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We demonstrated herein an electrochemical dearomatizative alkylation of Katritzky salts, wherein Katritzky salts were harnessed as both radical acceptors and donors. A wide range of privileged dihydropyridine scaffolds was constructed with good to excellent yields. Cyclic voltammetry (CV) and electron paramagnetic resonance (EPR) results confirmed the key intermediates-dihydropyridine radicals and gram-scale reaction highlighted the practical and sustainable feature of the newly developed protocol. [ABSTRACT FROM AUTHOR]

To address the low accuracy and stability when applying classical control theory in distribution networks with distributed generation, a control method involving flexible multistate switches (FMSs) is proposed in this study. This approach is based on an improved double-loop recursive fuzzy neural network (DRFNN) sliding mode, which is intended to stably achieve multiterminal power interaction and adaptive arc suppression for single-phase ground faults. First, an improved DRFNN sliding mode control (SMC) method is proposed to overcome the chattering and transient overshoot inherent in the classical SMC and reduce the reliance on a precise mathematical model of the control system. To improve the robustness of the system, an adaptive parameter-adjustment strategy for the DRFNN is designed, where its dynamic mapping capabilities are leveraged to improve the transient compensation control. Additionally, a quasi-continuous secondorder sliding mode controller with a calculus-driven sliding mode surface is developed to improve the current monitoring accuracy and enhance the system stability. The stability of the proposed method and the convergence of the network parameters are verified using the Lyapunov theorem. A simulation model of the three-port FMS with its control system is constructed in MATLAB/Simulink. The simulation result confirms the feasibility and effectiveness of the proposed control strategy based on a comparative analysis. [ABSTRACT FROM AUTHOR]

A novel composite material (TD) composed of TS-1 microcrystalline and dendritic mesoporous silica nanospheres (DMSNs) was successfully prepared. The TD composite material had open pore structure and large specific surface area, which was conducive to the mass transfer of reactants and products. The Ti element in TS-1 could be used as an electron assistant, and the spillover d-electrons were conducive to the improvement of the sulfidation and dispersion of MoS2, thereby forming more type II MoS2 active phases. The incorporation of Ti could bring more Brønsted (B) and Lewis (L) acid, which was conducive to the hydrogenation pathway (HYD) selectivity (41.2%) of dibenzothiophene (DBT) hydrodesulfurization (HDS) and isomerization (ISO) route selectivity (21.9%) of 4,6-dimethyldibenzothiophene (4,6-DMDBT) HDS, thus improve the HDS activity of DBT and 4,6-DMDBT. NiMo/TD-70 (Aging temperature = 70 °C) had the best HDS activities of DBT (99.0%) and 4,6-DMDBT (93.7%) due to its large open pore structure, good acidity, suitable metal-support interaction (MSI) and perfect dispersion of the metallic active sites. [ABSTRACT FROM AUTHOR]

Zhou (2023) introduced the concept of path-factor critical avoidable graph and determined several parameter bounds for (P>2, η) or (P>3, η)-factor critical avoidable graphs. Certain instances are listed in Zhou (2023) to show that these toughness or isolated toughness bounds are sharp. However, the derivation processes are flawed. In this remark, we directly modify the derivation processes and obtain the revised bounds. The counterexamples are updated to satisfy K(G) = η + 2. Finally, richness bounds on binding number for a graph to be path-factor critical avoidable are determined. [ABSTRACT FROM AUTHOR]

The traditional multi-process to enhance tight oil recovery based on fracturing and huff-n-puff has obvious deficiencies, such as low recovery efficiency, rapid production decline, high cost, and complexity, etc. Therefore, a new technology, the so-called fracturing-oil expulsion integration, which does not need flowback after fracturing while making full use of the fracturing energy and gel breaking fluids, are needed to enable efficient exploitation of tight oil. A novel triple-responsive smart fluid based on "pseudo-Gemini" zwitterionic viscoelastic surfactant (VES) consisting of N-erucylamidopropyl-N,Ndimethyl-3-ammonio-2-hydroxy-1-propane-sulfonate (EHSB), N,N,N0,N0-tetramethyl-1,3-propanediamine (TMEDA) and sodium p-toluenesulfonate (NaPts), is developed. Then, the rheology of smart fluid is systematically studied at varying conditions (CO2, temperature and pressure). Moreover, the mechanism of triple-response is discussed in detail. Finally, a series of fracturing and spontaneous imbibition performances are systematically investigated. The smart fluid shows excellent CO2-, thermal-, and pressure-triple responsive behavior. It can meet the technical requirement of tight oil fracturing construction at 140 °C in the presence of 3.5 MPa CO2. The gel breaking fluid shows excellent spontaneous imbibition oil expulsion (~40%), salt resistance (1.2 x 104 mg/L Naþ), temperature resistance (140 °C) and aging stability (30 days). [ABSTRACT FROM AUTHOR]

Lagerstroemia L. (Lythraceae) is a widely distributed genus of trees and shrubs native to tropical and subtropical environments from Southeast Asia to Australia, with numerous species highly valued as ornamentals. Although the plastomes of many species in this genus have been sequenced, the rates of functional gene evolution and their effect on phylogenetic analyses have not been thoroughly examined. We compared three plastome sequence matrices to elucidate how differences in these datasets affected phylogenetic analyses. Robust phylogenetic relationships for Lagerstroemia species were reconstructed based on different plastome sequence partitions and multiple phylogenetic methods. Identification of single-nucleotide variants within different genes also provides basic data on the patterns of functional gene evolution in Lagerstroemia and may provide insights into how those mutations affect protein structure and potentially drive divergence via cytonuclear incompatibility. These results as well as analyses of non-synonymous and synonymous mutations, indicate that heterotachic modes of evolution are present in functional plastome genes and should be accounted for in the analyses of molecular evolution. In addition, divergence events within the Lagerstroemia were dated for the first time. Several of the divergence estimates corresponded to well-known Earth history events, such as the reduction in global temperatures at the Eocene/Oligocene boundary. Our analyses conducted in Lagerstroemia here dissects the various patterns in the divergence of Lagerstroemia and may provide a useful guide to help plant breeders, as well as the necessity of using plastomic data and as possible as to combine evidence from morphological characteristics to investigate the complicated interspecies relationship and the evolutionary dynamics of species. [ABSTRACT FROM AUTHOR]

When a high impedance fault (HIF) occurs in a distribution network, the detection efficiency of traditional protection devices is strongly limited by the weak fault information. In this study, a method based on S-transform (ST) and average singular entropy (ASE) is proposed to identify HIFs. First, a wavelet packet transform (WPT) was applied to extract the feature frequency band. Thereafter, the ST was investigated in each half cycle. Afterwards, the obtained time-frequency matrix was denoised by singular value decomposition (SVD), followed by the calculation of the ASE index. Finally, an appropriate threshold was selected to detect the HIFs. The advantages of this method are the ability of fine band division, adaptive time-frequency transformation, and quantitative expression of signal complexity. The performance of the proposed method was verified by simulated and field data, and further analysis revealed that it could still achieve good results under different conditions. [ABSTRACT FROM AUTHOR]

Measuring the dust explosion characteristics of aluminum-based activated fuels was a prerequisite for developing effective prevention and control measures. In this paper, ignition sensitivity, flame propagation behaviors and explosion severity of aluminum/polytetrafluoroethylene (Al/PTFE) compositions including 2 PT (2.80 wt.% F), 4 PT (7.18 wt.% F) and 8 PT (11.90 wt.% F) were studied. When the content of F increased from 2.80 wt.% to 11.90 wt.%, the minimum explosive concentration MEC decreased from 380 g/m3 to 140 g/m3, due to the dual effects of increased internal active aluminum and enhanced reactivity. The average flame propagation velocities increased as the percentage of F increased. The maximum explosion pressure Pm of 500 g/m3 aluminum-based activated fuels increased from 247 kPa to 299 kPa. Scanning electron microscopy demonstrated that with the increase of PTFE content, the reaction was more complete. On this basis, the explosion mechanism of aluminum-based activated fuels was revealed. [ABSTRACT FROM AUTHOR]

In recent years, the relationship between network graph parameters and the existence of specific H-factor has attracted the attention of researchers. The latest research has found that for factor deleted graphs and factor critical graphs, the tight bounds of graph parameters are changing as the low bound of connectivity changes. This work studies the existence of {K1,1,K1,2,C1}-factor from high-dimensional space perspective. Several surfaces reveal that the dynamic changing of tight parameter (toughness, isolated toughness, sun toughness, binding number) bounds are defined. The precise expression of these surfaces are presented. [ABSTRACT FROM AUTHOR]