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探索Bi_(2)SeO_(5)的高介电性能:从块体到双层和单层

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Science China Materials 2024年第3期67卷 906-913页

作者：董欣月何育彧管乐祝元昊吴金雄付会霞颜丙海 Tianjin Key Lab for Rare Earth Materials and Applications Center for Rare Earth and Inorganic Functional MaterialsSmart Sensor Interdisciplinary Science CenterSchool of Materials Science and EngineeringNankai UniversityTianjin 300350China Center of Quantum Materials and Devices College of PhysicsChongqing UniversityChongqing 401331China Chongqing Key Laboratory for Strongly Coupled Physics Chongqing UniversityChongqing 401331China Department of Condensed Matter Physics Weizmann Institute of ScienceRehovot 7610001Israel

Bi_(2)SeO_(5)是一种具有优异电绝缘性能的范德华(vdW)层状介电材料,引起了极大关注.然而,目前关于Bi_(2)SeO_(5)的研究主要停留在实验层面,仍然缺乏对其原子级薄膜的介电性能的相关理论认识.本文通过第一性原理计算确定了Bi_(2)SeO_(5... 详细信息

Bi_(2)SeO_(5)是一种具有优异电绝缘性能的范德华(vdW)层状介电材料,引起了极大关注.然而,目前关于Bi_(2)SeO_(5)的研究主要停留在实验层面,仍然缺乏对其原子级薄膜的介电性能的相关理论认识.本文通过第一性原理计算确定了Bi_(2)SeO_(5)的介电性能,发现其块体、双层和单层均具有超高平均介电常数(εr>20).研究表明,单层Bi_(2)SeO_(5)与双层Bi_(2)O_(2)Se之间的导带和价带能量偏移量均大于1 eV,表明单层Bi_(2)SeO_(5)依然可作为原子薄Bi_(2)O_(2)Se的良好介电层.此外,不同于h-BN或其他2D vdW绝缘体,Bi_(2)SeO_(5)的εr由其离子部分主导,且随着厚度的减小几乎保持不变.计算发现,单层Bi_(2)SeO_(5)的等效氧化层厚度可薄至0.3 n m,且单层Bi_(2)SeO_(5)在拉伸或压缩应变达到6%时均能保持高介电常数,这极大地促进了它与各种二维半导体的集成.本工作证明单层Bi_(2)SeO_(5)可以作为高性能二维电子器件良好的封装和介电层.

关键词： Bi_(2)SeO_(5) high-κ equivalent oxide thickness dielectric constant van der Waals first-principles calculations

薰衣草蒸馏废渣/环氧树脂复合材料的制备及力学性能

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工程塑料应用 2024年第2期52卷 51-56页

作者：马扶宸杜涛刘伟樊东焱钱大益武晋雄张会良宋剑斌伊犁师范大学化学化工学院新疆伊宁835000 新疆维吾尔自治区生物质资源清洁转化与高值利用重点实验室新疆伊宁835000 中国科学院长春应用化学研究所中国科学院生态环境高分子材料重点实验室长春130022

为了实现薰衣草蒸馏废渣资源利用,将薰衣草蒸馏废渣与环氧树脂复合,通过模压工艺制备薰衣草蒸馏废渣/环氧树脂复合材料,通过傅里叶变换红外光谱(FTIR)、万能力学试验机和扫描电子显微镜(SEM)等对复合材料的力学性能、形态结构和吸水率... 详细信息

为了实现薰衣草蒸馏废渣资源利用,将薰衣草蒸馏废渣与环氧树脂复合,通过模压工艺制备薰衣草蒸馏废渣/环氧树脂复合材料,通过傅里叶变换红外光谱(FTIR)、万能力学试验机和扫描电子显微镜(SEM)等对复合材料的力学性能、形态结构和吸水率等进行分析。结果表明,随着薰衣草蒸馏废渣含量的增加,复合材料的力学性能呈先增大后减小的趋势;在薰衣草蒸馏废渣质量分数为60%时复合材料具有最优异的冲击强度(1.56 kJ/m^(2))和弯曲强度(40.1MPa);在此含量基础上,采用氢氧化钠处理薰衣草蒸馏废渣,结果表明,所获得的环氧树脂复合材料的冲击强度和弯曲强度分别达到了3.04 kJ/m^(2)和66.2 MPa,较未处理时增加了94.9%和65%。FTIR分析结果表明,碱处理可以消除薰衣草蒸馏废渣表面的脂类等物质,改善了其与环氧树脂的界面性能;SEM结果证实,经碱处理后的复合材料内部有大量丝状物产生;吸水率结果表明,复合材料的吸水率随薰衣草蒸馏废渣含量的增加而增大,且经过碱处理后,复合材料具有较高的吸水率。

关键词：薰衣草环氧树脂力学性能碱处理

Development of a multi-view and geo-event-driven real-time collaborative GIS

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International Journal of Digital Earth 2022年第1期15卷 134-147页

作者： Sun Yaqin Xu Chen wu jinxiong Yuan Hang Shi Haibo Zhan Xiumei Zhang Lin Key Laboratory of Land Environment and Disaster Monitoring MNR China University of Mining and TechnologyXuzhouPeople’s Republic of China College of Surveying and GeoInformatics Tongji UniversityShanghaiPeople’s Republic of China

Supporting distributed real-time collaborative work has become an important development trend in *** enables group users to cooperate and improve the use of scientific data and collaboration ***-time collaborative GIS(RCGIS)provides a platform for supporting synchronous collaboration using geospatial data in various *** RCGIS generally works on a single map view,which has the disadvantage of collaborative interface *** traditional system-driven mechanism of RCGIS is a computer-interaction event that has the disadvantage of an unfriendly collaborative *** paper presents a design and prototype of a RCGIS based on multi-view and geo-event driven *** geo-event-driven mechanism provides users with a smoother collaborative perception and interactions that are more natural and *** collaboration process for a GIS that is driven by geo-events is also discussed.A multi-view technique is used to make real-time GIS collaboration more *** paper also proposes a synchronization strategy for public–private ***,walk-through examples are used to demonstrate the use of RCGIS within a web environment.

关键词： Geographical information collaboration real-time multi-view geo-event driven

Near room-temperature ferromagnetism in air-stable twodimensional Cr_(1−x)Te grown by chemical vapor deposition

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Nano Research 2022年第4期15卷 3763-3769页

作者： Zhansheng Gao Ming Tang Junwei Huang Jiabiao Chen Wei Ai Linglu wu Xinyue Dong Yifei Ma Zheshan Zhang Lei Zhang Yaping Du Huixia Fu Hongtao Yuan jinxiong wu Feng Luo Tianjin Key Lab for Rare Earth Materials and Applications Center for Rare Earth and Inorganic Functional MaterialsSchool of Materials Science and EngineeringNankai UniversityTianjin 300350China National Laboratory of Solid State Microstructures College of Engineering and Applied SciencesNanjing UniversityNanjing 210093China Center of Quantum Materials and Devices&College of Physics Chongqing UniversityChongqing 401331China Beijing National Laboratory for Molecular Sciences Beijing 100871China

Identifying air-stable two-dimensional(2D)ferromagnetism with high Curie temperature(T_(c))is highly desirable for its potential applications in next-generation ***,most of the work reported so far mainly focuses on promoting one specific key factor of 2D ferromagnetism(T_(c)or air stability),rather than comprehensive promotion of both of ***,ultrathin Cr_(1-x)Te crystals grown by chemical vapor deposition(CVD)show thickness-dependent T_(c)up to 285 *** out-of-plane ferromagnetic order is well preserved down to atomically thin limit(2.0 nm),as evidenced by anomalous Hall effect observed in non-encapsulated ***,the CVD-grown Cr_(1-x)Te nanosheets present excellent ambient stability,with no apparent change in surface roughness or electrical transport properties after exposure to air for *** work provides an alternative platform for investigation of intrinsic 2D ferromagnetism and development of innovative spintronic devices.

关键词： Cr1-xTe room-temperature ferromagnetism air stability anomalous Hall effect chemical vapor deposition

Temperature-driven reversible structural transformation and conductivity switching in ultrathin Cu_(9)S_(5)crystals

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Nano Research 2023年第7期16卷 10515-10521页

作者： Lei Zhang Zeya Li Ying Deng Li Li Zhansheng Gao Jiabiao Chen Zhengyang Zhou Junwei Huang Weigao Xu Xuewen Fu Hongtao Yuan Feng Luo jinxiong wu Tianjin Key Lab for Rare Earth Materials and Applications Center for Rare Earth and Inorganic Functional MaterialsSmart Sensor Interdisciplinary Science CenterSchool of Materials Science and EngineeringNankai UniversityTianjin 300350China National Laboratory of Solid State Microstructures Jiangsu Key Laboratory of Artificial Functional MaterialsCollege of Engineering and Applied Sciencesand Collaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210093China Ultrafast Electron Microscopy Laboratory The Ministry of Education(MOE)Key Laboratory of Weak-Light Nonlinear PhotonicsSchool of PhysicsNankai UniversityTianjin 300071China School of Chemistry and Chemical Engineering Nanjing UniversityNanjing 210093China Shanghai Institute of Ceramics Chinese Academy of SciencesShanghai 200093China

Two-dimensional(2D)materials with reversible phase transformation are appealing for their rich physics and potential applications in information ***,up to now,reversible phase transitions in 2D materials that can be driven by facile nondestructive methods,such as temperature,are still ***,we introduce ultrathin Cu_(9)S_(5)crystals grown by chemical vapor deposition(CVD)as an exemplary *** the first time,their basic electrical properties were investigated based on Hall measurements,showing a record high hole carrier density of~1022 cm^(-3) among 2D ***,an unusual and repeatable conductivity switching behavior at~250 K were readily observed in a wide thickness range of CVD-grown Cu_(9)S_(5)(down to 2 unit-cells).Confirmed by in-situ selected area electron diffraction,this unusual behavior can be ascribed to the reversible structural phase transition between the room-temperature hexagonalβphase and low-temperatureβ’phase with a *** work provides new insights to understand the physical properties of ultrathin Cu_(9)S_(5)crystals,and brings new blood to the 2D materials family with reversible phase transitions.

关键词： ultrathin Cu_(9)S_(5)crystals ultrahigh carrier density reversible phase transition conductivity switching chemical vapor deposition

Investigation of black phosphorus as a nano-optical polarization element by polarized Raman spectroscopy

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Nano Research 2018年第6期11卷 3154-3163页

作者： Nannan Mao Shishu Zhang jinxiong wu Huihui Tian Juanxia wu Hua Xu Hailin Peng Lianming Tong Jin Zhang Center for Nanochemistry Beijing National Laboratory for Molecular Sciences Key Laboratory for the Physics and Chemistry of Nanodevices State Key Laboratory for Structural Chemistry of Unstable and Stable Species College of Chemistry and Molecular Engineering Peking University Beijing 100871 China School of Materials Science and Engineering Shaanxi Normal University Ki'an 770062 China

Manipulating the polarization of light at the nanoscale is essential for the development of nano-optical devices. Owing to its corrugated honeycomb structure, two-dimensional （2D） layered black phosphorus （BP） exhibits outstanding in-plane optical anisotropy with distinct linear dichroism and optical birefringence in the visible region, which are superior characteristics for ultrathin polarizing optics. Herein, taking advantage of polarized Raman spectroscopy, we demonstrate that layered BP with a nanometer thickness can remarkably alter the polarization state of a linearly-polarized laser and behave as an ultrathin optical polarization element in a BP-Bi2Se3 stacking structure by inducing the exceptionally polarized Raman scattering of isotropic Bi2Se3. Our findings provide a promising alternative for designing novel polarization optics based on 2D anisotropic materials, which can be easily integrated in micro- sized all-optical and optoelectronic devices.

关键词： black phosphorus polarizing optics linear dichroism birefringence two-dimensional layered crystals

Exploitation of Bi2O2Se/graphene van der Waals heterojunction for creating efficient photodetectors and short-channel field-effect transistors

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InfoMat 2019年第3期1卷 390-395页

作者： Congwei Tan Shipu Xu Zhenjun Tan Luzhao Sun jinxiong wu Tianran Li Hailin Peng Center for Nanochemistry Beijing Science and Engineering Center for NanocarbonsBeijing National Laboratory for Molecular SciencesInstitute of Physical ChemistryCollege of Chemistry and Molecular EngineeringPeking UniversityBeijingChina Academy for Advanced Interdisciplinary Studies Peking UniversityBeijingP.R.China

The formation of heterojunction within solid-state devices enables them with eventually high performances,but provides a challenge for material synthesis and device fabrication because strict conditions such as lattice match are ***,we show a facile method to fabricate a van der Waals(vdW)heterojunction between two-dimensional(2D)bismuth oxyselenide(Bi2O2Se)and graphene,during which the graphene is directly transferred to the Bi2O2Se and served as a lowcontract-resistant electrode with small work function mismatch(~50 meV).As an optoelectronic device,the Bi2O2Se/graphene vdW heterojunction allows for the efficient sensing toward 1200-nm incident *** the application of fieldeffect transistors(FETs),the short-channel(50 nm)sample can be synthesized by utilizing these two 2D materials(ie,channel:Bi2O2Se;drain/source terminal:graphene)and the n-type characteristic can be observed with the accordant field *** is confirmed that we show a simple way to prepare the vdW heterojunction which is aiming to the high-performance applications among optoelectronics and FETs.

关键词： Bi2O2Se graphene van der Waals heterojunctions

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粤诗人传记的撰述与汇编

图书馆论坛 2019年第2期39卷 102-109页

作者：吴劲雄中山大学中文系

历代广东诗人传记是科研工作者进行广东文史研究的必备资料。但是,由于馆藏分散、传记来源不确定、查找地太远、阅读有限制、没有索引可供检索等,造成研究者无法如愿地找到想用之书和读到想查之传。因此,把散布在全国各大图书馆、研究... 详细信息

历代广东诗人传记是科研工作者进行广东文史研究的必备资料。但是,由于馆藏分散、传记来源不确定、查找地太远、阅读有限制、没有索引可供检索等,造成研究者无法如愿地找到想用之书和读到想查之传。因此,把散布在全国各大图书馆、研究机构、博物馆、高等院校及私人藏家的资源全部汇集在一起,顺应时代需求进行全新的编排,并编制完善的姓名字号索引,以影印的保真方式出版,将给各地方、各领域、各专业人士的研究工作带来极大的便利。

关键词：广东诗人传记汇编

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低硅体系下SAPO-34分子筛的合成

石油化工 2012年第5期41卷 510-514页

作者：吴金雄李牛项寿鹤南开大学化学学院先进能源材料教育部重点实验室天津300071

以三乙胺和吗啉为模板剂,考察了硅含量和晶化温度对合成SAPO-34分子筛的影响,研究了低硅条件下SAPO-34分子筛的晶化规律。在n(SiO2)∶n(Al2O3)=0.1的低硅体系中合成出了高结晶度的SAPO-34分子筛,发现将晶化温度从200℃降至170℃更有利... 详细信息

以三乙胺和吗啉为模板剂,考察了硅含量和晶化温度对合成SAPO-34分子筛的影响,研究了低硅条件下SAPO-34分子筛的晶化规律。在n(SiO2)∶n(Al2O3)=0.1的低硅体系中合成出了高结晶度的SAPO-34分子筛,发现将晶化温度从200℃降至170℃更有利于低硅条件下SAPO-34分子筛的合成。根据合成结果初步认为,低硅条件下SAPO-34分子筛的合成可能符合低温成核、高温生长机理,并用分段晶化实验加以证实。实验结果表明,在低硅体系下,先在170℃晶化一段时间再在200℃晶化一段时间(总晶化时间48 h),不仅可获得高结晶度SAPO-34分子筛,且能缩短晶化时间;若将分段晶化温度顺序调换,即先在200℃晶化再在170℃晶化,则无法获得纯相SAPO-34分子筛,说明先低温后高温的分段晶化更有利于低硅体系下纯相SAPO-34分子筛的合成。

关键词：低硅体系 SAPO-34分子筛分段晶化甲醇制烯烃催化剂