Precise Position Adjustment of Automotive Electro-Hydraulic Coupling System with Parameter Perturbations

Based on the guaranteed cost theory, this paper proposes a robust controller for the automotive electro-hydraulic coupling system. However, parameter perturbation caused by the model linearization is a critical challenge for the nonlinear electro-hydraulic coupling system. Generally, the electrical brake booster system (E-Booster) can be separated into three parts, a permanent magnet synchronous motor (PMSM), a hydraulic model of the master cylinder, and the transmission mechanism. In this paper, the robust guaranteed cost controller (RGCC) could adjust accurately the pushrod position of the E-Booster and has strong robustness against internal uncertainties, and the linear extended state observer (LESO) was utilized to optimize E-Booster's dynamic performance. Thus, the tracking differentiator (TD) and LESO are used to improve the dynamic precision and reduce the hysteresis effect. The overshoot is suppressed by TD, and the disturbance caused by nonlinear uncertainty is restrained by LESO. Experiment results show that RGCC sacrifices 6% phase lag in the low-frequency domain for a 10% and 40% reduction in first and second-order respectively compared with the proportion integration differentiation (PID). Results demonstrate that RGCC has higher precision and stronger robustness in dynamic behaviour.

Significant Near Field Enhancement Over Large Volumes Around Metal Nanorods via Strong Coupling of Surface Lattice Resonances and Fabry-Pérot Resonance

Metal nanoparticles supporting plasmons are widely used to enhance electromagnetic fields, resulting in strong light-matter interactions at the nanoscale in a diverse range of applications. Recently, it has been shown that when metal nanorods are periodically arranged with proper lattice periods, surface lattice resonances (SLRs) can be excited and near fields can be greatly enhanced over extended volumes. In this work, we report significant near field enhancement over even larger volumes by placing the metal nanorod array within a Fabry-Pérot (F-P) microcavity. Results show that taking advantage of strong coupling between the SLR and the photonic F-P resonances, the electric field intensity of the bonding split mode can be enhanced by up to 1935 times, which is about three times of the enhancement of the SLR, and the greatly enhanced field can extend over most of the F-P microcavity. We further show that the F-P resonances of both odd and even orders can strongly couple to the SLR by varying the nanorods position from the middle of the microcavity. We expect that the proposed plasmonic-photonic coupling system will find promising applications in nanolasers, nonlinear optics and sensing.

Optical one-dimensional waveguides in oxyfluoride glass fabricated by Helium Ion implantation

In this work, a one-dimensional waveguide is formed by virtue of the helium ion implantation in the oxyfluoride glass (OFG). The energy and the fluence of the ion implantation are 0.4 MeV and [Formula: see text] [Formula: see text], respectively. The m-line curve with the effective refractive indices of the modes was recorded by using the prism coupling system. The energy loss distribution and the refractive index profile were calculated by the stopping and range of ions into matter (SRIM)-2013 and the RCM, respectively. The light modal profile was measured by the end-facet coupling system. It suggests that the He[Formula: see text]-ion implanted OFG waveguides have the potential to act as integrated photonic devices.

Integrative Analysis of the Transcriptome and Metabolome Reveals the Mechanism of Saline–Alkali Stress Tolerance in Astragalus membranaceus (Fisch) Bge. var. mongholicus (Bge.) Hsiao

Saline–alkali stress is a major abiotic stress affecting the quality and yield of crops. Astragalus membranaceus (Fisch) Bge. var. mongholicus (Bge.) Hsiao (A. mongholicus) is a well-known medicine food homology species with various pharmacological effects and health benefits that can grow well in saline–alkali soil. However, the molecular mechanisms underlying the adaptation of A. mongholicus plants to saline–alkali stress have not yet been clarified. Here, A. mongholicus plants were exposed to long-term saline–alkali stress (200 mmol·L -1 mixed saline–alkali solution), which limited the growth of A. mongholicus. The roots of A. mongholicus could resist long-term saline–alkali stress by increasing the activity of antioxidant enzymes and the content of osmolytes. Transcriptome analysis (via the Illumina platform) and metabolome analysis (via the Nexera UPLC Series QE Liquid Mass Coupling System) revealed that saline–alkali stress altered the activity of various metabolic pathways (e.g., amino acid metabolism, carbohydrate metabolism, lipid metabolism, and biosynthesis of other secondary metabolites). A total of 3,690 differentially expressed genes (DEGs) and 997 differentially accumulated metabolites (DAMs) were identified in A. mongholicus roots under saline–alkali stress, and flavonoid-related DEGs and DAMs were significantly up-regulated. Pearson correlation analysis revealed significant correlations between DEGs and DAMs related to flavonoid metabolism. MYB transcription factors might also contribute to the regulation of flavonoid biosynthesis. Overall, the results indicate that A. mongholicus plants adapt to saline–alkali stress by up-regulating the biosynthesis of flavonoids, which enhances the medicinal value of A. mongholicus.

Fabrication and properties of the He+-implanted K9 glass waveguide

This work reports on the fabrication and characterization of a K9 glass planar waveguide structure. The helium ion implantation was employed to form the waveguide on the K9 glass. The choices of the energy of 0.4 MeV and the dose of [Formula: see text] ions/cm2 were conducted by the SRIM 2013. The [Formula: see text]-line spectroscopy and the modal profile of the He[Formula: see text]-irradiated K9 glass waveguide were performed by the prism-coupling system and the end-face coupling technique at 0.6328 [Formula: see text]m, which suggests the capability of light propagation. The He[Formula: see text]-implanted K9 glass waveguides can serve as potential candidates for advanced integrated optoelectronic devices.

Multiscenario-Based Train Headway Analysis under Virtual Coupling System

Chinese high-speed railway has implemented large-scale network operation with an urgent need for capacity improvement. The concept of virtual coupling seems to be a promising solution that provides a new operational scenario for high-speed railway, where trains are formed into a cooperative convoy and run synchronously with small train headways. The train-following principles under the virtual coupling signalling are quite different from those under conventional train control systems. Therefore, train headway analysis for different operational scenarios should be carried out to ensure railway safety and evaluate capacity benefits brought by virtual coupling. This paper proposes a potential virtual coupling architecture with reference to ETCS/ERTMS specifications. We compare blocking time models under different train control systems, and eight typical train-following scenarios are investigated for virtual coupling, including train arrival and departure cases. A detailed multiscenario-based train headway analysis is provided based on the microscopic infrastructure of the station and technological characteristics of virtual coupling. All computational outcomes are based on the train dynamic motion model. A comparative analysis of train headways under virtual coupling and CTCS-3 is provided in the case study. Results show that train headways can be substantially reduced under virtual coupling and are related to the station infrastructure layout.

On the stability of recovering two sources and initial status in a stochastic hyperbolic-parabolic system

Consider an inverse problem of determining two stochastic source functions and the initial status simultaneously in a stochastic thermoelastic system, which is constituted of two stochastic equations of different types, namely a parabolic equation and a hyperbolic equation. To establish the conditional stability for such a coupling system in terms of some suitable norms revealing the stochastic property of the governed system, we first establish two Carleman estimates with regular weight function and two large parameters for stochastic parabolic equation and stochastic hyperbolic equation, respectively. By means of these two Carleman estimates, we finally prove the conditional stability for our inverse problem, provided the source in the elastic equation be known near the boundary and the solution be in a prior bound set. Due to the lack of information about the time derivative of wave field at final moment, the stability index with respect to the wave field at final time is found to be halved, which reveals the special characteristic of our inverse problem for the coupling system.