Excitation of Zonal Flows by ion-temperature-gradient Modes Excited by the Fluid Resonance

We apply the reductive perturbation method to the simple electrostatic ion-temperature-gradient mode in an advanced fluid description. The fluid resonance turns out to play a major role for the excitation of zonal flows. This is the mechanism recently found to lead to the low-to-high （L-H） mode transition and to the nonlinear Dimits upshift in transport code simulations. It is important that we have taken the nonlinear temperature dynamics from the Reynolds stress as the convected diamagnetic flow. This has turned out to be the most relevant effect as found in transport simulations of the L-H transition, internal transport barriers and Dimits shift. This is the first time that an analytical method is applied to a system which numerically has been found to give the right experimental dynamics.

On rotational normal modes of the Earth：Resonance,excitation,convolution, deconvolution and all that

Earth＇s Coriolis force profoundly alters the eigen frequencies, eigen functions, and excitation of rotational normal modes. Some rotational modes of the solid mantle-fluid outer core-solid inner core Earth system are confirmed observationally and some remain elusive. Here we bring together from literature assertions about an excited resonance system in terms of the Green＇s function and temporal convolution. We raise caveats against taking the face values of the oscillational motion which have been ＂masqueraded＂ by the convolution, necessitating deconvolution for retrieving the excitation function which reflects the true variability. Lastly we exemplify successful applications of the deconvolution in estimating resonance complex frequencies.

Electrochemical Study of Cadmium (Ⅱ) Complexation with Cysteine

The complexation of Cd with cysteine has been investigated at pH ~9, and in constant ionic medium 0.59 M NaNO3 and borate buffer. Reduction signals of the hydrated Cd2+ and Cd-cysteinate complex were resolved on the potential scale during amperometric titration of 2 × 10-6 M Cd2+ with cysteine and cysteine with Cd2+, in a differential pulse (DP) mode on HMDE. The 1:1 molar ratio of Cd2+ to cysteine, and cysteine to Cd2+, was defined for Cd-cysteinate complex formed under the defined conditions. The appearance of the prepeak on the Cd-cysteinate reduction signal is showed, as the result of cysteine adsorption in reduced form. From the mass balance equations, the stoichiometric stability constants of Cd-cysteinate complex were calculated. Under various experimental conditions, comparable log K values were obtained. The grand average log K = 7.83 M-1 refers to 0.59 M ionic strength and 23℃.

Study on switched reluctance generator

The linear and non-linear math models of the switched reluctance generator (SRG) in generator mode were established in this work. The phase current and energy conversion process during generator operation were simulated by the linear math model. The non-linear math model was used to analyze the characteristics of the SRG operation in self-excitation mode and in separately-excitation mode. Some important findings on how the SRG is operated and controlled were obtained in this study, which provides theoretical basis for further design and experimental study.

GUIDED CIRCUMFERENTIAL WAVES IN DOUBLE-WALLED CARBON NANOTUBES

A model of guided circumferential waves propagating in double-walled carbon nanotubes is built by the theory of wave propagation in continuum mechanics, while the van der Waals force between the inner and outer nanotube has been taken into account in the model. The dispersion curves of the guided circumferential wave propagation are studied, and some dispersion characteristics are illustrated by comparing with those of single-walled carbon nanotubes. It is found that in double-walled carbon nanotubes, the guided circumferential waves will propagate in more dispersive ways. More interactions between neighboring wave modes may take place. In particular, it has been found that a couple of wave modes may disappear at a certain frequency and that, while a couple of wave modes disappear, another new couple of wave modes are excited at the same wave number.

Spatial evolution of the near-field distribution on planar gold nanoparticles with the excitation wavelength across dipole and quadrupole modes

We investigate the superposition properties of the dipole and quadrupole plasmon modes in the near field both experimentally, by using photoemission electron microscopy(PEEM), and theoretically. In particular, the asymmetric near-field distributions on gold(Au) nanodisks and nanoblocks under oblique incidence with different polarizations are investigated in detail. The results of PEEM measurements show that the evolutions of the asymmetric near-field distributions are different between the excitation with s-polarized and p-polarized light.The experimental results can be reproduced very well by numerical simulations and interpreted as the superposition of the dipole and quadrupole modes with the help of analytic calculations. Moreover, we hypothesize that the electrons collected by PEEM are mainly from the plasmonic hot spots located at the plane in the interface between the Au particles and the substrate in the PEEM experiments.

Loss characteristics of helical-core fiber

A special optical fiber is investigated, which has a helical core in the cylindrical cladding. The beam propagation method （BPM） is used for analyzing the impacts of the geometric and physical parameters on the properties of mode losses of the helical-core fiber. The propagation loss is 0.32 dB/m for the fundamental mode and the propagation loss is 20.95 dB/m for the LPu mode in the wavelength range of 1050-1065 nm when the core diameter is 19 μm, the pitch of the core＇s helix is 2.66 mm, and the offset of the helix core from the center of the fiber axis is 31 μm. The core diameter of the single-mode helical-core fiber well exceeds that of the conventional large-mode-area fiber. The helical-core fiber can provide the effec- tive large-mode-area single-mode operation without coiling fiber or selecting excitation mode.

Interface-facilitated energy transport in coupled Frenkel-Kontorova chains

The role of interface couplings on the energy transport of two coupled Frenkel-Kontorova （FK） chains is explored through numerical simulations. In general, it is expected that the interface cou- plings result in the suppression of heat conduction through the coupled system due to the additional interface phonon-phonon scattering. In the present paper, it is found that the thermal conductivity increases with increasing intensity of interface interactions for weak inter-chain couplings, whereas the heat conduction is suppressed by the interface interaction in the case of strong inter-chain couplings. Based on the phonon spectral energy density method, we demonstrate that the enhance- ment of energy transport results from the excited phonon modes （in addition to the intrinsic phonon modes）, while the strong interface phonon-phonon scattering results in the suppressed energy transport.

Absorption density control in waveguide photodiode- analysis, design, and demonstration

A modal analysis is conducted for analyzing the absorption profile of high power waveguide photodiodes designed for analog optical link. The excitation of guided modes with large filling factor in the absorber is identified as a limiting factor for the performance of waveguide photodiodes at high optical power, including power handling capability, and bandwidth-efficiency product. A waveguide photodiode design, which spatially separates the input waveguide from the absorber in the lateral direction, is analyzed and experimentally demon- strated to suppress the excitation of mode with large filling factor. Photocurrent 〉 60 mA under - 4 V bias is measured, with 0.80 A/W responsivity. This design illustrates that high power handling capability can be achieved without compromising the bandwidth-efficiency product.

Incident Light Influence on the Transmission of Coupled Ring Resonators

The transmission matrix method is used to analyze the influence of incident light on coupled resonators. Two different types of incident light on the same coupled resonator geometry are shown to lead to different system transmission features. The EIT-like phenomenon occurs in the type I case with the transmission being symmetric around the zero-single-pass-phase-shift frequency. In the type Ⅱcase the resonant frequency has a blue shift corresponding to the increasing coupling strength between the two ring resonators. Also, the critical-coupling-like condition exists in the type Ⅱconfiguration to maintain the zero-single pass-phase-shift frequency. The incident light, as well as the geometry, partially determine the mode interference in the coupled ring resonator system.