Distribution equilibria of Pb and Cu between CaO-SiO2-Al2O3 melts and liquid copper

The distribution equilibria of lead and copper between CaO-SiO₂-Al₂O₃ melts and liquid copper were measured at 1623 K under a controlled H₂-CO₂ atmosphere. The distribution ratios were plotted against the oxygen partial pressure, and reasonable oxide forms dissolved in the melts were estimated from the slopes of the plots. The activity coefficients of lead oxide (PbO) and cuprous oxide (CuO_0.5) increased with increasing slag basicity, defined by X _CaO/X _SiO2. The temperature dependence of the activity coefficients of lead oxide and cuprous oxide was also measured.     

Fully automated on-chip imaging flow cytometry system with disposable contamination-free plastic re-cultivation chip

We have developed a novel imaging cytometry system using a poly(methyl methacrylate (PMMA)) based microfluidic chip. The system was contamination-free, because sample suspensions contacted only with a flammable PMMA chip and no other component of the system. The transparency and low-fluorescence of PMMA was suitable for microscopic imaging of cells flowing through microchannels on the chip. Sample particles flowing through microchannels on the chip were discriminated by an image-recognition unit with a high-speed camera in real time at the rate of 200 event/s, e.g., microparticles 2.5 μm and 3.0 μm in diameter were differentiated with an error rate of less than 2%. Desired cells were separated automatically from other cells by electrophoretic or dielectrophoretic force one by one with a separation efficiency of 90%. Cells in suspension with fluorescent dye were separated using the same kind of microfluidic chip. Sample of 5 μL with 1 × 10(6) particle/mL was processed within 40 min. Separated cells could be cultured on the microfluidic chip without contamination. The whole operation of sample handling was automated using 3D micropipetting system. These results showed that the novel imaging flow cytometry system is practically applicable for biological research and clinical diagnostics.     

High-resolution three-dimensional scanning transmission electron microscopy characterization of oxide-nitride-oxide layer interfaces in Si-based semiconductors using computed tomography

Oxide-nitride-oxide (ONO) layer structures are widely used for charge storage in flash memory devices. The ONO layer interfaces should be as flat as possible, so measurement of the nanoscale roughness of those interfaces is needed. In this study, quantification of an ONO film from a commercially available flash memory device was carried out with a pillar-shaped specimen using scanning transmission electron microscopy (STEM) and computed tomography. The ONO area contained only low Z- and low STEM-contrast materials, which makes high-quality reconstruction difficult. The optimum three-dimensional reconstruction was achieved with an STEM annular dark-field detector inner collection angle of 32?mrad, a sample tilt range from -78° to +78° and 25 iterations for the simultaneous iterative reconstruction technique.     

Convergent-beam electron diffraction

This paper reviews the convergent-beam electron diffraction (CBED) technique. Point- and space-group determination methods of ordinary crystals are described, along with an example of the determination method for Sr?Ru?O?. The symmetry determination of one-dimensionally incommensurate crystals and quasicrystals is explained. The large-angle CBED technique, which is indispensable for lattice defect and lattice strain analysis, is also described. A real procedure for lattice strain analysis is provided, using an example of a multilayer Si?-xGe(x)/Si material. A nanometer-scale crystal structure refinement method and charge density and crystal potential determination method by CBED are briefly described.     

Simplified homography matrix for a large-scale camera array system

We want to use a large-scale camera array system in which each camera is placed at the desired position to photograph a subject and later render images of the subject viewed from various directions or render images for a three-dimensional display. The homography matrix for each camera should be calculated in advance to correct the captured images. In the case that each camera is physically facing toward the subject as precisely as possible but the captured image still includes geometrical distortion, if the expected error in the deviations from the ideal directions is assumed to be the zero vector, the homography matrix of each camera can be easily obtained.     

ph‐Dependent Synthesis of Pepsin‐Mediated Gold Nanoclusters with Blue Green and Red Fluorescent Emission

This report demonstrates the first pH‐dependent synthesis of pepsin‐mediated gold nanoclusters (AuNCs) with blue‐, green‐, and red‐fluorescent emission from Au₅ (Au₈), Au₁₃, and Au₂₅, respectively. Pepsin is a gastric aspartic proteinase (molecular weight, 34 550 g/mol) that plays an integral role in the digestive process of vertebrates. It was found that the pH of the reaction solution was critical in determining the size of Au NCs (i.e., the number of gold atoms of AuNCs). Interestingly, enzyme function of pepsin contributes to the formation of these AuNCs. The photo‐stability of the Au₂₅ (or Au₁₃) NCs is much higher than that of Au₅NCs (i.e., Au₂₅ ～ Au₁₃ > > Au₅). The pepsin‐mediated Au₂₅NCs were also found to be useful as fluorescent sensors for the detection of Pb²⁺ ions by enhanced fluorescence and the detection of Hg²⁺ ions by fluorescence quenching. Although the detailed formation mechanisms of these AuNCs require further analysis, the synthetic route using proteinase demonstrated here is promising for preparing new types of fluorescent metal nanoclusters for application in catalysis, optics, biological labeling, and sensing.     

Comparison of hydrogen isotope retention and irradiation damage behaviors in tungsten and SS-316 with simultaneous C+–D2+ implantation

Behaviors of hydrogen isotope retention and damages in tungsten and SS-316 with simultaneous C⁺–D₂⁺ implantation were compared to those with only D₂⁺ implantation using X-ray photoelectron spectroscopy (XPS), Thermal desorption spectroscopy (TDS), glow discharge-optical emission spectroscopy (GD-OES) and Transmission electron microscopy (TEM).The total D retention for SS-316 with only D₂⁺ implantation was about 45% as large as that for tungsten. The D retention for simultaneous C⁺–D₂⁺ implanted tungsten and SS-316 clearly increased as a factor of 1.7, which is almost the same among these samples. The density of dislocation loops was enhanced by the simultaneous C⁺–D₂⁺ implantation, indicating the D trapping site would be produced by C⁺ implantation. As for the D desorption temperature, small shift toward lower temperature side was found for SS-316 compared to tungsten, indicating the D trapping energy by dislocation loops and grain boundary for SS-316 is lower than that for tungsten.     

Elastic properties and Vickers hardness of optically transparent glass-ceramics with fresnoite Ba2TiSi2O8 nanocrystals

Optically transparent glass-ceramics (40BaO-20TiO₂-40SiO₂ (mol%)) consisting of nonlinear optical fresnoite Ba₂TiSi₂O₈ (BTS) nanocrystals (diameter: 100-200 nm) are fabricated, and their elastic properties and deformation behavior are examined as a function of the volume fraction (f) of BTS nanocrystals using cube resonance and Vickers indentation techniques. The elastic properties such as Young's modulus (E) increases linearly with increasing the volume fraction of nanocrystals, e.g., E = 84 GPa for f = 0% (glass) to E = 107 GPa for f = 54.5%. The Vickers hardness (H_v) and indentation fracture toughness (K_c) increase from 5.0 to 6.0 GPa for H_v and 0.48 to 1.05 MPa m^−1/2 for K_c with increasing the volume fraction (from f = 0% to f = 54.5%), but they do not change linearly against the volume fraction of nanocrystals. It is suggested that BTS nanocrystals themselves induce a high resistance against deformation during Vickers indenter loadings.