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Some basic aspects of polymer nanocomposites: A critical review

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Nano Materials Science 2019年第1期1卷 2-30页

作者： Shaoyun Fu zheng sun Pei Huang Yuanqing Li Ning Hu College of Aerospace Engineering Chongqing University

Polymer nanocomposites have been investigated for about three decades. To get deep insights into the modifying effects of various nanofillers on mechanical and physical properties of polymer nanocomposites, the three basic aspects of processing, characterization and properties are critically reviewed in this paper. Nanofillers can be classified into three major types of two-dimensional (2D) layered, one-dimensional (1D) fibrous and zerodimensional (0D) spherical ones and this review thus discusses in detail the processing, characterization and properties of the three types of polymer nanocomposites. It starts with an introduction of various nanoscale fillers such as two-dimensional (2D) nano-clay, graphene and MXene, one dimensional (1D) carbon nanofibers and nanotubes, zero dimensional (0D) silica nanoparticles and ZnO quantum dots as well as nanofiller-polymer interfaces. The processing of these polymer nanocomposites using different methods and the characterization of nanofillers and polymer nanocomposites using various techniques are described. Finally, the mechanical and physical properties of these polymer nanocomposites are discussed by considering the effects of nanofiller type, dispersion and contents;also, interface properties show significant effects on the mechanical properties of polymer nanocomposites and are discussed in some details.

关键词： Polymer nanocomposite Nanofiller Processing Characterization Mechanical and physical properties

PAA-capped GdF3 nanoplates as dual-mode MRI and CT contrast agents

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Science Bulletin 2015年第12期60卷 1092-1100,I0002页

作者： Xiao-Yu zheng Ling-Dong sun Tao zheng Hao Dong Yang Li Ye-FuWang Chun-Hua Yan Beijing National Laboratory for Molecular Sciences State Key Laboratory of Rare Earth Materials Chemistry and ApplicationsPKU-HKU Joint Laboratory in Rare Earth Materials andBioinorganic Chemistry College of Chemistry and Molecular Engineering Peking University Beijing 100871 China

Aiming at improving the sensitivity and accu- racy 9f diagnosis, the combination of magnetic resonance imaging （MRI） and X-ray computed tomography （CT） in a single probe is in urgent need. Here, we report the devel- opment of polyacrylic acid （PAA）-capped GdF3 nanoplates （NPs） as novel MRI and CT dual-mode contrast agents （CAs） with high longitudinal relaxivity （rl） and large X-ray attenuation coefficient. Uniform GdF3 rhombic NPs were fabricated by controlling reaction conditions and intro- ducing dopants. The average size of GdF3 NPs is （10.6 ：k 1.1） nm in long diagonal, （7.0 -t- 0.8） nm in short diagonal, and （4.2 -4- 1.2） nm in thickness. Ligand-exchange treat- ment was performed to render the NPs water-dispersible. The rl of PAA-capped GdF3 NPs （15.8 L/（mmol s）） is four times higher than that of clinically used Gd-DTPA. We suppose that the high r~ value originates from the con- struction of two-dimensional （2D） nanostructures, which endows nanocrystals with larger surface areas and longer rotational correlation time than those of sphere nanostruc- tures with the same volume. The CT contrast enhancement ability of PAA-capped GdF3 NPs was evaluated in com- parison with clinically used Iohexol. The above results suggest that the PAA-capped GdF3 NPs could serve as CAs for MRI and CT dual-mode imaging.

关键词： Nanoplates GdF3 Contrast agent MRI CT

Study on the reaction of 3-methyl-2-butenal and 3-methylbutanal with Cl atoms: kinetics and reaction mechanism

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Journal of Environmental Sciences 2022年第6期34卷 25-33页

作者： Bo Shi Weigang Wang Cici Fan Yuchan Zhang zheng sun Yanli Zeng Maofa Ge College of Chemistry and Material Sciences Hebei Normal UniversityShijiazhuang 050024China State Key Laboratory for Structural Chemistry of Unstable and Stable Species Beijing National Laboratory for Molecular Sciences(BNLMS)Institute of ChemistryChinese Academy of SciencesBeijing 100190China Lanfang Normal University Langfang 065000China National Demonstration Center for Experiment Chemistry Hebei Normal UniversityShijiazhuang 050024China Key Laboratory of Inorganic Nano-material of Hebei Province Shijiazhuang 050024China

The reaction of Cl atoms with two C5aldehydes(3-methyl-2-butenal and 3-methylbutanal)were investigated by proton-transfer-reaction mass spectrum(PTR-MS)using smog chamber at 298±1 K and 760 Torr.A relative rate method was used to determine the rate constants of the title reactions with m-xylene and trans-2-butene as reference compounds:(3.04±0.18)×10^(-10)and(2.07±0.14)×10^(-10)cm^(3)/(molecule·sec)for 3-methyl-2-butenal and 3-methylbutanal,***,the gas-phase products were also identified by PTR-MS,and the possible reaction mechanisms were proposed basing on the identified *** detected gas-phase products are similar for two C5aldehydes reactions,mainly including small molecules of aldehydes,ketones and chlorinated aldehyde *** atmospheric lifetimes(τ)calculated for 3-methyl-2-butenal(τ=7.0 hr,marine boundary layer(MBL))and 3-methylbutanal(τ=10.3 hr,MBL)according to the obtained rate *** results indicate that Cl atoms at MBL are competitive with OH radicals for the degradation contribution of C5aldehyde compounds.

关键词： Smog chamber Kinetic Reaction mechanism Cl atoms

视觉图像与三维点云融合的障碍物主动识别与距离感知研究

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机床与液压 2024年第16期52卷 80-86页

作者：孙峥林国成谢睿朱俊鹏周煜吴汪平许阔广东电网有限责任公司广州白云供电局广东广州550014

针对无人机配电线自动巡检及绝缘层涂覆维护过程中障碍物主动识别和距离感知的问题,提出视觉图像与三维点云相结合的障碍物识别方法。对图像进行增广预处理来丰富数据集,引入基于特征提取的深度学习进行模型训练,获取障碍物目标的类别... 详细信息

针对无人机配电线自动巡检及绝缘层涂覆维护过程中障碍物主动识别和距离感知的问题,提出视觉图像与三维点云相结合的障碍物识别方法。对图像进行增广预处理来丰富数据集,引入基于特征提取的深度学习进行模型训练,获取障碍物目标的类别和方位,结合三维点云信息得到目标的距离信息。实验结果表明:三维点云与视觉图像融合的障碍物主动识别与距离感知算法可以兼顾实时与精准测距的需求,提高了系统预警的精确度,最大识别误差为2.356%,有助于提高无人机及线缆涂覆机器人的障碍感知能力,保障作业安全。

关键词：障碍物主动识别和距离感知算法视觉图像三维点云融合算法目标检测

One-step scalable preparation of N-doped nanoporous carbon as a high-performance electrocatalyst for the oxygen reduction reaction

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Nano Research 2013年第4期6卷 293-301页

作者： Zhenyu Liu Guoxin Zhang Zhiyi Lu Xiuyan Jin zheng Chang Xiaoming sun State Key Laboratory of Chemical Resource Engineering P. O. Box 98 Beijing University of Chemical Technology Beijing 100029 China

N-doped porous carbon materials have been prepared by a simple one-step pyrolysis of ethylenediaminetetraacetic acid （EDTA） and melamine in the presence of KOH and Co（NO3）2·6H20. The combination of the high specific area （1,485 m2.g-l）, high nitrogen content （10.8%） and suitable graphitic degree results in catalysts exhibiting high activity （with onset and half-wave potentials of 0.88 and 0.79 V vs the reversible hydrogen electrode （RHE）, respectively） and four-electron selectivity for the oxygen reduction reaction （ORR） in alkaline medium---comparable to a commercial Pt/C catalyst, but far exceeding Pt/C in stability and durability. Owing to their superb ORR performance, low cost and facile preparation, the catalysts have great potential applications in fuel cells, metal-air batteries, and ORR-related electrochemical industries.

关键词： oxygen reductionreaction nitrogen-doping porous carbon

Synthesis and Structure of O-Ethyl S-Hydrogen Isoquinolin-1-ylcarbonothioimidate

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Chinese Journal of Structural Chemistry 2006年第5期25卷 604-608页

作者： YU Yun LIN Li-Rong YOU Jun HUANG Rong-Bin zheng Lan-sun Department of Chemistry Longyan College Longyan Fujian 364000 China Department of Chemistry Xiamen University Xiamen 361005 China State Key Laboratory for Physical Chemistry of Solid Surfaces Xiamen University Xiamen 361005 China

O-Ethyl S-hydrogen isoquinolin-l-ylcarbonothioimidate was synthesized and its structure was characterized by IR, MS, ^1H NMR, elemental analysis and single-crystal X-ray diffraction. The crystal belongs to monoclinic, space group P21/c with a = 10.9471（19）, b = 9.3968（17）, c = 10.6125（19） A, β = 100.761 （3）°, V = 1072.5（3） A^3, Z = 4, Dc = 1.439 g/cm^3, F（000） = 488 and μ = 0.279 mm^-1. A total of 7763 reflections were collected, of which 2090 were unique. The structure was refined to the final R = 0.0322 and wR = 0.0882 for 2016 observed reflections with Ⅰ 〉 2σ（Ⅰ）. The crystal structure shows that there are intramolecular N-H…S hydrogen bonds and π-π stacking interactions between adjacent molecules.

关键词： O-ethyl S-hydrogen isoquinolin-1-ylcarbonothioimidate synthesis crystal structure

Multi-timescale optimization scheduling of interconnected data centers based on model predictive control

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Frontiers in Energy 2024年第1期18卷 28-41页

作者： Xiao GUO Yanbo CHE Zhihao zheng Jiulong sun Energy Power Electrical Automation and Information EngineeringTianjin UniversityTianjin 300072China

With the promotion of“dual carbon”strategy,data center(DC)access to high-penetration renewable energy sources(RESs)has become a trend in the ***,the uncertainty of RES poses challenges to the safe and stable operation of DCs and power *** this paper,a multi-timescale optimal scheduling model is established for interconnected data centers(IDCs)based on model predictive control(MPC),including day-ahead optimization,intraday rolling optimization,and intraday real-time *** day-ahead optimization stage aims at the lowest operating cost,the rolling optimization stage aims at the lowest intraday economic cost,and the real-time correction aims at the lowest power fluctuation,eliminating the impact of prediction errors through coordinated multi-timescale *** simulation results show that the economic loss is reduced by 19.6%,and the power fluctuation is decreased by 15.23%.

关键词： model predictive control interconnected data center multi-timescale optimized scheduling distributed power supply/landscape uncertainty

Transfer film effects induced by 3D-printed polyether-ether-ketone with excellent tribological properties for joint prosthesis

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Bio-Design and Manufacturing 2024年第1期7卷 43-56页

作者： Yang Li Jibao zheng Changning sun Dichen Li State Key Laboratory for Manufacturing System Engineering School of Mechanical EngineeringXi’an Jiaotong UniversityXi’an 710054China National Medical Products Administration(NMPA)Key Laboratory for Research and Evaluation of Additive Manufacturing Medical Devices Xi’an Jiaotong UniversityXi’an 710054China

Based on the building principle of additive manufacturing,printing orientation mainly determines the tribological properties of joint *** this study,we created a polyether-ether-ketone(PEEK)joint prosthesis using fused filament fabrication and investigated the effects of printing orientation on its tribological properties using a pin-on-plate tribometer in 25% newborn calf *** ultrahigh molecular weight polyethylene transfer film is formed on the surface of PEEK due to the mechanical capture of wear debris by the 3D-printed groove morphology,which is significantly impacted by the printing orientation of *** the printing orientation was parallel to the sliding direction of friction,the number and size of the transfer film increased due to higher steady *** transfer film protected the matrix and reduced the friction coefficient and wear rate of friction pairs by 39.13%and 74.33%,***,our findings provide a novel perspective regarding the role of printing orientation in designing knee prostheses,facilitating its practical applications.

关键词： 3D printing orientation Transfer film Tribological properties Polyether-ether-ketone Knee prosthesis

碳纤维复合材料编织-针刺预制体成形质量研究

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高科技纤维与应用 2024年第3期49卷 34-43页

作者：周征西单忠德孙正郭子桐杨天政南京航空航天大学机电学院南京210016 南京航空航天大学航空航天结构力学及控制全国重点实验室南京210016

编织-针刺复合成形技术可实现大厚度回转形复合材料预制体一体化成形。为研究编织-针刺复合材料预制体成形质量,试制了不同K数纱线、编织角度的编织-针刺预制体以及作为对照组的机织-针刺预制体。考虑背面针刺纤维束形貌以及基布损伤提... 详细信息

编织-针刺复合成形技术可实现大厚度回转形复合材料预制体一体化成形。为研究编织-针刺复合材料预制体成形质量,试制了不同K数纱线、编织角度的编织-针刺预制体以及作为对照组的机织-针刺预制体。考虑背面针刺纤维束形貌以及基布损伤提出通过用预制体纤维束细长率χ_(f)定量表征针刺纤维束形貌。结合实际针刺预制体剥离曲线的变化特点,采用有效剥离曲线内所有波峰和波谷的平均值来对层间剥离强力进行描述。结果表明,试样纱线K数为6K时,编织-针刺预制体平均细长率相较机织-针刺预制体提升7.2%,编织-针刺预制体纤维束形貌更理想。当纱线K数由6增加至12时,机织-针刺预制体背面纤维束平均细长率提升了78.9%,编织-针刺预制体却减少了30.6%,其原因在于编织-针刺预制体刺针作用位置处纱线被挤开,增大了纤维束投影面积。编织-针刺预制体在层间剥离强力指标方面优势显著,各试样相较机织-针刺预制体提升38.0%以上,12K纱线编织-针刺预制体层间剥离强力比6K纱线大78.3%,且随着编织角由30°增加至60°,编织-针刺预制体平均剥离强力减少46.6%。

关键词：复合材料编织-针刺预制体成形质量预制体性能表征