Laser-induced coloration on metal surfaces has important applications in product identification, enhancing styles and aesthetics. The color generation is the result of controlled surface oxidation ...during laser beam interaction with the metal surfaces. In this study, we aim to obtain in-depth understanding of the oxide formation process when an UV laser beam interacts with stainless steel in air. The oxide layer is analysed by means of optical microscopy, scanning electron microscopy (SEM) and time-of-flight secondary ion mass spectrometer (TOF-SIMS). TOF-SIMS results clearly show the formation of duplex oxide structures. The duplex structure includes an inner layer of Cr oxide solution and an outer layer of Fe oxide solution. The oxide layer thickness increased as the results of Fe diffusion to surface during multiple laser scanning passes.
The dependence of physical properties of the electrically charged monopole–antimonopole pair (MAP) solutions in the Higgs self-coupling constant is previously investigated. In this paper we study the ...three-poles monopole–antimonopole chain (MAC) solutions. The study includes ϕ-winding number n=2,3, and 4. For the case of n=2, no bifurcation and geometrical transition is detected for the interval of the study. For the case of n=3, two geometrical transitions happen along the fundamental solution. Also two bifurcations and one joining point is detected for the interval of study. The case of n=4 includes one bifurcation. There is also a geometrical transition along the fundamental solution and two transitions along the Higher energy bifurcating branch. This study implies that during some specific kind of geometrical transition, a magnetic and electric charge transition occurs for the pole which is located at the origin.
A theoretical framework based on the concepts and tools of nonlinear dynamical systems is advanced to account for both the persistent and transitory changes traditionally shown for the learning and ...development of motor skills. The multiple time scales of change in task outcome over time are interpreted as originating from the system's trajectory on an evolving attractor landscape. Different bifurcations between attractor organizations and transient phenomena can lead to exponential, power law, or
S
-shaped learning curves. This unified dynamical account of the functions and time scales in motor learning and development offers several new hypotheses for future research on the nature of change in learning theory.
The protein encoded by the first gene of the triple gene block (TGBp1) of potexviruses is required for movement of the viruses. It has been reported that single Arg-->Ala substitutions at position ...11, 16 or 21 of TGBp1 of Bamboo mosaic virus (BaMV) eliminate its RNA-binding activity, while substitutions at position 16 or 21 only affect its NTPase activity (Liou et al., Virology 277, 336-344, 2000). However, it remains unclear whether these Arg-->Ala substitutions also affect the movement of BaMV in plants. To address this question, six mutants of BaMV, each containing either a single- or a double-alanine substitution at Arg-11, Arg-16 and Arg-21 of TGBp1, were constructed and used to infect Chenopodium quinoa and Nicotiana benthamiana. We found that all of the BaMV mutants were able to replicate in protoplasts of N. benthamiana. However, only the mutant with an Arg-11-->Ala substitution in TGBp1 remained capable of movement from cell to cell in plants. Mutants with Arg-16, Arg-21 or both Arg-16 and Arg-21 of TGBp1 replaced with alanine were defective in virus movement. This defect was suppressed when a wild-type TGBp1 allele was co-introduced into the cells using a novel satellite replicon. The ability to trans-complement the movement defect by the wild-type TGBp1 strongly suggests that the Arg-->Ala substitution at position 16 or 21 of TGBp1, which diminishes the RNA-binding and NTPase activities of TGBp1, also eliminates the capability of BaMV to move from cell to cell in host plants.
In the present work, pure forsterite (Mg
2
SiO
4
) powder was successfully synthesised via ball milling and subsequent heat treatment as an evident from X-ray diffraction analysis. The synthesised ...powder were formed by powder agglomerates that were made up of loosely packed fine particles. Then, the forsterite green bodies were sintered at 1200 and 1400°C with two different ramp rates (2 and 10°C per minute) via conventional pressureless sintering. No decomposition of forsterite phase was observed at both ramp rates. This study revealed that lower ramp rate (2°C per minute) possessed minor improvement on the mechanical properties only at lower sintering temperature (1200°C), whereas 10°C per minute ramp rate gave a significant enhancement on the mechanical properties of forsterite at 1400°C. A high fracture toughness of ∼4·9 MPa m
1/2
and Vickers hardness of ∼7·1 GPa were obtained for forsterite samples sintered at 1400°C with a ramp rate of 10°C per minute.
Raman spectroscopy is a molecular vibrational spectroscopic technique that is capable of optically probing the biomolecular changes associated with diseased transformation. The purpose of this study ...was to explore near-infrared (NIR) Raman spectroscopy for identifying dysplasia from normal gastric mucosa tissue. A rapid-acquisition dispersive-type NIR Raman system was utilised for tissue Raman spectroscopic measurements at 785 nm laser excitation. A total of 76 gastric tissue samples obtained from 44 patients who underwent endoscopy investigation or gastrectomy operation were used in this study. The histopathological examinations showed that 55 tissue specimens were normal and 21 were dysplasia. Both the empirical approach and multivariate statistical techniques, including principal components analysis (PCA), and linear discriminant analysis (LDA), together with the leave-one-sample-out cross-validation method, were employed to develop effective diagnostic algorithms for classification of Raman spectra between normal and dysplastic gastric tissues. High-quality Raman spectra in the range of 800-1800 cm(-1) can be acquired from gastric tissue within 5 s. There are specific spectral differences in Raman spectra between normal and dysplasia tissue, particularly in the spectral ranges of 1200-1500 cm(-1) and 1600-1800 cm(-1), which contained signals related to amide III and amide I of proteins, CH(3)CH(2) twisting of proteins/nucleic acids, and the C=C stretching mode of phospholipids, respectively. The empirical diagnostic algorithm based on the ratio of the Raman peak intensity at 875 cm(-1) to the peak intensity at 1450 cm(-1) gave the diagnostic sensitivity of 85.7% and specificity of 80.0%, whereas the diagnostic algorithms based on PCA-LDA yielded the diagnostic sensitivity of 95.2% and specificity 90.9% for separating dysplasia from normal gastric tissue. Receiver operating characteristic (ROC) curves further confirmed that the most effective diagnostic algorithm can be derived from the PCA-LDA technique. Therefore, NIR Raman spectroscopy in conjunction with multivariate statistical technique has potential for rapid diagnosis of dysplasia in the stomach based on the optical evaluation of spectral features of biomolecules.
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