SiO₂ thin films are widely used in micro-electro-mechanical systems, integrated circuits and optical thin film devices. Tremendous efforts have been devoted to studying the preparation technology and optical properties of SiO₂ thin films, but little attention has been paid to their mechanical properties. Herein, the surface morphology of the 500-nm-thick, 1000-nm-thick and 2000-nm-thick SiO₂ thin films on the Si substrates was observed by atomic force microscopy. The hardnesses of the three SiO₂ thin films with different thicknesses were investigated by nanoindentation technique, and the dependence of the hardness of the SiO₂ thin film with its thickness was analyzed. The results showed that the average grain size of SiO₂ thin film increased with increasing film thickness. For the three SiO₂ thin films with different thicknesses, the same relative penetration depth range of ~0.4–0.5 existed, above which the intrinsic hardness without substrate influence can be determined. The average intrinsic hardness of the SiO₂ thin film decreased with the increasing film thickness and average grain size, which showed the similar trend with the Hall-Petch type relationship.

To identify the most accurate approach for constructing of the dynamic modulus master curves for warm mix crumb rubber modified asphalt mixtures and assess the feasibility of predicting the phase angle master curves from the dynamic modulus ones. The SM (Sigmoidal model) and GSM (generalized sigmoidal model) were utilized to construct the dynamic modulus master curve, respectively. Subsequently, the master curve of phase angle could be predicted from the master curve of dynamic modulus in term of the K-K (Kramers–Kronig) relations. The results show that both SM and GSM can predict the dynamic modulus very well, except that the GSM shows a slightly higher correlation coefficient than SM. Therefore, it is recommended to construct the dynamic modulus master curve using GSM and obtain the corresponding phase angle master curve in term of the K-K relations. The Black space diagram and Wicket diagram were utilized to verify the predictions were consistent with the LVE (linear viscoelastic) theory. Then the master curve of storage modulus and loss modulus were also obtained. Finally, the creep compliance and relaxation modulus can be used to represent the creep and relaxation properties of warm-mix crumb rubber-modified asphalt mixtures.

The misfit dislocations and strain fields at a Ge/Si heterostructure interface were investigated experimentally using a combination of high-resolution transmission electron microscopy and quantitative electron micrograph analysis methods. The type of misfit dislocation at the interface was determined to be 60° dislocation and 90° full-edge dislocation. The full-field strains at the Ge/Si heterostructure interface were mapped by using the geometric phase analysis (GPA) and peak pairs analysis (PPA), respectively. The effect of the mask size on the GPA and PPA results was analyzed in detail. For comparison, the theoretical strain fields of the misfit dislocations were also calculated by the Peierls-Nabarro and Foreman dislocation models. The results showed that the optimal mask sizes in GPA and PPA were approximately three tenths and one-tenth of the reciprocal lattice vector, respectively. The Foreman dislocation model with an alterable factor a = 4 can best describe the strain field of the misfit dislocation at the Ge/Si heterostructure interface.

The effects of ageing on the microstructure and dynamic rheological properties of three modified asphalt binders are investigated. The asphalt modifiers used comprise crumb rubber (CR), styrene–butadiene–styrene (SBS) block copolymer and a blend or combination of CR and SBS (CCR). To investigate the modified asphalts microstructure, scanning electron microscopy is applied, while for assessing rheological properties at a wide range of temperature, Bending Beam Rheometry and Dynamic Shear Rheometry are employed. Ageing of asphalt during construction and under service conditions is simulated using the rolling thin film oven test and the Pressurised Ageing Vessel procedures. It is observed that ageing makes all three modified asphalts harder, increases their resistance to deformation under high temperatures, and decreases their fatigue and cracking resistance at low temperatures. Comparatively, the CR maintains its bond with the asphalt better than the SBS and the CR-modified asphalt exhibits lower stiffness and lower degree of ageing under cold temperature, while it shows the highest resistance to high-temperature deformation and fatigue. On the contrary, the SBS-modified asphalt exhibits the worst performance in practically every respect compared to the CR- and CCR-modified asphalts.

To study the linear viscoelastic (LVE) of crumb rubber-modified asphalt mixtures before and after the warm mix additive was added methods of obtaining the discrete and continuous spectrum are presented. Besides, the relaxation modulus and creep compliance are constructed from the discrete and continuous spectrum, respectively. The discrete spectrum of asphalt mixtures can be obtained from dynamic modulus test results according to the generalized Maxwell model (GMM) and the generalized Kelvin model (GKM). Similarly, the continuous spectrum of asphalt mixtures can be obtained from the dynamic modulus test data via the inverse integral transformation. In this paper, the test procedure for all specimens was ensured to be completed in the LVE range. The results show that the discrete spectrum and the continuous spectrum have similar shapes, but the magnitude and position of the spectrum peaks is different. The continuous spectrum can be considered as the limiting case of the discrete spectrum. The relaxation modulus and creep compliance constructed by the discrete and continuous spectrum are almost indistinguishable in the reduced time range of 10⁻⁵ s–10³ s. However, there are more significant errors outside the time range, and the maximum error is up to 55%.