Sow Thistle Chloroplast Genomes: Insights into the Plastome Evolution and Relationship of Two Weedy Species, Sonchus asper and Sonchus oleraceus (Asteraceae)

Prickly sow thistle, Sonchus asper (L.) Hill, and common sow thistle, Sonchus oleraceus L., are noxious weeds. Probably originating from the Mediterranean region, they have become widespread species. They share similar morphology and are closely related. However, they differ in their chromosome numbers and the precise relationship between them remains uncertain. Understanding their chloroplast genome structure and evolution is an important initial step toward determining their phylogenetic relationships and analyzing accelerating plant invasion processes on a global scale. We assembled four accessions of chloroplast genomes (two S. asper and two S. oleraceus) by the next generation sequencing approach and conducted comparative genomic analyses. All the chloroplast genomes were highly conserved. Their sizes ranged from 151,808 to 151,849 bp, containing 130 genes including 87 coding genes, 6 rRNA genes, and 37 tRNA genes. Phylogenetic analysis based on the whole chloroplast genome sequences showed that S. asper shares a recent common ancestor with S. oleraceus and suggested its likely involvement in a possible amphidiploid origin of S. oleraceus. In total, 79 simple sequence repeats and highly variable regions were identified as the potential chloroplast markers to determine genetic variation and colonization patterns of Sonchus specie

New discrete method for investigating the response properties in finite electric field

In this paper we develop a new discrete method for calculating the dielectric tensor and Born effective charge tensor in finite electric field by using Berry's phase and the gauge invariance. We present a new method to overcome non-periodicity of the potential in finite electric field due to the gauge invariance, and construct the dielectric tensor and Born effective charge tensor that satisfy translational symmetry in finite electric field. In order to demonstrate the correctness of this method, we also perform calculations for the semiconductors AlAs and GaAs under the finite electric field to compare with the preceding method and the experiment.Comment: arXiv admin note: text overlap with arXiv:cond-mat/0612442 by other author

Exciton-Plasmon Coupling Effects on the Nonlinear Optical Susceptibility of Hybrid Quantum Dot-Metallic Nanoparticle System

We have studied theoretically the exciton-plasmon coupling effects on the third-order optical nonlinearity of a coherently coupled hybrid system of a metal nanoparticle and a semiconductor quantum dot in the presence of a strong control field with a weak probe field

Study on acoustic radiation impedance at aperture of a waveguide with circular cross section taking account of interaction between different guided modes

In this paper we simulated self- and mutual- acoustic impedances of guided modes at the aperture and estimated accuracy of the piston radiation approximation. We used the Rayleigh integral to simulate the interactions between different guided modes at the aperture, with low time-consuming. This kind of guided-wave technique can be utilized to solve problems in diverse fields of wave science such as acoustics, electromagnetism and optics. For acoustic waves emitted through a horn or a waveguide with an aperture much smaller than the wavelength, there are only plane wave modes in the waveguide and the aperture of horn can therefore be considered as a piston radiator. However if an acoustic wave with high frequency such as ultrasonic wave is radiated, there can exist several guided modes in the duct. For arbitrary shape and size of waveguide, interactions between different modes must be taken into account to evaluate sound field in the duct and total acoustic power from its aperture. In this paper we simulated self- and mutual- acoustic impedances of guided modes at the aperture and estimated accuracy of the piston radiation approximation. We used the Rayleigh integral to simulate the interactions between different guided modes at the aperture, with low time-consuming. This kind of guided-wave technique can be utilized to solve problems in diverse fields of wave science such as acoustics, electromagnetism and optics

Influence of Pulse width and Rabi frequency on the Population dynamics of three-level system in two-photon absorption process

We investigate the population dynamics of the three-level system in the two-photon absorption (TPA) process, mainly focusing the influence of pulse width and Rabi frequency on the population dynamics of the system. We observe the dependency of the population with the Rabi frequency and the pulse width. We also show that the arbitrary superposition state consisted in two states, upper state and lower state, is possible by controlling the pulse width and Rabi frequency. The results obtained can be used to the case of more complex multilevel system and they can be valuable for coherent quantum control in quantum information processing.Comment: arXiv admin note: text overlap with arXiv:quant-ph/0402155 by other authors without attributio

Study on the Vibration Displacement Distribution of a Circular Ultrasonic Motor Stator

In this paper is presented a theoretical consideration on the stator's displacement distribution, which is one of the most important problems in defining the structure of the circular ultrasonic motor stator. The results are compared with results obtained utilizing holographic interferometer, laser vibrometer and a FEM (finite element method) simulation. They are in a good agreement with each other

Defect energetics and electronic structures of As-doped p-type ZnO crystals: A first-principles study

First-principles calculations based on density functional theory have been carried out to understand the mechanism of fabricating As-doped p-type ZnO semiconductors. It has been confirmed that AsZn-2VZn complex is the most plausible acceptor among several candidates for p-type doping by computing the formation and ionization energies. The electronic band structures and atomic-projected density of states of AsZn-2VZn defect complex-contained ZnO bulks have been computed. The acceptor level in AsZn-2VZn band structure has found to be 0.12 eV, which is in good agreement with the experimental ionization energy (0.12 ~ 0.18 eV). The hybridization among O 2p, Zn 3d and As 4s states has been observed around the valence band maximum

Control of the Optical Response of an Artificial Hybrid Nanosystem Due to the Plasmon-Exciton Plasmon Coupling Effect

The optical response of an artificial hybrid molecule system composed of two metallic nanoparticles (MNPs) and a semiconductor quantum dot (SQD) is investigated theoretically due to the plasmon-exciton-plasmon coupling effects on the absorption properties of the hybrid nanosystem, which depends on the interaction between the induced dipole moments in the SQD and the MNPs, respectively. We show that the strong coupling of exciton and localized surface plasmons in such a hybrid molecules leads to appealing, tunable optical properties by adjusting the symmetry of the hybrid molecule nanosystem with controllable interparticle distances. We also address here the influence of the size of the MNPs and dielectric constant of the background medium on the optical absorption of the MNPs and SQD, respectively, which results in the interparticle Foster resonance energy transfer (FRET). Our results will open an avenue to deal with the surface-enhanced spectroscopies and potential application of the quantum information

Plasmonic Effect on the Population Dynamics and the Optical Response in a Hybrid V-Type Three-Level Quantum Dot-Metallic Nanoparticle Nanosystem

We investigated theoretically the exciton-plasmon coupling effects on the population dynamics and the absorption properties of a hybrid nanosystem composed of a metal nanoparticle (MNP) and a V-type three level semiconductor quantum dot (SQD), which are created by the interaction with the induced dipole moments in the SQD and the MNP, respectively. Excitons of the SQD and the plasmons of the MNP in such a hybrid nanosystem could be coupled strongly or weakly to demonstrate novel properties of the hybrid system. Our results show that the nonlinear optical response of the hybrid nanosystem can be greatly enhanced or depressed due to the exciton-plasmon couplings.Comment: 12 pages, 6 figures. arXiv admin note: substantial text overlap with arXiv:1507.0445

Interparticle Coupling Effects of Two Quantum Dots System on the Transport Properties of a Single Plasmon

Transport properties of a single plasmon interacting with two quantum dots (QDs) system coupled to one-dimensional surface plasmonic waveguide are investigated theoretically via the real-space approach. We mainly focus on the coupling effects of the two QDs on the transmission properties of a single incident plasmon. We demonstrated that switching of a single plasmon can be achieved by controlling the interparticle distance, the interparticle coupling strength, and the QD-waveguide coupling strength, as well as spectral detuning. We also showed that the coupling between the continuum excitations and the discrete excitations results in the Fano-type transmission spectrum. The transport properties of a single plasmon interacting with such a two direct coupled QDs system could find the applications in the design of plasmonic nanodevices, such as single photon switching and nanomirrors, and in quantum information processing