Lightweight structural materials with high strength and toughness are highly desirable for many advanced applications.Wood,as a sustainable structural material,is widely used in engineer-ing due to its abundance and e...Lightweight structural materials with high strength and toughness are highly desirable for many advanced applications.Wood,as a sustainable structural material,is widely used in engineer-ing due to its abundance and excellent mechanical properties.In this paper,we report a self-densification strategy to develop super-strong wood by reassembling highly aligned wood fibers as functional units and self-densified without the need for hot pressing.The resulting self-densified wood exhibits ultra-high tensile strength(496.1 MPa),flexural strength(392.7 MPa)and impact toughness(75.2 kJ/m^(2)),surpassing those of compressed densified wood and traditional metal materials like aluminum alloys.Notably,the self-densified wood exhibits uniform shrinkage in the cross-section while maintaining its longitudinal dimension.This characteristic leads to an order-of-magnitude enhancement in the overall mechanical performance of the wood,presenting a significant advantage over compressed densified wood.Such super-strong yet lightweight wood has great potential for application as a sustainable engineering material,replacing traditional structural materials such as metals and alloys.展开更多
A cerium film was prepared on the surface of rebar by chemical conversion method to enhance its corrosion resistance.The film in the simulated concrete pore solution was measured by electrochemical method,transmission...A cerium film was prepared on the surface of rebar by chemical conversion method to enhance its corrosion resistance.The film in the simulated concrete pore solution was measured by electrochemical method,transmission electron microscope(TEM)and X-ray photoelectron spectroscopy(XPS).The effect of temperature on film formation was studied,and the optimum temperature was determined at 35℃.The film produced by too high formation temperature has more defects,resulting in the lower corrosion resistance.The Ce film resistance increased with time evolution until 800 h,then decreased and stabilized.The Ce film layer has a double-layer film structure,the upper layer is an oxide of cerium,and the underlayer is an oxide of iron.Results revealed that after being immersed in the simulated concrete pore solution,the corrosion resistance of the Ce film was enhanced by self-densification.展开更多
基金supported by National Natural Science Foundation of China(No.91963211No 32401505,No 51872136,No 92363001,No 92463303)+1 种基金National Key Research and Development Program of China(No.2018YFB1105400)Jiangsu Funding Program for Excellent Postdoctoral Talent(No.2022ZB61).
文摘Lightweight structural materials with high strength and toughness are highly desirable for many advanced applications.Wood,as a sustainable structural material,is widely used in engineer-ing due to its abundance and excellent mechanical properties.In this paper,we report a self-densification strategy to develop super-strong wood by reassembling highly aligned wood fibers as functional units and self-densified without the need for hot pressing.The resulting self-densified wood exhibits ultra-high tensile strength(496.1 MPa),flexural strength(392.7 MPa)and impact toughness(75.2 kJ/m^(2)),surpassing those of compressed densified wood and traditional metal materials like aluminum alloys.Notably,the self-densified wood exhibits uniform shrinkage in the cross-section while maintaining its longitudinal dimension.This characteristic leads to an order-of-magnitude enhancement in the overall mechanical performance of the wood,presenting a significant advantage over compressed densified wood.Such super-strong yet lightweight wood has great potential for application as a sustainable engineering material,replacing traditional structural materials such as metals and alloys.
基金financially supported by the National Natural Science Foundation of China(Nos.51771061 and 51571067)the National Basic Research Program of China(No.2014CB643301)+2 种基金the Natural Science Foundation of Heilongjiang Province,China(No.E2016022)the Fundamental Research Founds for the Central Universities(No.HEUCFG201838)the Key Laboratory of Superlight Materials and Surface Technology(Harbin Engineering University)。
文摘A cerium film was prepared on the surface of rebar by chemical conversion method to enhance its corrosion resistance.The film in the simulated concrete pore solution was measured by electrochemical method,transmission electron microscope(TEM)and X-ray photoelectron spectroscopy(XPS).The effect of temperature on film formation was studied,and the optimum temperature was determined at 35℃.The film produced by too high formation temperature has more defects,resulting in the lower corrosion resistance.The Ce film resistance increased with time evolution until 800 h,then decreased and stabilized.The Ce film layer has a double-layer film structure,the upper layer is an oxide of cerium,and the underlayer is an oxide of iron.Results revealed that after being immersed in the simulated concrete pore solution,the corrosion resistance of the Ce film was enhanced by self-densification.
