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Small but mighty:Empowering sodium/potassium-ion battery performance with S-doped SnO2 quantum dots embedded in N,S codoped carbon fiber network

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Carbon Energy 2024年第5期6卷 186-200页

作者： Shengnan He Hui Wu Shuang Li ke Liu yaxiong Yang Hongge Pan Xuebin Yu Institute of Science and Technology for New Energy Xi'an Technological UniversityXi'anChina Department of Materials Science Fudan UniversityShanghaiChina Wanxiang A123 Systems Corporation HangzhouChina School of Material Science and Engineering Shanghai UniversityShanghaiChina

SnO_(2) has been extensively investigated as an anode material for sodium-ion batteries(SIBs)and potassium-ion batteries(PIBs)due to its high Na/K storage capacity,high abundance,and low toxicity.However,the sluggish reaction kinetics,low electronic conductivity,and large volume changes during charge and discharge hinder the practical applications of SnO_(2)-based electrodes for SIBs and PIBs.Engineering rational structures with fast charge/ion transfer and robust stability is important to overcoming these challenges.Herein,S-doped SnO_(2)(S-SnO_(2))quantum dots(QDs)(≈3 nm)encapsulated in an N,S codoped carbon fiber networks(S-SnO_(2)-CFN)are rationally fabricated using a sequential freeze-drying,calcination,and S-doping strategy.Experimental analysis and density functional theory calculations reveal that the integration of S-SnO_(2) QDs with N,S codoped carbon fiber network remarkably decreases the adsorption energies of Na/K atoms in the interlayer of SnO_(2)-CFN,and the S doping can increase the conductivity of SnO_(2),thereby enhancing the ion transfer kinetics.The synergistic interaction between S-SnO_(2) QDs and N,S codoped carbon fiber network results in a composite with fast Na+/K+storage and extraordinary long-term cyclability.Specifically,the S-SnO_(2)-CFN delivers high rate capacities of 141.0 mAh g^(−1) at 20 A g^(−1) in SIBs and 102.8 mAh g^(−1) at 10 A g^(−1) in PIBs.Impressively,it delivers ultra-stable sodium storage up to 10,000 cycles at 5 A g^(−1) and potassium storage up to 5000 cycles at 2 A g^(−1).This study provides insights into constructing metal oxide-based carbon fiber network structures for high-performance electrochemical energy storage and conversion devices.

关键词： carbon fiber network heteroatom doping potassium-ion battery sodium-ion battery S-SnO2 quantum dot

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Actuation Spaces Synthesis of Lower-Mobility Parallel Mechanisms Based on Screw Theory

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Chinese Journal of Mechanical Engineering 2021年第1期34卷 280-291页

作者： Shihua Li Yanxia Shan Jingjun Yu yaxiong ke Hebei Provincial key Laboratory of Parallel Robot and Mechatronic Systems Yanshan UniversityQinhuangdao 066004China School of Mechanical Engineering Yanshan UniversityQinhuangdao 066004China School of Liren Yanshan UniversityQinhuangdao 066004China Robotics Institute Beihang UniversityBeijing 100191China

The lower-mobility parallel mechanism has been widely used in the engineering field due to its numerous excellent characteristics.However,little work has been devoted to the actuator selection and placement that best satisfy the system's functional requirements during concept design.In this study,a unified approach for synthesizing the actuation spaces of both rigid and flexure parallel mechanisms has been presented,and all possible combinations of inputs could be obtained,laying a theoretical foundation for the subsequent optimization of inputs.According to the linear independence of actuation space and constraint space of the lower-mobility parallel mechanism,a general expression of actuation spaces in the format of screw systems is deduced,a unified synthesis process for the lower-mobility parallel mechanism is derived,and the efficiency of the method is validated with two selective examples based on screw theory.This study presents a theoretical framework for the input selection problems of parallel mechanisms,aiming to help designers select and place actuators in a correct and even optimal way after the configuration design.

关键词： Lower-mobility parallel mechanism Screw theory Actuation space Actuator placement Input selection

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An innovative joint interface design for reducing intermetallic compounds and improving joint strength of thick plate friction stir welded Al/Mg joints

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Journal of Magnesium and Alloys 2023年第9期11卷 3151-3160页

作者： Yang Xu Liming ke Yuqing Mao Jifeng Sun yaxiong Duan Limin Yu National Defence key Discipline Laboratory of Light Alloy Processing Science and Technology Nanchang Hangkong UniversityNanchang 330063PR China State key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072PR China

Friction stir welding of dissimilar Al/Mg thick plates still faces severe challenges, such as poor formability, formation of thick intermetallic compounds, and low joint strength. In this work, two joint configurations, namely inclined butt(conventional butt) and serrated interlocking(innovative butt), are proposed for improving weld formation and joint quality. The results show that a continuous and straight intermetallic compound layer appears at the Mg side interface in conventional butt joint, and the maximum average thickness reaches about 60.1 μm.Additionally, the Mg side interface also partially melts, forming a eutectic structure composed of Mg solid solution and Al_(12)Mg_(17) phase.For the innovative butt joint, the Mg side interface presents the curved interlocking feature, and intermetallic compounds can be reduced to less than 10 μm. The joint strength of innovative butt joint is more than three times that of conventional butt joint. This is due to the interlocking effect and thin intermetallic compounds in the innovative joint.

关键词： Al/Mg joint Friction stir welding Thick plate Intermetallic compounds Joint strength

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TOC estimation from logging data using principal component analysis

能源地球科学(英文)

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能源地球科学(英文) 2023年第4期4卷 1-8页

作者： yaxiong Zhang Gang Wang Xindong Wang Haitao Fan Bo Shen ke Sun Petroleum Exploration and Production Research Institute SINOPECBeijing102206China Research Institute of Exploration and Development Xinjiang Oilfield CompanyKaramay834000China Materials and Equipment Center of CNPC Well Logging Company Xi'an710000China Geophysics and Oil Resource Institute Yangtze UniversityWuhan430010China Library Yangtze UniversityWuhan430010China

Total organic carbon(TOC)content is one of the most important parameters for characterizing the quality of source rocks and assessing the hydrocarbon-generating potential of shales.The Lucaogou Formation shale reservoirs in the Jimusaer Sag,Junggar Basin,NW China,is characterized by extremely complex lithology and a wide variety of mineral compositions with source rocks mainly consisting of carbonaceous mudstone and dolomitic mudstone.The logging responses of organic matter in the shale reservoirs is quite different from those in conventional reservoirs.Analyses show that the traditional△logR method is not suitable for evaluating the TOC content in the study area.Analysis of the sensitivity characteristics of TOC content to well logs reveals that the TOC content has good correlation with the separation degree of porosity logs.After a dimension reduction processing by the principal component analysis technology,the principal components are determined through correlation analysis of porosity logs.The results show that the TOC values obtained by the new method are in good agreement with that measured by core analysis.The average absolute error of the new method is only 0.555,much less when compared with 1.222 of using traditional△logR method.The proposed method can be used to produce more accurate TOC estimates,thus providing a reliable basis for source rock mapping.

关键词： Total organic carbon Principal component analysis Separation degree Source rocks Shale oil

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Multiple Resonance Thermally Activated Delayed Fluorescence Sensitizers Enable Green-toUltraviolet Photon Upconversion:Application in Photochemical Transformations

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CCS Chemistry 2022年第12期4卷 3852-3863页

作者： yaxiong Wei ke Pan Xiaosong Cao Yuanming Li Xiaoguo Zhou Chuluo Yang Shenzhen key Laboratory of Polymer Science and Technology College of Materials Science and EngineeringShenzhen UniversityShenzhen 518060 School of Physics and Electronic Information Anhui Normal UniversityWuhuAnhui 241000 Department of Chemical Physics University of Science and Technology of ChinaHefeiAnhui 230026

Efficient visible-to-ultraviolet(UV)triplet-triplet annihilation upconversion(TTA-UC)with large anti-Stokes shift is highly promising for solar-powered and indoor applications.Nonetheless,the excitationwavelengthis confined to the blue region(kes shift up to 1.05 eV,upconversion quantum yield up to 8.6%,and threshold excitation intensity as low as 9.2 mW cm^(−2) in solution.The TTA-UC pairs were applied as internal or external sources of UV photons to trigger energy-demanding photopolymerization and photoligation reactions even under excitation of low-power-density green light-emitting diode light,revealing the broad utility of thesemolecular upconverters.This work unlocks the huge potential of MR-TADF-type sensitizers in upconversion applications.

关键词： triplet-triplet annihilation upconversion visible-to-ultraviolet upconversion multiple resonance photochemical reactions

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飞秒-纳秒双脉冲激光诱导击穿光谱(LIBS)技术对合金的定量分析

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中国无机分析化学 2024年第2期14卷 214-222页

作者：何亚雄王一钦韩晶阳许淼陈楠谭金宝温起帆柯川高亮才来中赵栋烨核工业西南物理研究院成都610225 西南交通大学电气工程学院成都611731 哈尔滨工业大学物理学院哈尔滨150006

激光诱导击穿光谱(Laser-induced breakdown spectroscopy,LIBS)技术几乎不受聚变环境中的强磁场影响,是一种最有希望实现托卡马克装置中面向等离子体材料(Plasma facing materials,PFMs)原位在线诊断的技术,已被用于多个托卡马克PFMs... 详细信息

激光诱导击穿光谱(Laser-induced breakdown spectroscopy,LIBS)技术几乎不受聚变环境中的强磁场影响,是一种最有希望实现托卡马克装置中面向等离子体材料(Plasma facing materials,PFMs)原位在线诊断的技术,已被用于多个托卡马克PFMs壁诊断。然而,LIBS技术对PFMs表面元素的探测限、定量分析以及PFMs的服役状态判定依旧面临很大挑战。采用同轴飞秒-纳秒激光协同技术,建立了飞秒-纳秒双脉冲激光诱导击穿光谱(fs-ns-DP-LIBS)技术,通过高峰值功率、低激光能量的飞秒激光诱导等离子体,再用纳秒激光增强常规单脉冲LIBS技术信号发射强度,进而提升常规单脉冲LIBS的探测灵敏度,同时结合6种合金标准样品,采用fs-ns-DP-LIBS技术对样品中的主要元素进行了定量分析,并进一步结合机器学习方法对6种合金进行种类判别。结果显示:在纳秒单脉冲和飞秒单脉冲LIBS检测中,Ni、Fe和Mo在400~800 nm波段没有观察到明显特征峰,仅观察到Cr的特征峰;在飞秒-纳秒脉冲间2μs延时,NiⅠ498.02 nm、FeⅠ517.16 nm、FeⅠ523.85 nm、MoⅠ588.83 nm和MoⅠ603.07 nm均被激发,且Cr的特征峰强度增强明显;并且相比对纳秒单脉冲LIBS技术,Cr的信号强度提高约7倍。定量分析结果显示,fs-ns-DP-LIBS技术绘制的定标曲线拟合度(R ^(2))更高,且Cr的探测限提高约3.5倍。进一步采用决策树、最近邻、线性判别和支持向量机等算法对6种合金进行了分类研究,线性判别和支持向量机的分类预测准确率大于99%。研究有望为原位LIBS技术诊断PFMs壁表面元素、定量分析及其服役状态判定提供检测方法。

关键词：托卡马克激光诱导击穿光谱飞秒-纳秒双脉冲定量分析合金

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2004-2022年甘肃省审定小麦品种情况分析与展望

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麦类作物学报 2024年第2期44卷 268-277页

作者：马玲汪军成李鹏程张宏姚立蓉司二静杨轲孟亚雄马小乐李葆春尚勋武王化俊省部共建干旱生境作物学国家重点实验室/甘肃省作物遗传改良与种质创新重点实验室兰州730070 甘肃农业大学农学院兰州730070 甘肃农业大学生命科学技术学院兰州730070

为了给甘肃省高产优质小麦新品种的选育提供参考依据,对以甘肃省2004-2022年审定的284个小麦品种的基本情况和抗条锈病性进行了分析,并统计了生育期、株高和产量水平。结果表明,甘肃省近19年审定的小麦品种数量呈现波动上升趋势,育种单... 详细信息

为了给甘肃省高产优质小麦新品种的选育提供参考依据,对以甘肃省2004-2022年审定的284个小麦品种的基本情况和抗条锈病性进行了分析,并统计了生育期、株高和产量水平。结果表明,甘肃省近19年审定的小麦品种数量呈现波动上升趋势,育种单位主力为省内科研院所,联合育种呈现波动上升趋势,表明科研工作者对小麦品种选育具有较高的积极性;通过高使用频率直接亲本统计分析,发现甘肃省审定的小麦品种亲本配置组合主要来自主栽品种和人工创制的种质资源,并发现5个高使用频率直接亲本,表明近19年甘肃省审定品种遗传基础较窄;育成品种主要采用的育种方式为杂交育种,且育种方式趋于单一,表明今后要加强创新育种方式;审定的小麦品种以冬小麦为主,其中80.2%集中在陇东泾河上游川塬山地冬小麦区和陇南渭河上游河谷山地冬小麦区,而审定的春小麦97.9%则集中在河西内陆河灌溉春小麦区和陇中干旱川山春小麦区;小麦抗病性方面,审定品种对条锈病的抗性水平相对较好,但年际间波动较大;春小麦生育期年平均增加0.15 d,而冬小麦生育期年平均减少0.46 d;株高年平均降低1.10 cm,平均产量呈逐年上升趋势,年均增长47.25 kg·hm^(-2),其中2012年产量最高,为8 136.2 kg·hm^(-2);千粒重、穗粒数和有效穗数均呈现逐渐上升趋势,但穗粒数变化不大,年均增加0.08粒,千粒重年均增加2.71 g,有效穗数年平均增加1.29个。综上,在后续的育种工作中,可结合不同育种方式,更进一步选育出高产、优质和高抗的小麦新品种。

关键词：甘肃省小麦审定品种

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Quantitative analysis and time-resolved characterization of simulated tokamak exhaust gas by laser-induced breakdown spectroscopy

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Plasma Science and Technology 2022年第4期24卷 188-197页

作者：何亚雄许涛张勇柯川赵勇刘曙 School of Physics and Energy Fujian Normal UniversityFuzhou 350117People's Republic of China Center for Superconducting and New Energy Research and Development Southwest Jiaotong UniversityChengdu 610031People's Republic of China Fujian Provincial Collaborative Innovation Center for Advanced High-Field Superconducting Materials and Engineering Fuzhou 350117People's Republic of China Shandong Dong Yi Optoelectronic Instrument Co. LtdYantai 264670People's Republic of China Technical Center for Industrial Product and Raw Material Inspection and Testing Shanghai CustomsShanghai 200135People's Republic of China

Tokamak exhaust is an important part of the deuterium-tritium fuel cycle system in fusion reactions.In this work,we present a laser-induced breakdown spectroscopy(LIBS)-based method to monitor the gas compositions from the exhaust system in the tokamak device.Helium(He),a main impurity in the exhaust gas,was mixed with hydrogen(H_(2))in different ratios through a self-designed gas distribution system,and sealed into a measurement chamber as a standard specimen.A 532 nm wavelength laser pulse with an output power of 100 mJ was used for plasma excitation.The time-resolved LIBS is used to study the time evolution characteristics of the signal strength,signal-to-background ratio(SBR),signal-to-noise ratio(SNR)and relative standard deviation(RSD)of the helium and hydrogen characteristic lines.The Boltzmann twoline method was employed to estimate the plasma temperature of laser-induced plasma(LIP).The Stark-broadened profile of He I 587.56 nm was exploited to measure the electron density.From these studies,an appropriate time was determined in which the low RSD%was consistent with the high signal-to-noise ratio.The He I 587.56 nm and Hαemission lines with good signalto-noise ratio were extracted from the spectrum and used in the external standard method and internal standard method for quantitative analysis.The test results for mixed gas showed that the average relative error of prediction was less than 11.15%,demonstrating the great potential of LIBS in detecting impurities in plasma exhaust gas.

关键词： exhaust gas plasma diagnostics LIBS quantitative analysis

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基于CEL方法的Al/Mg搅拌摩擦焊温度场及材料混合流动研究

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稀有金属材料与工程 2023年第7期52卷 2565-2572页

作者：段亚雄刘其鹏高月华李雯柯黎明牛鹏亮徐洋南昌航空大学轻合金加工科学与技术国防重点学科实验室江西南昌330063 南昌航空大学江西省航空构件成形与连接重点实验室江西南昌330063 西北工业大学材料学院陕西西安710072 哈尔滨工业大学先进焊接与连接国家重点实验室黑龙江哈尔滨150001

基于耦合欧拉-拉格朗日(coupled Eulerian-Lagrangion,CEL)方法建立AA5A06铝合金与AZ31B镁合金对接搅拌摩擦焊接(friction stir welding,FSW)的全热力耦合数值模型,并结合试验测试对Al/Mg异种金属FSW过程的温度场及材料混合流动特征进... 详细信息

基于耦合欧拉-拉格朗日(coupled Eulerian-Lagrangion,CEL)方法建立AA5A06铝合金与AZ31B镁合金对接搅拌摩擦焊接(friction stir welding,FSW)的全热力耦合数值模型,并结合试验测试对Al/Mg异种金属FSW过程的温度场及材料混合流动特征进行研究。数值模拟所得特征点的温度循环曲线、焊缝表面形貌以及横截面上异种材料的混合分布状态均与试验结果吻合良好。在此基础上,采用质点追踪法对材料混合流动行为进行了深入分析。结果表明,高温区集中分布在轴肩下方区域,返回侧(镁侧)温度较低,温度梯度较大。焊缝区上表面材料熔合线偏向于前进侧(铝侧)。搅拌针附近材料流动剧烈,前进侧和返回侧的大部分材料都较均匀地沉积于搅拌针后方。前进侧与返回侧材料在水平和竖直方向上的交叉混合流动,促使最终形成了2种材料“咬合式”的结合界面特征。

关键词：搅拌摩擦焊铝/镁异种合金耦合欧拉-拉格朗日方法材料混合流动

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Self-absorption effects of laser-induced breakdown spectroscopy under different gases and gas pressures

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Plasma Science and Technology 2023年第2期25卷 155-162页

作者：王崧宁张殿鑫陈楠何亚雄张红柯川许涛陈永亮赵勇 Superconductivity and New Energy R&D Center Southwest Jiaotong UniversityChengdu 610036People's Republic of China school of Physical Science and Technology Southwest Jiaotong UniversityChengdu 610036People's Republic of China School of Physics and Energy Fujian Normal UniversityFuzhou 350117People's Republic of China

The self-absorption effect is one of the main factors affecting the quantitative analysis accuracy of laser-induced breakdown spectroscopy.In this paper,the self-absorption effects of laserinduced 7050 Al alloy plasma under different pressures in air,Ar,and N2have been studied.Compared with air and N2,Ar significantly enhances the spectral signal.Furthermore,the spectral self-absorption coefficient is calculated to quantify the degree of self-absorption,and the influences of gas species and gas pressure on self-absorption are analyzed.In addition,it is found that the spectral intensity fluctuates with the change of pressure of three gases.It can also be seen that the fluctuation of spectral intensity with pressure is eliminated after correcting,which indicates that the self-absorption leads to the fluctuation of spectral intensity under different pressures.The analysis shows that the evolution of optical thin spectral lines with pressure in different gases is mainly determined by the gas properties and the competition between plasma confinement and Rayleigh–Taylor instability.

关键词： self-absorption coefficient ambient gases gas pressure laser-induced breakdown spectroscopy

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