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PurposeThe performance of the classical car-following system is easily affected by external disturbances. To enhance the performance of the classical car-following model under sudden external disturbances, a novel car-following model is established to smooth traffic flow.Design/methodology/approachThis paper proposed a Proportion Integration Differentiation (PID) control strategy based on classical control theory and developed a novel car-following model. The linear system theory and Laplace transform are used to derive a closed-loop transfer function. Then, the stability condition is obtained by using the Routh stability criterion and the small gain theorem. Finally, the validity and feasibility of the PID control strategy is proved by numerical simulations.FindingsThe analytic results and the numerical simulation results show that both the integration part and the differential part have the positive effect to suppress traffic oscillation efficiently; the collaboration of these two parts has more power to improve the stability of traffic flow. It means that the proposed model integrated with the PID control strategy has the ability of anti-interference and smooth traffic compared with the classical car-following model.Originality/valueThis paper introduces the PID control strategy into the classical car-following system, which enhances the stability of the system and also provides an efficient method for optimizing the traffic flow system.

Layered double hydroxides (LDHs) are a class of two-dimensional (2D) clay compounds that consist of positively charged host layers and exchangeable interlayer anions. The stability of their assemblies in aqueous environment is a challenge due to the extremely high hydrophilicity, which limits their use in membrane-based technologies. Here, we propose a graphene oxide (GO) armour protection strategy to substantially improve the stability of LDH membranes in aqueous solution. The sandwich structured GO/LDH/GO membranes (GLGMs) possess a negative-positive-negative charge heterojunction in the vertical direction that effectively blocks the transport of both cations and anions, i.e., NaCl, but allows the permeation of water molecules. Following this mechanism, the GLGMs are used for desalination in a forward osmosis mode. A high rejection rate of over 95.2% for NaCl and water flux of over 2.1 L m−2 h−1 are achieved with simulated seawater.

Biological hybrid catalysts have emerged as promising approaches to achieve enantioselective reactions in aqueous media. Enantioselective Michael reactions are one of the most important carbon-carbon bond formation reactions in organic synthesis, yet its aqueous-phase catalysis remains challenging. Herein, a single nucleotide-based catalyst (ATP·Cu2+) has been constructed by ATP and Cu2+ ions, which catalyzes Michael reactions in aqueous media with high reactivities and good enantioselectivities up to 83% ee. The enantioselective catalytic performances of ATP·Cu2+ are originated from specific binding between ATP and Cu2+ ions that exhibit both pH-dependent and temperature-dependent behaviors. The ATP·Cu2+ has been demonstrated to be successfully applied to a wide spectrum of enone substrates and carbon nucleophiles.

In this paper, we make an improvement on the conventional visual hull reconstruction method that runs on a single consumer graphics card. The target application is a high-precision diamond inclusion reconstruction system. One major contribution of this paper is an evaluation system of voxels for high-precision reconstruction. In contrast to existing approaches, it allows us to reconstruct the thin structure of the diamond inclusion. Based on this, we obtain a significant improvement in reconstruction precision, especially for thin inclusion.

Porous monolithic catalysts with high specific surface areas, which can not only facilitate heat/mass transfer, but also help to expose active sites, are highly desired in strongly exothermic or endothermic gas-solid phase reactions. In this work, hierarchical spinel monolithic catalysts with a porous woodpile architecture were fabricated via extrusion-based three-dimensional (3D) printing (direct ink writing, DIW in brief) of aluminate-intercalated layered double hydroxide (AI-LDH) followed by low temperature calcination. The intercalation of aluminate in LDH is found crucial to tailor the M2+/Al3+ ratio, integrate LDH nanosheets into monolithic catalyst, and enable the conversion of LDH to spinel at the temperature as low as 500 °C with high specific surface areas (> 350 m2/g). The rapid mass/heat transfer resulted from the versatile 3D network at macroscale and the highly dispersed and fully exposed active sites benefited from the porous structure at microscale endow the 3D-printed Pd loaded spinel MgAl-mixed metal oxide (3D-AI-Pd/MMO) catalyst with excellent catalytic performance in semi-hydrogenation of acetylene, achieving 100% conversion at 60 °C with more than 84% ethylene selectivity. This research was supported by the National Natural Science Foundation of China (Nos. 21935001, 22005022 and 22175012), the program for Changjiang Scholars and Innovation Research Team in the University (No. IRT1205), the starting-up foundation from Beijing University of Chemical Technology (No. BUCTRC202025), the fellowship of China Postdoctoral Science Foundation (No. 2020M670107), the Natural Science Foundation of Beijing, China (No. 2214062), the Fundamental Research Funds for the Central Universities, and the long-term subsidy mechanism from the Ministry of Finance and the Ministry of Education of PRC.

Simultaneous measurement of H

Interspecies coaggregation promotes transcriptional changes in oral bacteria, affecting bacterial pathogenicity. Streptococcus gordonii (S. gordonii) and Fusobacterium nucleatum (F. nucleatum) are common oral inhabitants. The present study investigated the transcriptional profiling of S. gordonii and F. nucleatum subsp. polymorphum in response to the dual-species coaggregation using RNA-seq. Macrophages were infected with both species to explore the influence of bacterial coaggregation on both species’ abilities to survive within macrophages and induce inflammatory responses. Results indicated that, after the 30-min dual-species coaggregation, 116 genes were significantly up-regulated, and 151 genes were significantly down-regulated in S. gordonii; 97 genes were significantly down-regulated, and 114 genes were significantly up-regulated in F. nucleatum subsp. polymorphum. Multiple S. gordonii genes were involved in the biosynthesis and export of cell-wall proteins and carbohydrate metabolism. F. nucleatum subsp. polymorphum genes were mostly associated with translation and protein export. The coaggregation led to decreased expression levels of genes associated with lipopolysaccharide and peptidoglycan biosynthesis. Coaggregation between S. gordonii and F. nucleatum subsp. polymorphum significantly promoted both species’ intracellular survival within macrophages and attenuated the production of pro-inflammatory cytokines IL-6 and IL-1β. Physical interactions between these two species promoted a symbiotic lifestyle and repressed macrophage’s killing and pro-inflammatory responses.

Sustainable water-splitting hydrogen production has long been considered one of the most promising energy conversion technologies, but enormous challenges remain: for instance, water electrolysis suffers from high overpotential and over energy consumption under neutral pH conditions. Here, taking advantage of the memory effect of layered double hydroxide (LDH), we report an energy-efficient neutral water electrolyzer material based on LDH with multiple vacancy defects. Benefiting from the improved electrical conductivity, larger electrochemical surface area (ECSA), and faster charge transfer, the NiFe LDH with O, Ni, and Fe vacancies exhibits a low overpotential of 87 mV at 10 mA/cm2 for hydrogen evolution reaction (HER) in a pH 7 buffer electrolyte. Impressively, the as-fabricated vacancy-containing NiFe LDH (v-NiFe LDH) splits water with a current density of 10 mA/cm2 at ∼1.60 V in a two-electrode device, outperforming most other water-splitting catalysts in neutral media. Such an electrolyzer setup cou...