A comprehensive understanding of the dynamic processes at the catalyst/electrolyte interfaces is crucial for the development of advanced electrocatalysts for the oxygen evolution reaction(OER).However,the chemical pro...A comprehensive understanding of the dynamic processes at the catalyst/electrolyte interfaces is crucial for the development of advanced electrocatalysts for the oxygen evolution reaction(OER).However,the chemical processes related to surface corrosion and catalyst degradation have not been well understood so far.In this study,we employ LiCoO_(2) as a model catalyst and observe distinct OER activities and surface stabilities in different alkaline solutions.Operando X-ray diffraction(XRD)and online mass spectroscopy(OMS)measurements prove the selective intercalation of alkali cations into the layered structure of LiCoO_(2) during OER.It is proposed that the dynamic cation intercalations facilitate the chemical oxidation process between highly oxidative Co species and adsorbed water molecules,triggering the so-called electrochemical-chemical reaction mechanism(EC-mechanism).The results of this study emphasize the influence of cations on OER and provide insights into new strategies for achieving both high activity and stability in high-performance OER catalysts.展开更多
The development of non‐precious metal catalysts that facilitate the oxygen evolution reaction(OER)is important for the widespread application of hydrogen production by water splitting.Various perovskite oxides have b...The development of non‐precious metal catalysts that facilitate the oxygen evolution reaction(OER)is important for the widespread application of hydrogen production by water splitting.Various perovskite oxides have been employed as active OER catalysts,however,the underlying mechanism that occurs at the catalyst‐electrolyte interface is still not well understood,prohibiting the design and preparation of advanced OER catalysts.Here,we report a systematic investigation into the effect of proton dynamics on the catalyst‐electrolyte interfaces of four perovskite catalysts:La_(0.5)Sr_(0.5)CoO_(3‐δ)(LSCO),LaCoO_(3),LaFeO_(3),and LaNiO_(3).The pH‐dependent OER activities,H/D kinetic isotope effect,and surface functionalization with phosphate anion groups were investigated to elucidate the role of proton dynamics in the rate‐limiting steps of the OER.For oxides with small charge‐transfer energies,such as LSCO and LaNiO_(3),non‐concerted proton‐coupled electron transfer steps are involved in the OER,and the activity is strongly controlled by the proton dynamics on the catalyst surface.The results demonstrate the important role of interfacial proton transfer in the OER mechanism,and suggest that proton dynamics at the interface should carefully be considered in the design of future high‐performance catalysts.展开更多
Kinetic behaviors of niobium and titanium carbide precipitates in iron are simulated with cluster dynamics.The simulations,carried out in austenite and ferrite for niobium carbides,and in austenite for titanium carbid...Kinetic behaviors of niobium and titanium carbide precipitates in iron are simulated with cluster dynamics.The simulations,carried out in austenite and ferrite for niobium carbides,and in austenite for titanium carbide,are analyzed for dependences on temperature,solute concentration,and initial cluster distribution.The results are presented for different temperatures and solute concentrations,compared to experimental data available.They show little impact of initial cluster distribution beyond a certain relaxation time and that highly dilute alloys with monomers only present a significantly different behavior from denser alloys or ones with different initial cluster distributions.展开更多
Testes,which are mainly responsible for producing sperm and secreting male hormones,are the functional center of the male reproductive system in mammals.During embryonic development in mammals with descended testes,th...Testes,which are mainly responsible for producing sperm and secreting male hormones,are the functional center of the male reproductive system in mammals.During embryonic development in mammals with descended testes,the testicles descend from the urogenital ridge to the scrotum,located outside the body cavity (Hutson et al.,2015).展开更多
Ultralong organic phosphorescence(UOP)materials have roused considerable attention in the field of photonics and optoelectronics owing to the feature of long-lived emission lifetimes.However,to develop UOP materials w...Ultralong organic phosphorescence(UOP)materials have roused considerable attention in the field of photonics and optoelectronics owing to the feature of long-lived emission lifetimes.However,to develop UOP materials with color-tunability is still a formidable challenge.Here,we report a class of UOP materials containing carbonyl,amino or amide groups,exhibiting colortunable persistent luminescence ranging from blue(458 nm)to yellow-green(508 nm)under different UV wavelength excitation.Taken theoretical and experimental results together,we conclude that the excitation dependent color-tunable UOP emission is ascribed to multiple emission centers from single molecular and aggregated states in crystal.Given color-tunable UOP feature,these materials are used to successfully realize visual UV-light detection.This finding not only provides a strategy to design new organic phosphorescent molecules with colorful emission,but also extends the scope of the applications of purely organic phosphorescent materials.展开更多
Developing ultralong organic phosphorescence(UOP)materials with smart response to external stimuli is of great interest in photonics applications,whereas the manipulation of molecular stacking on tuning such dynamic U...Developing ultralong organic phosphorescence(UOP)materials with smart response to external stimuli is of great interest in photonics applications,whereas the manipulation of molecular stacking on tuning such dynamic UOP is still a formidable challenge.Herein,we have reported two polymorphs with distinct photoactivated dynamic UOP behavior based on a pyridine derivative for the first time.Our experiment revealed that the dynamic UOP behavior including photoactivation and deactivation feature is highly dependent on irradiation intensity and environmental atmosphere.Additionally,given the unique dynamic UOP feature,these phosphors have been successfully applied to phosphorescence-dependent molecular logic gate and timing data storage.This result not only paves a way to design smart functional materials but also expands the scope of the applications on organic phosphorescence materials.展开更多
Supramolecular organic frameworks(SOFs),due to the atomically precise integration of the repeated building units,exhibit intriguing properties and consequently potential applications in chemical and materials science ...Supramolecular organic frameworks(SOFs),due to the atomically precise integration of the repeated building units,exhibit intriguing properties and consequently potential applications in chemical and materials science communities.However,it remains a great challenge to achieve SOFs with ultralong organic phosphorescence(UOP)in a singlecomponent system.Herein,we report metal-free organic compound 9,9′-(6-(2-bromophenethoxy)-1,3,5-triazine-2,4-diyl)bis(9H-carbazole)(DCzPO)with UOP behavior.Owing to the combination of multiple supramolecular interactions,DCzPO formed a SOF structure with regular hexagonal holes,which shows an ultralong emission lifetime of 398 ms and a phosphorescence efficiency of 3%.So far as we know,among the reported luminescent SOFs,this one is the most highly efficient.This single-component SOF with ultralong phosphorescence will provide a new platform to rationally combine UOP and porous materials.展开更多
Integrating distributed ultra-low-frequency vibration sensing and high-speed fiber optical communication can provide additional functionality under the current submarine telecommunication network,such as ocean seismic...Integrating distributed ultra-low-frequency vibration sensing and high-speed fiber optical communication can provide additional functionality under the current submarine telecommunication network,such as ocean seismic monitoring and geological exploration。展开更多
Passive daytime radiative cooling technology has demonstrated energy-saving potential during the cooling season in buildings.To address the challenge of extra heat loss during the heating season,a temperature-adaptive...Passive daytime radiative cooling technology has demonstrated energy-saving potential during the cooling season in buildings.To address the challenge of extra heat loss during the heating season,a temperature-adaptive radiative cooler(TARC)was developed with a phase change material(PCM)cover and a multilayer daytime radiative cooler(DRC).During a warm month when the ambient temperature exceeded 20℃,the TARC system demonstrated cooling effects as static DRC,and the TARC and DRC achieved average daytime cooling temperatures of 2.5℃ and 4.5℃,respectively.However,during a colder period in December,TARC achieved an average temperature in the cooling space higher than the ambient temperature during the daytime due to the PCM cover being able to switch off infrared radiation from DRC and absorb solar radiation.To maximize energy savings in cooling and heating seasons,we established numerical models for the optimization of PCM cover and TARC.The simulation results showed that the optimized TARC could achieve a daily average temperature drop of 4.1℃ on a hot day and a temperature increase of 1.0℃ on a cold day under the same climatic conditions as the experiments.Further simulations highlight the potential of TARC systems for cross-seasonal applications.展开更多
As an important way of converting mechanical energy into electric energy,a piezoelectric nanogenerator(PENG)has been widely applied in energy harvesting as well as self-powered sensors in recent years.However,its robu...As an important way of converting mechanical energy into electric energy,a piezoelectric nanogenerator(PENG)has been widely applied in energy harvesting as well as self-powered sensors in recent years.However,its robustness and durability are still severely challenged by frequent and inevitable mechanical impacts in real application environments.Herein,a fully selfhealing PENG(FS-PENG)as a self-powered pressure sensing electronic skin is reported.The self-healing piezoelectric composite and self-healing Ag NW electrode fabricated through mixing piezoelectric PZT particles and conductive Ag NWs into self-healing polydimethylsiloxane(H-PDMS)are assembled into the sandwich structure FS-PENG.The FS-PENG could not only effectively convert external stimulation into electrical signals with a linear response to the pressure but also retain the excellent self-healing and stable sensing property after multiple cycles of cutting and self-healing process.Moreover,a self-healing pressure sensor array composed of 9 FS-PENGs was attached on the back of the human hand to mimic the human skin,and accurate monitoring of the spatial position distribution and magnitude of the pressure was successfully realized.展开更多
Understanding the dynamic structural and chemical evolutions at the catalyst-electrolyte interfaces is crucial for the development of active and stable electrocatalysts.In this work,β-Li_(2)IrO_(3)is employed as a mo...Understanding the dynamic structural and chemical evolutions at the catalyst-electrolyte interfaces is crucial for the development of active and stable electrocatalysts.In this work,β-Li_(2)IrO_(3)is employed as a model catalyst for the oxygen evolution reaction(OER).Its elastic three-dimensional Ir-O framework enables us to investigate the Li^(+)cation dissolution-induced structure evolutions and the formation mechanism of amorphous IrO_(x)species.Electrochemical measurements by rotating ring disk electrode(RRDE)reveal that up to 60%of the measured OER current can be ascribed to catalyst degradation.A series of in-situ X-ray diffraction spectroscopy(XRD),X-ray absorption spectroscopy(XAS),and Raman spectroscopy are conducted.Structure vibration is observed with oxidation states of Ir being reduced abnormally during OER at high potentials.It’s hypothesized that the reversible proton intercalations are responsible for the Ir turn-over mechanism.Results of this work demonstrate a stable and elastic iridate structure and reveal the initial catalyst degradation behaviors during OER in acid media.展开更多
China’s accelerator driven subcritical system(ADS)development has made significant progress during the past decade.With the successful construction and operation of the international prototype of ADS superconducting ...China’s accelerator driven subcritical system(ADS)development has made significant progress during the past decade.With the successful construction and operation of the international prototype of ADS superconducting proton linac,the lead-based critical/subcritical zero-power facility VENUS-II and the comprehensive thermal-hydraulic and material test facilities for LBE(lead bismuth eutectic)coolant,China is playing a pivotal role in advanced steady-state operations toward the next step,the ADS project.The China initiative Accelerator Driven System(CiADS)is the next facility for China’s ADS program,aimed to bridge the gaps between the ADS experiment and the LBE cooled subcritical reactor.The total power of the CiADS will reach 10 MW.The CiADS engineering design was approved by Chinese government in 2018.Since then,the CiADS project has been fully transferred to the construction application stage.The subcritical reactor is an important part of the whole CiADS project.Currently,a pool-type LBE cooled fast reactor is chosen as the subcritical reactor of the CiADS.Physical and thermal experiments and software development for LBE coolant were conducted simultaneously to support the design and construction of the CiADS LBEcooled subcritical reactor.Therefore,it is necessary to introduce the efforts made in China in the LBE-cooled fast reactor to provide certain supporting data and reference solutions for further design and development for ADS.Thus,the roadmap of China’s ADS,the development process of the CiADS,the important design of the current CiADS subcritical reactor,and the efforts to build the LBE-cooled fast reactor are presented.展开更多
In the past decades,the progress of wearable and portable electronics is quite rapid,but the power supply has been a great challenge for their practical applications.Wearable power sources,especially wearable energy-h...In the past decades,the progress of wearable and portable electronics is quite rapid,but the power supply has been a great challenge for their practical applications.Wearable power sources,especially wearable energy-harvesting devices,provide some possible solutions for this challenge.Among various wearable energy harvesters,the high-performance fabric-based triboelectric nanogenerators(TENGs)are particularly significant.In this review paper,we first introduce the fundamentals of TENGs and their four basic working modes.Then,we will discuss the material synthesis,device design,and fabrication of fabric-based TENGs.Finally,we try to give some problems that need to be solved for the further development of TENGs.展开更多
Abstract Biodegradable poly（ether-imide-ester） elasto- mers were synthesized from succinic acid, 1,4-butanediol, polyethylene glycol 1000 and N＇,N-bis（2-carboxyethyl）- pyromellitimide which was derived from pyrom...Abstract Biodegradable poly（ether-imide-ester） elasto- mers were synthesized from succinic acid, 1,4-butanediol, polyethylene glycol 1000 and N＇,N-bis（2-carboxyethyl）- pyromellitimide which was derived from pyromellitic dianhydride and glycine. The chemical structures, crystal- linities, thermal stabilities, mechanical properties, hydro- philicities and biodegradabilities of these elastomers were investigated. The hard segments of the linear aliphatic poly （ether-ester） exhibited monoclinic chain packing. Increas- ing the amount of aromatic bisimide moieties in the poly （ether-ester） reduced the crystallinity of the material and improved the thermal stability and tensile strength of the elastomers. In addition, introducing a suitable amount of aromatic bisimide moieties into the poly（ether-ester） backbones endowed the elastomers with improved biode- gradability but too many aromatic bisimide groups reduced the biodegradability of the elastomers.展开更多
The marine environment presents challenges for wound healing in cetaceans,despite their remarkable recovery abilities with minimal infections or complications.However,the molecular mechanism underlying this efficient ...The marine environment presents challenges for wound healing in cetaceans,despite their remarkable recovery abilities with minimal infections or complications.However,the molecular mechanism underlying this efficient wound healing remains underexplored.To better understand the molecular mechanisms behind wound healing in cetaceans,we investigated the evolutionary patterns of 37 wound healing-related genes in representative mammals.We found wound healing-related genes experience adaptive evolution in cetaceans:(1)Three extrinsic coagulation pathway-related genes-tissue factor(F3),coagulation factor VII(F7),and coagulation factor X(F10)-are subject to positive selection in cetaceans,which might promote efficient hemostasis after injury;positive selection in transforming growth factor-beta 2(TGF-β2),transforming growth factor-beta 3(TGF-β3),and platelet-derived growth factor D(PDGFD),which play immunological roles in wound healing,may help cetaceans enhance inflammatory response and tissue debridement.(2)Coagulation factor XII(F12)is the initiation factor in the intrinsic coagulation pathway.It had a premature stop codon mutation and was subjected to selective stress relaxation in cetaceans,suggesting that the early termination of F12 may help cetaceans avoid the risk of vascular blockage during diving.(3)Fibrinogen alpha chain(FGA)and FIII,which were detected to contain the specific amino acid substitutions in marine mammals,indicating similar evolutionary mechanisms might exist among marine mammals to maintain strong wound-healing ability.Thus,our research provides further impetus to study the evolution of the wound healing system in cetaceans and other marine mammals,extending knowledge of preventing coagulation disorder and atherosclerosis in humans.展开更多
基金financially supported by the Shenzhen Science and Technology Innovation Program(Grant No.JCYJ20220530150011024)。
文摘A comprehensive understanding of the dynamic processes at the catalyst/electrolyte interfaces is crucial for the development of advanced electrocatalysts for the oxygen evolution reaction(OER).However,the chemical processes related to surface corrosion and catalyst degradation have not been well understood so far.In this study,we employ LiCoO_(2) as a model catalyst and observe distinct OER activities and surface stabilities in different alkaline solutions.Operando X-ray diffraction(XRD)and online mass spectroscopy(OMS)measurements prove the selective intercalation of alkali cations into the layered structure of LiCoO_(2) during OER.It is proposed that the dynamic cation intercalations facilitate the chemical oxidation process between highly oxidative Co species and adsorbed water molecules,triggering the so-called electrochemical-chemical reaction mechanism(EC-mechanism).The results of this study emphasize the influence of cations on OER and provide insights into new strategies for achieving both high activity and stability in high-performance OER catalysts.
文摘The development of non‐precious metal catalysts that facilitate the oxygen evolution reaction(OER)is important for the widespread application of hydrogen production by water splitting.Various perovskite oxides have been employed as active OER catalysts,however,the underlying mechanism that occurs at the catalyst‐electrolyte interface is still not well understood,prohibiting the design and preparation of advanced OER catalysts.Here,we report a systematic investigation into the effect of proton dynamics on the catalyst‐electrolyte interfaces of four perovskite catalysts:La_(0.5)Sr_(0.5)CoO_(3‐δ)(LSCO),LaCoO_(3),LaFeO_(3),and LaNiO_(3).The pH‐dependent OER activities,H/D kinetic isotope effect,and surface functionalization with phosphate anion groups were investigated to elucidate the role of proton dynamics in the rate‐limiting steps of the OER.For oxides with small charge‐transfer energies,such as LSCO and LaNiO_(3),non‐concerted proton‐coupled electron transfer steps are involved in the OER,and the activity is strongly controlled by the proton dynamics on the catalyst surface.The results demonstrate the important role of interfacial proton transfer in the OER mechanism,and suggest that proton dynamics at the interface should carefully be considered in the design of future high‐performance catalysts.
基金the CAS-TWAS President’s Fellowship Programme for this doctoral fellowship(Grant No.2016CTF004)。
文摘Kinetic behaviors of niobium and titanium carbide precipitates in iron are simulated with cluster dynamics.The simulations,carried out in austenite and ferrite for niobium carbides,and in austenite for titanium carbide,are analyzed for dependences on temperature,solute concentration,and initial cluster distribution.The results are presented for different temperatures and solute concentrations,compared to experimental data available.They show little impact of initial cluster distribution beyond a certain relaxation time and that highly dilute alloys with monomers only present a significantly different behavior from denser alloys or ones with different initial cluster distributions.
基金financially supported by the National Natural Science Foundation of China(31872219,31370401,32030011,31630071,31772448)National Key Programme of Research and Development,Ministry of Science and Technology(2016YFC0503200)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)。
文摘Testes,which are mainly responsible for producing sperm and secreting male hormones,are the functional center of the male reproductive system in mammals.During embryonic development in mammals with descended testes,the testicles descend from the urogenital ridge to the scrotum,located outside the body cavity (Hutson et al.,2015).
基金supported by the National Natural Science Foundation of China(21875104,21975120,21973043,91833304,51673095)the Natural Science Fund for Distinguished Young Scholars of Jiangsu Province(BK20180037)the Fundamental Research Funds for the Central Universities。
文摘Ultralong organic phosphorescence(UOP)materials have roused considerable attention in the field of photonics and optoelectronics owing to the feature of long-lived emission lifetimes.However,to develop UOP materials with color-tunability is still a formidable challenge.Here,we report a class of UOP materials containing carbonyl,amino or amide groups,exhibiting colortunable persistent luminescence ranging from blue(458 nm)to yellow-green(508 nm)under different UV wavelength excitation.Taken theoretical and experimental results together,we conclude that the excitation dependent color-tunable UOP emission is ascribed to multiple emission centers from single molecular and aggregated states in crystal.Given color-tunable UOP feature,these materials are used to successfully realize visual UV-light detection.This finding not only provides a strategy to design new organic phosphorescent molecules with colorful emission,but also extends the scope of the applications of purely organic phosphorescent materials.
基金This work is supported by the National Natural Science Foundation of China(21875104,21975120,21973043,51673095,and 91833302)Natural Science Fund for Distinguished Young Scholars of Jiangsu Province(BK20180037).
文摘Developing ultralong organic phosphorescence(UOP)materials with smart response to external stimuli is of great interest in photonics applications,whereas the manipulation of molecular stacking on tuning such dynamic UOP is still a formidable challenge.Herein,we have reported two polymorphs with distinct photoactivated dynamic UOP behavior based on a pyridine derivative for the first time.Our experiment revealed that the dynamic UOP behavior including photoactivation and deactivation feature is highly dependent on irradiation intensity and environmental atmosphere.Additionally,given the unique dynamic UOP feature,these phosphors have been successfully applied to phosphorescence-dependent molecular logic gate and timing data storage.This result not only paves a way to design smart functional materials but also expands the scope of the applications on organic phosphorescence materials.
基金supported by the National Natural Science Foundation of China(nos.21975120,21875104,21973043,91833304,and 91833302)the National Key R&D Program of China(no.2020YFA0709900)+2 种基金the Natural Science Fund for Distinguished Young Scholars of Jiangsu Province(no.BK20180037)the China National Postdoctoral Program for Innovative Talents(no.BX20200278)the China Postdoctoral Science Foundation(no.2020M673478).
文摘Supramolecular organic frameworks(SOFs),due to the atomically precise integration of the repeated building units,exhibit intriguing properties and consequently potential applications in chemical and materials science communities.However,it remains a great challenge to achieve SOFs with ultralong organic phosphorescence(UOP)in a singlecomponent system.Herein,we report metal-free organic compound 9,9′-(6-(2-bromophenethoxy)-1,3,5-triazine-2,4-diyl)bis(9H-carbazole)(DCzPO)with UOP behavior.Owing to the combination of multiple supramolecular interactions,DCzPO formed a SOF structure with regular hexagonal holes,which shows an ultralong emission lifetime of 398 ms and a phosphorescence efficiency of 3%.So far as we know,among the reported luminescent SOFs,this one is the most highly efficient.This single-component SOF with ultralong phosphorescence will provide a new platform to rationally combine UOP and porous materials.
基金National Natural Science Foundation of China(62435004,U22A2087,U21A20506,62475051)Guangdong Introducing Innovative and Entrepreneurial Teams of the Pearl River Talent Recruitment Program(2021ZT09X044).
文摘Integrating distributed ultra-low-frequency vibration sensing and high-speed fiber optical communication can provide additional functionality under the current submarine telecommunication network,such as ocean seismic monitoring and geological exploration。
基金supported by the National Natural Science Foundation of China(NSFC)(No.51908299)Qing Chuang science and technology plan of colleges and universities in Shandong Province(Sub-Title:Innovative Research Team of Advanced Energy Equipment),Jinan Science and Technology Bureau(No.2021GXRC083,202333015)+1 种基金Science,Education and Industry Integration Innovation Pilot Project from Qilu University of Technology(Shandong Academy of Sciences)(No.2022JBZ02-01)Ningbo Natural Science Foundation(2024J090).
文摘Passive daytime radiative cooling technology has demonstrated energy-saving potential during the cooling season in buildings.To address the challenge of extra heat loss during the heating season,a temperature-adaptive radiative cooler(TARC)was developed with a phase change material(PCM)cover and a multilayer daytime radiative cooler(DRC).During a warm month when the ambient temperature exceeded 20℃,the TARC system demonstrated cooling effects as static DRC,and the TARC and DRC achieved average daytime cooling temperatures of 2.5℃ and 4.5℃,respectively.However,during a colder period in December,TARC achieved an average temperature in the cooling space higher than the ambient temperature during the daytime due to the PCM cover being able to switch off infrared radiation from DRC and absorb solar radiation.To maximize energy savings in cooling and heating seasons,we established numerical models for the optimization of PCM cover and TARC.The simulation results showed that the optimized TARC could achieve a daily average temperature drop of 4.1℃ on a hot day and a temperature increase of 1.0℃ on a cold day under the same climatic conditions as the experiments.Further simulations highlight the potential of TARC systems for cross-seasonal applications.
基金supported by the NSFC(No.81801847)Natural Science Basic Research Plan in Shaanxi Province of China(No.2021JQ-200,2020JM-182,2019JQ-652).
文摘As an important way of converting mechanical energy into electric energy,a piezoelectric nanogenerator(PENG)has been widely applied in energy harvesting as well as self-powered sensors in recent years.However,its robustness and durability are still severely challenged by frequent and inevitable mechanical impacts in real application environments.Herein,a fully selfhealing PENG(FS-PENG)as a self-powered pressure sensing electronic skin is reported.The self-healing piezoelectric composite and self-healing Ag NW electrode fabricated through mixing piezoelectric PZT particles and conductive Ag NWs into self-healing polydimethylsiloxane(H-PDMS)are assembled into the sandwich structure FS-PENG.The FS-PENG could not only effectively convert external stimulation into electrical signals with a linear response to the pressure but also retain the excellent self-healing and stable sensing property after multiple cycles of cutting and self-healing process.Moreover,a self-healing pressure sensor array composed of 9 FS-PENGs was attached on the back of the human hand to mimic the human skin,and accurate monitoring of the spatial position distribution and magnitude of the pressure was successfully realized.
基金We thank the Shanghai Synchrotron Radiation Facility(SSRF)BL-11B for the in-situ XAFS measurement and the National Synchrotron Radiation Laboratory(NSRL)beamline BL11U for the soft XAS measurement.C.Y.would like to acknowledge financial support from the National Natural Science Foundation of China(No.21972172).
文摘Understanding the dynamic structural and chemical evolutions at the catalyst-electrolyte interfaces is crucial for the development of active and stable electrocatalysts.In this work,β-Li_(2)IrO_(3)is employed as a model catalyst for the oxygen evolution reaction(OER).Its elastic three-dimensional Ir-O framework enables us to investigate the Li^(+)cation dissolution-induced structure evolutions and the formation mechanism of amorphous IrO_(x)species.Electrochemical measurements by rotating ring disk electrode(RRDE)reveal that up to 60%of the measured OER current can be ascribed to catalyst degradation.A series of in-situ X-ray diffraction spectroscopy(XRD),X-ray absorption spectroscopy(XAS),and Raman spectroscopy are conducted.Structure vibration is observed with oxidation states of Ir being reduced abnormally during OER at high potentials.It’s hypothesized that the reversible proton intercalations are responsible for the Ir turn-over mechanism.Results of this work demonstrate a stable and elastic iridate structure and reveal the initial catalyst degradation behaviors during OER in acid media.
基金the Special Fund of Shanghai Municipal Economic and Informatization Commission(GYQJ-2018-2-02)。
文摘China’s accelerator driven subcritical system(ADS)development has made significant progress during the past decade.With the successful construction and operation of the international prototype of ADS superconducting proton linac,the lead-based critical/subcritical zero-power facility VENUS-II and the comprehensive thermal-hydraulic and material test facilities for LBE(lead bismuth eutectic)coolant,China is playing a pivotal role in advanced steady-state operations toward the next step,the ADS project.The China initiative Accelerator Driven System(CiADS)is the next facility for China’s ADS program,aimed to bridge the gaps between the ADS experiment and the LBE cooled subcritical reactor.The total power of the CiADS will reach 10 MW.The CiADS engineering design was approved by Chinese government in 2018.Since then,the CiADS project has been fully transferred to the construction application stage.The subcritical reactor is an important part of the whole CiADS project.Currently,a pool-type LBE cooled fast reactor is chosen as the subcritical reactor of the CiADS.Physical and thermal experiments and software development for LBE coolant were conducted simultaneously to support the design and construction of the CiADS LBEcooled subcritical reactor.Therefore,it is necessary to introduce the efforts made in China in the LBE-cooled fast reactor to provide certain supporting data and reference solutions for further design and development for ADS.Thus,the roadmap of China’s ADS,the development process of the CiADS,the important design of the current CiADS subcritical reactor,and the efforts to build the LBE-cooled fast reactor are presented.
基金This work was supported by the NSFC(Nos.51472111 and 81801847)the Fundamental Research Funds for the Central Universities(Nos.JB191407,JB181402,and lzujbky-2018-ot04)+1 种基金the National Natural Science Foundation of Shaanxi Province(No.2018JQ5153)the National Program for the Support of Top-Notch Young Professionals.
文摘In the past decades,the progress of wearable and portable electronics is quite rapid,but the power supply has been a great challenge for their practical applications.Wearable power sources,especially wearable energy-harvesting devices,provide some possible solutions for this challenge.Among various wearable energy harvesters,the high-performance fabric-based triboelectric nanogenerators(TENGs)are particularly significant.In this review paper,we first introduce the fundamentals of TENGs and their four basic working modes.Then,we will discuss the material synthesis,device design,and fabrication of fabric-based TENGs.Finally,we try to give some problems that need to be solved for the further development of TENGs.
文摘Abstract Biodegradable poly（ether-imide-ester） elasto- mers were synthesized from succinic acid, 1,4-butanediol, polyethylene glycol 1000 and N＇,N-bis（2-carboxyethyl）- pyromellitimide which was derived from pyromellitic dianhydride and glycine. The chemical structures, crystal- linities, thermal stabilities, mechanical properties, hydro- philicities and biodegradabilities of these elastomers were investigated. The hard segments of the linear aliphatic poly （ether-ester） exhibited monoclinic chain packing. Increas- ing the amount of aromatic bisimide moieties in the poly （ether-ester） reduced the crystallinity of the material and improved the thermal stability and tensile strength of the elastomers. In addition, introducing a suitable amount of aromatic bisimide moieties into the poly（ether-ester） backbones endowed the elastomers with improved biode- gradability but too many aromatic bisimide groups reduced the biodegradability of the elastomers.
基金financially supported by the National Key Research and Development Program of China(grant no.2022YFF1301602)the National Natural Science Foundation of China(grant nos.32270442,31872219,31370401,32030011,31630071,and 31772448)+1 种基金the National Key Programme of Research and Development,Ministry of Science and Technology(grant no.2016YFC0503200)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘The marine environment presents challenges for wound healing in cetaceans,despite their remarkable recovery abilities with minimal infections or complications.However,the molecular mechanism underlying this efficient wound healing remains underexplored.To better understand the molecular mechanisms behind wound healing in cetaceans,we investigated the evolutionary patterns of 37 wound healing-related genes in representative mammals.We found wound healing-related genes experience adaptive evolution in cetaceans:(1)Three extrinsic coagulation pathway-related genes-tissue factor(F3),coagulation factor VII(F7),and coagulation factor X(F10)-are subject to positive selection in cetaceans,which might promote efficient hemostasis after injury;positive selection in transforming growth factor-beta 2(TGF-β2),transforming growth factor-beta 3(TGF-β3),and platelet-derived growth factor D(PDGFD),which play immunological roles in wound healing,may help cetaceans enhance inflammatory response and tissue debridement.(2)Coagulation factor XII(F12)is the initiation factor in the intrinsic coagulation pathway.It had a premature stop codon mutation and was subjected to selective stress relaxation in cetaceans,suggesting that the early termination of F12 may help cetaceans avoid the risk of vascular blockage during diving.(3)Fibrinogen alpha chain(FGA)and FIII,which were detected to contain the specific amino acid substitutions in marine mammals,indicating similar evolutionary mechanisms might exist among marine mammals to maintain strong wound-healing ability.Thus,our research provides further impetus to study the evolution of the wound healing system in cetaceans and other marine mammals,extending knowledge of preventing coagulation disorder and atherosclerosis in humans.
