Natural rubber is an indispensable material of strategic importance that has critical applications in industry and the military.However,the development of the natural rubber industry is impeded by the red root rot dis...Natural rubber is an indispensable material of strategic importance that has critical applications in industry and the military.However,the development of the natural rubber industry is impeded by the red root rot disease of rubber trees caused by Ganoderma pseudoferreum,which is one of the most devastating diseases in the rubber tree growing regions in China.To combat this disease,we screened the antifungal activity of 223 candidate bacterial strains against G.pseudoferreum,and found that Bacillus velezensis strain SF305 exhibited significant antifungal activity against G.pseudoferreum.Bacillus velezensis SF305 had a nearly 70%efficacy against the red root rot disease of rubber trees with the therapeutic treatment(Tre),while it exhibited over 90%protection effectiveness with the preventive treatment(Pre).The underlying biocontrol mechanism revealed that B.velezensis SF305 could reduce the disease severity of red root rot by degrading the mycelia of G.pseudoferreum.An antiSMASH analysis revealed that B.velezensis SF305 contains 15 gene clusters related to secondary metabolite synthesis,13 of which are conserved in species of B.velezensis,but surprisingly,B.velezensis SF305 possesses 2 unique secondary metabolite gene clusters.One is predicted to synthesize locillomycin,and the other is a novel nonribosomal peptides synthetase(NRPS)gene cluster.Genomic analysis showed that B.velezensis SF305 harbors genes involved in motility,chemotaxis,biofilm formation,stress resistance,volatile organic compounds(VOCs)and synthesis of the auxin indole-3-acetic acid(IAA),suggesting its plant growth-promoting rhizobacteria(PGPR)properties.Bacillus velezensis SF305 can promote plant growth and efficiently antagonize some important phytopathogenic fungi and bacteria.This study indicates that B.velezensis SF305 is a versatile plant probiotic bacterium.To the best of our knowledge,this is the first time a B.velezensis strain has been reported as a promising biocontrol agent against the red root rot disease of rubber trees.展开更多
The key problem to be solved urgently is how to avoid the occurrence of support break-off and water inrush in the stoping of sandstone straight roof under the action of load transfer in unconsolidated aquifer.For this...The key problem to be solved urgently is how to avoid the occurrence of support break-off and water inrush in the stoping of sandstone straight roof under the action of load transfer in unconsolidated aquifer.For this reason,taking the thin bedrock 1602(3)working face of Huainan(the middle part of Anhui Province)Panyi Coal Mine as the engineering background,this study establishes the stope mining model by using the discrete element UDEC software and the mathematics mechanical model of the support load,and analyzes the reason of support crushing and decides to re-mining the working face by using the compulsive roof caving method.It is concluded that when the working face of sandstone straight roof is broken,the"voussoir beam"structure cannot be formed and acts on the support in the form of cantilever beam,but only when it falls to the high key stratum can the"voussoir beam"structure be formed and at this point,at this time,the bracket bears the weight of the rock layer in the range from the fractured sandstone layer to the lower critical layer.The working resistance of the support increases with the increase of the thickness and the breaking length of straight sandstone roof.When the breaking length of the roof reaches a certain extreme value,the support crushing accidents will occur.Managing roof with compulsive roof caving method can reduce the intensity of rock pressure in the stope,and the working face can be safely stoped,which provides a certain reference for similar conditions.展开更多
Soil is the most biologically abundant ecosystem on the earth.Soil biodiversity has significant impact on maintaining soil ecological balance and agricultural production,especially on healthy growth and disease contro...Soil is the most biologically abundant ecosystem on the earth.Soil biodiversity has significant impact on maintaining soil ecological balance and agricultural production,especially on healthy growth and disease control of plants.Therefore,it is of great significance to study soil biodiversity.This paper reviewed the role of soil biodiversity in plant growth.First of all,the history of soil biodiversity was introduced.Secondly,the composition of soil biodiversity was introduced,and the role of soil biodiversity in regulating the quantity and species of soil organisms,maintaining the balance and stability of soil system,participating in nutrient circulation and energy flow,and promoting plant health were discussed based on the interactions among microbial diversity,fauna diversity and plant diversity.Finally,combined with the background of advocating the protection of soil biodiversity in the great time,the potential factors threatening soil biodiversity were analyzed.展开更多
[Objectives]The paper was to understand the species and pathogenicity of the pathogen causing potato early blight in winter.[Methods]The occurrence of potato early blight was investigated in 5 winter potato growing ar...[Objectives]The paper was to understand the species and pathogenicity of the pathogen causing potato early blight in winter.[Methods]The occurrence of potato early blight was investigated in 5 winter potato growing areas in Yunnan Province.The disease samples were collected from two locations(Zhutang Village and Zhanai Village,Pu'er City)where the occurrence of early blight was severe.The pathogen was isolated and purified in laboratory and identified by morphological characteristics and phylogenetic analysis of ITS gene sequence.And it was further verified via re-inoculation by Koch's rules.The growth characteristics and pathogenicity of isolates in different seasons were analyzed with 4 strains of Alternaria isolated in spring(EYZ,EYAX,TA1 and TAC)as controls.[Results]Early blight occurred in varying degrees in the 5 winter potato growing areas,and the incidence of early blight was up to 100%in some plots in Lancang County,Pu'er City.A total of 35 strains of Alternaria were isolated from plots with high incidence,which were divided into two types according to colony morphology.The first type was round colonies with smooth edges and gray white fronts,and the second type was round colonies with rough edges and gray black fronts.Three strains LC1,LC2,LC3 of the first type and two strains ZT3 and ZT8 of the second type were selected and identified as Alternaria alternata through morphological and molecular identification.Re-inoculation test further confirmed that the pathogen was A.alternata.Meantime,it was found that the growth rate of colonies isolated in winter was relatively slow,and there was no significant difference between the pathogenicity of LC1 and TA1,but the pathogenicity of strains isolated in winter was generally higher than that isolated in spring.[Conclusions]It is confirmed that the pathogen causing potato early blight in winter is A.alternata in Yunnan Province.The results will lay a foundation for the research of pathogenesis,occurrence regularity and disease control of A.alternata in winter potato.展开更多
The relentless drive toward miniaturization in the semiconductor industry demands photoresists capable of patterning sub-20 nm features for next-generation extreme ultraviolet(EUV)lithography.Metal-oxo clusters,with s...The relentless drive toward miniaturization in the semiconductor industry demands photoresists capable of patterning sub-20 nm features for next-generation extreme ultraviolet(EUV)lithography.Metal-oxo clusters,with sub-5 nm molecular dimensions,structural tunability,and high EUV absorption via metal centers,have emerged as promising EUV photoresist candidates.Advancing next-generation photoresist materials necessitates resolving the inherent trade-offs between sensitivity,resolution,and line-edge roughness.In this work,we report a series of halogenated metal-organic clusters based EUVL photoresists,aiming to modulate the sensitivity,resolution,and line-edge roughness.Here,we report the synthesis of halogenated metal-organic clusters as EUVL photoresists,designed to modulate the resolution-line edge roughness-sensitivity trade-off.Sub-20 nm critical dimensions and line edge roughness below 2 nm were achieved with the clusters by EUVL.The results demonstrated that halogen elements influenced the sensitivity of the clusters.To unravel the EUV-driven reaction pathways,we analyzed the chemical transformations in these clusters after exposure using X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy.These findings pave the way for the rational design of high-performance EUV photoresists.展开更多
Due to their various interesting properties(e.g.,porosity,chirality,magnetism and luminescence),metal-organic frameworks(MOFs)show great potential in a large number of applications ranging from life sciences to indust...Due to their various interesting properties(e.g.,porosity,chirality,magnetism and luminescence),metal-organic frameworks(MOFs)show great potential in a large number of applications ranging from life sciences to industry.One way to process and formulate them into application-specific configurations is to fabricate composite materials where MOFs are mounted on flat substrates or other shaped bodies.Among the library of MOF film preparation techniques,the liquid phase stepwise growth approach has shown its feasibility in the fabrication of homogeneous and highly crystalline surface-mounted MOFs.This review will focus on the fundamental properties(e.g.,growth mechanism,sorption,electrical and mechanical properties)of stepwise grown MOF films toward the development of their applications in separation,chemical sensing and catalysis.展开更多
Shaping crystalline porous materials such as metal organic frameworks （MOFs） and zeolites into two-dimensional （2D） nanosheet forms is highly desirable for developing high-performance molecular sieving membranes. ...Shaping crystalline porous materials such as metal organic frameworks （MOFs） and zeolites into two-dimensional （2D） nanosheet forms is highly desirable for developing high-performance molecular sieving membranes. However, conventional exfoliation-deposition is complex and challenging for the large-scale fabrication of nanosheet MOF tubular membranes. Here, for the first time, we report a direct growth technique by ZnO self-conversion and ammonia assistance to fabricate zeolitic imidazolate framework （ZIF） membranes consisting of 2D nanosheets on porous hollow fiber substrates; the membranes are suitable for large-scale industrial gas separation processes. The proposed fabrication process for ZIF nanosheet membranes is based on the localized self-conversion of a pre-deposited thin layer of ZnO in a ligand solution containing ammonium hydroxide as a modulator. The resulting ZIF 2D nanosheet tubular membrane is highly oriented and only 50 nm in thickness. It exhibits excellent molecular sieving performance, with high H2 permeance and selectivity for H2/CO2 separation. This technique shows great promise in MOF nanosheet membrane fabrication for large-scale molecular sieving applications.展开更多
基金financially supported by the National Key Research and Development Program of China(2023YFD1200204)the Special Fund for Hainan Excellent Team“Rubber Genetics and Breeding”,China(20210203)。
文摘Natural rubber is an indispensable material of strategic importance that has critical applications in industry and the military.However,the development of the natural rubber industry is impeded by the red root rot disease of rubber trees caused by Ganoderma pseudoferreum,which is one of the most devastating diseases in the rubber tree growing regions in China.To combat this disease,we screened the antifungal activity of 223 candidate bacterial strains against G.pseudoferreum,and found that Bacillus velezensis strain SF305 exhibited significant antifungal activity against G.pseudoferreum.Bacillus velezensis SF305 had a nearly 70%efficacy against the red root rot disease of rubber trees with the therapeutic treatment(Tre),while it exhibited over 90%protection effectiveness with the preventive treatment(Pre).The underlying biocontrol mechanism revealed that B.velezensis SF305 could reduce the disease severity of red root rot by degrading the mycelia of G.pseudoferreum.An antiSMASH analysis revealed that B.velezensis SF305 contains 15 gene clusters related to secondary metabolite synthesis,13 of which are conserved in species of B.velezensis,but surprisingly,B.velezensis SF305 possesses 2 unique secondary metabolite gene clusters.One is predicted to synthesize locillomycin,and the other is a novel nonribosomal peptides synthetase(NRPS)gene cluster.Genomic analysis showed that B.velezensis SF305 harbors genes involved in motility,chemotaxis,biofilm formation,stress resistance,volatile organic compounds(VOCs)and synthesis of the auxin indole-3-acetic acid(IAA),suggesting its plant growth-promoting rhizobacteria(PGPR)properties.Bacillus velezensis SF305 can promote plant growth and efficiently antagonize some important phytopathogenic fungi and bacteria.This study indicates that B.velezensis SF305 is a versatile plant probiotic bacterium.To the best of our knowledge,this is the first time a B.velezensis strain has been reported as a promising biocontrol agent against the red root rot disease of rubber trees.
基金The authors are grateful to the National Natural Science Foundation of China(Nos.51574007 and 51604007).
文摘The key problem to be solved urgently is how to avoid the occurrence of support break-off and water inrush in the stoping of sandstone straight roof under the action of load transfer in unconsolidated aquifer.For this reason,taking the thin bedrock 1602(3)working face of Huainan(the middle part of Anhui Province)Panyi Coal Mine as the engineering background,this study establishes the stope mining model by using the discrete element UDEC software and the mathematics mechanical model of the support load,and analyzes the reason of support crushing and decides to re-mining the working face by using the compulsive roof caving method.It is concluded that when the working face of sandstone straight roof is broken,the"voussoir beam"structure cannot be formed and acts on the support in the form of cantilever beam,but only when it falls to the high key stratum can the"voussoir beam"structure be formed and at this point,at this time,the bracket bears the weight of the rock layer in the range from the fractured sandstone layer to the lower critical layer.The working resistance of the support increases with the increase of the thickness and the breaking length of straight sandstone roof.When the breaking length of the roof reaches a certain extreme value,the support crushing accidents will occur.Managing roof with compulsive roof caving method can reduce the intensity of rock pressure in the stope,and the working face can be safely stoped,which provides a certain reference for similar conditions.
基金Supported by High-level Talents Program of Basic and Applied Basic Research Program of Hainan Province(2019RC332)。
文摘Soil is the most biologically abundant ecosystem on the earth.Soil biodiversity has significant impact on maintaining soil ecological balance and agricultural production,especially on healthy growth and disease control of plants.Therefore,it is of great significance to study soil biodiversity.This paper reviewed the role of soil biodiversity in plant growth.First of all,the history of soil biodiversity was introduced.Secondly,the composition of soil biodiversity was introduced,and the role of soil biodiversity in regulating the quantity and species of soil organisms,maintaining the balance and stability of soil system,participating in nutrient circulation and energy flow,and promoting plant health were discussed based on the interactions among microbial diversity,fauna diversity and plant diversity.Finally,combined with the background of advocating the protection of soil biodiversity in the great time,the potential factors threatening soil biodiversity were analyzed.
基金Major Science and Technology Special Plan of Yunnan Department of Science and Technology(202102AE090018)Key Research and Development Program of Hainan Province(ZDYF2021XDNY291).
文摘[Objectives]The paper was to understand the species and pathogenicity of the pathogen causing potato early blight in winter.[Methods]The occurrence of potato early blight was investigated in 5 winter potato growing areas in Yunnan Province.The disease samples were collected from two locations(Zhutang Village and Zhanai Village,Pu'er City)where the occurrence of early blight was severe.The pathogen was isolated and purified in laboratory and identified by morphological characteristics and phylogenetic analysis of ITS gene sequence.And it was further verified via re-inoculation by Koch's rules.The growth characteristics and pathogenicity of isolates in different seasons were analyzed with 4 strains of Alternaria isolated in spring(EYZ,EYAX,TA1 and TAC)as controls.[Results]Early blight occurred in varying degrees in the 5 winter potato growing areas,and the incidence of early blight was up to 100%in some plots in Lancang County,Pu'er City.A total of 35 strains of Alternaria were isolated from plots with high incidence,which were divided into two types according to colony morphology.The first type was round colonies with smooth edges and gray white fronts,and the second type was round colonies with rough edges and gray black fronts.Three strains LC1,LC2,LC3 of the first type and two strains ZT3 and ZT8 of the second type were selected and identified as Alternaria alternata through morphological and molecular identification.Re-inoculation test further confirmed that the pathogen was A.alternata.Meantime,it was found that the growth rate of colonies isolated in winter was relatively slow,and there was no significant difference between the pathogenicity of LC1 and TA1,but the pathogenicity of strains isolated in winter was generally higher than that isolated in spring.[Conclusions]It is confirmed that the pathogen causing potato early blight in winter is A.alternata in Yunnan Province.The results will lay a foundation for the research of pathogenesis,occurrence regularity and disease control of A.alternata in winter potato.
基金supported by the National Science and Technology Major Project from the Ministry of Science and Technology of China(No.2018AAA0103100)the National Key Research and Development Program of China(No.2021YFB3200800)the National Natural Science Foundation of China(Nos.22201289,62305365)for financial support。
文摘The relentless drive toward miniaturization in the semiconductor industry demands photoresists capable of patterning sub-20 nm features for next-generation extreme ultraviolet(EUV)lithography.Metal-oxo clusters,with sub-5 nm molecular dimensions,structural tunability,and high EUV absorption via metal centers,have emerged as promising EUV photoresist candidates.Advancing next-generation photoresist materials necessitates resolving the inherent trade-offs between sensitivity,resolution,and line-edge roughness.In this work,we report a series of halogenated metal-organic clusters based EUVL photoresists,aiming to modulate the sensitivity,resolution,and line-edge roughness.Here,we report the synthesis of halogenated metal-organic clusters as EUVL photoresists,designed to modulate the resolution-line edge roughness-sensitivity trade-off.Sub-20 nm critical dimensions and line edge roughness below 2 nm were achieved with the clusters by EUVL.The results demonstrated that halogen elements influenced the sensitivity of the clusters.To unravel the EUV-driven reaction pathways,we analyzed the chemical transformations in these clusters after exposure using X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy.These findings pave the way for the rational design of high-performance EUV photoresists.
基金funded within the Priority Program 1362“Metal-Organic Frameworks”of the German Research Foundation(DFG)a PhD fellowship from the China Scholarship Council(CSC).
文摘Due to their various interesting properties(e.g.,porosity,chirality,magnetism and luminescence),metal-organic frameworks(MOFs)show great potential in a large number of applications ranging from life sciences to industry.One way to process and formulate them into application-specific configurations is to fabricate composite materials where MOFs are mounted on flat substrates or other shaped bodies.Among the library of MOF film preparation techniques,the liquid phase stepwise growth approach has shown its feasibility in the fabrication of homogeneous and highly crystalline surface-mounted MOFs.This review will focus on the fundamental properties(e.g.,growth mechanism,sorption,electrical and mechanical properties)of stepwise grown MOF films toward the development of their applications in separation,chemical sensing and catalysis.
基金This work was supported by the National Natural Science Foundation of China （Nos. 21476039 and 21076030）. M. T. thanks the Marie S~odowska-Curie Individual Fellowship for a postdoctoral grant. A. J. H. and O. K. F. gratefully acknowledge funding from the U.S. Dept. of F.nerg~ Office of Science, Basic Energy Sciences Program （No. DE-FG02-08ER15967）. The authors also thank Professor Huanting Wang from Monash University for further revising the manuscript.
文摘Shaping crystalline porous materials such as metal organic frameworks （MOFs） and zeolites into two-dimensional （2D） nanosheet forms is highly desirable for developing high-performance molecular sieving membranes. However, conventional exfoliation-deposition is complex and challenging for the large-scale fabrication of nanosheet MOF tubular membranes. Here, for the first time, we report a direct growth technique by ZnO self-conversion and ammonia assistance to fabricate zeolitic imidazolate framework （ZIF） membranes consisting of 2D nanosheets on porous hollow fiber substrates; the membranes are suitable for large-scale industrial gas separation processes. The proposed fabrication process for ZIF nanosheet membranes is based on the localized self-conversion of a pre-deposited thin layer of ZnO in a ligand solution containing ammonium hydroxide as a modulator. The resulting ZIF 2D nanosheet tubular membrane is highly oriented and only 50 nm in thickness. It exhibits excellent molecular sieving performance, with high H2 permeance and selectivity for H2/CO2 separation. This technique shows great promise in MOF nanosheet membrane fabrication for large-scale molecular sieving applications.
