The asphalt pavement longitudinal crack is a common distress in cold regions,resulting from uneven deformation of the subgrade.Analysis of the correlation law between uneven deformation and crack distress is of positi...The asphalt pavement longitudinal crack is a common distress in cold regions,resulting from uneven deformation of the subgrade.Analysis of the correlation law between uneven deformation and crack distress is of positive significance for understanding the mechanism of crack initiation,and putting forward treatment measures.In view of the complexity of longitudinal crack inducement and road surface deformation,the grey relational method was used to analyze this relationship.Through long-term monitoring of the vertical deformation data of typical road sections,the vertical deformation law of the pavement surface and its deformation characteristics under the action of temperature field are analyzed.Parameters such as vertical relative deformation,vertical relative deformation rate and vertical differential deformation VDSr were constructed to describe vertical deformation characteristics.Typical distribution characteristics of longitudinal fractures and their length and distribution characteristics are also described.The grey correlation analysis theory was utilized to analyze the relationship between deformation characteristics of sections,cross sections and monitoring points and longitudinal crack characteristics(length and location).The analysis reveals a linear positive correlation or a high correlation between several indicators.This study can provide a deeper understanding of the occurrence and development mechanism of longitudinal cracks in asphalt pavement of cold areas,and give references for the research of road engineering structure,materials and distress prevention.展开更多
Engineering the morphology of nanomaterials and modifying their electronic structure are effective ways to improve their performance in electrocatalysis. Through combining the co-reduction of Pd2+ and Cu2+ precursors ...Engineering the morphology of nanomaterials and modifying their electronic structure are effective ways to improve their performance in electrocatalysis. Through combining the co-reduction of Pd2+ and Cu2+ precursors with a digestive ripening process in oleylamine, we report the synthesis of copper-palladium(Cu-Pd) alloy multicubes with rough surfaces. Benefiting from their alloy and unique rough-surfaced structure,which provides ample edge/corner and step atoms as well as the electronic coupling between Cu and Pd leading to the lower of d-band center, the rough-surfaced Cu-Pd alloy multicubes show much better electrocatalytic performance not only for formic acid oxidation but also for oxygen reduction in comparison with those of spherical Cu-Pd alloy nanoparticles and commercial Pd/C catalyst. In contrast, we confirm that the rough-surfaced Cu-Pd alloy multicubes only exhibit very low Faradaic efficiency(34.3%) for electrocatalytic conversion of carbon dioxide(CO2) to carbon monoxide(CO) due to the presence of strong competing hydrogen evolution reaction, which results in their very poor selectivity for the reduction of CO2 to CO. The findings in this study not only offer a promising strategy to produce highly effective electrocatalysts for direct formic acid fuel cells, but also enlighten the ideas to design efficient electrocatalysts for CO2 reduction.展开更多
Intense efforts have been devoted to the synthesis of heterogeneous nanocomposites consisting of chalcogenide semiconductors and noble metals,which usually exhibit enhanced properties owing to the synergistic effect b...Intense efforts have been devoted to the synthesis of heterogeneous nanocomposites consisting of chalcogenide semiconductors and noble metals,which usually exhibit enhanced properties owing to the synergistic effect between their different material domains.Tailoring the structure of the metal domains in the nanocomposites may lead to further improvements of its performance for a given application.This review therefore highlights the strategies based on a structural conversion process for the fabrication of nanocomposites consisting of chalcogenide semiconductors and noble metals with various internal structures,e.g.,hollow or cage-bell.This strategy relies on a unique inside-out diffusion phenomenon of Ag in core-shell nanoparticles with Ag residing at core or inner shell region.In the presence of sulfur or selenium precursors,the diffused Ag are converted into Ag2S or Ag2Se,which is connected with the remaining noble metal parts,forming nanocomposites consisting of silver chalcogenide and noble metal nanoparticles with hollow or cage-bell structures.We would focus on the introduction of the fundamentals,principles,electrocatalytic applications as well as perspectives of the chalcogenide semiconductor-noble metal nanocomposites derived from their core-shell precursors so as to provide the readers insights in designing efficient nanocomposites for electrocatalysis.展开更多
We developed a Gaussia luciferase (Gluc) reporter replicon of West Nile virus (WNV) and used it to quantify viral translation and RNA replication. The advantage of the Gluc replicon is that Gaussia luciferase is secre...We developed a Gaussia luciferase (Gluc) reporter replicon of West Nile virus (WNV) and used it to quantify viral translation and RNA replication. The advantage of the Gluc replicon is that Gaussia luciferase is secreted into the culture medium from cells transfected with Gluc replicon RNA, and the medium can be assayed directly for luciferase activity. Using a known Flavivirus inhibitor (NITD008), we demonstrated that the Gluc-WNV replicon could be used for antiviral screening. The Gluc-WNV-Rep will be useful for research in antiviral drug development programs, as well as for studying viral replication and pathogenesis of WNV.展开更多
Enhancing the proton conductivity of proton exchange membranes(PEMs)is essential to expand the applications of proton exchange membrane fuel cells(PEMFCs).Inspired by the proton conduction mechanism of bacteriorhodops...Enhancing the proton conductivity of proton exchange membranes(PEMs)is essential to expand the applications of proton exchange membrane fuel cells(PEMFCs).Inspired by the proton conduction mechanism of bacteriorhodopsin,cucurbit[n]urils(CB[n],where n is the number of glycoluril units,n=6,7,or 8)are introduced into sulfonated poly(ether ether ketone)(SPEEK)matrix to fabricate hybrid PEMs,employing a nature-inspired chemical engineering(NICE)methodology.The carbonyl groups of CB[n]act as proton-conducting sites,while the host–guest interaction between CB[n]and water molecules offers extra protonconducting pathways.Additionally,the molecular size of CB[n]aids in their dispersion within the SPEEK matrix,effectively bridging the unconnected proton-conducting sulfonic group domains within the SPEEK membrane.Consequently,all hybrid membranes exhibit significantly enhanced proton conductivity.Notably,the SPEEK membrane incorporating 1 wt.%CB[8](CB[8]/SPEEK-1%)demonstrates the highest proton conductivity of 198.0 mS·cm^(−1) at 60°C and 100%relative humidity(RH),which is 228%greater than that of the pure SPEEK membrane under the same conditions.Moreover,hybrid membranes exhibit superior fuel cell performance.The CB[8]/SPEEK-1%membrane achieves a maximum power density of 214 mW·cm^(−2),representing a 140%improvement over the pure SPEEK membrane(89 mW·cm^(−2))at 50°C and 100%RH.These findings serve as a foundation for constructing continuous proton-conducting pathways within membranes by utilizing supramolecular macrocycles as fuel cell electrolytes and in other applications.展开更多
Coxsackievirus A16(CA16) is one of the major causes of hand, foot, and mouth disease(HFMD) worldwide, which is a common illness that affects children. The frequent occurrence of HFMD outbreaks has become a serious pub...Coxsackievirus A16(CA16) is one of the major causes of hand, foot, and mouth disease(HFMD) worldwide, which is a common illness that affects children. The frequent occurrence of HFMD outbreaks has become a serious public health problem in Asia. Therefore, it is important to understand the pathogenesis and replication of CA16. In this study, a stable infectious c DNA clone of an epidemic strain of Coxsackievirus A16(CA16) was assembled, and subsequently a reporter virus(e GFP-CA16) was constructed by inserting the e GFP gene between the 5'-UTR and the N-terminus of VP4, with the addition of a 2A protease cleavage site(ITTLG) at its C-terminus. This was transfected into Vero cells to generate infectious recombinant viruses. The growth characteristics and plaque morphology, in vitro, in mammalian cells were found to be indistinguishable between the parental and recombinant viruses. Although the e GFP-CA16 showed smaller plaque size as compared to recombinant CA16, both were found to exhibit similar growth trends and EC50 of NITD008. In summary, this stable infectious c DNA clone should provide a valuable experimental system to study CA16 infection and host response. The e GFP-CA16 is expected to provide a powerful tool to monitor e GFP expression in infected cells and to evaluate the antiviral activity of potential antiviral agents in the treatment of CA16 infections.展开更多
The unique hot carrier-driven direct plasmonic photocatalysis of coinage metal nanomaterials(NMs)via energetic localized surface plasmon resonance(LSPR)in visible-light region has been explored in recent years.However...The unique hot carrier-driven direct plasmonic photocatalysis of coinage metal nanomaterials(NMs)via energetic localized surface plasmon resonance(LSPR)in visible-light region has been explored in recent years.However,the low photoinduced electron transfer efficiency and insufficient separation of electronhole pairs would severely preclude their widespread practical applications.Herein,we demonstrate an interesting plasmonic photocatalyst based on the construction of icosahedral(Ih)Au@C_(60) core-shell NMs,taking advantage of specific delocalizedπelectrons structure of a tight C_(60) shell and enhanced LSPR property of Ih Au core.Then,the pronounced interfacial interaction at junction region endows the obtained Au@C_(60) NMs with an outstanding photoinduced hot carrier-transmission during photocatalytic reaction,facilitating a remarkably higher(1.89 times)photocatalytic activity toward visible-light driven degradation of crystal violet(CV)dyes,as compared to bare Au NMs.Impressively,the photocatalytic activity of Ih Au@C_(60) NMs can be effectively optimized by changing the p H value of reaction solution,with the kinetic rate constant reaching the maximum value of 0.179 min^(-1) in pH011.4 solution,while 0.005 min^(-1) at pH03.0.Moreover,due to the protection of a tight C_(60) shell,the Ih Au@C_(60) NMs also possess excellent photocatalytic stability/reusability in recycling runs,holding great potential for the design of robust and high-performance plasmonic photocatalysts in repeated practical applications.展开更多
基金funded by Key Scientific Research Project of Heilongjiang Provincial Department of Transportation(Grant number MH20200828)National Natural Science Foundation of China joint fund for regional innovation and development(Grant number U20A20315)。
文摘The asphalt pavement longitudinal crack is a common distress in cold regions,resulting from uneven deformation of the subgrade.Analysis of the correlation law between uneven deformation and crack distress is of positive significance for understanding the mechanism of crack initiation,and putting forward treatment measures.In view of the complexity of longitudinal crack inducement and road surface deformation,the grey relational method was used to analyze this relationship.Through long-term monitoring of the vertical deformation data of typical road sections,the vertical deformation law of the pavement surface and its deformation characteristics under the action of temperature field are analyzed.Parameters such as vertical relative deformation,vertical relative deformation rate and vertical differential deformation VDSr were constructed to describe vertical deformation characteristics.Typical distribution characteristics of longitudinal fractures and their length and distribution characteristics are also described.The grey correlation analysis theory was utilized to analyze the relationship between deformation characteristics of sections,cross sections and monitoring points and longitudinal crack characteristics(length and location).The analysis reveals a linear positive correlation or a high correlation between several indicators.This study can provide a deeper understanding of the occurrence and development mechanism of longitudinal cracks in asphalt pavement of cold areas,and give references for the research of road engineering structure,materials and distress prevention.
基金Financial supports from the National Natural Science Foundation of China (Grant No.: 21506225, 21573240 and 21706265)Center for Mesoscience, Institute of Process Engineering, Chinese Academy of Sciences (Grant No.: COM2015A001 and MPCS-2017-A-02)
文摘Engineering the morphology of nanomaterials and modifying their electronic structure are effective ways to improve their performance in electrocatalysis. Through combining the co-reduction of Pd2+ and Cu2+ precursors with a digestive ripening process in oleylamine, we report the synthesis of copper-palladium(Cu-Pd) alloy multicubes with rough surfaces. Benefiting from their alloy and unique rough-surfaced structure,which provides ample edge/corner and step atoms as well as the electronic coupling between Cu and Pd leading to the lower of d-band center, the rough-surfaced Cu-Pd alloy multicubes show much better electrocatalytic performance not only for formic acid oxidation but also for oxygen reduction in comparison with those of spherical Cu-Pd alloy nanoparticles and commercial Pd/C catalyst. In contrast, we confirm that the rough-surfaced Cu-Pd alloy multicubes only exhibit very low Faradaic efficiency(34.3%) for electrocatalytic conversion of carbon dioxide(CO2) to carbon monoxide(CO) due to the presence of strong competing hydrogen evolution reaction, which results in their very poor selectivity for the reduction of CO2 to CO. The findings in this study not only offer a promising strategy to produce highly effective electrocatalysts for direct formic acid fuel cells, but also enlighten the ideas to design efficient electrocatalysts for CO2 reduction.
基金Financial supports from the National Natural Science Foundation of China (Grant No. 21573240)Center for Mesoscience, Institute of Process Engineering, Chinese Academy of Sciences (Grant No. COM2015A001 and MPCS-2017-A-02)
文摘Intense efforts have been devoted to the synthesis of heterogeneous nanocomposites consisting of chalcogenide semiconductors and noble metals,which usually exhibit enhanced properties owing to the synergistic effect between their different material domains.Tailoring the structure of the metal domains in the nanocomposites may lead to further improvements of its performance for a given application.This review therefore highlights the strategies based on a structural conversion process for the fabrication of nanocomposites consisting of chalcogenide semiconductors and noble metals with various internal structures,e.g.,hollow or cage-bell.This strategy relies on a unique inside-out diffusion phenomenon of Ag in core-shell nanoparticles with Ag residing at core or inner shell region.In the presence of sulfur or selenium precursors,the diffused Ag are converted into Ag2S or Ag2Se,which is connected with the remaining noble metal parts,forming nanocomposites consisting of silver chalcogenide and noble metal nanoparticles with hollow or cage-bell structures.We would focus on the introduction of the fundamentals,principles,electrocatalytic applications as well as perspectives of the chalcogenide semiconductor-noble metal nanocomposites derived from their core-shell precursors so as to provide the readers insights in designing efficient nanocomposites for electrocatalysis.
基金supported by the National Natural Science Foundation of China (grant No. 31170158 and 31000090)the '100 Talents Project' of Chinese Academy of Sciences, China (grant No. Y002171YC1)
文摘We developed a Gaussia luciferase (Gluc) reporter replicon of West Nile virus (WNV) and used it to quantify viral translation and RNA replication. The advantage of the Gluc replicon is that Gaussia luciferase is secreted into the culture medium from cells transfected with Gluc replicon RNA, and the medium can be assayed directly for luciferase activity. Using a known Flavivirus inhibitor (NITD008), we demonstrated that the Gluc-WNV replicon could be used for antiviral screening. The Gluc-WNV-Rep will be useful for research in antiviral drug development programs, as well as for studying viral replication and pathogenesis of WNV.
基金supported by the Royal Society(No.RGS\R2\202203Lan_4824933)the Engineering and Physical Sciences Research Council(Nos.EP/N509577/1,EP/T517793/1,and EP/S03305X/1).
文摘Enhancing the proton conductivity of proton exchange membranes(PEMs)is essential to expand the applications of proton exchange membrane fuel cells(PEMFCs).Inspired by the proton conduction mechanism of bacteriorhodopsin,cucurbit[n]urils(CB[n],where n is the number of glycoluril units,n=6,7,or 8)are introduced into sulfonated poly(ether ether ketone)(SPEEK)matrix to fabricate hybrid PEMs,employing a nature-inspired chemical engineering(NICE)methodology.The carbonyl groups of CB[n]act as proton-conducting sites,while the host–guest interaction between CB[n]and water molecules offers extra protonconducting pathways.Additionally,the molecular size of CB[n]aids in their dispersion within the SPEEK matrix,effectively bridging the unconnected proton-conducting sulfonic group domains within the SPEEK membrane.Consequently,all hybrid membranes exhibit significantly enhanced proton conductivity.Notably,the SPEEK membrane incorporating 1 wt.%CB[8](CB[8]/SPEEK-1%)demonstrates the highest proton conductivity of 198.0 mS·cm^(−1) at 60°C and 100%relative humidity(RH),which is 228%greater than that of the pure SPEEK membrane under the same conditions.Moreover,hybrid membranes exhibit superior fuel cell performance.The CB[8]/SPEEK-1%membrane achieves a maximum power density of 214 mW·cm^(−2),representing a 140%improvement over the pure SPEEK membrane(89 mW·cm^(−2))at 50°C and 100%RH.These findings serve as a foundation for constructing continuous proton-conducting pathways within membranes by utilizing supramolecular macrocycles as fuel cell electrolytes and in other applications.
基金supported by the Science and Technology Plan Projects of Wuhan (grant No. 2013060501010157)
文摘Coxsackievirus A16(CA16) is one of the major causes of hand, foot, and mouth disease(HFMD) worldwide, which is a common illness that affects children. The frequent occurrence of HFMD outbreaks has become a serious public health problem in Asia. Therefore, it is important to understand the pathogenesis and replication of CA16. In this study, a stable infectious c DNA clone of an epidemic strain of Coxsackievirus A16(CA16) was assembled, and subsequently a reporter virus(e GFP-CA16) was constructed by inserting the e GFP gene between the 5'-UTR and the N-terminus of VP4, with the addition of a 2A protease cleavage site(ITTLG) at its C-terminus. This was transfected into Vero cells to generate infectious recombinant viruses. The growth characteristics and plaque morphology, in vitro, in mammalian cells were found to be indistinguishable between the parental and recombinant viruses. Although the e GFP-CA16 showed smaller plaque size as compared to recombinant CA16, both were found to exhibit similar growth trends and EC50 of NITD008. In summary, this stable infectious c DNA clone should provide a valuable experimental system to study CA16 infection and host response. The e GFP-CA16 is expected to provide a powerful tool to monitor e GFP expression in infected cells and to evaluate the antiviral activity of potential antiviral agents in the treatment of CA16 infections.
基金financially supported by the National Natural Science Foundation of China(NSFC)(Nos.11905115,11575102)the Shandong Jianzhu University XNBS Foundation(No.1608)the Fundamental Research Fund of Shandong University(No.2018JC022)。
文摘The unique hot carrier-driven direct plasmonic photocatalysis of coinage metal nanomaterials(NMs)via energetic localized surface plasmon resonance(LSPR)in visible-light region has been explored in recent years.However,the low photoinduced electron transfer efficiency and insufficient separation of electronhole pairs would severely preclude their widespread practical applications.Herein,we demonstrate an interesting plasmonic photocatalyst based on the construction of icosahedral(Ih)Au@C_(60) core-shell NMs,taking advantage of specific delocalizedπelectrons structure of a tight C_(60) shell and enhanced LSPR property of Ih Au core.Then,the pronounced interfacial interaction at junction region endows the obtained Au@C_(60) NMs with an outstanding photoinduced hot carrier-transmission during photocatalytic reaction,facilitating a remarkably higher(1.89 times)photocatalytic activity toward visible-light driven degradation of crystal violet(CV)dyes,as compared to bare Au NMs.Impressively,the photocatalytic activity of Ih Au@C_(60) NMs can be effectively optimized by changing the p H value of reaction solution,with the kinetic rate constant reaching the maximum value of 0.179 min^(-1) in pH011.4 solution,while 0.005 min^(-1) at pH03.0.Moreover,due to the protection of a tight C_(60) shell,the Ih Au@C_(60) NMs also possess excellent photocatalytic stability/reusability in recycling runs,holding great potential for the design of robust and high-performance plasmonic photocatalysts in repeated practical applications.
