、点对点、实时、去信任的能量交易具有重要意义。文章首先介绍已有的区块链电能交易项目,分析对比了可供开发者使用的区块链即服务(blockchain as a service,BaaS)平台;然后对应用区块链技术的端对端电能交易网络和交易算法进行设计,分析了区块链即服务平台的应用过程;最后以一园区3个分布式光伏用户的运行实例,说明区块链技术下微网电能交易去中心化、透明化、难以篡改的特点,及其在促进微电网安全高效运行,社会利益最大化的有效性。
基金financial support from the Natural Science Foundation of China(No.11904089,12174092,11674087)the Overseas Expertise Introduction Center for Discipline Innovation(D18025)+1 种基金the Program for Key Research and Development of Science and Technology in Hubei Province(grant No.2023BEB002)supported by the Young Science Foundation of Hubei University(Grant No.430/184303000047).
文摘Decoupling electrical and thermal properties to enhance the figure of merit of thermoelectric materials underscores an in-depth understanding of the mechanisms that govern the transfer of charge carriers.Typically,a factor that contributes to the optimization of thermal conductivity is often found to be detrimental to the electrical transport properties.Here,we systematically investigated 26 dimeric MX_(2)-type compounds(where M represents a metal and X represents a nonmetal element)to explore the influence of the electronic configurations of metal cations on lattice thermal transport and thermoelectric performance using first-principles calculations.A principled scheme has been identified that the filled outer orbitals of the cation lead to a significantly lower lattice thermal conductivity compared to that of the partly occupied case for MX_(2),due to the much weakened bonds manifested by the shallow potential well,smaller interatomic force constants,and higher atomic displacement parameters.Based on these findings,we propose two ionic compounds,BaAs and BaSe_(2),to realize reasonable high electrical conductivities through the structural anisotropy caused by the inserted covalent X_(2) dimers while still maintaining the large lattice anharmonicity.The combined superior electrical and thermal properties of BaSe_(2) lead to a high n-type thermoelectric ZT value of 2.3 at 500 K.This work clarifies the structural origin of the heat transport properties of dimeric MX_(2)-type compounds and provides an insightful strategy for developing promising thermoelectric materials.
