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Regulating surface electron structure of PtNi nanoalloy via boron doping for high‐current‐density Li‐O2 batteries with low overpotential and long‐life cyclability

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SmartMat 2024年第1期5卷 110-120页

作者： yajun ding Yuanchao Huang Yuejiao Li Tao Zhang Zhong‐Shuai Wu State Key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalianChina State Key Laboratory of Silicon Materials and School of Materials Science and Engineering Zhejiang UniversityHangzhouChina Institute of Advanced Semiconductors Hangzhou Innovation CenterZhejiang UniversityHangzhouChina University of Chinese Academy of Sciences BeijingChina State Key Laboratory of High Performance Ceramics and Superfine Microstructure Shanghai Institute of CeramicsChinese Academy of SciencesShanghaiChina Dalian National Laboratory for Clean Energy Chinese Academy of SciencesDalianChina

The realization of high‐efficiency,reversible,stable,and safe Li‐O2 batteries is severely hindered by the large overpotential and side reactions,especially at high rate ***,rational design of cathode catalysts with high activity and stability is crucial to overcome the terrible issues at high current ***,we report a surface engineering strategy to adjust the surface electron structure of boron(B)‐doped PtNi nanoalloy on carbon nanotubes(PtNiB@CNTs)as an efficient bifunctional cathodic catalyst for high‐rate and long‐life Li‐O2 ***,the Li‐O2 batteries assembled with as‐prepared PtNiB@CNT catalyst exhibit ultrahigh discharge capacity of 20510 mA·h/g and extremely low overpotential of 0.48 V at a high current density of 1000 mA/g,both of which outperform the most reported Pt‐based catalysts ***,our Li‐O2 batteries offer excellent rate capability and ultra‐long cycling life of up to 210 cycles at 1000 mA/g under a fixed capacity of 1000 mA·h/g,which is two times longer than those of Pt@CNTs and PtNi@***,it is revealed that surface engineering of PtNi nanoalloy via B doping can efficiently tailor the electron structure of nanoalloy and optimize the adsorption of oxygen species,consequently delivering excellent Li‐O2 battery ***,this strategy of regulating the nanoalloy by doping nonmetallic elements will pave an avenue for the design of high‐performance catalysts for metal‐oxygen batteries.

关键词： B doping bifunctional catalyst Li‐O2 battery low charge overpotential PtNi nanoalloy

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含CL-20的微孔发射药的设计及性能研究

爆破器材 2024年第4期53卷 37-44页

作者：郏杭生崔立宝丁亚军李成龙顾晗王晓倩南京理工大学化学与化工学院江苏南京210094 驻太原地区防化军代室山西太原030000

为了研究六硝基六氮杂异伍兹烷(CL-20)含量及微孔结构对发射药性能的影响,采用超临界发泡工艺设计并制备了含CL-20的微孔发射药。利用扫描电子显微镜(SEM)观察了发射药的形貌结构,通过密闭爆发器实验、简支梁冲击仪和摩擦感度仪等研究... 详细信息

为了研究六硝基六氮杂异伍兹烷(CL-20)含量及微孔结构对发射药性能的影响,采用超临界发泡工艺设计并制备了含CL-20的微孔发射药。利用扫描电子显微镜(SEM)观察了发射药的形貌结构,通过密闭爆发器实验、简支梁冲击仪和摩擦感度仪等研究了发射药的燃烧性能、力学性能和感度。结果表明:CL-20颗粒均匀地分散在样品表面及内部,样品内部形成了大量尺寸为0.08~2.00μm的泡孔;CL-20颗粒的加入降低了样品的力学性能,CL-20含量越高,样品的抗冲击强度与拉伸强度降低得越明显;随着CL-20含量的增加,样品的摩擦感度和静电感度会随之升高,燃速也会得到一定程度的提高;经发泡改性后的样品的力学性能弱于未经发泡改性的样品;发泡工艺能够抑制因CL-20含量上升而导致的感度上升;经过发泡后的样品,燃烧性能得到了显著提升,样品的L-B(相对动态活度-相对压力)曲线在B为0~0.10范围内即出现急速上升趋势,L在B为0.14~0.18范围内达到最大,CL-20质量分数为15%和20%时,L_(max)分别为14.39 MPa^(-1)·s^(-1)和9.70 MPa^(-1)·s^(-1)。

关键词：微孔发泡超临界流体发射药 CL-20 燃烧感度力学性能

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Multi-scale simulation of diffusion behavior of deterrent in propellant

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Chinese Journal of Chemical Engineering 2023年第2期54卷 29-35页

作者： Pan Huang Zekai Zhang Yuxin Chen Changwei Liu Yong Zhang Cheng Lian yajun ding Honglai Liu State Key Laboratory of Chemical Engineering Shanghai Engineering Research Center of Hierarchical NanomaterialsSchool of Chemical EngineeringEast China University of Science and TechnologyShanghai 200237China School of Chemistry and Molecular Engineering East China University of Science and TechnologyShanghai 200237China School of Chemistry and Chemical Engineering Nanjing University of Science and TechnologyNanjing 210094China

Concentration distribution of the deterrent in single-base propellant during the process of firing plays an important role in the ballistic properties of gun propellant in weapons. However, the diffusion coefficient calculated by molecular dynamics(MD) simulation is 6 orders of magnitude larger than the experimental values. Meanwhile, few simple and comprehensive theoretical models can explain the phenomenon and accurately predict the concentration distribution of the propellant. Herein, an onion model combining with MD simulation and finite element method of diffusion in propellants is introduced to bridge the gap between the experiments and simulations, and correctly predict the concentration distribution of deterrent. Furthermore, a new time scale is found to characterize the diffusion process. Finally, the time-and position-depended concentration distributions of dibutyl phthalate in nitrocellulose are measured by Raman spectroscopy to verify the correctness of the onion model. This work not only provides guidance for the design of the deterrent, but could be also extended to the diffusion of small molecules in polymer with different crystallinity.

关键词： Multi-scale simulation Diffusion Deterrent Propellant Onion model Molecular dynamics simulation

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高大毛壳对硝化纤维素的降氮机理

兵工学报 2024年第3期45卷 875-884页

作者：黄娟薛会会张阿磊陈可泉周杰丁亚军肖忠良南京理工大学化学与化工学院江苏南京210094 南京理工大学特种能源材料教育部重点实验室江苏南京210094 南京工业大学生物与制药工程学院江苏南京211816

针对废旧火药存在严重的安全隐患问题,通过对硝化纤维素(Nitrocellulose,NC)生产的废液处理池及其周边进行采样、富集、驯化和分离纯化,获得5株能够降低NC含氮量的微生物,并对其中降氮效果最佳的高大毛壳进行时间优化实验,发现随着时间... 详细信息

针对废旧火药存在严重的安全隐患问题,通过对硝化纤维素(Nitrocellulose,NC)生产的废液处理池及其周边进行采样、富集、驯化和分离纯化,获得5株能够降低NC含氮量的微生物,并对其中降氮效果最佳的高大毛壳进行时间优化实验,发现随着时间的延长,NC含氮量可从13.06%降至10.83%,X射线光电子能谱结果显示NC表面氮元素含量逐渐降低;利用傅里叶变换红外光谱、显微共聚焦拉曼仪和凝胶渗透色谱仪对NC分子结构和分子量进行表征,红外光谱表明高大毛壳与O—NO 2发生水解反应,导致NC在3400 cm^(-1)左右的—OH峰强逐渐增大,拉曼光谱图显示NC含能基团(O—NO 2)的强度发生了显著降低,同时通过凝胶色谱发现,高大毛壳可使NC的数均分子质量和重均分子质量分别降低2.34%和6.40%。为进一步确定作用于NC的生物酶,利用胞外酶、胞内酶的分离以及硫酸铵梯度沉淀实验,证明0~30%硫酸铵沉淀的胞外酶能够有效降低NC的含氮量;高大毛壳对降低NC含氮量的显著作用,使其在废旧火药的再利用、高渐增发射药的生物脱硝等方面具有广阔的应用前景。

关键词：硝化纤维素高大毛壳含氮量分子结构生物脱硝

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北仑区县域医共体推进医防融合的实践与成效

中国农村卫生事业管理 2024年第5期44卷 372-374页

作者：叶冬仙徐春霞丁亚君陈史敏叶云贺秀君北仑区人民医院医疗健康服务集团浙江宁波315800

慢性非传染性疾病是影响人类健康生活的主要疾病,对家庭和社会造成沉重负担,加强慢病管理至关重要。文章介绍了在县域医共体框架下北仑区人民医院医疗健康服务集团慢性病“六师共管”的工作模式、智慧化服务和医管科研融合等特色做法,... 详细信息

慢性非传染性疾病是影响人类健康生活的主要疾病,对家庭和社会造成沉重负担,加强慢病管理至关重要。文章介绍了在县域医共体框架下北仑区人民医院医疗健康服务集团慢性病“六师共管”的工作模式、智慧化服务和医管科研融合等特色做法,从而有效提升两慢病的规范管理率和控制率,促进家庭医生签约服务、双向转诊、远程医疗,实现“六师共管”成效,为推进县域医共体慢病医防融合提供了实践经验。

关键词：县域医共体慢性病六师共管医防融合

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氢解脱苄反应钯基合金催化剂研究进展

工业催化 2024年第7期32卷 1-8页

作者：丁亚军李思怡王毅刘瑶杨旭陈威余业建宋建伟辽宁庆阳特种化工有限公司辽宁辽阳111002

氢解脱苄反应是有机合成较为关键的一步工艺。然而,贵金属钯(Pd)的使用以及使用过程中不可避免的流失,极大地增加了产品的成本。为此,开发高性能、长寿命、低成本氢解催化剂成为提升产品竞争力的核心技术。其中,Pd基合金催化剂由于协同... 详细信息

氢解脱苄反应是有机合成较为关键的一步工艺。然而,贵金属钯(Pd)的使用以及使用过程中不可避免的流失,极大地增加了产品的成本。为此,开发高性能、长寿命、低成本氢解催化剂成为提升产品竞争力的核心技术。其中,Pd基合金催化剂由于协同效应、高稳定性和非贵金属部分替代而成为更具发展潜力的策略。因此,从氢解脱苄催化反应机理入手,综述近年来氢解脱苄反应Pd基合金催化剂取得的研究进展,讨论Pd基合金催化剂的设计原则、制备方法和合金效应,结合工业化氢解脱苄反应的特征,对Pd基合金催化剂的设计、制备、应用、回收作出总结和展望。

关键词：催化剂工程氢解脱苄反应有机合成 Pd基合金协同效应合金效应

Efficient oxygen reduction reaction by a highly porous,nitrogen-doped carbon sphere electrocatalyst through space confinement effect in nanopores

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Journal of Advanced Ceramics 2021年第4期10卷 714-728页

作者： Zheyang MO Weiyi YANG Shuang GAO Jian Ku SHANG yajun ding Wuzhu SUN Qi LI School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Key Laboratory of Advanced Technologies of Materials(Ministry of Education) School of Materials Science and EngineeringSouthwest Jiaotong UniversityChengdu 610031China School of Materials Science and Engineering Shandong University of TechnologyZibo 255000China

A highly porous nitrogen-doped carbon sphere(NPC)electrocatalyst was prepared through the carbonization of biomass carbon spheres mixed with urea and zinc chloride in N_(2) *** sample carbonized at.1000℃ demonstrates a superior oxygen reduction reaction(ORR)performance over the Pt/C electrocatalyst,while its contents of pyridinic nitrogen and graphitic nitrogen are the lowest among samples synthesized at the same or lower carbonization *** unusual result is explained by a space confinement effect from the microporous and mesoporous structures in the microflakes,which induces the further reduction of peroxide ions or other oxygen species produced in the first step reduction to water to have the preferred overall four electron reduction ORR *** work demonstrates that in addition to the amount or species of its aptive sites,the space confinement can be a new approach to enhance the ORR performance of precious-metal-free,nitrogen-doped carbon electrocatalysts.

关键词： precious-metal-free electrocatalyst biomass resource space confinement effect 2e+2e pathway oxygen reduction reaction(ORR)

Advanced design of cathodes and interlayers for high-performance lithium-selenium batteries

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SusMat 2021年第3期1卷 393-412页

作者： Yanfeng Dong Pengfei Lu yajun ding Haodong Shi Xinliang Feng Zhong-Shuai Wu State Key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalianP.R.China Department of Chemistry College of SciencesNortheastern UniversityShenyangP.R.China Center for Advancing Electronics Dresden&Department of Chemistry and Food Chemistry Technische Universität DresdenDresdenGermany Dalian National Laboratory for Clean Energy Chinese Academy of SciencesDalianP.R.China

Lithium-selenium(Li-Se)batteries have attracted ever-increasing attention owing to high volumetric capacity comparable to lithium-sulfur batteries and excellent electronic conductivity of ***,unsatisfactory energy density and cycling life of Li-Se batteries mainly caused by low utilization of Se and shuttle effect of polyselenides(PSes)seriously prevent their commercial ***,this work systematically reviews the recent advances of the state-of-the-art cathodes and interlayers in high-performance Li-Se ***,the fundamental chemistries of Li-Se batteries are introduced in terms of var-ious Se precursors and electrochemical ***,the main strategies in cathodes and interlayers for addressing poor conductivity of Se and shuttle effects of PSes are summarized as three-dimensional conductive skeletons for Se,physical confinement of Se,chemisorption and catalytic conversion of PSes,and free-standing interlayers and interlayers on ***,the synthesis strategies and enhanced electrochemical performance are specially exemplified to highlight the possible enlightenments for constructing advanced cathodes and ***,the future challenges and perspectives of advanced cathodes and interlayers in high-performance Li-Se batteries are briefly discussed.

关键词： cathodes energy storage high energy density interlayers lithium-selenium batteries

Research and development of new neodymium laser glasses

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High Power Laser Science and Engineering 2017年第1期5卷 1-6页

作者： Dongbing He Shuai Kang Liyan Zhang Lin Chen yajun ding Qianwen Yin Lili Hu Shanghai Institute of Optics and Fine Mechanics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China Laser Fusion Research Center Chinese Academy of Engineering PhysicsMianyangSichuan 621900China

This work presents a brief introduction on three kinds of newly developed Nd^(3+)-doped laser glasses in Shanghai Institute of Optics and Fine Mechanics(SIOM), China. Two Nd^(3+)-doped phosphate glasses with lower thermal expansion coefficient and thermal shock resistance 4 times higher than that of N31 glass are developed for laser ***:Silicate and Nd:Aluminate glasses with peak emission wavelength at 1061 and 1065 nm, effective emission bandwidth of 34 and 50 nm, respectively, are developed for Exawatt-class laser system application. Fluorophosphate glasses with low nonlinear refractive index(n_2=0.6–0.86) and long fluorescence lifetime(430–510 μs) are investigated for the purpose of decreasing B integral in high-power laser system. The properties of all these glasses are presented and compared with those of commercial neodymium laser glasses.

关键词： aluminate glass fluorophosphate glass high-power laser neodymium laser glass phosphate glass silicate glass