Inorganic lead halide perovskite nanocrystals(NCs)with superior photoelectric properties are expected to have excellent performance in many fields.However,the anion exchange changes their features and is unfavorable f...Inorganic lead halide perovskite nanocrystals(NCs)with superior photoelectric properties are expected to have excellent performance in many fields.However,the anion exchange changes their features and is unfavorable for their applications in many fields.Hence,impeding anion exchange is important for improving the composition stability of inorganic lead halide perovskite NCs.Herein,CsPb X3(X=Cl,Br)NCs are coated with Cs4PbX6 shell to impede anion exchange and reduce anion mobility.The Cs4PbX6 shell is facily fabricated on CsPbX3 NCs through high temperature injection method.Anion exchange experiments demonstrate that the Cs4 PbX6 shell completely encapsulates CsPbX3 NCs and greatly improves the composition stability of CsPbX3 NCs.Moreover,our work also sheds light on the potential design approaches of various heterostructures to expand the application of CsPbM3(M=Cl,Br,I)NCs.展开更多
There are some unique techniques in the Chinese traditional silk production. 2-2 patterning method is such one suggested by foreign scholars. But this paper gives a more extensive concept, G-G method, which includes t...There are some unique techniques in the Chinese traditional silk production. 2-2 patterning method is such one suggested by foreign scholars. But this paper gives a more extensive concept, G-G method, which includes the 2-2 method after studying more fabrics from the Shang. to the Five Dynasties. Finally, the paper discusses the truth of G-G method the (?) applied in, and some characteristics of G-G method.展开更多
Due to the low cost,high theoretical capacity,and environmental friendliness,manganese-based cathodes are regarded as promising alternatives for aqueous zinc ion batteries(AZIBs).However,the practicality of the zinc-m...Due to the low cost,high theoretical capacity,and environmental friendliness,manganese-based cathodes are regarded as promising alternatives for aqueous zinc ion batteries(AZIBs).However,the practicality of the zinc-manganese system is faced with great challenges,such as the inevitable structural collapse of the cathode and controversial energy storage mechanisms.Herein,we propose a novel concept of spatial deposition mechanism through the addition of MnSO_(4) additives in the Mn O-pillared graphene blocks(G-MnO).The covalent interface between MnO nanoparticles and multilayered graphene nanosheets can construct an in-built micro-electric field,which is beneficial for consecutive electron transfer(in both horizontal and vertical directions).On this basis,the surficial activity of MnO confined in the interlayered nano-space is greatly enhanced and provides enough spatial deposition and subsequent reaction site for MnSO_(4) additives,thus firstly extending the surficial controlled process to stereoscopic space,effectively improving the electrochemical performance of AZIBs.Therefore,the assembled Zn//G-Mn O battery exhibits an excellent rate capability of 281.5 mAhg^(-1)at 0.1 A g^(-1)and 106 mAhg^(-1)at 20 Ag^(-1),and impressive cycling stability(93 mAhg^(-1)remaining after 5,000 cycles).This finding may provide a new opportunity for the rational design of surficial controlled energy storage and conversion devices.展开更多
One strategy to reduce CO_(2)emissions from cement production is to reduce the amount of Portland cement produced by replacing it with supplementary cementitious materials(SCMs).Biochar is a potential SCM that is an e...One strategy to reduce CO_(2)emissions from cement production is to reduce the amount of Portland cement produced by replacing it with supplementary cementitious materials(SCMs).Biochar is a potential SCM that is an eco-friendly and stable porous pyrolytic material.However,the effects of biochar addition on the performances of Portland cement composites are not fully understood.This meta-analysis investigated the impact of biochar addition on the 7-and 28-day compressive strength of Portland cement composites based on 606 paired observations.Biochar feedstock type,pyrolysis conditions,pre-treatments and modifications,biochar dosage,and curing type all influenced the compressive strength of Portland cement composites.Biochars obtained from plant-based feedstocks(except rice and hardwood)improved the 28-day compressive strength of Portland cement composites by 3-13%.Biochars produced at pyrolysis temperatures higher than 450°C,with a heating rate of around 10 C min-1,increased the 28-day compressive strength more effectively.Furthermore,the addition of biochar with small particle sizes increased the compressive strength of Portland cement composites by 2-7%compared to those without biochar addition.Biochar dosage of<2.5%of the binder weight enhanced both compressive strengths,and common curing methods maintained the effect of biochar addition.However,when mixing the cement,adding fine and coarse aggregates such as sand and gravel affects the concrete and mortar’s compressive strength,diminishing the effect of biochar addition and making the biochar effect nonsignificant.We concluded that appropriate biochar addition could maintain or enhance the mechanical performance of Portland cement composites,and future research should explore the mechanisms of biochar effects on the performance of cement composites.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11474018,61704007,and 61575019)the National Key Research and Development Program of China(Grant No.2017YFB0404501)+1 种基金the Fundamental Research Funds for the Central Universities,China(Grant No.2017RC034)the Shenzhen China Star Optoelectronics Technology Co.,Ltd
文摘Inorganic lead halide perovskite nanocrystals(NCs)with superior photoelectric properties are expected to have excellent performance in many fields.However,the anion exchange changes their features and is unfavorable for their applications in many fields.Hence,impeding anion exchange is important for improving the composition stability of inorganic lead halide perovskite NCs.Herein,CsPb X3(X=Cl,Br)NCs are coated with Cs4PbX6 shell to impede anion exchange and reduce anion mobility.The Cs4PbX6 shell is facily fabricated on CsPbX3 NCs through high temperature injection method.Anion exchange experiments demonstrate that the Cs4 PbX6 shell completely encapsulates CsPbX3 NCs and greatly improves the composition stability of CsPbX3 NCs.Moreover,our work also sheds light on the potential design approaches of various heterostructures to expand the application of CsPbM3(M=Cl,Br,I)NCs.
文摘There are some unique techniques in the Chinese traditional silk production. 2-2 patterning method is such one suggested by foreign scholars. But this paper gives a more extensive concept, G-G method, which includes the 2-2 method after studying more fabrics from the Shang. to the Five Dynasties. Finally, the paper discusses the truth of G-G method the (?) applied in, and some characteristics of G-G method.
基金supported by the National Natural Science Foundation of China(52202311,52272259)the Key Basic Research Projects of Natural Science Foundation of Shandong Province(ZR2019ZD51)the Taishan Scholar Project of Shandong Province(ts20190922)。
文摘Due to the low cost,high theoretical capacity,and environmental friendliness,manganese-based cathodes are regarded as promising alternatives for aqueous zinc ion batteries(AZIBs).However,the practicality of the zinc-manganese system is faced with great challenges,such as the inevitable structural collapse of the cathode and controversial energy storage mechanisms.Herein,we propose a novel concept of spatial deposition mechanism through the addition of MnSO_(4) additives in the Mn O-pillared graphene blocks(G-MnO).The covalent interface between MnO nanoparticles and multilayered graphene nanosheets can construct an in-built micro-electric field,which is beneficial for consecutive electron transfer(in both horizontal and vertical directions).On this basis,the surficial activity of MnO confined in the interlayered nano-space is greatly enhanced and provides enough spatial deposition and subsequent reaction site for MnSO_(4) additives,thus firstly extending the surficial controlled process to stereoscopic space,effectively improving the electrochemical performance of AZIBs.Therefore,the assembled Zn//G-Mn O battery exhibits an excellent rate capability of 281.5 mAhg^(-1)at 0.1 A g^(-1)and 106 mAhg^(-1)at 20 Ag^(-1),and impressive cycling stability(93 mAhg^(-1)remaining after 5,000 cycles).This finding may provide a new opportunity for the rational design of surficial controlled energy storage and conversion devices.
基金supported by a Natural Sciences and Engineering Research Council of Canada(NSERC)Alliance grant(ALLRP 571094-21)and Innovative Reduction Strategies Inc.
文摘One strategy to reduce CO_(2)emissions from cement production is to reduce the amount of Portland cement produced by replacing it with supplementary cementitious materials(SCMs).Biochar is a potential SCM that is an eco-friendly and stable porous pyrolytic material.However,the effects of biochar addition on the performances of Portland cement composites are not fully understood.This meta-analysis investigated the impact of biochar addition on the 7-and 28-day compressive strength of Portland cement composites based on 606 paired observations.Biochar feedstock type,pyrolysis conditions,pre-treatments and modifications,biochar dosage,and curing type all influenced the compressive strength of Portland cement composites.Biochars obtained from plant-based feedstocks(except rice and hardwood)improved the 28-day compressive strength of Portland cement composites by 3-13%.Biochars produced at pyrolysis temperatures higher than 450°C,with a heating rate of around 10 C min-1,increased the 28-day compressive strength more effectively.Furthermore,the addition of biochar with small particle sizes increased the compressive strength of Portland cement composites by 2-7%compared to those without biochar addition.Biochar dosage of<2.5%of the binder weight enhanced both compressive strengths,and common curing methods maintained the effect of biochar addition.However,when mixing the cement,adding fine and coarse aggregates such as sand and gravel affects the concrete and mortar’s compressive strength,diminishing the effect of biochar addition and making the biochar effect nonsignificant.We concluded that appropriate biochar addition could maintain or enhance the mechanical performance of Portland cement composites,and future research should explore the mechanisms of biochar effects on the performance of cement composites.
