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Facile Synthesis of Bimetallic Au@Pd Nanoparticles with Core-shell Structures on Graphene Nanosheets

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Journal of Materials Science & Technology 2014年第11期30卷 1071-1077页

作者： nanting li Shaochun Tang Xiangkang Meng Institute of Materials Engineering National Laboratory of Solid State MicrostructuresCollege of Engineering and Applied SciencesNanjing University

In this paper, we report a simple one-step thermal reducing method for synthesis of bimetallic Au@Pd nanoparticles with core-shell structures on the graphene surface. This new type of Au@Pd-G composites is characterized by transmission electron microscopy, high resolution transmission electron microscopy, X-ray photoelectron spectroscopy and X-ray diffraction. It is found that Au@Pd nanoparticles with an average diameter of 11 nm are well dispersed on the graphene surface, and the Au core quantity as well as the Pd shell thickness can be quantitatively controlled by loading different amounts of metallic precursors, and the involved core-shell structure formation mechanism is also discussed. The ternary Pt/Au@Pd-G composites can also be synthetized by the subsequent Pt doping. The catalytic performance of Au@Pd-G composites toward methanol electro-oxidation in acidic media is investigated. The results show that Au@Pd-G composites exhibit higher catalytic activity, better stability and stronger tolerance to CO poisoning than Pd-G and Au-G counterparts.

关键词： Composite materials Nanoparticles Electric properties Materials synthesis Mierostructure

Reduced Graphene Oxide Supported Bimetallic CobaltPalladium Nanoparticles with High Catalytic Activity towards Formic Acid Electro-oxidation

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Journal of Materials Science & Technology 2015年第1期31卷 30-36页

作者： nanting li Shaochun Tang Xiangkang Meng Institute of Materials Engineering National Laboratory of Solid State Microstructures and College of Engineering and Applied SciencesNanjing University

In this work,we report the growth of uniformly dispersed bimetallic cobalt-palladium nanoparticles(NPs) on reduced graphene oxide(RGO) nanosheets to prepare CoPd-RGO composites via a two-step procedure,where firstly formed Co NPs are used as seeds for the subsequent growth of *** generation of Co NPs on RGO is performed by an in-situ reduction reaction with the reducer ethylene glycol under oil bath at180 ℃.According to composition,size and microstructure analyses,NPs in the resulting CoPd-RGO have an average particle size of 5 nm,and Pd is added to one side of Co NPs,thus forming Co-Pd bimetallic *** involved formation mechanism is *** composite is used as an electro-catalyst for the formic acid oxidation in alkaline electrolyte,and the catalytic performance is investigated by cyclic voltammetry and chronopotentiometry *** results show that the composite has the highest electrocatalytic activity,the best electrochemical stability and the highest resistance to CO poisoning than those of the monometallic composite and commercial Pd black at the same *** is due not only to the small size of NPs with Co-Pd bimetallic interfaces providing more active atoms accessible for reactants,but also to the electric synergistic effect between metals and graphene.

关键词： Composite materials Nanoparticles Electric propert

Preparation of Pt–GO composites with high-number-density Pt nanoparticles dispersed uniformly on GO nanosheets

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Progress in Natural Science:Materials International 2016年第2期26卷 139-144页

Pt–GO composites with high-number-density Pt nanoparticles dispersed uniformly on GO nanosheets were prepared using ethylene glycol as reducer at 180 °C. The nanoparticles had an average size of 12 nm with corners and edges on their surfaces. The composites had electrochemically active surface area of 31.7 m2g-1with a ratio（I_f/Ir=0.96） of the forward anodic peak current（I_f） to the reverse anodic peak current（Ir） in cyclic voltammetry curves, which is much higher than those of the reported Pt nanodendrites/reduced graphene oxide composites.

关键词： Graphene Platinum nanoparticles Formic acid electro-oxidation

Microstructure and damping properties of LPSO phase dominant Mg-Ni-Y and Mg-Zn-Ni-Y alloys

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Journal of Magnesium and Alloys 2024年第3期12卷 1131-1153页

作者： Ruopeng Lu Kai Jiao nanting li Hua Hou Jingfeng Wang Yuhong Zhao College of Materials Science and Engineering North University of ChinaTaiyuan 030051China College of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan 030024China National Engineering Research Center for Magnesium Alloys Chongqing UniversityChongqing 400044China College of Materials Science and Engineering Chongqing UniversityChongqing 400044China

This work studied the microstructure,mechanical properties and damping properties of Mg_(95.34)Ni_(2)Y_(2.66) and Mg_(95.34)Zn_(1)Ni_(1)Y_(2.66)alloys *** difference in the evolution of the long-period stacked ordered(LPSO)phase in the two alloys during heat treatment was the *** morphology of the as-cast Mg_(95.34)Ni_(2)Y_(2.66)presented a disordered *** heat treatment at 773 K for 2 hours,the eutectic phase was integrated into the matrix,and the LPSO phase maintained the 18R *** Zn partially replaced Ni,the crystal grains became rounded in the cast alloy,and lamellar LPSO phases and more solid solution atoms were contained in the matrix after heat treatment of the Mg_(95.34)Zn_(1)Ni_(1)Y_(2.66)*** Zn and the heat treatment had a significant effect on *** dislocation internal friction peaks and grain boundary internal friction peaks were found after temperature-dependent damping of the Mg_(95.34)Ni_(2)Y_(2.66)and Mg_(95.34)Zn_(1)Ni_(1)Y_(2.66)*** heat treatment,the dislocation peak was significantly increased,especially in the alloy Mg_(95.34)Ni_(2)Y_(2).*** annealed Mg_(95.34)Ni_(2)Y_(2.66)alloy with a rod-shaped LPSO phase exhibited a good damping performance of 0.14 atε=10^(−3),which was due to the difference between the second phase and solid solution atom *** factors also affected the dynamic modulus of the *** results of this study will help in further development of high-damping magnesium alloys.

关键词： Mg-Ni-Y alloys Mg-Zn-Ni-Y alloys LPSO phase Heat treatment Microstructure Damping properties.

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消费升级背景下贵州旅游供应链优化研究

物流科技 2022年第3期45卷 140-142页

作者：李南婷贵州大学管理学院贵州贵阳550025

旅游业是贵州支柱产业,随着时代发展与人们对物质、精神生活要求的提高,消费升级,现阶段贵州旅游业无法满足当前旅游者个性化、体验式的消费需求,贵州旅游业有效供应不足、不匹配、结构发展不均衡等问题阻碍了贵州旅游市场的整体发展。... 详细信息

旅游业是贵州支柱产业,随着时代发展与人们对物质、精神生活要求的提高,消费升级,现阶段贵州旅游业无法满足当前旅游者个性化、体验式的消费需求,贵州旅游业有效供应不足、不匹配、结构发展不均衡等问题阻碍了贵州旅游市场的整体发展。由消费升级引起的供给侧改革,是贵州旅游业发展的新契机,如何根据市场消费需求不断升级的现状推出与其相匹配的旅游服务供应链是当前贵州旅游业发展的重点课题。文章结合消费者升级背景,以消费者需求视角,从景点信息查询、旅游服务预订、旅游综合感知三个阶段分析了贵州旅游供应链现存问题,为如何进一步推动贵州旅游供应链优化升级提出建议。

关键词：消费升级贵州旅游业供应链优化

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基于PSR样本分类的自适应去污算法

计算机工程与应用 2022年第6期58卷 200-207页

作者：史思琦马彦军李南廷郑莉平西安理工大学自动化与信息工程学院西安710048 西安理工大学电气工程学院西安710048 陕西省复杂系统控制与智能信息处理重点实验室西安710048

针对相关滤波跟踪算法中训练样本污染容易导致模型漂移和目标丢失等问题,提出基于峰值旁瓣比样本分类的自适应去污算法,建立了样本污染特征、滤波器响应图和跟踪结果之间的内在联系,研究了样本分类机制和参数动态更新策略。通过样本分... 详细信息

针对相关滤波跟踪算法中训练样本污染容易导致模型漂移和目标丢失等问题,提出基于峰值旁瓣比样本分类的自适应去污算法,建立了样本污染特征、滤波器响应图和跟踪结果之间的内在联系,研究了样本分类机制和参数动态更新策略。通过样本分类阈值将训练样本划分为反映不同污染程度的样本集,并分别训练出对应各类样本集的滤波器;根据峰值旁瓣比动态更新特定样本集的样本权值及其滤波器参数;对各类样本集的相关滤波器进行加权融合实现目标跟踪。在OTB-50和TC-128数据集的测试结果表明:该方法有效抑制了严重污染样本的影响并提高了复杂场景目标跟踪的准确性和鲁棒性。

关键词：目标跟踪相关滤波自适应去污样本分类

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浴缸水温控制的最优注水方案研究

电子测试 2018年第19期29卷 5-8,11页

作者：李若韬张文瑜李南廷肖绪洋重庆文理学院重庆402160

浴缸是人们日常生活中必不可少的一种生活用具。基于流体流动和热量传递的原理,本文研究了水经热水器加热后再输送至浴缸过程中水温的控制模型以及浴缸热水温度分布状态。理论推导得到了浴缸中水的传导传热和对流传热的传递方程,通过联... 详细信息

浴缸是人们日常生活中必不可少的一种生活用具。基于流体流动和热量传递的原理,本文研究了水经热水器加热后再输送至浴缸过程中水温的控制模型以及浴缸热水温度分布状态。理论推导得到了浴缸中水的传导传热和对流传热的传递方程,通过联系人体皮肤与外界环境的热量交换方程,获得单位时间内应注入浴缸的热水量体积为:Q_V=∫Ω(T)(t/T+U·▽t-λ/cp·▽~2t+ηA_f/cpV·(T_(water)-T_(outside)-XA_P/cpV·(T_(average)-T_(outside)))dV/T_(hotwater)-T_(water)。给定边界条件,以C语言程序得到近似数值解并利用Matlab绘制浴缸内水的温度场分布图,最后将三维温度场简化为一维温度场,求得热水流量数值8.227×10^(-3)m^3/s,符合实际情况。

关键词：浴缸热传导方程 Matlab 高斯-赛德尔迭代法傅里叶导数

典型喀斯特地区土壤重金属累积特征及环境风险评价

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农业资源与环境学报 2021年第5期38卷 797-809页

作者：刘南婷刘鸿雁吴攀罗广飞李学先贵州大学农学院贵阳550025 贵州大学资源与环境工程学院贵阳550025 喀斯特地质资源与环境教育部重点实验室贵阳550025

基于225个样点分析了贵州省不同地区(自然背景区、农业种植区和矿区)表层土壤重金属As、Cd、Cr、Cu、Hg、Pb、Zn的含量、分布及累积特征,采用地积累指数(Igeo)对土壤重金属污染水平进行评价,并根据潜在生态风险指数(RI)及人体健康风险... 详细信息

基于225个样点分析了贵州省不同地区(自然背景区、农业种植区和矿区)表层土壤重金属As、Cd、Cr、Cu、Hg、Pb、Zn的含量、分布及累积特征,采用地积累指数(Igeo)对土壤重金属污染水平进行评价,并根据潜在生态风险指数(RI)及人体健康风险评估模型评估了不同分区土壤重金属暴露的生态风险和人体健康风险水平。结果表明:贵州省不同分区表层土壤中重金属含量差异较大,与贵州省土壤背景值相比,农业种植区土壤Hg、Zn、Cd和As累积特征明显;矿区土壤Hg、Zn、Cd、Pb和As累积特征较显著,平均含量分别是贵州省土壤背景值的52.55、23.22、16.32、14.48倍和4.85倍。Igeo值显示自然背景区土壤重金属处于无污染水平,而农业种植区各重金属主要处于无污染或无-中污染水平,矿区污染程度较突出,重金属Hg、Zn、Cd、Pb达到中污染水平,特别是在黔西北和铜仁等矿产资源分布区。综合生态风险评价结果表明,矿区土壤中重金属生态风险水平远高于农业种植区和自然背景区,矿产资源集中分布区土壤重金属生态风险较高,部分样点达到高生态风险水平。单一重金属潜在生态风险评价结果显示,农业种植区和矿区土壤中Hg、Cd、Pb和As为主要风险因子,Cr和Cu处于低风险状态。人体健康风险评估结果显示,矿区的人体健康风险高于农业种植区,农业种植区和矿区土壤对成人的非致癌风险在可接受范围内,但致癌风险不可忽视,对儿童的非致癌风险与致癌风险均高于成人。

关键词：土壤重金属累积生态风险健康风险风险评价喀斯特地区

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福建省海水贝藻类养殖碳汇能力及其影响机制

环境科学学报 2024年第3期44卷 409-418页

作者：马淑媛张晨段羽歆李晨欣张巧文龚梓彤卜楠婷黄子晗福建师范大学福建省亚热带资源与环境重点实验室福州350117 福建师范大学地理科学学院福州350117 福建师范大学地理研究所福州350117

研究聚焦于市域、县域等微观尺度,系统探究了福建省海水贝藻类养殖碳汇能力及其空间特征,并判识主要影响因子及其交互关系.结果表明:福建省具有丰富的海水贝藻类养殖碳汇,其规模高达107万t,但大部分地区碳汇规模与碳汇效率不成正比.通... 详细信息

研究聚焦于市域、县域等微观尺度,系统探究了福建省海水贝藻类养殖碳汇能力及其空间特征,并判识主要影响因子及其交互关系.结果表明:福建省具有丰富的海水贝藻类养殖碳汇,其规模高达107万t,但大部分地区碳汇规模与碳汇效率不成正比.通过进一步养殖结构优化,到2025年福建省海水贝藻类养殖将拥有约270万t碳汇潜力.此外,福建省海水贝藻类养殖碳汇规模在空间上呈明显的集聚型,高-高集聚主要分布在宁德与福州交界处、莆田中段与漳州中段,低-低集聚分布在三都澳、湄洲岛、泉州和诏安湾地区.总体来看,规模效应是福建省当前贝藻类养殖碳汇量变化的主导因子,人均GDP、废水排放总量的单因子影响力相对较低,但与养殖结构、养殖密度交互作用后呈非线性增强趋势.

关键词：海水贝藻类养殖碳汇影响因素地理探测器福建省