In order to improve the corrosion resistance of carbon steel,Hastelloy coatings were prepared on E235steel substrate by ahigh power diode laser with laser scanning speeds of6and12mm/s,respectively.The interface betwee...In order to improve the corrosion resistance of carbon steel,Hastelloy coatings were prepared on E235steel substrate by ahigh power diode laser with laser scanning speeds of6and12mm/s,respectively.The interface between the coating and substratewas firstly exposed by dissolving off the substrate.Its microstructure,composition and mechanical properties were systemicallystudied.Special“edges”along the grain boundary were found at coating/substrate interface.These“edges”consisted of intergranularcorrosion area and real grain boundary.The interface of coating mainly displayed austenite structure ascribed to the rapidsolidification as well as the dilution of Ni during preparation.Additionally,Hastelloy coating and its interface prepared at the speedof12mm/s showed higher hardness than that prepared at the speed of6mm/s.Grain boundaries had higher friction coefficient thangrains at both coating/substrate interfaces.Moreover,the interface at higher laser scanning speed exhibited smaller grains,lowerdilution rates of Ni and Fe as well as a better tribological property.展开更多
The paper reviews the development of the re-search work on thermal properties of graphene filledpolymer composites.It contains dispersed graphenesheets,3D graphene foam and oriented graphenefilms filled polymer compos...The paper reviews the development of the re-search work on thermal properties of graphene filledpolymer composites.It contains dispersed graphenesheets,3D graphene foam and oriented graphenefilms filled polymer composites and their thermalconductivity,expansion,weight loss and stabili-ty,etc.It also indicates the existing problems展开更多
Indium selenide(InSe),as a wide-bandgap semiconductor,has received extensive attention in the flexible electronics field in recent years due to its exceptional plasticity and promising thermoelectric performance.Howev...Indium selenide(InSe),as a wide-bandgap semiconductor,has received extensive attention in the flexible electronics field in recent years due to its exceptional plasticity and promising thermoelectric performance.However,the low carrier concentration severely limits its thermoelectric performance improvement.In this work,we conducted contrasting strategies that can be employed to increase the carrier concentration of InSe,including bandgap narrowing and heterovalent doping.Specifically,the carrier concentration initially increases as a result of the reduced bandgap upon Te alloying and then slightly decreases due to the weak electronegativity of Te.Whereas Br doping realizes high carrier concentration by pushing the Fermi level into the conduction bands and activating the multiple bands.On the other hand,both Te and Br obviously suppress the thermal conductivity due to the point defect scattering.By contrast,Br doping realizes a higher thermoelectric performance with a maximum ZT of~0.13 at 773 K benefiting from the better optimization of carrier concentration.This work elucidates the strategies for enhancing carrier concentration at anion sites and demonstrates the high efficiency of halogen doping in InSe.Moreover,the carrier concentration of InSe is promising to be further optimized,and future work should focus on employing approaches such as cation doping or secondphase compositing.展开更多
基金Project supported by the New Staff Research Start-up Fund and the Innovation Fund(School of Materials Science and Engineering) of Southwest Petroleum University,China
文摘In order to improve the corrosion resistance of carbon steel,Hastelloy coatings were prepared on E235steel substrate by ahigh power diode laser with laser scanning speeds of6and12mm/s,respectively.The interface between the coating and substratewas firstly exposed by dissolving off the substrate.Its microstructure,composition and mechanical properties were systemicallystudied.Special“edges”along the grain boundary were found at coating/substrate interface.These“edges”consisted of intergranularcorrosion area and real grain boundary.The interface of coating mainly displayed austenite structure ascribed to the rapidsolidification as well as the dilution of Ni during preparation.Additionally,Hastelloy coating and its interface prepared at the speedof12mm/s showed higher hardness than that prepared at the speed of6mm/s.Grain boundaries had higher friction coefficient thangrains at both coating/substrate interfaces.Moreover,the interface at higher laser scanning speed exhibited smaller grains,lowerdilution rates of Ni and Fe as well as a better tribological property.
文摘The paper reviews the development of the re-search work on thermal properties of graphene filledpolymer composites.It contains dispersed graphenesheets,3D graphene foam and oriented graphenefilms filled polymer composites and their thermalconductivity,expansion,weight loss and stabili-ty,etc.It also indicates the existing problems
基金supported by the National Science Fund for Distinguished Young Scholars(No.51925101)the Tencent Xplorer Prize,the National Natural Science Foundation of China(Nos.52371208,52250090,52002042,51772012,51571007and 12374023)+1 种基金Beijing Municipal Natural Science Foundation(JQ18004)the 111 Project(B17002)。
文摘Indium selenide(InSe),as a wide-bandgap semiconductor,has received extensive attention in the flexible electronics field in recent years due to its exceptional plasticity and promising thermoelectric performance.However,the low carrier concentration severely limits its thermoelectric performance improvement.In this work,we conducted contrasting strategies that can be employed to increase the carrier concentration of InSe,including bandgap narrowing and heterovalent doping.Specifically,the carrier concentration initially increases as a result of the reduced bandgap upon Te alloying and then slightly decreases due to the weak electronegativity of Te.Whereas Br doping realizes high carrier concentration by pushing the Fermi level into the conduction bands and activating the multiple bands.On the other hand,both Te and Br obviously suppress the thermal conductivity due to the point defect scattering.By contrast,Br doping realizes a higher thermoelectric performance with a maximum ZT of~0.13 at 773 K benefiting from the better optimization of carrier concentration.This work elucidates the strategies for enhancing carrier concentration at anion sites and demonstrates the high efficiency of halogen doping in InSe.Moreover,the carrier concentration of InSe is promising to be further optimized,and future work should focus on employing approaches such as cation doping or secondphase compositing.
