Applied Mechanics and Materials Vols. 236-237

Abstract: The fracture behavior of materials and structures are always caused by stress concentration near the defects in materials. This article describes the complex potential method for solving plane problems of quasicrystalline materials with defects. In order to prove effectiveness and success of the method, an example is given, and the results have very important significance in studying two-dimensional quasicrystals.

Abstract: he DPV UL19 protein encoded by UL19 gene was identified in our laboratory. In this article, we report some information about the structures and functions of this protein by using bioinformatics software or website online. The prediction indicated that DPV UL19 protein had no signal peptide and no transmembrane region, and could be a protein outside the membrane. It might contain many potential epitopes and functional sites. According to the prediction of 3D structure, a high reliability model was found in this protein. These works would be useful for further structural and functional studies of the DPV UL19 protein but experiments are needed to check the predicted results.

Abstract: This article describes a method to detect the position and speed in a rotary transformer pole AC synchronous motor. This method gives the pole position and velocity signal demodulation circuit and analyses the demodulation principle. After practical testing, this approach is reliable with high detection accuracy. Therefore, it is fully able to meet the needs of CNC machine tools with high performance in AC server system.

Abstract: The coefficient of retroreflection is considered as the most important parameter of retroreflective material, the value of which is tested by photopic detector now. In fact this material were usually used under mesopic vision condition, and through the test of retroreflective spectra, the mesopic spectral luminous efficiency V_mes(λ) and equivalent brightness were calculated. The result show that at different brightness the retroreflective light present unlike spectrum distribution, and white, blue material with higher retroreflection value under mesopic vision, red material own lower value, this phenomenon is more apparent with the decrease of brightness.

Abstract: The remote sensing measurement of the surface SiO₂ content has important geological significance .An empirical formula for estimate SiO₂ content was established based on the correlation between ASTER thermal infrared data and tested Si element from NITON sites in Abra, Australia. The average error of estimated SiO₂ content is about 15%. ASTER silica alteration derived from SiO₂ content has good indicative function to find galena. Combined with other prospecting factors as bouger gravity, transient electromagnetic and so on, three vision prospecting targets were optimized, which need more exploration works.

Abstract: A modified two-slit structure is provided to investigate surface plasmon (SP) interference. It’s based on a novel structure, implemented by adding a metal film on the input port of the T-shape slit. The affection of metal film for SP interference is investigated by simulation. Results show that the interference phenomenon can be more obvious with the metal film II than without it. With our structure, the added metal film can enhance transmission energy of SPs and improve interference effect. The results will give a theoretical guidance for development of nano-scale photonics devices.

Abstract: Ultra-violet, visible and near infrared (UV-VIS-NIR) spectroscopy combined with chemometrics was investigated for fast determination of soluble solids content (SSC) of tea beverage. In this study, a total of 120 tea samples with SSC range of 4.0-9.5 ºBrix were tested. Samples were randomly divided for calibration (n=90) and independent validation (n=30). Spectra were collected by a mobile fiber-type UV-VIS-NIR spectrophotometer in transmission mode with recorded wavelength range of 203.64-1128.05 nm. Various calibration approaches, i.e., principal components analysis (PCA), partial least squares (PLS) regression, least squares support vector machine (LSSVM) and back propagation artificial neural network (BPANN), were investigated. The combinations of PCA-BPANN, PCA-LSSVM, PLS-BPANN and PLS-LSSVM were also investigated to build calibration models. Validation results indicated that all these investigated models achieved high prediction accuracy. Especially, PLS-LSSVM achieved best performance with mean coefficient of determination (R2) of 0.99, root-mean-square error of prediction (RMSEP) of 0.12 and residual prediction deviation (RPD) of 15.16. This experiment suggests that it is feasible to measure SSC of tea beverage using UV-VIS-NIR spectroscopy coupled with appropriate multivariate calibration, which may allow using the proposed method for off-line and on-line quality supervision in the production of soft drink.

Abstract: Classification of grape seed species is a useful tool to obtain seeds with desired quality traits. This study aimed at rapidly and nondestructively discriminating four varieties of grape seeds using ultra violet, visible and near infrared (UV-VIS-NIR) spectroscopy with wavelength range of 210­1100 nm. A hundred twenty grape seed samples were divided for calibration (n=80) and validation (n=40). The spectra were subjected to a principal component analysis (PCA) with the leading 10 principal components (PCs) used to build calibration models. The obtained PCs were treated by linear discriminant analysis (LDA), artificial neural network (ANN) and support vector machine (SVM) to build various discrimination models. Validation results showed that the PC-LDA model developed for the full range of UV-VIS-NIR achieved better performance than those developed for partial wavelengths, i.e. UV, VIS, NIR, UV-VIS, and VIS-NIR. The PC-LDA model with 8 PCs achieved best performance with 100% discrimination accuracy. This experiment suggests that the UV-VIS-NIR spectroscopy coupled with PC-LDA calibration method is promising for the nondestructive discrimination of grape seed varieties.

Abstract: The corrosion characteristics of 2205 duplex stainless steel in high- temperature and high-pressure (HT and HP) environments containing H2S/CO2 are investigated in this paper. After corroded 720 hours in the condition of 3.5 MPa H2S, 3.5 MPa CO2, 205°C, 15% NaCl and a sulfide content of 3g/L, one layer of comparably thick corrosion product are formed on the surface of the specimens. The corrosion products, which are relatively porous, lose its protection to the matrix. Lots of pitting are found on the surface of the steel and intercrystalline fracture and transcrystalline fracture are generated in the bottom of the pitting, which indicates its high sensitivity to stress corrosion crack (SSC). Also, the phenomenon of selective corrosion, a priority corrosion of α phase and minor corrosion or non-corrosion of γ phase, is observed after the corrosion process.

Abstract: The formation and structure properities of N-isopropyl base acrylamide (PNIPAm)gels with different synthetic temperatures, monomer concentrations and crosslinker concentrations were discussed, and the application of intelligent glass was researched. The results show : The synthesized PNIPAm gel is transparent and elastic, when the temperature is at 10 °C -20 °C, monomer concentration is 10%, crosslinker concentration is 5%. With the increasing of polymerization temperature, monomer concentration, and crosslinker concentration, the temperature of color change is both 32 °C,leading to the decrease of transmittance ratio, the readuce of temperature sensitivity. Synthesized PNIPAm gel was put in the glass of interlayer, which plays a good shading result .