Intrinsic Electronic Structure and Nodeless Superconducting Gap of YBa2Cu3O7−δ\mathrm{YBa_{2} Cu_{3} O_{7-\delta} } Observed by Spatially-Resolved Laser-Based Angle Resolved Photoemission Spectroscopy

The spatially-resolved laser-based high resolution ARPES measurements have been performed on the optimally-doped $\mathrm{YBa_{2} Cu_{3} O_{7-\delta} }$ (Y123) superconductor. For the first time, we found the region from the cleaved surface that reveals clear bulk electronic properties. The intrinsic Fermi surface and band structures of Y123 are observed. The Fermi surface-dependent and momentum-dependent superconducting gap is determined which is nodeless and consistent with the d+is gap form

Electronic Origin of High-Tc Maximization and Persistence in Trilayer Cuprate Superconductors

In high temperature cuprate superconductors, it was found that the superconducting transition temperature Tc depends on the number of CuO2 planes (n) in the structural unit and the maximum Tc is realized in the trilayer system (n=3). It was also found that the trilayer superconductors exhibit an unusual phase diagram that Tc keeps nearly constant in the overdoped region which is in strong contrast to the Tc decrease usually found in other cuprate superconductors. The electronic origin of the Tc maximization in the trilayer superconductors and its high Tc persistence in the overdoped region remains unclear. By taking high resolution laser-based angle resolved photoemission (ARPES) measurements, here we report our revelation of the microscopic origin of the unusual superconducting properties in the trilayer superconductors. For the first time we have observed the trilayer splitting in Bi2Sr2Ca2Cu3O10+d (Bi2223) superconductor. The observed Fermi surface, band structures, superconducting gap and the selective Bogoliubov band hybridizations can be well described by a three-layer interaction model. Quantitative information of the microscopic processes involving intra- and interlayer hoppings and pairings are extracted. The electronic origin of the maximum Tc in Bi2223 and the persistence of the high Tc in the overdoped region is revealed. These results provide key insights in understanding high Tc superconductivity and pave a way to further enhance Tc in the cuprate superconductors

An Assessment of the Impact of Temperature Rise Due to Climate Change on Asphalt Pavement in China

In the global warming context, understanding the impact of temperature rise on asphalt pavement is the basis for making adaptation strategies. An approach based on historical climate data and pavement performance models was employed to assess the potential impact of temperature rise on asphalt pavement in China. It is shown that permanent deformation is one sensitive aspect of asphalt pavement performance, which increased on average by 20.70% from 1992 to 2019. Another one is low-temperature cracking, which decreased by 20.99% from 1970 to 1997, but has remained almost unchanged since 1997. Global mean surface temperature anomalies of 1.5 °C and 2.0 °C will increase the permanent deformation of asphalt pavement by 18.63% and 36.71%, respectively, compared to 2019. Global warming is bringing serious challenges to the structure and material design of asphalt pavement due to the increasing service temperature range

Influences of Interface Properties on the Performance of Fiber-Reinforced Asphalt Binder

This paper presents an experimental study about the influence of interfacial properties on the performance of fiber-reinforced asphalt. In this study, four types of fiber including one fiber-reinforced plastic (FRP), two lignin fibers, and one basalt fiber are used, and also four types of asphalt: Asphalt No. 90, asphalt No. 70, one styrene-butadiene-styrene (SBS) modified asphalt, and asphalt rubber are used. The surface energy parameters of various asphalts and fibers and the shear strength of various fiber-reinforced asphalts are measured. On the basis of these measurements, the influences of surface properties of asphalt and fiber on the performance of fiber-reinforced asphalt are analyzed. The results show that the shear strength of asphalt binder can be significantly increased by adding fibers, and the reinforcement effect is closely related to the types of asphalt and fiber. It was discovered, for the same asphalt, that the basalt fiber has the best reinforcement effect, followed by the two lignin fibers, and the FRP. For the same fiber, asphalt rubber was the most reinforced, followed by the SBS modified asphalt, asphalt No. 70 and asphalt No. 90. It was also discovered, for the same asphalt, the higher the surface energy of the fiber, the better the fiber reinforcement effect. The analysis indicates a good correlation between the work of adhesion between asphalt and fiber and the effect of fiber reinforcement. The results can be used as a basis for the selection of the proper fiber-asphalt combination to improve fiber reinforcement effects

An Assessment of the Impact of Temperature Rise Due to Climate Change on Asphalt Pavement in China

In the global warming context, understanding the impact of temperature rise on asphalt pavement is the basis for making adaptation strategies. An approach based on historical climate data and pavement performance models was employed to assess the potential impact of temperature rise on asphalt pavement in China. It is shown that permanent deformation is one sensitive aspect of asphalt pavement performance, which increased on average by 20.70% from 1992 to 2019. Another one is low-temperature cracking, which decreased by 20.99% from 1970 to 1997, but has remained almost unchanged since 1997. Global mean surface temperature anomalies of 1.5 °C and 2.0 °C will increase the permanent deformation of asphalt pavement by 18.63% and 36.71%, respectively, compared to 2019. Global warming is bringing serious challenges to the structure and material design of asphalt pavement due to the increasing service temperature range

Review on Load Transfer Mechanisms of Asphalt Mixture Meso-Structure

Asphalt mixture is a skeleton filling system consisting of aggregate and asphalt binder. Its performance is directly affected by the internal load transfer mechanism of the skeleton filling system. It is significant to understand the load transfer mechanisms for asphalt mixture design and performance evaluation. The objective of this paper is to review the research progress of the asphalt mixture load transfer mechanism. Firstly, this paper summarizes the test methods used to investigate the load transfer mechanism of asphalt mixtures. Then, an overview of the characterization of load transfer mechanism from three aspects was provided. Next, the indicators capturing contact characteristics, contact force characteristics, and force chain characteristics were compared. Finally, the load transfer mechanism of asphalt mixtures under different loading conditions was discussed. Some recommendations and conclusions in terms of load transfer mechanism characterization and evaluation were given. The related work can provide valuable references for the study of the load transfer mechanism of asphalt mixtures

Review on Load Transfer Mechanisms of Asphalt Mixture Meso-Structure

Asphalt mixture is a skeleton filling system consisting of aggregate and asphalt binder. Its performance is directly affected by the internal load transfer mechanism of the skeleton filling system. It is significant to understand the load transfer mechanisms for asphalt mixture design and performance evaluation. The objective of this paper is to review the research progress of the asphalt mixture load transfer mechanism. Firstly, this paper summarizes the test methods used to investigate the load transfer mechanism of asphalt mixtures. Then, an overview of the characterization of load transfer mechanism from three aspects was provided. Next, the indicators capturing contact characteristics, contact force characteristics, and force chain characteristics were compared. Finally, the load transfer mechanism of asphalt mixtures under different loading conditions was discussed. Some recommendations and conclusions in terms of load transfer mechanism characterization and evaluation were given. The related work can provide valuable references for the study of the load transfer mechanism of asphalt mixtures

The Development and Field Evaluation of an IoT System of Low-Power Vibration for Bridge Health Monitoring

Bridge safety is important for the safety of vehicles and pedestrians. This paper presents a study on the development of a low-power wireless acceleration sensor and deployment of the sensors on a wireless gateway and cloud platform following the Internet of Things (IoT) protocols for bridge monitoring. The entire system was validated in a field test on the Chijing bridge in Shanghai. Field evaluations indicated that the developed IoT bridge monitoring system could achieve the functions of real-time data acquisition, transmission, storage and analytical processing to synthesize safety information of the bridge. The demonstrated system was promising as a complete, practical, readily available, low-cost IoT system for bridge health monitoring