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  • Author: Zhiqiang Lin x
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Abstract

Dy3+ doped antimony phosphate (ZASP) glasses are synthesized and the specificity of the luminescence behavior is demonstrated. Different from the conventional long-wave ultraviolet (UVA) exciting cases, the excitable area of Dy3+ doped ZASP glasses is extended to high-energy ultraviolet radiation including medium-wave ultraviolet (UVB) and short-wave ultraviolet (UVC) spectral regions. The quantum efficiency for 4F9/2 level of Dy3+ in low- and medium-concentration Dy2O3 doping cases reaches 95.0 % and 66.7 %, respectively, confirming the emission effectiveness from Dy3+ in ZASP glasses. The values of energy-transfer probability (P) have obvious difference while using 340 nm and 540 nm as monitoring wavelengths, so asthe energy-transfer efficiencies (η), which are related to the energy-transfer processes from discrepant Sb3+ donors to Dy3+ acceptors, were in-equivalent. The effective excitability of high-energy ultraviolet radiation illustrates that Dy3+ doped ZASP glasses are a promising candidate in developing visible light sources, display devices and tunable visible lasers.

Abstract

The influence of ZnO substitution by 0–12 wt.% Na2O on the properties of ZnO-Sb2O3-P2O5-Na2O glasses has been investigated. The structure and properties of the glasses with the composition of (13.86-x)ZnO-57.93Sb2O3-28.21P2O5−x Na2O (x = 0–12 wt.%) were characterized by infrared spectra (IR), X-ray diffraction and differential thermal analysis (DTA). The results of IR indicated an increase in the intensity of symmetric vibrations of P-O-P bond, which was confirmed by the improvement of water durability with the increasing amount of Na2O in the range of 0–10 wt.%. Substitution of 10 wt.% Na2O led to the weight loss of the glass to 5.93 mg/cm−2 after immersion in deionized water at 50 °C for 24 h. The results of XRD showed that the ability of crystallization decreased, indicating the good thermal stability of the glass. The glass containing 8 wt.% Na2O had the best properties in every respect and might be an alternative to lead based glasses for the applications, providing further composition improvement.

Abstract

SrO–Sb2O3–P2O5 glass system was prepared by high temperature melting method. The effects of Sb2O3 and P2O5 content on the structure, thermal behavior and chemical durability of the glasses were studied by infrared spectrometer, thermal dilatometer, differential thermal analyzer and constant temperature water bath heating. It can be concluded that the characteristic temperatures of the glasses increased firstly and then decreased with the increasing of Sb2O3 content, whereas the tendency of the coefficient of thermal expansion (CTE) varied inversely. The crystallization ability of the glasses was significantly increased and the water resistance was reduced for Sb2O3 content of 35 mol % and 40 mol %. The glasses with 20 mol %, 25 mol % and 30 mol % Sb2O3 showed better performance in every respect than the others and the glasses containing 25 mol % Sb2O3, characterized by the best performance, can be chosen as host glasses for further research.

Abstract

The most attractive structural feature of the three-dimensional (3D) angle-interlock woven structure is that the straight weft yarns are bundled by the undulated warp yarns, which induces the overall good structural stability and a stable fabric structure. Thus the 3-D angle-interlock woven composite (3DAWC) prepared by the vacuum-assisted resin transfer molding (VARTM) curing process has excellent mechanical properties by using the fabric and epoxy resin as the reinforcement and matrix, respectively. The low-velocity impact damage properties of the composites under different drop-weight energies (70, 80, and 100 J) were tested experimentally. The load–displacement curves, energy–time curves, and the ultimate failure modes were obtained to analyze the performance of resistance to low-velocity impact, as well as the impact energy absorption effect and failure mechanism, especially the structural damage characteristics of the 3DAWC subjected to the low-velocity impact of drop weight. By analyzing the obtained experimental results, it is found that the fabric reinforcement is the primary energy absorption component and the impact energy mainly propagates along the longitudinal direction of the yarns, especially the weft yarn system, which is arranged in a straight way. In addition, as the impact energy increases, the energy absorbed and dissipated by the composite increases simultaneously. This phenomenon is manifested in the severity of deformation and damage of the material, i.e., the amount of deformation and size of the damaged area.

Abstract

Glasses composed of ternary components (35 – x)Sb2O3–xBi2O3–65P2O5 (0 ⩽ x ⩽ 20 mol%) have been prepared and investigated as a potential alternative to lead-free glass for low temperature applications. Their structural properties were studied by Infrared Spectroscopy IR and Differential Thermal Analysis DTA. Results from the IR showed that Sb3+ and Bi3+ were responsible for glass network structure, which was supported by the diversification of density ρ and molar volume Vm with an increasing amount of Bi2O3. Glass transition temperature Tg, thermal stability, and coefficient of thermal expansion increased after substitution of Bi2O3 for Sb2O3 within the range of 0 mol% to 20 mol%. The water durability decreased and then increased; it could be attributed to the corrosion resistant P–O–Sb bonds. A typical sample of 25Sb2O3–10Bi2O3–65P2O5 possesses excellent properties and can be a promising candidate for further applications.