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Enhanced nitrogen electroreduction performance by the reorganization of local coordination environment of supported single atom on N(O)-dual-doped graphene

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Nano Research 2023年第7期16卷 9099-9106页

作者： Zhiqiang Bai Wenhua Zhang yufang liu School of Physics Henan Normal UniversityXinxiang 453007China School of Cable Engineering Henan Institute of TechnologyXinxiang 453000China Hefei National Research Center for Physical Sciences at the Microscale CAS Key Laboratory of Materials for Energy Conversion and Synergetic Innovation Centre of Quantum Information&Quantum PhysicsUniversity of Science and Technology of ChinaHefei 230026China

Developing stable and efficient catalysts for the electroreduction of nitrogen remains a huge challenge and single atom catalysts(SACs)are expected to achieve relatively high ammonia selectivity at low applied *** on density functional theory calculations,the potential application of 27 single transition metal(TM=Sc-Zn,Y-Ag,Hf-Au)atoms supported by N(O)-dualdoped graphene(TM-O_(2)N_(2)/G)for the electroreduction of nitrogen is intensively *** low nitrogen coverage,W(Mo,Nb,Ta)-O_(2)N_(2)/G are predicted to yield low ammonia selectivity(<13%)at limiting-potential of-0.58,-0.53,-0.56,and-0.76 V starting from adsorbed nitrogen with side-on mode,*** the increasing N_(2)coverage,the TM-O_(2)N_(2)/G is reconstructed as TM-(N_(2))2N_(2)/*** electroreduction of nitrogen proceeds from end-on adsorbed nitrogen molecule with high ammonia selectivity,and the limiting-potentials are theoretically predicted as-0.20,-0.40,-0.29,and-0.21 V on W(Mo,Nb,Ta)-(N_(2))2N_(2)/G,*** is suggested that utilizing the reorganization of local coordination environments of SACs by high coverage of reactant molecules under reaction condition can not only enhance the activity at lower limiting-potential but also improve the ammonia selectivity.

关键词： nitrogen reduction reaction single atom catalysis local structure reorganization doped graphene electroreduction

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Combined Transmission Interference Spectrum of No Core Fiber and BP Neural Network for Concentration Sensing Research

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Journal of Beijing Institute of Technology 2017年第2期26卷 267-275页

作者： Fang Wang Heng Lu Yunpeng Li yufang liu College of Electonic and Electrical Engineering Henan Normal University Xinxiang Henan 453007 China Henan Engineering Laboratory of Optoelectronic Technology and Advanced Manufacturing Xinxiang Henan 453007 China

To investigate wavelength response of the no core fiber（NCF）interference spectrum to concentration,a three-layer back propagation（BP）neural network model was established to optimize the concentration sensing *** this method,the measured wavelength and the corresponding concentration were trained by a BP neural network,so that the accuracy of the measurement system was *** wavelength was used as the training set and got into the input layer of the three layer BP network model which is used as the input value of the network,and the corresponding actual concentration value was used as the output value of the network,and the optimal network structure was *** paper discovers a preferable correlation between the predicted value and the actual value,where the former is approximately equal to the *** correlation coefficients of the measured and predicted values for a sucrose concentration were 1.000 89 and 1.003 94;similarly,correlations of0.999 51 and 1.018 8 for a glucose concentration were *** results demonstrate that the BP neural network can improve the prediction accuracy of the nonlinear relationship between the interference spectral data and the concentration in NCF sensing systems.

关键词： no core fiber dislocation optical fiber BP neural network concentration detection interference spectrum

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Health Status of Left-Behind Children and Parenting Behaviors of Caregivers in Poor Rural Areas-6 Provinces,China,2018

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China CDC weekly 2021年第3期3卷 54-57页

作者： Feifei Jin Zhengkui liu yufang liu Chen Yao Yulan Cheng Peking University First Hospital BeijingChina Institute of Psychology Chinese Academy of SciencesBeijingChina Chinese Center for Health Education BeijingChina Peking University Clinical Research Institute BeijingChina

What is already known about this topic?China has a significant population of left-behind children,and their health and living environments remain a major public health *** under 6 years old are especially vulnerable to poor health knowledge and behaviors of their *** is added by this report?The prevalence of stunting,being underweight,and often sick were 13%,3.4%,and 5%,*** 53.9%of left-behind children could eat meat often,and 59.5%could control their intake of sugary *** proportions of children who had a safe home environment,a safe play environment,and no family violence were 22.5%,75.3%,and 45.9%,*** percentages of caregivers who ensured that they rarely left their children alone and were always in their sight are 76.1%and 92.4%,*** are the implications for public health practice?The implementation of early home visits is necessary to improve the physical health and safety of the living environment of left-behind *** health workers should pay attention to improving the health knowledge and behaviors of caregivers.

关键词： Rural give environments

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Ultra-high current gain tunneling hot-electron transfer amplifier based on vertical van der Waals heterojunctions

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Nano Research 2020年第8期13卷 2085-2090页

作者： Xu Zhao Peng Chen Xingqiang liu Guoli Li Xuming Zou Yuan liu Qilong Wu yufang liu Woo Jong Yu Lei Liao Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education&Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices School of Physics and ElectronicsChangsha410082China Henan Normal University School of PhysicsXinxiang453007China Department of Electronic and Electrical Engineering Sungkyunkwan UniversitySuwon440-746Republic of Korea

Due to the backscattered parasitic current from the barriers,the current gain of the widely used amplifier is far from *** this work,we demonstrate a vertical Au/Al2O3/BP/MoS2 tunneling hot-electron transfer amplifier with a hot-electron emitter-base junction and a p-n junction as the base-collector *** monoenergetic electrons traverse through the ultrathin Al2O3 dielectric via tunneling,which are accelerated and shifted to the collector *** devices exhibit a high current on-off ratio of>105 and a high current density(JC)of∼1,000 A/cm2 at the same ***,this work demonstrates a common-emitter current gain(β)value of 1,384 with a nanowatt power consumption at room temperature,which is a record high value among the all 2D based hot-electron ***,the temperature dependent performance is investigated,and theβvalue of 1,613 is obtained at 150 ***,this work presents the potential of 2D based transistors for high-performance applications.

关键词： bipolar junction transistor hot electron van der Waals heterostructure current gain

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Carbon-doping-induced negative differential resistance in armchair phosphorene nanoribbons

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Journal of Semiconductors 2017年第3期38卷 82-87页

作者： Caixia Guo Congxin Xia Tianxing Wang yufang liu College of Physics and Materials Science Henan Normal University Xinxiang 453007 China

By using a combined method of density functional theory and non-equilibrium Green＇s function formalism,we investigate the electronic transport properties of carbon-doped armchair phosphorene nanoribbons（APNRs）.The results show that C atom doping can strongly affect the electronic transport properties of the APNR and change it from semiconductor to ***,obvious negative differential resistance（NDR） behaviors are obtained by tuning the doping position and *** particular,with reducing doping concentration,NDR peak position can enter into m V bias *** results provide a theoretical support to design the related nanodevice by tuning the doping position and concentration in the APNRs.

关键词： C atom doping armchair phosphorene nanoribbon negative differential resistance behavior

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Isotope effect and Coriolis coupling effect forthe Li + H(D)Cl → LiCl + H(D) reaction

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Chinese Physics B 2019年第5期28卷 90-94页

作者： Hongsheng Zhai Guanglei Liang Junxia Ding yufang liu College of Physics and Materials Science Henan Normal University Spectral Measurement and Application of Infrared Material Key Laboratory of Henan Province Academy of Physics and Materials Science Henan Normal University State Key Laboratory of Molecular Reaction Dynamics Dalian Institute of Chemical Physics Chinese Academy of Sciences

A time-dependent quantum wave packet method is used to investigate the dynamics of the Li + H(D)Cl reaction based on a new potential energy surface(J. Chem. Phys. 146 164305(2017)). The reaction probabilities of the Coriolis coupled(CC) and centrifugal sudden(CS) calculations, the integral cross sections, the reaction rate constants are obtained. The rate constants of the Li + HCl reaction are within the error bounds at low temperature. A comparison of the CC and CS results reveals that the Coriolis coupling plays an important role in the Li + H(D)Cl reaction. The CC cross sections are larger than the CS results within the entire energy range, demonstrating that the Coriolis coupling effect can more effectively promote the Li + DCl reaction than the Li + HCl reaction. It is found that the isotope effect has a great influence on the title reaction.

关键词： isotope effect Coriolis coupling rate constant quantum wave packet

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Spatial distribution of soil salinization under the influence of human activities in arid areas,China

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Journal of Arid Land 2024年第10期16卷 1344-1364页

作者： liu yufang YANG Qingwen PEI Xiangjun LI Jingji WANG Shuangcheng HUANG Zhenfu HAN Wei ZHENG Tianliang College of Ecology and Environment Chengdu University of TechnologyChengdu 610059China Tianfu Yongxing Laboratory Chengdu 610213China Hydrogeological and Engineering Geological Team of Xinjiang Bureau of Geo-Exploration&Mineral Development Changji 831100China

The Hotan Prefecture of Xinjiang Uygur Autonomous Region,China belongs to arid desert climate,with significant soil salinization *** study selected six rivers in Hotan Prefecture(Pishan,Qaraqash,Yurungqash,Celle,Kriya,and Niya rivers)to explore the spatial distribution of soil salinization in this area and its underlying *** was conducted along each river's watershed,from the Gobi in the upper reaches,through the anthropogenic impact area in the middle reaches,to the desert area in the lower *** physical-chemical indicators,including total soluble salts,pH,K+,Na+,Ca2+,Mg2+,SO42-,Cl-,CO32-,HCO3-,organic matter,available nitrogen,available phosphorus,and available potassium,were tested,along with the total dissolved solids of surface water and *** results revealed that the soil water and nutrient contents in anthropogenic impact area were higher than those in Gobi and desert areas,while the pH and total soluble salts were lower than those in Gobi and desert *** ions in the soil of the study area were primarily Cl-,SO42-,K+,and Na+,and the ion concentration of soil salt were positively correlated with surface water and ***,the study area exhibited low soil water content,low clay content,infertile soil,and high soil salinization,dominated by weak to moderate chloride-sulfate *** with Gobi and desert areas,the soil in anthropogenic impact area had higher soil water content,lower pH,lower soluble salts,and higher nutrients,indicating that human farming activities help mitigate *** findings have practical implications for guiding the scientific prevention and control of soil salinization in the arid areas and for promoting sustainable agricultural development.

关键词： soil salinization human activities spatial distribution Hotan Prefecture soil soluble salt soil nutrient

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All-metallic metasurfaces towards high-performance magneto-plasmonic sensing devices

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Photonics Research 2020年第11期8卷 1742-1748页

作者： Lixia Li Xueyang Zong yufang liu Henan Key Laboratory of Infrared Materials&Spectrum Measures and Applications School of PhysicsHenan Normal UniversityXinxiang 453007China

Magneto-plasmonic sensors based on surface plasmon resonance have been studied considerably in recent years,as they feature high sensitivity and ultrahigh ***,the majority of such investigations focus on prism-based sandwich architectures that not only impede the miniaturization of devices but also have a weak transverse magneto-optical Kerr effect(TMOKE)in ***,we theoretically demonstrate a magneto-plasmonic sensor composed of Au/Co bilayer nanodisk arrays on top of optically thick metallic films,which supports a narrow surface plasmon resonance(SPR)with a bandwidth of 7 nm and allows for refractive index sensitivities as high as 717 nm/*** to the high-quality SPR mode,a Fano-like TMOKE spectrum with a subnanometer bandwidth can be achieved in the proposed structure,thereby giving rise to ultrahigh sensing of merit values as large as 7000 in ***,we demonstrate a large TMOKE magnitude that exceeds *** value is 1 order of magnitude larger than that of magneto-plasmonic sensors *** also demonstrate that the behavior of TMOKE spectra can be controlled by tuning the geometrical parameters of the device including the diameter and thickness of nanodisk *** work provides a promising route for designing magneto-plasmonic sensors based on metasurfaces or metamaterials.

关键词： metallic magneto thereby

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Dynamic changes of genomic methylation profiles at different growth stages in Chinese Tan sheep

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Journal of Animal Science and Biotechnology 2022年第1期13卷 82-93页

作者： yufang liu Qiao Xu Xiaolong Kang Kejun Wang Jve Wang Dengzhen Feng Ying Bai Meiying Fang Department of Animal Genetics and Breeding National Engineering Laboratory for Animal BreedingMOA Laboratory of Animal Genetics and BreedingCollege of Animal Science and TechnologyChina Agricultural UniversityNo.2 Yuanmingyuan West RdBeijing 100193People’s Republic of China College of Life Sciences and Food Engineering Hebei University of EngineeringHandan 056021People’s Republic of China Biotechnology Institute Nanchang Normal UniversityNanchang 330029People’s Republic of China College of Agriculture Ningxia UniversityYinchuan 750021People’s Republic of China College of Animal Science and Veterinary Medicine Henan Agricultural UniversityZhengzhou 450002People’s Republic of China Beijing Key Laboratory for Animal Genetic Improvement Beijing 100193People’s Republic of China

Background:Tan sheep,an important local sheep breed in China,is famous for their fur ***-month-old Tan sheep have white,curly hair with beautiful flower spikes,commonly known as“nine bends”,which has high economic ***,the“nine bends”characteristic gradually disappears with age;consequently,the economic value of the Tan sheep ***-related changes in DNA methylation have been reported and may be responsible for age-induced changes in gene *** now,no genome-wide surveys have been conducted to identify potential DNA methylation sites involved in different sheep growth *** this study we investigated the dynamic changes of genome-wide DNA methylation profiles in Tan sheep using DNA from skin and deep whole-genome bisulfite sequencing,and compared the DNA methylation levels at three different growth stages:1,24,and 48 months old(mon1,mon24,and mon48,respectively).Results:In this study,11 skin samples from three growth stages(four for mon1,four for mon24,and three for mon48)were used for DNA methylation analysis and gene expression *** were 52,288 and 236 differentially methylated genes(DMGs)identified between mon1 and mon24,mon1 and mon48,and mon24 and mon48,*** the differentially methylated regions,1.11%,7.61%,and 7.65% were in the promoter in mon1 ***24,mon24 ***48,and mon1 ***48,*** were enriched in the MAPK and WNT signaling pathways,which are related to age growth and hair follicle morphogenesis *** were 51 DMGs associated with age growth and curly fleece *** DMGs between mon1 and mon48(KRT71,CD44,ROR2 and ZDHHC13)were further validated by bisulfite ***:This study revealed dynamic changes in the genomic methylation profiles of mon1,mon24,and mon48 sheep,and the percentages of methylated cytosines were 3.38%,2.85% and 4.17%,*** the DMGs,KRT71 and CD44 were highly methylated in mon1,and ROR2 and ZDHHC13 were highly methylated

关键词： Chinese tan sheep Different growth stages DNA methylation Whole genome bisulfite sequencing

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Tuning coherent phonon dynamics in two-dimensional phenylethylammonium lead bromide perovskites

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Nano Research 2023年第2期16卷 3408-3414页

作者： Minghuan Cui Chaochao Qin Zhongpo Zhou Yuanzhi Jiang Shichen Zhang Zeye Yuan Mingjian Yuan Kun Yu Yuhai Jiang yufang liu Henan Key Laboratory of Infrared Materials&Spectrum Measures and Applications School of PhysicsHenan Normal UniversityXinxiang 453007China Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education) College of ChemistryNankai UniversityTianjin 300071China Center for Transformative Science and School of Physical Science and Technology ShanghaiTech UniversityShanghai 201210China

Organic-inorganic layered perovskites are two-dimensional quantum well layers in which the layers of lead halide octahedra are stacked between the organic cation *** packing geometry of the soft organic molecules and the stiff ionic crystals induce structural deformation of the inorganic octahedra,generating complex lattice ***,the dielectric confinement and ionic sublattice lead to strong coupling between the photogenerated excitons and the phonons from the polar lattice which intensively affects the properties for device *** anharmonicity and dynamic disorder from the organic cations participate in the relaxation dynamics coupled with ***,a detailed understanding of this underlying mechanism remains *** work investigates the electron–optical phonon coupling dynamics by employing ultrafast pump-probe transient absorption *** activated different optical phonon modes are observed via systematic studies of(PEA)_(2)PbBr_(4) perovskite films on the ultrafast lattice vibrational *** experimental results indicate that solvent engineering has a significant influence on lattice vibrational modes and coherent phonon *** work provides fresh insights into electron-optical phonon coupling for emergent optoelectronics development based on layered perovskites.

关键词： two-dimensional perovskites electron–optical phonon coupling ultrafast dynamics transient absorption

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