Durability design of recycled high performance concrete(RHPC) is fundamental for improving the use rate and level of concrete waste as coarse recycled aggregate(CRA). We discussed a frostdurability-based mix propo...Durability design of recycled high performance concrete(RHPC) is fundamental for improving the use rate and level of concrete waste as coarse recycled aggregate(CRA). We discussed a frostdurability-based mix proportion design method for RHPC using 100 % CRA and natural sand. Five groups of RHPC mixes with five strength grades(40, 50, 60, 70 and 80 MPa) were produced using CRA with four quality classes, and their workability, 28 d compressive strengths and frost resistances(measured by the compressive strength loss ratio and the relative dynamic modulus of elasticity) were tested. Relationships between the 28 d compressive strength, the frost resistance and the CRA quality characteristic parameter, water absorption, were then developed. The criterion of a CRA maximum water absorption limit value for RHPC was suggested, independent of its source and quality class. The results show that all RHPC mixes achieve the expected target workability, strength, and frost durability. The research results demonstrate that the application of the proposed method does not require trial testing prior to use.展开更多
In order to investigate water and chloride ion transport in damaged concrete, three types of concrete were prepared, freeze-thawing(F-T) cycling and compressive loading were adopted to induce damage to concrete. Ult...In order to investigate water and chloride ion transport in damaged concrete, three types of concrete were prepared, freeze-thawing(F-T) cycling and compressive loading were adopted to induce damage to concrete. Ultrasonic pulse velocity technique was used for evaluating the damage degree of concrete, and the defects of damaged concrete were also detected by X-CT. Water absorption and chloride ion penetrability were used for describing the transport properties of damaged concrete. Effects of damage degree on the water absorption rate and chloride ion penetrability were investigated in detail and the relationships were also established. The results show that the water absorption of concrete makes various responses to damage degree due to the difference of concrete type and damage method. For same concrete with similar damage degree, the water absorption rate of F-T damaged concrete is usually larger than that of concrete damaged by loading. The chloride ion penetrability of damaged concrete increases linearly with increasing damage degree, which is more sensitive to damage degree if the original penetrability of sound concrete is higher.展开更多
PHOBOTEX~? RSY durable water repellent delivers best-in-class performance to support the industry's shift to non-fluorinated formulations Continuing to lead the textile sector’s transition to more sustainable and...PHOBOTEX~? RSY durable water repellent delivers best-in-class performance to support the industry's shift to non-fluorinated formulations Continuing to lead the textile sector’s transition to more sustainable and eco-friendly business models,Huntsman Textile Effects has introduced the new PHOBOTEX~?RSY non-fluorinated durable water repellent(DWR)that raises the standard for repellency especially on high-performance synthetic textiles.This new product will allow brands and retailers to meet global demand for eco-friendly clothing that require extreme rain-and stain-protection.展开更多
Effects of Zn/P ratio on the structures and properties of glasses with the general composition of (80-x)ZnO-20Fe2O3-xP2O5 (x=40, 45, 50, 55, 60) (molar fraction, %) were investigated. Glass structure was measure...Effects of Zn/P ratio on the structures and properties of glasses with the general composition of (80-x)ZnO-20Fe2O3-xP2O5 (x=40, 45, 50, 55, 60) (molar fraction, %) were investigated. Glass structure was measured by infrared absorption spectrum. Glass density (/9) was measured by the Archimedes method. Coefficients of thermal expansion (a) and characterization temperature were obtained by a dilatometer. Water durability of each glass was estimated from the dissolution rate (DR)in water at 90 ℃ for 24 h. With increasing Zn/P ratio, water durability of zinc-iron phosphate glasses increases dramatically without large increase in the characterization temperature. (80-x)ZnO-20Fe2O3-xP2O5 glasses with 0.3≤Zn/P≤0.5 are suit for low-to-mid temperature sealing application for substrates with a〈8.0× 10^-6℃^-1.展开更多
The hydrokinetic energy of river current,as one of the essential and widespread renewable energies,is difficult to be harvested in low flow velocity and shallow water areas.In this work,a three-dimensional(3D)fully-en...The hydrokinetic energy of river current,as one of the essential and widespread renewable energies,is difficult to be harvested in low flow velocity and shallow water areas.In this work,a three-dimensional(3D)fully-enclosed triboelectric nanogenerator(FETENG)with bionic fish-like structure for harvesting hydrokinetic energy is reported,which is comprised of the triboelectric powergeneration unit,bionic fish-like structure and connection unit.Through the bionic structure,the FE-TENG realizes zero head power generation in shallow water with low flow velocity.What’s more,the effect of external excitations and bionic structures on the electrical performance are systematically studied in this work.The FE-TENG can generate peak power density of 7 and 0.36 W/m^(3)respectively under the simulated swing state with frequency of 1.25 Hz and simulated river current with flow velocity of 0.81 m/s.In practical applications,due to the 3D fully-enclosed design,the FE-TENG immersed in water for 35 days demonstrates excellent immersion durability with undiminished electrical performance.Therefore,the work proposes an efficient method realizing zero head power generation,and provides a good candidate for long-term service in the river current.展开更多
In this study,a durable superhydrophobic/superoleophilic melamine foam was fabricated by a facile and rapid one-step thiol-ene click chemistry and Michael addition reaction,which demonstrated excellent robustness in o...In this study,a durable superhydrophobic/superoleophilic melamine foam was fabricated by a facile and rapid one-step thiol-ene click chemistry and Michael addition reaction,which demonstrated excellent robustness in oil/water separation.First,1H,1H,2H-perfluoro-1-hexene reacted with thiol-functionalized polyhedral oligomeric silsesquioxane via the thiol-ene click chemistry to obtain a fluorinated thiol-functionalized polyhedral oligomeric silsesquioxane solution.Subsequently,the melamine foam was immersed to the solution system to form nanoaggregates on the melamine foam surface by the Michael addition reaction in the presence of ultraviolet light.The micro/nano rough structure and low surface energy of the nanoaggregates layer endowed the pristine melamine foam with superhydrophobicity;the water contact angle was greater than 150°.More importantly,the as-prepared melamine foam could withstand harsh conditions,such as a corrosive solution environment,strong ultraviolet light,mechanical compression,high and low temperature exposure,and ultrasonic washing.Driven by gravity,the as-prepared melamine foam could efficiently separate the oil/water mixtures and maintain 98%separation efficiency at high and low temperatures.In addition,it maintained the desirable absorption capability in different oil/organic solvents even after 15 absorption cycles.Accordingly,this facile,low-cost,and robust onestep method provides important support for the superhydrophobic oil/water separation field.展开更多
基金Funded by the National Natural Science Foundation of China(No.51278073)Prospective Joint Research Project of Jiangsu Province(No.BY2015027-23)State Key Laboratory for Geo Mechanics and Deep Underground Engineering,China University of Mining&Technology(No.SKLGDUEK1704)
文摘Durability design of recycled high performance concrete(RHPC) is fundamental for improving the use rate and level of concrete waste as coarse recycled aggregate(CRA). We discussed a frostdurability-based mix proportion design method for RHPC using 100 % CRA and natural sand. Five groups of RHPC mixes with five strength grades(40, 50, 60, 70 and 80 MPa) were produced using CRA with four quality classes, and their workability, 28 d compressive strengths and frost resistances(measured by the compressive strength loss ratio and the relative dynamic modulus of elasticity) were tested. Relationships between the 28 d compressive strength, the frost resistance and the CRA quality characteristic parameter, water absorption, were then developed. The criterion of a CRA maximum water absorption limit value for RHPC was suggested, independent of its source and quality class. The results show that all RHPC mixes achieve the expected target workability, strength, and frost durability. The research results demonstrate that the application of the proposed method does not require trial testing prior to use.
基金Funded by the Major State Basic Research Development Program of China(973 Program)(No.2015CB655102)the National Natural Science Foundation of China(Nos.51178106,51378116&51408597)the Scientific and Technological Research and Development plan of China Railway Corporation(No.2013G001-A-2)
文摘In order to investigate water and chloride ion transport in damaged concrete, three types of concrete were prepared, freeze-thawing(F-T) cycling and compressive loading were adopted to induce damage to concrete. Ultrasonic pulse velocity technique was used for evaluating the damage degree of concrete, and the defects of damaged concrete were also detected by X-CT. Water absorption and chloride ion penetrability were used for describing the transport properties of damaged concrete. Effects of damage degree on the water absorption rate and chloride ion penetrability were investigated in detail and the relationships were also established. The results show that the water absorption of concrete makes various responses to damage degree due to the difference of concrete type and damage method. For same concrete with similar damage degree, the water absorption rate of F-T damaged concrete is usually larger than that of concrete damaged by loading. The chloride ion penetrability of damaged concrete increases linearly with increasing damage degree, which is more sensitive to damage degree if the original penetrability of sound concrete is higher.
文摘PHOBOTEX~? RSY durable water repellent delivers best-in-class performance to support the industry's shift to non-fluorinated formulations Continuing to lead the textile sector’s transition to more sustainable and eco-friendly business models,Huntsman Textile Effects has introduced the new PHOBOTEX~?RSY non-fluorinated durable water repellent(DWR)that raises the standard for repellency especially on high-performance synthetic textiles.This new product will allow brands and retailers to meet global demand for eco-friendly clothing that require extreme rain-and stain-protection.
基金Project(7602110340) supported by the Postdoctoral Science Foundation of Central South University, ChinaProject(721500277)supported by the Fundamental Research Funds for the Central Universities of China
文摘Effects of Zn/P ratio on the structures and properties of glasses with the general composition of (80-x)ZnO-20Fe2O3-xP2O5 (x=40, 45, 50, 55, 60) (molar fraction, %) were investigated. Glass structure was measured by infrared absorption spectrum. Glass density (/9) was measured by the Archimedes method. Coefficients of thermal expansion (a) and characterization temperature were obtained by a dilatometer. Water durability of each glass was estimated from the dissolution rate (DR)in water at 90 ℃ for 24 h. With increasing Zn/P ratio, water durability of zinc-iron phosphate glasses increases dramatically without large increase in the characterization temperature. (80-x)ZnO-20Fe2O3-xP2O5 glasses with 0.3≤Zn/P≤0.5 are suit for low-to-mid temperature sealing application for substrates with a〈8.0× 10^-6℃^-1.
基金the support received from the National Key R&D Project from the Minister of Science and Technology(Nos.2021YFA1201601 and 2021YFA1201604)the Natural Science Foundation of Beijing Municipality(No.3222023)。
文摘The hydrokinetic energy of river current,as one of the essential and widespread renewable energies,is difficult to be harvested in low flow velocity and shallow water areas.In this work,a three-dimensional(3D)fully-enclosed triboelectric nanogenerator(FETENG)with bionic fish-like structure for harvesting hydrokinetic energy is reported,which is comprised of the triboelectric powergeneration unit,bionic fish-like structure and connection unit.Through the bionic structure,the FE-TENG realizes zero head power generation in shallow water with low flow velocity.What’s more,the effect of external excitations and bionic structures on the electrical performance are systematically studied in this work.The FE-TENG can generate peak power density of 7 and 0.36 W/m^(3)respectively under the simulated swing state with frequency of 1.25 Hz and simulated river current with flow velocity of 0.81 m/s.In practical applications,due to the 3D fully-enclosed design,the FE-TENG immersed in water for 35 days demonstrates excellent immersion durability with undiminished electrical performance.Therefore,the work proposes an efficient method realizing zero head power generation,and provides a good candidate for long-term service in the river current.
基金supported by the National Key Research and Development Program(Grant No.2017YFB0307700)the Department of Scientific and Technology of Zhejiang Province(Grant No.LGG19E030007)the Project for the Innovation of High Level Returned Overseas Scholars(or team)in Hangzhou.We also thank the financial support from Department of Scientific and Technology of Yunnan Province(Grant No.202002AB080002).
文摘In this study,a durable superhydrophobic/superoleophilic melamine foam was fabricated by a facile and rapid one-step thiol-ene click chemistry and Michael addition reaction,which demonstrated excellent robustness in oil/water separation.First,1H,1H,2H-perfluoro-1-hexene reacted with thiol-functionalized polyhedral oligomeric silsesquioxane via the thiol-ene click chemistry to obtain a fluorinated thiol-functionalized polyhedral oligomeric silsesquioxane solution.Subsequently,the melamine foam was immersed to the solution system to form nanoaggregates on the melamine foam surface by the Michael addition reaction in the presence of ultraviolet light.The micro/nano rough structure and low surface energy of the nanoaggregates layer endowed the pristine melamine foam with superhydrophobicity;the water contact angle was greater than 150°.More importantly,the as-prepared melamine foam could withstand harsh conditions,such as a corrosive solution environment,strong ultraviolet light,mechanical compression,high and low temperature exposure,and ultrasonic washing.Driven by gravity,the as-prepared melamine foam could efficiently separate the oil/water mixtures and maintain 98%separation efficiency at high and low temperatures.In addition,it maintained the desirable absorption capability in different oil/organic solvents even after 15 absorption cycles.Accordingly,this facile,low-cost,and robust onestep method provides important support for the superhydrophobic oil/water separation field.