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Signal delay, execution deviation and reference model mismatch are common faults in autonomous vehicles, resulting in reduced path tracking control performance. To improve the path tracking performance of autonomous vehicles under fault conditions, this paper proposes a hybrid fault-tolerant (HFT) path tracking control approach, in which passive fault-tolerant path tracking control and fault observer-based hybrid active fault-tolerant path tracking control are introduced. The probable usual errors in path tracking are first examined and analyzed, together with the vehicle kinematic model and a typical autonomous driving system. Then, a slide-mode-based passive fault-tolerant path tracking controller is designed and integrated with a fault observer to create a hybrid active fault-tolerant controller. Finally, simulations and experiments are conducted, and the results demonstrate that our proposal is effective. After convergence of the fault observations, the lateral tracking error is less than 0.2m and the root mean square of the tracking error is 44% smaller than the LQR approach. [ABSTRACT FROM AUTHOR]

With the increasing quantity of spent lithium-ion batteries, their recycling problem has become an urgent issue for the economics of such batteries and for the protection of environment. In this study, we proposed a novel green method for the recycling of spent single-crystal LiNixCoyMn1−x−yO2 (NCM) materials. No additional compounds were induced during the direct calcination process to acquire regenerated cathode materials. The surface lithium compounds residues could be fully reutilized combined with an over-discharging pre-treatment, which allowed them to serve as a lithium supplement for the reconstruction of the NCM crystal structure and for the promotion of its electrochemical performance. Via this method, the electrochemical performance of spent cathode materials could be enhanced distinctly and the lithium contents could be reused with high efficiency to alleviate resource shortages. Lithium vacancies were replenished with the decomposition of surficial lithium impurities, and the regenerated NCM exhibited improved cycling stability (129.1 mA h g−1 at 0.5C after 200 cycles) with a well-ordered layered structure compared with spent NCM. Further, the composition and structure evolution of the spent NCM during the regeneration process was also investigated comprehensively combined with in situ XRD characterization. The layered structure of spent NCM remained unchanged, and the regenerated NCM showed bigger lattice parameters, confirming the lithium transmission to reconstruct the lattice structure occurred without phase transformation during the calcination process. This research both provides a new insight into the regeneration mechanism of spent cathode materials and the possibility to recycle spent cathode materials greenly with lower energy consumption than from manufacturing virgin NCM materials. [ABSTRACT FROM AUTHOR]

Temperature dependent synthesis of micro- and meso-porous silica employing the thermo-responsive homopolymer poly( N-isopropylacrylamide) or the random copolymer poly( N-isopropylacrylamide- co-acrylic acid) as structure-directing agent (SDA) and NaSiO as silica source is proposed. The thermo-responsive character of the SDA provides the advantages including (1) temperature dependent synthesis of microporous silica, hierarchically micro-mesoporous silica, and mesoporous silica just by changing the aging temperature below or above the low critical solution temperature of the thermo-responsive SDA, and (2) elimination of the thermo-responsive SDA from silica matrix by water extraction. The synthesis mechanism is discussed, and the effect of the aging temperature and the weight radio of SDA/NaSiO on the synthesis of micro- and meso-porous silica are studied. Microporous silica, hierarchically micro-mesoporous silica and mesoporous silica with the surface area at 3.5−9.0 × 10 m/g and the pore volume at 0.28−1.13 cm/g and the average pore size ranging from 1.1 to 9.0 nm are synthesized. The strategy affords a new and environmentally benign way to fabricate porous silica materials, and is believed to bridge the gap between the synthesis of microporous and mesoporous silica materials. [ABSTRACT FROM AUTHOR]

Au-functionalized hollow shell–corona microspheres with a mesoporous shell are proposed as a microreactor for aerobic alcohol oxidation. These microreactors are constructed by template polymerization followed by hydrolysis of the shell-forming polyvinyltriethoxylsilane segment, and contain a hydrophilic corona to keep the microreactors suspended in the aqueous phase and a mesoporous chelate shell to immobilize Au nanoparticles and to increase the permeability of the microreactors. These microreactors have the ability to encapsulate and concentrate reactants, and have been demonstrated to mediate Au-catalyzed aerobic alcohol oxidation, which takes place efficiently in a quasi-homogeneous aqueous solution and under organic–aqueous biphasic conditions, since the reactants are highly concentrated within the microcavity. Other benefits of the microreactors include easy catalyst reuse, low catalyst leaching and long-term stability. [ABSTRACT FROM AUTHOR]

A porous, thermoresponsive and pH-responsive, and chelating hydrogel of poly(N-isopropylacrylamide)-co-poly[2-methacrylic acid 3-(bis-carboxymethylamino)-2-hydroxypropyl ester] (PNIPAM-co-PMACHE) is proposed as both a reaction medium and the Pd catalyst support for organic synthesis. Organic synthesis within the PNIPAM-co-PMACHE hydrogel has three merits. First, organic reactions such as Suzuki and Heck reactions within the hydrogel can be accelerated due to the enriched Pd catalyst and reactants within the hydrogel by the reversible deswelling/swelling. Second, organic synthesis within the PNIPAM-co-PMACHE hydrogel, which holds about approximately 300 times of water and is similar to the environmentally benign reaction medium of water, can be performed efficiently without surfactant or cosolvent being added. Third, the PNIPAM-co-PMACHE hydrogel itself and the therein-immobilized Pd catalyst can be easily recycled since the hydrogel/Pd composite can reversibly swell/deswell.

A microreactor of hollow polymeric microspheres with Pd nanoparticles immobilized in its wall is designed for hydrogenation of olefins under organic/aqueous biphasic catalysis. The microreactor has an ability to encapsulate and concentrate olefins within the vacancy of the hollow microspheres in the aqueous phase, and therefore hydrogenation within the microreactors runs efficiently with concentrated reactants under organic/aqueous biphasic condition (see scheme).