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Dissolution-precipitation growth of uniform and clean two dimensional transition metal dichalcogenides

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National Science Review 2021年第3期8卷 108-116页

作者： zhengyang cai Yongjue Lai Shilong Zhao Rongjie Zhang Junyang Tan Simin Feng Jingyun Zou Lei Tang Junhao Lin Bilu Liu Hui-Ming Cheng Shenzhen Geim Graphene Center Tsinghua-Berkeley Shenzhen Institute and Tsinghua Shenzhen International Graduate SchoolTsinghua University Shenyang National Laboratory for Materials Sciences Institute of Metal ResearchChinese Academy of Sciences Department of Physics Southern University of Science and Technology

Two dimensional transition metal dichalcogenides(TMDCs) have attracted much interest and shown promise in many applications.However,it is challenging to obtain uniform TMDCs with clean surfaces,because of the difficulties in controlling the way the reactants are supplied to the reaction in the current chemical vapor deposition growth process.Here,we report a new growth approach called’dissolution-precipitation’(DP) growth,where the metal sources are sealed inside glass substrates to control their feeding to the reaction.Noteworthy,the diffusion of metal source inside glass to its surface provides a uniform metal source on the glass surface,and restricts the TMDC growth to only a surface reaction while eliminating unwanted gas-phase reaction.This feature gives rise to highly uniform monolayer TMDCs with a clean surface on centimeter-scale substrates.The DP growth works well for a large variety of TMDCs and their alloys,providing a solid foundation for the controlled growth of clean TMDCs by the fine control of the metal source.

关键词： dissolution-precipitation growth two dimensional materials transition metal dichalcogenides uniform clean

Porous nitrogen-doped carbon/MnO coaxial nanotubes as an efficient sulfur host for lithium sulfur batteries

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Nano Research 2019年第1期12卷 205-210页

作者： Chao Lin Longbing Qu Jiantao Li zhengyang cai Haoyun Liu Pan He Xu Xu Liqiang Mai State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyLuoshi Road 122Wuhan 430070China Department of Mechanical Engineering The University of MelbourneVictoria 3010Australia

As a promising candidate for next generation energy storage devices, lithium sulfur (Li-S) batteries still confrant rapid capacity degradation and low rate capability. Herein, we report a well-architected porous nitrogen-doped carbon/MnO coaxial nanotubes (MnO@PNC) as an efficient sulfur host material. The host shows excellent electron conductivity, sufficient ion transport channels and strong adsorption capability for the polysulfides, resulting from the abundant nitrogen-doped sites and pores as well as MnO in the carbon shell of MnO@PNC. The MnO@PNC-S composite electrode with a sulfur content of 75 wt.% deliveries a specific capacity of 802 mAh·g^-1 at a high rate of 5.0C and outstanding cycling stability with a capacity retention of 82% after 520 cycles at 1.0C.

关键词： nitrogen doping porous MnO carbon nanotubes sulfur batteries

Confined van der Waals Epitaxial Growth of Two-Dimensional Large Single-Crystal In_(2)Se_(3) for Flexible Broadband Photodetectors

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Research 2019年第1期2019卷 1096-1105页

作者： Lei Tang Changjiu Teng Yuting Luo Usman Khan Haiyang Pan zhengyang cai Yue Zhao Bilu Liu Hui-Ming Cheng Shenzhen Geim Graphene Center Tsinghua-Berkeley Shenzhen InstituteTsinghua UniversityShenzhen 518055China Shenzhen Institute for Quantum Science and Engineering and Department of Physics Southern University of Science and TechnologyShenzhen 518055China Shenzhen Key Laboratory of Quantum Science and Engineering Shenzhen 518055China Shenyang National Laboratory for Materials Sciences Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China

The controllable growth of two-dimensional(2D)semiconductors with large domain sizes and high quality is much needed in order to reduce the detrimental efect of grain boundaries on device performance but has proven to be challenging.Here,we analyze the precursor concentration on the substrate surface which signifcantly infuences nucleation density in a vapor deposition growth process and design a confned micro-reactor to grow 2D In_(2)Se_(3) with large domain sizes and high quality.Te uniqueness of this confned micro-reactor is that its size is∼102-103 times smaller than that of a conventional reactor.Such a remarkably small reactor causes a very low precursor concentration on the substrate surface,which reduces nucleation density and leads to the growth of 2D In_(2)Se_(3) grains with sizes larger than 200�m.Our experimental results show large domain sizes of the 2D In_(2)Se_(3) with high crystallinity.Te fexible broadband photodetectors based on the as-grown In_(2)Se_(3) show rise and decay times of 140 ms and 25 ms,efcient response(5.6 A/W),excellent detectivity(7×10^(10) Jones),high external quantum efciency(251%),good fexibility,and high stability.Tis study,in principle,provides an efective strategy for the controllable growth of high quality 2D materials with few grain boundaries.

关键词： stability grain sizes

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轴对称矢量喷管液压伺服系统设计与仿真研究

机床与液压 2024年第8期52卷 98-104页

作者：周翊农蔡开龙刘正扬王阿久熊鑫玉南昌航空大学飞行器工程学院江西南昌330063 南昌航空大学通航学院江西南昌330063

针对轴对称矢量喷管的功能要求,设计一种基于模糊PID控制的轴对称矢量喷管液压伺服系统。运用AMESim和MATLAB/Simulink对该系统进行建模与联合仿真,并与常规PID控制进行比较,分析系统的响应特点,验证电液伺服阀冗余备份功能和故障回中... 详细信息

针对轴对称矢量喷管的功能要求,设计一种基于模糊PID控制的轴对称矢量喷管液压伺服系统。运用AMESim和MATLAB/Simulink对该系统进行建模与联合仿真,并与常规PID控制进行比较,分析系统的响应特点,验证电液伺服阀冗余备份功能和故障回中功能的可行性。仿真结果表明:所设计的轴对称矢量喷管液压伺服系统具有良好的工作性能,而加入模糊PID控制的系统具有更好的稳态特性、动态特性和更强的鲁棒性,同时验证了电液伺服阀冗余备份功能和故障回中功能是切实可行的。

关键词：轴对称矢量喷管液压系统模糊PID AMESim/Simulink联合仿真

Mechanical behaviour of medium-grained sandstones exposed to differential cyclic loading with distinct loading and unloading rates

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第6期14卷 1849-1871页

作者： zhengyang Song Heinz Konietzky Yunfeng Wu Kun Du Xin cai Department of Civil Engineering School of Civil and Resource Engineering University of Science and Technology Beijing Geotechnical Institute TU Bergakademie Freiberg School of Resources and Safety Engineering Central South University

This work aims to investigate the mechanical behaviour of medium-grained sandstones under cyclic loading with different loading/unloading rates. This type of cyclic loading is called differential cyclic loading(DCL) and is considered for testing rock behaviour. In the experiments, constant amplitude and multi-level cyclic loadings were performed. Three loading modes were designed to consider different relationships between loading and unloading rates. Axial strain evolution and energy dissipation were analysed for different loading/unloading rates and maximum cyclic load level. The correlations between P-wave velocities and strengths of rocks deduced from this research are compared with existing published data. The relationships between final strength and axial strain at failure under different loading patterns were also discussed and a rough assessment of the remaining fatigue life is introduced using the predicted value by fitting the axial peak strain.

关键词： Differential cyclic loading (DCL) Rock fatigue Loading/unloading rate Energy dissipation Damage accumulation

Fretting Wear Characteristics of Nuclear Fuel Cladding in High-Temperature Pressurized Water

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Chinese Journal of Mechanical Engineering 2023年第4期36卷 326-338页

作者： Jun Wang Haojie Li zhengyang Li Yujie Lei Quanyao Ren Yongjun Jiao Zhenbing cai Key Lab of Advanced Technologies of Materials Tribology Research InstituteSouthwest Jiaotong UniversityChengdu 610031China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of ChinaChengdu 610213China

In pressurized water reactor(PWR),fretting wear is one of the main causes of fuel assembly failure.Moreover,the operation condition of cladding is complex and harsh.A unique fretting damage test equipment was developed and tested to simulate the fretting damage evolution process of cladding in the PWR environment.It can simulate the fretting wear experiment of PWR under different temperatures(maximum temperature is 350℃),displacement amplitude,vibration frequency,and normal force.The fretting wear behavior of Zr-4 alloy under different temperature environments was tested.In addition,the evolution of wear scar morphology,profile,and wear volume was studied using an optical microscope(OM),scanning electron microscopy(SEM),and a 3D white light interferometer.Results show that higher water temperature evidently decreased the cladding wear volume,the wear mechanism of Zr-4 cladding changed from abrasive wear to adhesive wear and the formation of an oxide layer on the wear scar reduced the wear volume and maximum wear depth.

关键词： Fretting wear Cladding High temperature and high pressure Zirconium alloy

基于PM2.5和CO2现场实时监测的大型展馆室外吸烟点优化设置研究

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环境与职业医学 2024年第6期41卷 673-680页

作者：孙晋闫晨曦赵卓慧谢臣晨龚正阳唐颢乐坤蕾承语芝殷竹琰袁静宜陈德蔡云飞复旦大学公共卫生学院环境卫生学教研室/国家卫生健康委员会卫生技术评估重点实验室/公共卫生安全教育部重点实验室上海市健康促进中心上海市环境监测中心

[背景]公共场所室外吸烟点的设置不当可能会增加人群二手烟的暴露风险。开展吸烟点及其周边空气污染和相关影响因素的研究，为优化吸烟点的设置方案提供参考。[目的]探索室外吸烟点吸烟人数、距离对周边空气污染扩散特征的影响，提出室... 详细信息

[背景]公共场所室外吸烟点的设置不当可能会增加人群二手烟的暴露风险。开展吸烟点及其周边空气污染和相关影响因素的研究，为优化吸烟点的设置方案提供参考。[目的]探索室外吸烟点吸烟人数、距离对周边空气污染扩散特征的影响，提出室外吸烟点优化设置的合理依据。[方法]以中国国际进口博览会（简称“进博会”）大型展馆为对象，随机选取会展一层（地面层）和二层（距地面16 m）室外吸烟点各一个，在同一方向距离吸烟点0、3、6和9 m处，使用经过校验的便携式空气质量监测仪实时监测会展期间连续5 d的细颗粒物(PM2.5)与二氧化碳（CO2）质量浓度（后简称为浓度），在0 m处使用气象监测仪器同步监测环境气象因素水平（风向、风速及气压等），并在两层各选一个空旷的室外大气背景采样点开展平行采样。同期双人同步记录每个吸烟点每分钟的吸烟人数。采用广义相加回归模型开展时间序列分析，调整温度、湿度、风速等混杂因素，评估吸烟点吸烟人数、离吸烟点距离与吸烟点周边空气PM2.5和CO2浓度的关系。[结果]会展一层和二层吸烟点每分钟吸烟人数的中位数是6人[四分位数范围（IQR）:3～9]和9人（IQR:6～13）。监测期间，两处绝大部分时间（85.9%）处于无风(风速<0.6 m·s-1)状态。吸烟点位（0 m处）空气PM2.5浓度最高[均值±标准差：（106±114）μg·m-3]，是大气背景浓度（25±7）μg·m-3的4.2倍，监测点PM2.5浓度随与吸烟点距离的增加而呈梯度下降，9 m处监测点PM2.5浓度[（35±22）μg·m-3]接近对照点（1.4倍）；CO2在0 m处监测点取得最大值[（628±23）μmol·mol-1]，其均值是大气背景浓度[（481±40）μmol·mol-1]的1.3倍，且距吸烟点0、3、6和9 m处监测点的CO2浓度未呈现梯度下降趋势。经多因素回归分析，结果显示，以吸烟点为参照，距离每增加3 m，周边PM2.5和CO2浓度分别下降24.6[95%置信区间（CI）:23.5～25.8]μg·m-3（23.2%）和54.1 （95%CI:53.1～55.1）μmol·mol-1（8.6%）。吸烟人数每增加一人，PM2.5和CO2浓度分别增加2.0 （95%CI:1.7～2.8）μg·m-3和1.0 （95%CI:0.7～1.2）μmol·mol-1。敏感性分析结果显示，无风状态下，PM2.5和CO2在吸烟点的聚积更明显，周边不同距离点的浓度变化特征总体保持不变。[结论]室外吸烟点可显著增加周围空气PM2.5的浓度和人群二手烟烟雾的暴露风险，但随距离的增加呈现明显的浓度下降。在无风或软风等扩散条件不良的情况下，室外吸烟点推荐设置在距离非吸烟区至少9 m或更远处。

关键词：中国国际进口博览会细颗粒物吸烟行为公共场所广义相加模型

High-frequency enhanced response based on Sb_(2)Te_(3)topological insulators

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Photonics Research 2022年第10期10卷 2302-2308页

作者： SHI ZHANG CHAOFAN SHI WEIWEI TANG LIBO ZHANG LI HAN CHENGSEN YANG zhengyang ZHANG JIAN WANG MIAO cai GUANHAI LI CHANGLONG LIU LIN WANG XIAOSHUANG CHEN WEI LU College of Physics and Optoelectronic Engineering Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China State Key Laboratory of Infrared Physics Shanghai Institute of Technical PhysicsChinese Academy of SciencesShanghai 200083China Shanghai Institute of Optics and Fine Mechanics Chinese Academy of SciencesShanghai 201800China Department of Optoelectronic Science and Engineering Donghua UniversityShanghai 201620China Terahertz Technology Innovation Research Institute Shanghai Key Laboratory of Modern Optical SystemUniversity of Shanghai for Science and TechnologyShanghai 200093China

Topological insulators represent a new quantum phase of matter with spin-polarized surface states that are protected from backscattering, exhibiting electronic responses to light, such as topological quantum phase transitions. However, the effects of high-frequency driving topological intrinsic systems have remained largely unexplored challenges experimentally for high-sensitivity terahertz detection. In this study, by integrating Sb2Te3 topological insulators with subwavelength metal antennas through micro-nano processing, a high-frequency terahertz detector with high sensitivity is proposed. The enhanced response originates from the asymmetric scattering of the surface electrons in the Sb_(2)Te_(3) flakes induced by the terahertz wave. The device displays room-temperature photodetection with a responsivity of 192 mA/W and equivalent noise power of less than 0.35 nW/Hz^(1/2) in the frequency range from 0.02 to 0.3 THz. These results pave the way for the exploitation of topological insulators for high-frequency operation in real-time imaging within long-wavelength optoelectronics.

关键词： scattering insulator quantum

高端装备智能制造价值链的生产自组织与协同管理:设计制造一体化协同研发实践

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管理世界 2023年第3期39卷 127-139页

作者：张强赵爽耀蔡正阳合肥工业大学管理学院、过程优化与智能决策教育部重点实验室

新一代信息技术环境下,高端装备制造企业正在积极寻求和推动产品研制过程实现全球更大范围的物理空间、社会空间和信息空间中的数据串联、信息融合、业务协同和价值活动整合。作为一种以数据与模型集成融合为核心的新型制造服务模式,智... 详细信息

新一代信息技术环境下,高端装备制造企业正在积极寻求和推动产品研制过程实现全球更大范围的物理空间、社会空间和信息空间中的数据串联、信息融合、业务协同和价值活动整合。作为一种以数据与模型集成融合为核心的新型制造服务模式,智能制造价值链成为数字化时代高端装备制造企业打造全新竞争优势的战略方向和核心途径。本文结合高端装备技术与管理深度融合的设计制造研发实践,探讨了高端装备设计制造一体化协同管理架构,从价值场景与工作场景两个维度揭示高端装备设计制造一体化协同流程的生成过程,分析了面向组织协同、资源协同、协同决策的生产自组织构建过程,为高端装备的协同创新和高质量研制提供理论方法支撑。

关键词：高端装备智能制造价值链生产自组织协同管理一体化协同研发