Enhanced Spin–Orbit Torques in Graphene by Pt Adatoms Decoration

Graphene(Gr)with widely acclaimed characteristics,such as exceptionally long spin diffusion length at room temperature,provides an outstanding platform for spintronics.However,its inherent weak spin–orbit coupling(SOC)has limited its efficiency for generating the spin currents in order to control the magnetization switching process for applications in spintronics memories.Following the theoretical prediction on the enhancement of SOC in Gr by heavy atoms adsorption,here we experimentally observe a sizeable spin–orbit torques(SOTs)in Gr by the decoration of its surface with Pt adatoms in Gr/Pt(t Pt)/Fe Ni trilayers with the optimal damping-like SOT efficiency around 0.55 by 0.6-nm-thick Pt layer adsorption.The value is nearly four times larger than that of the Pt/Fe Ni sample without Gr and nearly twice the value of the Gr/Fe Ni sample without Pt adsorption.The efficiency of the enhanced SOT in Gr by Pt adatoms is also demonstrated by the field-free SOT magnetization switching process with a relatively low critical current density around 5.4 MA/cm^(2)in Gr/Pt/Fe Ni trilayers with the in-plane magnetic anisotropy.These findings pave the way for Gr spintronics applications,offering solutions for future low power consumption memories.

Orbital torque of Cr-induced magnetization switching in perpendicularly magnetized Pt/Co/Pt/Cr heterostructures

The spin–orbit torque via the spin Hall effect of heavy metals has shown promising prospect in driving the magnetization switching in spintronic devices due to the generated spin current from heavy metals.Recently,the 3d-light metals have been predicted the ability to generate orbital current and the associated orbital torques from the orbital Hall effect.However,few experiments have been carried out since it is quite hard to directly detect the orbital current-generated orbital torque.Here,we report an effective method to demonstrate the strong orbital torques in light metal Cr through a conversion process from orbital current to spin current by introducing the Pt interfacial layer in perpendicularly magnetized symmetric Pt/Co/Pt structures.A quite large and monotonically growth of orbital torque efficiency in Pt/Co/Pt/Cr with the increase of the thickness of Cr layer is obtained with the largest effective orbital torque efficiency around 2.6 Oe/(MA·cm^(-2))(1 Oe=79.5775 A·m^(-1)).The ability of orbital torque to drive the magnetization switching is also reported with the critical switching current density down to the order of 106A·cm^(-2).Our findings prove the efficiency for switching the magnetization from light metal Cr layers through the orbital Hall effect.

Practice of Mind Mapping Technology in"Re-flipped Classroom"Teaching Mode:A Case Study of the Course Principles of Residential District Planning

The present study proposed the"re-flipped classroom"teaching mode taking the course Principles of Residential District Planning as an example.Using the Small Private Online Courses(SPOCs)and Massive Open Online Courses(MOOCs)of the iCourse platform,with the aid of the mind mapping technology,the complex content is visualized to the information that can be easily accepted by the brain,to improve the efficiency of thinking problems and apply theories to practical teaching.The results indicate that the teaching mode combined with mind mapping technology has strong appeal,can improve teacher-student interaction,and effectively improve the teaching effects.Finally,it came up with recommendations including attaching importance to the"re-flipped classroom"teaching mode,integrating teaching methods,and using online platform resources.It is concluded that the research of teaching mode has important theoretical and practical significance for ensuring the teaching quality.

生物纳米孔道单分子多肽磷酸化识别与测量的创新综合实验

生物纳米孔道技术是一种具有革命性意义的单分子电化学分析方法,经过近三十年的发展,已经能够实现单分子DNA测序并广泛应用于多肽、蛋白质等单个生物分子的检测研究。本文探讨了将纳米孔道单分子测量方法引入大学实验教学的必要性与重要性,介绍了生物纳米孔道单分子实验的教学意义、目的、内容及其组织实施方式。本实验采用“科教融合”的教学模式,针对具有一定化学、生物化学基础知识并对科研感兴趣的二、三年级本科生,精心设计并不断优化教学方案,将纳米孔道单分子电化学及相关交叉领域的最新研究成果融入课堂教学,拓展学生的科研视野、激发学生的科研兴趣。此外,通过教师引导,鼓励学生大胆提出问题,自主探索,合作完成实验内容,培养学生的学术思维和综合创新能力。

Light at night and lung cancer risk:A worldwide interdisciplinary and time-series study

Background:Light at night(LAN)has become a concern in interdisciplinary research in recent years.This global interdisciplinary study aimed to explore the exposure-lag-response association between LAN exposure and lung cancer incidence.Methods:LAN data were obtained from the Defense Meteorological Satellite Program’s Operational Linescan System.Data of lung cancer incidence,socio-demographic index,and smoking prevalence of populations in 201 countries/territories from 1992 to 2018 were collected from the Global Burden of Disease Study.Spearman correlation tests and population-weighted linear regression analysis were used to evaluate the correlation between LAN exposure and lung cancer incidence.A distributed lag nonlinear model(DLNM)was used to assess the exposure-lag effects of LAN exposure on lung cancer incidence.Results:The Spearman correlation coefficients were 0.286-0.355 and the population-weighted linear regression correlation coefficients were 0.361-0.527.After adjustment for socio-demographic index and smoking preva-lence,the Spearman correlation coefficients were 0.264-0.357 and the population-weighted linear regression correlation coefficients were 0.346-0.497.In the DLNM,the maximum relative risk was 1.04(1.02-1.06)at LAN exposure of 8.6 with a 2.6-year lag time.After adjustment for socio-demographic index and smoking prevalence,the maximum relative risk was 1.05(1.02-1.07)at LAN exposure of 8.6 with a 2.4-year lag time.Conclusion:High LAN exposure was associated with increased lung cancer incidence,and this effect had a specific lag period.Compared with traditional individual-level studies,this group-level study provides a novel paradigm of effective,efficient,and scalable screening for risk factors.

Carbon dots modified nanoflower petals with super enhanced nitrogen electro-reduction efficiency

Nitrogen electro-reduction reaction(NERR)is a promising alternative method for ammonia production to the Haber-Bosch approach due to mild reaction conditions and free harmful by-product emission.A formidable challenge in bringing NERR closer to the practical application is developing an electrocatalyst which can simultaneously improve the Faraday efficiency and reduce the reaction over-potential.Herein,we fabricated a catalyst of nitrogen-doped carbon dots modified copper-phosphate nanoflower petals(Cu Po-NCDs NF)via a self-assembly method.The flower structure endowed the Cu Po-NCDs NF with large specific surface area,and thus enabled more active sites to be exposed.In particular,we demonstrated that the NCDs modified Cu Po petals with flower-like structure can accelerate the interfacial proton-electron transfer,suppressing the competing hydrogen evolution reaction and promoting the desired NERR process.Ultimately,for the CuPo-NCDs NF catalyzed NERR,the FE_(NH_(3))and the reaction potential both were boosted,the resultant energy efficiency of NERR reached a record-breaking value of 56.5%,and the NH_(3)yield rate increased by 7 times compared to NCDs.This study provides a novel catalyst with a new pathway to boost the NERR.

A Cost-Effective Co-precipitation Method for Synthesizing Indium Tin Oxide Nanoparticles without Chlorine Contamination

Indium tin oxide （ITO） nanoparticles with crystallite size of 12.6 nm and specific surface area of 45.7 m 2 ·g-1 were synthesized by co-precipitation method.The indium solution was obtained by dissolving metal indium in HNO3.The tin solution was obtained by dissolving metal tin in HNO3 and followed by stabilizing with citric acid.The free of chlorine ions in the synthesis process brought several advantages：shortening the synthesis time,decreasing the particle agglomeration,decreasing the chlorine content in the ITO nanoparticles and improving the particle sinterability.This is the first time to report the synthesis of ITO nanoparticles free from chlorine contamination without using the expensive metal alkoxides as starting materials.

A sol-gel method to synthesize indium tin oxide nanoparticles

Transparent conductive indium tin oxide （ITO） nanoparticles were synthesized by a novel sol-gel method. Granulated indium and tin were dissolved in HNO3 and partially complexed with citric acid. A sol-gel process was induced when tertiary butyl alcohol was added dropwise to the above solution. ITO nanopartides with an average crystallite size of 18.5 nm and surface area of 32.6 m^2 ]g were obtained after the gel was heat-treated at 700 ℃, The ITO nanoparticles showed good sinterability, the starting sintering temperature decreased sharply to 900 ℃, and the 1400 ℃ sintered pellet had a density of 98.1% of theoretical density （TD）.

Visualization of an Accelerated Electrochemical Reaction under an Enhanced Electric Field

Locally enhanced electric fields produced by high-curvature structures have been reported to boost the charge transport process and improve the relevant catalytic activity.However,no visual evidence has been achieved to support this new electrochemical mechanism.Here,accelerated electrochemiluminescence(ECL)reactions emitting light are visualized for the first time at the heterogeneous interfaces between microbowls and the supporting electrode surface.The simulation result shows that the electric intensity at the interface with a high curvature is 40-fold higher than that at the planar surface.Consequently,local high electric fields concentrate reactive species to the heterogeneous interfaces and efficiently promote the charge transport reactions,which directly leads to the enhancement of ECL emission surrounding the microbowls.Additionally,the potential to induce visual ECL from a ruthenium complex drops to 0.9 V,which further illustrates the promotion of an electrochemical reaction with the aid of an enhanced electric field.This important visualization of electric field boosted electrochemical reactions helps to establish the proposed electron transfer mechanism and provide an alternative strategy to improve electrocatalytic efficiency.