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Journal ArticleDOI

Raman spectrum of graphene and graphene layers.

TL;DR: This work shows that graphene's electronic structure is captured in its Raman spectrum that clearly evolves with the number of layers, and allows unambiguous, high-throughput, nondestructive identification of graphene layers, which is critically lacking in this emerging research area.
Abstract: Graphene is the two-dimensional building block for carbon allotropes of every other dimensionality We show that its electronic structure is captured in its Raman spectrum that clearly evolves with the number of layers The D peak second order changes in shape, width, and position for an increasing number of layers, reflecting the change in the electron bands via a double resonant Raman process The G peak slightly down-shifts This allows unambiguous, high-throughput, nondestructive identification of graphene layers, which is critically lacking in this emerging research area

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Journal ArticleDOI
TL;DR: A comprehensive review of the properties, synthesis, characterisation, and application of 2D materials in the context of electrochemistry and related scientific fields is presented in this article, with a focus on group 6 transition metal dichalcogenides (TMDCs).

200 citations

Journal ArticleDOI
01 Aug 2015-Carbon
TL;DR: In this paper, Bilayer-free monolayer graphene was obtained by a careful pre-annealing step and by optimizing the H2 flow during growth, and as-grown graphene was transferred using an improved wet chemical graphene transfer process.

199 citations

Journal ArticleDOI
TL;DR: In this article, the authors reviewed how optical properties of typical 2D materials (e.g., monolayer and multilayer graphenes, transition metal dichalcogenides) probed by these optical techniques significantly depend on the layer number (N).
Abstract: The quantum confinement in atomic scale and the presence of interlayer coupling in multilayer make the electronic and optical properties of 2D materials (2DMs) be dependent on the layer number (N) from monolayer to multilayer. Optical properties of 2DMs have been widely probed by several optical techniques, such as optical contrast, Rayleigh scattering, Raman spectroscopy, optical absorption, photoluminescence, and second harmonic generation. Here, it is reviewed how optical properties of several typical 2DMs (e.g., monolayer and multilayer graphenes, transition metal dichalcogenides) probed by these optical techniques significantly depend on N. Further, it has been demonstrated how these optical techniques service as fast and nondestructive approaches for N counting or thickness determination of these typical 2DM flakes. The corresponding approaches can be extended to the whole 2DM family produced by micromechanical exfoliations, chemical-vapor-deposition growth, or transfer processes on various substrates, which bridges the gap between the characterization and international standardization for thickness determination of 2DM flakes.

199 citations

Journal ArticleDOI
01 Feb 2014-Carbon
TL;DR: In this paper, the authors report on preparation technique and tribological properties of multilayer graphene reinforced TiAl matrix composites (GTMC). GTMC are successfully prepared by spark plasma sintering (SPS) using Raman spectroscopy and field emission scanning electron microscopy, which indicates that MLG homogeneously distributes in GTMC.

199 citations


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PatentDOI
TL;DR: A new, environmentally stable hydrogen storage material constructed of Mg nanocrystals encapsulated by atomically thin and gas-selective reduced graphene oxide (rGO) sheets that exhibits exceptionally dense hydrogen storage and provides a material platform for harnessing the attributes of sensitive nanomaterials in demanding environments.
Abstract: Various embodiments of the invention describe an environmentally stable, and exceptionally dense hydrogen storage (6.5 wt% and 0.105 kg H2/L in the total composite, 7.56 wt% in Mg) using atomically thin and gas-selective reduced graphene oxide sheets as encapsulants. Other approaches to protecting reactive materials involve energy intensive introduction of considerable amounts of inactive, protective matrix which compromises energy density. However, these multilaminates are able to deliver exceptionally dense hydrogen storage far-exceeding 2020 DOE target metrics for gravimetric capacity (5.5 wt%), and ultimate full- fleet volumetric targets (0.070 kg H 2 /L) for fuel cell electric vehicles. Methods of stabilizing reactive nanocrystalline metals in zero-valency also has wide-ranging applications for batteries, catalysis, encapsulants, and energetic materials.

198 citations

References
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28 Jul 2005
TL;DR: PfPMP1)与感染红细胞、树突状组胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作�ly.
Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1(PfPMP1)与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员,通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

18,940 citations