Quantum State-to-State Dynamics of the H + LiH → H₂ + Li Reaction

State-to-state quantum dynamics calculations for the H + LiH (<i>v</i> = 0–1, <i>j</i> = 0) → H₂ + Li reactions are performed based on an ab initio ground electronic state potential energy surface (PES). Total and product state-resolved integral and differential cross sections and rate constants are calculated. The present total integral cross sections and rate constants for the H + LiH (<i>v</i> = 0, <i>j</i> = 0) reaction are found to be in agreement with previous literature results. Product state-resolved integral cross sections and rate constants reveal that the H₂ products are preferred to be formed in their rovibrational excited states. The differential cross sections show that the intensity of forward scattering for the H₂ products in their rovibrational excited states is stronger than other states. The mechanisms for the <i>v</i> = 0 and <i>v</i> = 1 reactions are found to be highly consistent with each other. Further, the influence of the stripping mechanism on the H + LiH reaction is studied. It is found that the stripping mechanism could be responsible for the decrease of the reactivity, the product state distribution, and scattering direction of the H₂ products. It is related to the “attractive” feature of the underlying PES

DataSheet_1_Implications for functional diversity conservation of China’s marine fisheries.docx

Functional diversity is critical to ecosystem stability and resilience to disturbances as it supports the delivery of ecosystem services on which human societies rely. However, changes in functional diversity over space and time, as well as the importance of particular marine fish species to functional space are less known. Here, we reported a temporal change in the functional diversity of marine capture fisheries from all coastal provinces in China from 1989 to 2018. We suggested that both functional evenness (FEve) and functional divergence (FDiv) changed substantially over time, especially with considerable geographic variation in FEve in the detected patterns. Even within the same sea, the relative contributions of fishes with various water column positions and trophic levels in different waters have different patterns. Together these results underline the need of implementing specific climate-adaptive functional diversity conservation measures and sustainable fisheries management in different waters.</p

Joint optimization of platoon control and resource scheduling in cooperative vehicle-infrastructure system

Vehicle platooning technology is essential in achieving group consensus, on-road safety, and fuel-saving. Meanwhile, Vehicle-to-Infrastructure (V2I) communication significantly facilitates the development of connected vehicles. However, the coupled effects of the longitudinal vehicle’s mobility, platoon control and V2I communication may result in a low reliable communication network between the platoon vehicle and the roadside unit, there is a tradeoff between the platoon control and communication reliability. In this paper, we investigate a biobjective joint optimization problem where the first objective is to maximize the success probability of data transmission (communication reliability) and the second objective function is to minimize the traffic oscillation flow. The vehicle’s mobility state of the platoon vehicle affects the channel capacity and transmission performance. In this context, we deeply explore the relationship between control signals and resource scheduling and theoretically deduce a closed-form expression of the optimal communication reliability objective. Through this closed expression, we transform the bi-objective model into a single objective MPC model by using ?-constraint method. We design an efficient algorithm for solving the joint optimization model and prove the convergence. To verify the effectiveness of the proposed method, we finally evaluate the spacing error, speed error, and resource scheduling of platooning vehicles through simulation experiments in two experimental scenarios. The results show that the proposed control-communication co-design can improve the platoon control performance while satisfying the high reliability of V2I communications

Efficient robust control of mixed platoon for improving fuel economy and ride comfort

The emergence of connected and automated vehicle technology has improved the operational efficiency of mixed traffic systems. This paper studies a two-tier trajectory optimization problem for mixed platooning to improve fuel efficiency, ride comfort, and operational safety during vehicle operations. The proposed model follows a two-tier control logic to plan the trajectory of platooning vehicles with three objectives, including minimizing fuel consumption, maximizing ride comfort, and enhancing the anti-disturbance performance of the platoon. The first is the planning tier, which aims to design the optimal trajectory for Connected and Automated Vehicles (CAVs) based on the optimal fuel consumption and comfort and obtain the expected acceleration curve of CAV. The second is the control tier, which aims to ensure the safe operation of platooning vehicles in the presence of uncertain disturbances in real time. Specifically, we propose a robust tube MPC control method, which dynamically adjusts the CAV acceleration according to the reference trajectory obtained by the planning tier to resist the effects of uncertain disturbances, and the tracking behaviour of Human-Driven Vehicles (HDVs) is offline solved by the robust optimal velocity model. Finally, we design simulation experiments to verify the effectiveness of the proposed two-tier optimization framework. The experimental results show the effectiveness and advantages of the two-tier framework in terms of fuel economy, ride comfort, and robustness against different noise disturbances.</p

Efficient robust control of mixed platoon for improving fuel economy and ride comfort

The emergence of connected and automated vehicle technology has improved the operational efficiency of mixed traffic systems. This paper studies a two-tier trajectory optimization problem for mixed platooning to improve fuel efficiency, ride comfort, and operational safety during vehicle operations. The proposed model follows a two-tier control logic to plan the trajectory of platooning vehicles with three objectives, including minimizing fuel consumption, maximizing ride comfort, and enhancing the anti-disturbance performance of the platoon. The first is the planning tier, which aims to design the optimal trajectory for Connected and Automated Vehicles (CAVs) based on the optimal fuel consumption and comfort and obtain the expected acceleration curve of CAV. The second is the control tier, which aims to ensure the safe operation of platooning vehicles in the presence of uncertain disturbances in real time. Specifically, we propose a robust tube MPC control method, which dynamically adjusts the CAV acceleration according to the reference trajectory obtained by the planning tier to resist the effects of uncertain disturbances, and the tracking behaviour of Human-Driven Vehicles (HDVs) is offline solved by the robust optimal velocity model. Finally, we design simulation experiments to verify the effectiveness of the proposed two-tier optimization framework. The experimental results show the effectiveness and advantages of the two-tier framework in terms of fuel economy, ride comfort, and robustness against different noise disturbances.</p

Cascade Reaction of Thiol–Disulfide Exchange Potentiates Rapid Fabrication of Polymer Hydrogels

We report a rapid cross-linking strategy for the fabrication of polymer hydrogels based on a thiol–disulfide cascade reaction. Specifically, thiolated polymers (e.g., poly(ethylene glycol), hyaluronic acid, sodium alginate, poly(acrylic acid), and poly(methylacrylic acid)) can be cross-linked via the trigger of Ellman’s reagent, resulting in the rapid formation of hydrogels over 20-fold faster than that via the oxidation in air. The gelation kinetics of hydrogels can be tuned by varying the polymer concentration and the molar ratio of Ellman’s reagent and free thiols. The obtained hydrogels can be further functionalized with functional moieties (e.g., targeting ligands) for the selective adhesion of cells. This approach is applicable to various natural and synthetic polymers for the assembly of hydrogels with a minimized gelation time, which is promising for various biological applications

Theoretical Determination of the Rate Coefficient for the HO₂+ HO₂ → H₂O₂<i>+</i>O₂ Reaction: Adiabatic Treatment of Anharmonic Torsional Effects

The HO₂ + HO₂ → H₂O₂ + O₂ chemical reaction is studied using statistical rate theory in conjunction with high level ab initio electronic structure calculations. A new theoretical rate coefficient is generated that is appropriate for both high and low temperature regimes. The transition state region for the ground triplet potential energy surface is characterized using the CASPT2/CBS/aug-cc-pVTZ method with 14 active electrons and 10 active orbitals. The reaction is found to proceed through an intermediate complex bound by approximately 9.79 kcal/mol. There is no potential barrier in the entrance channel, although the free energy barrier was determined using a large Monte Carlo sampling of the HO₂ orientations. The inner (tight) transition state lies below the entrance threshold. It is found that this inner transition state exhibits two saddle points corresponding to torsional conformations of the complex. A unified treatment based on vibrational adiabatic theory is presented that permits the reaction to occur on an equal footing for any value of the torsional angle. The quantum tunneling is also reformulated based on this new approach. The rate coefficient obtained is in good agreement with low temperature experimental results but is significantly lower than the results of shock tube experiments for high temperatures

Discovery of Hydrocarbon-Stapled Short α‑Helical Peptides as Promising Middle East Respiratory Syndrome Coronavirus (MERS-CoV) Fusion Inhibitors

The hexameric α-helical coiled-coil formed between the C-terminal and N-terminal heptad repeat (CHR and NHR) regions of class I viral fusion proteins plays an important role in mediating the fusion of the viral and cellular membranes and provides a clear starting point for molecular mimicry that drives viral fusion inhibitor design. Unfortunately, such peptide mimicry of the short α-helical region in the CHR of Middle East respiratory syndrome coronavirus (MERS-CoV) spike protein has been thwarted by the loss of the peptide’s native α-helical conformation when taken out of the parent protein structure. Here, we describe that appropriate all-hydrocarbon stapling of the short helical portion-based peptide to reinforce its bioactive secondary structure remarkably improves antiviral potency. The resultant stapled peptide P21S10 could effectively inhibit infection by MERS-CoV pseudovirus and its spike protein-mediated cell–cell fusion; additionally, P21S10 exhibits improved pharmacokinetic properties than HR2P-M2, suggesting strong potential for development as an anti-MERS-CoV therapeutic