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Palladium (Pd)-based catalysts are widely used for CO2 hydrogenation reactions due to the capability to activate H2, which enhances the overall CO2 conversion. However, most of the current Pd catalysts reported show high CO2 conversion only at higher temperature, and the exploration of efficient catalyst enabling low temperature conversion (180–300 °C) is of importance. In this study, a series of Pd-B/ZnAl2O4 catalysts were synthesized via in-situ doping, resulting in the Pd crystal transformation induced from crystal to amorphous. The catalytic hydrogenation activity of the amorphous Pd-B catalyst reaches its zenith at a Pd-B mole ratio of 1:2, accompanied by the superior catalysis stability in CO2 hydrogenation. Various characterization techniques, including XRD, CO-DRIFTS, H2-TPR, XPS and TEM, were used to investigate the properties of the Pd-B/ZnAl2O4 catalyst. The results showed that the Pd-B/ZnAl2O4 catalyst exhibited higher dispersion and better CO2 conversion efficiency compared to unmodified Pd catalyst. Additionally, the methanol space–time yields are nearly doubled when the B decoration is employed. At 280 °C, CO2 conversion was improved and methanol selectivity remained at ~ 65%. This study provides valuable insights into the design and optimization of Pd-B based catalysts for CO2 hydrogenation at low temperatures. [ABSTRACT FROM AUTHOR]

Maximin distance designs have attracted increasing attention in computer experiments owing to their appealing space‐filling properties. The quality of these designs is typically evaluated by comparing their separation distance with the associated upper bound. Nevertheless, deriving tight upper bounds for the separation distance of designs remains a challenging problem that has been infrequently addressed in the literature. In this study, we obtain a new upper bound for the separation distance of certain classes of five‐level U‐type designs. We also investigate the characteristics of maximin distance U‐type designs and show the optimality of some existing orthogonal designs. Based on these theoretical results, we develop an efficient algorithm for searching maximin distance U‐type designs. Numerical studies and comparisons are given to show the superior performance of the obtained designs. [ABSTRACT FROM AUTHOR]

The timely injection of gangue slurry into the mining space formed after coal mining can scale up the disposal of gangue and control surface deformation. However, the waterproof effect of gangue slurry in the mining space remains unclear, necessitating urgent investigation into the permeability characteristics of compacted backfill bodies of gangue slurry under the action of overburden. In this study, a multi-field coupled seepage test system for backfill materials was developed based on Forchheimer's nonlinear seepage law, and a laboratory preparation method for compacted backfill body (CBB) of gangue slurry after grouting and backfilling in mining space under pseudo-triaxial conditions was proposed. Additionally, the pressure bleeding characteristics of gangue slurry under the action of overburden were studied, the variation law of permeability of the CBB with the axial pressure, a particle size range, and cement dosage was revealed, and the determination method for the permeability level of the CBB and its optimization method were put forward. The research results indicate that there are obvious staged characteristics in the pressure bleeding changes in gangue slurry. Axial pressure, particle size range, and cement dosage all have a significant impact on the permeability of the CBB. The permeability level of the CBB of gangue slurry is within the range of poor permeability and extremely poor permeability. After backfilling into the mining space, gangue slurry exhibits a significant water-blocking effect. [ABSTRACT FROM AUTHOR]

Orthogonal Latin hypercube designs (LHDs) and maximum projection (MaxPro) LHDs are widely used in computer experiments. They are efficient for estimating the trend part and the Gaussian process part of the universal Kriging (i.e., the Gaussian process) model, respectively, especially when only some of the factors are active. Yet, the orthogonality and the MaxPro criteria often do not agree with each other. In this work, we propose a new class of optimal designs, called orthogonal-MaxPro LHDs, optimizing a well-defined multi-objective criterion combining the correlation and the MaxPro metrics. An efficient parallel algorithm via level permutations and expansions is developed, whose efficiency is guaranteed by theories. Numerical results are presented to show that the construction is fast and the obtained designs are attractive, especially for large computer experiments. [ABSTRACT FROM AUTHOR]

The severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) is continuously producing new variants, necessitating effective therapeutics. Patients are not only confronted by the immediate symptoms of infection but also by the long‐term health issues linked to long COVID‐19. Activation of epidermal growth factor receptor (EGFR) signalling during SARS‐CoV‐2 infection promotes virus propagation, mucus hyperproduction, and pulmonary fibrosis, and suppresses the host's antiviral response. Over the long term, EGFR activation in COVID‐19, particularly in COVID‐19‐induced pulmonary fibrosis, may be linked to the development of lung cancer. In this review, we have summarised the significance of EGFR signalling in the context of SARS‐CoV‐2 infection. We also discussed the targeting of EGFR signalling as a promising strategy for COVID‐19 treatment and highlighted erlotinib as a superior option among EGFR inhibitors. Erlotinib effectively blocks EGFR and AAK1, thereby preventing SARS‐CoV‐2 replication, reducing mucus hyperproduction, TNF‐α expression, and enhancing the host's antiviral response. Nevertheless, to evaluate the antiviral efficacy of erlotinib, relevant clinical trials involving an appropriate patient population should be designed. [ABSTRACT FROM AUTHOR]

We investigate a space‐filling criterion based on L2‐type discrepancies, namely the uniform projection criterion, aiming at improving designs' two‐dimensional projection uniformity. Under a general reproducing kernel, we establish a formula for the uniform projection criterion function, which builds a connection between rows and columns of the design. For the commonly used discrepancies, we further use this formula to represent the two‐dimensional projection uniformity in terms of the Lp‐distances of U‐type designs. These results generalize existing works and reveal new links between the two seemingly unrelated criteria of projection uniformity and the maximin Lp‐distance for U‐type designs. We also apply the obtained results to study several families of space‐filling designs with appealing projection uniformity. Because of good projected space‐filling properties, these designs are well adapted for computer experiments, especially for the case where not all the input factors are active. [ABSTRACT FROM AUTHOR]