A subway train-steel spring floating slab track-tunnel coupling dynamic model, considering short and middle-long wavelength random track irregularities, and longitudinal connection between adjacent slabs of steel spring floating slab track, was developed. And the influence of slab length on dynamic characteristics of the system under different track conditions and train speeds are theoretically...

A novel design technique for low-loss waveguide crossing using the self-imaging properties of multimode interference (MMI) structures is presented. The technique exploits the observation that optical fields with a small 1/e width relative to that of the MMI structure in the image reformed region experience negligible propagation loss even in the absence of lateral guiding mechanism around the r...

Negative refraction of acoustic waves in a two-dimensional (2D) phononic crystal is studied by numerical simulation based on the finitedifference time-domain (FDTD) method. We calculate the phonon band structure of 2D phononic crystals, consisting of metal cylinders placed periodically in a liquid. By comparing several combinations of materials for metal cylinder and liquid, we analyze the depe...

The transport and bioavailability of sulphate in soils are significantly affected by adsorption reactions at the mineral–H2O interface. Therefore, an understanding of the mechanisms and kinetics of sulphate adsorption is of fundamental importance in soil chemistry. In this investigation, the binding geometries of bidentate bridging and monodentate sulphate complexes at the Fe (hydr)oxide–H2O in...

[1] Although mantle slabs ultimately drive plate motions, the mechanism by which they do so remains unclear. A detached slab descending through the mantle will excite mantle flow that exerts shear tractions on the base of the surface plates. This ‘‘slab suction’’ force drives subducting and overriding plates symmetrically toward subduction zones. Alternatively, cold, strong slabs may effectivel...

The mushroom body (MB), a conspicuous neuropil structure in the insect brain, is implicated in associative memory and in some aspects of motor control. Intrinsic neurons of the MB (Kenyon cells) extend dendrites into the calyx, and their axons run through the pedunculus and then bifurcate to form the alpha and the beta lobes. At the pedunculus and the lobes, Kenyon cells make synaptic connectio...

We have fabricated GaP two-dimensional photonic crystals (PCs) for terahertz (THz) wave generation by a reactive ion etching in Ar/Cl2 gas chemistries. We performed 75-mm-deep etching of GaP, in which Al2O3 layer is applied as a hard mask with its selectivity as high as 125. We demonstrated the THz-wave generation from the fabricated GaP slab waveguide with the PC structure as a cladding layer ...

In this paper we study and design quasi-2D optomechanical crystals, waveguides, and resonant cavities formed from patterned slabs. Two-dimensional periodicity allows for in-plane pseudo-bandgaps in frequency where resonant optical and mechanical excitations localized to the slab are forbidden. By tailoring the unit cell geometry, we show that it is possible to have a slab crystal with simultane...

The thermal structure of a generic subduction zone is investigated to elucidate the source region of subduction zone volcanics. The steady state thermal field is evaluated for a model subduction zone where the plates are prescribed by kinematic boundary conditions, such that the subducting slab induces a flow in the mantle wedge. The resulting model suggests that the oceanic crust of the downgo...

We present new tomographic models of the Nazca slab under South America from 6°S to 32°S, and from 95 km to lower mantle (895 km) depths. By combining data from 14 separate networks in the central Andes, we use finite-frequency teleseismic P-wave tomography to image the Nazca slab from the upper mantle into the mantle transition zone (MTZ) and the uppermost lower mantle on a regional scale. Our...