抗生素能够影响土壤微生物群落结构和功能多样性从而影响微生物介导的氮循环过程,改变土壤环境中各种氮素形态和脲酶活性,进而影响土壤氮循环。为了量化分析土壤中抗生素对土壤氮循环的影响,本研究从中国知网和Web of Science数据库收集...抗生素能够影响土壤微生物群落结构和功能多样性从而影响微生物介导的氮循环过程,改变土壤环境中各种氮素形态和脲酶活性,进而影响土壤氮循环。为了量化分析土壤中抗生素对土壤氮循环的影响,本研究从中国知网和Web of Science数据库收集了2002年1月-2024年3月共62篇相关文献,从中提取相关数据用R语言进行Meta分析,综合不同时空甚至结论相悖的研究结果,得出更一般、普遍的研究结论,揭示抗生素对土壤氮素循环的影响机理。结果表明:四环素类(TCs)、磺胺类(SAs)和喹诺酮类(QNs)三类抗生素会抑制土壤脲酶活性、amoA-AOA和amoA-AOB,促进土壤NH_(3)挥发,降低氨氧化速率,减缓土壤氮素循环。TCs降低了土壤NH_(4)^(+)-N、NO_(2)^(-)-N和NO_(3)^(-)-N含量,而SAs和QNs提高土壤NH_(4)^(+)-N含量,降低了土壤NO_(2)^(-)-N和NO_(3)^(-)-N含量。基于以上研究,三类抗生素总体抑制氨化作用、硝化作用和反硝化作用中的各类指标;但SAs增加NH_(4)^(+)-N、nirK、nirS和nosZ,促进NH_(3)排放;QNs增加NH_(4)^(+)-N和促进N_(2)O排放,这与抗生素的类型及抗生素类型影响的相关微生物有关。展开更多
Biotic stresses negatively affect canola growth and production. Flea beetle damage and Sclerotinia sclerotiorum (S. sclerotiorum) infection are two of the worst biotic stresses for canola. Auxin Repressed Proteins (AR...Biotic stresses negatively affect canola growth and production. Flea beetle damage and Sclerotinia sclerotiorum (S. sclerotiorum) infection are two of the worst biotic stresses for canola. Auxin Repressed Proteins (ARPs) responsive to several abiotic stresses have been reported. However, information about ARPs induced by Flea beetle damage and S. sclerotiorum infection, their roles in biotic stress tolerance are still lacking in canola. ESTs for an Auxin Repressed Protein 1 (BnARP1) were highly represented (expressed) in a Brassica napus subtractive library developed after leaf damage by the crucifer flea beetle (Phyllotreta cruciferae). Expression of this gene was under different developmental control in B. napus, and it was co-induced in B. napus by flea beetle feeding, S. sclerotiorum infection, drought and cold. A total of 25 BnARP genes were represented in different B. napus stress and development EST libraries and indicated larger, diversified families than known earlier. Dwarf phenotypes, primary root growth inhibition, lateral root enhancement, reduced sensitivity to 2, 4-D, and reduced PIN1 and LOX expression in transgenic Arabidopsis expression lines suggest that BnARP1 is an auxin repressor that prevents auxin transport and supports an interaction between the auxin and jasmonate signalling pathways. And the increased survival after S. sclerotiorum infection in transgenic over-expression Arabidopsis suggests that BnARP1 could play a role in S. sclerotiorum tolerance through connecting auxin and jasmonate signalling pathways.展开更多
The study explores the processing and characterization of dense tungsten carbide(WC)–10 wt.%nickel(Ni)structures(WC-10Ni)built using laser powder bed fusion(LPBF).LPBF experimental trials were conducted at different ...The study explores the processing and characterization of dense tungsten carbide(WC)–10 wt.%nickel(Ni)structures(WC-10Ni)built using laser powder bed fusion(LPBF).LPBF experimental trials were conducted at different combinations of process parameters based on central composite design to develop process maps.Three samples built at different laser energy densities(LED of 460,381.7 and 300 J·m^(-3))with a 10 wt.%high relative density(>83.8%)were subjected to microstructural analysis,phase analysis,microhardness assessment,and abrasive wear testing.The characterizations focused on understanding the microstructure and mechanical behavior of LPBF-built WC-10Ni and developing a correlation between LED and material behavior.Higher LED resulted in keyhole porosity,while lower LED led to lack-of-fusion pores.The carbide particle size increased with LED,attributed to thermal cycling and coalescence during solidification.Higher LED also induced phase transformations,such as,the decomposition of WC into W_(2)C and the oxidation of Ni.Microhardness testing showed that the WC phase reached 1650 HV1,while the Ni matrix reached 1011 HV1.The abrasive wear testing demonstrated mass loss of<1%.Investigation of the wear scar resulted in the conclusion that the uniform distribution of WC particles in the Ni matrix contributed to this performance.The above studies indicate a positive correlation among relative density,hardness,and wear resistance.The study paves the way to understand the processing and material characteristics of LPBF-built WC-10Ni.展开更多
To avoid resource wastage and secondary environmental pollution,recycling and reusing waste wood powder is still a great challenge.Moreover,the poor viscosity and irregular pore size of wood powder limit its practical...To avoid resource wastage and secondary environmental pollution,recycling and reusing waste wood powder is still a great challenge.Moreover,the poor viscosity and irregular pore size of wood powder limit its practical application.This study,employed a green and convenient wood powder reconstitution strategy to achieve highly adhesive bonding and pore size control between wood powder particles,thus preparing a high-strength and super hydrophilic wood powder membrane.The wood powder fibers were partially dissolved and regenerated to create a reconstituted wood powder hydrogel membrane,using waste wood powder as the raw material.The wood powder reconstitution strategy offers advantages such as environmental friendliness,simplicity,cost-effectiveness,and strong universality.Furthermore,the materials exhibit excellent self-cleaning properties and superhydrophilicity.Driven by gravity,the membrane can purify oily wastewater and dyes.Additionally,the reconstitution strategy offers a new pathway for recycling wood powder.展开更多
Nanocellulose is a sustainable and eco-friendly nanomaterial derived from renewable biomass. In this study, we utilized the structural advantages of two types of nanocellulose and fabricated freestanding carbonized hy...Nanocellulose is a sustainable and eco-friendly nanomaterial derived from renewable biomass. In this study, we utilized the structural advantages of two types of nanocellulose and fabricated freestanding carbonized hybrid nanocellulose films as electrode materials for supercapacitors. The long cellulose nanofibrils （CNFs） formed a macroporous framework, and the short cellulose nanocrystals were assembled around the CNF framework and generated micro/mesopores. This two-level hierarchical porous structure was successfully preserved during carbonization because of a thin atomic layer deposited （ALD） A1203 conformal coating, which effectively prevented the aggregation of nanocellulose. These carbonized, partially graphitized nanocellulose fibers were interconnected, forming an integrated and highly conductive network with a large specific surface area of 1,244 m2·g-1. The two-level hierarchical porous structure facilitated fast ion transport in the film. When tested as an electrode material with a high mass loading of 4 mg·cm-2 for supercapacitors, the hierarchical porous carbon film derived from hybrid nanocellulose exhibited a specific capacitance of 170 F·g-1 and extraordinary performance at high current densities. Even at a very high current of 50 A-g-l, it retained 65% of its original specific capacitance, which makes it a promising electrode material for high-power applications.展开更多
文摘抗生素能够影响土壤微生物群落结构和功能多样性从而影响微生物介导的氮循环过程,改变土壤环境中各种氮素形态和脲酶活性,进而影响土壤氮循环。为了量化分析土壤中抗生素对土壤氮循环的影响,本研究从中国知网和Web of Science数据库收集了2002年1月-2024年3月共62篇相关文献,从中提取相关数据用R语言进行Meta分析,综合不同时空甚至结论相悖的研究结果,得出更一般、普遍的研究结论,揭示抗生素对土壤氮素循环的影响机理。结果表明:四环素类(TCs)、磺胺类(SAs)和喹诺酮类(QNs)三类抗生素会抑制土壤脲酶活性、amoA-AOA和amoA-AOB,促进土壤NH_(3)挥发,降低氨氧化速率,减缓土壤氮素循环。TCs降低了土壤NH_(4)^(+)-N、NO_(2)^(-)-N和NO_(3)^(-)-N含量,而SAs和QNs提高土壤NH_(4)^(+)-N含量,降低了土壤NO_(2)^(-)-N和NO_(3)^(-)-N含量。基于以上研究,三类抗生素总体抑制氨化作用、硝化作用和反硝化作用中的各类指标;但SAs增加NH_(4)^(+)-N、nirK、nirS和nosZ,促进NH_(3)排放;QNs增加NH_(4)^(+)-N和促进N_(2)O排放,这与抗生素的类型及抗生素类型影响的相关微生物有关。
文摘Biotic stresses negatively affect canola growth and production. Flea beetle damage and Sclerotinia sclerotiorum (S. sclerotiorum) infection are two of the worst biotic stresses for canola. Auxin Repressed Proteins (ARPs) responsive to several abiotic stresses have been reported. However, information about ARPs induced by Flea beetle damage and S. sclerotiorum infection, their roles in biotic stress tolerance are still lacking in canola. ESTs for an Auxin Repressed Protein 1 (BnARP1) were highly represented (expressed) in a Brassica napus subtractive library developed after leaf damage by the crucifer flea beetle (Phyllotreta cruciferae). Expression of this gene was under different developmental control in B. napus, and it was co-induced in B. napus by flea beetle feeding, S. sclerotiorum infection, drought and cold. A total of 25 BnARP genes were represented in different B. napus stress and development EST libraries and indicated larger, diversified families than known earlier. Dwarf phenotypes, primary root growth inhibition, lateral root enhancement, reduced sensitivity to 2, 4-D, and reduced PIN1 and LOX expression in transgenic Arabidopsis expression lines suggest that BnARP1 is an auxin repressor that prevents auxin transport and supports an interaction between the auxin and jasmonate signalling pathways. And the increased survival after S. sclerotiorum infection in transgenic over-expression Arabidopsis suggests that BnARP1 could play a role in S. sclerotiorum tolerance through connecting auxin and jasmonate signalling pathways.
基金funding from NSERC(RGPIN-2023-04460)CFI(No.36664)。
文摘The study explores the processing and characterization of dense tungsten carbide(WC)–10 wt.%nickel(Ni)structures(WC-10Ni)built using laser powder bed fusion(LPBF).LPBF experimental trials were conducted at different combinations of process parameters based on central composite design to develop process maps.Three samples built at different laser energy densities(LED of 460,381.7 and 300 J·m^(-3))with a 10 wt.%high relative density(>83.8%)were subjected to microstructural analysis,phase analysis,microhardness assessment,and abrasive wear testing.The characterizations focused on understanding the microstructure and mechanical behavior of LPBF-built WC-10Ni and developing a correlation between LED and material behavior.Higher LED resulted in keyhole porosity,while lower LED led to lack-of-fusion pores.The carbide particle size increased with LED,attributed to thermal cycling and coalescence during solidification.Higher LED also induced phase transformations,such as,the decomposition of WC into W_(2)C and the oxidation of Ni.Microhardness testing showed that the WC phase reached 1650 HV1,while the Ni matrix reached 1011 HV1.The abrasive wear testing demonstrated mass loss of<1%.Investigation of the wear scar resulted in the conclusion that the uniform distribution of WC particles in the Ni matrix contributed to this performance.The above studies indicate a positive correlation among relative density,hardness,and wear resistance.The study paves the way to understand the processing and material characteristics of LPBF-built WC-10Ni.
基金This work was supported by the Zhejiang Provincial Natural Science Foundation of China(No.LY23D060004)the Science and Technology Planning Project of Zhoushan of China(No.2022C41005)the National Natural Science Foundation of China(No.51606168).
文摘To avoid resource wastage and secondary environmental pollution,recycling and reusing waste wood powder is still a great challenge.Moreover,the poor viscosity and irregular pore size of wood powder limit its practical application.This study,employed a green and convenient wood powder reconstitution strategy to achieve highly adhesive bonding and pore size control between wood powder particles,thus preparing a high-strength and super hydrophilic wood powder membrane.The wood powder fibers were partially dissolved and regenerated to create a reconstituted wood powder hydrogel membrane,using waste wood powder as the raw material.The wood powder reconstitution strategy offers advantages such as environmental friendliness,simplicity,cost-effectiveness,and strong universality.Furthermore,the materials exhibit excellent self-cleaning properties and superhydrophilicity.Driven by gravity,the membrane can purify oily wastewater and dyes.Additionally,the reconstitution strategy offers a new pathway for recycling wood powder.
文摘Nanocellulose is a sustainable and eco-friendly nanomaterial derived from renewable biomass. In this study, we utilized the structural advantages of two types of nanocellulose and fabricated freestanding carbonized hybrid nanocellulose films as electrode materials for supercapacitors. The long cellulose nanofibrils （CNFs） formed a macroporous framework, and the short cellulose nanocrystals were assembled around the CNF framework and generated micro/mesopores. This two-level hierarchical porous structure was successfully preserved during carbonization because of a thin atomic layer deposited （ALD） A1203 conformal coating, which effectively prevented the aggregation of nanocellulose. These carbonized, partially graphitized nanocellulose fibers were interconnected, forming an integrated and highly conductive network with a large specific surface area of 1,244 m2·g-1. The two-level hierarchical porous structure facilitated fast ion transport in the film. When tested as an electrode material with a high mass loading of 4 mg·cm-2 for supercapacitors, the hierarchical porous carbon film derived from hybrid nanocellulose exhibited a specific capacitance of 170 F·g-1 and extraordinary performance at high current densities. Even at a very high current of 50 A-g-l, it retained 65% of its original specific capacitance, which makes it a promising electrode material for high-power applications.
