The development of active yet stable catalysts for oxygen reduction reaction(ORR)is still a major issue for the extensive permeation of fuel cells into everyday technology.While nanostructured Pt catalysts are to date...The development of active yet stable catalysts for oxygen reduction reaction(ORR)is still a major issue for the extensive permeation of fuel cells into everyday technology.While nanostructured Pt catalysts are to date the best available systems in terms of activity,the same is not true for stability,particularly under operating conditions.In this work,Pt_(Х)Y alloy nanoparticles are proposed as active and durable electrocatalysts for ORR.Pt_(Х)Y nanoalloys are synthesized and further optimized by laser ablation in liquid followed by laser fragmentation in liquid.The novel integrated laser-assisted methodology succeeded in producing Pt_(Х)Y nanoparticles with the ideal size(<10 nm)of commercial Pt catalysts,yet resulting remarkably more active with E_(1/2)=0.943 V vs.RHE,specific activity=1095μA cm^(-2) and mass activity>1000 A g^(-1).At the same time,the nanoalloys are embedded in a fine Pt oxide matrix,which allows a greater stability of the catalyst than the commercial Pt reference,as directly verified on a gas diffusion electrode.展开更多
翻译了欧洲标准"EN 14569-2004 Foodstuffs-Microbiological screening for irradiated food using LAL/GNB procedures"。该方法已成功通过实验室验证,通常适用于新鲜的整禽或胸脯、腿、翅膀等器官以及去皮或未去皮的冷冻或...翻译了欧洲标准"EN 14569-2004 Foodstuffs-Microbiological screening for irradiated food using LAL/GNB procedures"。该方法已成功通过实验室验证,通常适用于新鲜的整禽或胸脯、腿、翅膀等器官以及去皮或未去皮的冷冻或冰冻畜体的鉴别。该方法还可以提供待辐照样品微生物学质量的情况,但只能说明样品可能经过电离辐射。展开更多
链霉菌可产生许多具有重要应用价值的次级代谢产物，如抗生素、免疫调节剂、抗肿瘤药物等，它们已经广泛应用于临床医药中。次级代谢产物的生物合成受到转录因子的调控，转录因子通过控制结构基因的转录激活或阻遏解除，决定了表达方式...链霉菌可产生许多具有重要应用价值的次级代谢产物，如抗生素、免疫调节剂、抗肿瘤药物等，它们已经广泛应用于临床医药中。次级代谢产物的生物合成受到转录因子的调控，转录因子通过控制结构基因的转录激活或阻遏解除，决定了表达方式和程度。LuxR家族大ATP结合调控因子（large ATP-binding regulators of the LuxR family, LAL）是一类新的次级代谢途径转录因子，由900～1000个氨基酸残基组成，它的N-端具有Walker A和Walker B模体的ATP／GTP结构域，C．端具有保守的LuxR家族螺旋一转角．螺旋模体的DNA结合域。已在40余种次级代谢产物生物合成基因簇中发现LAL，本文对LAL途径特异性转录调控的研究进展进行综述。展开更多
基金the P-DISC Grant PROMETEO(project number:P-DiSC#03NExuS_BIRD2021-UNIPD)DYNAMO(project number:P-P-DiSC#01BIRD2020-UNIPD)the financial support of the Fellowship in Applied Electrochemistry 2020。
文摘The development of active yet stable catalysts for oxygen reduction reaction(ORR)is still a major issue for the extensive permeation of fuel cells into everyday technology.While nanostructured Pt catalysts are to date the best available systems in terms of activity,the same is not true for stability,particularly under operating conditions.In this work,Pt_(Х)Y alloy nanoparticles are proposed as active and durable electrocatalysts for ORR.Pt_(Х)Y nanoalloys are synthesized and further optimized by laser ablation in liquid followed by laser fragmentation in liquid.The novel integrated laser-assisted methodology succeeded in producing Pt_(Х)Y nanoparticles with the ideal size(<10 nm)of commercial Pt catalysts,yet resulting remarkably more active with E_(1/2)=0.943 V vs.RHE,specific activity=1095μA cm^(-2) and mass activity>1000 A g^(-1).At the same time,the nanoalloys are embedded in a fine Pt oxide matrix,which allows a greater stability of the catalyst than the commercial Pt reference,as directly verified on a gas diffusion electrode.
文摘翻译了欧洲标准"EN 14569-2004 Foodstuffs-Microbiological screening for irradiated food using LAL/GNB procedures"。该方法已成功通过实验室验证,通常适用于新鲜的整禽或胸脯、腿、翅膀等器官以及去皮或未去皮的冷冻或冰冻畜体的鉴别。该方法还可以提供待辐照样品微生物学质量的情况,但只能说明样品可能经过电离辐射。
文摘链霉菌可产生许多具有重要应用价值的次级代谢产物，如抗生素、免疫调节剂、抗肿瘤药物等，它们已经广泛应用于临床医药中。次级代谢产物的生物合成受到转录因子的调控，转录因子通过控制结构基因的转录激活或阻遏解除，决定了表达方式和程度。LuxR家族大ATP结合调控因子（large ATP-binding regulators of the LuxR family, LAL）是一类新的次级代谢途径转录因子，由900～1000个氨基酸残基组成，它的N-端具有Walker A和Walker B模体的ATP／GTP结构域，C．端具有保守的LuxR家族螺旋一转角．螺旋模体的DNA结合域。已在40余种次级代谢产物生物合成基因簇中发现LAL，本文对LAL途径特异性转录调控的研究进展进行综述。
