The aperture of natural rock fractures significantly affects the deformation and strength properties of rock masses,as well as the hydrodynamic properties of fractured rock masses.The conventional measurement methods ...The aperture of natural rock fractures significantly affects the deformation and strength properties of rock masses,as well as the hydrodynamic properties of fractured rock masses.The conventional measurement methods are inadequate for collecting data on high-steep rock slopes in complex mountainous regions.This study establishes a high-resolution three-dimensional model of a rock slope using unmanned aerial vehicle(UAV)multi-angle nap-of-the-object photogrammetry to obtain edge feature points of fractures.Fracture opening morphology is characterized using coordinate projection and transformation.Fracture central axis is determined using vertical measuring lines,allowing for the interpretation of aperture of adaptive fracture shape.The feasibility and reliability of the new method are verified at a construction site of a railway in southeast Tibet,China.The study shows that the fracture aperture has a significant interval effect and size effect.The optimal sampling length for fractures is approximately 0.5e1 m,and the optimal aperture interpretation results can be achieved when the measuring line spacing is 1%of the sampling length.Tensile fractures in the study area generally have larger apertures than shear fractures,and their tendency to increase with slope height is also greater than that of shear fractures.The aperture of tensile fractures is generally positively correlated with their trace length,while the correlation between the aperture of shear fractures and their trace length appears to be weak.Fractures of different orientations exhibit certain differences in their distribution of aperture,but generally follow the forms of normal,log-normal,and gamma distributions.This study provides essential data support for rock and slope stability evaluation,which is of significant practical importance.展开更多
Spun-bond non-woven fabrics(NWFs)made of porous C-shaped polypropylene fibers were applied in rapid oil absorption and effective on-line oil spillage monitoring.It is of great interest to further optimize the absorpti...Spun-bond non-woven fabrics(NWFs)made of porous C-shaped polypropylene fibers were applied in rapid oil absorption and effective on-line oil spillage monitoring.It is of great interest to further optimize the absorption properties of these materials by tuning their preparation parameters as well as characterize them with theoretical models.In this paper,effects of die shape,diluent composition(mixtures of dibutyl and dioctyl phthalate),and drawing speed on their porous structure and oil-absorbing performance were systematically investigated and characterized based on two novel concepts,i.e.,the equivalent capillary tube pore radius and the kinetic pore tortuosity(barrier to access)derived from the simplest capillary tube liquid-filling model.The use of higher dibutyl phthalate fractions under faster drawing speeds resulted in the formation of larger and more connected inner filament sub-micron pores.Three stages of tube filling relating to inter-filament large pores,medium pores close to bonding points,and inner filament small pores were observed in the spun-bond NWFs.Continuous oil recovery rates of 986 L·m^(-2)·h^(-1) with an oil/water selectivity of 6.4 were achieved in dynamic skimming experiments using simulated spilled oil.展开更多
Single atom catalyst is of great importance for the oxygen reduction reaction(ORR).However,facile preparation of single atom catalyst without using well-designed precursors or labor-intensive acid leaching remains an ...Single atom catalyst is of great importance for the oxygen reduction reaction(ORR).However,facile preparation of single atom catalyst without using well-designed precursors or labor-intensive acid leaching remains an urgent challenge.Herein,a simple pyrolysis of Fe3+-loaded mesoporous phenolic resin(mPF)-melamine precursor is used to prepare the single atom iron-anchored N-doped mesoporous graphitic carbon nanospheres(Fe/N-MGN).Investigation of the synthesis reveals the appropriate Fe-assisted catalysis effect and mPF template effect,which not only spurs the highly graphitic porous framework of Fe/N-MGN with plentiful pyridinic N/graphitic N,but also assures the dispersed single atom Fe anchoring without elaborated procedures.As a result,the as-synthesized Fe/N-MGN demonstrates high catalytic activity,good durability and excellent methanol tolerance for ORR.This work promises a facile method to regulate the graphitic carbon growth and single atom Fe loading for the highly efficient electrocatalysis.展开更多
Labor-saving preparation of highly active electrocatalysts for alcohols oxidation, especially for the ethylene glycol and glycerol electrooxidation is of great importance for the development of fuel cells. Herein, mes...Labor-saving preparation of highly active electrocatalysts for alcohols oxidation, especially for the ethylene glycol and glycerol electrooxidation is of great importance for the development of fuel cells. Herein, mesocellular graphene foam (MGF) constructed by ultrathin nanosheets were prepared using lamellar MCM-22 zeolite as template and then ultra-small Pd NPs were facile grew on it via the stabilizer-free synthesis. Detailed characterizations showed that the obtained Pd/MGF had large surface area, hierarchical porous architecture, semi-graphitic framework and dispersed Pd NPs an chori ng. Electrochemical measurements dem on strated that Pd/MGF possessed the higher catalytic activity (1.7-2.9 fold higher) and stability for the different alcohols electrooxidation, especially for the ethylene glycol and glycerol electrooxidation in the alkaline solution, than the commercial Pd/C (10 wt.%) catalyst. Reaction kinetics analysis revealed the expanded diffusion-controlled process of Pd/MGF as compared to Pd/C. These findings promised a potential electrocatalyst for direct alcohol fuel cells (DAFC), especially for the direct ethylene glycol or glycerol fuel cells with high energy density.展开更多
Batch experiments were conducted to study the short-term biological effects of rare earth ions(La^(3+),Ce^(3+))and their mixture on the nitrogen removal in a sequencing batch reactor(SBR).The data showed that higher N...Batch experiments were conducted to study the short-term biological effects of rare earth ions(La^(3+),Ce^(3+))and their mixture on the nitrogen removal in a sequencing batch reactor(SBR).The data showed that higher NH4+–N removal rate,total inorganic nitrogen removal efficiency,and denitrification efficiency were achieved at lower concentrations of rare earth elements(REEs)(<1 mg/L).In the first hour of the aeration stage of SBR,the presence of REEs increased the total inorganic nitrogen removal efficiency and NH4+–N removal effi-ciency by 15.7%and 10%–15%,respectively.When the concentrations of REEs were higher than 1 mg/L,the total inorganic nitrogen removal efficiency decreased,and nitrate was found to accumulate in the effluent.When the concentrations of REEs was up to 50.0 mg/L,the total inorganic nitrogen removal efficiency was less than 30%of the control efficiency with a high level of nitrate.Lower concentrations of REEs were found to accelerate the nitrogen conversion and removal in SBR.展开更多
Changes in gene expression are associated with the evolution of pesticide resis-tance in arthropods.In this study,transcriptome sequencing was performed in 3 different resistance levels(low,L;medium,M;and high,H)of cy...Changes in gene expression are associated with the evolution of pesticide resis-tance in arthropods.In this study,transcriptome sequencing was performed in 3 different resistance levels(low,L;medium,M;and high,H)of cyflumetofen-resistant strain(YN-CyR).A total of 1685 genes,including 97 detoxification enzyme genes,were upregulated in all 3 stages,of which 192 genes,including 11 detoxification enzyme genes,showed a continuous increase in expression level with resistance development(L to H).RNA in-terference experiments showed that overexpression of 7 genes(CYP392A1,TcGSTd05,CCE06,CYP389A1,TcGSTz01,CCE59,and CYP389C2)is involved in the development of cyflumetofen resistance in Tetranychus cinnabarinus.The recombinant CYP392A1 can effectively metabolize cyflumetofen,while CCE06 can bind and sequester cyflumetofen in vitro.We compared 2 methods for rapid screening of resistance molecular markers,in-cluding short-term induction and 1-time high-dose selection.Two detoxification enzyme genes were upregulated in the field susceptible strain(YN-S)by induction with 20%lethal concentration(LC2o)of cyflumetofen.However,16 detoxification enzyme genes were up-regulated by 1-time selection with LCso of cyflumetofen.Interestingly,the 16 genes were overexpressed in all 3 resistance stages.These results indicated that 1685 genes that were upregulated at the L stage constituted the basis of cyflumetofen resistance,of which 192 genes in which upregulation continued to increase were the main driving force for the de-velopment of resistance.Moreover,the 1-time high-dose selection is an efficient way to rapidly obtain the resistance-related genes that can aid in the development of resistance markers and resistance management in mites.展开更多
As an important asset of local culture,intangible cultural heritage with distinct regional characteristics not only enriches the aesthetic education resources of local colleges and uni-versities but also provides a mu...As an important asset of local culture,intangible cultural heritage with distinct regional characteristics not only enriches the aesthetic education resources of local colleges and uni-versities but also provides a multi-dimensional research direction for the innovative de-velopment of aesthetic education.Taking Xi'an Municipal Intangible Cultural Heritage Gaoling Zhahua as an example,this paper explores how to integrate local intangible cultural heritage into college art education to facilitate its inheritance.It delves into the strate-gies and practical approaches for incorporating local intangible cultural heritage into aes-thetic education in colleges and universities.The innovative practices of the Xi'an Insti-tute of Technology and Business in its University Aesthetic Education course,through the teaching method of"living inheritance,"cultivate students'sense of cultural identity and artistic creativity.Additionally,the paper discusses the application of modern science and technology in the inheritance and promotion of intangible cultural heritage.展开更多
基金This work was supported by the National Nature Science Foundation of China(Grant Nos.42177139 and 41941017)the Natural Science Foundation Project of Jilin Province,China(Grant No.20230101088JC).The authors would like to thank the anonymous reviewers for their comments and suggestions.
文摘The aperture of natural rock fractures significantly affects the deformation and strength properties of rock masses,as well as the hydrodynamic properties of fractured rock masses.The conventional measurement methods are inadequate for collecting data on high-steep rock slopes in complex mountainous regions.This study establishes a high-resolution three-dimensional model of a rock slope using unmanned aerial vehicle(UAV)multi-angle nap-of-the-object photogrammetry to obtain edge feature points of fractures.Fracture opening morphology is characterized using coordinate projection and transformation.Fracture central axis is determined using vertical measuring lines,allowing for the interpretation of aperture of adaptive fracture shape.The feasibility and reliability of the new method are verified at a construction site of a railway in southeast Tibet,China.The study shows that the fracture aperture has a significant interval effect and size effect.The optimal sampling length for fractures is approximately 0.5e1 m,and the optimal aperture interpretation results can be achieved when the measuring line spacing is 1%of the sampling length.Tensile fractures in the study area generally have larger apertures than shear fractures,and their tendency to increase with slope height is also greater than that of shear fractures.The aperture of tensile fractures is generally positively correlated with their trace length,while the correlation between the aperture of shear fractures and their trace length appears to be weak.Fractures of different orientations exhibit certain differences in their distribution of aperture,but generally follow the forms of normal,log-normal,and gamma distributions.This study provides essential data support for rock and slope stability evaluation,which is of significant practical importance.
基金supported by the National Natural Science Foundation of China NSFC-U1809213National Natural Science Foundation of China NSFC-21975222.
文摘Spun-bond non-woven fabrics(NWFs)made of porous C-shaped polypropylene fibers were applied in rapid oil absorption and effective on-line oil spillage monitoring.It is of great interest to further optimize the absorption properties of these materials by tuning their preparation parameters as well as characterize them with theoretical models.In this paper,effects of die shape,diluent composition(mixtures of dibutyl and dioctyl phthalate),and drawing speed on their porous structure and oil-absorbing performance were systematically investigated and characterized based on two novel concepts,i.e.,the equivalent capillary tube pore radius and the kinetic pore tortuosity(barrier to access)derived from the simplest capillary tube liquid-filling model.The use of higher dibutyl phthalate fractions under faster drawing speeds resulted in the formation of larger and more connected inner filament sub-micron pores.Three stages of tube filling relating to inter-filament large pores,medium pores close to bonding points,and inner filament small pores were observed in the spun-bond NWFs.Continuous oil recovery rates of 986 L·m^(-2)·h^(-1) with an oil/water selectivity of 6.4 were achieved in dynamic skimming experiments using simulated spilled oil.
基金This study was supported by the National Natural Science Foundation of China(Nos.21675032 and 81861138040)the Fundamental Research Funds for the Central Universities and DHU Distinguished Young Professor Program.We appreciate the kind help from Dr.Li Wang in Center of Analysis and Measurement,Fudan University for preparation of complicated samples and elemental analysis.
文摘Single atom catalyst is of great importance for the oxygen reduction reaction(ORR).However,facile preparation of single atom catalyst without using well-designed precursors or labor-intensive acid leaching remains an urgent challenge.Herein,a simple pyrolysis of Fe3+-loaded mesoporous phenolic resin(mPF)-melamine precursor is used to prepare the single atom iron-anchored N-doped mesoporous graphitic carbon nanospheres(Fe/N-MGN).Investigation of the synthesis reveals the appropriate Fe-assisted catalysis effect and mPF template effect,which not only spurs the highly graphitic porous framework of Fe/N-MGN with plentiful pyridinic N/graphitic N,but also assures the dispersed single atom Fe anchoring without elaborated procedures.As a result,the as-synthesized Fe/N-MGN demonstrates high catalytic activity,good durability and excellent methanol tolerance for ORR.This work promises a facile method to regulate the graphitic carbon growth and single atom Fe loading for the highly efficient electrocatalysis.
基金the National Natural Science Foundation of China (No. 21675032)the Fundamental Research Funds for the Central Universities and DHU Distinguished Young Professor Program.
文摘Labor-saving preparation of highly active electrocatalysts for alcohols oxidation, especially for the ethylene glycol and glycerol electrooxidation is of great importance for the development of fuel cells. Herein, mesocellular graphene foam (MGF) constructed by ultrathin nanosheets were prepared using lamellar MCM-22 zeolite as template and then ultra-small Pd NPs were facile grew on it via the stabilizer-free synthesis. Detailed characterizations showed that the obtained Pd/MGF had large surface area, hierarchical porous architecture, semi-graphitic framework and dispersed Pd NPs an chori ng. Electrochemical measurements dem on strated that Pd/MGF possessed the higher catalytic activity (1.7-2.9 fold higher) and stability for the different alcohols electrooxidation, especially for the ethylene glycol and glycerol electrooxidation in the alkaline solution, than the commercial Pd/C (10 wt.%) catalyst. Reaction kinetics analysis revealed the expanded diffusion-controlled process of Pd/MGF as compared to Pd/C. These findings promised a potential electrocatalyst for direct alcohol fuel cells (DAFC), especially for the direct ethylene glycol or glycerol fuel cells with high energy density.
基金the Social Development Item of Jiangsu Province of China(No.BS2005050)the Key Project of Chinese Ministry of Education(No.108150)the open study of Engineering Research Center of Water Treatment and Water Environment Remediation of Chinese Ministry of Education(WTWER0721)。
文摘Batch experiments were conducted to study the short-term biological effects of rare earth ions(La^(3+),Ce^(3+))and their mixture on the nitrogen removal in a sequencing batch reactor(SBR).The data showed that higher NH4+–N removal rate,total inorganic nitrogen removal efficiency,and denitrification efficiency were achieved at lower concentrations of rare earth elements(REEs)(<1 mg/L).In the first hour of the aeration stage of SBR,the presence of REEs increased the total inorganic nitrogen removal efficiency and NH4+–N removal effi-ciency by 15.7%and 10%–15%,respectively.When the concentrations of REEs were higher than 1 mg/L,the total inorganic nitrogen removal efficiency decreased,and nitrate was found to accumulate in the effluent.When the concentrations of REEs was up to 50.0 mg/L,the total inorganic nitrogen removal efficiency was less than 30%of the control efficiency with a high level of nitrate.Lower concentrations of REEs were found to accelerate the nitrogen conversion and removal in SBR.
基金The National Natural Science Foundation of China(no.31972297no.32202337)Chongqing Postdoctoral Science Foundation(cstc202ljcyj-bshX0050).
文摘Changes in gene expression are associated with the evolution of pesticide resis-tance in arthropods.In this study,transcriptome sequencing was performed in 3 different resistance levels(low,L;medium,M;and high,H)of cyflumetofen-resistant strain(YN-CyR).A total of 1685 genes,including 97 detoxification enzyme genes,were upregulated in all 3 stages,of which 192 genes,including 11 detoxification enzyme genes,showed a continuous increase in expression level with resistance development(L to H).RNA in-terference experiments showed that overexpression of 7 genes(CYP392A1,TcGSTd05,CCE06,CYP389A1,TcGSTz01,CCE59,and CYP389C2)is involved in the development of cyflumetofen resistance in Tetranychus cinnabarinus.The recombinant CYP392A1 can effectively metabolize cyflumetofen,while CCE06 can bind and sequester cyflumetofen in vitro.We compared 2 methods for rapid screening of resistance molecular markers,in-cluding short-term induction and 1-time high-dose selection.Two detoxification enzyme genes were upregulated in the field susceptible strain(YN-S)by induction with 20%lethal concentration(LC2o)of cyflumetofen.However,16 detoxification enzyme genes were up-regulated by 1-time selection with LCso of cyflumetofen.Interestingly,the 16 genes were overexpressed in all 3 resistance stages.These results indicated that 1685 genes that were upregulated at the L stage constituted the basis of cyflumetofen resistance,of which 192 genes in which upregulation continued to increase were the main driving force for the de-velopment of resistance.Moreover,the 1-time high-dose selection is an efficient way to rapidly obtain the resistance-related genes that can aid in the development of resistance markers and resistance management in mites.
基金The phased results of the 2024 Shaanxi Provincial Philosophy and Social Science Research Special Youth Project(2024QN345)"Research on the Art Excavation and Living Inheritance of Gaoling Zhahua from the Perspective of Intangible Cultural Heritage"The phased results of the"Folk Culture(Intangible Cultural Heritage)Entering the Campus"scientifc research project of the Chinese Folk Literary and Artists Association and the Chinese Association for Democracy and People's Livelihood(2023333)"Live Inheritance-Research on Intangible Cultural Heritage Skills Training for Teachers and Students in Colleges and Universities in"Gaoling Zhahua".
文摘As an important asset of local culture,intangible cultural heritage with distinct regional characteristics not only enriches the aesthetic education resources of local colleges and uni-versities but also provides a multi-dimensional research direction for the innovative de-velopment of aesthetic education.Taking Xi'an Municipal Intangible Cultural Heritage Gaoling Zhahua as an example,this paper explores how to integrate local intangible cultural heritage into college art education to facilitate its inheritance.It delves into the strate-gies and practical approaches for incorporating local intangible cultural heritage into aes-thetic education in colleges and universities.The innovative practices of the Xi'an Insti-tute of Technology and Business in its University Aesthetic Education course,through the teaching method of"living inheritance,"cultivate students'sense of cultural identity and artistic creativity.Additionally,the paper discusses the application of modern science and technology in the inheritance and promotion of intangible cultural heritage.
