The in-flight and deposition properties of three types of WC-17 Co powder with different particle densities during a high-velocity oxygen fuel （HVOF） thermal spray process were investigated. Three types of powder ex...The in-flight and deposition properties of three types of WC-17 Co powder with different particle densities during a high-velocity oxygen fuel （HVOF） thermal spray process were investigated. Three types of powder exhibited similar velocity upon impact on the substrate surface. The powder with the lower particle density exhibited a higher temperature upon impingement process, resulting in the generation of a higher flattening ratio. Thus, the coating derived from the powder with the lower particle density possessed superior micro-hardness, porosity and surface roughness. However, the coating with the lowest particle density showed the poorest fracture toughness because of the generation of the largest amount of amorphous phase.展开更多
Pseudo-capacitive negative electrodes remain a major bottleneck in the development of supercapacitor devices with high energy density because the electric double-layer capacitance of the negative electrodes does not m...Pseudo-capacitive negative electrodes remain a major bottleneck in the development of supercapacitor devices with high energy density because the electric double-layer capacitance of the negative electrodes does not match the pseudocapacitance of the corresponding positive electrodes.In the present study,a strategically improved Ni-Co-Mo sulfide is demonstrated to be a promising candidate for high energy density supercapattery devices due to its sustained pseudocapacitive charge storage mechanism.The pseudocapacitive behavior is enhanced when operating under a high current through the addition of a classical Schottky junction next to the electrode-electrolyte interface using atomic layer deposition.The Schottky junction accelerates and decelerates the diffusion of OH-/K+ions during the charging and discharging processes,respectively,to improve the pseudocapacitive behavior.The resulting pseudocapacitive negative electrodes exhibits a specific capacity of 2,114 C g^(-1)at 2 A g^(-1)matches almost that of the positive electrode’s 2,795 C g^(-1)at 3 A g^(-1).As a result,with the equivalent contribution from the positive and negative electrodes,an energy density of 236.1 Wh kg^(-1)is achieved at a power density of 921.9 W kg^(-1)with a total active mass of 15 mg cm-2.This strategy demonstrates the possibility of producing supercapacitors that adapt well to the supercapattery zone of a Ragone plot and that are equal to batteries in terms of energy density,thus,offering a route for further advances in electrochemical energy storage and conversion processes.展开更多
Janus films with asymmetric physical/chemical properties have attracted con siderable attention due to their promising applications in personal thermal management,electronic skin s,sensors,actuators,etc.However,tradit...Janus films with asymmetric physical/chemical properties have attracted con siderable attention due to their promising applications in personal thermal management,electronic skin s,sensors,actuators,etc.However,traditional methods for fabricating Janus films conventionally need the assistance of an interface or auxiliary equipment,which are usually complex and time-consuming.Herein,flexible poly(vinyl alcohol)(PVA)/graphene oxide(GO)/h-BN(recorded as PVA/GO/h-BN)Janus films with thermally,optically,and electrically anisotropic properties are fabricated by a simple density deposition self-assem bly method,which just utilizes the density difference between GO and h-BN during water evaporation.Experimental results show that the two sides of the acquired Janus films have obvious asymmetric characteristics.In the original state of the PVA/GO/h-BN Janus films,the thermal conductivity of the GO side(10.06 W·m^(-1)·K^(-1))is generally lower than that of the h-BN side(10.48W·m^(-1)·K^(-1)).But after GO is reduced,the thermal conductivity of the rGO side reaches 12.17 W·m^(-1)·K^(-1),surpassing that of the h-BN side.In addition,the relative reflectance of the h-BN side of Janus film is also significantly higher than that of the rGO side,and the su rface resistance difference between the two sides is about 4 orders of magnitude.The prepared PVA/GO/h-BN Janus films show great application potential in human thermal management,light conversion switches,and electronic skins.This study provides a simple and versatile strategy for fabricating Janus films with multifunctional(such as thermal,optical,and electrical)anisotropies.展开更多
目的筛选影响胆固醇调节元件结合蛋白1a(cholesterol regulatory element binding protein,SREBP1a)蛋白稳定性的去泛素化酶,并探索其调控机制。方法通过去泛素化酶库筛选显著影响SREBP1a表达的去泛素化酶,免疫蛋白印记实验和实时荧光定...目的筛选影响胆固醇调节元件结合蛋白1a(cholesterol regulatory element binding protein,SREBP1a)蛋白稳定性的去泛素化酶,并探索其调控机制。方法通过去泛素化酶库筛选显著影响SREBP1a表达的去泛素化酶,免疫蛋白印记实验和实时荧光定量PCR(qRT-PCR)评估去泛素化酶对SREBP1a以及升脂基因表达的影响;通过红色荧光蛋白标记人源低密度脂蛋白(human Dil-low density lipoprotein,Human Dil-LDL)摄取和油红O染色等实验技术检测细胞摄取低密度脂蛋白(LDL)和脂质沉积情况。结果去泛素化酶库筛选发现泛素特异肽酶37(ubiquitin specific peptidase 37,USP37)可显著增加肝细胞SREBP1a蛋白表达水平,促进胆固醇摄取及脂质沉积。USP37基因敲除可显著降低SREBP1a蛋白表达水平,抑制升脂基因表达及脂质沉积。结论去泛素化酶USP37通过稳定SREBP1a蛋白表达,促进胆固醇摄取及脂质沉积,揭示了SREBP1a翻译后调控的新模式。展开更多
针对背沟道刻蚀(Back Channel Etch,BCE)技术的非晶铟镓锌氧化物(a-IGZO)薄膜晶体管(Thin Film Transistor,TFTs),建立了一种高浓度掺杂态密度模型(High Concentration Doping Density Of States model,HCD-DOS model),并通过数值模拟...针对背沟道刻蚀(Back Channel Etch,BCE)技术的非晶铟镓锌氧化物(a-IGZO)薄膜晶体管(Thin Film Transistor,TFTs),建立了一种高浓度掺杂态密度模型(High Concentration Doping Density Of States model,HCD-DOS model),并通过数值模拟研究态密度关键参数对器件性能的影响,以此揭示a-IGZO TFTs中制备工艺对导电沟道修复的物理机理.首先,采用结合强度较高的钼/铜双层结构作为栅/源/漏电极,引入BCE方法制备了底栅顶接触(BottomGate Top-Contact,BG-TC)TFTs.其次,建立了适用于BCE技术的a-IGZO TFTs的HCD-DOS模型.随后,基于TCAD(Technology Computer Aided Design)仿真器对态密度关键参数进行数值研究,结果表明,不同态密度参数对a-IGZO TFTs器件转移特性曲线、电学特性以及沟道内部电子浓度分布的影响有所差异.最后,基于HCD-DOS模型探索SiO_(x)钝化层沉积和N_(2)O等离子体处理对器件内部机理的影响.研究发现,N2O等离子体处理对态密度分布和沟道载流子浓度有显著影响,进而导致阈值电压正向漂移.展开更多
文摘The in-flight and deposition properties of three types of WC-17 Co powder with different particle densities during a high-velocity oxygen fuel （HVOF） thermal spray process were investigated. Three types of powder exhibited similar velocity upon impact on the substrate surface. The powder with the lower particle density exhibited a higher temperature upon impingement process, resulting in the generation of a higher flattening ratio. Thus, the coating derived from the powder with the lower particle density possessed superior micro-hardness, porosity and surface roughness. However, the coating with the lowest particle density showed the poorest fracture toughness because of the generation of the largest amount of amorphous phase.
基金financially supported by the National Research Foundation of Korea(NRF-2022R1A2C2010803)。
文摘Pseudo-capacitive negative electrodes remain a major bottleneck in the development of supercapacitor devices with high energy density because the electric double-layer capacitance of the negative electrodes does not match the pseudocapacitance of the corresponding positive electrodes.In the present study,a strategically improved Ni-Co-Mo sulfide is demonstrated to be a promising candidate for high energy density supercapattery devices due to its sustained pseudocapacitive charge storage mechanism.The pseudocapacitive behavior is enhanced when operating under a high current through the addition of a classical Schottky junction next to the electrode-electrolyte interface using atomic layer deposition.The Schottky junction accelerates and decelerates the diffusion of OH-/K+ions during the charging and discharging processes,respectively,to improve the pseudocapacitive behavior.The resulting pseudocapacitive negative electrodes exhibits a specific capacity of 2,114 C g^(-1)at 2 A g^(-1)matches almost that of the positive electrode’s 2,795 C g^(-1)at 3 A g^(-1).As a result,with the equivalent contribution from the positive and negative electrodes,an energy density of 236.1 Wh kg^(-1)is achieved at a power density of 921.9 W kg^(-1)with a total active mass of 15 mg cm-2.This strategy demonstrates the possibility of producing supercapacitors that adapt well to the supercapattery zone of a Ragone plot and that are equal to batteries in terms of energy density,thus,offering a route for further advances in electrochemical energy storage and conversion processes.
基金financially supported by the National Natural Science Foundation of China(No.51373059)the Graphene Powder&Composite Materials Research Center of FujianXiamen Key Laboratory of Polymers and Electronic Materials。
文摘Janus films with asymmetric physical/chemical properties have attracted con siderable attention due to their promising applications in personal thermal management,electronic skin s,sensors,actuators,etc.However,traditional methods for fabricating Janus films conventionally need the assistance of an interface or auxiliary equipment,which are usually complex and time-consuming.Herein,flexible poly(vinyl alcohol)(PVA)/graphene oxide(GO)/h-BN(recorded as PVA/GO/h-BN)Janus films with thermally,optically,and electrically anisotropic properties are fabricated by a simple density deposition self-assem bly method,which just utilizes the density difference between GO and h-BN during water evaporation.Experimental results show that the two sides of the acquired Janus films have obvious asymmetric characteristics.In the original state of the PVA/GO/h-BN Janus films,the thermal conductivity of the GO side(10.06 W·m^(-1)·K^(-1))is generally lower than that of the h-BN side(10.48W·m^(-1)·K^(-1)).But after GO is reduced,the thermal conductivity of the rGO side reaches 12.17 W·m^(-1)·K^(-1),surpassing that of the h-BN side.In addition,the relative reflectance of the h-BN side of Janus film is also significantly higher than that of the rGO side,and the su rface resistance difference between the two sides is about 4 orders of magnitude.The prepared PVA/GO/h-BN Janus films show great application potential in human thermal management,light conversion switches,and electronic skins.This study provides a simple and versatile strategy for fabricating Janus films with multifunctional(such as thermal,optical,and electrical)anisotropies.
文摘目的筛选影响胆固醇调节元件结合蛋白1a(cholesterol regulatory element binding protein,SREBP1a)蛋白稳定性的去泛素化酶,并探索其调控机制。方法通过去泛素化酶库筛选显著影响SREBP1a表达的去泛素化酶,免疫蛋白印记实验和实时荧光定量PCR(qRT-PCR)评估去泛素化酶对SREBP1a以及升脂基因表达的影响;通过红色荧光蛋白标记人源低密度脂蛋白(human Dil-low density lipoprotein,Human Dil-LDL)摄取和油红O染色等实验技术检测细胞摄取低密度脂蛋白(LDL)和脂质沉积情况。结果去泛素化酶库筛选发现泛素特异肽酶37(ubiquitin specific peptidase 37,USP37)可显著增加肝细胞SREBP1a蛋白表达水平,促进胆固醇摄取及脂质沉积。USP37基因敲除可显著降低SREBP1a蛋白表达水平,抑制升脂基因表达及脂质沉积。结论去泛素化酶USP37通过稳定SREBP1a蛋白表达,促进胆固醇摄取及脂质沉积,揭示了SREBP1a翻译后调控的新模式。
文摘针对背沟道刻蚀(Back Channel Etch,BCE)技术的非晶铟镓锌氧化物(a-IGZO)薄膜晶体管(Thin Film Transistor,TFTs),建立了一种高浓度掺杂态密度模型(High Concentration Doping Density Of States model,HCD-DOS model),并通过数值模拟研究态密度关键参数对器件性能的影响,以此揭示a-IGZO TFTs中制备工艺对导电沟道修复的物理机理.首先,采用结合强度较高的钼/铜双层结构作为栅/源/漏电极,引入BCE方法制备了底栅顶接触(BottomGate Top-Contact,BG-TC)TFTs.其次,建立了适用于BCE技术的a-IGZO TFTs的HCD-DOS模型.随后,基于TCAD(Technology Computer Aided Design)仿真器对态密度关键参数进行数值研究,结果表明,不同态密度参数对a-IGZO TFTs器件转移特性曲线、电学特性以及沟道内部电子浓度分布的影响有所差异.最后,基于HCD-DOS模型探索SiO_(x)钝化层沉积和N_(2)O等离子体处理对器件内部机理的影响.研究发现,N2O等离子体处理对态密度分布和沟道载流子浓度有显著影响,进而导致阈值电压正向漂移.
