Sub-nanowires(SNWs),∼1 nm in thickness,possess an inorganic skeleton but display characteristics akin to those of carbon–carbon backbone polymers,such as flexibility,adhesion,gelation,self-assembling behaviors,and s...Sub-nanowires(SNWs),∼1 nm in thickness,possess an inorganic skeleton but display characteristics akin to those of carbon–carbon backbone polymers,such as flexibility,adhesion,gelation,self-assembling behaviors,and shear-thinning properties.Despite this,the underlying mechanism for these polymer-like properties remains unexplored.This study investigates the origin of SNWs’unique behavior from three distinct perspectives.Utilizing single-molecule force spectroscopy,we quantitatively measure the persistence lengths of SNWs,which provide a measure of flexibility.In addition,we evaluate the macroscopic mechanical properties of SNW materials,including the strength of electrospun fibers and gelation in solutions.Finally,we apply molecular dynamics to simulate the behaviors of SNWs under elongating and rotating conditions.The three perspectives mentioned above in the study collectively provide evidence for the structure-activity relationship of nanomaterials:a freely rotated backbone results in a flexible SNW,which is inclined to bend and entangle to form gels in solutions.Conversely,a stiff backbone leads to a rigid SNW,which induces strong fibers.展开更多
Sub-1 nm nanowires(SNWs) can not only be processed like polymers due to their polymer-analogue properties but also show multifunctions owing to their well-manipulated compositions and structures. Rationally designed a...Sub-1 nm nanowires(SNWs) can not only be processed like polymers due to their polymer-analogue properties but also show multifunctions owing to their well-manipulated compositions and structures. Rationally designed and engineered multicomponent heterostructure SNWs can further enhance their multifunction performance while it is very challenging to achieve such SNWs at sub-nanoscale.Herein, we synthesized Bi_(2)O_(3)-polyoxometalate heterostructure SNWs(PMB SNWs), and fabricated super-aligned PMB SNWs films(S-PMB SNWs films), which can serve as interlayers to efficiently suppress lithium polysulfide(LPS)shuttling, intrinsically promote the redox kinetics of the LPS conversion and substantially protect the Li anode. The lithium-sulfur(Li-S) battery with the S-PMB SNWs film as the interlayer showcases an ultralow capacity decay rate with 0.013% per cycle over 850 cycles. This study demonstrates the potential of heterostructure SNWs to improve the performance of Li-S batteries.展开更多
Photoresponsive materials have been widely used in sensing,bioimaging,molecular switches,information storage,and encryption nowadays.Although a large amount of photoresponsive materials have been reported,the construc...Photoresponsive materials have been widely used in sensing,bioimaging,molecular switches,information storage,and encryption nowadays.Although a large amount of photoresponsive materials have been reported,the construction of these smart materials into precisely prescribed complex 3D geometries is rarely studied.Here we designed a novel photoresponsive material methyl methacrylate containing triphenylethylene(TrPEF_(2)-MA)that can be directly used for digital light processing(DLP)3D printing.Based on TrPEF_(2)-MA,a series of photoresponsive 3D structures with reversible color switching under ultraviolet/visible light irradiations were fabricated.These complex photoresponsive 3D structures show high resolutions(50μm),excellent repeatability(25 cycles without fatigue),and tunable saturate color degrees.Multicomponent DLP 3D printing processes were also carried out to demonstrate their great properties in information hiding and information-carrying properties.This design strategy for constructing photoresponsive 3D structures is attractive in the area of adaptive camouflage,information hiding,information storage,and flexible electronics.展开更多
Coronavirus disease 2019(COVID-19),which is caused by severe acute respiratory syndrome coronavirus-2(SARS-CoV-2),has spread around the world.However,approaches to distinguish COVID-19 from pneumonia caused by other p...Coronavirus disease 2019(COVID-19),which is caused by severe acute respiratory syndrome coronavirus-2(SARS-CoV-2),has spread around the world.However,approaches to distinguish COVID-19 from pneumonia caused by other pathogens have not yet been reported.We retrospectively analyzed the clinical data of 97 children with probable COVID-19.A total of 13(13.4%)patients were confirmed positive for SARS-CoV-2 infection by nucleic acid RT-PCR testing,and 41(42.3%)patients were found to be infected with other pathogens.Notably,no pathogen was detected in 43(44.3%)patients.Among all patients,25(25.8%)had familial cluster exposure history,and 52(53.6%)had one or more coexisting conditions.Fifteen(15.5%)patients were admitted or transferred to the PICU.In the 11 confirmed COVID-19 cases,5(45.5%)and 7(63.6%)were positive for IgM and IgG against SARS-CoV-2,respectively.In 22 patients with suspected COVID-19,1(4.5%)was positive for IgG but negative for IgM.The most frequently detected pathogen was Mycoplasma pneumonia(29,29.9%).One patient with confirmed COVID-19 died.Our results strongly indicated that the detection of asymptomatic COVID-19 or coexisting conditions must be strengthened in pediatric patients.These cases may be difficult to diagnose as COVID-19 unless etiologic analysis is conducted.A serologic test can be a useful adjunctive diagnostic tool in cases where SARS-CoV-2 infection is highly suspected but the nucleic acid test is negative.展开更多
Tailoring atomic structures of noblemetal nanomaterials with size close to single-unit cell range is essential in both fundamental researchand applications,including their development into high catalytic performance m...Tailoring atomic structures of noblemetal nanomaterials with size close to single-unit cell range is essential in both fundamental researchand applications,including their development into high catalytic performance materials in renewable,green energy conversions,devices for energy storage,and as biosensors for environmental pollutants.However,several strategies used in fabricating these materials still impose enormous challenges,arising from lack of even size distribution,shape uniformity,and controlled composition,which are critical in determining their specific activities and efficiencies.Herein,we report a facile approach for preparing sub-nano-thick palladium nanobelt-based(PdNB)materials.Then we rationalized the formation mechanism of such highly anisotropic structures by morphology-related thermodynamic and kinetic analysis.Moreover,we investigated if electrocatalysis performance of these NB-basedmaterialswere enhanced.Thepalladium(Pd)NBs featured a thickness of∼0.9-1.2 nm and width of 5-18nmwith length extending to severalmicrometers[denoted as Pd(0.9)],or a thickness of∼0.7-0.9 nm and width of 2.5-6 nmwith length of several hundreds of nanometers[denoted as Pd(0.7)].According to our theoretical analysis,one-dimensional(1D)growth encountered almost no energy barrier at optimal reaction conditions,whereas the growth of Pd nanostructures with other dimensions confronted high barriers,indicating that it was plausible to prepare 1D structures with sizes close to single-unit cells.Also,platinum(Pt)could be successfully doped into the Pd(0.9)NBs through a galvanic epitaxial growth,forming edge-Pt-enriched Pd NBs(eePtPd NBs).Further,electron transfer from Pd to Pt imparted the eePtPd NBs with high hydrogen evolution reaction(HER)activity.The eePtPd NBs showed a 3.5 and 1.8 times higher in exchange current density and mass activity(at−0.1 V),respectively,compared to those of Pt catalysts in perchloric acid(HClO_(4))solutions.Finally,the NBs all showed high activity toward ethanol and formic acid oxidation reactions.Our current work aids in gaining insights into tailoring Pd nanostructures at an atomic level and provides Pd sub-nanometric 1D structures for further research.Moreover,our morphology-related thermodynamic and kinetic analysis extend our understanding of the control of nanostructure morphology and might shed light on the precision of designing specific morphologies of noble metal nanocrystal structures.展开更多
CONSPECTUS:Size is one of the most important issues in materials science.Sizes of conventional nanomaterials are usually one to one hundred nanometers and,according to size effect,nanomaterials usually exhibit differe...CONSPECTUS:Size is one of the most important issues in materials science.Sizes of conventional nanomaterials are usually one to one hundred nanometers and,according to size effect,nanomaterials usually exhibit different optical,electrical,magnetic,thermal,and catalytic properties compared with bulk materials.As the important transition from atomic scale to nanoscale,subnanometer scale is a critical feature size in materials science.With the size of nanomaterials decreasing to subnanometer scale,they further show some distinctive properties.展开更多
Photodeformable materials are a class of molecules that can convert photon energy into mechanical energy,which have attracted tremendous attention in the last few decades.Owing to their unique photoinduced deformable ...Photodeformable materials are a class of molecules that can convert photon energy into mechanical energy,which have attracted tremendous attention in the last few decades.Owing to their unique photoinduced deformable properties,including fast lightresponse and diverse mechanical behaviors,photodeformable materials have exhibited great potential in many practical applications such as actuators,photoswitches,artificial muscles,and bioimaging.In this review,we sort out the current state of photodeformable crystals and classify them into six categories by molecular structures:diarylethenes,azobenzenes,anthracenes,olefins,triarylethylenes,and other systems.Three distinct light-responsive mechanisms,photocyclization,trans-cis isomerization,and photodimerization,are revealed to play significant roles in the molecular photodeformation.Their corresponding photodeformable behaviors such as twisting,bending,hopping,bursting,and curling,as well as the potential applications,are also discussed.Furthermore,the challenges and prospective development directions of photodeformable crystals are highlighted.展开更多
Photodeformable materials are a class of molecules that can convert photon energy into mechanical energy,which have attracted tremendous attention in the last few decades.Owing to their unique photoinduced deformable ...Photodeformable materials are a class of molecules that can convert photon energy into mechanical energy,which have attracted tremendous attention in the last few decades.Owing to their unique photoinduced deformable properties,including fast lightresponse and diverse mechanical behaviors,photodeformable materials have exhibited great potential in many practical applications such as actuators,photoswitches,artificial muscles,and bioimaging.In this review,we sort out the current state of photodeformable crystals and classify them into six categories by molecular structures:diarylethenes,azobenzenes,anthracenes,olefins,triarylethylenes,and other systems.Three distinct light-responsive mechanisms,photocyclization,trans-cis isomerization,and photodimerization,are revealed to play significant roles in the molecular photodeformation.Their corresponding photodeformable behaviors such as twisting,bending,hopping,bursting,and curling,as well as the potential applications,are also discussed.Furthermore,the challenges and prospective development directions of photodeformable crystals are highlighted.展开更多
基金supported by the National Key R&D Program of China(grant no.2017YFA0700101)NSFC(grant nos.22241502,22035004,and 92261118)+1 种基金Young Elite Scientist Sponsorship Program by CAST(grant no.2022QNRC001)the XPLORER PRIZE.
文摘Sub-nanowires(SNWs),∼1 nm in thickness,possess an inorganic skeleton but display characteristics akin to those of carbon–carbon backbone polymers,such as flexibility,adhesion,gelation,self-assembling behaviors,and shear-thinning properties.Despite this,the underlying mechanism for these polymer-like properties remains unexplored.This study investigates the origin of SNWs’unique behavior from three distinct perspectives.Utilizing single-molecule force spectroscopy,we quantitatively measure the persistence lengths of SNWs,which provide a measure of flexibility.In addition,we evaluate the macroscopic mechanical properties of SNW materials,including the strength of electrospun fibers and gelation in solutions.Finally,we apply molecular dynamics to simulate the behaviors of SNWs under elongating and rotating conditions.The three perspectives mentioned above in the study collectively provide evidence for the structure-activity relationship of nanomaterials:a freely rotated backbone results in a flexible SNW,which is inclined to bend and entangle to form gels in solutions.Conversely,a stiff backbone leads to a rigid SNW,which induces strong fibers.
基金supported by the Ministry of Science and Technology of China (2017YFA0700101, 2016YFA0202801 and 2016YBF0100100)China Postdoctoral Science Foundation funded project (2020TQ0164)+7 种基金the Shuimu Tsinghua Scholar Programthe National Natural Science Foundation of China (22035004, 51872283 and 21805273)Liaoning Bai Qian Wan Talents ProgramLiaoning Revitalization Talents Program (XLYC1807153)Dalian Institute of Chemical Physics (DICP ZZBS201708, DICP ZZBS201802 and DICP I202032)DICP&QIBEBT (DICP&QIBEBT UN201702)Dalian National Laboratory For Clean Energy (DNL) Cooperation FundCAS (DNL180310, DNL180308, DNL201912 and DNL201915)。
文摘Sub-1 nm nanowires(SNWs) can not only be processed like polymers due to their polymer-analogue properties but also show multifunctions owing to their well-manipulated compositions and structures. Rationally designed and engineered multicomponent heterostructure SNWs can further enhance their multifunction performance while it is very challenging to achieve such SNWs at sub-nanoscale.Herein, we synthesized Bi_(2)O_(3)-polyoxometalate heterostructure SNWs(PMB SNWs), and fabricated super-aligned PMB SNWs films(S-PMB SNWs films), which can serve as interlayers to efficiently suppress lithium polysulfide(LPS)shuttling, intrinsically promote the redox kinetics of the LPS conversion and substantially protect the Li anode. The lithium-sulfur(Li-S) battery with the S-PMB SNWs film as the interlayer showcases an ultralow capacity decay rate with 0.013% per cycle over 850 cycles. This study demonstrates the potential of heterostructure SNWs to improve the performance of Li-S batteries.
基金The authors gratefully acknowledge the financial support from the National Natural Science Foundation of China(51703253)the Fundamental Research Funds for the Central Universities,Key Research and Development Program of Shaanxi Province(2020GXLH-Z-010)+6 种基金the Chongqing Science and Technology Fund(cstc2020jcyj-msxmX0931)the Guangdong Basic and Applied Basic Research Foundation(2021A1515010633)the Ningbo Natural Science Foundation(202003N4060)the National Aerospace Science Foundation of China(2020Z073053007)the China Postdoctoral Science Foundation(2021M692624)the Natural Science Basic Research Program of Shaanxi Province(2022JQ-583)the Henan Key Laboratory of Special Protective Materials(Grant No.SZKFKT202106).
文摘Photoresponsive materials have been widely used in sensing,bioimaging,molecular switches,information storage,and encryption nowadays.Although a large amount of photoresponsive materials have been reported,the construction of these smart materials into precisely prescribed complex 3D geometries is rarely studied.Here we designed a novel photoresponsive material methyl methacrylate containing triphenylethylene(TrPEF_(2)-MA)that can be directly used for digital light processing(DLP)3D printing.Based on TrPEF_(2)-MA,a series of photoresponsive 3D structures with reversible color switching under ultraviolet/visible light irradiations were fabricated.These complex photoresponsive 3D structures show high resolutions(50μm),excellent repeatability(25 cycles without fatigue),and tunable saturate color degrees.Multicomponent DLP 3D printing processes were also carried out to demonstrate their great properties in information hiding and information-carrying properties.This design strategy for constructing photoresponsive 3D structures is attractive in the area of adaptive camouflage,information hiding,information storage,and flexible electronics.
基金This study was supported by the National Natural Science Foundation of China(No.81741099).
文摘Coronavirus disease 2019(COVID-19),which is caused by severe acute respiratory syndrome coronavirus-2(SARS-CoV-2),has spread around the world.However,approaches to distinguish COVID-19 from pneumonia caused by other pathogens have not yet been reported.We retrospectively analyzed the clinical data of 97 children with probable COVID-19.A total of 13(13.4%)patients were confirmed positive for SARS-CoV-2 infection by nucleic acid RT-PCR testing,and 41(42.3%)patients were found to be infected with other pathogens.Notably,no pathogen was detected in 43(44.3%)patients.Among all patients,25(25.8%)had familial cluster exposure history,and 52(53.6%)had one or more coexisting conditions.Fifteen(15.5%)patients were admitted or transferred to the PICU.In the 11 confirmed COVID-19 cases,5(45.5%)and 7(63.6%)were positive for IgM and IgG against SARS-CoV-2,respectively.In 22 patients with suspected COVID-19,1(4.5%)was positive for IgG but negative for IgM.The most frequently detected pathogen was Mycoplasma pneumonia(29,29.9%).One patient with confirmed COVID-19 died.Our results strongly indicated that the detection of asymptomatic COVID-19 or coexisting conditions must be strengthened in pediatric patients.These cases may be difficult to diagnose as COVID-19 unless etiologic analysis is conducted.A serologic test can be a useful adjunctive diagnostic tool in cases where SARS-CoV-2 infection is highly suspected but the nucleic acid test is negative.
基金This work was supported by the National Key R&D Program of China(2017YFA0700101 and 2016YFA0202801)NSFC(21431003 and 21521091).
文摘Tailoring atomic structures of noblemetal nanomaterials with size close to single-unit cell range is essential in both fundamental researchand applications,including their development into high catalytic performance materials in renewable,green energy conversions,devices for energy storage,and as biosensors for environmental pollutants.However,several strategies used in fabricating these materials still impose enormous challenges,arising from lack of even size distribution,shape uniformity,and controlled composition,which are critical in determining their specific activities and efficiencies.Herein,we report a facile approach for preparing sub-nano-thick palladium nanobelt-based(PdNB)materials.Then we rationalized the formation mechanism of such highly anisotropic structures by morphology-related thermodynamic and kinetic analysis.Moreover,we investigated if electrocatalysis performance of these NB-basedmaterialswere enhanced.Thepalladium(Pd)NBs featured a thickness of∼0.9-1.2 nm and width of 5-18nmwith length extending to severalmicrometers[denoted as Pd(0.9)],or a thickness of∼0.7-0.9 nm and width of 2.5-6 nmwith length of several hundreds of nanometers[denoted as Pd(0.7)].According to our theoretical analysis,one-dimensional(1D)growth encountered almost no energy barrier at optimal reaction conditions,whereas the growth of Pd nanostructures with other dimensions confronted high barriers,indicating that it was plausible to prepare 1D structures with sizes close to single-unit cells.Also,platinum(Pt)could be successfully doped into the Pd(0.9)NBs through a galvanic epitaxial growth,forming edge-Pt-enriched Pd NBs(eePtPd NBs).Further,electron transfer from Pd to Pt imparted the eePtPd NBs with high hydrogen evolution reaction(HER)activity.The eePtPd NBs showed a 3.5 and 1.8 times higher in exchange current density and mass activity(at−0.1 V),respectively,compared to those of Pt catalysts in perchloric acid(HClO_(4))solutions.Finally,the NBs all showed high activity toward ethanol and formic acid oxidation reactions.Our current work aids in gaining insights into tailoring Pd nanostructures at an atomic level and provides Pd sub-nanometric 1D structures for further research.Moreover,our morphology-related thermodynamic and kinetic analysis extend our understanding of the control of nanostructure morphology and might shed light on the precision of designing specific morphologies of noble metal nanocrystal structures.
基金supported by the National Key R&D Program of China(2017YFA0700101)and the NSFC(22035004)Beijing Institute of Technology Research Fund Program for Young ScholarsBeijing Institute of Technology Teli Young Fellow program.
文摘CONSPECTUS:Size is one of the most important issues in materials science.Sizes of conventional nanomaterials are usually one to one hundred nanometers and,according to size effect,nanomaterials usually exhibit different optical,electrical,magnetic,thermal,and catalytic properties compared with bulk materials.As the important transition from atomic scale to nanoscale,subnanometer scale is a critical feature size in materials science.With the size of nanomaterials decreasing to subnanometer scale,they further show some distinctive properties.
基金The authors gratefully acknowledge the financial support from the NSF of China(51703253)Fundamental Research Funds for the Central Universities,Key Research and Development Program of Shaanxi Province(2020GXLH-Z-010)+7 种基金Shaanxi Science and Technology Fund(2020JQ-168)Pearl River Nova Program of Guangzhou(201906010091)Chongqing Science and Technology Fund(cstc2020jcyjmsxmX0931)Guangdong Basic and Applied Basic Research Foundation(2021A1515010633)Ningbo Natural Science Foundation(202003N4060)China Postdoctoral Science Foundation(2021M692624)Henan Key Laboratory of Special Protective Materials(SZKFJJ202001)National Aerospace Science Foundation of China(2020Z073053007).
文摘Photodeformable materials are a class of molecules that can convert photon energy into mechanical energy,which have attracted tremendous attention in the last few decades.Owing to their unique photoinduced deformable properties,including fast lightresponse and diverse mechanical behaviors,photodeformable materials have exhibited great potential in many practical applications such as actuators,photoswitches,artificial muscles,and bioimaging.In this review,we sort out the current state of photodeformable crystals and classify them into six categories by molecular structures:diarylethenes,azobenzenes,anthracenes,olefins,triarylethylenes,and other systems.Three distinct light-responsive mechanisms,photocyclization,trans-cis isomerization,and photodimerization,are revealed to play significant roles in the molecular photodeformation.Their corresponding photodeformable behaviors such as twisting,bending,hopping,bursting,and curling,as well as the potential applications,are also discussed.Furthermore,the challenges and prospective development directions of photodeformable crystals are highlighted.
基金the financial support from the NSF of China(51703253)Fundamental Research Funds for the Central Universities,Key Research and Development Program of Shaanxi Province(2020GXLH-Z-010)+7 种基金Shaanxi Science and Technology Fund(2020JQ-168)Pearl River Nova Program of Guangzhou(201906010091)Chongqing Science and Technology Fund(cstc2020jcyjmsxmX0931)Guangdong Basic and Applied Basic Research Foundation(2021A1515010633)Ningbo Natural Science Foundation(202003N4060)China Postdoctoral Science Foundation(2021M692624)Henan Key Laboratory of Special Protective Materials(SZKFJJ202001)National Aerospace Science Foundation of China(2020Z073053007).
文摘Photodeformable materials are a class of molecules that can convert photon energy into mechanical energy,which have attracted tremendous attention in the last few decades.Owing to their unique photoinduced deformable properties,including fast lightresponse and diverse mechanical behaviors,photodeformable materials have exhibited great potential in many practical applications such as actuators,photoswitches,artificial muscles,and bioimaging.In this review,we sort out the current state of photodeformable crystals and classify them into six categories by molecular structures:diarylethenes,azobenzenes,anthracenes,olefins,triarylethylenes,and other systems.Three distinct light-responsive mechanisms,photocyclization,trans-cis isomerization,and photodimerization,are revealed to play significant roles in the molecular photodeformation.Their corresponding photodeformable behaviors such as twisting,bending,hopping,bursting,and curling,as well as the potential applications,are also discussed.Furthermore,the challenges and prospective development directions of photodeformable crystals are highlighted.
