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Mn single-atoms decorated CNT electrodes for high-performance supercapacitors

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Nano Research 2024年第5期17卷 4039-4046页

作者： Qian Rong Chao Yuwen yingkai liu Yuanrong liu Chunyang Wang Yang Wang Ding Zhang Zhen Wen Yunnan Key Laboratory of Opto-Electronic Information Technology Institute of Physics and Electronic InformationYunnan Normal UniversityKunming 650500China Faculty of Metallurgical and Energy Engineering Kunming University of Science and TechnologyKunming 650093China Department of Physics and Astronomy University of CaliforniaIrvineCA 92697USA School of Materials Science and Engineering National Institute for Advanced MaterialsSmart Sensing Interdisciplinary Science CenterNankai UniversityTianjin 300350China Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices Institute of Functional Nano and Soft Materials(FUNSOM)Soochow UniversitySuzhou 215123China

Developing highly robust and efficient electrode materials is of critical importance to promoting the energy density of current supercapacitors for ***,we report an efficient catalyst with monodispersed Mn single-atoms embedded in carbon nanotubes(Mn-CNTs)for enhancing the electrode performance of supercapacitors.A high specific capacitance(1523.6 F·g^(-1) at 1.0 A·g^(-1))can be achieved,which is about twice as high as the specific capacitance of the electrode material without the introduction of Mn ***,the asymmetric electrochemical capacitor created with Mn-CNT and activated carbon exhibits a high energy density of 180.8 Wh·kg^(-1) at a power density of 1.4 kW·kg^(-1),much higher than most reported *** study shows that the integration of Mn atoms into the CNT can enhance the charge transport capacity and the number of polar active sites of Mn-CNT and then facilitate chemical interactions between Mn-CNT and OH-.This work provides a novel strategy to enable high-energy storage in supercapacitors by introducing single-atoms into carbon nanotubes to improve electrodes’energy density and cycle life.

关键词： carbon nanotube(CNT) supercapacitor single-atoms power density energy density

High-response formamidine bromide lead hybrid cadmium sulfide photodetector

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Chinese Optics Letters 2024年第2期22卷 159-166页

作者：刘耀刘磊张锐峰杨伟业刘应开 Institute of Physics and Electronic Information Yunnan Normal UniversityKunming 650500China Yunnan Key Laboratory of Optoelectronic Information Technology Kunming 650500China Key Laboratory of Advanced Technique&Preparation for Renewable Energy Materials Ministry of EducationYunnan Normal UniversityKunming 650500China

Organic-inorganic hybrid perovskite formamidinium lead bromide nanosheet(FAPb Br_(3)NS)is regarded as a superior substance used to construct optoelectronic ***,its uncontrollable stability seriously affects its application in the field of *** this paper,FAPb Br_(3)is combined with cadmium sulfide nanobelt(Cd S NB)to construct a hybrid device that greatly improves the stability and performance of the *** response of the FAPb Br_(3)NS/Cd S NB detector under 490 nm light illumination reaches 5712 A/W,while the response of the FAPb Br_(3)photodetector under equivalent conditions is only 25.45 A/*** photocurrent of the FAPb Br_(3)NS/Cd S NB photodetector is nearly 80.25%of the initial device after exposure to air for 60 *** difference in electric field distribution between the single material device and the composite device is simulated by the finite-difference time-domain *** shows the advantages of composite devices in photoconductive gain and directly promotes the hybrid device *** paper presents a new possibility for high stability,fast response photodetectors.

关键词： organic-inorganic hybrid perovskite stability finite-difference time-domain photodetector

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可归责性与避险限度的规范性认定

甘肃政法大学学报 2024年第1期 70-87页

作者：刘颖恺北京大学法学院

刑法紧急避险的体系定位不可一概而论,划分阻却违法和阻却责任的二分说有其合理依据,正当化紧急避险的根据在于结合个人本位与社会本位的多元论.纯粹的法益衡量有其固有缺陷,提示了有限导入归责思想的空间.紧急避险中归责探讨的实质是... 详细信息

刑法紧急避险的体系定位不可一概而论,划分阻却违法和阻却责任的二分说有其合理依据,正当化紧急避险的根据在于结合个人本位与社会本位的多元论.纯粹的法益衡量有其固有缺陷,提示了有限导入归责思想的空间.紧急避险中归责探讨的实质是危险分配与承担的规范判断,将影响避险要件和限度的认定.避险过当的认定要求依次考虑危险转移的必要性、相当性和狭义法益衡量.避险人引发“对他危险化”“自己危险化”情形下的避险条件和限度有所不同.生命冲突紧急避险的正当化需要通过规范考量实现.强制程度的动态变化将影响强制避险中的归责认定.假想避险中紧迫现实危险要件的认定有其特殊性,认识错误的形成来源和程度将影响归责结论.

关键词：紧急避险可归责性危险分配必要性相当性

维普期刊数据库博看期刊

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高速列车粉末冶金闸片压坯裂纹成因与对策

金属材料与冶金工程 2024年第1期52卷 35-38,54页

作者：张瑞涛刘英凯刘家豪博深股份有限公司河北石家庄050035

压制成形是高速列车粉末冶金闸片生产工艺过程中的关键工序。压制生坯开裂是压制成形工序中导致产品质量不合格的主要因素,对高速列车粉末冶金闸片的产品质量有着重要影响。文中将自动压机压制高速列车粉末冶金闸片摩擦块生坯裂纹,按照... 详细信息

压制成形是高速列车粉末冶金闸片生产工艺过程中的关键工序。压制生坯开裂是压制成形工序中导致产品质量不合格的主要因素,对高速列车粉末冶金闸片的产品质量有着重要影响。文中将自动压机压制高速列车粉末冶金闸片摩擦块生坯裂纹,按照开裂纹位置和裂纹形态分为三类:过渡层与工作层之间的大裂纹(占比约20%)、过渡层与工作层之间的细裂纹(占比约50%)、工作层内细裂纹(占比约30%)。经过观察分析,得出了这三类裂纹产生的主要原因分别为:粉末成分偏析、工模具变形、布料不匀导致的坯体密度不均匀。对每一种裂纹形成原因制定了相应的措施,并对实施效果进行了阐述。

关键词：自动压机粉末冶金闸片摩擦块成形裂纹

PEG80F蜡粉对粉末冶金摩擦块工艺及产品性能的影响研究

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金属材料与冶金工程 2024年第4期52卷 17-20页

作者：张瑞涛刘英凯刘家豪博深股份有限公司河北石家庄050035

研究了PEG80F蜡粉作为粘结剂,对粉末冶金摩擦块压制摩擦块生坯强度、压制压力,烧结后摩擦块摩擦体剪切强度、摩擦性能的影响;同时研究了在工作环境下,存放时间对添加了PEG80F蜡粉的粉料及压制生坯的相关产品性能影响。结果表明:添加PEG... 详细信息

研究了PEG80F蜡粉作为粘结剂,对粉末冶金摩擦块压制摩擦块生坯强度、压制压力,烧结后摩擦块摩擦体剪切强度、摩擦性能的影响;同时研究了在工作环境下,存放时间对添加了PEG80F蜡粉的粉料及压制生坯的相关产品性能影响。结果表明:添加PEG80F蜡粉可以有效提高摩擦块压制生坯强度;添加量在一定范围内,随着PEG80F蜡粉添加量的增加,摩擦块摩擦系数逐渐降低,剪切强度逐渐升高;存放时间会对添加PEG80F蜡粉的粉料性能产生影响,建议粉料放置不超过3天,摩擦块生坯放置不超过7天;综合考虑添加PEG80F蜡粉对摩擦块生坯强度的提升效果及对生产工艺和产品性能的影响,建议PEG80F蜡粉添加量不超过2%。

关键词： PEG80F蜡粉粘结剂生坯强度摩擦系数

Computational exploration and screening of novel Janus MA2Z4 (M = Sc–Zn, Y–Ag, Hf–Au;A=Si, Ge;Z=N, P) monolayers and potential application as a photocatalyst

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Frontiers of physics 2022年第6期17卷 51-61页

作者： Weibin Zhang Woochul Yang yingkai liu Zhiyong liu Fuchun Zhang College of Physics and Electronics Information Yunnan Key Laboratory of Opto-Electronic Information TechnologyKey Laboratory of Advanced Technique&Preparation for Renewable Energy Materials-Ministry of EducationYunnan Normal UniversityKunming 650500China College of Physics and Electronic Information Yan’an UniversityYan’an 716000China Department of Physics Dongguk UniversitySeoul 04620Republic of Korea

By high-throughput calculations,13 thermally and environmentally stable Janus MA_(2)Z_(4) monolayers were screened from 104 types of *** 13 stable monolayers have very high charge carrier concentrations(×10^(15) cm^(–2)),which are better than those of the well-known graphene and TaS_(2).Because of their excellent conductivity,the 6 monolayers with band gaps less than 0.5 eV are identified as potential electrode materials for hydrogen evolution reaction *** potential applications as photoelectric or photocatalytic materials,bandgaps(Eg-HSE)higher than 0.5 eV remained,which resulted in 7 potential *** on optical absorption analysis in the visible-light range,H-HfSiGeP_(4) and HMoSiGeP_(4) have higher absorption ability and optical conductivity,which is quite impressive for optoelectronic,solar cell device,and photocatalysis ***,the transmittance coefficient of Janus MA_(2)Z_(4) monolayers is approximately 70%–80%in the visible-light range,which implies that these monolayers show good light *** potential applications as photocatalysts,the redox potential and charge effective mass analysis indicate that H-HfSiGeP_(4),HMoSiGeP_(4),T-ScSiGeN_(4),and T-ZrSiGeN_(4) are suitable photocatalysts for CO_(2) reduction *** high-throughput identification,13 types of new and stable Janus MA2Z4 monolayers were explored,and the basic properties and potential applications were investigated,which can reduce the time for experiments and provide basic data for the material genome initiative.

关键词： Janus MA2Z4 high-throughput identification charge carrier concentration electronic structure optical properties

不同粒度铜铬球磨粉对铜基摩擦材料性能的影响

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金属材料与冶金工程 2024年第4期52卷 3-6页

作者：郝文龙刘英凯周晓莹博深股份有限公司河北石家庄050035 河北省轨道交通车辆摩擦制动重点实验室河北石家庄050035

通过采用球磨方式制备了不同粒度的铜铬球磨粉,球磨时间分别为24、48、72 h。在摩擦材料中应用球磨粉,研究了铜铬球磨粉粒度不同,对摩擦材料力学性能及摩擦性能产生的影响。结果表明:随着球磨粉的球磨时间增长,球磨粉粒度逐渐降低,最大... 详细信息

通过采用球磨方式制备了不同粒度的铜铬球磨粉,球磨时间分别为24、48、72 h。在摩擦材料中应用球磨粉,研究了铜铬球磨粉粒度不同,对摩擦材料力学性能及摩擦性能产生的影响。结果表明:随着球磨粉的球磨时间增长,球磨粉粒度逐渐降低,最大粒径由124.1μm降至87.4μm;摩擦材料的力学性能随着球磨粉粒度的降低而提升,其中剪切强度由13.5 MPa升至16.0 MPa,抗压强度由78.1 MPa升至91.6 MPa;在初速度120 km/h摩擦制动时,随着铜铬球磨粉的粒度降低,摩擦材料的平均摩擦系数提高,由0.304提高至0.389,同时摩擦材料的磨耗量增大,由3.35 g增大至3.68 g。

关键词：机械合金化摩擦材料剪切强度磨耗量

Experimental and numerical study on ignition and combustion characteristics of boron-magnesium composite powders

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Particuology 2024年第1期84卷 12-29页

作者： Shuyuan liu Luyang Han Hongmei liu yingkai Song Linlin liu Songqi Hu Science and Technology on Combustion Internal Flow and Thermo-Structure LaboratoryNorthwestern Polytechnical UniversityXi'an710072China School of Mechanical Engineering and Rail Transit Changzhou UniversityChangzhou213164China Shanghai Institute of Space Propulsion Shanghai201112China Shanghai Engineering Research Center of Space Engine Shanghai201112China

A high-pressure laser ignition and combustion system with adjustable oxidizer gas atmosphere is established to investigate the ignition and combustion characteristics of boron-magnesium(BM)com-posite *** ignition and combustion model of BM powders is established and validated in the present *** results show that increasing water content,O_(2) content and Mg content all result in shorter ignition delay time of BM powders,among which the effect of water content is the most ***,ignition delay time increases as pressure *** combustion time decreases with increasing Mg content and ambient pressure but increases with water *** the increase of O_(2) content,combustion time of BM powders first increases and then decreases,which means a critical O_(2) content exists above which combustion time *** results show that there exists a trade-off between ignition and combustion performance of BM composite powders.

关键词： Boron magnesium powder Laser ignition Ignition and combustion model Reaction mechanism Numerical model

Enhanced optoelectronic characteristics of MoS_(2)-based photodetectors through hybridization with CdS_(0.42)Se_(0.58)nanobelt

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Journal of Advanced Dielectrics 2023年第6期13卷 20-28页

作者： Aimin liu Jiyu Zhao Qiuhong Tan Peizhi Yang yingkai liu Qianjin Wang College of Physics and Electronic Information Yunnan Normal University Yunnan Kunming 650500P.R.China Yunnan Provincial Key Laboratory for Photoelectric Information Technology Yunnan Normal University Yunnan Kunming 650500P.R.China Key Laboratory of Advanced Technique&Preparation for Renewable Energy Materials Ministry of Education Yunnan Normal University Yunnan Kunming 650500 P.R.China

Monolayer molybdenum disulfide(MoS_(2))has weak light absorption due to its atomically-thin thickness,thus hindering the development of MoS_(2)-based optoelectronic ***_(x)Se_(1-x)has excellent photoelectric performance in the visible light range,and its nanostructure shows great potential in new nanoscale electronic and optoelectronic *** this work,a composite photodetector device with the combination of monolayer MoS_(2)nanosheets and CdS_(0.42)Se_(0.58)nanobelts has been successfully prepared,which can not only maintain the inherent excellent properties of the two blocks,but also play a synergistic role between them,thus improving the photoelectric performance of the *** monolayer MoS_(2)nanosheet/CdS_(0.42)Se_(0.58)nanobelt photodetector has a wide spectral response range(400–800 nm),high responsivity(527.22 A/W)and large external quantum efficiency(EQE)(1.06×10^(5)%).Compared with the isolated monolayer MoS_(2)nanosheet,both the responsivity and EQE of the hybrid photodetector are increased by 117.4 times under 620 nm *** study provides a way to prepare hybrid photodetectors with wide spectral response and high responsivity.

关键词： Monolayer MoS_(2) CdS_(0.42)Se_(0.58)nanobelt photodetectors