Sodium-ion batteries have emerged as competitive substitutes for low-temperature applications due to severe capacity loss and safety concerns of lithium-ion batteries at−20°C or lower.However,the key capability o...Sodium-ion batteries have emerged as competitive substitutes for low-temperature applications due to severe capacity loss and safety concerns of lithium-ion batteries at−20°C or lower.However,the key capability of ultrafast charging at ultralow temperature for SIBs is rarely reported.Herein,a hybrid of Bi nanoparticles embedded in carbon nanorods is demonstrated as an ideal material to address this issue,which is synthesized via a high temperature shock method.Such a hybrid shows an unprecedented rate performance(237.9 mAh g^(−1) at 2 A g^(−1))at−60℃,outperforming all reported SIB anode materials.Coupled with a Na_(3)V_(2)(PO_(4))_(3)cathode,the energy density of the full cell can reach to 181.9 Wh kg^(−1) at−40°C.Based on this work,a novel strategy of high-rate activation is proposed to enhance performances of Bi-based materials in cryogenic conditions by creating new active sites for interfacial reaction under large current.展开更多
Electrocatalytic reduction of carbon dioxide(CO_(2))to carbon monoxide(CO)is an effective strategy to achieve carbon neutrality.High selective and low-cost catalysts for the electrocatalytic reduction of CO_(2)have re...Electrocatalytic reduction of carbon dioxide(CO_(2))to carbon monoxide(CO)is an effective strategy to achieve carbon neutrality.High selective and low-cost catalysts for the electrocatalytic reduction of CO_(2)have received increasing attention.In contrast to the conventional tube furnace method,the high-temperature shock(HTS)method enables ultra-fast thermal processing,superior atomic efficiency,and a streamlined synthesis protocol,offering a simplified method for the preparation of high-performance single-atom catalysts(SACs).The reports have shown that nickel-based SACs can be synthesized quickly and conveniently using the HTS method,making their application in CO_(2)reduction reactions(CO_(2)RR)a viable and promising avenue for further exploration.In this study,the effect of heating temperature,metal loading and different nitrogen(N)sources on the catalyst morphology,coordination environment and electrocatalytic performance were investigated.Under optimal conditions,0.05Ni-DCD-C-1050 showed excellent performance in reducing CO_(2)to CO,with CO selectivity close to 100%(−0.7 to−1.0 V vs RHE)and current density as high as 130 mA/cm^(2)(−1.1 V vs RHE)in a flow cell under alkaline environment.展开更多
The influence of high temperature effects on the protrusion of Mach stem in strong shock reflection over a wedge was numerically investigated. A two-dimensional inviscid solver applies finite volume method and unstruc...The influence of high temperature effects on the protrusion of Mach stem in strong shock reflection over a wedge was numerically investigated. A two-dimensional inviscid solver applies finite volume method and unstructured quadrilateral grids were employed to simulate the flow. Theoretical analysis was also conducted to understand the phenomenon. Both numerical and theoretical results indicate a wall-jet penetrating forward is responsible for the occurrence of Mach stem protrusion. The protrusion degree seems to depend on the thermal energy buffer capacity of the testing gas. Approaches to increase the energy buffer capacity, such as vibrational relaxation, molecular dissociation, and increase of frozen heat caoacitv, all tend to escalate the orotrusion effect.展开更多
Mo_(2)N has been identified as a highly promising carrier for electrocatalysis. However, its complex synthesis method, use of toxic gases, and serious effects on supported noble metals catalyst during hightemperature ...Mo_(2)N has been identified as a highly promising carrier for electrocatalysis. However, its complex synthesis method, use of toxic gases, and serious effects on supported noble metals catalyst during hightemperature sintering processes have seriously affected its hydrogen evolution reaction(HER) activity and stability. Here, we report an efficient strategy for synthesizing Mo_(2)N using the high temperature shock(HTS) method in just 1.67 s, while also uniformly loading Ru onto Mo_(2)N nanosheets. The HTS enables the homogeneous dispersion of the noble metal Ru, leading to an increased electrocatalytic activity,along with a strong charge transfer between Mo_(2)N and Ru. Ru/Mo2N exhibited an overpotential of 66 m V at 10 m A/cm^(2)in 1 mol/L KOH. In the evaluation of catalytic activity, Ru/Mo_(2)N demonstrates superiority over commercial Pt/C catalysts in terms of mass activity(1.71 A/mg Ru vs. 0.91 A/mg Pt at 200 m V) and turnover frequency(1.41 s^(-1)vs. 0.18 s^(-1)at 100 m V). This result provides a rational and effective pathway for the preparation of efficient electrocatalysts.展开更多
This study examined the inflationary effects of rising temperatures by linking monthly climate variables with consumer price data for 30 large-and medium-sized Chinese cities from January 2004 to December 2019.Lagged ...This study examined the inflationary effects of rising temperatures by linking monthly climate variables with consumer price data for 30 large-and medium-sized Chinese cities from January 2004 to December 2019.Lagged one-period temperature had a significant positive effect on current-month price changes.The cumulative estimates indicated that each 1°C increase during the sample period was associated with a O.057 percent rise in prices,implying that temperature shocks contributed to consumer price inflation.Mechanism tests showed that higher temperatures reduced output growth and raised production costs,and that greater economic policy uncertainty amplified these effects.When different temperature bins were used as explanatory variables,prices increased linearly with temperatures up to 2530°C,then declined at higher temperatures.Temperature effects were stronger in poorer or coolerregions.The findings suggest the need to strengthen monetary policy responses,expand mitigation efforts,and develop climate-adaptive urban systems.展开更多
In recent years,in order to improve the destructive effectiveness of munitions,the use of new types of destructive elements is an important way to improve destructive effectiveness.As a new type of reactive material,r...In recent years,in order to improve the destructive effectiveness of munitions,the use of new types of destructive elements is an important way to improve destructive effectiveness.As a new type of reactive material,reactive alloy contains a large portion of reactive metal elements(Al,Mg,Ti,Zr,etc.),which breaks up under high-velocity impact conditions,generating a large number of high-temperature combustible fragments,which undergo a violent combustion reaction with air.Compared with traditional metal polymers(Al-PTFE)and other reactive composites,it has higher density and strength,excellent mechanical properties and broader application prospects.Currently,researchers have mainly investigated the impact energy release mechanism of reactive alloys through impact tests,and found that there are several important stages in the process of the material from fragmentation to reaction,i.e.,impact fragmentation of the material,rapid heating and combustion reaction.This paper focuses on three problems that need to be solved in the impact-induced energy release process of reactive alloys,namely:the fragmentation mechanism and size distribution law of the fragments produced by the impact of the material on the target,the relationship between the transient temperatures and the size of the fragments,and the reaction temperatures and size thresholds of the fragments to undergo the chemical reaction.The current status of the research of the above problems is reviewed,some potential directions to reveal the impact induced reaction mechanism of reactive alloy is discussed.展开更多
A comprehensive model that included mechanical dynamics of the shock absorber coupled with its thermal properties was proposed innovatively.Moreover a thermal-mechanical coupled model which reflected the closed-loop p...A comprehensive model that included mechanical dynamics of the shock absorber coupled with its thermal properties was proposed innovatively.Moreover a thermal-mechanical coupled model which reflected the closed-loop positive feedback system was established by using MATLAB/SIMULINK,and some curves of shock absorber temperature rising characteristic were obtained by simulation ＆computation under several operating modes and different parameters conditions.Research results show that：shock absorber design parameters,external excitations,and thermo-physical properties parameter,such as oil density have effect on the shock absorber temperature rising characteristic.However other thermo-physical properties parameters,such as oil specific heat,cylinder density,cylinder specific heat,and cylinder thermal conductivity,have no effect on it.The results may be used for studying reliability design of the shock absorber.展开更多
Refrigeration is considered a prime technology for preserving meat products.Temperature alterations are commonly ignored by industry during refrigeration,which have impacts on product quality.Thus,we conducted researc...Refrigeration is considered a prime technology for preserving meat products.Temperature alterations are commonly ignored by industry during refrigeration,which have impacts on product quality.Thus,we conducted research on pork loin and salmon fllets that were preserved for o,5,9,12,and 15 d,where different temperature fluctuations and shocks were established on 4℃.Data revealed that several meat parameters such as total volatile basic nitrogen,total viable count,and lipid oxidation were significantly changed in the±2 C fluctuations group compared with the constant temperature group.Additionally,both the temperature fluctuations and shocks groups had accelerated myofibril protein degrad-ation,while desmin expression and species richness/diversity of bacteria were significantly reduced in the±2℃fluctuations group compared with the constant temperature group.Briefly,temperature fluctuations and shocks accelerated the destruction of muscle structural integrity.Furthermore,both conditions accelerated meat spoilage by progressively expanding the water-loss channels,which can reduce meat edibility.This study provides a new theoretical basis for the proper use of refrigerated temperatures for storing meat products.展开更多
This paper considers the task of evaluating micro-accelerations arising due to the temperature shock of large elastic elements when a small spacecraft leaves the Earth’s shadow.In this case, a one-dimensional model o...This paper considers the task of evaluating micro-accelerations arising due to the temperature shock of large elastic elements when a small spacecraft leaves the Earth’s shadow.In this case, a one-dimensional model of thermal conductivity is used. Its solution wasobtained by the method of direct approximation with the construction of differenceschemes. It is shown that the accuracy of estimating micro-accelerations is commensurate with the accuracy of solving by a three-dimensional model of thermal conductivity.The proposed model allows reducing the time to obtain estimates and significantly simplifies the task at hand. The results of the work can be used in the formation of thedynamic characteristics of a small spacecraft for technological purposes.展开更多
The shock temperatures of water under 35-50 GPa are firstly measured by the optical pyrometry technique. Cν is a constant below 51 GPa (Cν=7.07R), and increases with the temperature above 51 GPa (Cν=(5.76+3.84×...The shock temperatures of water under 35-50 GPa are firstly measured by the optical pyrometry technique. Cν is a constant below 51 GPa (Cν=7.07R), and increases with the temperature above 51 GPa (Cν=(5.76+3.84×10-4T)R). From our calculation, the dissociation has little effect on Cν. But the electron is essential to the Cν calculation.展开更多
The development of sustainable energy storage solutions has driven research toward alternatives to lithiumion batteries.Sodium-ion battery(SIB)was considered a promising candidate due to their cost-effectiveness and s...The development of sustainable energy storage solutions has driven research toward alternatives to lithiumion batteries.Sodium-ion battery(SIB)was considered a promising candidate due to their cost-effectiveness and sodium abundance.To introduce defects and enhance the electrochemical performance of O_(3)-phase sodium-ion layered oxide materials,high-temperature shock(HTS)was employed.However,given the characteristics of HTS,especially the rapid heating rate and short sintering time,suitable precursor systems need to be explored.We systematically compared three precursor systems:traditional metal oxides(HTS-O),decomposable salts(HTS-D),and a novel pre-reacted precursor system(HTS-S).The pre-reacted precursor,developed by leveraging the ethanol solubility of C_(4)H_(14)MnO_(8) and modified ball milling conditions,enabled rapid O_(3) phase formation and resulted in impurity-free O_(3)-NaCu_(0.2)Fe_(0.3)Mn _(0.5)O_(2).This material demonstrated superior electrochemical performance,achieving a discharge capacity of 144.05 mAh g^(−1) within 2.0-4.1 V,along with enhanced rate capabilities.Our findings underscore the critical role of precursor selection and modification in HTS synthesis,contributing to the advancement of high-performance sodium-ion battery materials.展开更多
Single atom catalysts(SACs)featuring Fe-N4 active sites anchored on carbon supports exhibit exceptional electrocatalytic performance in oxygen reduction reactions(ORR).Herein,a rigid ligand confined strategy was used ...Single atom catalysts(SACs)featuring Fe-N4 active sites anchored on carbon supports exhibit exceptional electrocatalytic performance in oxygen reduction reactions(ORR).Herein,a rigid ligand confined strategy was used to synthesize edge-anchored Fe-N_(4) active sites with geometric distortion on mesoporous-dominated carbon spheres(Fe-N-MESs).Furthermore,in situ Fourier transform infrared spectroscopy(FTIR)demonstrates that Fe-N-MESs weaken the O-O band,inhibiting the formation of H_(2)O_(2).The density functional theory(DFT)calculations reveal that the exceptional ORR activity stems from optimized oxygen intermediate adsorption free energy and reduced OH*desorption energy barrier.Electrochemical measurements verify the remarkable ORR activity of Fe-N-MESs,demonstrating a half-wave potential of 0.90 V and excellent stability,with approximately 94%of the initial current density after 50 h of operation.When used as the air cathode in aqueous Zn-air batteries,Fe-N-MESs display a large open circuit voltage of 1.53 V and an extra-long stability of 1500 h.Moreover,Fe-N-MESs exhibit a remarkable open circuit voltage of 1.50 V and an impressive peak power density up to 260.4 mW·cm^(−2) in quasi-solid-state Zn-air batteries.This work provides valuable insights into the boosted ORR origin,while offering a novel and economical synthesis technique for SACs applicable to other electrocatalytic reactions.展开更多
Large olivine samples were hot-pressed synthesized for shock wave experiments. The shock wave experiments were carried out at pressure range between 11 and 42 GPa. Shock data on olivine sample yielded a linear relatio...Large olivine samples were hot-pressed synthesized for shock wave experiments. The shock wave experiments were carried out at pressure range between 11 and 42 GPa. Shock data on olivine sample yielded a linear relationship between shock wave velocity D and particle velocity u described by D=3.56(?0.13)+2.57(?0.12)u. The shock temperature is determined by an energy relationship which is approximately 790°C at pressure 28 GPa. Due to low temperature and short experimental duration, we suggest that no phase change occurred in our sample below 30 GPa and olivine persisted well beyond its equilibrium boundary in metastable phase. The densities of metastable olivine are in agreement with the results of static compression. At the depth shallower than 410 km, the densities of metastable olivine are higher than those of the PREM model, facilitating cold slab to sink into the mantle transition zone. However, in entire mantle transition zone, the shock densities are lower than those of the PREM model, hampering cold slab to flow across the "660 km" phase boundary.展开更多
基金supported from Science and Technology Development Program of Jilin Province(Nos.20240101128JC,20230402058GH)National Natural Science Foundation of China(No.52130101).
文摘Sodium-ion batteries have emerged as competitive substitutes for low-temperature applications due to severe capacity loss and safety concerns of lithium-ion batteries at−20°C or lower.However,the key capability of ultrafast charging at ultralow temperature for SIBs is rarely reported.Herein,a hybrid of Bi nanoparticles embedded in carbon nanorods is demonstrated as an ideal material to address this issue,which is synthesized via a high temperature shock method.Such a hybrid shows an unprecedented rate performance(237.9 mAh g^(−1) at 2 A g^(−1))at−60℃,outperforming all reported SIB anode materials.Coupled with a Na_(3)V_(2)(PO_(4))_(3)cathode,the energy density of the full cell can reach to 181.9 Wh kg^(−1) at−40°C.Based on this work,a novel strategy of high-rate activation is proposed to enhance performances of Bi-based materials in cryogenic conditions by creating new active sites for interfacial reaction under large current.
基金supported by the National Key R&D Program of China(2024YFB4106400)National Natural Science Foundation of China(22209200,52302331)。
文摘Electrocatalytic reduction of carbon dioxide(CO_(2))to carbon monoxide(CO)is an effective strategy to achieve carbon neutrality.High selective and low-cost catalysts for the electrocatalytic reduction of CO_(2)have received increasing attention.In contrast to the conventional tube furnace method,the high-temperature shock(HTS)method enables ultra-fast thermal processing,superior atomic efficiency,and a streamlined synthesis protocol,offering a simplified method for the preparation of high-performance single-atom catalysts(SACs).The reports have shown that nickel-based SACs can be synthesized quickly and conveniently using the HTS method,making their application in CO_(2)reduction reactions(CO_(2)RR)a viable and promising avenue for further exploration.In this study,the effect of heating temperature,metal loading and different nitrogen(N)sources on the catalyst morphology,coordination environment and electrocatalytic performance were investigated.Under optimal conditions,0.05Ni-DCD-C-1050 showed excellent performance in reducing CO_(2)to CO,with CO selectivity close to 100%(−0.7 to−1.0 V vs RHE)and current density as high as 130 mA/cm^(2)(−1.1 V vs RHE)in a flow cell under alkaline environment.
文摘The influence of high temperature effects on the protrusion of Mach stem in strong shock reflection over a wedge was numerically investigated. A two-dimensional inviscid solver applies finite volume method and unstructured quadrilateral grids were employed to simulate the flow. Theoretical analysis was also conducted to understand the phenomenon. Both numerical and theoretical results indicate a wall-jet penetrating forward is responsible for the occurrence of Mach stem protrusion. The protrusion degree seems to depend on the thermal energy buffer capacity of the testing gas. Approaches to increase the energy buffer capacity, such as vibrational relaxation, molecular dissociation, and increase of frozen heat caoacitv, all tend to escalate the orotrusion effect.
基金supported by the Beijing Natural Science Foundation (No. 2232061)the National Natural Science Foundation of China (No. 42377227)。
文摘Mo_(2)N has been identified as a highly promising carrier for electrocatalysis. However, its complex synthesis method, use of toxic gases, and serious effects on supported noble metals catalyst during hightemperature sintering processes have seriously affected its hydrogen evolution reaction(HER) activity and stability. Here, we report an efficient strategy for synthesizing Mo_(2)N using the high temperature shock(HTS) method in just 1.67 s, while also uniformly loading Ru onto Mo_(2)N nanosheets. The HTS enables the homogeneous dispersion of the noble metal Ru, leading to an increased electrocatalytic activity,along with a strong charge transfer between Mo_(2)N and Ru. Ru/Mo2N exhibited an overpotential of 66 m V at 10 m A/cm^(2)in 1 mol/L KOH. In the evaluation of catalytic activity, Ru/Mo_(2)N demonstrates superiority over commercial Pt/C catalysts in terms of mass activity(1.71 A/mg Ru vs. 0.91 A/mg Pt at 200 m V) and turnover frequency(1.41 s^(-1)vs. 0.18 s^(-1)at 100 m V). This result provides a rational and effective pathway for the preparation of efficient electrocatalysts.
基金Planning Fund Projects of Humanities and Social Sciences Research,Ministry of Education(No.25YJA790036)the Fundamental Research Funds for the Central Universities(No.2042024kf0005).
文摘This study examined the inflationary effects of rising temperatures by linking monthly climate variables with consumer price data for 30 large-and medium-sized Chinese cities from January 2004 to December 2019.Lagged one-period temperature had a significant positive effect on current-month price changes.The cumulative estimates indicated that each 1°C increase during the sample period was associated with a O.057 percent rise in prices,implying that temperature shocks contributed to consumer price inflation.Mechanism tests showed that higher temperatures reduced output growth and raised production costs,and that greater economic policy uncertainty amplified these effects.When different temperature bins were used as explanatory variables,prices increased linearly with temperatures up to 2530°C,then declined at higher temperatures.Temperature effects were stronger in poorer or coolerregions.The findings suggest the need to strengthen monetary policy responses,expand mitigation efforts,and develop climate-adaptive urban systems.
文摘In recent years,in order to improve the destructive effectiveness of munitions,the use of new types of destructive elements is an important way to improve destructive effectiveness.As a new type of reactive material,reactive alloy contains a large portion of reactive metal elements(Al,Mg,Ti,Zr,etc.),which breaks up under high-velocity impact conditions,generating a large number of high-temperature combustible fragments,which undergo a violent combustion reaction with air.Compared with traditional metal polymers(Al-PTFE)and other reactive composites,it has higher density and strength,excellent mechanical properties and broader application prospects.Currently,researchers have mainly investigated the impact energy release mechanism of reactive alloys through impact tests,and found that there are several important stages in the process of the material from fragmentation to reaction,i.e.,impact fragmentation of the material,rapid heating and combustion reaction.This paper focuses on three problems that need to be solved in the impact-induced energy release process of reactive alloys,namely:the fragmentation mechanism and size distribution law of the fragments produced by the impact of the material on the target,the relationship between the transient temperatures and the size of the fragments,and the reaction temperatures and size thresholds of the fragments to undergo the chemical reaction.The current status of the research of the above problems is reviewed,some potential directions to reveal the impact induced reaction mechanism of reactive alloy is discussed.
基金Supported by Central Universities Fundamental Research Projects Foundation(11QG22)State Key Laboratory of Automobile Noise Vibration and Safety Projects Foundation(NVHSKL-201105)
文摘A comprehensive model that included mechanical dynamics of the shock absorber coupled with its thermal properties was proposed innovatively.Moreover a thermal-mechanical coupled model which reflected the closed-loop positive feedback system was established by using MATLAB/SIMULINK,and some curves of shock absorber temperature rising characteristic were obtained by simulation ＆computation under several operating modes and different parameters conditions.Research results show that：shock absorber design parameters,external excitations,and thermo-physical properties parameter,such as oil density have effect on the shock absorber temperature rising characteristic.However other thermo-physical properties parameters,such as oil specific heat,cylinder density,cylinder specific heat,and cylinder thermal conductivity,have no effect on it.The results may be used for studying reliability design of the shock absorber.
基金supported by the Starry Night Science Fund of Zhejiang University Shanghai Institute for Advanced Study(No.SN-ZJU-SIAS-0013)the National Key Technology Research and Development Program of China(No.2016YFD0401201).
文摘Refrigeration is considered a prime technology for preserving meat products.Temperature alterations are commonly ignored by industry during refrigeration,which have impacts on product quality.Thus,we conducted research on pork loin and salmon fllets that were preserved for o,5,9,12,and 15 d,where different temperature fluctuations and shocks were established on 4℃.Data revealed that several meat parameters such as total volatile basic nitrogen,total viable count,and lipid oxidation were significantly changed in the±2 C fluctuations group compared with the constant temperature group.Additionally,both the temperature fluctuations and shocks groups had accelerated myofibril protein degrad-ation,while desmin expression and species richness/diversity of bacteria were significantly reduced in the±2℃fluctuations group compared with the constant temperature group.Briefly,temperature fluctuations and shocks accelerated the destruction of muscle structural integrity.Furthermore,both conditions accelerated meat spoilage by progressively expanding the water-loss channels,which can reduce meat edibility.This study provides a new theoretical basis for the proper use of refrigerated temperatures for storing meat products.
文摘This paper considers the task of evaluating micro-accelerations arising due to the temperature shock of large elastic elements when a small spacecraft leaves the Earth’s shadow.In this case, a one-dimensional model of thermal conductivity is used. Its solution wasobtained by the method of direct approximation with the construction of differenceschemes. It is shown that the accuracy of estimating micro-accelerations is commensurate with the accuracy of solving by a three-dimensional model of thermal conductivity.The proposed model allows reducing the time to obtain estimates and significantly simplifies the task at hand. The results of the work can be used in the formation of thedynamic characteristics of a small spacecraft for technological purposes.
基金supported by the Auspices of the Science Foundation (Grant No. 10874141)
文摘The shock temperatures of water under 35-50 GPa are firstly measured by the optical pyrometry technique. Cν is a constant below 51 GPa (Cν=7.07R), and increases with the temperature above 51 GPa (Cν=(5.76+3.84×10-4T)R). From our calculation, the dissociation has little effect on Cν. But the electron is essential to the Cν calculation.
基金supported by the National Natural Science Foundation of China(92372107,52304338,and 52171219)。
文摘The development of sustainable energy storage solutions has driven research toward alternatives to lithiumion batteries.Sodium-ion battery(SIB)was considered a promising candidate due to their cost-effectiveness and sodium abundance.To introduce defects and enhance the electrochemical performance of O_(3)-phase sodium-ion layered oxide materials,high-temperature shock(HTS)was employed.However,given the characteristics of HTS,especially the rapid heating rate and short sintering time,suitable precursor systems need to be explored.We systematically compared three precursor systems:traditional metal oxides(HTS-O),decomposable salts(HTS-D),and a novel pre-reacted precursor system(HTS-S).The pre-reacted precursor,developed by leveraging the ethanol solubility of C_(4)H_(14)MnO_(8) and modified ball milling conditions,enabled rapid O_(3) phase formation and resulted in impurity-free O_(3)-NaCu_(0.2)Fe_(0.3)Mn _(0.5)O_(2).This material demonstrated superior electrochemical performance,achieving a discharge capacity of 144.05 mAh g^(−1) within 2.0-4.1 V,along with enhanced rate capabilities.Our findings underscore the critical role of precursor selection and modification in HTS synthesis,contributing to the advancement of high-performance sodium-ion battery materials.
基金supported financially by the National Natural Science Foundation of China(No.52172208)Taishan Scholar Young Talent Program(No.tsqn202306216).XAS beamlines at the Australian Synchrotron in Melbourne are gratefully acknowledged.
文摘Single atom catalysts(SACs)featuring Fe-N4 active sites anchored on carbon supports exhibit exceptional electrocatalytic performance in oxygen reduction reactions(ORR).Herein,a rigid ligand confined strategy was used to synthesize edge-anchored Fe-N_(4) active sites with geometric distortion on mesoporous-dominated carbon spheres(Fe-N-MESs).Furthermore,in situ Fourier transform infrared spectroscopy(FTIR)demonstrates that Fe-N-MESs weaken the O-O band,inhibiting the formation of H_(2)O_(2).The density functional theory(DFT)calculations reveal that the exceptional ORR activity stems from optimized oxygen intermediate adsorption free energy and reduced OH*desorption energy barrier.Electrochemical measurements verify the remarkable ORR activity of Fe-N-MESs,demonstrating a half-wave potential of 0.90 V and excellent stability,with approximately 94%of the initial current density after 50 h of operation.When used as the air cathode in aqueous Zn-air batteries,Fe-N-MESs display a large open circuit voltage of 1.53 V and an extra-long stability of 1500 h.Moreover,Fe-N-MESs exhibit a remarkable open circuit voltage of 1.50 V and an impressive peak power density up to 260.4 mW·cm^(−2) in quasi-solid-state Zn-air batteries.This work provides valuable insights into the boosted ORR origin,while offering a novel and economical synthesis technique for SACs applicable to other electrocatalytic reactions.
基金the National Natural Science Foundation of China (Grant Nos. 41174074 & 41174073)the Knowledge Innovation Project of the Chinese Academy of Sciences (Grant No. KZCX2-EW-118)
文摘Large olivine samples were hot-pressed synthesized for shock wave experiments. The shock wave experiments were carried out at pressure range between 11 and 42 GPa. Shock data on olivine sample yielded a linear relationship between shock wave velocity D and particle velocity u described by D=3.56(?0.13)+2.57(?0.12)u. The shock temperature is determined by an energy relationship which is approximately 790°C at pressure 28 GPa. Due to low temperature and short experimental duration, we suggest that no phase change occurred in our sample below 30 GPa and olivine persisted well beyond its equilibrium boundary in metastable phase. The densities of metastable olivine are in agreement with the results of static compression. At the depth shallower than 410 km, the densities of metastable olivine are higher than those of the PREM model, facilitating cold slab to sink into the mantle transition zone. However, in entire mantle transition zone, the shock densities are lower than those of the PREM model, hampering cold slab to flow across the "660 km" phase boundary.
