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Polyhedral boranes have potential applications in medicine and material science due to their unique structure and stability. However, tedious and low-yield synthetic methods limited their application. Herein, we have developed a facile large-scale synthetic method for M2[B12H12] (M = Na, K) by the reaction of MBH4with N,N-dipropylaniline borane in diglyme at 120 or 140 °C in up to 88% yield. The mechanistic studies indicated that intermediates, such as [B3H8]−and [B9H14]−, were formed in the formation process of [B12H12]2–anion, similar to previously reported. The formation of B2H6from the N,N-dipropylaniline borane adducts is most important. The developed method avoided using toxic materials, with high yield, easily scaled up, raw materials are readily available. Additionally, the starting material, N,N-dipropylaniline, could be repeatedly used at least three times with similar yields, which is an economical way to facilitate industrial synthesis. It is believed that this method will support further application of Na2[B12H12] and K2[B12H12] as solid electrolytes for an all-solid-state batteries.

In the context of automotive lightweighting strategy, steel/aluminum hybrid structures are widely used in the automotive industry. To address the reliability of steel/aluminum dissimilar metal joints, this study conducted steel/aluminum dissimilar metal laser welding tests by Taguchi’s design of experiments method and obtained relevant data. Based on the test results, a Kriging model with laser power, welding speed, and defocusing amount as inputs, and base material deformation and welded joint tensile strength as outputs was established. In this paper, with the amount of deformation of base material and tensile strength of welded joints after welding as the optimization objectives, the optimization analysis is carried out by combining the Kriging model and the multi-objective bottled sea-sheath swarm optimization algorithm (MSSA). The results show that under the conditions of laser power of 450 W, welding speed of 11.88 mm/s, and defocusing amount of 5.3 mm, the optimization objective reaches the optimal level, the base material warpage deformation is reduced by 22.33% compared with the pre-optimization, and the tensile strength of the welded joints is improved by 18.01%.

Molecules with high point-group symmetry are interesting prototype species in the textbook. As transition metal-centered boron clusters tend to have highly symmetric structures to fulfill multicenter bonding and high stability, new boron clusters with rare point-group symmetry may be viable. Through in-depth scrutiny over the structures of experimentally already observed transition metal-centered boron-wheel complexes, geometric and electronic design principles are summarized, based on which we studied M©B11k–(M= Y, La; Zr, Hf; k= 1, 2) clusters and found that a Y©B112–boron-wheel complex has an unprecedented D11hpoint-group symmetry. The remarkable stability of the planar Y©B112–complex is illustrated via extensive global-minimum structural search as well as comprehensive chemical bonding analyses. Similar to other boron-wheel complexes, the Y©B112–complex is shown to possess σ and π double aromaticity, indeed following the electronic design principle previously summarized. This new compound is expected to be experimentally identified, which will extend the currently known largest possible planar molecular symmetry and enrich the metal-centered boron-wheel class.

Accurate modeling for highly non-linear coupling of a damaged ship with liquid sloshing in waves is still of considerable interest within the computational fluid dynamics (CFD) and AI framework. This paper describes a data-driven Stacking algorithm for fast prediction of roll motion response amplitudes in beam waves by constructing a hydrodynamics model of a damaged ship based on the dynamic overlapping grid CFD technology. The general idea is to optimize various parameters varying with four types of classical base models like multi-layer perception, support vector regression, random forest, and hist gradient boosting regression. This offers several attractive properties in terms of accuracy and efficiency by choosing the standard DTMB 5415 model with double damaged compartments for validation. It is clearly demonstrated that the predicted response amplitude operator (RAO) in the regular beam waves agrees well with the experimental data available, which verifies the accuracy of the established damaged ship hydrodynamics model. Given high-quality CFD samples, therefore, implementation of the designed Stacking algorithm with its optimal combination can predict the damaged ship roll motion amplitudes effectively and accurately (e.g., the coefficient of determination 0.9926, the average absolute error 0.0955 and CPU 3s), by comparison of four types of typical base models and their various forms. Importantly, the established Stacking algorithm provides one potential that can break through problems involving the time-consuming and low efficiency for large-scale lengthy CFD simulations.

The combination of photodynamic therapy (PDT) and chemodynamic therapy (CDT) in tumor treatment has attracted considerable attention. However, tumor hypoxia and glutathione (GSH) overproduction in the tumor tissue restricted the progress of their applications. Herein, a Mn-porphyrinic metal–organic framework (Mn-TCPP) was constructed by the one-pot method and further used for immobilizing glucose oxidase (GOx) to obtain GOx@Mn-TCPP. GOx would rapidly exhaust endogenous glucose into hydrogen peroxide (H2O2) and gluconic acid, thus shutting off the energy supply of tumor cells for starvation treatment. Mn-TCPP catalyzed H2O2to produce oxygen, regulating the hypoxic tumor microenvironment and in turn improving 1O2generation under laser irradiation. Interestingly, Mn-TCPP can reduce reactive oxygen species consumption owing to the redox reaction between Mn3+and GSH, thus greatly enhancing PDT. Furthermore, benefiting from GOx-mediated starvation therapy, Mn2+produced by Mn3+reduction can react with sufficient intracellular H2O2to generate ·OH with high cytotoxicity through a Fenton-like reaction. After treatment by GOx@Mn-TCPP under laser irradiation in vitro, the cell viability of 4T1 and A549 tumor cells reached to 20%, reflecting GOx@Mn-TCPP could give full play to the advantages of PDT/CDT/starvation therapy. The results in vivo demonstrated that GOx@Mn-TCPP mediated synergistic cascade therapy could significantly inhibit tumor growth and improve the therapeutic effect.

Titanium and its alloys are protected by a compact and stable passive film, which confers resistance to corrosion by the primary halogen chloride (Cl–) while being less effective against fluoride (F–). Although researchers have recognized different macroscopic corrosion effects of these halide ions on titanium, the underlying mechanisms remain largely unexplored. In this work, the bonding of Cl–/F–with stable passive films was studied in neutral and acidic (pH = 2.3) conditions. The synergistic effect between the interfacial hydrogen bond (HB) structure and halogens on titanium corrosion was first revealed using first-principles calculation and Raman spectroscopy. F–forms more stable halogen–Ti bonds than Cl–, resulting in titanium degradation. The proton combined with F–exhibits a specific synergistic effect, causing corrosion of the passive film. The water hydrogen bond transformation index (HBTI) at the titanium/aqueous interface was 1.88 in an acidic solution containing F–, significantly higher than that in neutral/acid solutions containing Cl–(1.80/1.81) and a neutral solution containing F–(1.81). This work clarifies the structure–activity relationship between HBTI and the destruction of titanium passive films. We propose that the microstructure of the interfacial HB is an undeniable factor in the corrosion of titanium.

An asymmetric synthesis of chiral 2,5-diketopiperazines by the Ugi-4CR/cyclization is exhibited. The employment of catalytic anionic chiral Co(III) complexes delivered α-propiolyl aminoamides in high yields with excellent enantioselectivities (31 examples, up to 95% ee). The following treatment of Ugi-adducts with PPh3leads to chiral 2,5-DKPs without significant loss of enantioselectivities (26 examples, up to 91% ee).

Excessive fructose consumption increases hepatic de novo lipogenesis, resulting in cellular stress, inflammation and liver injury. Nogo-B is a resident protein of the endoplasmic reticulum that regulates its structure and function. Hepatic Nogo-B is a key protein in glycolipid metabolism, and inhibition of Nogo-B has protective effects against metabolic syndrome, thus small molecules that inhibit Nogo-B have therapeutic benefits for glycolipid metabolism disorders. In this study we tested 14 flavones/isoflavones in hepatocytes using dual luciferase reporter system based on the Nogo-B transcriptional response system, and found that 6-methyl flavone (6-MF) exerted the strongest inhibition on Nogo-B expression in hepatocytes with an IC50value of 15.85 μM. Administration of 6-MF (50 mg· kg−1·d−1, i.g. for 3 weeks) significantly improved insulin resistance along with ameliorated liver injury and hypertriglyceridemia in high fructose diet-fed mice. In HepG2 cells cultured in a media containing an FA-fructose mixture, 6-MF (15 μM) significantly inhibited lipid synthesis, oxidative stress and inflammatory responses. Furthermore, we revealed that 6-MF inhibited Nogo-B/ChREBP-mediated fatty acid synthesis and reduced lipid accumulation in hepatocytes by restoring cellular autophagy and promoting fatty acid oxidation via the AMPKα-mTOR pathway. Thus, 6-MF may serve as a potential Nogo-B inhibitor to treat metabolic syndrome caused by glycolipid metabolism dysregulation.

The utilization of carboranes in supramolecular chemistry has attracted considerable attention. The unique spatial configuration and weak interaction forces of carboranes can help to explore the properties of supramolecular complexes, particularly via host–guest chemistry. Additionally, certain difficulties encountered in carborane development─such as controlled B–H bond activation─can be overcome by judiciously selecting metal centers and their adjacent ligands. However, few studies are being conducted in this nascent research area. With advances in this field, novel carborane-based supramolecular complexes will likely be prepared, structurally characterized, and intrinsically investigated. To expedite these efforts, we present major findings from recent studies, including π–π interactions, host–guest associations, and steric effects, which have been leveraged to implement a regioselective process for activating B(2,9)–, B(2,8)–, and B(2,7)–H bonds of para-carboranes and B(4,7)–H bonds of ortho-carboranes. Future studies should clarify the unique weak interactions of carboranes and their potential for enhancing the utility of supramolecular complexes. Although carboranes exhibit several unique weak interactions (such as dihydrogen-bond [Bδ+–Hδ−···Hδ+–Cδ−], Bδ+–Hδ−···M+, and Bδ+–Hδ−···π interactions), the manner in which they can be utilized remains unclear. Supramolecular complexes, particularly those based on host–guest chemistry, can be utilized as a platform for demonstrating potential applications of these weak interactions. Owing to the importance of alkane separation, applications related to the recognition and separation of alkane isomers via dihydrogen-bond interactions are primarily summarized. Advances in the research of unique weak interactions in carboranes will certainly lead to more possibilities for supramolecular chemistry.

Cavitation within the tip vortex (TV) flow remains a challenging issue in the design of high-speed and low-noise hydraulic machinery. In this paper, the TV cavitating flow around an elliptical hydrofoil is calculated by using large eddy simulation (LES) combined with a modified Schnerr-Sauer (S-S) cavitation model. The original S-S cavitation model is modified by taking into account the typical effect of vortex flow. The partial pressure term which can describe the vortex quantitatively and qualitatively is confirmed as ρmωx2rc2, and is considered into the R-P equation of the modified S-S cavitation model. Comparison between the numerical and experimental results shows good agreement in the form and evolution of cavities, including attached cavities (AC) and tip vortex cavities (TVC). The vorticity transport equation is utilized to investigate the dynamic mechanisms of the vortex development around the TVC. Further analyses indicate that cavitation in the TV flow influences the pressure in the core of the cavity and the local flow patterns. Typical vortex structures in the TV cavitating flow include TV, secondary vortex (SV) and wake vortex (WV). The direction and magnitude of the rotation effect can be described by axial vorticity which is drawn on the iso-surface of Q= 1 × 105s−2. The development of the TV cavitating flow can be divided into two stages: Stage I, the development and fusion of TV, SV, stage II, the dissipation of SV. The stretching term dominates the evolution of TV, and the dilatation term is the main reason in the mergence process of SV.

Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is an essential regulatory target of antioxidants, but the lack of Nrf2 active site information has hindered discovery of new Nrf2 agonists from food-derived compounds by large-scale virtual screening. Two deep-learning models were separately trained to screen for Nrf2-agonists and safety. The trained models screened potentially active chemicals from approximately 70,000 dietary compounds within 5 min. Of the 169 potential Nrf2 agonists identified via deep-learning screening, 137 had not been reported before. Six compounds selected from the new Nrf2 agonists significantly increased (p< 0.05) the activity of Nrf2 on carbon tetrachloride (CCl4)-intoxicated HepG2 cells (nicotiflorin (99.44 ± 18.5%), artemetin (97.91 ± 8.22%), daidzin (87.73 ± 3.77%), linonin (74.27 ± 5.73%), sinensetin (72.74 ± 10.41%), and tectoridin (77.78 ± 4.80%)), and their safety were demonstrated by an MTT assay. The safety and Nrf2 agonistic activity of nicotiflorin, artemetin, and daidzin were also reconfirm by a single-dose acute oral toxicity study and CCl4-intoxicated rat assay.

Developing novel assembly methods for supramolecular compounds has long been a research challenge. Herein, we describe how to integrate the B–C coupling reaction and “cage walking” process into coordination self-assembly to construct supramolecular cages. In this strategy, dipyridine linkers containing alkynes react with the metallized carborane backbone through B–C coupling and then “cage walking” resulting in metallacages. However, dipyridine linkers without alkynyl groups can form only metallacycles. We can regulate the size of metallacages based on the length of the alkynyl bipyridine linkers. When tridentate-pyridine linkers participate in this reaction, a new type of ravel is formed. The metallization of carboranes, the B–C coupling reaction, and especially the “cage walking” process of carborane cages play a vital role in this reaction. This work provides a promising principle for the synthesis of metallacages and opens up a novel opportunity in the supramolecular field.

The development of industrial Internet technology enterprises plays an important supporting role in green water and green mountains, as a forestry industry with both economic value and ecological value. at present, it is facing a good opportunity for development. However, industrial Internet technology enterprises are faced with many risks, such as long investment cycle, low comparative income, and their ecological value is easy to be ignored. Based on FCFF model and LINEST function, this paper studies the enterprise value evaluation and ecological development. The main conclusions are as follows: (1) the economic value of industrial Internet technology enterprises is greatly affected by non-financial factors; (2) the excess income of industrial Internet technology enterprises is affected by ecological improvement. (3) under the background of green finance, the comprehensive operation ability of enterprises can be effectively improved through internal control of enterprises, formulation of government laws and supervision of social enterprises. This study has important theoretical and practical significance for China to scientifically and reasonably evaluate the value of industrial Internet technology enterprises.

Manipulating magnetic skyrmions by means of a femtosecond (fs) laser pulse has attracted great interest due to their promising applications in efficient information-storage devices with ultralow energy consumption. However, the mechanism underlying the creation of skyrmions induced by an fs laser is still lacking. As a result, a key challenge is to reveal the pathway for the massive reorientation of magnetization from trivial to nontrivial topological states. Here, we studied a series of ferrimagnetic CoHo alloys and investigated the effect of a single laser pulse on the magnetic states. Thanks to the time-resolved magneto-optical Kerr effect and imaging techniques, we demonstrate that the laser-induced phase transitions from single domains into a topological skyrmion phase are mediated by the transient in-plane magnetization state, in real time and space domains, respectively. Combining experiments and micromagnetic simulations, we propose a two-step process for creating skyrmions through laser pulse irradiation: (i) the electron temperature enhancement induces a spin reorientation transition on a picosecond (ps) timescale due to the suppression of perpendicular magnetic anisotropy (PMA) and (ii) the PMA slowly restores, accompanied by out-of-plane magnetization recovery, leading to the generation of skyrmions with the help of spin fluctuations. This work provides a route to control skyrmion patterns using an fs laser, thereby establishing the foundation for further exploration of topological magnetism at ultrafast timescales.

Four kinds of typical plasma electrolytic oxidation (PEO) coatings were prepared on TC4 alloy to investigate the influence of electrolyte composition on the corrosion behavior and tribological performance of the PEO coatings. The results show that both the corrosion behavior and tribological performance of the PEO coatings are highly dependent on the electrolyte composition. The PEO coating fabricated from the electrolyte containing NaH2PO2exhibits the best corrosion resistance owing to its denser inner layer. The PEO coating prepared from the electrolyte containing NaAlO2reveals the best tribological performance due to the generation of Al2O3. To prepare a PEO coating with satisfying corrosion resistance and wear resistance, a composite PEO coating was fabricated from the electrolyte containing NaH2PO2and NaAlO2.

Polyhedral boranes are a class of well-known boron molecular clusters with unique physical and chemical properties, and great efforts have been made in the past decades to find more effective synthetic methods. However, the established synthetic methods suffer from low efficiency and low selectivity because the mechanism of the B–H bond condensation reaction, critical for the synthesis of the polyhedral boranes, is not well understood. Here we report highly selective and efficient synthetic methods of the salts of the tetradecahydridoundecaborate (1–) (B11H14−) and dodecahydrido-dodecaborates (2–) (B12H122−) anions by employing commercially available and inexpensive starting materials. Both theoretical and experimental investigations are carried out to elucidate the reaction mechanisms. We have found that the nature of the B–H bond condensation is the dihydrogen bonding interaction in which the positively charged hydrogens (bridged hydrogens) play a crucial role. The current study has not only led to more effective and selective synthetic methods for B11H14−and B12H122−but also unveiled the nature of the B–H bond condensation and the general formation mechanisms of polyhedral boranes. This finding will facilitate the development of more effective synthetic methods for polyhedral boranes and spur their wide application.

ABSTRACTThe external windshield is a key component in high-speed trains for drag reduction. However, the installation gap between external windshields, which is intended for improving curve-passing ability, could lead to strong aerodynamic instability in train-end area and therefore significant operating risk for train. This study aims to advance this field based on detailed numerical simulation, investigating the related flow features in this area, particularly from a time-dependent perspective. Flow field around external windshields with different installation gaps (10, 20 and 30 mm) is resolved based on Improved Delayed Detached Eddy Simulation (IDDES). The aerodynamic forces on different windshield components, turbulent flow fields around the train-end area, and corresponding low-dimensional modes are analyzed. The results show that the difference in the external windshield gap can significantly affect the related aerodynamic forces, with the 20 mm case having the highest time-averaged values. The aerodynamic spectrum shows primary, secondary and tertiary peak frequencies with a relatively high power spectral density (PSD). Decreasing the gap distance generally increases the overall PSD in the Strouhal number ranges considered, particularly for the secondary and tertiary peaks. The load forms and their energy distributions under different external windshield gaps are obtained through the proper orthogonal decomposition analysis.

The specific recognition and separation of alkanes with similar molecular structures and close boiling points face significant scientific challenges and industrial demands. Here, rectangular carborane-based metallacycles were designed to selectively encapsulate n-pentane from n-pentane, iso-pentane, and cyclo-pentane mixtures in a simple-to-operate and more energy-efficient way. Metallacycle 1, bearing 1,2-di(4-pyridyl) ethylene, can selectively separate n-pentane from these three-component mixtures with a purity of 97%. The selectivity is ascribed to the capture of the preferred guest with matching size, C–H···π interactions, and potential B–Hδ−···Hδ+–C interactions. Besides, the removal of n-pentane gives rise to original guest-free carborane-based metallacycles, which can be recycled without losing performance. Considering the variety of substituted carborane derivatives, metal ions, and organic linkers, these new carborane-based supramolecular coordination complexes (SCCs) may be broadly applicable to other challenging recognition and separation systems with good performance.

Ion adsorption and hydrogen bond (HB) network reconstruction in electric double layer (EDL) have a profound impact on the interface properties. The microstructure in the bulk phase of 1.00–21.30 wt.% Na2SO3aqueous solutions are investigated by X-ray scattering, confocal Raman spectroscopy, and classical molecular dynamics. The electronic properties of SO32-adsorption and the geometric structure of the HB network in the EDL at the titanium TiO2(101) surface are studied by density functional theory (DFT) and classical molecular dynamics. The SO32–strongly weakens the fully hydrogen-bonded water (FHW) and transforms it into partial hydrogen-bonded water (PHW). The HB transformation index (HBTI = PHW/FHW) shows a linear relationship with the mass fraction of Na2SO3. The TiOb-parallel adsorption configuration of SO32-enhances the ionicity of the Ob–Ti6bond, resulting in the formation of oxygen vacancies at the titanium passive film surface. Besides, SO32-and Na+are enriched and thermodynamic supersaturated in the inner Helmholtz layer (IHL), and the ions are diluted in the outer Helmholtz layer (OHL). The diffusion coefficient of SO32-and water molecules in EDL decreases seriously, which is easy to causes salt scaling on the surface of titanium passive film. This work provides evidence for the destruction of titanium passive film by SO32-.

Non-alcoholic fatty liver disease (NAFLD) is highly prevalent in children and adolescents, particularly those with obesity. NAFLD is considered a hepatic manifestation of the metabolic syndrome due to its close associations with abdominal obesity, insulin resistance, and atherogenic dyslipidemia. Experts have proposed an alternative terminology, metabolic dysfunction-associated fatty liver disease (MAFLD), to better reflect its pathophysiology. This study aimed to develop consensus statements and recommendations for pediatric MAFLD through collaboration among international experts.