The utilization of reclaimed asphalt pavement (RAP) could reduce the cost of pavements containing epoxy polymer (EP) materials. This study was aimed at improving the homogeneity of an EP-reclaimed asphalt mixtures (ERAMs) at both the micro- and meso-scale to provide a reference for an ERAM production process. At the microscale, nanoindentation tests were conducted to characterize the diffusion between the EP and aged asphalt mastic.
View Article and Find Full Text PDFConventionally, to produce a linear motion, one motor's stator is employed to drive one runner moving forward or backward. So far, there is almost no report of one electromechanical motor or piezoelectric ultrasonic motor that can directly generate two symmetrical linear motions, while this function is desired for precise scissoring and grasping in the minimally invasive surgery field. Herein, we report a brand-new symmetric-actuating linear piezoceramic ultrasonic motor capable of generating symmetrical linear motions of two outputs directly without additional mechanical transmission mechanisms.
View Article and Find Full Text PDFA series of double [4]helicene-like naphthobisbenzothiophene diimides and their thienyl-S,S-dioxidized derivatives are synthesized via MoCl-catalyzed cyclization and -CPBA-mediated oxidation reactions. The functional five-membered ring diimides show a helicene-like geometry, strong solid-state fluorescence, and deep LUMO of -4.37 eV.
View Article and Find Full Text PDFIn this study, brain imaging data from functional near-infrared spectroscopy (fNIRS) associated with skin conductance response (SCR), heart rate (HR), and reaction time (RT) were combined to determine if the combination of these indicators could improve the efficiency of deception detection in concealed information test (CIT). During the CIT, participants were presented with a series of names and cities that served as target, probe, or irrelevant stimuli. In the guilty group, the probe stimuli were the participants' own names and hometown cities, and they were asked to deny this information.
View Article and Find Full Text PDFPiezoelectric ceramic devices, which utilize multifarious vibration modes to realize electromechanical coupling and energy conversions, are extensively used in high-technological fields. However, the excitation of basic modes is mainly subjected to natural eigenfrequency of ceramic devices, which is related to the structure and material parameters. Herein, inspired by metamaterial theory, a programmable, 3D ordered structure with piezoceramic strain units (3D OSPSU) is developed to artificially generate basic modes in a broad frequency band other than only in narrow eigenfrequency.
View Article and Find Full Text PDFIn order to obtain more accurate parameters required for the simulation of asphalt mixtures in the discrete element method (DEM), this study carried out a series of cross-functional asphalt mixture experiments to obtain the DEM simulation meso-parameters. By comparing the results of simulation and actual experiments, a method to obtain the meso-parameters of the DEM simulation was proposed. In this method, the numerical aggregate profile was obtained by X-ray CT scanning and the 3D aggregate model was reconstructed in MIMICS.
View Article and Find Full Text PDFContinual precision actuations with nanoscale resolution over large ranges have extensive requirements in advanced intelligent manufacturing and precise surgical robots. To produce continual nanostep motion, conventionally, multiple pairs of piezo-actuators are employed to operate in inchworm principle under complex three- or four-phase timing signal drive. Inspired by the idea of ordered structures with functional units, a much simpler nanostep piezoelectric actuator consisting of (2 × 2) arrayed, cofired multilayer piezoceramic actuation units is developed, which operates in an artificially generated quasi shear mode (AGQSM) that is missing in natural piezoelectric ceramics.
View Article and Find Full Text PDFApproximate rubber/bitumen homogeneous system formed by desulfurization and degradation of crumb tire rubber in bitumen under high temperature is beneficial to enhance the storage stability of rubberized bitumen. However, the main problems during the processing of desulfurized and degraded rubberized bitumen are aging caused by volatilization of light components, and burning or explosion due to the direct utilization of low flash point bitumen. Therefore, waste cooking oil was proposed as a safer medium to desulfurize and degrade crumb rubber prior to production of rubberized bitumen.
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