Potassium-ion batteries(KIBs)are a potential candidate to lithium-ion batteries(LIBs)but possess unsatisfactory capacity and rate properties.Herein,the metallic cobalt selenide quantum dots(Co0.85Se-QDs)encapsulated i...Potassium-ion batteries(KIBs)are a potential candidate to lithium-ion batteries(LIBs)but possess unsatisfactory capacity and rate properties.Herein,the metallic cobalt selenide quantum dots(Co0.85Se-QDs)encapsulated in mesoporous carbon matrix were designed via a direct hydrothermal method.Specifically,the cobalt selenide/carbon composite(Co0.85Se-QDs/C)possesses tertiary hierarchical structure,which is the primary quantum dots,the secondary petals flake,and the tertiary hollow micropolyhedron framework.Co0.85Se-QDs are homogenously embedded into the carbon petals flake,which constitute the hollow polyhedral framework.This unique structure can take the advantages of both nanoscale and microscale features:Co0.85Se-QDs can expand in a multidimensional and ductile carbon matrix and reduce the K-intercalation stress in particle dimensions;the micropetals can restrain the agglomeration of active materials and promote the transportation of potassium ion and electron.In addition,the hollow carbon framework buffers volume expansion,maintains the structural integrity,and increases the electronic conductivity.Benefiting from this tertiary hierarchical structure,outstanding K-storage performance(402 mAh g?1 after 100 cycles at 50 mA g?1)is obtained when Co0.85Se-QDs/C is used as KIBs anode.More importantly,the selenization process in this work is newly reported and can be generally extended to prepare other quantum dots encapsulated in edge-limited frameworks for excellent energy storage.展开更多
Owing to adjustable thermal expansion performance, BaO–CaO–Al_2O_3–B_2O_3–SiO_2(BCABS) glass has a promising commercialization prospect for intermediate temperature-solid oxide fuel cells(IT-SOFCs) sealing. Herein...Owing to adjustable thermal expansion performance, BaO–CaO–Al_2O_3–B_2O_3–SiO_2(BCABS) glass has a promising commercialization prospect for intermediate temperature-solid oxide fuel cells(IT-SOFCs) sealing. Herein, Al_2O_3 with two different contents was added into the same glass formulation, referred to as A and B glass, respectively. In terms of the non-isothermal crystallization kinetic behavior, the effect of Al_2O_3 as the unique intermediate was innovatively studied on the long-term performance of BCABS sealing glass. After the heat treatment at 1023 K for 100 h, the change of the network structure and the expansion coefficient of the glass were characterized. The results showed that the addition of Al_2O_3 as a network forming body could enhance the structure of glass, and increase the activation energy for glass transition, which could effectively inhibit the crystallization ability of sealing glass. Therefore, the B glass with the higher Al_2O_3 content showed the better long-term sealing ability, which was greatly beneficial for IT-SOFCs sealing.展开更多
Glaucoma is the second leading cause of blindness after cataract worldwide.However,among irreversible blinding eye diseases,glaucoma is the primary cause(Liang et al.,2011).To date,most studies have indicated that gla...Glaucoma is the second leading cause of blindness after cataract worldwide.However,among irreversible blinding eye diseases,glaucoma is the primary cause(Liang et al.,2011).To date,most studies have indicated that glaucoma is not only an ocular disease,but also an optic nerve disease.In particular,primary open-angle glaucoma(POAG)is characterized by insidious onset,painless visual impairment,and complicated pathological mechanism,and patients with such condition require long-term follow-up.However,the underlying cause of POAG remains unclear,and there are several theories about its exact etiology.Some mechanisms have presented underlying optic nerve damage,which include the mechanical theory,vascular theory,and the in・volvement of other factors.展开更多
基金financially supported by Beijing Natural Science Foundation(No.2192034)China Postdoctoral Science Foundation(No.2018M631335)National Key R&D Program of China(No.2018YFB0905600).
文摘Potassium-ion batteries(KIBs)are a potential candidate to lithium-ion batteries(LIBs)but possess unsatisfactory capacity and rate properties.Herein,the metallic cobalt selenide quantum dots(Co0.85Se-QDs)encapsulated in mesoporous carbon matrix were designed via a direct hydrothermal method.Specifically,the cobalt selenide/carbon composite(Co0.85Se-QDs/C)possesses tertiary hierarchical structure,which is the primary quantum dots,the secondary petals flake,and the tertiary hollow micropolyhedron framework.Co0.85Se-QDs are homogenously embedded into the carbon petals flake,which constitute the hollow polyhedral framework.This unique structure can take the advantages of both nanoscale and microscale features:Co0.85Se-QDs can expand in a multidimensional and ductile carbon matrix and reduce the K-intercalation stress in particle dimensions;the micropetals can restrain the agglomeration of active materials and promote the transportation of potassium ion and electron.In addition,the hollow carbon framework buffers volume expansion,maintains the structural integrity,and increases the electronic conductivity.Benefiting from this tertiary hierarchical structure,outstanding K-storage performance(402 mAh g?1 after 100 cycles at 50 mA g?1)is obtained when Co0.85Se-QDs/C is used as KIBs anode.More importantly,the selenization process in this work is newly reported and can be generally extended to prepare other quantum dots encapsulated in edge-limited frameworks for excellent energy storage.
基金financially supported by the research project of National Natural Science Foundation of China (Grant Nos.51662015 and 51462011)
文摘Owing to adjustable thermal expansion performance, BaO–CaO–Al_2O_3–B_2O_3–SiO_2(BCABS) glass has a promising commercialization prospect for intermediate temperature-solid oxide fuel cells(IT-SOFCs) sealing. Herein, Al_2O_3 with two different contents was added into the same glass formulation, referred to as A and B glass, respectively. In terms of the non-isothermal crystallization kinetic behavior, the effect of Al_2O_3 as the unique intermediate was innovatively studied on the long-term performance of BCABS sealing glass. After the heat treatment at 1023 K for 100 h, the change of the network structure and the expansion coefficient of the glass were characterized. The results showed that the addition of Al_2O_3 as a network forming body could enhance the structure of glass, and increase the activation energy for glass transition, which could effectively inhibit the crystallization ability of sealing glass. Therefore, the B glass with the higher Al_2O_3 content showed the better long-term sealing ability, which was greatly beneficial for IT-SOFCs sealing.
基金funded by the National Key Research and Development Program of China(2017YFB1302703)
文摘Glaucoma is the second leading cause of blindness after cataract worldwide.However,among irreversible blinding eye diseases,glaucoma is the primary cause(Liang et al.,2011).To date,most studies have indicated that glaucoma is not only an ocular disease,but also an optic nerve disease.In particular,primary open-angle glaucoma(POAG)is characterized by insidious onset,painless visual impairment,and complicated pathological mechanism,and patients with such condition require long-term follow-up.However,the underlying cause of POAG remains unclear,and there are several theories about its exact etiology.Some mechanisms have presented underlying optic nerve damage,which include the mechanical theory,vascular theory,and the in・volvement of other factors.