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It is beneficial to have sensors capable of harvesting photoenergy in the era of Internet of Things (IoT) and 5 G integrated infrastructure. In this paper, we report the piezo-optoelectronic coupling characteristic of n-type 3C‐SiC/n‐type Si heterostructure and demonstrate it with a mechanical strain sensing device capable of harvesting photoenergy. The device is capable of generating a photovoltage as high as 3.4 mV when illuminated by a laser power as small as 10 μW, i.e. four times higher than similar sensors in previous studies. In addition, the strain sensitivity ΔV/V/ε ratios are 9.94 and 13.11 for tensile and compressive strain, respectively, which are five times better than conventional metal strain gauges. These findings contribute to the overall understanding of the piezo-optoelectronic coupling effect of SiC/Si heterojunction paving the way for the development of multifunctional sensors with light harvesting capabilities. [Display omitted] • The piezo-optoelectronic effect in n-SiC/n-Si heterojunction shows a sensitive mechanical strain sensing with light harvests capability. • Superior light harvesting capability, generating a lateral photovoltage four times higher than previous studies, using only 10 μW laser power. • Excellent mechanical strain sensitivity, featuring a ΔV/V/ ε ratio five times better than conventional metal strain gauges. • These findings significantly contribute to the development of multifunctional mechanical sensors with light harvesting capability. [ABSTRACT FROM AUTHOR]

It is highly desirable to discover sensing mechanisms for developing self-powered and ultrasensitive pressure sensing. Here, we report that the piezo-optoelectronic coupling in a n+-3C-SiC/p-Si heterojunction not only enables energy harvesting but also features massive strain sensitivity. To demonstrate the proof of the concept, a pressure sensing device is developed with active and reference electrodes arranged on SiC along strain-sensitive [100] and strain-insensitive [110] orientations, respectively. Under the illumination of 637-nm laser at 2.0 mW, experimental results show the great response of the photogenerated voltage to the change in both static and dynamic pressures. Gauge factor is found to be −670.2 which is much larger than the highest gauge factor of n-type 3C-SiC. The underlying physics behind is the strain modulation on the effective mass and energy level of photogenerated charge carriers. This results in the change in carrier concentration detected by the electrodes along the strain-sensitive and strain-insensitive orientations. These findings could contribute significantly to the development of self-powered mechanical sensors using solid-state electronics. [Display omitted] • Self-powered and ultrasensitive piezo-optoelectronic pressure sensing. • 3C-SiC/Si-based pressure sensing with electrodes along strain-sensitive and strain-insensitive orientations. • Strain modulation on effective mass and energy level of photogenerated charge carriers. • Gauge factor of −670.2 under the illumination of 637-nm laser at 2.0 mW. • Significance to develop self-powered mechanical sensors using solid-state electronics. [ABSTRACT FROM AUTHOR]

• An electric vehicle powertrain equipped with two motors and four-gear ratios. • A two-loop optimization framework combined by the global search method and NSGA-II. • Effect of sizing motors and gear ratios on energy efficiency. • Optimal shift schedules based on the equivalent efficiency of two motors, engaged gears, and driving conditions. • Comparably maximum efficiency achieved while avoiding repeated and unreasonable gear changes. This paper aims to fully exploit the superior advantages in improving energy economy and dynamic performance of an electric vehicle powertrain equipped with two motors and multi-gear ratios. Considering the dependence of gear ratio selection on motor sizing, a two-loop optimization algorithm, combined by the global search method and non-dominated sorting genetic algorithm-II, is proposed to find optimal motor sizes and transmission ratios. An energy management strategy with novel shift schedules based on the equivalent efficiency of two motors, current engaged gears, and driving conditions is then recommended. The energy management strategy also optimizes the torque allocation to two motors to minimize electricity consumption. Subject to the total of motor peak powers being constant, simulation results for a case study of urban bus show that the optimization of both motor sizes and gear ratios considerably enhances the energy efficiency of powertrain system. In comparison with a single-motor powertrain, optimal motor scales of larger than 0.42 and corresponding gear ratios reduce the electricity consumption significantly by 4.82−5.08%. Besides, the introduced energy management strategy with optimal shift schedules is proved to ensure comparably maximum efficiency while effectively preventing unnecessary and repeated gear changes. [ABSTRACT FROM AUTHOR]

• Extended-range electric powertrain equipped with two-motor drive and four-speed AMT. • Novel shift schedule based on the equivalent motor efficiency. • Shift strategies for single-gear change and double-gear change. • Model predictive control-based EMS to allocate motor torques and energy usages. This paper studies the shifting strategy and energy management of a two-motor drive powertrain for extended-range electric buses. To do this, a multibody dynamic model is first established for transient investigation. A novel shift schedule is second proposed by integrating a priority factor for the engaging gear into the equivalent motor efficiency. According to vehicle speed and power, the shift schedule results in two possible cases: single-gear and double-gear change. Optimal shifting strategies are third recommended to eliminate the torque interruption under those possible gear changes. To optimize the torque allocation to two motors and minimize fuel consumption, a model predictive control-based energy management strategy is then developed. Finally, this paper simulates shift quality and energy economy in comparison with a conventional one-motor drive powertrain. The results show that torque interruptions generate large jerks in the one-motor configuration. Conversely, the two-motor configuration achieves great shift quality by eliminating the torque interruptions mostly during single-gear upshift or entirely under double-gear downshift. The two-motor drive powertrain also improves energy economy significantly by 9.1% compared to the conventional configuration. [ABSTRACT FROM AUTHOR]

This paper presents free vibration analyses and nonlinear dynamic responses of new complex edge contour non-rectangular plate structures with a part-through surface crack which the authors name as temporarily double-variable-edge (DVE) plates. The analytical results and numerical simulation are investigated in the Part I and it is expected that the experimental approach will be shown in Part II. The cracked plate made of a functionally graded porous (FGP) matrix structure and reinforced by graphene nano-platelets (GNPs) is covered by two piezoelectric layers and rested on a Winker-Pasternak elastic foundation. The material properties are determined by using the Halpin-Tsai micro-mechanical model, Gaussian Random Field (GRF) proposal, and the rules of mixtures. The governing equations are established based on the classical plate theory (CPT) and Galerkin's method which are convenient in analyzing the behaviors of complex edge contour plates. The obtained results are compared with those obtained from the existing Finite Element Method (FEM) to ensure the reliability and accuracy. In addition, the effects of geometrical shapes, crack parameters, applied voltages of piezoelectric layers, elastic foundations as well as thermal impacts are scrutinized. The obtained outcomes in the paper are promising for applications in the fields of aerospace, civil, and electronic engineering. [Display omitted] • The building of the complicated model of the new structures made of advanced materials with the cracks on the surface. • The effects of complicated factors are considered carefully. • The stable and chaotic states of structures are scrutinized. [ABSTRACT FROM AUTHOR]

• Two parameters of the elastic foundation are expressed in the functions using Selvadurai methodology. • The set of value of (β, α) is found to make the smallest free vibration frequency. • The thermal buckling impacts noticeably on the stiffness of the nanocomposite plate. This paper focuses on effects of non-uniform elastic foundation, that impact on non-linear thermal dynamics of the simply supported plate reinforced by functionally graded (FG) graphene nanoplatelets (GNPs). The Halpin-Tsai micromechanical model and the rule of mixtures are employed to calculate the material properties. By adjusting the volume fraction of matrix/GNPs in the thickness direction, the various distribution patterns of the plates are considered as the uniform distribution (UD) and functionally graded (FG) reinforcements. The governing equations is expressed by using the classical theory, Von Karman-Donnell geometrical nonlinearity assumption, and combining the temperature change. Then the dynamical behaviors of the FG-GNPs reinforced plates are obtained by applying the Airy's stress function and the Galerkin's method. The obtained results are described by the column charts, the 2D and 3D graphs and written by codes of Wolfram-Mathematica. In addition, the present study scrutinizes the effects of the thermal environment, GNPs weight fraction, GNPs distribution patterns, damping coefficient and geometric parameters. More importantly, the influences of the longitudinal variable thickness of Pasternak's subgrade model on the dynamical characteristics are analyzed to optimize structures. Altogether these findings have significant applications in industries engineering and lead to breakthroughs in the microstructures design. [ABSTRACT FROM AUTHOR]

Human cases of H7N9 influenza A virus infection have been increasing since 2013. The first choice of treatment for influenza is neuraminidase (NA) inhibitors (NAIs), but there is a concern that NAI-resistant viruses are selected in the presence of NAIs. In our previous study, an H7N9 virus carrying AA substitution of threonine (T) for isoleucine (I) at residue 222 in NA (NA222T, N2 numbering) and an H7N9 virus carrying AA substitution of lysine (K) for arginine (R) at residue 292 in NA (NA292K, N2 numbering) were found in different macaques that had been infected with A/Anhui/1/2013 (H7N9) and treated with NAIs. In the present study, the variant with NA292K showed not only resistance to NAIs but also lower replication activity in MDCK cells than did the virus with wild-type NA, whereas the variant with NA222T, which was less resistant to NAIs, showed replication activity similar to that of the wild-type virus. Next, we examined the pathogenicity of these H7N9 NAI-resistant viruses in macaques. The variants caused clinical signs similar to those caused by the wild-type virus with similar replication potency. However, the virus with NA292K was replaced within 7 days by that with NA292R (same as the wild-type) in nasal samples from macaques infected with the virus with NA292K, i.e. the so-called revertant (wild-type virus) became dominant in the population in the absence of an NAI. These results suggest that the clinical signs observed in macaques infected with the NA292K virus are caused by the NA292K virus and the NA292R virus and that the virus with NA292K may not replicate continuously in the upper respiratory tract of patients without treatment as effectively as the wild-type virus. • Two NAI-resistant H7N9 influenza viruses were recovered from specimens previously collected from NAI treated macaques. • NAI highly-resistant virus replicated less effectively in vitro than did the wild-type virus. • NAI highly-resistant virus was replaced by the wild-type virus in the nasal cavity of macaques without treatment. [ABSTRACT FROM AUTHOR]