Osteochondral allografting has been proved to be a useful method to treat diseased or damaged areas of joint surfaces. Operational long-term stocks of grafts which supply a buffer between procurement and utilization w...Osteochondral allografting has been proved to be a useful method to treat diseased or damaged areas of joint surfaces. Operational long-term stocks of grafts which supply a buffer between procurement and utilization would contribute to the commercialization or industrialization of this technology. Vitrification has been thought to be a promising method for successful preservation of articular cartilage （AC）, but high concentration cryoprotectants （CPAs） are used which may cause high cellular toxicity. An effective way to reduce CPA toxioity is to increase CPA concen- tration gradually while the temperature is lowered. Understanding the mechanism of （31~A permeation at subzero temperatures is important for designing the cryopreservation protocol. In this research, the permeation of dimethyl sulfoxide （MezSO） in ovine AC at subzero temperatures was studied experimentally. Pretreated AC discs were ex- posed in Me2SO solutions for different time （0, 5, 15, 30, 50, 80, and 120 min） at three temperature levels （-10, -20, and -30℃）. The Me2SO concentration within the tissue was determined by ultraviolet （UV） spectrophotometry. The diffusion coefficients were estimated to be 0.85×10-6, 0.48×10-8, and 0.27×10-6 cm2/s at -10, -20, and -,30℃, respectively, and the corresponding activation energy was 29.23 kJ/mol. Numerical simulation was performed to com- pare two Me2SO addition protocols, and the results demonstrated that the total loading duration could be effectively reduced with the knowledge of permeation kinetics.展开更多
Layered Ni-rich cathode materials,LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)(NCM622),are synthesized via solid reaction assisted with a plasma milling pretreatment,which is resulted in lowering sintering temperatures for solid p...Layered Ni-rich cathode materials,LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)(NCM622),are synthesized via solid reaction assisted with a plasma milling pretreatment,which is resulted in lowering sintering temperatures for solid precursors.The plasma milling pretreated NCM622 cathode material sintered at 780℃(named as PM-780)demonstrates good cycling stability at both room and subzero temperatures.Specifically,the PM-780 cathode delivers an initial discharge capacity of 171.2 mAh g^(-1) and a high capacity retention of 99.7%after 300 cycles with current rate of 90 mA g^(-1) at 30℃,while stable capacities of 120.3 and 94.0 m Ah g^(-1) can be remained at-10℃and-20℃in propylene carbonate contained electrolyte,respectively.In-situ XRD together with XPS and SEM reveal that the NCM622 cycled at-10℃presented better structural stability and more intact interface than that of cathodes cycled at 30℃.It is also found that subzero temperatures only limit the discharge potential of NCM622 without destroying its structure during cycling since it still exhibits high discharge capacity at 30℃after cycled at subzero temperatures.This work may expand the knowledge about the low-temperature characteristics of layered cathode materials for Li-ion batteries and lay the foundation for its further applications.展开更多
The compressive strength,hydration products and microstructure of concrete with calcium-enriched fly ash(CEFA) at different temperature were investigated.The result indicates that the hydration products age of 7 d at-...The compressive strength,hydration products and microstructure of concrete with calcium-enriched fly ash(CEFA) at different temperature were investigated.The result indicates that the hydration products age of 7 d at-15 ℃ are mainly ettringite and C-S-H,and fly ash particles remain original state.Standard curing was adapted after 7 d curing at-15 ℃.At the age of 35 d,C-S-H was found on the surface of fly ash particles.The hydration product of CEFA is mainly C-S-H gel,which can densify the microstructure of concrete.展开更多
Porous organic polymers(POPs)have attracted extensive interest due to their structural diversity and predesigned functionality.However,the majority of POPs are synthesized as insoluble and unprocessable powders,which ...Porous organic polymers(POPs)have attracted extensive interest due to their structural diversity and predesigned functionality.However,the majority of POPs are synthesized as insoluble and unprocessable powders,which greatly impede their advanced applications because of limited mass transport and inadaptation for device integration.Herein,we report a controlled synthetic strategy of macroscopic POP gels by a cation-stabilized colloidal formation mechanism,which is widely adaptable to a large variety of tetra-/tri-amino build blocks for the synthesis of Tröger’s base-linked POP gels,aerogels,and ionic gels.The POP gels combined the integrated advantages of hierarchically porous structures and tailorable mechanical stiffness,whereas they could load substantial amounts of phosphoric acids and construct unimpeded transport pathways for proton conduction,exhibiting unprecedented proton conductivity at subzero temperatures.Our strategy offers a new solution to the intractable processing issues of POPs toward device applications with cutting-edge performances.展开更多
基金supported by the National Natural Science Foundation of China (No. 50606032)the Graduate Innovation Research Program of Zhejiang Province (No. YK2008020), China
文摘Osteochondral allografting has been proved to be a useful method to treat diseased or damaged areas of joint surfaces. Operational long-term stocks of grafts which supply a buffer between procurement and utilization would contribute to the commercialization or industrialization of this technology. Vitrification has been thought to be a promising method for successful preservation of articular cartilage （AC）, but high concentration cryoprotectants （CPAs） are used which may cause high cellular toxicity. An effective way to reduce CPA toxioity is to increase CPA concen- tration gradually while the temperature is lowered. Understanding the mechanism of （31~A permeation at subzero temperatures is important for designing the cryopreservation protocol. In this research, the permeation of dimethyl sulfoxide （MezSO） in ovine AC at subzero temperatures was studied experimentally. Pretreated AC discs were ex- posed in Me2SO solutions for different time （0, 5, 15, 30, 50, 80, and 120 min） at three temperature levels （-10, -20, and -30℃）. The Me2SO concentration within the tissue was determined by ultraviolet （UV） spectrophotometry. The diffusion coefficients were estimated to be 0.85×10-6, 0.48×10-8, and 0.27×10-6 cm2/s at -10, -20, and -,30℃, respectively, and the corresponding activation energy was 29.23 kJ/mol. Numerical simulation was performed to com- pare two Me2SO addition protocols, and the results demonstrated that the total loading duration could be effectively reduced with the knowledge of permeation kinetics.
基金supported by the National Natural Science Foundation of China(No.51671088,51621001,51822104 and 51831009)the Guangzhou Science and Technology Plan Projects(No.201904020018)the Fundamental Research Funds for the Central Universities in South China University of Technology(No.2019CG24)。
文摘Layered Ni-rich cathode materials,LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)(NCM622),are synthesized via solid reaction assisted with a plasma milling pretreatment,which is resulted in lowering sintering temperatures for solid precursors.The plasma milling pretreated NCM622 cathode material sintered at 780℃(named as PM-780)demonstrates good cycling stability at both room and subzero temperatures.Specifically,the PM-780 cathode delivers an initial discharge capacity of 171.2 mAh g^(-1) and a high capacity retention of 99.7%after 300 cycles with current rate of 90 mA g^(-1) at 30℃,while stable capacities of 120.3 and 94.0 m Ah g^(-1) can be remained at-10℃and-20℃in propylene carbonate contained electrolyte,respectively.In-situ XRD together with XPS and SEM reveal that the NCM622 cycled at-10℃presented better structural stability and more intact interface than that of cathodes cycled at 30℃.It is also found that subzero temperatures only limit the discharge potential of NCM622 without destroying its structure during cycling since it still exhibits high discharge capacity at 30℃after cycled at subzero temperatures.This work may expand the knowledge about the low-temperature characteristics of layered cathode materials for Li-ion batteries and lay the foundation for its further applications.
文摘The compressive strength,hydration products and microstructure of concrete with calcium-enriched fly ash(CEFA) at different temperature were investigated.The result indicates that the hydration products age of 7 d at-15 ℃ are mainly ettringite and C-S-H,and fly ash particles remain original state.Standard curing was adapted after 7 d curing at-15 ℃.At the age of 35 d,C-S-H was found on the surface of fly ash particles.The hydration product of CEFA is mainly C-S-H gel,which can densify the microstructure of concrete.
基金supported by the National Natural Science Foundation of China (grant nos.21975078,21971074,22241501,and 92261117)the Fundamental Research Funds for the Central Universitiesthe start-up foundation of Sichuan University.
文摘Porous organic polymers(POPs)have attracted extensive interest due to their structural diversity and predesigned functionality.However,the majority of POPs are synthesized as insoluble and unprocessable powders,which greatly impede their advanced applications because of limited mass transport and inadaptation for device integration.Herein,we report a controlled synthetic strategy of macroscopic POP gels by a cation-stabilized colloidal formation mechanism,which is widely adaptable to a large variety of tetra-/tri-amino build blocks for the synthesis of Tröger’s base-linked POP gels,aerogels,and ionic gels.The POP gels combined the integrated advantages of hierarchically porous structures and tailorable mechanical stiffness,whereas they could load substantial amounts of phosphoric acids and construct unimpeded transport pathways for proton conduction,exhibiting unprecedented proton conductivity at subzero temperatures.Our strategy offers a new solution to the intractable processing issues of POPs toward device applications with cutting-edge performances.
