Rational design of asymmetric atomic Ni-P1N3 active sites for promoting electrochemical CO_(2)reduction

The atomic-level interfacial regulation of single metal sites through heteroatom doping can significantly improve the characteristics of the catalyst and obtain surprising activity.Herein,nickel single-site catalysts(SSCs)with dual-coordinated phosphorus and nitrogen atoms were developed and confirmed(denoted as Ni-PxNy,x=1,2 and y=3,2).In CO_(2)reduction reaction(CO_(2)RR),the CO current density on Ni-PxNy was significantly higher than that of Ni-N4 catalyst without phosphorus modification.Besides,Ni-P1N3 performed the highest CO Faradaic efficiency(FECO)of 85.0%–98.0%over a wide potential range of−0.65 to−0.95 V(vs.the reversible hydrogen electrode(RHE)).Experimental and theoretical results revealed that the asymmetric Ni-P1N3 site was beneficial to CO_(2)intermediate adsorption/desorption,thereby accelerating the reaction kinetics and boosting CO_(2)RR activity.This work provides an effective method for preparing well-defined dual-coordinated SSCs to improve catalytic performance,targetting to CO_(2)RR applications.

DEVELOPMENT OF AN AUTOMATIC WEIGHING PLATFORM FOR MONITORING BODYWEIGHT OF BROILER CHICKENS IN COMMERCIAL PRODUCTION

Bodyweight is a key indicator of broiler production as it measures the production efficiency and indicates the health of a flock.Currently,broiler weight(i.e.,bodyweight)is primarily weighed manually,which is timeconsuming and labor-intensive,and tends to create stress in birds.This study aimed to develop an automatic and stress-free weighing platform for monitoring the weight of floor-reared broiler chickens in commercial production.The developed system consists of a weighing platform,a real-time communication terminal,computer software and a smart phone applet userinterface.The system collected weight data of chickens on the weighing platform at intervals of 6 s,followed by filtering of outliers and repeating readings.The performance and stability of this system was systematically evaluated under commercial production conditions.With the adoption of data preprocessing protocol,the average error of the new automatic weighing system was only 10.3 g,with an average accuracy 99.5%with the standard deviation of 2.3%.Further regression analysis showed a strong agreement between estimated weight and the standard weight obtained by the established live-bird sales system.The variance(an indicator of flock uniformity)of broiler weight estimated using automatic weighing platforms was in accordance with the standard weight.The weighing system demonstrated superior stability for different growth stages,rearing seasons,growth rate types(medium-and slow-growing chickens)and sexes.The system is applicable for daily weight monitoring in floor-reared broiler houses to improve feeding management,growth monitoring and finishing day prediction.Its application in commercial farms would improve the sustainability of poultry industry.

新型电荷型纳米盘的可控制备及其与细胞色素P450的结合性能

分别采用氮气吹干法和旋转蒸发法制备由磷脂和膜支架蛋白组成的电荷型纳米盘,用凝胶过滤色谱对其尺寸分级,分析了其性能,考察了其与肝微粒体细胞色素P450的结合能力。结果表明,纳米盘外观澄清透明,微观呈圆盘状,平均直径10nm,在p H 7.4下Zeta电位为-19.86 m V;肝微粒体破碎液与纳米盘能很好结合,CO差示光谱在450 nm出现明显吸收峰,细胞色素P450含量为0.10 nmol/mg,比活比未经纳米盘处理时提高13.0倍,较传统方法提升1.5倍,且操作时间由数日缩短至数小时。电荷型纳米盘在结合膜蛋白细胞色素P450的同时,活性保持良好,在膜蛋白研究领域极具应用潜力。

Interfacial engineering of 3D hollow CoSe_(2)@ultrathin MoSe_(2)core@shell heterostructure for efficient pH-universal hydrogen evolution reaction

Rational design and construction of low-cost and highly efficient electrocatalysts for hydrogen evolution reaction(HER)is meaningful but challenging.Herein,a robust three dimensional(3D)hollow CoSe_(2)@ultrathin MoSe_(2)core@shell heterostructure(CoSe_(2)@MoSe_(2))is proposed as an efficient HER electrocatalyst through interfacial engineering.Benefitting from the abundant heterogeneous interfaces on CoSe_(2)@MoSe_(2),the exposed edge active sites are maximized and the charge transfer at the hetero-interfaces is accelerated,thus facilitating the HER kinetics.It exhibits remarkable performance in pH-universal conditions.Notably,it only needs an overpotential(η10)of 108 mV to reach a current density of 10 mA·cm^(-2)in 1.0 M KOH,outperforming most of the reported transition metal selenides electrocatalysts.Density functional theory(DFT)calculations unveil that the heterointerfaces synergistically optimize the Gibbs free energies of H2O and H^(*)during alkaline HER,accelerating the reaction kinetics.The present work may provide new construction guidance for rational design of high-efficient electrocatalysts.

Rational design of Fe-N-C electrocatalysts for oxygen reduction reaction:From nanoparticles to single atoms

As an alternative energy,hydrogen can be converted into electrical energy via direct electrochemical conversion in fuel cells.One important drawback of full cells is the sluggish oxygen reduction reaction(ORR)promoted by the high-loading of platinum-group-metal(PGM)electrocatalysts.Fe-N-C family has been received extensive attention because of its low cost,long service life and high oxygen reduction reaction activity in recent years.In order to further enhance the ORR activity,the synthesis method,morphology regulation and catalytic mechanism of the active sites in Fe-N-C catalysts are investigated.This paper reviews the research progress of Fe-N-C from nanoparticles to single atoms.The structure-activity relationship and catalytic mechanism of the catalyst are studied and discussed,which provide a guidance for rational design of the catalyst,so as to promote the more reasonable design of Fe-N-C materials.

Palladium-catalyzed 2-pyridylmethyl-directed β-C(sp^3)—H activation and cyclization of aliphatic amides with gem-dibromoolefins:A rapid access to γ-lactams

The direct Pd-catalyzed β-C（sp3）--H activation and cyclization of aliphatic amides bearing a removable 2-pyridylmethyl directing group with gem-dibromoolefins is described for the first time to construct a variety of γ-lactams, The resulting products with Z- and E-configurations can be easily separated and purified after the reaction, demonstrating the effectiveness and applicability of the method herein developed.