解决阴影效应和多径效应一直是研究可见光通信系统的关键。提出利用MIMO(Multi Input Multi Output)技术扩大通信过程中信号传输的信道容量,配合LED的高强度光线,实现室内光照的大面积覆盖和抗阴影能力。而OFDM(Orthogonal Frequency Di...解决阴影效应和多径效应一直是研究可见光通信系统的关键。提出利用MIMO(Multi Input Multi Output)技术扩大通信过程中信号传输的信道容量,配合LED的高强度光线,实现室内光照的大面积覆盖和抗阴影能力。而OFDM(Orthogonal Frequency Division Multiplexing)的调制方式,它的循环前缀能够解决光信号在室内传播过程中引起的多径效应,降低码间干扰的强度,并提高频谱利用率,解决了LED芯片可调制宽带不足的问题。与传统的室内光通信相比,提出利用MIMO-OFDM的编码方式能够提高可见光通信系统在室内的通信水平,并且在保证光照强度的同时实现信号的高信噪比传输。展开更多
The rational design of efficient heterogeneous catalysts for Friedel-Crafts acylation reactions is highly desirable for meeting the need for the industrial production of various aromatic ketone compounds and biomass-d...The rational design of efficient heterogeneous catalysts for Friedel-Crafts acylation reactions is highly desirable for meeting the need for the industrial production of various aromatic ketone compounds and biomass-derived chemicals.Herein,we reported that graphitic carbon wrapped FeCo bimetallic nanoparticles confined in nitrogen-doped carbon nanotubes,which were prepared by pyrolysis of FeCo-based Prussian blue analogue and melamine via a two-stage programmed heating procedure,exhibited excellent catalytic activity and recyclability for the acylation of aromatic compounds with acyl chlorides.The oxidized bimetallic species embedded in the external graphitic carbon shell should be the main active sites for the acylation reaction.The graphitic carbon shell and the carbon nanotube could provide effective protection on the active metal species against leaching through multiple interactions,leading to the formation of a highly active and durable heterogeneous catalyst for the acylation reaction.展开更多
文摘解决阴影效应和多径效应一直是研究可见光通信系统的关键。提出利用MIMO(Multi Input Multi Output)技术扩大通信过程中信号传输的信道容量,配合LED的高强度光线,实现室内光照的大面积覆盖和抗阴影能力。而OFDM(Orthogonal Frequency Division Multiplexing)的调制方式,它的循环前缀能够解决光信号在室内传播过程中引起的多径效应,降低码间干扰的强度,并提高频谱利用率,解决了LED芯片可调制宽带不足的问题。与传统的室内光通信相比,提出利用MIMO-OFDM的编码方式能够提高可见光通信系统在室内的通信水平,并且在保证光照强度的同时实现信号的高信噪比传输。
基金supported by the National Natural Science Foundation of China(No.22172058)。
文摘The rational design of efficient heterogeneous catalysts for Friedel-Crafts acylation reactions is highly desirable for meeting the need for the industrial production of various aromatic ketone compounds and biomass-derived chemicals.Herein,we reported that graphitic carbon wrapped FeCo bimetallic nanoparticles confined in nitrogen-doped carbon nanotubes,which were prepared by pyrolysis of FeCo-based Prussian blue analogue and melamine via a two-stage programmed heating procedure,exhibited excellent catalytic activity and recyclability for the acylation of aromatic compounds with acyl chlorides.The oxidized bimetallic species embedded in the external graphitic carbon shell should be the main active sites for the acylation reaction.The graphitic carbon shell and the carbon nanotube could provide effective protection on the active metal species against leaching through multiple interactions,leading to the formation of a highly active and durable heterogeneous catalyst for the acylation reaction.
