磷烯的研究进展与展望

黑磷晶体的单原子层结构被定义为磷烯，它具有独特的褶皱形态和一些区别于其它二维晶体材料的特性，如可调控的直接带隙，高开关比，高载流子迁移率以及优异的光学饱和吸收特性等，使其在纳米电子和纳米光学领域具有潜在应用价值.此外，蓝磷烯被理论计算所预测，它是黑磷烯的一种同素异形体，具有许多类似黑磷烯的优异特性.本文主要介绍了当前两种构型磷烯的研究进展，包括黑/蓝磷烯各自的晶体结构、制备方法、物理特性和稳定性；最后对目前磷烯研究中存在的问题与挑战提出了一些见解和展望.     

Recent advances in the research of inorganic nanotubes and fullerene-like nanoparticles

This minireview outlines the main scientific directions in tile research of inorganic nanotubes （1NT） and fullerene-like （IF） nanoparticles from layered compounds, in recent years. In particular, this review describes to some detail the progress in the synthesis of new nanotubes, including those from misfit compounds; core-shell and the successful efforts to scale-up the synthesis of WS2 multiwalt nanotubes. The high-temperature catalytic growth of nanotubes, via solar ablation is discussed as well. Furthermore, the doping of the 1F-MoS2 nanoparticles and its influence on the physiochemical properties of the nanoparticles, including their interesting tribological properties are briefly discussed. Finally, the numerous applications of these nanoparticles as superior solid lubricants and for reinforcing variety of polymers are discussed in brief.     

稀土Gd掺杂新型二维材料磷烯改性研究

本文采用第一性原理赝势平面波法, 计算并分析了稀土Gd掺杂磷烯的物理结构、电子结构、磁性以及光学性质. 计算表明: 在掺杂原子Gd附近引起了磷烯物理结构上的变化. 能带数量明显增多变密, 带隙变窄由0.921eV变为0.578eV. 同时, 由于Gd原子的4f和5d轨道电子两种自旋取向分布具有不对称性, 给体系引入了强磁性, 计算得到的自旋磁矩为7.470B. 磷烯材料的复介电函数是各向异性的, 同时可以得出磷烯材料在其它光学性质方面也是各向异性的. Gd掺杂后使材料的介电性能增强. 在紫外光的能量范围内, 不同极化方向上的反射率和损失函数的峰值降低, 说明Gd的掺入使材料对紫外光的敏感度有所减弱. 希望以上研究结果能为新型二维材料磷烯在光电和稀磁半导体材料的设计与开发方面提供理论依据.     

Electronic properties of phosphorene and graphene nanoribbons with edge vacancies in magnetic field

The graphene and phosphorene nanostructures have a big potential application in a large area of today's research in physics. However, their methods of synthesis still don't allow the production of perfect materials with an intact molecular structure. In this paper, the occurrence of atomic vacancies was considered in the edge structure of the zigzag phosphorene and graphene nanoribbons. For different concentrations of these edge vacancies, their influence on the metallic properties was investigated. The calculations were performed for different sizes of the unit cell. Furthermore, for a smaller size, the influence of a uniform magnetic field was added.     

Recent Advances in Analytical Applications of Nanomaterials in Liquid-Phase Chemiluminescence

Abstract

In recent years, many nanomaterials-assisted chemiluminescence (CL) systems have been developed to improve the sensitivity and to expand the scope of their analytical applications. In these new systems, nanomaterials participate in CL reactions as catalysts, labels, reductants, luminophors, or energy acceptors. This review mainly focuses on the recent analytical applications of metal nanoparticles, magnetic nanoparticles, quantum dots (QDs), and carbon-based nanomaterials (carbon nanotubes and graphene) in liquid-phase CL systems. Recent advances in electrochemiluminescence based on nanotechnology and its analytical applications, especially in immunoassay, DNA analysis, and other biological analyses, are also summarized. Finally, we discuss some critical challenges in this field and speculate about their solutions. A total of 177 references mainly in the last 5 years are included in this review.     

First-principles study of the electronic structure and transport properties of armchair graphene nanoribbons with adsorbed super-halogen LiF2 and super-alkali Li3 clusters

The electronic structure and quantum transport properties of pristine armchair graphene nanoribbons (AGNRs) and AGNRs adsorbing super-halogen LiF₂ and super-alkaline Li₃ clusters (Li₃/AGNRs/LiF₂) were investigated using density functional theory and non-equilibrium Green's function calculations. It was found that LiF₂ and Li₃ clusters are stably adsorbed on the AGNRs, and the adsorption of Li₃ and LiF₂ endows AGNRs with the characteristics of n-type and p-type semiconductors, respectively. The Li₃/AGNRs/LiF₂ structure reduces the band gap and the turn-on voltage, and improves the transmission coefficient of the ANGRs device. This structure also exhibit the rectification characteristics of a pn junction with the forward bias current greater than the reverse bias current. This shows that adsorption of super-alkali and super-halogen clusters in different regions of AGNRs is a feasible approach for obtaining AGNRs with pn junction characteristics.     

A Review of the Recent Advances in Cyclic Butylene Terephthalate Technology and its Composites

Cyclic butylene terephthalate (CBT®) oligomers are a relatively new class of material and are capable of polymerizing in an entropically driven ring-opening polymerization into high-molecular-weight polymerized CBT (pCBT) in very short times, i.e., within minutes. The most important feature of CBT is its very low, water-like melt viscosity prior to polymerization which gives rise to an excellent impregnation of fibrous reinforcements in contrast to conventional, high viscous thermoplastic resins. This opens up new possibilities in the thermoplastic composite production since thermoplastic-based composites show some advantages over thermoset-based ones. Specifically, they have a higher toughness and impact strength and they can be welded, postformed, and recycled due to their thermoplastic nature. CBT has the potential to substitute thermoset matrices in fiber-reinforced composites and may solve some of the today´s recycling issues associated with thermoset-based composites. Moreover, the low melt viscosity of CBT enhances the dispersion of nano- or conductive particles and can yield superior nano- and conductive composites. This article reviews the recent advances in processing–structure–property relationship, physical and chemical modification of pCBT, as well as the preparation of fiber-reinforced pCBT composites, pCBT nanocomposites, and conductive pCBT composites.     

碳纳米管拉曼光谱研究新进展

本文介绍碳纳米管拉曼光谱研究的最新进展。重点介绍金属性和半导体性碳纳米管的共振拉曼效应、表面增强拉曼效应和偏振拉曼效应。同时也介绍了碳纳米管的温度效应、压力效应和杨氏模量的拉曼光谱研究     

Recent Advances in Spatial Self-Phase Modulation with 2D Materials and its Applications

In recent years, spatial self-phase modulation (SSPM) with two-dimensional (2D) materials has attracted the attention of many researchers as an emerging and ubiquitous nonlinear optical effect. In this review, the state of the art of 2D material-based SSPM is summarized. SSPM measures or tunes the nonlinearity of 2D materials, and it is also an effective approach to study the band structure of 2D materials. Several modified forms of SSPM, such as high-order, white-light-excited, vector field excited, and optically nonlinearly enhanced SSPM are also presented. Subsequently, the physical origin of the SSPM formation mechanism is compared and analyzed. Furthermore, the applications of SSPM with 2D materials, including passive photonic devices, generation of Bessel beams, and identifying the mode of the orbital angular momentum, are listed. Finally, several urgent problems of the SSPM with 2D materials, potential applications, and prospects for future development are presented.     

表面氧钝化碳化硅纳米团簇电子结构和光学性质的第一性原理研究

基于密度泛函理论(DFT)和广义梯度近似(GGA),对氧钝化条件下4H-SiC纳米团簇的电子结构和光学性质进行了研究。计算了不同直径的4H-SiC纳米球氧钝化后的能带结构、电子态密度和光学性质。团簇的尺度在0.4~0.9 nm之间,构建表面仅存在硅氧双键和表面仅存在碳氧双键的两种模型。研究表明硅氧双键和碳氧双键所引起的缺陷态位于原4H-SiC的价带和导带之间,并且缺陷态与价带顶的能量差随纳米团簇颗粒直径的增大而减小;缺陷态主要是由Si原子外层电子和氧原子外层电子轨道杂化引起的。同时,由于氧的存在,对碳化硅的结构产生一定的影响,这也是缺陷态形成的一个原因。另外,碳氧双键和硅氧双键钝化对4H-SiC纳米团簇的光学性质有着不同的影响。在表面仅存在C=O的情况下,4H-SiC纳米团簇表现出各向同性的性质。在表面仅存在Si=O的情况下,4H-SiC纳米团簇表现出各向异性的性质。     

Recent Advances in the Synthesis and Applications of Ultrasmall Bimetallic Nanoclusters

Ultrasmall bimetallic nanoclusters (or bi‐MNCs for short) have recently emerged as a new class of multi‐functional nanoparticles due to their ultrasmall size (typically below 2 nm), unique molecular‐like properties (e.g., quantized charging and strong luminescence), controlled cluster compositions (at the atomic level), synergistic physicochemical properties, and rich surface chemistry. Such intriguing properties have motivated the cluster community to develop efficient methods for the synthesis of high‐quality bi‐MNCs, which can also be seen from the quantum increase of reported synthetic protocols for bi‐MNCs. Recent advances in the development of efficient synthesis methods for high‐quality bi‐MNCs also facilitate the application explorations of bi‐MNCs in diverse fields like catalysis, sensors, and biomedicine. This Review article first surveys current progress in the synthesis of bi‐MNCs, especially for those NCs with good control of cluster size and composition, followed by a detailed discussion on some unique physicochemical properties of bi‐MNCs. The intriguing properties of bi‐MNCs have made them ideal platforms for application explorations in catalysis, sensors, and biomedicine, which are discussed in the second section. In the last section, a brief outlook on future developments of functional bi‐MNCs is presented, with a particular focus on the controlled synthesis and practical applications of bi‐MNCs.     

TCNQ和TMB电荷转移配合物自组装膜的制备及光谱研究

本文利用layer-by-layer技术制备了以TMB为电子给体以TCNQ为电子受体的电荷转移配合物自组装膜。在自组装膜的付立叶-红外透射光谱中TCNQ组分的C≡N的伸缩振动峰出现在2205cm-1,与游离的中性TCNQ中的C≡N峰位置明显不同。这不仅证明TCNQ和TMB确实形成了电荷转移配合物,而且可以据此计算出电荷转移配合物的电荷转移度为0.42。自组装膜的紫外-可见-近红外光谱中,出现一个非常宽的吸收带,中心位置在2030nm处,说明形成的电荷转移配合物是混合堆积排列。从原子力显微镜照片可以看出,电荷转移配合物自组装膜的表面形貌是由颗粒组成的,这些颗粒的尺寸约为80nm。     

Bi2S3纳米带的制备及其谱学性能研究

以硝酸铋、硫代乙酰胺和氨三乙酸等为原料,利用水热法在180℃下反应12h得到Bi2S3纳米带.X射线粉末衍射结果表明产物对应于正交晶相的Bi2 S3(JCPDS:17-320),晶胞参数为a=1.110 6 nm,1,b=1.099 3 nm,c=O.389 2 nm,与文献报道值(a=1.114 9nm ,b=1.1304 nm,c=O.3981 nm)基本一致;通过透射电镜观察其形貌为均匀的带状,宽约100 nm;高分辨透射电镜照片显示晶体沿y轴优先生长;通过对x射线光电子能谱分析得到Bi和S的原子个数比例约为2:3,与目标产物Bi2 S3的计量比一致;测试显示Bi2S3纳米带的拉曼吸收峰出现在195 cm-1处,与块体Bi2s3(236 cm-1)相比,其吸收峰红移了41 cm-1,体现了纳米材料的表面效应.紫外-可见吸收光谱研究发现Bi2S3纳米带在450nm左右有吸收,计算得到Eg约为1.58 eV(块体Bi2S3的巨为1.3 eV),在光电领域有潜在的应用价值.     

Simulation Study of the Electron and Hole Transport in a CNTFET

In this work we have investigated electron and hole transport through zig zag carbon nanotubes by solving Boltzmann Transport Equation(BTE).We find that the mobility of electrons is rather greater than holes.Carbo nanotubes with longer diameter can carry higher current.Normally,transport of electrons(or holes) is dominated by scattering events,which relax the carrier momentum in an effort to bring the conducting material to equilibrium.     

Scattering and Transmission by a Monolayer of Spheres: A Study on the Monolayer Structure

The angular distribution of scattered light and the transmission of radiation through a monolayer of monodisperse spherical particles at variable particle concentration are studied. The scattering of light by a single particle is calculated with the classical Lorentz‐Mie theory. For a monolayer of mono‐dispersed spherical particles, if the monolayer density is less than 0.5 and the particle size parameter is larger than 5, effects from multiple scattering and dependent scattering can be excluded so that only steric interactions are considered. It is found that the scattering pattern, especially in the forward and backward directions, and the transmission are strongly dependent on the monolayer density.     

拉曼光谱研究掺杂与非掺杂碳纳米管电子性质的新进展(英文)

本文综述了非掺杂和掺杂碳纳米管拉曼光谱研究的新进展,特别注意到了悬浮液中单个分散的单壁纳米管、硼和氮掺杂的纳米管、碱金属插入的纳米管以及用化学方法功能化的单壁纳米管的拉曼光谱与其电子性质的相关性。讨论了所存在的问题,展望了可能的发展方向。     

异质结构的应变和应力分布模型研究

基于组合杆的平衡条件，分别建立了晶格失配、热失配以及由两者共同导致的异质结构应变 和应力分布模型，并获得了异质结构的晶格失配应变、热失配应变、弯曲应变以及曲率半径 的分析解. 同时，运用所建的模型，计算了HgCdTe/CdZnTe异质结构的应变和应力分布.结果 表明：应力最大值均在界面处，而中性面仅是材料厚度和弹性参数的函数，与晶格失配、晶 格弛豫、热失配等参数无关，且该异质结构的曲率半径是衬底厚度的函数，随衬底厚度的减 小而减小，而要保证HgCdTe/CdZnTe器件在液氮温度下不发生断裂，衬底的厚度必须大于临界值. 关键词： 异质结构 应变分布模型 应力分布模型 晶格失配     

Recent Advances in the Use of Intrinsic Fluorescence for Bacterial Identification and Characterization

Live bacteria contain a variety of intracellular biomolecules that have specific excitation and emission wavelength spectra characterizing their intrinsic fluorescence. This paper reviews recent developed methods using bacterial intrinsic fluorescence for identification and characterization purposes. Potential applications of such methods at the industrial level are also addressed.     

平面超透镜的远场超衍射极限聚焦和成像研究进展

突破瑞利衍射极限,实现纯光学的远场超衍射极限聚焦和成像在科学和工程的各个领域都有重要意义.现有光学超分辨技术都存在一些固有的限制因素,如工作距离短、适用领域窄、不利于集成等问题.平面超透镜由于理论上的创新、设计灵活、效率高、方便集成等优势,成为实现超衍射极限的有效途径.本文综述了平面超透镜的物理原理及其在超衍射极限聚焦和成像方面近年来的研究进展,并讨论了该领域面临的问题和未来的研究重点和方向.