Electrocatalytic reduction of nitrate to ammonia has been considered a promising and sustainable pathway for pollutant treatment and ammonia has significant potential as a clean energy.Therefore,the method has receive...Electrocatalytic reduction of nitrate to ammonia has been considered a promising and sustainable pathway for pollutant treatment and ammonia has significant potential as a clean energy.Therefore,the method has received much attention.In this work,Cu/Fe 2D bimetallic metal-organic frameworks were synthesized by a facile method applied as cathode materials without high-temperature carbonization.Bimetallic centers(Cu,Fe)with enhanced intrinsic activity demonstrated higher removal efficiency.Meanwhile,the 2D nanosheet reduced themass transfer barrier between the catalyst and nitrate and increased the reaction kinetics.Therefore,the catalysts with a 2D structure showed much better removal efficiency than other structures(3D MOFs and BulkMOFs).Under optimal conditions,Cu/Fe-2D MOF exhibited high nitrate removal efficiency(87.8%)and ammonium selectivity(89.3%)simultaneously.The ammonium yielded up to significantly 907.2μg/(hr·mg_(cat))(7793.8μg/(hr·mg_(metal)))with Faradaic efficiency of 62.8%at an initial 100 mg N/L.The catalyst was proved to have good stability and was recycled 15 times with excellent effect.DFT simulations confirm the reduced Gibbs free energy of Cu/Fe-2D MOF.This study demonstrates the promising application of Cu/Fe-2D MOF in nitrate reduction to ammonia and provides new insights for the design of efficient electrode materials.展开更多
The hydrogen-bonded organic frameworks(HOFs)as a new type of porous framework materials have been widely studied in various areas.However,the lack of appropriate active sites,low intrinsic conductivity,and poor stabil...The hydrogen-bonded organic frameworks(HOFs)as a new type of porous framework materials have been widely studied in various areas.However,the lack of appropriate active sites,low intrinsic conductivity,and poor stability limited their performance in the field of electrocatalysis.Herein,we designed two 2D metal hydrogen-bonded organic frameworks(2D–M–HOF,M=Cu^(2+)or Ni^(2+))with coordination compounds based on 2,3,6,7,14,15-hexahydroxyl cyclotricatechylene and transition metal ions(Cu^(2+)and Ni^(2+)),respectively.The crystal structure of 2D–Cu–HOF is determined by continuous rotation electron diffraction,indicating an undulated 2D hydrogen-bond network with interlayeredπ-πstacking.The flexible structure of 2D–M–HOF leads to the formation of self-adaption interlayered sites,resulting in superior activity and selectivity in the electrocatalytic conversion of CO_(2) to C_(2) products,achieving a total Faradaic efficiency exceeding 80%due to the high-efficiency C–C coupling.The experimental results and density functional calculations verify that the undulated 2D–M–HOF enables the energetically favorable formation of*OCCHO intermediate.This work provides a promising strategy for designing HOF catalysts in electrocatalysis and related processes.展开更多
Metal-organic frameworks(MOFs),assembled periodically by coordinating inorganic metal ions and organic motifs,have arisen widespread curiosity and intensive investigation owing to their tailorable electronic propertie...Metal-organic frameworks(MOFs),assembled periodically by coordinating inorganic metal ions and organic motifs,have arisen widespread curiosity and intensive investigation owing to their tailorable electronic properties and well-defined topological structure.However,the majority of MOFs are intrinsically dielectric or insulative[1]and typically form as 3D bulk or powder crystals,making them incompatible with complementary metal-oxide semiconductor(CMOS)techniques.In recent years,layer-stacked two-dimensional conjugated MOFs(2D c-MOFs),composed of planar conjugated ligands and linkages[2],have demonstrated high in-plane π conjugation and weak out-of-plane van der Waals interactions,due to their long-range electron delocalization over metal ions and ligands[3].As a result,highly tunable band gaps from semiconductor to conductor,modulable porosity from micropore to macropore and versatile processability into conductive 2D thin films with controllable lateral thickness and domain size are presented,rendering charming potential for applications in(opto-)electronics compared with classic 2D metal oxide,chalcogenide and crystalline polymer materials.To improve interfacial charge-transport and precisely tune the charge extraction and band alignment of 2D c-MOFs in(opto-)electronic devices[4],developing highly efficient synthetic methods of 2D c-MOFs is of utmost importance.展开更多
为研发同时预防和控制猪圆环病毒2d基因型(PCV2d)和猪伪狂犬病病毒(PRV)的疫苗,将PCV2dORF2基因克隆到含有绿色荧光蛋白(EGFP)基因的PRV转移质粒pG中BamHⅠ位点,获得重组质粒pG-PCV2d-EGFP。运用转染试剂ZLip2000将其与PRV变异株3基因...为研发同时预防和控制猪圆环病毒2d基因型(PCV2d)和猪伪狂犬病病毒(PRV)的疫苗,将PCV2dORF2基因克隆到含有绿色荧光蛋白(EGFP)基因的PRV转移质粒pG中BamHⅠ位点,获得重组质粒pG-PCV2d-EGFP。运用转染试剂ZLip2000将其与PRV变异株3基因缺失毒株gE^(-)/g^(-)/TK^(-)PRV NY DNA转入ST细胞中,经绿色荧光蚀斑纯化,得到表达EGFP的重组病毒rPRV-PCV2d-EGFP。采用CRISPR/Cas9基因双敲除质粒敲除重组病毒中EGFP基因,经蚀斑纯化,拯救出不表达EGFP的重组病毒rPRV-PCV2d。重组病毒rPRV-PCV2d与亲本株gE^(-)/g^(-)/TK^(-)PRV NY具有相近的遗传稳定性,且能够表达PCV2d衣壳(Cap)蛋白。在6周龄小鼠免疫试验中,与商品化PCV2灭活疫苗相比,rPRV-PCV2d刺激小鼠机体诱导了更高的PCV2特异性抗体,且用PCV2d强毒株攻毒后,rPRV-PCV2d显著降低了小鼠心脏、肝脏、脾脏等组织中PCV2d载量。此外,rPRV-PCV2d在小鼠体内激发PRV特异性免疫应答,并能阻止PRV强毒对小鼠的侵袭。表明rPRV-PCV2d具有良好的免疫原性。展开更多
传统的功率分配算法由于复杂的矩阵运算与迭代所造成的高时延,在实际通信中实时获取信道信息十分困难,当前重要的研究方向是在系统性能和计算复杂度之间找到有效平衡。针对终端直通(Device-to-Device,D2D)用户与蜂窝用户的联合功率分配...传统的功率分配算法由于复杂的矩阵运算与迭代所造成的高时延,在实际通信中实时获取信道信息十分困难,当前重要的研究方向是在系统性能和计算复杂度之间找到有效平衡。针对终端直通(Device-to-Device,D2D)用户与蜂窝用户的联合功率分配问题,提出一种异构功率控制图神经网络(Heterogeneous Power Control Graph Neural Network,HPCGNN)算法,旨在最大化所有用户的加权和速率。首先通过构建干扰的异构图,将信道和噪声等信息嵌入到图的节点和边;再由HPCGNN完成消息传递和更新,采用无监督学习方式优化深度神经网络(Deep Neural Network,DNN)参数,最终得到最佳的功率分配。仿真结果表明,相较于其他深度学习算法,所提算法能够有效提高系统性能,且在损失5%性能下相较分式规划(Fractional Programming,FP)能降低82%~98%的时间复杂度。展开更多
对D2D(Device to Device)通信系统的隐蔽通信问题进行研究,提出了一种基于智能反射面(Intelligent Reflecting Surfaces,IRS)的D2D通信系统,该系统采用双IRS模式。首先分析了各信号的信干噪比(SINR)和各自的期望值,并据此推导出系统遍...对D2D(Device to Device)通信系统的隐蔽通信问题进行研究,提出了一种基于智能反射面(Intelligent Reflecting Surfaces,IRS)的D2D通信系统,该系统采用双IRS模式。首先分析了各信号的信干噪比(SINR)和各自的期望值,并据此推导出系统遍历总容量的解形式,接着针对隐蔽通信建立了二元假设问题,推导出误检测率的解形式,并据此计算出平均最小误检测率。除此之外,还分析了无IRS系统的遍历总容量和平均最小误检测率,与双IRS系统进行对比。仿真结果表明,双IRS系统的遍历总容量和平均最小误检测率优于无IRS系统,双IRS系统能够比传统的无IRS系统获得更高的容量和更低的误检测率。展开更多
基金supported by the National Natural Science Foundation of China(NSFC)(Nos.52370044 and 21976134)the State Key Laboratory of Pollution Control and Resource Reuse Foundation(Nos.PCRRK21003 and PCRRK21001)+1 种基金Shanghai Scientific Research Plan Project(No.23ZR1467000)the State Key Laboratory of Treatments and Recycling for Organic Effluents by Adsorption in Petroleum and Chemical Industry(No.SDHY2206).
文摘Electrocatalytic reduction of nitrate to ammonia has been considered a promising and sustainable pathway for pollutant treatment and ammonia has significant potential as a clean energy.Therefore,the method has received much attention.In this work,Cu/Fe 2D bimetallic metal-organic frameworks were synthesized by a facile method applied as cathode materials without high-temperature carbonization.Bimetallic centers(Cu,Fe)with enhanced intrinsic activity demonstrated higher removal efficiency.Meanwhile,the 2D nanosheet reduced themass transfer barrier between the catalyst and nitrate and increased the reaction kinetics.Therefore,the catalysts with a 2D structure showed much better removal efficiency than other structures(3D MOFs and BulkMOFs).Under optimal conditions,Cu/Fe-2D MOF exhibited high nitrate removal efficiency(87.8%)and ammonium selectivity(89.3%)simultaneously.The ammonium yielded up to significantly 907.2μg/(hr·mg_(cat))(7793.8μg/(hr·mg_(metal)))with Faradaic efficiency of 62.8%at an initial 100 mg N/L.The catalyst was proved to have good stability and was recycled 15 times with excellent effect.DFT simulations confirm the reduced Gibbs free energy of Cu/Fe-2D MOF.This study demonstrates the promising application of Cu/Fe-2D MOF in nitrate reduction to ammonia and provides new insights for the design of efficient electrode materials.
基金financially supported by the National Natural Science Foundation of China(nos.21971012,61933002,21601015,21625102,21674012,and 81601549)the National Key Research and Development Program of China(2020YFB1506300)Beijing Institute of Technology Research Fund Program for Young Scholars。
文摘The hydrogen-bonded organic frameworks(HOFs)as a new type of porous framework materials have been widely studied in various areas.However,the lack of appropriate active sites,low intrinsic conductivity,and poor stability limited their performance in the field of electrocatalysis.Herein,we designed two 2D metal hydrogen-bonded organic frameworks(2D–M–HOF,M=Cu^(2+)or Ni^(2+))with coordination compounds based on 2,3,6,7,14,15-hexahydroxyl cyclotricatechylene and transition metal ions(Cu^(2+)and Ni^(2+)),respectively.The crystal structure of 2D–Cu–HOF is determined by continuous rotation electron diffraction,indicating an undulated 2D hydrogen-bond network with interlayeredπ-πstacking.The flexible structure of 2D–M–HOF leads to the formation of self-adaption interlayered sites,resulting in superior activity and selectivity in the electrocatalytic conversion of CO_(2) to C_(2) products,achieving a total Faradaic efficiency exceeding 80%due to the high-efficiency C–C coupling.The experimental results and density functional calculations verify that the undulated 2D–M–HOF enables the energetically favorable formation of*OCCHO intermediate.This work provides a promising strategy for designing HOF catalysts in electrocatalysis and related processes.
基金supported by the National Natural Science Foundation of China(Nos.22201086,22471084,92261204,21925104,and 22431005).
文摘Metal-organic frameworks(MOFs),assembled periodically by coordinating inorganic metal ions and organic motifs,have arisen widespread curiosity and intensive investigation owing to their tailorable electronic properties and well-defined topological structure.However,the majority of MOFs are intrinsically dielectric or insulative[1]and typically form as 3D bulk or powder crystals,making them incompatible with complementary metal-oxide semiconductor(CMOS)techniques.In recent years,layer-stacked two-dimensional conjugated MOFs(2D c-MOFs),composed of planar conjugated ligands and linkages[2],have demonstrated high in-plane π conjugation and weak out-of-plane van der Waals interactions,due to their long-range electron delocalization over metal ions and ligands[3].As a result,highly tunable band gaps from semiconductor to conductor,modulable porosity from micropore to macropore and versatile processability into conductive 2D thin films with controllable lateral thickness and domain size are presented,rendering charming potential for applications in(opto-)electronics compared with classic 2D metal oxide,chalcogenide and crystalline polymer materials.To improve interfacial charge-transport and precisely tune the charge extraction and band alignment of 2D c-MOFs in(opto-)electronic devices[4],developing highly efficient synthetic methods of 2D c-MOFs is of utmost importance.
文摘为研发同时预防和控制猪圆环病毒2d基因型(PCV2d)和猪伪狂犬病病毒(PRV)的疫苗,将PCV2dORF2基因克隆到含有绿色荧光蛋白(EGFP)基因的PRV转移质粒pG中BamHⅠ位点,获得重组质粒pG-PCV2d-EGFP。运用转染试剂ZLip2000将其与PRV变异株3基因缺失毒株gE^(-)/g^(-)/TK^(-)PRV NY DNA转入ST细胞中,经绿色荧光蚀斑纯化,得到表达EGFP的重组病毒rPRV-PCV2d-EGFP。采用CRISPR/Cas9基因双敲除质粒敲除重组病毒中EGFP基因,经蚀斑纯化,拯救出不表达EGFP的重组病毒rPRV-PCV2d。重组病毒rPRV-PCV2d与亲本株gE^(-)/g^(-)/TK^(-)PRV NY具有相近的遗传稳定性,且能够表达PCV2d衣壳(Cap)蛋白。在6周龄小鼠免疫试验中,与商品化PCV2灭活疫苗相比,rPRV-PCV2d刺激小鼠机体诱导了更高的PCV2特异性抗体,且用PCV2d强毒株攻毒后,rPRV-PCV2d显著降低了小鼠心脏、肝脏、脾脏等组织中PCV2d载量。此外,rPRV-PCV2d在小鼠体内激发PRV特异性免疫应答,并能阻止PRV强毒对小鼠的侵袭。表明rPRV-PCV2d具有良好的免疫原性。
文摘传统的功率分配算法由于复杂的矩阵运算与迭代所造成的高时延,在实际通信中实时获取信道信息十分困难,当前重要的研究方向是在系统性能和计算复杂度之间找到有效平衡。针对终端直通(Device-to-Device,D2D)用户与蜂窝用户的联合功率分配问题,提出一种异构功率控制图神经网络(Heterogeneous Power Control Graph Neural Network,HPCGNN)算法,旨在最大化所有用户的加权和速率。首先通过构建干扰的异构图,将信道和噪声等信息嵌入到图的节点和边;再由HPCGNN完成消息传递和更新,采用无监督学习方式优化深度神经网络(Deep Neural Network,DNN)参数,最终得到最佳的功率分配。仿真结果表明,相较于其他深度学习算法,所提算法能够有效提高系统性能,且在损失5%性能下相较分式规划(Fractional Programming,FP)能降低82%~98%的时间复杂度。
文摘对D2D(Device to Device)通信系统的隐蔽通信问题进行研究,提出了一种基于智能反射面(Intelligent Reflecting Surfaces,IRS)的D2D通信系统,该系统采用双IRS模式。首先分析了各信号的信干噪比(SINR)和各自的期望值,并据此推导出系统遍历总容量的解形式,接着针对隐蔽通信建立了二元假设问题,推导出误检测率的解形式,并据此计算出平均最小误检测率。除此之外,还分析了无IRS系统的遍历总容量和平均最小误检测率,与双IRS系统进行对比。仿真结果表明,双IRS系统的遍历总容量和平均最小误检测率优于无IRS系统,双IRS系统能够比传统的无IRS系统获得更高的容量和更低的误检测率。
