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Synthesis of nearly spherical AlN particles by an in-situ nitriding combustion route

Journal of Advanced Ceramics 2021年第2期10卷 291-300页

作者： Zhilei Wei kang Li Bangzhi Ge Chaowei Guo hongyan Xia Yajie Guo Zhongqi Shi State Key Laboratory for Mechanical Behavior of Materials Xi’an Jiaotong UniversityXi’an710049China Engineering Research Center of Transportation Materials of Ministry of Education School of Materials Science and EngineeringChang’an UniversityXi’an710064China

Spherical AlN powders with micrometer size have attracted great attention owing to their good fluidity and dispersity. However, the industrial preparation methods usually require high temperature and long soaking time, which lead to the high cost and limit the wide application of the products. Herein, nearly spherical AlN particles with the average size of 2.5 μm were successfully synthesized via an in-situ combustion synthesis method. The effect of N_(2) pressure, NH_(4)Cl content, and Al particle size on the combustion reaction procedure, phase composition, and microstructure of the products was systematically investigated. The results showed that the decreased N_(2) pressure, increased NH_(4)Cl content, and Al particle size led to the decreasing of combustion temperature and speed, which further affected the morphology of the products. As a result, low N_(2) pressure(0.2 MPa), a small amount of NH4Cl(0.5 wt%), and fine Al particles(~2.5 μm) contributed to a moderate combustion temperature and facilitated the formation of nearly spherical AlN particles. In addition, based on the gas-releasing assisted quenching experiments and thermo-kinetic analysis, a two-step growth mechanism for the nearly spherical AlN particles was rationally proposed. The present method shows the advantages of low cost and high efficiency for preparing nearly spherical AlN particles, which can be used as raw materials for electronic substrates and fillers for packaging materials.

关键词： combustion synthesis AlN microstructure growth mechanism

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Microstructure and Mechanical Properties of a Spray-Formed Superalloy

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Acta Metallurgica Sinica(English Letters) 2014年第6期27卷 1063-1069页

作者： Fuwei kang Fuyang Cao Xuemin Zhang hongyan Yue Yicheng Feng School of Materials Science and Engineering Harbin University of Science and Technology School of Materials Science and Engineering Harbin Institute of Technology

The microstructural evolution and mechanical properties of a spray-formed superalloy were studied in this paper. Based on a better understanding of the microstructural evolution of the spray-formed superalloy during solution treatment, an optimum solution treatment process was obtained, namely, at 1,140 °C for 6 h, and air cooling（AC）. The effects of the ageing treatments on the mechanical properties of the post-solution-treated spray-formed superalloy were evaluated using ageing harden curves and tensile testing. The results indicated that the maximum hardness value was achieved at 850 °C for 8 h, AC. Due to co-precipitation of primary and secondary c0 precipitates during the heat treatment,the spray-formed superalloy obtained an excellent combination of yield strength（YS = 1,110 MPa）, ultimate tensile strength（UTS = 1,503 MPa）, ductility（elongation, EL = 21%） and excellent stress rupture properties at 650 °C（UTS = 1,209 MPa, EL = 15.8%）. The heat treatment also improved the rupture life at 650 °C/950 MPa and 750 °C/539 MPa up to 140 h without rupturing. The tensile-fractured surfaces exhibit ductile transgranular failure feature. The optimum heat treatment process was determined to be 1,140 °C/6 h＋850 °C/8 h＋AC.

关键词： Spray-formed superalloy Microstructure Ageing harden Mechanical properties

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Highly Conductive Proton Selectivity Membrane Enabled by Hollow Carbon Sieving Nanospheres for Energy Storage Devices

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Engineering 2023年第9期28卷 69-78页

作者： kang Huang Shuhao Lin Yu Xia Yongsheng Xia Feiyan Mu Yuqin Lu hongyan Cao Yixing Wang Weihong Xing Zhi Xu State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical EngineeringNanjing Tech UniversityNanjing 211816China State Key Laboratory of Chemical Engineering School of Chemical EngineeringEast China University of Science and TechnologyShanghai 200237China

Ion conductive membranes(ICMs)with highly conductive proton selectivity are of significant importance and greatly desired for energy storage devices.However,it is extremely challenging to construct fast proton-selective transport channels in ICMs.Herein,a membrane with highly conductive proton selectivity was fabricated by incorporating porous carbon sieving nanospheres with a hollow structure(HCSNs)in a polymer matrix.Due to the precise ion sieving ability of the microporous carbon shells and the fast proton transport through their accessible internal cavities,this advanced membrane presented a proton conductivity(0.084 S·cm^(-1))superior to those of a commercial Nation 212(N212)membrane(0.033S·cm^(-1))and a pure polymer membrane(0.049 S·cm^(-1)).The corresponding proton selectivity of the membrane(6.68×10^(5) S·min·cm^(-3))was found to be enhanced by about 5.9-fold and 4.3-fold,respectively,compared with those of the N212 membrane(1.13×10^(5) S·min·cm^(-3))and the pure membrane(1.56×10^(5) S·min·cm^(-3)).Low-field nuclear magnetic resonance(LF-NMR)clearly revealed the fast protonselective transport channels enabled by the HCSNs in the polymeric membrane.The proposed membrane exhibited an outstanding energy efficiency(EE)of 84%and long-term stability over 1400 cycles with a0.065%capacity decay per cycle at 120 mA·cm^(-2) in a typical vanadium flow battery(VFB)system.

关键词： Ion conductive membrane Hollow carbon sieving nanosphere Proton transport channel Flow battery

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Surface curvature-confined strategy to ultrasmall nickel-molybdenum sulfide nanoflakes for highly efficient deep hydrodesulfurization

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Nano Research 2020年第3期13卷 882-890页

作者： Xin kang Jiancong Liu Chungui Tian Dongxu Wang Yaorui Li hongyan Zhang Xusheng Cheng Aiping Wu Honggang Fu Key Laboratory of Functional Inorganic Material Chemistry Ministry of Education of the People’s Republic of ChinaHeilongjiang UniversityHarbin150080China College of Nuclear Science and Technology Harbin Engineering University145 Nantong StreetHarbin150001China

Size-controlled synthesis of two-dimensional(2D)catalysts with low stacking numbers and small nanoflake lengths is crucial for promoting the catalytic performance in diverse heterogeneous catalysis.Herein,we report a facile and general“surface curvature-confined synthesis”strategy to modulate the slab lengths and stacking numbers of 2D transition metal sulfides by controlling the strain induced by different surface curvature of supports.An efficient NiMo sulfide with shorter slab length(average 3.71 nm),less stacking number(1–2 layers)and more edge active sites is synthesized onto ZSM-5 zeolites with the average size of 100 nm,which shows superior kHDS value of dibenzothiophene(14.05×10^−7 mol/(g·s)),enhanced stability up to 80 h,and high direct desulfurization selectivity(>95%).This design concept is also proved to be generally applicable to modulate the slab lengths and stacking numbers of other 2D catalysts such as MoS2 and WS2 nanoflakes,which shows great potentials for developing more ultrasmall 2D catalysts with controlled sizes and excellent catalytic activities.

关键词： size-controlled synthesis ultrasmall two-dimensional(2D)catalysts zeolites surface curvature hydrodesulfurization

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低比转速离心压气机子午型线多目标优化设计

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内燃机工程 2023年第2期44卷 81-91页

作者：侯康田红艳佟鼎河北工业大学机械工程学院天津300401 中国北方发动机研究所柴油机增压技术重点实验室天津300400

以某前/尾缘组合掠型低比转速离心压气机叶轮为研究对象,选取叶轮子午流道型线控制点坐标作为优化变量,结合拉丁超立方试验设计方法构建样本数据库。通过样本数据的训练,建立探索优化变量与气动性能之间非线性关系的Kriging预测模型。... 详细信息

以某前/尾缘组合掠型低比转速离心压气机叶轮为研究对象,选取叶轮子午流道型线控制点坐标作为优化变量,结合拉丁超立方试验设计方法构建样本数据库。通过样本数据的训练,建立探索优化变量与气动性能之间非线性关系的Kriging预测模型。基于预测模型,采用SPEA–Ⅱ多目标优化算法进行多变量寻优,以实现设计工况和非设计工况下等熵效率最大化,并对叶轮流场进行整级计算和分析。优化结果表明:设计工况和非设计工况下,压气机等熵效率分别提高了2.69和0.45个百分点;整级压比在大流量工况有所提升,而在小流量工况略有降低;堵塞流量增大,稳定运行范围拓宽。从叶轮流场可以看出,优化后叶轮子午流道前段曲率减小,流道间隙泄漏和流动分离受到抑制;后端流道高度降低,流道扩压度减小,增加了出口处气流速度,低速流团的流动损失降低。

关键词：子午流道叶轮优化离心压气机多目标优化燃料电池

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NaV3O8 Nanosheets@Polypyrrole Core-Shell Composites with Good Electrochemical Performance as Cathode for Na-Ion Batteries

NaV3O8 Nanosheets@Polypyrrole Core-Shell Composites with Goo...

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2015年第十四届全国应用化学年会

作者： KANG Hongyan LIU Yongchang WANG Yijing JIAO Lifang Key Laboratory of Advanced Energy Materials Chemistry (MOE) Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) Nankai University

Novel NaVO nanosheets@polypyrrole core-shell composites have been successfully prepared for the first time via a chemical oxidative polymerization method. Based on the morphological and microstructural characterization, it was found that the polypyrrole(PPy) was uniformly wrapped on the surfaces of the NaVO nanosheets. When used as cathode for Na-ion batteries, the as-synthesized NaVO@10% PPy composite shows significantly improved cycling performance(with a discharge capacity of 99 m Ah g after 60 cycles at 80 m A g) and better rate capacity(with a discharge capacity of 63 m Ah g at a high current density of 640 m A g) than pristine NaVO nanosheets. The greatly enhanced performance benefits from the unique core-shell structure, where the PPy coating not only prevents the pulverization and aggregation of the lamellar NaVO nanosheets during cycling, which can improve the cycling stability, but also enhances the electrical conductivity of the composite, which can facilitate Na+ ion diffusion.

关键词： NaV3O8 nanosheets Polypyrrole Core-shell Na-ion batteries

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一种基于ECC的RFID双向认证协议设计

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计算机应用与软件 2012年第9期29卷 289-292页

作者：康鸿雁菏泽学院计算机与信息工程系山东菏泽274015

针对有些RFID认证协议存在的可扩展性和安全隐私保护的问题,提出一个基于椭圆曲线密码(ECC)的RFID双向认证协议。对该协议进行详细的描述,并分析其安全性。结果表明该协议具有可扩展性,能够抵抗跟踪、重放、假冒、中间人等攻击,具有良... 详细信息

针对有些RFID认证协议存在的可扩展性和安全隐私保护的问题,提出一个基于椭圆曲线密码(ECC)的RFID双向认证协议。对该协议进行详细的描述,并分析其安全性。结果表明该协议具有可扩展性,能够抵抗跟踪、重放、假冒、中间人等攻击,具有良好的前向安全性和能够实现服务器和标签的双向认证。该协议成本低、安全、可扩展,具有一定的实用性。

关键词：射频识别椭圆曲线密码安全协议双向认证隐私

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直接驱动H型平台鲁棒最优同步控制仿真研究

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系统仿真学报 2022年第3期34卷 527-535页

作者：王丽梅么红岩张康沈阳工业大学电气工程学院辽宁沈阳110870

针对永磁直线同步电机直接驱动的H型运动平台存在双轴耦合、参数摄动及外部扰动等不确定因素,影响系统的同步控制精度和鲁棒性的问题,提出了一种基于H型运动平台耦合动力学模型的鲁棒最优同步控制方法。基于Euler-Lagrange方程,建立双... 详细信息

针对永磁直线同步电机直接驱动的H型运动平台存在双轴耦合、参数摄动及外部扰动等不确定因素,影响系统的同步控制精度和鲁棒性的问题,提出了一种基于H型运动平台耦合动力学模型的鲁棒最优同步控制方法。基于Euler-Lagrange方程,建立双轴耦合动力学模型;设计交叉耦合同步控制器,有效地将单轴跟踪误差与双轴同步误差及其变化率结合起来;设计H∞鲁棒最优同步控制器来克服参数摄动及外部扰动等不确定因素的影响,增强系统的鲁棒性。通过仿真实验证明了该方法的有效性。

关键词：直驱H型平台永磁直线同步电动机交叉耦合控制混合误差鲁棒最优控制

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办公室档案管理工作的优化策略

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科技创新导报 2021年第2期18卷 114-116页

作者：康红岩吉林省人民医院吉林长春130021

档案室对各项工作以及日常经营状况记录信息的承载方式,是各企事业单位必不可少的基础性工作。办公室档案管理对于单位的正常运行至关重要。合理的档案管理工作,可在一定程度上保障企业运行的高效有序。在信息技术不断的发展下,促使办... 详细信息

档案室对各项工作以及日常经营状况记录信息的承载方式,是各企事业单位必不可少的基础性工作。办公室档案管理对于单位的正常运行至关重要。合理的档案管理工作,可在一定程度上保障企业运行的高效有序。在信息技术不断的发展下,促使办公室档案管理也在不断向信息化方向发展,而各种信息化档案管理系统也被应用在企事业单位中,极大地提升了档案管理效率及质量。但基于人为因素与客观条件等影响,导致部分企事业单位在档案管理上还存在着效率不足的问题,而本文也将以此作为方向,提出了办公室档案管理工作的优化路径。

关键词：办公室档案管理优化工作策略

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Endothelial glycocalyx mediated vascular remodeling induced by hemodynamic environmental alteration

Endothelial glycocalyx mediated vascular remodeling induced ...

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第十二届全国生物力学学术会议暨第十四届全国生物流变学学...

作者： hongyan kang Xiaoyan Deng Yubo Fan Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education School of Biological Science & Medical EngineeringBeihang University Beijing Advanced Innovation Centre for Biomedical Engineering Beihang University National Research Center for Rehabilitation Technical Aids

Objective Vascular remodeling induced by hemodynamic stimuli contributes to the physiological processes such as wound healing and pathophysiology such as atherosclerosis, hypertension, and postspaceflight orthostatic intolerance. The importance of the endothelial glycocalyx in mechanotransduction of flow induced shear stress has been investigated over the last decade by using cultured endothelial cells. However, its role in hemodynamic stimulated vascular remodeling has triggered little attention. In the present study, we focused on the

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