Wide usage of vehicle's onboard navigation system offers vehicles better terms to improve energy efficiency. In this paper, a computationally effective energy management strategy using model ...predictive control (MPC) is proposed to find the energy optimal torque split, gear shift, and velocity control of a parallel hybrid electric vehicle (HEV). We consider the vehicles in urban driving, where the vehicle trajectory is constrained by the infrastructure (road signs) and other vehicles (traffic). Restricted by the discrete gear ratio, nonlinear dynamics of the vehicles, and especially different time scales between velocity trajectory and torque split optimization, finding these control variables in one optimal problem is quite challenging. Thus, this paper uses bi-level methodology to reduce computational time and simplify the hybrid optimal problem by decoupling its components into two subproblems. In the outer loop, the optimal velocity trajectory is obtained by solving a nonlinear time-varying optimal problem using a Krylov subspace method to improve computational efficiency. In the second subproblem, we provide an explicit solution of the optimal torque split ratio and gear shift schedule by combining Pontryagin's minimum principle and numerical methods in the framework of MPC. Simulation results on an AMESim model of an HEV with seven-speed automated manual transmission over multiple driving cycles are presented. The results indicate that both energy efficiency and computational speed are improved.
•The recent advances in the additive manufacturing of maraging steels are reviewed.•Various defects are formed with the use of inappropriate processing parameters.•Different techniques contribute to ...forming different molten pool profiles.•Distinct precipitation behaviors are observed during different techniques.•Mechanical properties of the additive manufactured and wrought parts are compared.
This paper reviews the latest research progress in the additive manufacturing (AM) process of 18% nickel maraging steels, which involves laser-based powder bed fusion (L-PBF), laser-based directed energy deposition (L-DED), and wire arc additive manufacturing (WAAM). The emphasis is on the defects, structure, and mechanical properties of the additive manufactured 18% nickel maraging steels. At first, this article outlines the influences of the processing parameters of AM techniques on the defects formed in the fabricated parts, in terms of the L-PBF and WAAM. The macrostructure and microstructure characteristics of as-built and heat-treated 18% nickel maraging steel are then described in detail. Later, the mechanical properties of as-built and heat-treated 18% nickel maraging steel are assessed, such as their tensile, hardness, impact toughness, and fatigue performances. Finally, future directions for work on the AM of 18% nickel maraging steel are provided.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Reinforcement learning is regarded as a potential method to be applied in automated vehicles, but the stability and efficiency of algorithms are concerns. To improve them, the deterministic promotion ...reinforcement learning method is put forward, which can promote the policy determinately. Correspondingly, the policy evaluation in critic and the exploration in actor are improved, which combines a normalization-based evaluation and a model-free search guide. The aim is finding the right action exploration direction by critic, then the direction is used to update and guide action exploration in actor. The modified method decreases the dependencies of exploring a good action for promotional updating and only makes deterministic promotion in policy. Consequently, the efficiency of the algorithm is improved without loss in stability. More notably, it can relieve the cold-start and circumvent the limitations in learning with constrained physical systems. To verify the proposed method, the longitudinal velocity control problem for automated vehicles is considered, which contains car-following and non-car-following conditions in a unitized form. The learning system is established in Carsim. Furthermore, some different reinforcement learning technologies are used to accelerate learning. Real-vehicle experiments for validation are also given. The results indicate that the proposed method can achieve permissible learning performance in the longitudinal velocity continuous control problem.
N-doped carbon dot (NCD)@COF
BTT-Th
nanosheets with strong dual-emission fluorescence are prepared by encapsulating NCDs into COF
BTT-Th
through amine-aldehyde dehydration condensation between ...benzotrithiophene tricarbaldehyde and terephthalic dihydrazide. The fluorescence of COF
BTT-Th
is enhanced because of fluorescence resonance energy transfer and the decrease of interlaminar accumulation and intramolecular rotation.
NCDs are encapsulated into COF
BTT-Th
to enhance the COF
BTT-Th
fluorescence based on RET and decrease the interlaminar accumulation and intramolecular rotation.
In the clades of animals that diverged from the bony fish, a group of Mas-related G-protein-coupled receptors (MRGPRs) evolved that have an active role in itch and allergic signals
. As an MRGPR, ...MRGPRX2 is known to sense basic secretagogues (agents that promote secretion) and is involved in itch signals and eliciting pseudoallergic reactions
. MRGPRX2 has been targeted by drug development efforts to prevent the side effects induced by certain drugs or to treat allergic diseases. Here we report a set of cryo-electron microscopy structures of the MRGPRX2-G
trimer in complex with polycationic compound 48/80 or with inflammatory peptides. The structures of the MRGPRX2-G
complex exhibited shallow, solvent-exposed ligand-binding pockets. We identified key common structural features of MRGPRX2 and describe a consensus motif for peptidic allergens. Beneath the ligand-binding pocket, the unusual kink formation at transmembrane domain 6 (TM6) and the replacement of the general toggle switch from Trp
to Gly
(superscript annotations as per Ballesteros-Weinstein nomenclature) suggest a distinct activation process. We characterized the interfaces of MRGPRX2 and the G
trimer, and mapped the residues associated with key single-nucleotide polymorphisms on both the ligand and G-protein interfaces of MRGPRX2. Collectively, our results provide a structural basis for the sensing of cationic allergens by MRGPRX2, potentially facilitating the rational design of therapies to prevent unwanted pseudoallergic reactions.
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The development of high-definition (HD) maps has enabled predictive cruise control (PCC) systems to access additional road and traffic information. This study provides a novel control scheme of PCC, ...which utilizes HD map information. To minimize fuel consumption, the problem of the PCC is formulated as a nonlinear model predictive control, and the derivation and implementation of the fast solver are discussed. Then, a novel shift-map is proposed to define the different working regions to allow the application of the proposed PCC system. The use of the real-time HD map is discussed, and the proposed control scheme is evaluated through simulation and experimental tests. The total fuel-savings rates obtained with the PCC system and factory-installed ACC system over a 370 km route were compared. An average fuel-savings rate of as high as 8.73% can be obtained by the proposed PCC system.
The G-protein-coupled bile acid receptor (GPBAR) conveys the cross-membrane signalling of a vast variety of bile acids and is a signalling hub in the liver-bile acid-microbiota-metabolism axis
. Here ...we report the cryo-electron microscopy structures of GPBAR-G
complexes stabilized by either the high-affinity P395
or the semisynthesized bile acid derivative INT-777
at 3 Å resolution. These structures revealed a large oval pocket that contains several polar groups positioned to accommodate the amphipathic cholic core of bile acids, a fingerprint of key residues to recognize diverse bile acids in the orthosteric site, a putative second bile acid-binding site with allosteric properties and structural features that contribute to bias properties. Moreover, GPBAR undertakes an atypical mode of activation and G protein coupling that features a different set of key residues connecting the ligand-binding pocket to the G
-coupling site, and a specific interaction motif that is localized in intracellular loop 3. Overall, our study not only reveals unique structural features of GPBAR that are involved in bile acid recognition and allosteric effects, but also suggests the presence of distinct connecting mechanisms between the ligand-binding pocket and the G-protein-binding site in the G-protein-coupled receptor superfamily.
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A design method for the gearshift strategy in powertrain systems is proposed to explore the energy saving potential of an electric vehicle (EV) equipped with a multispeed automated manual ...transmission (AMT). The optimal gearshift schedule is obtained by solving a nonlinear time-varying optimal problem in the framework of model predictive control, wherein, the vehicle driveability, represented by the driver's power demand satisfaction, and battery efficiency are considered. The solution approach is developed basing on the combination of Pontryagin's minimum principle and numerical methods, in addition to the real-time applications. Simulation results for a passenger EV with four-speed AMT on different drive cycles show that compared with the case of a standard gearshift strategy, an additional fuel saving can reach 3-5% and even more when considering road characteristic such as road slope. Furthermore, hardware in the Loop simulation for experimental validation is also given in this paper. Results indicate that both energy efficiency and computational speed are improved.
Energy consumption of a vehicle is greatly influenced by its driving behavior, which is reflected by gear shift strategy in powertrain systems. Because of the discrete gear ratio and nonlinear ...dynamics of vehicles, devising an optimal gear shift strategy is quite challenging. This paper presents an online shift schedule optimization strategy for improving energy efficiency of an electric vehicle (EV) with 2-speed automated manual transmission (AMT). The optimal gear shift strategy is obtained by solving a nonlinear time-varying optimal problem, wherein, the equivalent energy consumption, including motor power and travelling distance is chosen as the objective function. By exploiting the particular structure of the problem and combining Pontryagin's minimum principle and numerical methods, a compuationally efficient solution approach is proposed, in the frame of moving horizon control. Simulation results on an AMESim model of an EV with 2-speed AMT over multiple driving cycles using different controllers are presented, and Hardware in the Loop simulation for experimental validation is also given in this paper. The results indicate that both energy efficiency and computational speed are improved.
Lanthanide amides are some of the most important reagents and catalysts in lanthanide organometallic chemistry because of their high stability. Nevertheless, the readily available homoleptic ...LnN(SiMe3)2 n (n = 2, 3) complexes lack feasible strategies to modulate their reactivity and selectivity. In this paper, monodentate N-heterocyclic carbenes (NHCs) were applied to synthesize the divalent lanthanide bis(amido) adducts 3,4Sm and 2–4,7,8Eu. σ-bond metathesis reactions of (IiPr)2YbN(SiMe3)22 (2Yb; IiPr = 1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene) with alkyne, aniline, and phenol yielded alkynyl-bridged (IiPr)YbN(SiMe3)2(μ-CCtBu)2 (9), monomeric (IiPr)2YbN(SiMe3)2(NHAr1) (10; Ar1 = 2,6-iPr2C6H3), and (IiPr)2Yb(OAr2)2 (11; Ar2 = 2,6-tBu2-4-MeC6H2), respectively. All of the NHC adducts of lanthanide(II) complexes were structurally characterized by X-ray diffraction analysis. Moreover, 4Sm has high activity in the ROP of rac-LA without an alcohol initiator. Preliminary mechanism studies reveal that the ROP by 4Sm was initiated through a coordination–insertion mechanism, which involves electrophilic activation of the monomer by the metal center and nucleophilic attack of the amido group on the activated monomer. These studies demonstrate that the diverse NHCs could be potential ligands to not only suppress the ligand redistribution of heteroleptic Ln(II) complexes but also modulate the reactivity of lanthanide amide catalysts.
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