Maxwell-Hydrodynamic Model for Simulating Nonlinear Terahertz Generation from Plasmonic Metasurfaces

The interaction between the electromagnetic field and plasmonic nanostructures leads to both the strong linear response and inherent nonlinear behavior. In this paper, a time-domain hydrodynamic model for describing the motion of electrons in plasmonic nanostructures is presented, in which both surface and bulk contributions of nonlinearity are considered. A coupled Maxwell-hydrodynamic system capturing full-wave physics and free electron dynamics is numerically solved with the parallel finite-difference time-domain (FDTD) method. The validation of the proposed method is presented to simulate linear and nonlinear responses from a plasmonic metasurface. The linear response is compared with the Drude dispersion model and the nonlinear terahertz emission from a difference-frequency generation process is validated with theoretical analyses. The proposed scheme is fundamentally important to design nonlinear plasmonic nanodevices, especially for efficient and broadband THz emitters.Comment: 8 pages, 7 figures, IEEE Journal on Multiscale and Multiphysics Computational Techniques, 201

Full Hydrodynamic Model of Nonlinear Electromagnetic Response in Metallic Metamaterials

Applications of metallic metamaterials have generated significant interest in recent years. Electromagnetic behavior of metamaterials in the optical range is usually characterized by a local-linear response. In this article, we develop a finite-difference time-domain (FDTD) solution of the hydrodynamic model that describes a free electron gas in metals. Extending beyond the local-linear response, the hydrodynamic model enables numerical investigation of nonlocal and nonlinear interactions between electromagnetic waves and metallic metamaterials. By explicitly imposing the current continuity constraint, the proposed model is solved in a self-consistent manner. Charge, energy and angular momentum conservation laws of high-order harmonic generation have been demonstrated for the first time by the Maxwell-hydrodynamic FDTD model. The model yields nonlinear optical responses for complex metallic metamaterials irradiated by a variety of waveforms. Consequently, the multiphysics model opens up unique opportunities for characterizing and designing nonlinear nanodevices.Comment: 11 pages, 14 figure

Application of nursing core competency standard education in the training of nursing undergraduates

AbstractPurposeTo evaluate the effectiveness of nursing core competency standard education in undergraduate nursing training.MethodsForty-two nursing undergraduates from the class of 2007 were recruited as the control group receiving conventional teaching methods, while 31 students from the class of 2008 were recruited as the experimental group receiving nursing core competency standard education. Teaching outcomes were evaluated using comprehensive theoretical knowledge examination and objective structured clinical examination.ResultsThe performance in the health information collection, physical assessment, scenario simulation and communication in the experimental group were significantly higher than those of the control group (p < 0.05).ConclusionsNursing core competency standard education is helpful for the training of nursing students' core competencies

(4-Carb­oxy-2-sulfonato­benzoato-κ2 O 1,O 2)bis­(1,10-phenanthroline-κ2 N,N′)manganese(II)

In the title complex, [Mn(C8H4O7S)(C12H8N2)2], the MnII atom is chelated by one 4-carb­oxy-2-sulfonato­benzoate anion and two phenathroline (phen) ligands in a distorted octa­hedral MnN4O2 geometry. The benzene ring of the 4-carb­oxy-2-sulfonato­benzoate anion is twisted with respect to the two phen ring systems at dihedral angles of 66.38 (9) and 53.56 (9)°. In the crystal, inter­molecular O—H⋯O and C—H⋯O hydrogen bonding links the mol­ecules into chains running parallel to [100]. Inter­molecular π–π stacking is also observed between parallel phen ring systems, the face-to-face distance being 3.432 (6) Å