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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TL;DR: In this article, the use of GNPs to strengthen the bulk Cu-matrix composites was reported, and the GNP reinforced composites were prepared by a combination of the ball milling and hot-pressing processing, and their mechanical properties were investigated.
Abstract: Graphene nanoplatelets (GNPs) exhibit ultra-high strength and elastic modulus. Therefore, they are potential ideal reinforcements in metal–matrix composites (MMCs). In this work, we report the use of GNPs to strengthen the bulk Cu-matrix composites. GNP reinforced Cu-matrix (GNP/Cu) composites were prepared by a combination of the ball milling and hot-pressing processing, and their mechanical properties were investigated. Microstructure studies indicated that the GNPs with 0–8 vol.% contents were well dispersed in the Cu matrix by ball milling. Compared to unreinforced Cu, the GNP/Cu composites showed a remarkable increase in yield strength and Young's modulus up to 114 and 37% at 8 vol.% GNP content, respectively. The extraordinary reinforcement is attributed to the homogeneous dispersion of GNPs and grain refinement. However, the mechanical improvement of GNP/Cu composites was still below the theoretical value. The possible reasons for this deviation were discussed and the methods for further mechanical improvement of GNP/Cu composites were proposed.
248 citations
TL;DR: In this paper, thermal effects on the Raman spectra of molybdenum disulfide with thicknesses ranging from bulk to monolayer were evaluated and quantitatively determined the laser-induced heating effects on peak position and the line width of the spectrum.
Abstract: In this letter, thermal effects on the Raman spectra of molybdenum disulfide with thicknesses ranging from bulk to monolayer were evaluated. We quantitatively determined the laser-induced heating effects on the peak position and the line-width of the Raman spectrum. We found considerable thickness-dependent red-shifts as well as line-width changes for both E2g1 and A1g vibrating modes as laser power was increased. Our results enrich the knowledge of phononic behaviors of this material and demonstrate the important effects of the anharmonic terms in the lattice potential energy.
247 citations
TL;DR: In this article, the sulfonated graphene acid catalyst was characterized by electron microscopy, Raman spectroscopy, solid state 13C MAS NMR, energy dispersive spectrograms (EDS), and X-ray photoelectron spectrography (XPS).
Abstract: Acid catalysts are essential for various chemical reactions in the industrial hydrocarbon chemistry. Sulfonated carbon has shown promising application as a new, cheap and environmentally friendly solid acid catalyst. In this study, we prepared the sulfonated graphene acid catalyst, and it was characterized by electron microscopy, Raman spectroscopy, solid state 13C MAS NMR, energy dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). Catalytic hydrolysis of ethyl acetate shows that the sulfonated graphene has highly catalytic activity and can be repetitively used as a water-tolerant solid acid catalyst.
247 citations
TL;DR: In this paper, a stringed tube on cube nanohybrid (CPZC) with a ternary hierarchical architecture is proposed to accelerate the sulfur redox kinetics and promote battery durability.
Abstract: The rational design of cathode host materials is significant in fulfilling high-efficiency sulfur electrochemistry as well as boosting the energy density of lithium–sulfur (Li–S) batteries. Herein, we develop a stringed “tube on cube” nanohybrid (CPZC) with a ternary hierarchical architecture, which contains a fibrous carbon skeleton, highly porous carbon cube filler, and abundant CNT tentacles as an advanced matrix for sulfur electrodes. The as-developed CPZC delivers excellent conductivity, abundant active interfaces, and strong confinement to polysulfide, and thus is capable of significantly expediting the sulfur redox kinetics and promoting battery durability. The fabricated sulfur electrode achieves a superb rate capability up to 10C, outstanding cyclability over 2000 cycles, and more importantly, excellent performance under high a sulfur loading and sparing electrolyte with a high energy density of 348.8 W h kg−1 and 327.6 W h L−1 at the system level, which reveals its potential in promoting the practical application of Li–S batteries.
246 citations
TL;DR: In this paper, the authors studied the parameters required for the formation of varied laser-induced graphene (LIG) morphologies by tuning the laser radiation energy and showed that a morphology of LIG nanomaterial, LIG fibers, can be generated by this one-step laser photothermolysis process at a radiation energy >40 J/cm2.
246 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