This work uses a simple Ni-metal organic framework(Ni-MOF)to generate a uniform metal-containing carbon hybrid structure of Ni/C by in-situ pyrolysis.Then,after NaBH_(4) treatment and hydrothermal vul-canization of Ni...This work uses a simple Ni-metal organic framework(Ni-MOF)to generate a uniform metal-containing carbon hybrid structure of Ni/C by in-situ pyrolysis.Then,after NaBH_(4) treatment and hydrothermal vul-canization of Ni/C,multiphase B-doped Ni_(x)S_(y) nanoparticles can be obtained and uniformly anchored in the carbon skeleton,forming a highly porous flower-shaped B-Ni_(x)S_(y)/C composite.The positive role of B doping was theoretically confirmed by Density Function Theory(DFT)calculations.The MOF-derived car-bon framework has porous,conductive,and continuous features beneficial for fast charge transfer.There are also multiple Ni-sulfide phases in B-Ni_(x)S_(y)/C,dominated by hexagonal NiS,hexagonal Ni 2 S 3,and cu-bic Ni_(3)S_(4),which give rich valance state and are expected to bring active electrochemical reactions.In addition,the boronation process by the reducing agent of NaBH_(4) is also proved beneficial to bring high capacitance,possibly due to the incorporation of more active sites by B.Therefore,the B-Ni_(x)S_(y)/C compos-ite electrode delivers a high specific capacity of 1250.4 C g^(-1) at 1 A g^(-1) and excellent rate performance.The B-Ni_(x)S_(y)/C-based asymmetric supercapacitor also shows promising prospects for future energy stor-age devices,delivering high cyclability with capacitance retention of 87.6%after 7000 cycles.This work proves the efficiency of MOF-derived carbon framework and B-doping in improving metal sulfide’s electrochemical performances.展开更多
SINCE the discovery of high-T<sub>c</sub> superconductors, experiments have revealed that the phase diagrams of La<sub>2-x</sub>Sr<sub>x</sub>CuO<sub>4</sub> and YBa<...SINCE the discovery of high-T<sub>c</sub> superconductors, experiments have revealed that the phase diagrams of La<sub>2-x</sub>Sr<sub>x</sub>CuO<sub>4</sub> and YBa<sub>2</sub>Cu<sub>3</sub>O<sub>6+x</sub> resemble each other. The antiferromagnetic phase is commonly situated in the vicinity of the superconductive phase. In Bi-2212 sys-展开更多
Protein aggregation causes alpha-synuclein(α-syn)to change from its original physiological role to a pathological state,which is a potential pathogenic mechanism in Parkinson’s disease(PD).Chiral _(L/D)-Cu_(x)Co_(y)...Protein aggregation causes alpha-synuclein(α-syn)to change from its original physiological role to a pathological state,which is a potential pathogenic mechanism in Parkinson’s disease(PD).Chiral _(L/D)-Cu_(x)Co_(y)S supraparticles(_(L/D)-SPs)with a circular dichroism value of 35 mdeg at 805 nm were fabricated using a simple wet-chemical method.The _(L/D)-SPs prevented the α-syn monomers from forming fibrils and triggered the α-syn fibrils to turn into monomers under 808 nm near-infrared(NIR)light.In living MN9D cells,D-SPs reduced cellular damage,neuronal functional deficits,and neuron loss caused by α-syn fibrils after NIR spectroscopy treatment within 10 min to prevent α-syn aggregation.Significantly,the reactive oxygen species produced by _(D)-SPs were 1.42 times higher than those produced by _(L)-SPs.In vivo experiments showed that _(D)-SPs had a protective effect on neuron damage caused by α-syn aggregate deposition,reduced the symptoms in a mouse model of PD,and restored cognitive ability.After NIR light treatment,the amount of α-syn in a mouse model of PD decreased by more than 67.5%.At the same time,_(D)-SPs gradually decomposed into small nanoparticleswithin 60 days and were excreted through the blood-brain barrier.This discovery paves theway for the treatment of neurodegenerative diseases using chiral SPs under NIR light irradiation.展开更多
A micro fluidized bed reactor was used to study the self-sustaining catalytic combustion of carbon monoxide(CO).The Cu_(1−x)Ce_(x)O_(y) catalyst,as well as the pure CuO and CeO_(2),are used to investigate the contribu...A micro fluidized bed reactor was used to study the self-sustaining catalytic combustion of carbon monoxide(CO).The Cu_(1−x)Ce_(x)O_(y) catalyst,as well as the pure CuO and CeO_(2),are used to investigate the contributing mechanism of different active sites including dispersed CuO and Cu–Ce solid solutions.The ignition temperature(Ti)of CO over these catalysts at a flow rate of 2000 mL/min followed the order:74℃(Cu_(0.5)Ce_(0.5)O_(y))<75℃(Cu_(0.25)Ce_(0.75)O_(y))<84℃(Cu_(0.75)Ce_(0.25)O_(y))<105℃(CuO)<500℃(CeO_(2)).Furthermore,the lean combustion limits(equivalence ratioϕ)over these catalysts under the flow rates of 750–3000 mL/min(through fixed,bubbling,and fluidized bed)were also measured,which are Cu_(0.5)Ce_(0.5)O_(y)<Cu_(0.25)Ce_(0.75)Oy<Cu_(0.75)Ce_(0.25)O_(y)<CuO<CeO_(2).The fluidized bed was simulated using the Eulerian two-fluid model(TFM)coupled with a diffusion/kinetic-limited reaction model to evaluate the influence of operation conditions on the self-sustained combustion of CO.The predicted maximum temperature agreed with the experimental measurements,demonstrating the validity of the kinetic model and simulation parameters.The results of catalytic combustion with increasing CO concentrations suggest that the catalytic combustion reaction could co-exist with the flamed combustion.When a high concentration of CO is used,a blue-purple flame caused by CO combustion appears in the upper part of the fluidized bed,indicating that the range of CO-containing exhaust gas purification could be expanded to a larger range using the fluidized-bed catalytic combustion technique.展开更多
基金supported by the National Natural Science Foundations of China (No.52202317).
文摘This work uses a simple Ni-metal organic framework(Ni-MOF)to generate a uniform metal-containing carbon hybrid structure of Ni/C by in-situ pyrolysis.Then,after NaBH_(4) treatment and hydrothermal vul-canization of Ni/C,multiphase B-doped Ni_(x)S_(y) nanoparticles can be obtained and uniformly anchored in the carbon skeleton,forming a highly porous flower-shaped B-Ni_(x)S_(y)/C composite.The positive role of B doping was theoretically confirmed by Density Function Theory(DFT)calculations.The MOF-derived car-bon framework has porous,conductive,and continuous features beneficial for fast charge transfer.There are also multiple Ni-sulfide phases in B-Ni_(x)S_(y)/C,dominated by hexagonal NiS,hexagonal Ni 2 S 3,and cu-bic Ni_(3)S_(4),which give rich valance state and are expected to bring active electrochemical reactions.In addition,the boronation process by the reducing agent of NaBH_(4) is also proved beneficial to bring high capacitance,possibly due to the incorporation of more active sites by B.Therefore,the B-Ni_(x)S_(y)/C compos-ite electrode delivers a high specific capacity of 1250.4 C g^(-1) at 1 A g^(-1) and excellent rate performance.The B-Ni_(x)S_(y)/C-based asymmetric supercapacitor also shows promising prospects for future energy stor-age devices,delivering high cyclability with capacitance retention of 87.6%after 7000 cycles.This work proves the efficiency of MOF-derived carbon framework and B-doping in improving metal sulfide’s electrochemical performances.
文摘SINCE the discovery of high-T<sub>c</sub> superconductors, experiments have revealed that the phase diagrams of La<sub>2-x</sub>Sr<sub>x</sub>CuO<sub>4</sub> and YBa<sub>2</sub>Cu<sub>3</sub>O<sub>6+x</sub> resemble each other. The antiferromagnetic phase is commonly situated in the vicinity of the superconductive phase. In Bi-2212 sys-
基金financially supported by the National Natural Science Foundation of China(nos.32071400,21977038,51902136,and 21874058)the Fundamental Research Funds for the Central Universities(no.JUSRP12003).
文摘Protein aggregation causes alpha-synuclein(α-syn)to change from its original physiological role to a pathological state,which is a potential pathogenic mechanism in Parkinson’s disease(PD).Chiral _(L/D)-Cu_(x)Co_(y)S supraparticles(_(L/D)-SPs)with a circular dichroism value of 35 mdeg at 805 nm were fabricated using a simple wet-chemical method.The _(L/D)-SPs prevented the α-syn monomers from forming fibrils and triggered the α-syn fibrils to turn into monomers under 808 nm near-infrared(NIR)light.In living MN9D cells,D-SPs reduced cellular damage,neuronal functional deficits,and neuron loss caused by α-syn fibrils after NIR spectroscopy treatment within 10 min to prevent α-syn aggregation.Significantly,the reactive oxygen species produced by _(D)-SPs were 1.42 times higher than those produced by _(L)-SPs.In vivo experiments showed that _(D)-SPs had a protective effect on neuron damage caused by α-syn aggregate deposition,reduced the symptoms in a mouse model of PD,and restored cognitive ability.After NIR light treatment,the amount of α-syn in a mouse model of PD decreased by more than 67.5%.At the same time,_(D)-SPs gradually decomposed into small nanoparticleswithin 60 days and were excreted through the blood-brain barrier.This discovery paves theway for the treatment of neurodegenerative diseases using chiral SPs under NIR light irradiation.
基金support from the National Natural Science Foundation of China(No.52176141).
文摘A micro fluidized bed reactor was used to study the self-sustaining catalytic combustion of carbon monoxide(CO).The Cu_(1−x)Ce_(x)O_(y) catalyst,as well as the pure CuO and CeO_(2),are used to investigate the contributing mechanism of different active sites including dispersed CuO and Cu–Ce solid solutions.The ignition temperature(Ti)of CO over these catalysts at a flow rate of 2000 mL/min followed the order:74℃(Cu_(0.5)Ce_(0.5)O_(y))<75℃(Cu_(0.25)Ce_(0.75)O_(y))<84℃(Cu_(0.75)Ce_(0.25)O_(y))<105℃(CuO)<500℃(CeO_(2)).Furthermore,the lean combustion limits(equivalence ratioϕ)over these catalysts under the flow rates of 750–3000 mL/min(through fixed,bubbling,and fluidized bed)were also measured,which are Cu_(0.5)Ce_(0.5)O_(y)<Cu_(0.25)Ce_(0.75)Oy<Cu_(0.75)Ce_(0.25)O_(y)<CuO<CeO_(2).The fluidized bed was simulated using the Eulerian two-fluid model(TFM)coupled with a diffusion/kinetic-limited reaction model to evaluate the influence of operation conditions on the self-sustained combustion of CO.The predicted maximum temperature agreed with the experimental measurements,demonstrating the validity of the kinetic model and simulation parameters.The results of catalytic combustion with increasing CO concentrations suggest that the catalytic combustion reaction could co-exist with the flamed combustion.When a high concentration of CO is used,a blue-purple flame caused by CO combustion appears in the upper part of the fluidized bed,indicating that the range of CO-containing exhaust gas purification could be expanded to a larger range using the fluidized-bed catalytic combustion technique.
