Surface regulation is a crucial technique for improving catalytic performance in heterogeneous catalysis.Although perovskite oxides containing noble metals show good performance and excellent thermal stability,the enc...Surface regulation is a crucial technique for improving catalytic performance in heterogeneous catalysis.Although perovskite oxides containing noble metals show good performance and excellent thermal stability,the encapsulation of noble metals in perovskite lattice restricts the exposure/usage of active sites.Herein,a method of high-temperature calcination coupling with selective dissolution was adopted to tune the physicochemical environment on the LaPd_(0.1)Mn_(0.9)O_(3)catalyst surface.The X-ray diffraction(XRD)and Raman results reveal that more Pd species emerge on the surface by elevating the calcination temperature,resulting in improved catalytic toluene oxidation activity.A further acid-etching of the LPMO-900 catalyst can also boost catalytic performance,being attributed to the enhanced redox ability and abundant surface oxygen vacancies.In addition,the optimized catalyst also exhibits excellent resistance to sintering and water vapor.This study provides new avenues for the rational design of highly efficient perovskite-based catalysts.展开更多
Low cost,highly selective and efficient electrocatalysts for CO_(2)reduction reaction(CO_(2)RR)is crucial for lowering the global carbon footprint and mitigating energy shortages.Here,we first report a highly selectiv...Low cost,highly selective and efficient electrocatalysts for CO_(2)reduction reaction(CO_(2)RR)is crucial for lowering the global carbon footprint and mitigating energy shortages.Here,we first report a highly selective and efficient electrocatalyst for CO_(2)RR to CO using a surface-regulated Ni nanoparticles supported on N-doped CMK-3(N,O-Ni/CMK3).Compared with most Ni metal catalysts previously reported with severe competitive hydrogen evolution during the CO_(2)RR,the N,O-Ni/CMK3 catalyst presents a superior CO faradaic efficiency of about 97%,a high CO partial current density(13.01 mA cm^(-1))and turnover frequency(4.25 s^(–1)).The comprehensive characterization provides evidence that the N,O co-regulated Ni acts as the active center.Taking advantage of the N,O co-regulated chemical environment,N,O-Ni/CMK3 also displays a decent stability at negative potentials.Our work paves a novel approach for developing transition metal catalysts for CO_(2)RR with enhanced activity and selectivity via regulating surface chemical environment.展开更多
Although Pt Ni catalyst possesses good oxygen reduction activity,its poor stability is the main obstacle for the commercialization of proton exchange membrane fuel cells(PEMFCs).In this work,we introduce the acid-resi...Although Pt Ni catalyst possesses good oxygen reduction activity,its poor stability is the main obstacle for the commercialization of proton exchange membrane fuel cells(PEMFCs).In this work,we introduce the acid-resistant refractory Mo to enhance the structure stability and modify the electronic structure of Pt in the prepared PtNi catalyst,improving the catalytic activity for oxygen reduction reaction(ORR).In addition,near-surface Pt content in the nanoparticle is also optimized to balance the ORR activity and stability.The electrochemical results show that the alloy formed by Mo and Pt Ni is obviously more stable than the PtNi alloy alone,because the acid-resistant Mo and its oxides effectively prevent the dissolution of Pt.Especially,the Pt3 Ni3 MoN/C exhibits the optimal ORR catalytic performance in O2-saturated 0.1 mol L^(-1)HClO4 aqueous solutions,with mass activity(MA)of 900 m A mg^(-1)Pt at 0.90 V vs.RHE,which is 3.75 times enhancement compared with the commercial Pt/C(240 mA mg^(-1)Pt).After 30 k accelerated durability tests,its MA(690 m A mg^(-1)Pt)is still 2.88 times higher than the pristine Pt/C.This study thus provides a valuable method to design stable ORR catalysts with high efficiency and has great significance for the commercialization of PEMFCs.展开更多
Aqueous zinc-air battery(ZAB)has attractive features as the potential energy storage system such as high safety,low cost and good environmental compatibility.However,the issue of dendrite growth on zinc metal anodes h...Aqueous zinc-air battery(ZAB)has attractive features as the potential energy storage system such as high safety,low cost and good environmental compatibility.However,the issue of dendrite growth on zinc metal anodes has seriously hindered the development of ZAB.Herein,the N-doped carbon cloth(NC)prepared via magnetron sputtering is explored as the substrate to induce the uniform nucleation of zinc metal and suppress dendrite growth.Results show that the introduction of heteroatoms accelerates the migration and deposition kinetics of Zn^(2+)by boosting the desolvation process of Zn^(2+),eventually reducing the nucleation overpotential.Besides,theoretical calculation results confirm the zincophilicity of N-containing functional group(such as pyridine N and pyrrole N),which can guide the nucleation and growth of zinc uniformly on the electrode surface by both promoting the redistribution of Zn^(2+) in the vicinity of the surface and enhancing its interaction with zinc atoms.As a result,the half-cell assembled with magnetron sputtered carbon cloth achieves a high zinc stripping/plating coulombic efficiency of 98.8%and long-term stability of over 500 cycles at 0.2 mA cm^(-2).And the Coulombic efficiency reached about 99.5%at the 10th cycle and maintained for more than 210 cycles at a high current density of 5.0 mA cm^(-2).The assembled symmetrical battery can deliver 220 plating/stripping cycles with ultra-low voltage hysteresis of only 11 mV.In addition,the assembled zinc-air full battery with NC-Zn anode delivers a high special capacity of about 429 mAh g_(Zn)^(-1) and a long life of over 430 cycles.The effectiveness of surface functionalization in promoting the transfer and deposition kinetics of Zn^(2+) presented in this work shows enlightening significance in the development of metal anodes in aqueous electrolytes.展开更多
The regulation and spatial differences of urban runoffs are of great concern in contemporary hydrological research.However,owing to a shortage of basic data sources and restrictions on urban hydrological simulation fu...The regulation and spatial differences of urban runoffs are of great concern in contemporary hydrological research.However,owing to a shortage of basic data sources and restrictions on urban hydrological simulation functions,simulating and investigating the regulation mechanism behind rainfall-runoff processes remain significantly challenging.In this study,the Time Variant Gain Model(TVGM),a hydrological nonlinear system model,was extrapolated to the hydrodynamic model of an urban drainage network system by integrating it with the widely used Stormwater Management Model(SWMM)to adequately simulate urban runoff events while considering various underlying surfaces and runoff routing modes,such as surface,drainage network and river runoff,in urban regions(i.e.,TVGM-SWMM).Moreover,runoff events were characterized using the following four runoff regime metrics:runoff coefficient,capture ratio of annual runoff volume,standardized flood timescale,and the ratio of occurrence time differences between flow and rainfall peak to event duration(peak flow delay time).The characteristics and spatial differences of urban runoff regulations were investigated,and the key impact factors and their relative contributions were identified using multivariate statistical analyses.Four communities were selected as our study areas,consisting of communities from Beijing,Shenzhen,Wuhan,and Chongqing.Our results showed that the TVGM-SWMM performed considerably better than SWMM alone.The comprehensive simulation accuracy of 60%of the events(12/20)improved by 4-86%,with the bias improving the most,followed by the efficiency coefficient.Barring the runoff coefficient,significant spatial differences were identified at the patch scale for the runoff regime metrics,with differences of 0.43,0.22,and 0.16(p<0.05).The key impact factors were the pipe length(r=0.51)in the drainage network system and the forest area ratios(r=0.56),sponge measures(r=0.52),grassland(r=0.48),and impervious surface(r=0.46)in the underlying surfaces.The contributions of the drainage network system and the underlying surfaces were 4.27%and 37.83%,respectively.Regulation in the Beijing community,dominated by grassland regulation,delayed and reduced the peak flow and total runoff volume.In the Shenzhen community,sharp and thin runoff events were mainly generated by impervious surfaces and were not adequately regulated.Forest regulation was the dominant regulation type in the Wuhan community,which reduced the total runoff volume and delayed the peak flow.Waterbody regulation was the primary regulation type in the Chongqing community,which reduced the total runoff volume and peak flow.This study aims to introduce a comprehensive theoretical and technical assessment of the hydrological effects of urbanization and the performance of sponge city construction and provide a reference for urban hydrological model improvements in China.展开更多
One major challenge of using DNA nanostructures for cellular and in vivo applications is their insufficiently structural integrity that stems from the non-covalent base pairing and stacking in complex cellular and phy...One major challenge of using DNA nanostructures for cellular and in vivo applications is their insufficiently structural integrity that stems from the non-covalent base pairing and stacking in complex cellular and physiological environment. The establishment of covalent bonds in DNA nanostructures can link individual strands more stably and therefore should improve the performance of DNA nanostructures in different scenarios where structural integrity is required. Here, we developed a convenient and effective method for constructing covalently stabilized DNA nanostructures by chemically inserting photo-crosslinker(^(CNV)K) in DNA sequences. These covalently linked DNA nanostructures were found to be more resistant to external interference, such as low cation concentrations and unspecific displacement on cell membranes. We also demonstrated that our strategy could improve the efficiency of cell surface receptor-mediated labeling and function regulations in living cells, which sheds light on broadening the biomedical applications of DNA nanostructures.展开更多
Silver chalcogenides(Ag_(2)E;E=S,Se,or Te)quantum dots(QDs)have emerged as promising candidates for near-infrared(NIR)applications.However,their narrow bandgap and small exciton Bohr radius render the optical properti...Silver chalcogenides(Ag_(2)E;E=S,Se,or Te)quantum dots(QDs)have emerged as promising candidates for near-infrared(NIR)applications.However,their narrow bandgap and small exciton Bohr radius render the optical properties of Ag_(2)E QDs highly sensitive to surface and size variations.Moreover,the propensity for the formation of silver impurities and their low solubility product constants pose challenges in their controllable synthesis.Recent advancements have deepened our understanding of the relationship between the multi-hierarchical structure of Ag_(2)E QDs and their optical properties.Through rational design and precise structural regulation,the performance of Ag_(2)E QDs has been significantly enhanced across various applications.This review provides a comprehensive overview of historical and current progress in the synthesis and structural regulation of Ag_(2)E QDs,encompassing aspects such as size control,crystal structure engineering,and surface/interface engineering.Additionally,it discusses outstanding challenges and potential opportunities in this field.The aim of this review is to promote the custom synthesis of Ag_(2)E QDs for applications in biological imaging,and optoelectronics applications.展开更多
This paper presents LQR sliding surface-based Sliding Mode Controller(LQR-SMC)for balancing control of a Rotary Double Inverted Pendulum(RDIP)system.It is a challenging research topic in control engineering due to its...This paper presents LQR sliding surface-based Sliding Mode Controller(LQR-SMC)for balancing control of a Rotary Double Inverted Pendulum(RDIP)system.It is a challenging research topic in control engineering due to its nonlinearity and instability.The RDIP system uses only a motor to control two serially connected pendulums to stand at the upright position.The sliding surface is designed based on the LQR optimal gain.Nonsingular gain matrix is obtained by using the left inverse of the input matrix in the state space form of the system dynamics.The Lyapunov stability theory is used to determine the stability of the controller.To evaluate the performance of LQR-SMC,some performance indices,including the Integral Absolute Error(IAE),Integral Time Absolute Error(ITAE),and the Integrated Square Error(ISE),are used.System stability can be maintained by LQR-SMC under external disturbances as well as model and parameter uncertainties.展开更多
基金Project supported by the National Key R&D Program of China(2023YFC3710300)the National Natural Science Foundation of China(U23A2099,22276111)+1 种基金the Taishan Scholar Project of Shandong Province(202306031)the Natural Science Foundation of Shandong Province(2023HWYQ-024)。
文摘Surface regulation is a crucial technique for improving catalytic performance in heterogeneous catalysis.Although perovskite oxides containing noble metals show good performance and excellent thermal stability,the encapsulation of noble metals in perovskite lattice restricts the exposure/usage of active sites.Herein,a method of high-temperature calcination coupling with selective dissolution was adopted to tune the physicochemical environment on the LaPd_(0.1)Mn_(0.9)O_(3)catalyst surface.The X-ray diffraction(XRD)and Raman results reveal that more Pd species emerge on the surface by elevating the calcination temperature,resulting in improved catalytic toluene oxidation activity.A further acid-etching of the LPMO-900 catalyst can also boost catalytic performance,being attributed to the enhanced redox ability and abundant surface oxygen vacancies.In addition,the optimized catalyst also exhibits excellent resistance to sintering and water vapor.This study provides new avenues for the rational design of highly efficient perovskite-based catalysts.
文摘Low cost,highly selective and efficient electrocatalysts for CO_(2)reduction reaction(CO_(2)RR)is crucial for lowering the global carbon footprint and mitigating energy shortages.Here,we first report a highly selective and efficient electrocatalyst for CO_(2)RR to CO using a surface-regulated Ni nanoparticles supported on N-doped CMK-3(N,O-Ni/CMK3).Compared with most Ni metal catalysts previously reported with severe competitive hydrogen evolution during the CO_(2)RR,the N,O-Ni/CMK3 catalyst presents a superior CO faradaic efficiency of about 97%,a high CO partial current density(13.01 mA cm^(-1))and turnover frequency(4.25 s^(–1)).The comprehensive characterization provides evidence that the N,O co-regulated Ni acts as the active center.Taking advantage of the N,O co-regulated chemical environment,N,O-Ni/CMK3 also displays a decent stability at negative potentials.Our work paves a novel approach for developing transition metal catalysts for CO_(2)RR with enhanced activity and selectivity via regulating surface chemical environment.
基金supported by the National Natural Science Foundation of China(21872040)the Natural Science Foundation of Guangxi(2016GXNSFCB380002)+1 种基金the Hundred Talents Program of Guangxi Universitiesthe Excellence Scholars and Innovation Team of Guangxi Universities。
文摘Although Pt Ni catalyst possesses good oxygen reduction activity,its poor stability is the main obstacle for the commercialization of proton exchange membrane fuel cells(PEMFCs).In this work,we introduce the acid-resistant refractory Mo to enhance the structure stability and modify the electronic structure of Pt in the prepared PtNi catalyst,improving the catalytic activity for oxygen reduction reaction(ORR).In addition,near-surface Pt content in the nanoparticle is also optimized to balance the ORR activity and stability.The electrochemical results show that the alloy formed by Mo and Pt Ni is obviously more stable than the PtNi alloy alone,because the acid-resistant Mo and its oxides effectively prevent the dissolution of Pt.Especially,the Pt3 Ni3 MoN/C exhibits the optimal ORR catalytic performance in O2-saturated 0.1 mol L^(-1)HClO4 aqueous solutions,with mass activity(MA)of 900 m A mg^(-1)Pt at 0.90 V vs.RHE,which is 3.75 times enhancement compared with the commercial Pt/C(240 mA mg^(-1)Pt).After 30 k accelerated durability tests,its MA(690 m A mg^(-1)Pt)is still 2.88 times higher than the pristine Pt/C.This study thus provides a valuable method to design stable ORR catalysts with high efficiency and has great significance for the commercialization of PEMFCs.
基金supported by the National Natural Science Foundation of China(Grant No.21905033)the Science and Technology Department of Sichuan Province(Grant No.2019YJ0503)State Key Laboratory of Vanadium and Titanium Resources Comprehensive Utilization(2020P4FZG02A).
文摘Aqueous zinc-air battery(ZAB)has attractive features as the potential energy storage system such as high safety,low cost and good environmental compatibility.However,the issue of dendrite growth on zinc metal anodes has seriously hindered the development of ZAB.Herein,the N-doped carbon cloth(NC)prepared via magnetron sputtering is explored as the substrate to induce the uniform nucleation of zinc metal and suppress dendrite growth.Results show that the introduction of heteroatoms accelerates the migration and deposition kinetics of Zn^(2+)by boosting the desolvation process of Zn^(2+),eventually reducing the nucleation overpotential.Besides,theoretical calculation results confirm the zincophilicity of N-containing functional group(such as pyridine N and pyrrole N),which can guide the nucleation and growth of zinc uniformly on the electrode surface by both promoting the redistribution of Zn^(2+) in the vicinity of the surface and enhancing its interaction with zinc atoms.As a result,the half-cell assembled with magnetron sputtered carbon cloth achieves a high zinc stripping/plating coulombic efficiency of 98.8%and long-term stability of over 500 cycles at 0.2 mA cm^(-2).And the Coulombic efficiency reached about 99.5%at the 10th cycle and maintained for more than 210 cycles at a high current density of 5.0 mA cm^(-2).The assembled symmetrical battery can deliver 220 plating/stripping cycles with ultra-low voltage hysteresis of only 11 mV.In addition,the assembled zinc-air full battery with NC-Zn anode delivers a high special capacity of about 429 mAh g_(Zn)^(-1) and a long life of over 430 cycles.The effectiveness of surface functionalization in promoting the transfer and deposition kinetics of Zn^(2+) presented in this work shows enlightening significance in the development of metal anodes in aqueous electrolytes.
基金supported by the Subproject of Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA23040301)the National Natural Science Foundation of China(Grant No.42071041)。
文摘The regulation and spatial differences of urban runoffs are of great concern in contemporary hydrological research.However,owing to a shortage of basic data sources and restrictions on urban hydrological simulation functions,simulating and investigating the regulation mechanism behind rainfall-runoff processes remain significantly challenging.In this study,the Time Variant Gain Model(TVGM),a hydrological nonlinear system model,was extrapolated to the hydrodynamic model of an urban drainage network system by integrating it with the widely used Stormwater Management Model(SWMM)to adequately simulate urban runoff events while considering various underlying surfaces and runoff routing modes,such as surface,drainage network and river runoff,in urban regions(i.e.,TVGM-SWMM).Moreover,runoff events were characterized using the following four runoff regime metrics:runoff coefficient,capture ratio of annual runoff volume,standardized flood timescale,and the ratio of occurrence time differences between flow and rainfall peak to event duration(peak flow delay time).The characteristics and spatial differences of urban runoff regulations were investigated,and the key impact factors and their relative contributions were identified using multivariate statistical analyses.Four communities were selected as our study areas,consisting of communities from Beijing,Shenzhen,Wuhan,and Chongqing.Our results showed that the TVGM-SWMM performed considerably better than SWMM alone.The comprehensive simulation accuracy of 60%of the events(12/20)improved by 4-86%,with the bias improving the most,followed by the efficiency coefficient.Barring the runoff coefficient,significant spatial differences were identified at the patch scale for the runoff regime metrics,with differences of 0.43,0.22,and 0.16(p<0.05).The key impact factors were the pipe length(r=0.51)in the drainage network system and the forest area ratios(r=0.56),sponge measures(r=0.52),grassland(r=0.48),and impervious surface(r=0.46)in the underlying surfaces.The contributions of the drainage network system and the underlying surfaces were 4.27%and 37.83%,respectively.Regulation in the Beijing community,dominated by grassland regulation,delayed and reduced the peak flow and total runoff volume.In the Shenzhen community,sharp and thin runoff events were mainly generated by impervious surfaces and were not adequately regulated.Forest regulation was the dominant regulation type in the Wuhan community,which reduced the total runoff volume and delayed the peak flow.Waterbody regulation was the primary regulation type in the Chongqing community,which reduced the total runoff volume and peak flow.This study aims to introduce a comprehensive theoretical and technical assessment of the hydrological effects of urbanization and the performance of sponge city construction and provide a reference for urban hydrological model improvements in China.
基金supported by the National Key Research and Development Program of China (2021YFA0909400)the National Natural Science Foundation of China (21974087, 81974315)+6 种基金Shanghai Municipal Education Commission-Gaofeng Clinical Medicine Grant Support (20181709)Shanghai Rising-Star Program (20QA1405800)the General Projects of China Postdoctoral Fund (2021M692104)Innovative Research Team of High-Level Local Universities in Shanghaifaculty start-up funding support from the Institute of Molecular Medicine of Shanghai Jiao Tong UniversityRecruitment Program of Global Youth Experts of China。
文摘One major challenge of using DNA nanostructures for cellular and in vivo applications is their insufficiently structural integrity that stems from the non-covalent base pairing and stacking in complex cellular and physiological environment. The establishment of covalent bonds in DNA nanostructures can link individual strands more stably and therefore should improve the performance of DNA nanostructures in different scenarios where structural integrity is required. Here, we developed a convenient and effective method for constructing covalently stabilized DNA nanostructures by chemically inserting photo-crosslinker(^(CNV)K) in DNA sequences. These covalently linked DNA nanostructures were found to be more resistant to external interference, such as low cation concentrations and unspecific displacement on cell membranes. We also demonstrated that our strategy could improve the efficiency of cell surface receptor-mediated labeling and function regulations in living cells, which sheds light on broadening the biomedical applications of DNA nanostructures.
基金supported by the National Natural Science Foundation of China(Nos.22293030 and 22293032)the China Postdoctoral Science Foundation(No.2022M721697).
文摘Silver chalcogenides(Ag_(2)E;E=S,Se,or Te)quantum dots(QDs)have emerged as promising candidates for near-infrared(NIR)applications.However,their narrow bandgap and small exciton Bohr radius render the optical properties of Ag_(2)E QDs highly sensitive to surface and size variations.Moreover,the propensity for the formation of silver impurities and their low solubility product constants pose challenges in their controllable synthesis.Recent advancements have deepened our understanding of the relationship between the multi-hierarchical structure of Ag_(2)E QDs and their optical properties.Through rational design and precise structural regulation,the performance of Ag_(2)E QDs has been significantly enhanced across various applications.This review provides a comprehensive overview of historical and current progress in the synthesis and structural regulation of Ag_(2)E QDs,encompassing aspects such as size control,crystal structure engineering,and surface/interface engineering.Additionally,it discusses outstanding challenges and potential opportunities in this field.The aim of this review is to promote the custom synthesis of Ag_(2)E QDs for applications in biological imaging,and optoelectronics applications.
文摘This paper presents LQR sliding surface-based Sliding Mode Controller(LQR-SMC)for balancing control of a Rotary Double Inverted Pendulum(RDIP)system.It is a challenging research topic in control engineering due to its nonlinearity and instability.The RDIP system uses only a motor to control two serially connected pendulums to stand at the upright position.The sliding surface is designed based on the LQR optimal gain.Nonsingular gain matrix is obtained by using the left inverse of the input matrix in the state space form of the system dynamics.The Lyapunov stability theory is used to determine the stability of the controller.To evaluate the performance of LQR-SMC,some performance indices,including the Integral Absolute Error(IAE),Integral Time Absolute Error(ITAE),and the Integrated Square Error(ISE),are used.System stability can be maintained by LQR-SMC under external disturbances as well as model and parameter uncertainties.
