摘要：
采用分子动力学方法分别对管内充以铝原子碳纳米管(CNT)与氮化硼纳米管(BNNT)进行了结构性能研究.优化结果显示:(5,5)CNT和BNNT内均能形成一束一维铝纳米线(AlNW);(10,10)管内形成的是多束AlNW,其中(10,10)CNT内形成的是11束高度轴对称一维AlNW,而(10,10)BNNT内形成的是5束螺旋结构形状的AlNW.进一步分析表明:CNT内的AlNW具有比BNNT内的AlNW较大的原子分布线密度,但大管径(10,10)型BNNT内的螺旋状AlNW可以具有比相同管径CNT内纳米线更高的结晶性.通过对其轴向压缩模拟及其能量分析,可以发现AlNW@CNT复合结构的屈曲应变明显大于AlNW@BNNT,且同类型复合结构,屈曲应变随管径增大而减小,故较小管径的AlNW@CNT具有更强轴向抗压能力.能量分析结果表明van der Waals能是维系复合纳米管结构稳定,增大抗压能力的主要原因.
作者机构：
[Yuan, J. H.; Luo, A. Y.; Zhang, H. L.; Fan, Z. Q.; Zhang, Z. H.; Hu, R.; Yang, C. H.] Changsha Univ Sci & Technol, Inst Nanomat & Nanostruct, Changsha 410114, Hunan, Peoples R China.
通讯机构：
[Zhang, Z. H.] C;Changsha Univ Sci & Technol, Inst Nanomat & Nanostruct, Changsha 410114, Hunan, Peoples R China.
关键词：
Carrier mobility;Electronic structure;Hetero-atom atom doping;I-V characteristics;Phagraphene nanoribbons
摘要：
Phagraphene, a new carbon allotrope, was proposed recently. We here select a mixed-edge phagraphene ribbon to study B-, N-, and BN-doping effects respectively on the geometric stability, electronic structure, carrier mobility, and device property. Calculations show that the energetic and thermal stability for these ribbons are very high. With different doping types and doping sites, the bandgap size of a ribbon may be nearly unchanged, increased, or decreased as compared with the intrinsic ribbon, and even become a metal, thus presenting fully tunable electronic structures. For this, the charge transfer shifting edge bands and the new formed hybridized bands due to doping play a crucial role. More interestingly, doping at different positions can regulate the carrier mobility of ribbon, and the difference of two orders of magnitude for hole mobility can be generated by BN-doping. In addition, the study on device property shows that there is a prominent negative differential resistance characteristics occurring in a BN-doped ribbon device. These findings are meaningful for understanding the doping effects on electronic properties of phagraphene nanoribbons. (C) 2017 Elsevier B.V. All rights reserved.
期刊：
Current Nanoscience,2016年12(5):636-644 ISSN：1573-4137
通讯作者：
Liew, K. M.
作者机构：
[Yuan, Jianhui] Changsha Univ Sci & Technol, Sch Phys & Elect Sci, Changsha 410114, Hunan, Peoples R China.;[Yuan, Jianhui; Liew, K. M.] City Univ Hong Kong, Shenzhen Res Inst Bldg, Shenzhen Hitech Ind Pk, Shenzhen, Peoples R China.;[Zhang, L. W.] Shanghai Ocean Univ, Coll Informat Sci & Technol, Shanghai 201306, Peoples R China.;[Liew, K. M.] City Univ Hong Kong, Dept Architecture & Civil Engn, Kowloon, Hong Kong, Peoples R China.
通讯机构：
[Liew, K. M.] C;City Univ Hong Kong, Dept Architecture & Civil Engn, Kowloon, Hong Kong, Peoples R China.
关键词：
Bilayer nanosheets;graphenes and borophene;high-temperature deformation;molecular dynamics;structural stability
摘要：
Background: It has been found that the bilayer structure, especially the bilayer graphenes, can markedly weaken the anisotropy of elastic properties. For tri-layer systems, such as a monolayer grapheme sandwiched in bilayer graphenes and boron nitride nanosheets. The BN-G-BN achieves a more stable combined structure than G-G-G. The results further indicated that the high-temperature distortion resistance of interlayer graphene in the tri-layer complex is related to both material type and constrain conditions at the up-down layers. Methods: The structural stability and high temperature tolerance of bilayer complex nanoribbons are analyzed using the molecular dynamics method. By calculating a variety of potential functions between nanosheets and optimal interlayer distances, the differences in structural stability are examined. By simulating structural performance at high temperatures and analyzing the radial distribution function (RDF) and deformation electron density, the hightemperature distortion resistance is researched. Results: The optimal distances between layers are approximately 0.359 nm for bilayer borophene (B/B), 0.340 nm for bilayer graphene (G/G) and 0.348 nm for the hybrid bilayer (B/G). Analyzing of the results of the binding energy, interaction energy and van der Waals energies between nanosheets revealed that the structural stability of the bilayer complexes from high to low in turn are B/G, B/B and G/G. The dominant interaction sustaining complex stability is a typical van der Waals interaction. The structural analyses on the above complexes at high temperature (1500 K) indicated that the hybrid bilayer nanosheet B/G, in the three bilayer complexes, has the highest temperature tolerance, followed by G/G and then B/B. Conclusion: The results indicated that the bilayer borophene, especially for hybrid bilayer nanosheets, can help to improve the structural stability. The results revealed that the excitation of a greater number of local electrons in borophene results in the high temperature deformation resistance of B/B being inferior to that of G/G. The B/G, in three bilayer complexes composited with graphene and borophene, has the best structural stability and the highest temperature tolerance.
作者机构：
[Yuan, Jianhui] Changsha Univ Sci & Technol, Sch Phys & Elect Sci, Changsha 410114, Hunan, Peoples R China.;[Yuan, Jianhui; Liew, K. M.] City Univ Hong Kong, Shenzhen, Peoples R China.;[Zhang, L. W.] Shanghai Ocean Univ, Coll Informat Sci & Technol, Shanghai 201306, Peoples R China.;[Liew, K. M.] City Univ Hong Kong, Dept Architecture & Civil Engn, Kowloon, Hong Kong, Peoples R China.;[Liew, K. M.] City Univ Hong Kong, Shenzhen Res Inst Bldg,Shenzhen Hitech Ind Pk, Shenzhen, Peoples R China.
通讯机构：
[Liew, K. M.] C;City Univ Hong Kong, Shenzhen Res Inst Bldg,Shenzhen Hitech Ind Pk, Shenzhen, Peoples R China.
期刊：
Materials Chemistry and Physics,2014年145(3):313-319 ISSN：0254-0584
通讯作者：
Liew, K. M.
作者机构：
[Yuan, Jianhui] Changsha Univ Sci & Technol, Sch Phys & Elect Sci, Changsha 410114, Hunan, Peoples R China.;[Yuan, Jianhui; Liew, K. M.] City Univ Hong Kong, Dept Civil & Architectural Engn, Kowloon, Hong Kong, Peoples R China.;[Liew, K. M.] City Univ Hong Kong, Dept Civil & Architectural Engn, Tat Chee Ave, Kowloon, Hong Kong, Peoples R China.
通讯机构：
[Liew, K. M.] C;City Univ Hong Kong, Dept Civil & Architectural Engn, Tat Chee Ave, Kowloon, Hong Kong, Peoples R China.
关键词：
A. Nanostructures;B. Heat treatment;C. Computer modelling and simulation;C. Molecular dynamics;D. Elastic properties
作者机构：
[Yuan, Jianhui] Changsha Univ Sci & Technol, Sch Phys & Elect Sci, Changsha 410114, Hunan, Peoples R China.;[Yuan, Jianhui; Liew, K. M.] City Univ Hong Kong, Dept Architecture & Civil Engn, Kowloon, Hong Kong, Peoples R China.;[Liew, K. M.] City Univ Hong Kong, Shenzhen, Peoples R China.
通讯机构：
[Liew, K. M.] C;City Univ Hong Kong, Dept Architecture & Civil Engn, Kowloon, Hong Kong, Peoples R China.
期刊：
PHYSICAL CHEMISTRY CHEMICAL PHYSICS,2014年16(1):88-94 ISSN：1463-9076
通讯作者：
Liew, K. M.
作者机构：
[Yuan, Jianhui] Changsha Univ Sci & Technol, Sch Phys & Elect Sci, Changsha 410114, Hunan, Peoples R China.;[Yuan, Jianhui; Liew, K. M.] City Univ Hong Kong, Dept Civil & Architectural Engn, Kowloon, Hong Kong, Peoples R China.;[Liew, K. M.] City Univ Hong Kong, Dept Civil & Architectural Engn, Tat Chee Ave, Kowloon, Hong Kong, Peoples R China.
通讯机构：
[Liew, K. M.] C;City Univ Hong Kong, Dept Civil & Architectural Engn, Tat Chee Ave, Kowloon, Hong Kong, Peoples R China.
摘要：
Laser Raman spectrum method was used to study the hardness index of four water samples. The ratio of bending vibration peak intensity to stretching vibration peak intensity of these water samples was measured. The results showed that as the total hardness of water decreases, so does the ratio. This offers a possible new approach to water quality analysis that is both simple and effective.
期刊：
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY,2012年12(3):2617-2624 ISSN：1533-4880
通讯作者：
Liew, K. M.
作者机构：
[Yuan, Jianhui] Changsha Univ Sci & Technol, Sch Phys & Elect Sci, Changsha 410004, Hunan, Peoples R China.;[Yuan, Jianhui; Liew, K. M.] City Univ Hong Kong, Dept Civil & Architectural Engn, Kowloon, Hong Kong, Peoples R China.;[Liew, K. M.] City Univ Hong Kong, Dept Civil & Architectural Engn, Tat Chee Ave, Kowloon, Hong Kong, Peoples R China.
通讯机构：
[Liew, K. M.] C;City Univ Hong Kong, Dept Civil & Architectural Engn, Tat Chee Ave, Kowloon, Hong Kong, Peoples R China.
关键词：
Graphene and BNNS;Molecular Dynamics;Anisotropy;Thermo-Stability;Compressive Property
摘要：
The structural performance of graphene and boron-nitride nanosheet (BNNS) with zigzag and armchair types, when subjected to high temperatures, is investigated through molecular dynamics simulations. It is found that the degree of structure distortion is related to chirality; materials at high temperature of 3500 K, the zigzag nanosheet always exhibits less distortion than the armchair for the same material, and the BNNS exhibits less distortion than graphene for the same chirality. Graphene and BNNS with different in-plane compressive strains are optimized by using the Universal Force Field (UFF) method. It is found that there are two entirely different buckling modes, i.e., the lateral buckling of graphene begins to occur at the middle part, whereas buckling of BNNS begins to occur at near both ends and shows lateral deformation in two opposite directions. The coefficient of elasticity of graphene is slightly smaller than that of BNNS for the same chirality, the coefficient of elasticity of zigzag is slightly bigger than that of armchair for the same material, buckling strain of zigzag nanosheet is larger than that of armchair for the same material, and buckling strains of graphene are always larger than those of BNNS. These phenomena are also analyzed on the basis of radial distribution function (RDF) and system energy. The results indicate that there are thermal expansion anisotropy and planar stress anisotropy in a graphene and a BNNS. Among these materials, zigzag graphene has the highest resistance to compressive buckling but zigzag BNNS can have the highest resistance to distortion at high-temperature distortion and have high compression elasticity.
作者机构：
[Yuan, Jianhui; Liew, K. M.] City Univ Hong Kong, Dept Bldg & Construct, Kowloon, Hong Kong, Peoples R China.;[Yuan, Jianhui] Changsha Univ Sci & Technol, Sch Phys & Elect Sci, Changsha 410114, Hunan, Peoples R China.;[Liew, K. M.] City Univ Hong Kong, Dept Bldg & Construct, Tat Chee Ave, Kowloon, Hong Kong, Peoples R China.
通讯机构：
[Liew, K. M.] C;City Univ Hong Kong, Dept Bldg & Construct, Tat Chee Ave, Kowloon, Hong Kong, Peoples R China.
摘要：
The structural performance of double-walled C(5, 5)@BN(10, 10) and C(5, 5)@C(10, 10) nanotubes subject to high temperatures is investigated through molecular dynamics simulations. It is found that the inner tube C(5, 5) in the C(5, 5)@BN(10, 10) exhibits less distortion than that in the C(5, 5)@C(10, 10) at annealing temperatures of 3500 and 4000 K. The C(5, 5)@BN(10, 10) and C(5, 5)@C(10, 10) models with different axial compressive strains are optimized using the universal force field (UFF) method. It is found that the critical buckling strains of the inner tubes in the C(5, 5)@BN(10, 10) and C(5, 5)@C(10, 10) are 12.74% and 9.1%, respectively. The critical buckling strain of the former is larger than that of the latter; although the former exhibits greater deformation and energy loss after buckling than does the latter. These phenomena are also analyzed on the basis of the radial distribution function (RDF) and system energy. The results of this study indicate that the outer tube boron nitride nanotube (BNNT) has a better protective effect on the inner tube than does the outer tube carbon nanotube (CNT) under both high-temperature and lower compressive strain conditions. In these cases, the thermal stability and compressive resistance properties of the C(5, 5)@BN(10, 10) are superior to those of the C(5, 5)@C(10, 10).
作者机构：
[马忠权] Shu-Solare R and D Joint Laboratory, Department of Physics, Shanghai University, Shanghai 200444, China;[袁剑辉] School of Physics and Electronic Science, Changsha University of Science and Technology, Changsha, Hunan 410114, China;[杨昌虎] Shu-Solare R and D Joint Laboratory, Department of Physics, Shanghai University, Shanghai 200444, China<&wdkj&>School of Physics and Electronic Science, Changsha University of Science and Technology, Changsha, Hunan 410114, China
通讯机构：
[Yang, C.] S;Shu-Solare R and D Joint Laboratory, Department of Physics, Shanghai University, China
作者机构：
[Yuan, Jianhui] Changsha Univ Sci & Technol, Sch Phys & Elect Sci, Changsha 410114, Hunan, Peoples R China.;[Yuan, Jianhui; Liew, K. M.] City Univ Hong Kong, Dept Bldg & Construct, Kowloon, Hong Kong, Peoples R China.;[Liew, K. M.] City Univ Hong Kong, Dept Bldg & Construct, Tat Chee Ave, Kowloon, Hong Kong, Peoples R China.
通讯机构：
[Liew, K. M.] C;City Univ Hong Kong, Dept Bldg & Construct, Tat Chee Ave, Kowloon, Hong Kong, Peoples R China.
