Harvesting Plasmonic Excitations in Graphene for Tunable Terahertz/Infrared Metamaterials

In this chapter, we focus on the development on tunable terahertz/infrared metamaterials enabled with plasmonic excitations in graphene micro-/nanostructures. We aimed the issue that high loss in the plasmonic excitations of graphene limits the performance of graphene’s ability in manipulating light. We show the enhancement of light-graphene interactions by employing plasmonic metamaterial design for proper plasmonic excitations, and coherent modulation on optical fields to further increase the bonding of light field for boosted plasmonic excitations. The enhanced plasmonic excitations in graphene provide the possibility of practical applications for terahertz and infrared band graphene photonics and optoelectronics

Analysis of Vibration Attenuation and Energy Consumption of Blasting Demolition Chimney: A Case Study

Demolishing a tall chimney by directional blasting can save time and cost. However, the blasting vibration and the touchdown vibration of the parts of the chimney falling to the ground will cause noise disturbance to the local residents. To reduce the vibration effect of blasting demolition of the chimney, taking the 180 m high chimney in Jiaozuo, China, as the engineering background, the loose accumulation body with a right-angled trapezoid section 3-6 m thick was piled with three kinds of graded gravel particles as the buffer layer. According to the site restrictions, the chimney was demolished by directional blasting in two stages. The vibration propagation and attenuation rules of the blasting demolition of the chimney were analyzed and touchdown vibrations of two parts of the chimney were monitored also. Results show that the low frequency vibrations generated by the blasting and chimney touchdown have a greater impact on the surrounding environment. The vibration velocity and energy attenuation represent a form of power function. With the increase of the number of chimney touchdowns, the energy absorption rate of the loose accumulation body becomes lower. The obtained conclusions in this study can provide a reference for the similar blasting demolition practice

Mychonastes afer HSO-3-1 as a potential new source of biodiesel

<p>Abstract</p> <p>Background</p> <p>Biodiesel is considered to be a promising future substitute for fossil fuels, and microalgae are one source of biodiesel. The ratios of lipid, carbohydrates and proteins are different in different microalgal species, and finding a good strain for oil production remains a difficult prospect. Strains producing valuable co-products would improve the viability of biofuel production.</p> <p>Results</p> <p>In this study, we performed sequence analysis of the 18S rRNA gene and internal transcribed spacer (ITS) of an algal strain designated HSO-3-1, and found that it was closely related to the <it>Mychonastes afer </it>strain CCAP 260/6. Morphology and cellular structure observation also supported the identification of strain HSO-3-1 as <it>M. afer</it>. We also investigated the effects of nitrogen on the growth and lipid accumulation of the naturally occurring <it>M. afer </it>HSO-3-1, and its potential for biodiesel production. In total, 17 fatty acid methyl esters (FAMEs) were identified in <it>M. afer </it>HSO-3-1, using gas chromatography/mass spectrometry. The total lipid content of <it>M. afer </it>HSO-3-1 was 53.9% of the dry cell weight, and we also detected nervonic acid (C24:1), which has biomedical applications, making up 3.8% of total fatty acids. The highest biomass and lipid yields achieved were 3.29 g/l and 1.62 g/l, respectively, under optimized conditions.</p> <p>Conclusion</p> <p>The presence of octadecenoic and hexadecanoic acids as major components, with the presence of a high-value component, nervonic acid, renders <it>M. afer </it>HSO-3-1 biomass an economic feedstock for biodiesel production.</p

Achieving a high-Q response in metamaterials by manipulating the toroidal excitations

The excitation of toroidal multipoles in metamaterials is investigated for a high- Q response at a subwavelength scale. In this paper, we explore the optimization of toroidal excitations in a planar metamaterial comprised of asymmetric split ring resonators (ASRRs). It is found that the scattering power of a toroidal dipole can be remarkably strengthened by adjusting the characteristic parameter of ASRRs: an asymmetric factor. Interestingly, the improvement in toroidal excitation accompanies an increment of the Q factor of the toroidal metamaterial; it is shown that both the scattering power of the toroidal dipole and the Q factor increase more than one order by changing the asymmetric factor of ASRRs. The optimization in the excitation of a toroidal multipole provides an opportunity to further increase the Q factor of the metamaterial and boost light-matter interactions at the subwavelength scale for potential applications in low-power nonlinear processing and sensitive photonic applications

Graphene Plasmonics: A Platform for 2D Optics

2D optics is gradually emerging as a frontier in modern optics. Plasmons in graphene provide a prominent platform for 2D optics in which the light is squeezed into atomic scale. This report highlights some recent progresses in graphene plasmons toward the 2D optics. The launch, observation, and advanced manipulation of propagating graphene plasmons for 2D optical circuits are described. Representative achievements associated with graphene metasurfaces, challenges, recent progresses like photoexcited graphene metasurfaces, and the transformation optics linking 2D to bulk optics with singularity are investigated

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead