Realizing ultra-wideband absorption,desirable attenuation capability at high temperature and mechanical requirements for real-life applications remains a great challenge for microwave absorbing materials.Herein,we hav...Realizing ultra-wideband absorption,desirable attenuation capability at high temperature and mechanical requirements for real-life applications remains a great challenge for microwave absorbing materials.Herein,we have constructed a porous carbon fiber/polymethacrylimide(CP)structure for acquiring promising microwave absorption performance and withstanding both elevated temperature and high strength in a low density.Given the ability of porous structure to induce desirable impedance matching and multiple reflection,the absorption bandwidth of CP composite can reach ultra-wideband absorption of 14 GHz at room temperature and even cover the whole X-band at 473 K.Additionally,the presence of imide ring group in polymethacrylimide and hard bubble wall endows the composite with excellent heat and compressive behaviors.Besides,the lightweight of the CP composite with a density of only 110 mg cm^(−3) coupled with high compressive strength of 1.05 MPa even at 453 K also satisfies the requirements in engineering applica-tions.Compared with soft and compressible aerogel materials,we envision that the rigid porous foam absorbing material is particularly suitable for environmental extremes.展开更多
The internal oxide precipitates were supposed to be spherical in Wagner’s original theory,while the fol-lowing research demonstrated that this assumption is an exception rather than the truth,which caused deviations ...The internal oxide precipitates were supposed to be spherical in Wagner’s original theory,while the fol-lowing research demonstrated that this assumption is an exception rather than the truth,which caused deviations in the application of this theory.In this study,the internal oxide precipitates have a needle-like and a near-spherical morphology in a Fe-9Cr ferritic and a Fe-17Cr-9Ni austenitic steels after expo-sure to 600℃ deaerated steam for 600 h,respectively.The nano-to-atomic scale characterization shows that the morphology of the internal oxide precipitates is controlled by the structure of the interfaces be-tween the metal matrix and the internal oxide,while the interface structure is mainly affected by the crystallographic structure of the two phases and their orientation relationship.In addition,the internal oxide precipitation-induced volume expansion and the outward Fe diffusion-induced volume shrink oc-cur simultaneously during the oxidation process.The stress status in the internal oxidation zone(IOZ)is the competing result of the two factors,which could dynamically affect the high-temperature oxidation.The results obtained in this study suggest that there is potential to control the distribution,morphology,and interface structure of the internal oxide precipitates by selecting appropriate base metal and internal oxide-forming element,in order to obtain better high-temperature oxidation-resistant materials.展开更多
A three-dimensional finite element model of electromagnetic field and temperature field was developed to investigate the effects of induction heat of high frequency electromagnetic field on the early solidification pr...A three-dimensional finite element model of electromagnetic field and temperature field was developed to investigate the effects of induction heat of high frequency electromagnetic field on the early solidification process of molten steel.The results show that the increases of exciting current frequency make the effects of induction heat on solidification increase remarkably.Contrarily,the effects of induction heat on solidification process are weakened sharply with the increase of casting speed.Especially,when the casting speed exceeds a certain value,the effects of induction heat on solidification process are nearly negligible.展开更多
Antiferroelectric(AFE)materials are promising for the applications in advanced high-power electric and electronic devices.Among them,AgNbO_(3)(AN)-based ceramics have gained considerable attention due to their excelle...Antiferroelectric(AFE)materials are promising for the applications in advanced high-power electric and electronic devices.Among them,AgNbO_(3)(AN)-based ceramics have gained considerable attention due to their excellent energy storage performance.Herein,multiscale synergistic modulation is proposed to improve the energy storage performance of AN-based materials,whereby the multilayer structure is employed to improve the breakdown strength(Eb),and Sm/Ta doping is utilized to enhance the AFE stability.As a result,ultrahigh recoverable energy storage density(Wrec)up to 15.0 J·cm^(-3) and energy efficiency of 82.8%are obtained at 1500 kV·cm^(-3) in Sm/Ta co-doped AN multilayer ceramic capacitor(MLCC),which are superior to those of the state-of-the-art AN-based ceramic capacitor.Moreover,the discharge energy density(Wa)in direct-current charge-discharge performance reaches 9.1 J·cm^(-3),which is superior to that of the reported lead-free energy storage systems.The synergistic design of composition and multilayer structure provides an applicable method to optimize the energy storage performance in all dielectric energy storage systems.展开更多
The nickel-base alloy is one of the leading candidate materials for generation IV nuclear reactor pressure vessel.To evaluate its stability of helium damage and retention,helium ions with different energy of 80 keV an...The nickel-base alloy is one of the leading candidate materials for generation IV nuclear reactor pressure vessel.To evaluate its stability of helium damage and retention,helium ions with different energy of 80 keV and 180 keV were introduced by ion implantation to a certain dose(peak displacement damage 1-10 dpa).Then thermal desorption spectroscopy(TDS)of helium atoms was performed to discuss the helium desorption characteristic and trapping sites.The desorption peaks shift to a lower temperature with increasing dpa for both 80 keV and 180 keV irradiation,reflecting the reduced diffusion activation energy and faster diffusion within the alloy.The main release peak temperature of 180 keV helium injection is relatively higher than that of 80 keV at the same influence,which is because the irradiation damage of 180 keV,helium formation and entrapment occur deeper.The broadening of the spectra corresponds to different helium trapping sites(He-vacancies,grain boundary)and desorption mechanisms(different Hen Vm size).The helium retention amount of 80 keV is lower than that of 180 keV,and a saturation limit associated with the irradiation of 80 keV has been reached.The relatively low helium retention proves the better resistance to helium bubbles formation and helium brittleness.展开更多
While conventional nanosystems can target infected lung tissue,they cannot achieve precise cellular targeting and enhanced therapy by modulating inflammation and microbiota for effective therapy.Here,we designed a nuc...While conventional nanosystems can target infected lung tissue,they cannot achieve precise cellular targeting and enhanced therapy by modulating inflammation and microbiota for effective therapy.Here,we designed a nucleus-targeted nanosystem with adenosine triphosphate(ATP)and reactive oxygen species stimuli-response to treat pneumonia coinfected with bacteria and virus that is enhanced through inflammation and microbiota regulation.The nucleus-targeted biomimetic nanosystem was prepared through the combined bacteria-macrophage membrane and loaded hypericin and ATP-responsive dibenzyl oxalate(MMHP)subsequently.The MMHP despoiled the Mg^(2+)of intracellular cytoplasm in bacteria to achieve an effective bactericidal performance.Meanwhile,MMHP can target the cell nucleus and inhibit the H1N1 virus duplication by inhibiting the activity of nucleoprotein.MMHP possessed an immunomodulatory ability to reduce the inflammatory response and activate CD8^(+)T cells for assisted infection elimination.During the mice model,the MMHP effectively treated pneumonia coinfected with Staphylococcus aureus and H1N1 virus.Meanwhile,MMHP mediated the composition of gut microbiota to enhance the pneumonia therapy.Therefore,the dual stimuli-responsive MMHP possessed promising clinical translational potential to therapy infectious pneumonia.展开更多
We present P(TMC-co-DLLA)copolymer with the molar ratio of TMC:DLLA紏15:85 was used to systematic study of in vivo and in vitro degradation behaviors.Dense homogeneous copolymer specimens were prepared by compression ...We present P(TMC-co-DLLA)copolymer with the molar ratio of TMC:DLLA紏15:85 was used to systematic study of in vivo and in vitro degradation behaviors.Dense homogeneous copolymer specimens were prepared by compression molding method.The in vitro and in vivo degradation were,respectively,performed at simulative body condition and implanted into rat’s subcutaneous condition.Investigations were followed via physicochemical and histological analysis such as SEM,GPC,DSC,FTIR and H&E stain.The results demonstrate that copolymeric material can degrade in phosphate buffer solution(PBS)and in rat’s body,and the in vivo degradation rate is faster.Obvious decline of molecule weight and mass loss has been observed,which led to the attenuation of mechanical strength.Furthermore,apart from the hydrolysis,macrophagocytes took part in the phagocytosis in vivo,indicating that degradation rate could be regulated by the combinational mechanism.It is concluded that P(TMC-co-DLLA)copolymer is a promising candidate for tissue repair.展开更多
Chemical vapor deposition(CVD)has emerged as a promising approach for the controlled growth of graphene films with appealing scalability,controllability,and uniformity.However,the synthesis of high-quality graphene fi...Chemical vapor deposition(CVD)has emerged as a promising approach for the controlled growth of graphene films with appealing scalability,controllability,and uniformity.However,the synthesis of high-quality graphene films still suffers from low production capacity and high energy consumption in the conventional hot-wall CVD system.In contrast,owing to the different heating mode,cold-wall CVD(CW-CVD)system exhibits promising potential for the industrial-scale production,but the quality of as-received graphene remains inferior with limited domain size and high defect density.Herein,we demonstrated an efficient method for the batch synthesis of high-quality graphene films with millimeter-sized domains based on CW-CVD system.With reduced defect density and improved properties,the as-received graphene was proven to be promising candidate material for electronics and anti-corrosion application.This study provides a new insight into the quality improvement of graphene derived from CW-CVD system,and paves a new avenue for the industrial production of high-quality graphene films for potential commercial applications.展开更多
Hydrogen peroxide(H_(2)O_(2))photoproduction in seawater with metal-free photocatalysts derived from biomass materials is a green,sustainable,and ultra environmentally friendly way.However,most photocatalysts are alwa...Hydrogen peroxide(H_(2)O_(2))photoproduction in seawater with metal-free photocatalysts derived from biomass materials is a green,sustainable,and ultra environmentally friendly way.However,most photocatalysts are always corroded or poisoned in seawater,resulting in a significantly reduced catalytic performance.Here,we report the metal-free photocatalysts(RUT-1 to RUT-5)with in-situ generated carbon dots(CDs)from biomass materials(Rutin)by a simple microwave-assisted pyrolysis method.Under visible light(λ≥420 nm,81.6 mW/cm^(2)),the optimized catalyst of RUT-4 is stable and can achieve a high H_(2)O_(2)yield of 330.36μmol/L in seawater,1.78 times higher than that in normal water.New transient potential scanning(TPS)tests are developed and operated to in-situ study the H_(2)O_(2)photoproduction of RUT-4 under operation condition.RUT-4 has strong oxygen(O_(2))absorption capacity,and the O_(2)reduction rate in seawater is higher than that in water.Metal cations in seawater further promote the photo-charge separation and facilitate the photo-reduction reaction.For RUT-4,the conduction band level under operating conditions only satisfies the requirement of O_(2)reduction but not for hydrogen(H2)evolution.This work provides new insights for the in-situ study of photocatalyst under operation condition,and gives a green and sustainable path for the H_(2)O_(2)photoproduction with metal-free catalysts in seawater.展开更多
Graphene has been shown to be a promising solid lubricant to reduce friction and wear of the sliding counterparts,and currently is reported to only function below 600℃.In this study,its potential as a lubricant above...Graphene has been shown to be a promising solid lubricant to reduce friction and wear of the sliding counterparts,and currently is reported to only function below 600℃.In this study,its potential as a lubricant above 600℃ was studied using a ball-on-disc tribo-meter and a rolling mill.Friction results suggest that a reduction up to 50%can be obtained with graphene nanoplatelets(GnP)under lubricated conditions between 600 and 700℃ when compared with dry tests.and this friction reduction can last more than 3 min.At 800 and 900℃,the friction reduction is stable for 70 and 40 s,respectively,which indicates that GnP can potentially provide an effective lubrication for hot metal forming processes.Hot rolling experiments on steel strips indicate that GnP reduces the rolling force by 11%,7.4%,and 6.9%at 795,890,and 960℃,respectively.These friction reductions are attributed to the easily sheared GnP between the rubbing interfaces.A temperature higher than 600℃ will lead to the gasification of the residual graphene on the strip surface,which is believed to reduce the black contamination from traditional graphite lubricant.展开更多
A hierarchically aligned fibrin hydrogel(AFG)that possesses soft stiffness and aligned nanofiber structure has been successfully proven to facilitate neuroregeneration in vitro and in vivo.However,its potential in pro...A hierarchically aligned fibrin hydrogel(AFG)that possesses soft stiffness and aligned nanofiber structure has been successfully proven to facilitate neuroregeneration in vitro and in vivo.However,its potential in promoting nerve regeneration in large animal models that is critical for clinical translation has not been sufficiently specified.Here,the effects of AFG on directing neuroregeneration in canine hemisected T12 spinal cord injuries were explored.Histologically obvious white matter regeneration consisting of a large area of consecutive,compact and aligned nerve fibers is induced by AFG,leading to a significant motor functional restoration.The canines with AFG implantation start to stand well with their defective legs from 3 to 4 weeks postoperatively and even effortlessly climb the steps from 7 to 8 weeks.Moreover,high-resolution multi-shot diffusion tensor imaging illustrates the spatiotemporal dynamics of nerve regeneration rapidly crossing the lesion within 4 weeks in the AFG group.Our findings indicate that AFG could be a potential therapeutic vehicle for spinal cord injury by inducing rapid white matter regeneration and restoring locomotion,pointing out its promising prospect in clinic practice.展开更多
Perovskite solar cells have aroused a worldwide research upsurge in recent years due to their soaring photovoltaic performance,ease of solution processing,and low cost.The power conversion efficiency record is constan...Perovskite solar cells have aroused a worldwide research upsurge in recent years due to their soaring photovoltaic performance,ease of solution processing,and low cost.The power conversion efficiency record is constantly being broken and has recently reached 26.1%in the lab,which is comparable to the established photovoltaic technologies such as crystalline silicon,copper indium gallium selenide and cadmium telluride(CdTe)solar cells.Currently,perovskite solar cells are standing at the entrance of industrialization,where huge opportunities and risks coexist.However,towards commercialization,challenges of up-scaling,stability and lead toxicity still remain,the proper handling of which could potentially lead to the widespread adoption of perovskite solar cells as a low-cost and efficient source of renewable energy.This review gives a holistic analysis of the path towards commercialization for perovskite solar cells.A comprehensive overview of the current state-of-the-art level for perovskite solar cells and modules will be introduced first,with respect to the module efficiency,stability and current status of industrialization.We will then discuss the challenges that get in the way of commercialization and the corresponding strategies to address them,involving the upscaling,the stability and the lead toxicity issue.Insights into the future direction of commercialization of perovskite photovoltaics was also provided,including the flexible perovskite cells and modules and perovskite indoor photovoltaics.Finally,the future perspectives towards commercialization are put forward.展开更多
基金supported by the National Natural Science Foundation of China(52172091 and 52172295)the Interdisciplinary Innovation Foundation for Graduates(Nanjing University of Aeronautics and Astronautics,No.KXKCXJJ202009).
文摘Realizing ultra-wideband absorption,desirable attenuation capability at high temperature and mechanical requirements for real-life applications remains a great challenge for microwave absorbing materials.Herein,we have constructed a porous carbon fiber/polymethacrylimide(CP)structure for acquiring promising microwave absorption performance and withstanding both elevated temperature and high strength in a low density.Given the ability of porous structure to induce desirable impedance matching and multiple reflection,the absorption bandwidth of CP composite can reach ultra-wideband absorption of 14 GHz at room temperature and even cover the whole X-band at 473 K.Additionally,the presence of imide ring group in polymethacrylimide and hard bubble wall endows the composite with excellent heat and compressive behaviors.Besides,the lightweight of the CP composite with a density of only 110 mg cm^(−3) coupled with high compressive strength of 1.05 MPa even at 453 K also satisfies the requirements in engineering applica-tions.Compared with soft and compressible aerogel materials,we envision that the rigid porous foam absorbing material is particularly suitable for environmental extremes.
基金This work was financially supported by National Key Re-search and Development Program of China(No.2018YFE0116200)Shanghai Pujiang Program(No.21PJ1406400)+1 种基金EPSRC(Nos.EP/K040375/1,EP/N010868/1,and EP/R009392/1)Prof.Lefu Zhang is acknowledged for providing the samples used in this study.In-strumental Analysis Center of SJTU is also gratefully acknowledged.The atom probe facilities at the University of Oxford are funded by the EPSRC(No.EP/M022803/1).
文摘The internal oxide precipitates were supposed to be spherical in Wagner’s original theory,while the fol-lowing research demonstrated that this assumption is an exception rather than the truth,which caused deviations in the application of this theory.In this study,the internal oxide precipitates have a needle-like and a near-spherical morphology in a Fe-9Cr ferritic and a Fe-17Cr-9Ni austenitic steels after expo-sure to 600℃ deaerated steam for 600 h,respectively.The nano-to-atomic scale characterization shows that the morphology of the internal oxide precipitates is controlled by the structure of the interfaces be-tween the metal matrix and the internal oxide,while the interface structure is mainly affected by the crystallographic structure of the two phases and their orientation relationship.In addition,the internal oxide precipitation-induced volume expansion and the outward Fe diffusion-induced volume shrink oc-cur simultaneously during the oxidation process.The stress status in the internal oxidation zone(IOZ)is the competing result of the two factors,which could dynamically affect the high-temperature oxidation.The results obtained in this study suggest that there is potential to control the distribution,morphology,and interface structure of the internal oxide precipitates by selecting appropriate base metal and internal oxide-forming element,in order to obtain better high-temperature oxidation-resistant materials.
基金Item Sponsored by College Natural Science Research Project of Jiangsu Province of China(05KJD450043)
文摘A three-dimensional finite element model of electromagnetic field and temperature field was developed to investigate the effects of induction heat of high frequency electromagnetic field on the early solidification process of molten steel.The results show that the increases of exciting current frequency make the effects of induction heat on solidification increase remarkably.Contrarily,the effects of induction heat on solidification process are weakened sharply with the increase of casting speed.Especially,when the casting speed exceeds a certain value,the effects of induction heat on solidification process are nearly negligible.
基金supported by the Natural Science Foundation of Hebei Province,China(E2021201044)the National Natural Science Foundation of China(51802068 and 52073144).
文摘Antiferroelectric(AFE)materials are promising for the applications in advanced high-power electric and electronic devices.Among them,AgNbO_(3)(AN)-based ceramics have gained considerable attention due to their excellent energy storage performance.Herein,multiscale synergistic modulation is proposed to improve the energy storage performance of AN-based materials,whereby the multilayer structure is employed to improve the breakdown strength(Eb),and Sm/Ta doping is utilized to enhance the AFE stability.As a result,ultrahigh recoverable energy storage density(Wrec)up to 15.0 J·cm^(-3) and energy efficiency of 82.8%are obtained at 1500 kV·cm^(-3) in Sm/Ta co-doped AN multilayer ceramic capacitor(MLCC),which are superior to those of the state-of-the-art AN-based ceramic capacitor.Moreover,the discharge energy density(Wa)in direct-current charge-discharge performance reaches 9.1 J·cm^(-3),which is superior to that of the reported lead-free energy storage systems.The synergistic design of composition and multilayer structure provides an applicable method to optimize the energy storage performance in all dielectric energy storage systems.
基金Project supported by Special Funds for Fundamental Research Funds for Central Universities,China(Grant Nos.2018 NTST29 and 2018 NTST04)the National Natural Science Foundation of China(Grant No.61176003)+1 种基金Chinese Postdoctoral Science Foundation(Grant No.2019M650524)Guangdong Province Key Area R&D Program,China(Grant No.2019B090909002)。
文摘The nickel-base alloy is one of the leading candidate materials for generation IV nuclear reactor pressure vessel.To evaluate its stability of helium damage and retention,helium ions with different energy of 80 keV and 180 keV were introduced by ion implantation to a certain dose(peak displacement damage 1-10 dpa).Then thermal desorption spectroscopy(TDS)of helium atoms was performed to discuss the helium desorption characteristic and trapping sites.The desorption peaks shift to a lower temperature with increasing dpa for both 80 keV and 180 keV irradiation,reflecting the reduced diffusion activation energy and faster diffusion within the alloy.The main release peak temperature of 180 keV helium injection is relatively higher than that of 80 keV at the same influence,which is because the irradiation damage of 180 keV,helium formation and entrapment occur deeper.The broadening of the spectra corresponds to different helium trapping sites(He-vacancies,grain boundary)and desorption mechanisms(different Hen Vm size).The helium retention amount of 80 keV is lower than that of 180 keV,and a saturation limit associated with the irradiation of 80 keV has been reached.The relatively low helium retention proves the better resistance to helium bubbles formation and helium brittleness.
基金This work is jointly supported by the China National Funds for Distinguished Young Scientists(no.51925104)the National Natural Science Foundation of China(nos.51871162 and 52173251)+1 种基金the Central Guidance on Local Science and Technology Development Fund of Hebei Province(226Z1303G)NSFC-Guangdong Province Joint Program(key program no.U21A2084).
文摘While conventional nanosystems can target infected lung tissue,they cannot achieve precise cellular targeting and enhanced therapy by modulating inflammation and microbiota for effective therapy.Here,we designed a nucleus-targeted nanosystem with adenosine triphosphate(ATP)and reactive oxygen species stimuli-response to treat pneumonia coinfected with bacteria and virus that is enhanced through inflammation and microbiota regulation.The nucleus-targeted biomimetic nanosystem was prepared through the combined bacteria-macrophage membrane and loaded hypericin and ATP-responsive dibenzyl oxalate(MMHP)subsequently.The MMHP despoiled the Mg^(2+)of intracellular cytoplasm in bacteria to achieve an effective bactericidal performance.Meanwhile,MMHP can target the cell nucleus and inhibit the H1N1 virus duplication by inhibiting the activity of nucleoprotein.MMHP possessed an immunomodulatory ability to reduce the inflammatory response and activate CD8^(+)T cells for assisted infection elimination.During the mice model,the MMHP effectively treated pneumonia coinfected with Staphylococcus aureus and H1N1 virus.Meanwhile,MMHP mediated the composition of gut microbiota to enhance the pneumonia therapy.Therefore,the dual stimuli-responsive MMHP possessed promising clinical translational potential to therapy infectious pneumonia.
基金The authors would like to express their gratitude to the National Natural Science Foundation of China(No.31330028,31470923,31271011)National Basic Research Program of China(973 Program,No.2012CB933600),the 111 Project(B14018)+1 种基金New Century Excellent Talents in University(No.NCET-12-0856)This study is also supported by Major Basic Research Foundation of Shanghai Science and Technique Committee(14JC1490800).
文摘We present P(TMC-co-DLLA)copolymer with the molar ratio of TMC:DLLA紏15:85 was used to systematic study of in vivo and in vitro degradation behaviors.Dense homogeneous copolymer specimens were prepared by compression molding method.The in vitro and in vivo degradation were,respectively,performed at simulative body condition and implanted into rat’s subcutaneous condition.Investigations were followed via physicochemical and histological analysis such as SEM,GPC,DSC,FTIR and H&E stain.The results demonstrate that copolymeric material can degrade in phosphate buffer solution(PBS)and in rat’s body,and the in vivo degradation rate is faster.Obvious decline of molecule weight and mass loss has been observed,which led to the attenuation of mechanical strength.Furthermore,apart from the hydrolysis,macrophagocytes took part in the phagocytosis in vivo,indicating that degradation rate could be regulated by the combinational mechanism.It is concluded that P(TMC-co-DLLA)copolymer is a promising candidate for tissue repair.
基金financially supported by the National Natural Science Foundation of China(Nos.T2188101,21525310,and 52072042)the National Key R&D Program of China(No.2018YFA0703502)+1 种基金Beijing National Laboratory for Molecular Sciences(No.BNLMS-CXTD-202001)Beijing Municipal Science&Technology Commission(Nos.Z181100004818001,Z18110300480001,Z18110300480002,Z191100000819005,Z191100000819007,and Z201100008720005)。
文摘Chemical vapor deposition(CVD)has emerged as a promising approach for the controlled growth of graphene films with appealing scalability,controllability,and uniformity.However,the synthesis of high-quality graphene films still suffers from low production capacity and high energy consumption in the conventional hot-wall CVD system.In contrast,owing to the different heating mode,cold-wall CVD(CW-CVD)system exhibits promising potential for the industrial-scale production,but the quality of as-received graphene remains inferior with limited domain size and high defect density.Herein,we demonstrated an efficient method for the batch synthesis of high-quality graphene films with millimeter-sized domains based on CW-CVD system.With reduced defect density and improved properties,the as-received graphene was proven to be promising candidate material for electronics and anti-corrosion application.This study provides a new insight into the quality improvement of graphene derived from CW-CVD system,and paves a new avenue for the industrial production of high-quality graphene films for potential commercial applications.
基金supported by Natural Science Foundation of Jiangsu Province(No.BK20220028)the National Key Research and Development Program of China(Nos.2020YFA0406104 and 2020YFA0406101)+6 种基金the National Natural Science Foundation of China(Nos.52272043,52271223,52202107,and 52201269)Natural Science Foundation of Jiangsu Province(Nos.BK20210735 and 21KJB430043)the Science and Technology Development Fund,Macao SAR(No.0009/2022/ITP)Shenzhen Science and Technology Plan Project(Collaborative Innovation Special Project,SGDX20220530111203019)Collaborative Innovation Center of Suzhou Nano Science and Technologythe 111 ProjectSuzhou Key Laboratory of Functional Nano and Soft Materials.
文摘Hydrogen peroxide(H_(2)O_(2))photoproduction in seawater with metal-free photocatalysts derived from biomass materials is a green,sustainable,and ultra environmentally friendly way.However,most photocatalysts are always corroded or poisoned in seawater,resulting in a significantly reduced catalytic performance.Here,we report the metal-free photocatalysts(RUT-1 to RUT-5)with in-situ generated carbon dots(CDs)from biomass materials(Rutin)by a simple microwave-assisted pyrolysis method.Under visible light(λ≥420 nm,81.6 mW/cm^(2)),the optimized catalyst of RUT-4 is stable and can achieve a high H_(2)O_(2)yield of 330.36μmol/L in seawater,1.78 times higher than that in normal water.New transient potential scanning(TPS)tests are developed and operated to in-situ study the H_(2)O_(2)photoproduction of RUT-4 under operation condition.RUT-4 has strong oxygen(O_(2))absorption capacity,and the O_(2)reduction rate in seawater is higher than that in water.Metal cations in seawater further promote the photo-charge separation and facilitate the photo-reduction reaction.For RUT-4,the conduction band level under operating conditions only satisfies the requirement of O_(2)reduction but not for hydrogen(H2)evolution.This work provides new insights for the in-situ study of photocatalyst under operation condition,and gives a green and sustainable path for the H_(2)O_(2)photoproduction with metal-free catalysts in seawater.
基金financially supported by the National Natural Science Fund for Distinguished Young Scholars(21925506)the National Natural Science Foundation of China(U21A20331 and 81903743)+5 种基金Ningbo S&T Innovation 2025 Major Special Programme(2018B10055)CAS Key Project of Frontier Science Research(QYZDBSSW-SYS030)Ningbo Natural Science Foundation(2021J192)Ningbo Key Scientific and Technological Project(2022Z117)Ningbo Public Welfare Science and Technology Planning Project(2021S149)ZBTI Scientific Research Innovation Team(KYTD202105)。
基金This work was supported by the Australian Research Council Discovery Project(No.DP190103455)and the Linkage Project(No.LP160101871).
文摘Graphene has been shown to be a promising solid lubricant to reduce friction and wear of the sliding counterparts,and currently is reported to only function below 600℃.In this study,its potential as a lubricant above 600℃ was studied using a ball-on-disc tribo-meter and a rolling mill.Friction results suggest that a reduction up to 50%can be obtained with graphene nanoplatelets(GnP)under lubricated conditions between 600 and 700℃ when compared with dry tests.and this friction reduction can last more than 3 min.At 800 and 900℃,the friction reduction is stable for 70 and 40 s,respectively,which indicates that GnP can potentially provide an effective lubrication for hot metal forming processes.Hot rolling experiments on steel strips indicate that GnP reduces the rolling force by 11%,7.4%,and 6.9%at 795,890,and 960℃,respectively.These friction reductions are attributed to the easily sheared GnP between the rubbing interfaces.A temperature higher than 600℃ will lead to the gasification of the residual graphene on the strip surface,which is believed to reduce the black contamination from traditional graphite lubricant.
基金supported by the Chinese National Natural Science Foundation(31771056,31771052)National Key Research and Development Project(2018YFB0704304,2020YFC1107600).
文摘A hierarchically aligned fibrin hydrogel(AFG)that possesses soft stiffness and aligned nanofiber structure has been successfully proven to facilitate neuroregeneration in vitro and in vivo.However,its potential in promoting nerve regeneration in large animal models that is critical for clinical translation has not been sufficiently specified.Here,the effects of AFG on directing neuroregeneration in canine hemisected T12 spinal cord injuries were explored.Histologically obvious white matter regeneration consisting of a large area of consecutive,compact and aligned nerve fibers is induced by AFG,leading to a significant motor functional restoration.The canines with AFG implantation start to stand well with their defective legs from 3 to 4 weeks postoperatively and even effortlessly climb the steps from 7 to 8 weeks.Moreover,high-resolution multi-shot diffusion tensor imaging illustrates the spatiotemporal dynamics of nerve regeneration rapidly crossing the lesion within 4 weeks in the AFG group.Our findings indicate that AFG could be a potential therapeutic vehicle for spinal cord injury by inducing rapid white matter regeneration and restoring locomotion,pointing out its promising prospect in clinic practice.
基金the National Key Research and Development Program of China(2022YFB3803300 and 2023YFE0116800)Beijing Natural Science Foundation(IS23037).
文摘Perovskite solar cells have aroused a worldwide research upsurge in recent years due to their soaring photovoltaic performance,ease of solution processing,and low cost.The power conversion efficiency record is constantly being broken and has recently reached 26.1%in the lab,which is comparable to the established photovoltaic technologies such as crystalline silicon,copper indium gallium selenide and cadmium telluride(CdTe)solar cells.Currently,perovskite solar cells are standing at the entrance of industrialization,where huge opportunities and risks coexist.However,towards commercialization,challenges of up-scaling,stability and lead toxicity still remain,the proper handling of which could potentially lead to the widespread adoption of perovskite solar cells as a low-cost and efficient source of renewable energy.This review gives a holistic analysis of the path towards commercialization for perovskite solar cells.A comprehensive overview of the current state-of-the-art level for perovskite solar cells and modules will be introduced first,with respect to the module efficiency,stability and current status of industrialization.We will then discuss the challenges that get in the way of commercialization and the corresponding strategies to address them,involving the upscaling,the stability and the lead toxicity issue.Insights into the future direction of commercialization of perovskite photovoltaics was also provided,including the flexible perovskite cells and modules and perovskite indoor photovoltaics.Finally,the future perspectives towards commercialization are put forward.
