The irreversible oxygen redox(OR)in Li-rich layered cathodes leads to severe structural degradation and voltage decay,particularly under harsh operating conditions.Although high-entropy oxides(HEOs)offer enhanced stab...The irreversible oxygen redox(OR)in Li-rich layered cathodes leads to severe structural degradation and voltage decay,particularly under harsh operating conditions.Although high-entropy oxides(HEOs)offer enhanced stability compared to conventional doping modifications,rational element selection for optimizing OR reversibility remains unexplored.Here,we propose an entropy engineering design paradigm for “oxygen-anchoring”,where optimal cation electronegativity(>Mn,1.55)and d(3d/4d)-p orbital hybridization synergistically enhance transition metal–oxygen(TM–O)covalency and stabilize the O2p state.Two high-entropy Li-rich layered oxides:Li_(1.2)Mn_(0.47)Ni_(0.115)Co_(0.115)Mg_(0.02)Ti_(0.02)Al_(0.02)Nb_(0.02)Mo_(0.02)O_(2)(MTANM)and Li_(1.2)Mn_(0.47)Ni_(0.115)Co_(0.115)Mg_(0.02)Ti_(0.02)Cu_(0.02)Nb_(0.02)Mo_(0.02)O_(2)(MTCNM)were synthesized using partial nano-scale precursors and comparatively evaluated.MTCNM exhibits enhanced electrochemical performance and superior oxygen stability compared to MTANM by replacing Al with higher-electronegativity Cu,which possesses improved orbital overlap with oxygen.Both experiments and density functional theory(DFT)calculations demonstrate that element selection changes the covalency of TM–O through altered electronegativity and d orbitals-p orbitals(d-p)hybridization.Further stepwise screening selected the optimal elemental combination Li_(1.2)Mn_(0.47)Ni_(0.115)Co_(0.115)Cr_(0.02)Cu_(0.02)Nb_(0.02)Mo_(0.02)Ru_(0.02)O_(2)(CCNMR),which achieved near 100%capacity retention after 150 cycles at 1 C,50℃,with its voltage decay effectively suppressed.This work establishes a rational element-screening paradigm for entropy-stabilized OR chemistry in high-energy cathodes.展开更多
Hydroxyl radical(·OH)formation from Fe(Ⅱ)-bearing clay mineral oxygenation in the shallow subsurface has been well documented under moderate environmental conditions.However,the impact of freezing processes on t...Hydroxyl radical(·OH)formation from Fe(Ⅱ)-bearing clay mineral oxygenation in the shallow subsurface has been well documented under moderate environmental conditions.However,the impact of freezing processes on the·OH production capability of Fe(Ⅱ)-bearing clay minerals for organic contaminant degradation,particularly in seasonally frozen soils,remains unclear.In this study,we investigated the influence of pre-freezing durations on the mineral proprieties,·OH production,and phenol degradation during the oxygenation of reduced Fe-rich nontronite(rNAu-2)and Fe-poor montmorillonite(rSWy-3).During the freezing process of reduced clay minerals(1 mM Fe(Ⅱ)),the content of edge surface Fe and Fe(Ⅱ)decreased by up to 46%and 58%,respectively,followed by a slight increased as clay mineral particles aggregated and subsequently partially disaggregated.As the edge surface Fe(Ⅱ)is effective in O_(2) activation but less effective in the transformation of H_(2)O_(2) to·OH,the redistribution of edge surface Fe(Ⅱ)leads to that·OH production and phenol degradation increased initially and then decreased with pre-freezing durations ranging from 0 to 20 days.Moreover,the rate constants of phenol degradation for both the rapid and slow reaction phases also first increase and then decrease with freezing time.However,pre-freezing significantly influenced the rapid phase of phenol degradation by rNAu-2 but affected the slow phase by rSWy-3 due to the much higher edge-surface Fe(Ⅱ)content in rNAu-2.Overall,these findings provide novel insights into the mechanism of·OH production and contaminant degradation during the freeze-thaw processes in clay-rich soils.展开更多
Rapid formation of a continuous endothelial cell(EC)monolayer with healthy endothelium function on the luminal surface of vascular implants is imperative to improve the longtime patency of small-diameter vascular impl...Rapid formation of a continuous endothelial cell(EC)monolayer with healthy endothelium function on the luminal surface of vascular implants is imperative to improve the longtime patency of small-diameter vascular implants.In the present study,we combined the contact guidance effects of aligned nanofibers,which enhance EC adhesion and proliferation because of its similar fiber scale with native vascular basement membranes,and aligned microfibers,which could induce EC elongation effectively and allow ECs infiltration.It was followed by successive immobilization of collagen IV and laminin to fabricate a biomimetic basement membrane(BBM)with structural and compositional biomimicry.The hemolysis assay and platelet adhesion results showed that the BBM exhibited excellent hemocompatibility.Meanwhile,the adhered human umbilical vein endothelial cells(HUVECs)onto theBBMaligned along the orientation of the microfibers with an elongated morphology,and the data demonstrated that the BBM showed favorable effects on EC attachment,proliferation,and viability.The oriented EC monolayer formed on the BBM exhibited improved antithrombotic capability as indicated by higher production of nitric oxide and prostacyclin(PGI2).Furthermore,fluorescence images indicated that HUVECs could infiltrate into the BBM,implying theBBM’s ability to enhance transmural endothelialization.Hence,theBBMpossessed the properties to regulate ECbehaviors and allow transmural ingrowth,demonstrating the potential to be applied as the luminal surface of small-diameter vascular implants for rapid endothelialization.展开更多
The development of efficient Cu-based heterogeneous catalysts for CO_(2) hydrogenation to methanol has been an appealing subject.Inspired by the concept of inverse catalysts,a series of La_(2)O_(2)CO_(3)/Cu nanorod co...The development of efficient Cu-based heterogeneous catalysts for CO_(2) hydrogenation to methanol has been an appealing subject.Inspired by the concept of inverse catalysts,a series of La_(2)O_(2)CO_(3)/Cu nanorod composites with varying Cu contents(denoted as LOC/Cu-x,where x stands for the mass ratio of La and Cu in the catalysts)were prepared by combining coprecipitation and calcination processes.Remarkable composition-dependence of catalytic activity and selectivity were observed when different LOC/Cu-x(x=0.1,0.2,0.5,1,3 and 5)were used to catalyze the CO_(2) hydrogenation.The predominant product shifted from methane to methanol with the increasing Cu content.The highest reaction rate(13.3 mmol·gCu^(-1)·h^(-1))and methanol selectivity(85.5%)were achieved when LOC/Cu-1 was tested at 200℃.The LOC was not active for the reaction,while the Cu itself displayed poor catalytic performance.The Cu–LOC interactions significantly affected the nature of the catalysts,including mutual electron transfer,crystal structure,morphology,porosity,surface Cu valence and capability of adsorbing the reactant gases,etc.,which account for the outstanding behavior of the LOC/Cu-1 catalyst.This work provides a new strategy for the design and optimization of Cu-based catalysts.展开更多
Biomass is considered a renewable and cleaner energy source alternative to fossil fuels.In recent years,industrial biomass boilers have been rapidly developed and widely used in the industrial field.This work makes a ...Biomass is considered a renewable and cleaner energy source alternative to fossil fuels.In recent years,industrial biomass boilers have been rapidly developed and widely used in the industrial field.This work makes a review on the fuel types used in industrial biomass boilers,the fuel characteristics and the characteristics of air pollutants emitted from the combustion of industrial biomass boilers and other contents in different studies.However,the existing research still has many deficiencies.In the future,further research on biomass fuel,industrial biomass boiler combustion process and the pollutants emitted by industrial biomass boiler combustion,especially the carbonaceous aerosol emitted by in-dustrial biomass boiler and carbonaceous aerosol optical properties still need to be made.At the same time,the potential harm of carbonaceous aerosols emitted from industrial biomass boiler sources to human health and climate change needs to be studied in depth.This review provides a scientific basis for the accurate evaluation of industrial biomass boilers and the effective prevention and control of various pollutants of industrial biomass boilers.展开更多
Recent progress in bioresorbable stents(BRSs)has provided a promising alternative for treating coronary artery disease.However,there is still lack of BRSs with satisfied compression and degradation performance for ped...Recent progress in bioresorbable stents(BRSs)has provided a promising alternative for treating coronary artery disease.However,there is still lack of BRSs with satisfied compression and degradation performance for pediatric patients with congenital heart disease,leading to suboptimal therapy effects.Here,we developed a mechanically self-reinforced composite bioresorbable stent(cBRS)for congenital heart disease application.The cBRS consisted of poly(p-dioxanone)monofilaments and polycaprolactone/poly(p-dioxanone)core-shell composite yarns.Interlacing points in cBRS structure were partially bonded,offering the cBRS with significantly higher compression force compared to typical braids and remained good compliance.The suitable degradation profile of the cBRS can possibly preserve vascular remodeling and healing process.In addition,the controllable structural organization provides a method to customize the performance of the cBRS by altering the proportion of different components in the braids.The in vivo results suggested the cBRS supported the vessel wall similar to that of metallic stent.In both abdominal aorta and iliac artery of porcine,cBRS was entirely endothelialized within 1 month and maintained target vessels with good patency in the 12-month follow-up.The in vivo degradation profile of the cBRS is consistent with static degradation results in vitro.It is also demonstrated that there is minimal impact of pulsatile pressure of blood flow and variation of radial force on the degradation rate of the cBRS.Moreover,the lumen of cBRS implanted vessels were enlarged after 6 months,and significantly larger than the vessels implanted with metallic stent in 12 months.展开更多
Fe3O4 nano-whiskers were synthesized via ultrasonic-aided reduction of FeCl2.4H2O with N2H4-H2O in concentrated NaOH solution. Phase identification and morphology observation were conducted by X-ray diffraction （XRD...Fe3O4 nano-whiskers were synthesized via ultrasonic-aided reduction of FeCl2.4H2O with N2H4-H2O in concentrated NaOH solution. Phase identification and morphology observation were conducted by X-ray diffraction （XRD） analysis, transmission electron microscopy （TEM） and field emission scanning electron microscopy （FE-SEM）. Face scanning energy dispersive spectrum （face scanning EDS） and twodimensional fast Fourier transform （2DFFF） for element distribution were carried out for confirming composition homogeneity. From XRD and TEIVI, the synthesized Fe304 nano-whiskers are of cubic phase with average dimension of 20 nm~ 200 nm （average aspect ratio of 10）. FE-SEM shows that the nanowhiskers without dispersion are interconnected into a network at a scale of 20μm. 2DFFT of the distribution of Fe and O from face scanning EDS confirms the composition homogeneity of the synthesized Fe3O4. Hydrazine hydrate determines the formation of the nano-whiskers, while the possible mechanism is the preferred growth along certain orientation with the aid of ultrasonic treatment.展开更多
Recent advances in fluorescence microscopy have provided researchers with powerful new tools to visualize cellular processes occurring in real time, giving researchers an unprecedented opportunity to address many biol...Recent advances in fluorescence microscopy have provided researchers with powerful new tools to visualize cellular processes occurring in real time, giving researchers an unprecedented opportunity to address many biological questions that were previously inaccessible. With respect to neurobiology, these real-time imaging techniques have deepened our understanding of molecular and cellular processes, including the movement and dynamics of single proteins and organelles in living cells. In this review, we summarize recent advances in the field of real-time imaging of single synaptic vesicles in live neurons.展开更多
基金financially supported by the National Natural Science Foundation of China(no.52172209)the Shenzhen International Cooperative Research Project(GJHZ20240218113607014)。
文摘The irreversible oxygen redox(OR)in Li-rich layered cathodes leads to severe structural degradation and voltage decay,particularly under harsh operating conditions.Although high-entropy oxides(HEOs)offer enhanced stability compared to conventional doping modifications,rational element selection for optimizing OR reversibility remains unexplored.Here,we propose an entropy engineering design paradigm for “oxygen-anchoring”,where optimal cation electronegativity(>Mn,1.55)and d(3d/4d)-p orbital hybridization synergistically enhance transition metal–oxygen(TM–O)covalency and stabilize the O2p state.Two high-entropy Li-rich layered oxides:Li_(1.2)Mn_(0.47)Ni_(0.115)Co_(0.115)Mg_(0.02)Ti_(0.02)Al_(0.02)Nb_(0.02)Mo_(0.02)O_(2)(MTANM)and Li_(1.2)Mn_(0.47)Ni_(0.115)Co_(0.115)Mg_(0.02)Ti_(0.02)Cu_(0.02)Nb_(0.02)Mo_(0.02)O_(2)(MTCNM)were synthesized using partial nano-scale precursors and comparatively evaluated.MTCNM exhibits enhanced electrochemical performance and superior oxygen stability compared to MTANM by replacing Al with higher-electronegativity Cu,which possesses improved orbital overlap with oxygen.Both experiments and density functional theory(DFT)calculations demonstrate that element selection changes the covalency of TM–O through altered electronegativity and d orbitals-p orbitals(d-p)hybridization.Further stepwise screening selected the optimal elemental combination Li_(1.2)Mn_(0.47)Ni_(0.115)Co_(0.115)Cr_(0.02)Cu_(0.02)Nb_(0.02)Mo_(0.02)Ru_(0.02)O_(2)(CCNMR),which achieved near 100%capacity retention after 150 cycles at 1 C,50℃,with its voltage decay effectively suppressed.This work establishes a rational element-screening paradigm for entropy-stabilized OR chemistry in high-energy cathodes.
基金supported by the National Natural Science Foundation of China(Nos.U22A20591,42077185,42107217)the Sichuan Province Science and Technology Program for Distinguished Young Scholars(No.2022JDJQ0010)+1 种基金the Sichuan Science and Technology Program(No.2024NSFSC0842)the State Key Laboratory of Geohazard Prevention and Geoenvironment Protection(No.SKLGP2020Z002)。
文摘Hydroxyl radical(·OH)formation from Fe(Ⅱ)-bearing clay mineral oxygenation in the shallow subsurface has been well documented under moderate environmental conditions.However,the impact of freezing processes on the·OH production capability of Fe(Ⅱ)-bearing clay minerals for organic contaminant degradation,particularly in seasonally frozen soils,remains unclear.In this study,we investigated the influence of pre-freezing durations on the mineral proprieties,·OH production,and phenol degradation during the oxygenation of reduced Fe-rich nontronite(rNAu-2)and Fe-poor montmorillonite(rSWy-3).During the freezing process of reduced clay minerals(1 mM Fe(Ⅱ)),the content of edge surface Fe and Fe(Ⅱ)decreased by up to 46%and 58%,respectively,followed by a slight increased as clay mineral particles aggregated and subsequently partially disaggregated.As the edge surface Fe(Ⅱ)is effective in O_(2) activation but less effective in the transformation of H_(2)O_(2) to·OH,the redistribution of edge surface Fe(Ⅱ)leads to that·OH production and phenol degradation increased initially and then decreased with pre-freezing durations ranging from 0 to 20 days.Moreover,the rate constants of phenol degradation for both the rapid and slow reaction phases also first increase and then decrease with freezing time.However,pre-freezing significantly influenced the rapid phase of phenol degradation by rNAu-2 but affected the slow phase by rSWy-3 due to the much higher edge-surface Fe(Ⅱ)content in rNAu-2.Overall,these findings provide novel insights into the mechanism of·OH production and contaminant degradation during the freeze-thaw processes in clay-rich soils.
基金This work was supported by the Fundamental Research Funds for the Central Universities(Nos.2232019G-06 and 2232019A3-06)111 project(No.PB0719035)+1 种基金The authors at University of Wisconsin-Madison would like to acknowledge the partial support by the Wisconsin Institute for Discovery(WID),the NHLBI of the National Institutes of Health(No.U01HL134655)the Kuo K.and Cindy F.Wang Professorship.Chenglong Yu also acknowledged the fellowship from the China Scholarship Council(CSC)under the Grant CSC No.201906630070.
文摘Rapid formation of a continuous endothelial cell(EC)monolayer with healthy endothelium function on the luminal surface of vascular implants is imperative to improve the longtime patency of small-diameter vascular implants.In the present study,we combined the contact guidance effects of aligned nanofibers,which enhance EC adhesion and proliferation because of its similar fiber scale with native vascular basement membranes,and aligned microfibers,which could induce EC elongation effectively and allow ECs infiltration.It was followed by successive immobilization of collagen IV and laminin to fabricate a biomimetic basement membrane(BBM)with structural and compositional biomimicry.The hemolysis assay and platelet adhesion results showed that the BBM exhibited excellent hemocompatibility.Meanwhile,the adhered human umbilical vein endothelial cells(HUVECs)onto theBBMaligned along the orientation of the microfibers with an elongated morphology,and the data demonstrated that the BBM showed favorable effects on EC attachment,proliferation,and viability.The oriented EC monolayer formed on the BBM exhibited improved antithrombotic capability as indicated by higher production of nitric oxide and prostacyclin(PGI2).Furthermore,fluorescence images indicated that HUVECs could infiltrate into the BBM,implying theBBM’s ability to enhance transmural endothelialization.Hence,theBBMpossessed the properties to regulate ECbehaviors and allow transmural ingrowth,demonstrating the potential to be applied as the luminal surface of small-diameter vascular implants for rapid endothelialization.
基金The work was financially supported by the National Key Research and Development Program of China(No.2024YFE0206500)the National Science Foundation of China(Nos.22033009,22072156,22073104 and 22121002).
文摘The development of efficient Cu-based heterogeneous catalysts for CO_(2) hydrogenation to methanol has been an appealing subject.Inspired by the concept of inverse catalysts,a series of La_(2)O_(2)CO_(3)/Cu nanorod composites with varying Cu contents(denoted as LOC/Cu-x,where x stands for the mass ratio of La and Cu in the catalysts)were prepared by combining coprecipitation and calcination processes.Remarkable composition-dependence of catalytic activity and selectivity were observed when different LOC/Cu-x(x=0.1,0.2,0.5,1,3 and 5)were used to catalyze the CO_(2) hydrogenation.The predominant product shifted from methane to methanol with the increasing Cu content.The highest reaction rate(13.3 mmol·gCu^(-1)·h^(-1))and methanol selectivity(85.5%)were achieved when LOC/Cu-1 was tested at 200℃.The LOC was not active for the reaction,while the Cu itself displayed poor catalytic performance.The Cu–LOC interactions significantly affected the nature of the catalysts,including mutual electron transfer,crystal structure,morphology,porosity,surface Cu valence and capability of adsorbing the reactant gases,etc.,which account for the outstanding behavior of the LOC/Cu-1 catalyst.This work provides a new strategy for the design and optimization of Cu-based catalysts.
基金supported by the National Natural Science Foundation of China(grant Nos.42265011,41765009,and 52064037)the Training Program for Academic and Technical Leaders of Major Disciplines in Jiangxi Province,China(grant No.20212BCJL23054)。
文摘Biomass is considered a renewable and cleaner energy source alternative to fossil fuels.In recent years,industrial biomass boilers have been rapidly developed and widely used in the industrial field.This work makes a review on the fuel types used in industrial biomass boilers,the fuel characteristics and the characteristics of air pollutants emitted from the combustion of industrial biomass boilers and other contents in different studies.However,the existing research still has many deficiencies.In the future,further research on biomass fuel,industrial biomass boiler combustion process and the pollutants emitted by industrial biomass boiler combustion,especially the carbonaceous aerosol emitted by in-dustrial biomass boiler and carbonaceous aerosol optical properties still need to be made.At the same time,the potential harm of carbonaceous aerosols emitted from industrial biomass boiler sources to human health and climate change needs to be studied in depth.This review provides a scientific basis for the accurate evaluation of industrial biomass boilers and the effective prevention and control of various pollutants of industrial biomass boilers.
基金The project is supported by the Fundamental Research Funds for the Central Universities(grant No.2232017A-05,2232019A3-06)Science and Technology Support Program of Shanghai(grant No.16441903803,18441902600)the Chinese Universities Scientific Fund(grant No.CUSF-DH-D-2017012)and 111 project(grant No.B07024).
文摘Recent progress in bioresorbable stents(BRSs)has provided a promising alternative for treating coronary artery disease.However,there is still lack of BRSs with satisfied compression and degradation performance for pediatric patients with congenital heart disease,leading to suboptimal therapy effects.Here,we developed a mechanically self-reinforced composite bioresorbable stent(cBRS)for congenital heart disease application.The cBRS consisted of poly(p-dioxanone)monofilaments and polycaprolactone/poly(p-dioxanone)core-shell composite yarns.Interlacing points in cBRS structure were partially bonded,offering the cBRS with significantly higher compression force compared to typical braids and remained good compliance.The suitable degradation profile of the cBRS can possibly preserve vascular remodeling and healing process.In addition,the controllable structural organization provides a method to customize the performance of the cBRS by altering the proportion of different components in the braids.The in vivo results suggested the cBRS supported the vessel wall similar to that of metallic stent.In both abdominal aorta and iliac artery of porcine,cBRS was entirely endothelialized within 1 month and maintained target vessels with good patency in the 12-month follow-up.The in vivo degradation profile of the cBRS is consistent with static degradation results in vitro.It is also demonstrated that there is minimal impact of pulsatile pressure of blood flow and variation of radial force on the degradation rate of the cBRS.Moreover,the lumen of cBRS implanted vessels were enlarged after 6 months,and significantly larger than the vessels implanted with metallic stent in 12 months.
文摘Fe3O4 nano-whiskers were synthesized via ultrasonic-aided reduction of FeCl2.4H2O with N2H4-H2O in concentrated NaOH solution. Phase identification and morphology observation were conducted by X-ray diffraction （XRD） analysis, transmission electron microscopy （TEM） and field emission scanning electron microscopy （FE-SEM）. Face scanning energy dispersive spectrum （face scanning EDS） and twodimensional fast Fourier transform （2DFFF） for element distribution were carried out for confirming composition homogeneity. From XRD and TEIVI, the synthesized Fe304 nano-whiskers are of cubic phase with average dimension of 20 nm~ 200 nm （average aspect ratio of 10）. FE-SEM shows that the nanowhiskers without dispersion are interconnected into a network at a scale of 20μm. 2DFFT of the distribution of Fe and O from face scanning EDS confirms the composition homogeneity of the synthesized Fe3O4. Hydrazine hydrate determines the formation of the nano-whiskers, while the possible mechanism is the preferred growth along certain orientation with the aid of ultrasonic treatment.
文摘Recent advances in fluorescence microscopy have provided researchers with powerful new tools to visualize cellular processes occurring in real time, giving researchers an unprecedented opportunity to address many biological questions that were previously inaccessible. With respect to neurobiology, these real-time imaging techniques have deepened our understanding of molecular and cellular processes, including the movement and dynamics of single proteins and organelles in living cells. In this review, we summarize recent advances in the field of real-time imaging of single synaptic vesicles in live neurons.
