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Robust n-type doping of WSe2 enabled by controllable proton irradiation

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Nano Research 2023年第1期16卷 1220-1227页

作者： Haidong liang Yue Zheng Leyi Loh Zehua Hu qijie liang Cheng Han Michel Bosman Wei Chen Andrew A.Bettiol Centre for Ion Beam Applications(CIBA) Department of PhysicsNational University of SingaporeSingapore 117542Singapore International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology of Ministry of Education Institute of Microscale OptoelectronicsShenzhen UniversityShenzhen 518060China Department of Physics National University of SingaporeSingapore 117551Singapore Department of Materials Science and Engineering National University of SingaporeSingapore 117575Singapore Department of Chemistry National University of SingaporeSingapore 117543Singapore Division of Physics and Applied Physics School of Physical and Mathematical ScienceNanyang Technological UniversitySingapore 637371Singapore Songshan Lake Materials Laboratory Songshan Lake Mat LabDongguan 523808China National University of Singapore(Suzhou)Research Institute 377 Lin Quan StreetSuzhou Industrial ParkSuzhou 215123China

Two-dimensional(2D)transition metal dichalcogenides(TMDs)are considered to be promising building blocks for the next generation electronic and optoelectronic devices.Various doping schemes and work function engineering techniques have been explored to overcome the intrinsic performance limits of 2D TMDs.However,a reliable and long-time air stable doping scheme is still lacking in this field.In this work,we utilize keV ion beams of H2+to irradiate layered WSe2 crystals and obtain efficient n-type doping effect for all irradiated crystals within a fluence of 1×1014 protons·cm−2(1e14).Moreover,the irradiated WSe2 remains an n-type semiconductor even after it is exposed to ambient conditions for a year.Localized ion irradiation with a focused beam can directly pattern on the sample to make high performance homogenous p-n junction diodes.Raman and photoluminescence(PL)spectra demonstrate that the WSe2 crystal lattice stays intact after irradiation within 1e14.We attribute the reliable electrondoping to the significant increase in Se vacancies after the proton irradiation,which is confirmed by our scanning transmission electron microscope(STEM)results.Our work demonstrates a reliable and long-term air stable n-type doping scheme to realize high-performance electronic TMD devices,which is also suitable for further integration with other 2D devices.

关键词： WSe2 proton beam irradiation n-type doping long-time air stable Se vacancies

Oxygen-induced controllable p-type doping in 2D semiconductor transition metal dichalcogenides

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Nano Research 2020年第12期13卷 3439-3444页

作者： qijie liang Jian Gou Arramel Qian Zhang Wenjing Zhang Andrew Thye Shen Wee SZU-NUS Collaborative Innovation Center for Optoelectronic Science&Technology International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology of Ministry of EducationCollege of Optoelectronic EngineeringShenzhen UniversityShenzhen518060China Department of Physics National University of Singapore2 Science Drive 3Singapore117551Singapore Department of Materials Science and Engineering National University of SingaporeSingapore117574Singapore Centre for Advanced 2D Materials National University of SingaporeBlock S146 Science Drive 2Singapore117546Singapore

Exposure to oxygen alters the physical and chemical properties of two-dimensional(2D)transition metal dichalcogenides(TMDs).In particular,oxygen in the ambient may influence the device stability of 2D TMDs over time.Engineering the doping of 2D TMDs,especially hole doping is highly desirable towards their device function.Herein,controllable oxygen-induced p-type doping in a range of hexagonal(MoTe2,WSe2,MoSe2 and PtSe2)and pentagonal(PdSe2)2D TMDs are demonstrated.Scanning tunneling microscopy,electrical transport and X-ray photoelectron spectroscopy are used to probe the origin of oxygen-derived hole doping.Three mechanisms are postulated that contribute to the hole doping in 2D TMDs,namely charge transfer from absorbed oxygen molecules,surface oxides,and chalcogen atom substitution.This work provides insights into the doping effects of oxygen,enabling the engineering of 2D TMDs properties for nanoelectronic applications.

关键词： two-dimensional transition metal dichalcogenides oxygen induced doping oxygen substitution charge transfer

The enhanced performance of piezoelectric nanogenerator via suppressing screening effect with Au particles/ZnO nanoarrays Schottky junction

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Nano Research 2016年第2期9卷 372-379页

作者： Shengnan Lu Qingliang Liao Junjie Qi Shuo Liu Yichong Liu qijie liang Guangjie Zhang Yue Zhang State Key Laboratory for Advanced Metals and Materials School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China Key Laboratory of New Energy Materials and Technologies University of Science and Technology Beijing Beijing 100083 China

This paper describes a novel strategy to weaken the piezopotential screening effect by forming Schottky junctions on the ZnO surface through the introduction of Au particles onto the surface. With this approach, the piezoelectric-energyconversion performance was greatly enhanced. The output voltage and current density of the Au@ZnO nanoarray-based piezoelectric nanogenerator reached 2 V and 1 μA/cm^2, respectively, 10 times higher than the output of pristine ZnO nanoarray-based piezoelectric nanogenerators. We attribute this enhancement to dramatic suppression of the screening effect due to the decreased carrier concentration, as determined by scanning Kelvin probe microscope measurements and impedance analysis. The lowered capacitance of the Au@ZnO nanoarraybased piezoelectric nanogenerator also contributes to the improved output. This work provides a novel method to enhance the performance of piezoelectric nanogenerators and possibly extends to piezotronics and piezophototronics.

关键词： screening effect,piezopotential,Schottky junction,Au@ZnO nanoarrays,piezoelectric nanogenerator

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氧化玉米淀粉/明胶复合胶囊壳的制备与表征

食品与机械 2024年第5期40卷 188-193页

作者：谭心梁春艳邓松林陈启杰罗永清长沙理工大学化学化工学院湖南长沙410076 湖南工业职业技术学院机械工程学院湖南长沙410000 岳阳天添胶囊股份有限公司湖南岳阳414000

目的:采用改性淀粉与明胶共混制备胶囊壳,降低胶囊壳制备成本。方法:以玉米原淀粉为原料,采用15%用量的过氧化氢氧化制备氧化玉米淀粉,与明胶共混,分别通过流延法和浸渍法制备了氧化玉米淀粉/明胶复合胶囊膜和胶囊壳,并采用傅里叶变换... 详细信息

目的:采用改性淀粉与明胶共混制备胶囊壳,降低胶囊壳制备成本。方法:以玉米原淀粉为原料,采用15%用量的过氧化氢氧化制备氧化玉米淀粉,与明胶共混,分别通过流延法和浸渍法制备了氧化玉米淀粉/明胶复合胶囊膜和胶囊壳,并采用傅里叶变换红外光谱(FT-IR)、X射线衍射(XRD)、扫描电子显微镜(SEM)对其进行表征。结果:当氧化玉米淀粉与明胶质量比为5∶5,制备的氧化玉米淀粉/明胶复合胶囊壳的干燥失重在13.0%~15.0%,在蒸馏水和模拟人工胃液中的崩解时限在10 min以内,脆碎度不超过5粒。结论:采用氧化玉米淀粉与明胶共混制备的复合胶囊壳性能符合《中国药典》(2020)要求。

关键词：氧化玉米淀粉明胶胶囊壳制备表征

岭南山水之间的“两观三性”融合营造——广州国家版本馆

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世界建筑 2024年第5期 40-45页

作者：何镜堂张振辉梁玮健孙启杰中国工程院华南理工大学建筑设计研究院有限公司华南理工大学建筑设计研究院有限公司何镜堂建筑创作研究院华南理工大学建筑一所

中国国家版本馆项目是纳入国家“十四五”规划的重大文化传世工程。中华版本传世工程聚焦展示大国形象、坚定文化自信、赓续中华文脉、推动文明对话的功能定位。中国国家版本馆广州分馆设计团队运用“两观三性”建筑理论作为总体指导思... 详细信息

中国国家版本馆项目是纳入国家“十四五”规划的重大文化传世工程。中华版本传世工程聚焦展示大国形象、坚定文化自信、赓续中华文脉、推动文明对话的功能定位。中国国家版本馆广州分馆设计团队运用“两观三性”建筑理论作为总体指导思想,提出“中华典藏、岭南山水、时代新韵、文明灯塔”的总体设计构思,连贯打通规划与布局、建筑与空间、环境与景观、工法与细部、绿色生态智慧技术等多个设计维度,融合营造岭南山水之间的中华文化殿堂。

关键词： “两观三性”建筑理论广州国家版本馆岭南山水融合营造

On-going nitrification in chloraminated drinking water distribution system(DWDS) is conditioned by hydraulics and disinfection strategies

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Journal of Environmental Sciences 2020年第10期32卷 151-162页

作者： Yi Shi Akintunde Babatunde Bettina Bockelmann-Evans qijie Li liang Zhang National Engineering Laboratory for Cereal Fermentation Technology Jiangnan UniversityWuxi 214122China Discipline of Ciuil Engineering Cardiff University School of EngineeringThe ParadeCardiffCF243AAUK School of Civil Engineering University of LeedsLeedsLS29JTUK

Within the drinking water distribution system(DWDS)using chloramine as disinfectant,nitrification caused by nitrifying bacteria is increasingly becoming a concern as it poses a great challenge for maintaining water quality.To investigate efficient control strategies,operational conditions including hydraulic regimes and disinfectant scenarios were controlled within a flow cell experimental facility.Two test phases were conducted to investigate the effects on the extent of nitrification of three flow rates(Q=2,6,and 10 L/min)and four disinfection scenarios(total Cl2=1 mg/L,Cl2/NH3-N=3:1;total Cl2=1 mg/L,Cl2/NH3-N=5:1;total Cl2=5 mg/L,Cl2/NH3-N=3:1;and total Cl2=5 mg/L,Cl2/NH3-N=5:1).Physico-chemical parameters and nitrification indicators were monitored during the tests.The characteristics of biofilm extracellular polymetric substance(EPS)were evaluated after the experiment.The main results from the study indicate that nitrification is affected by hydraulic conditions and the process tends to be severe when the fluid flow transforms from laminar to turbulent(2300

关键词： Nitrification Drinking water distribution system(DWDS) Biofilm Hydraulics Disinfection

基于单细胞转录组测序分析骨关节炎软骨细胞分化的分子机制

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生物骨科材料与临床研究 2024年第1期21卷 1-6,13页

作者：徐文飞梅其杰明春玉段戡袁长深郭锦荣胡琪曾超梁晓辉广西中医药大学第一附属医院四肢骨伤科广西南宁530023 广西中医药大学附属瑞康医院老年病科广西南宁530011 湖南中医药大学第二附属医院创伤骨科湖南长沙410005

目的深度分析骨关节炎(osteoarthritis,OA)软骨细胞分化的单细胞转录组数据,探究其关键性靶基因及分子机制,为临床靶向治疗骨关节炎提供分子理论依据。方法从GEO数据库下载数据集(GSE104782),包含10个骨关节炎样本及1464个软骨单细胞测... 详细信息

目的深度分析骨关节炎(osteoarthritis,OA)软骨细胞分化的单细胞转录组数据,探究其关键性靶基因及分子机制,为临床靶向治疗骨关节炎提供分子理论依据。方法从GEO数据库下载数据集(GSE104782),包含10个骨关节炎样本及1464个软骨单细胞测序结果,运用R语言分析软骨细胞分化中关键Marker基因,并采用质控和数据过滤、PCA、TSNE、细胞轨迹、GO、KEGG信号通路及蛋白互助网络分析揭示软骨细胞分化机制。结果该数据集共包含基因17380种、20个主成分、9种细胞类型、1886个Marker基因及6种分化途径,其中软骨祖细胞为软骨最早分化细胞。GO分析涉及软骨发育、结缔组织发育等生物过程;涉及含胶原蛋白细胞外基质、内质网内腔等细胞组分;涉及肝素结合、糖胺聚糖结合等分子功能。KEGG通路分析涉及蛋白质消化吸收、ECM受体相互作用、人乳头瘤病毒感染、补体与凝血级联反应、PI3K-Akt信号通路等信号通路。运用Cytoscape 3.7.2软件获得5个关键Marker基因(COL1A1、COL2A1、VEGFA、COL1A2、DCN)。结论运用单细胞转录组测序发现骨关节炎软骨细胞共有6种分化途径及多种Marker基因的潜在特征,进一步从单细胞角度阐述骨关节炎的发病机制。

关键词：骨关节炎软骨细胞单细胞转录组测序分子机制

中小学生汉语考试(YCT)在美国的发展现状与对策研究

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首都师范大学学报（社会科学版） 2023年第1期 82-92页

作者：李启洁梁德惠首都师范大学国际文化学院首都师范大学语言治理研究中心

美国中文教育的低龄化和孔院在美国发展状况的改变给美国中小学生汉语考试(YCT)带来了机遇与挑战。研究显示:(1)YCT的目标用户是汉语沉浸式项目小学生、汉语外语教学项目初中生以及华裔儿童;(2)目前,YCT缺乏与当地外语标准的衔接、试题... 详细信息

美国中文教育的低龄化和孔院在美国发展状况的改变给美国中小学生汉语考试(YCT)带来了机遇与挑战。研究显示:(1)YCT的目标用户是汉语沉浸式项目小学生、汉语外语教学项目初中生以及华裔儿童;(2)目前,YCT缺乏与当地外语标准的衔接、试题偏重知识考查等问题制约了其发展;(3)未来YCT可通过与国际主流语言标准接轨、分技能测试模块化及核心大纲与拓展大纲互补设计等方法提高测试科学性,使YCT成为国际权威测评工具;(4)在推广上应强调课标与考试配套,并丰富成绩汇报的诊断功能和资讯功能。

关键词：中小学生汉语考试(YCT) 汉语学习低龄化国际中文教育语言能力标准

Soil fungi of three native tree species inhibit biomass production and shift biomass allocation of invasive Mikania micrantha Kunth

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Science Bulletin 2013年第7期58卷 757-765页

作者： GAO Lei ZAN qijie LI MingGuang GUO Qiang HU liang JIANG Lu ZHOU Sheng LIU HaiJun State Key Laboratory of Biocontrol Sun Yat-sen University Guangdong Key Laboratory of Plant Resources Shenzhen Wild Animal Rescue Center School of Life Sciences Shenzhen University Shenzhen Wildlife Protecting Administration 6. School of Geographical Science and Planning Sun Yat-sen University

Soil microbes contribute to native plant species successful resistance against invasive plant.Three native tree species,Heteropanax fragrans (HF),Cinnamomum burmanii (CB),and Macaranga tanarius (MT) were effective in controlling the notorious invasive vine Mikania micrantha (MM).Biomass production and allocation patterns (shoot/root biomass ratio (shoot/root)) are important indicators of MM climbing coverage and competitive light-capturing capacity.An investigation was conducted to test the role of soil microbes associated with the three native tree species to inhibit MM biomass production and shift MM shoot/root.Rhizosphere soils originating from preculture HF,CB,MT,and MM plots were collected separately for use as inocula.The inocula were mixed with sterilized river sand at a 1:9 (w/w) ratio to grow MM.The fungicide carbendazim (methyl benzimidazol-2-ylcarbamate) was applied to half the treatments to kill pathogenic soil fungi.Two nutrient levels were established based on the natural soil nutrient concentration from a field stand invaded by MM.MM were grown from seeds in a glasshouse,harvested 15 weeks after sowing,and separated into shoot and root portions.Results showed that under interaction of soil origin and nutrient levels,MM biomass production was unchanged,but biomass allocation patterns were significantly different.MM biomass production grown in the three native tree soils under two nutrient levels was similar or higher than MM biomass production in MM conspecific soil,indicating the absence of species-specific pathogens that inhibited MM biomass production in native tree soils.However,in both conspecific and tree soils,MM biomass production was significantly reduced in the presence of pathogenic soil fungi,i.e.MM experienced significant fungal inhibition,demonstrating the pathogenic soil fungi promoted native tree resistence to MM.MM exhibited decreased shoot biomass allocation when cultivated in native tree soil relative to MM conspecific soil under field stand nutrient level conditions.Reduced resou

关键词： biological control biotic resistance Cinnamomum burmanii Heteropanax fragrans invasion ecology Macaranga tanarius Mikania micrantha nutrient levels pathogenic fungi