High‐Quality Stereo Depth Map Generation Using Infrared Pattern Projection

In this paper, we present a method for obtaining a highquality 3D depth. The advantages of active pattern projection and passive stereo matching are combined and a system is established. A diffractive optical element (DOE) is developed to project the active pattern. Cross guidance (CG) and auto guidance (AG) are proposed to perform the passive stereo matching in a stereo image in which a DOE pattern is projected. When obtaining the image, the CG emits a DOE pattern periodically and consecutively receives the original and pattern images. In addition, stereo matching is performed using these images. The AG projects the DOE pattern continuously. It conducts cost aggregation, and the image is restored through the process of removing the pattern from the pattern image. The ground truth is generated to estimate the optimal parameter among various stereo matching algorithms. Using the ground truth, the optimal parameter is estimated and the cost computation and aggregation algorithm are selected. The depth is calculated and bad‐pixel errors make up 4.45% of the non‐occlusion area.     

Effect of a Mo back contact on Na diffusion in CIGS thin film solar cells

We investigated the effects of the microstructures of molybdenum (Mo) back contacts on sodium (Na) diffusion from sodalime glass into a Cu(In,Ga)Se₂ (CIGS) absorber as a function of the sputter deposition pressure during preparation of the Mo contact layer. The surface characteristics of the Mo layers more significantly affected the diffusion of Na ions into the CIGS compared with the Mo bulk. The Na ion diffusion depended strongly on the amount of oxygen adsorbed onto the Mo layer surfaces. Secondary ion mass spectroscopy results showed that Na accumulated in a layer (Na–O compound) on the Mo surface (the CIGS/Mo interface), and this layer served as a primary source of Na ions diffusing into the CIGS. A trilayered Mo back contact structure was prepared in an effort to decouple the functions of electrical conductance and Na diffusion. The ability of this surface to control the Na concentration in a CIGS absorber is discussed. Copyright © 2012 John Wiley & Sons, Ltd.     

High-throughput volumetric adaptive optical imaging using compressed time-reversal matrix

Deep-tissue optical imaging suffers from the reduction of resolving power due to tissue-induced optical aberrations and multiple scattering noise.Reflection matrix approaches recording the maps of backscattered waves for all the possible orthogonal input channels have provided formidable solutions for removing severe aberrations and recovering the ideal diffraction-limited spatial resolution without relying on fluorescence labeling and guide stars.However,measuring the full input–output response of the tissue specimen is time-consuming,making the real-time image acquisition difficult.Here,we present the use of a time-reversal matrix,instead of the reflection matrix,for fast high-resolution volumetric imaging of a mouse brain.The time-reversal matrix reduces two-way problem to one-way problem,which effectively relieves the requirement for the coverage of input channels.Using a newly developed aberration correction algorithm designed for the time-reversal matrix,we demonstrated the correction of complex aberrations using as small as 2%of the complete basis while maintaining the image reconstruction fidelity comparable to the fully sampled reflection matrix.Due to nearly 100-fold reduction in the matrix recording time,we could achieve real-time aberration-correction imaging for a field of view of 40×40µm²(176×176 pixels)at a frame rate of 80 Hz.Furthermore,we demonstrated high-throughput volumetric adaptive optical imaging of a mouse brain by recording a volume of 128×128×125µm³(568×568×125 voxels)in 3.58 s,correcting tissue aberrations at each and every 1µm depth section,and visualizing myelinated axons with a lateral resolution of 0.45µm and an axial resolution of 2µm.     

Bonding features and associated mechanisms in kinetic sprayed titanium coatings

This study aims to explore the bonding features and mechanisms present in kinetic spray coatings of commercially pure titanium (CP-Ti) by linking experimental observations with finite element modeling for the purpose of optimizing the deposition process. The numerically predicted deformation features and interface thermomechanical responses of the particles adequately elucidate the deposition characteristics for different impact conditions. The formation of a porous coating by local bonding at relatively low velocity and of a very dense coating accompanied by interfacial melting at higher velocity resulted from deformation localization at high strain rates due to the relatively higher adiabacity as compared with other materials, which is one of the unique bonding mechanisms in CP-Ti. The enhanced thermal boost-up zone due to thermally accelerated adiabatic shear instability by powder preheating resulted in improved coating properties, and is essential for the optimization of economical coating processes.     

Synthesis and characterization of Cu3N-WC nanocomposite films prepared by direct current magnetron sputtering

Cu₃N-WC films were synthesized on an arc ion plated TiN_x interlayer by direct current magnetron sputtering. The Cu₃N-WC films, composed of columnar WC crystals 3-5 nm in size and amorphous Cu₃N phases, were grown using the layer-plus-island mode. Deposition rate of Cu₃N-WC films declined from 11.7 to 7.5 nm/min when the WC target power increased from 200 to 400 W because the Cu target was poisoned by the diffusion of WC molecules. Nano-indentation testing results showed that the highest measure of hardness of Cu₃N-WC films was up to ∼ 41 GPa and the H³/E^?2 value of the Cu₃N-WC_47.4 was around 0.41 GPa, indicating the excellent plastic deformation resistance of the film. Incorporation of the soft lubricant Cu₃N phase and the uniform distribution of WC hard phases resulted in significant improvements in friction coefficient and wear resistance. As such, Cu₃N-WC films have a good potential in future wear applications.     

Electrical Properties of the Ta-RuO2 Diffusion Barrier for High-Density Memory Devices

The electrical properties of a Ta layer prepared with and without RuO₂ addition were investigated. The Ta + RuO₂/TiSi₂/poly-Si/SiO₂/Si contact system exhibited lower total resistance and ohmic characteristics up to 800°C. Meanwhile, the Ta/TiSi₂/poly-Si/SiO₂/Si contact system showed higher total resistance and nonohmic behavior after annealing at 650°C, attributed to the oxidation of both Ta and TiSi₂ layers. In the former case, a Ta + RuO₂ diffusion barrier showed an amorphous Ta microstructure and embedded RuO _x nanocrystals in the as-deposited state. The conductive RuO₂ crystalline phase in the Ta + RuO₂ film was formed by reaction between the nanocrystalline RuO _x and oxygen indiffused from air during annealing. When the Ta layer was deposited with RuO₂ addition, therefore, both the electrical properties and the oxidation resistance of the Ta + RuO₂ diffusion barrier were better than those of TiN, TaN, and Ta-Si-N barriers.