Chemical Mechanism Research Articles

Large eddy simulation of soot formation in a turbulent lifted flame with a discretized population balance and a reduced kinetic mechanism

This article presents simulations of a turbulent lifted flame using the large eddy simulation-transport probability density function-discretized population balance equation approach. This approach takes into account the interaction between turbulent reacting flow and soot particle formation. A reduced chemical kinetics mechanism including a series of polycyclic aromatic hydrocarbons (PAHs) species linked to soot formation is generated employing the approach of the directed relation graph error propagation and is tested on a perfectly stirred reactor under varying equivalent ratio conditions and premixed flames. The soot kinetics model includes the PAH-based nucleation and surface condensation, the hydrogen abstraction acetylene addition surface growth and oxidation mechanism, and the size-dependent aggregation. The soot morphology considers the surface area and other geometrical properties for both spherical primary particles and fractal aggregates. The simulation results show, in general, reasonably good agreement with experimental measurements in terms of lifted height, flame shape, flow-field velocity, the hydroxyl radical, and soot volume fraction. A discussion of micromixing and its modeling in the context of the Interaction by Exchange with the Mean model is also presented. To investigate the effect of the soot micromixing frequency factor on soot particles, an additional simulation is conducted where this factor is reduced by a factor of 10 for the soot particles. The maximum soot volume fraction is observed to increase slightly. However, compared with the impact of kinetics on soot modeling, this effect is a minor one.

Numerical study on flow and combustion properties of oblique detonation engine in a wide speed range

Ensuring safe flight is a fundamental prerequisite for developing hypersonic propulsion systems. A comprehensive investigation of the steady boundary associated with oblique detonation wave in a wide speed range was conducted, with the aim of exploring the feasibility of oblique detonation engine across a diverse array of flight conditions. In this study, the wedge angle applicable in a wide-speed range was acquired via the analysis of oblique detonation wave polar curve. The configuration of the internal injection oblique detonation engine was subsequently designed and established, considering the effect of fuel-air inhomogeneity and complex wave system interactions within a confined combustor. The compressible Euler equations coupled with a 9-species and 19-step chemical reaction mechanism are employed to simulate the oblique detonation process. Ultimately, the safe flight envelope of an air-breathing vehicle equipped with the internal injection oblique detonation engine is mapped across a broad range of Mach numbers, demonstrating the engine’s capability to operate within the Mach 8 to 12 range. Furthermore, the findings reveal that decreasing either the flight Mach number or altitude results in unsteady oblique detonation wave within the internal injection oblique detonation engine combustor, however, reducing the equivalence ratio can stabilize the oblique detonation wave once again. This study provides valuable guidance for the design and wide-speed-range operation of an internal injection oblique detonation engine.

Surface electric fields-enhanced biochar: A dual-action adsorbent and PMS activator for sulfamethoxazole removal

Integrating adsorption with advanced oxidation processes offers significant advantages over conventional single-stage wastewater treatment methodologies. Herein, this study successfully synthesized nitrogen-boron codoped metal-free biochar at 700 °C (700NBBC). 700NBBC effectively eliminates sulfamethoxazole (SMX) from water through a synergistic adsorption-oxidation process, showcasing robust resistance to interference and broad pH tolerance. Characterizations and experimental outcomes indicate that 700NBBC primarily adsorbs SMX through a monolayer surface chemical adsorption mechanism and activates persulfate (PMS) to oxidize SMX via a non-radical mechanism, which includes the generation of singlet oxygen (1O2) and electron transfer processes. Density functional theory calculations elucidate that N and B doping regulate the local electronic environment at biochar surface, enhancing the adsorption energy between biochar and PMS while effectively catalyzing PMS cleavage to generate 1O2. This research offers fresh perspectives on the critical role of heteroatom doping in regulating reactive oxygen species generation within biochar.

VOLATILE ANTIDIABETIC PROPERTIES OF PIPER NIGRUM L. ETHANOL EXTRACT (ORIGINAL AND PLANT STEM CELL): NETWORK PHARMACOLOGY STUDY AND ANTIOXIDANT ACTIVITY

Objective: This study aims to identify and compare the active chemical components in the ethanol extracts of Piper nigrum L. (black pepper) plant and its callus and to investigate their potential roles in treating diabetes mellitus through Protein-Protein Interaction (PPI) analysis. Methods: Ethanol extracts were prepared from both the original black pepper plant and its callus. Chemical analysis identified key active substances, including piperine and β-D-Glucopyranoside, using Retention Times (RT). PPI investigations were conducted to determine the interactions involved in diabetes management. The antioxidant capacities of the extracts were assessed using IC50 values, and the biological processes and molecular functions related to diabetes treatment were evaluated. Results: Both the original plant and callus extracts contained active substances such as piperine (37.715%, RT: 28.1967) and β-D-Glucopyranoside (54.272%, RT: 16.5768). The primary biological processes identified were the P450 epoxygenase pathway and glycogen production. Additionally, the organic acid metabolic process and nucleosome core were implicated in the management of diabetes mellitus by the extracts. The main molecular functions predicted were p53 binding and cyclin. The antioxidant capacities of the extracts were moderate for the callus extract (IC50: 129.92±0.83) and poor for the original plant extract (IC50: 156.69±1.36). Conclusion: The study reveals that the ethanol extracts from the black pepper callus and the original plant possess distinct chemical profiles and mechanisms in treating diabetes mellitus. The callus extract demonstrates a more favorable antioxidant capacity compared to the original plant extract. Both extracts engage in similar biological processes but exhibit differences in their chemical composition and potential therapeutic pathways for diabetes management.

A Study on a New Method for Simultaneous Internal Curing and hydrophobic in Concrete

The high hydrophilicity and permeability of concrete caused by many pores and hydroxyl groups produced by cement hydration are the main factors leading to dry shrinkage, cracking, and poor corrosion resistance of concrete. Giving concrete internal curing and hydrophobicity is an effective measure to solve the above problems. In this paper, a new idea and preparation method for an organic combination of hydrophilic and hydrophobic materials are proposed to improve the service life of concrete structures. Furthermore, the combined effects of hydrophilic and hydrophobic amphoteric materials (HAM) on the mechanical properties, internal curing properties, and hydrophobic properties of concrete were comprehensively investigated. In addition, the physical and chemical action mechanisms were analyzed in conjunction with microscopic tests. The results indicated that HAM rapidly released water within 3-7 days before concrete curing, and then slowly released water accompanied by the release of hydrophobic materials, gradually from hydrophilic to hydrophobic properties; The addition of HAM did not reduce the mechanical properties of concrete, which solved the problem of low compressive strength of integral hydrophobic concrete; The addition of HAM reduced the drying shrinkage of concrete by 154.12%, increased the contact angle to 96°, and decreased the water absorption rate by 36%, allowing the concrete to achieve better internal curing and a hydrophobic effect. The preparation of this material can open up a new way to solve the hydrophilic and hydrophobic properties required by concrete at the same time, and fill the gap that concrete can not balance hydrophilic and hydrophobic properties.

Experimental study on droplet dynamics behavior and combustion characteristics of high performance green propellant in electrical ignition mode

High performance green propellant represented by ammonium dinitramide-based liquid propellant and its new ignition method are the research hotspots of space propulsion in the 21st century. Exploring the complex multi-scale physical properties of multi-component ammonium dinitramide-based liquid propellant droplets in the electrical ignition mode has wide application significance for spray, propulsion system design and combustion control. The droplet dynamics behavior and combustion characteristics of propellant droplets at different ignition voltages were studied experimentally. The droplet dynamics behavior during the evaporation process, including violent volume oscillation, approximate steady-state expansion, contraction, secondary expansion, puffing and micro-explosion, have been determined by the generation, growth, and discharge of vapor bubbles. In the initial evaporation process, the heterogeneous nucleation is dominant. As the droplet is continuously heated, homogenization nucleation gradually dominates. The main physical and chemical mechanisms of bubble evolution driven by temperature involve methanol boiling, water overheating, ammonium dinitramide decomposition and combustion reaction between vapor molecules. Increasing the ignition voltage increases the droplet dynamics behavior and the combustion, but promotes the combustion instability. Increasing the ignition voltage increases the ignition delay time, puffing delay time, droplet lifetime, maximum temperature of droplet, and reduces the ignition critical diameter. It is proposed that the method of suppressing the droplet breakup dynamics at decomposition area and enhancing the droplet breakup dynamics at the combustion area are conducive to the combustion control of the thruster in electrical ignition mode. This research provides novel insight into the study of the electrical ignition mechanism of liquid fuels.

Molecular Mechanisms of Polyphenols in Management of Skin Aging.

The natural process of skin aging is influenced by a variety of factors, including oxidative stress, inflammation, collagen degradation, and UV radiation exposure. The potential of polyphenols in controlling skin aging has been the subject of much investigation throughout the years. Due to their complex molecular pathways, polyphenols, a broad class of bioactive substances present in large quantities in plants, have emerged as attractive candidates for skin anti-aging therapies. This review aims to provide a comprehensive overview of the molecular mechanisms through which polyphenols exert their anti-aging effects on the skin. Various chemical mechanisms contribute to reducing skin aging signs and maintaining a vibrant appearance. These mechanisms include UV protection, moisturization, hydration, stimulation of collagen synthesis, antioxidant activity, and anti-inflammatory actions. These mechanisms work together to reduce signs of aging and keep the skin looking youthful. Polyphenols, with their antioxidant properties, are particularly noteworthy. They can neutralize free radicals, lessening oxidative stress that might otherwise cause collagen breakdown and DNA damage. The anti-inflammatory effects of polyphenols are explored, focusing on their ability to suppress pro-inflammatory cytokines and enzymes, thereby alleviating inflammation and its detrimental effects on the skin. Understanding these mechanisms can guide future research and development, leading to the development of innovative polyphenol-based strategies for maintaining healthy skin.

Adsorption behavior and quantum chemical analysis of surface functionalized polystyrene nano-plastics on gatifloxacin.

In this paper, the adsorption of gatifloxacin (GAT) by three types of polystyrene nano-plastics (PSNPs), including 400 nm polystyrene (PS), amino-modified PS (PS-NH2), and carboxyl-modified PS (PS-COOH) was studied and the adsorption mechanism were assessed. Experimental findings revealed that the equilibrium adsorption capacity of PSNPs to GAT followed the order PS-NH2 > PS-COOH > PS. The adsorption was regulated by both physical and chemical mechanisms, with intra-particle and external diffusion jointly controlling the adsorption rate. The adsorption process was heterogeneous, spontaneous, and entropy-driven. Sodium chloride (NaCl), alginic acid, copper ions (Cu2+), and zinc ions (Zn2+) inhibited adsorption, with Cu2+ and Zn2+ having the strongest effect on PS-NH2. Theoretical computations indicated that π-π and electrostatic interactions dominated PS adsorption of GAT, while PS-COOH and PS-NH2 adsorbed GAT through electrostatic interactions, hydrogen bonds, and van der Waals (vdW) forces. The surface electrostatic potential of PS-COOH and PS-NH2 was considerably higher than that of PS, with the maximum vdW penetration distance of GAT-PS-NH2 being 1.20 Å. This study's findings provide a theoretical foundation for the migration and synergistic removal of antibiotics, micro-plastics (MPs), and nano-plastics (NPs).

Defect-Engineered Coordination Compound Nanoparticles Based on Prussian Blue Analogues for Surface-Enhanced Raman Spectroscopy.

Surface-enhanced Raman spectroscopy (SERS) is a powerful tool for label-free chemical analysis. The emergence of nonmetallic materials as SERS substrates, offering chemical signal enhancements, presents an exciting direction for achieving reproducible and biocompatible SERS, a challenge with traditional metallic substrates. Despite the potential, the realm of nonmetallic SERS substrates, particularly nanoparticles, remains largely untapped. Here, we present defect-engineered coordination compounds (DECCs) based on Prussian blue analogues (PBAs) as a class of nonmetallic nanoparticle-based SERS substrates. We demonstrate the utility and flexibility of the DECC template by incorporating various metal (M) elements into PBAs to synthesize nanoparticles that deliver substantial chemical mechanism (CM)-based enhancements to the Raman signal with a ∼ 108-fold increase. The introduction of the M-PBA-based DECC nanoparticles as a class of SERS substrates represents a pioneering stride, enabling the straightforward and systematic exploration of a library of compounds for SERS-based analysis of a wide range of target molecules, especially biomolecules.

Simple Parameters and Data Processing for Better Signal-to-Noise and Temporal Resolution in In Situ 1D NMR Reaction Monitoring.

In situ 1D NMR spectroscopic reaction monitoring allows detailed investigation of chemical kinetics and mechanism. Concentration versus time data are derived from a time series of NMR spectra. Each spectrum in the series is obtained by Fourier transform of the corresponding FID. When the spectrometer outputs FIDs recorded from multiple scans, the spectra benefit from an increase in signal-to-noise (S/N). However, this reduces the number of FIDs and, thus, kinetic data points. We report a simple alternative in which the same number of scans is acquired by the spectrometer, but each scan is saved independently. Signal averaging is then conducted by postacquisition processing. This leads to an increase in both the S/N and the number of kinetic data points and can avoid "overaveraging" effects. The entire series of single-scan FIDs spanning the reaction lifetime can be summed to yield a "total reaction spectrum" in which intermediates can be identified. The method can be applied in coherence with phase cycling to minimize spectral distortion during solvent signal suppression. Overall, the approach simplifies the preacquisition parameters to the estimation of the reaction duration and T1max and then the selection of the pulse angle, θ, and scan repetition time, τR, without the need to set the signal averaging before the experiment.

Revealing the flame inhibition effect of phytic acid (PA) by PIV measurements and detailed chemical kinetic modeling of counterflow CH4/PA/air flames

As industrialization continues to deepen, polymers have become ubiquitous in daily life. However, their flammable characteristics pose significant safety risks. Therefore, supporting the global goal of sustainable development necessitates the development of high-performance, environmentally friendly flame retardants. Biomass phytic acid (PA) has emerged as a promising option because of its high phosphorus content and excellent biocompatibility. However, its combustion behaviors and chemical kinetic mechanisms remain unclear. In this study, quantum chemical calculation methods were used to construct a detailed PA chemical reaction kinetic model. A series of experiments were conducted to validate the model and evaluate PA's flame suppression effect. Utilizing a counterflow flame burner and particle image velocimetry (PIV), the inhibitory effect of various PA concentrations was examined based on the laminar flame speed of CH4/PA/Air mixture. The results revealed that a merely 0.2 % addition of PA could reduce the laminar flame speed by 38.9 %, demonstrating its significant flame suppression effect. Building on the foundational GRI-Mech 3.0 and integrating PA's pyrolysis and reaction mechanism, this study developed for the first time a detailed chemical model of CH4/PA/Air combustion. This model integrated PA's thermal decomposition module and thermodynamic data via ab-initio quantum chemical calculations, thereby accurately predicting global kinetic indicators such as laminar flame speed. Results suggested that the key reactions, such as PO2+H + M→HOPO + M, HOPO2+H→PO2+H2O, and HOPO + OH→PO2+H2O primarily influenced the laminar flame speed. Moreover, the CFD simulation elucidated the complex interaction between PA and flame structures. A detailed analysis of the spatial distribution of key parameters such as temperature, combustion radicals, and effective inhibition radicals unveiled the PA's flame suppression mechanism in support of the practical application of this eco-friendly flame retardant.

Effect of chemical consolidation on physico-mechanical properties of porous coral reef limestone

Porous coral reef limestone (CRL) is characterized by the low strength and developed pore structure, so improving its physico-mechanical properties is important for marine engineering construction work. Chemically consolidated porous CRL was prepared by taking a non-granular chemical grout (sodium silicate) as the main consolidation material. Then, the chemical consolidation effect was evaluated from two aspects (both the physical and mechanical properties) by conducting computed tomography (CT) scanning and quasi-static uniaxial compression tests. The results indicate that the consolidation material can fill the pores in the CRL, which reduces the porosity of specimens by more than 50%. In addition, the peak strength under quasi-static compression is increased by about 20%. The fragments decrease at failure, and fracture plane slip and crack opening are inhibited. Finally, influences of the special banded shape of consolidation material retained in the specimens on the failure process and failure mode of specimens were investigated. The chemical consolidation mechanism of porous CRL was revealed by combining with the scanning electron microscope (SEM) images. Research results indicate that the non-granular chemical material (sodium silicate) improves the physico-mechanical properties of porous CRL. The research provides reference for the foundation treatment in coral reefs and the design of consolidation schemes for surrounding rocks of underground spaces in marine engineering operations.

Experimental Investigation and Chemical Kinetics Analysis of Carbon Dioxide Inhibition on Hydrogen-Enriched Liquefied Petroleum Gas (LPG) Explosions

The utilization of hydrogen-enriched liquefied petroleum gas (LPG) is an effective means of reducing carbon emissions, but the special physical and chemical properties of hydrogen have raised concerns among the public. To delve into the intricate chemical kinetic mechanisms governing the inhibitory effect of CO2 on the explosion of hydrogen-enriched LPG, this study systematically investigated the influence of varying CO2 concentrations (3%, 6%, and 9%) on the explosion characteristics of hydrogen-enriched LPG (hydrogen ratio ranging from 0 to 0.5) within a 20 L spherical explosion chamber. Subsequently, a chemical kinetic analysis was conducted, focusing on the explosion reaction dynamics of the H2/LPG/CO2/Air mixture, encompassing temperature sensitivity assessments and the production rates of key free radicals. The findings reveal that although hydrogen incorporation does not significantly alter the maximum explosion pressure of LPG, it markedly accelerates the explosion reaction rate, posing a challenge for CO2 in effectively inhibiting the explosion of hydrogen-enriched LPG. CO2 functions as a stabilizing third body within the reaction system, diminishing the collision frequency among free radicals, hydrogen molecules, hydrocarbon molecules, and oxygen molecules, thereby slowing down the reaction rate. As the proportion of hydrogen increases, the concentration of ·H radicals, known for their high reactivity, escalates, rapidly completing the propagation phase of the chain reaction and intensifying the overall generation rates of critical free radicals, including ·H, ·O, and ·OH. Notably, the key reaction H+O2⇋O+OH, which governs the reaction temperature, undergoes significant enhancement, further accelerating the explosion reaction rate and ultimately diminishing the inhibitory efficacy of CO2 against the hydrogenated LPG explosion. Furthermore, as the amount of hydrogen added increases, hydrogen’s competitiveness for oxygen within the reaction system markedly improves, attenuating the oxidation of hydrocarbons. Concurrently, the alkane recombination reaction, exemplified by C3H6+CH3(+M)⇋sC4H9(+M), is strengthened. These insights provide valuable understanding of the complex interactions and mechanisms during the explosion of hydrogen-enriched LPG in the presence of CO2, with implications for the safe application of hydrogen-enriched LPG.

Ajuga orientalis L. Extract as a Green Corrosion Inhibitor of Aluminum in an Acidic Solution: An Experimental and DFT Study

The inhibitory effect of A. orientalis L. extract (AO) on aluminum corrosion in a 1.0 M HCl solution was investigated utilizing weight loss, electrochemical polarization, electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM). The results show that AO is a potent inhibitor in an acidic environment, and that the inhibition potency increases with concentration. Temperature investigations showed that, in an acidic medium, the efficiency decreased, increased, and then decreased as the temperature rose. Adsorption isotherms from Freundlich, Temkin, El Awady, and Redlich–Peterson (R-P) approximated the inhibitor’s adsorption properties. For the inhibitory behavior, a physical and chemical adsorption mechanism is proposed. The adsorption process’s thermodynamic parameters (Ea, ΔH*, and ΔS*) were determined and explained. The inhibitor, AO, was identified as a mixed-type (anodic and cathodic) inhibitor based on polarization studies. According to the SEM findings, the inhibitor partially covers the metal surface, providing it with a respectable level of protection. The weight loss, electrochemical polarization, EIS, scanning electron microscopy (SEM), and quantum chemical calculations show a strong agreement, indicating that the AO extract is a highly effective inhibitor of aluminum in an acidic solution.

Unveiling the chemical composition, antioxidant and antibacterial properties, and mechanistic insights of Convolvulus arvensis extract through molecular docking simulations

The use of herbal extracts has gained significant importance in modern health practices, making it essential to explore their properties and applications in detail. This study investigates the effect of ultrasound on the extraction yield of Convolvulus arvensis leaves, with a focus on its chemical composition, antioxidant properties, cytotoxicity, antimicrobial activities, and mechanism of action. Antimicrobial activity was determined using minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), well diffusion agar, and disk diffusion agar assays. The antioxidant properties were assessed through ferric reducing antioxidant power (FRAP) and DPPH free radical scavenging assays. High Performance Liquid Chromatography (HPLC) and Fourier transform infrared (FTIR) spectroscopy were utilized to identify the chemical composition and functional groups present in the extract. The findings revealed that ultrasound-assisted extraction exhibited significantly higher extraction efficiency (p < 0.05). The extract displayed significant antimicrobial activity against Listeria innocua, Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus. The total phenolic and total flavonoid contents of the extract were measured at 328.85 ± 0.046 (mg GAE/100 g) and 226.23 ± 0.043 (mg QE/100 g), respectively. Moreover, the extract demonstrated notable radical scavenging activity against DPPH, with a value of 37.40 ± 0.111 (g/100 g). The FRAP assay revealed that the antioxidant activity of C. arvensis extract was quantified at 23.796 ± 0.045 μmol Fe²⁺. The highest amount of phenolic and alkaloid compounds in the extract was related to β-Phellandrene (341.52 µg/mL) and Swainsonine (360.24 µg/mL), respectively. Furthermore, the in vitro cytotoxic activity of the extract was evaluated against the Caco-2 cell line, with the IC50 value determined to be 26.55 mg/mL. The results of the docking study demonstrated that Ferulic acid displayed a significant binding energy of −6.2 kcal/mol, suggesting a robust interaction with the target enzyme and the potential to act as a modulator of glutathione peroxidases. The findings of the present study revealed that the alcoholic extract of C. arvensis possesses proper antioxidant and antimicrobial activities. Therefore, it has been used as a food preservative. However, further medical and clinical researches are required before any application in human health.

Recent Advances in Antibacterial Strategies Based on TiO2 Biomimetic Micro/Nano-Structured Surfaces Fabricated Using the Hydrothermal Method

Ti and its alloys, widely utilized in orthopedic and dental implants, inherently lack antibacterial properties, posing significant infection risks, especially in the context of growing antibiotic resistance. This review critically evaluates non-antibiotic antibacterial strategies, with a particular focus on surface modifications and micro/nano-structured surfaces. Micro/nano-structured surfaces, inspired by natural topographies, utilize physical mechanisms to eradicate bacteria. Despite their potential, the antibacterial efficacy of these surfaces remains insufficient for clinical application. Titanium dioxide (TiO2), known for its excellent photocatalytic antibacterial activity and biocompatibility, is emerging as an ideal candidate for enhancing micro/nano-structured surfaces. By combining the photocatalytic antibacterial effects of TiO2 with the mechanical bactericidal properties of micro/nano-structured surfaces, superior antibacterial performance can be achieved. The hydrothermal method is frequently employed to fabricate TiO2 micro/nano-structured surfaces, and this area of research continues to thrive, particularly in the development of antibacterial strategies. With demonstrated efficacy, combined antibacterial strategies based on TiO2 micro/nano-structured surfaces have become a prominent focus in current research. Consequently, the integration of physical stimulation and chemical release mechanisms may represent the future direction for TiO2 micro/nano-structured surfaces. This review aims to advance the study of TiO2 micro/nano-structured surfaces in antibacterial applications and to inspire more effective non-antibiotic antibacterial solutions.

Tailoring Hematite Photoanodes for Improved PEC Performance: The Role of Alcohol Species Revealed by SHAP Analysis.

We explore the synergistic effects of TiO2 underlayers and varied alcohol species in the precursor solutions on the photoelectrochemical (PEC) performance of hematite photoanodes. Utilizing a robust machine learning (ML) framework combined with comprehensive analytical data sets, we systematically investigate how these modifications influence key physical and chemical properties, directly impacting the efficiency of water splitting processes. Our approach employs an ML model that integrates SHapley Additive exPlanations (SHAP) to quantitatively assess the impact of each dominant descriptor selected in the analytical data on the PEC performance, and they were combined with the SHAP values' dependence on the experimental operations. Specifically, we focus on the type of alcohol (methanol, ethanol, butanol, and 2-ethyl-1-butanol) used in the precursor solutions as the experimental operation, examining their effects on the dominant descriptors selected in the analytical data. The results from the SHAP analysis reveal that different alcohol species significantly alter the physicochemical properties at the hematite/TiO2 interface and in bulk hematite. These changes are primarily manifested in the modulation of the density of states and resistance to promote the charge carrier transport. For example, ethanol and butanol were found to enhance the electron density of states at the interface, which correlates with higher photocurrent outputs and improved PEC activity. In contrast, methanol showed a less pronounced effect, suggesting a nuanced interaction between the alcohol molecular structure and hematite surface chemistry. These findings not only underscore the importance of tailored precursor solution chemistry for enhancing PEC performance but also highlight the power of ML tools in uncovering the underlying physical and chemical mechanisms that govern the behavior of complex material systems. This study sets a foundational approach where ML can bridge the gap between empirical observations and theoretical understanding, leading to the rational design of energy materials.

Banxia xiexin decoction prevents the development of gastric cancer.

In China banxia xiexin decoction (BXD) has been used in treating gastric cancer (GC) for thousands of years and BXD has a good role in reversing GC histopathology, but its chemical composition and action mechanism are still unknown. To investigate the mechanism of action of BXD against GC based on transcriptomics, network pharmacology, in vivo and in vitro experiments. The transplanted tumor model was prepared, and the nude mouse were pathologically examined after administration, and hematoxylin-eosin staining was performed. The active ingredients of BXD were quality controlled and identified using ultra-performance liquid chromatography tandem quadrupole electrostatic field orbitrap mass spectrometry (UPLC-Q-Orbitrap MS/MS), and traditional Chinese medicines systems pharmacology platform, drug bank and the Swiss target prediction platform to predict the relevant targets, the differentially expressed genes (DEGs) of GC were screened by RNA-seq sequencing, and the overlapping targets were analyzed to obtain the key targets and pathways. Cell Counting Kit-8, apoptosis assay, cell migration and Realtime fluorescence quantitative polymerase chain reaction were used for in vitro experiments. All dosing groups inhibited the growth of transplanted tumors in laboratory-bred strain nude, with the capecitabine group and the BXD medium-dose group being the best. A total of 29 compounds and 859 potential targets in BXD were identified by UPLC-Q-Orbitrap MS/MS and network pharmacology, RNA-seq sequencing found 4767 GC DEGs, which were combined with network pharmacology and analyzed 246 potential therapeutic targets were obtained and pathway results showed that BXD may against GC through the Phosphoinositide 3-kinase (PI3K)/protein kinase B (AKt) signaling pathway. In vitro cellular experiments confirmed that BXD-containing serum and LY294002 could inhibit the proliferation of GC cells, promote apoptosis, and inhibit the migration of GC cells by decreasing the expression of EGFR, PIK3CA, IL6, BCL2 and AKT1 in the PI3K-Akt pathway in MGC-803 expression. BXD has the effect of inhibiting tumor growth rate and delaying the development of GC. Its mechanism of action may be related to the regulation of PI3K-Akt signaling pathway.

Experimental and Kinetic Simulations of Technetium-Catalyzed Hydrazine Oxidation in Nitric Acid Solution

The catalytic reaction of Tc plays a significant role in the chemical separation process during spent fuel reprocessing. However, few studies have been conducted on the chemical reaction mechanism between Tc and hydrazine. Moreover, the instability of Tc(V) and Tc(VI) makes their measurement difficult, rendering many aspects of the reaction process and mechanism unclear. This study investigates the catalytic reaction between Tc and hydrazine in a nitric acid solution. To this end, we obtained the kinetic laws of the reaction under various conditions of acidity, hydrazine concentration, and Tc concentration by monitoring the concentrations of hydrazine and Tc(VII) over time. The reaction kinetics model demonstrated that numerical simulations could effectively predict the reaction process. Results indicated that hydrazine promotes the reduction of Tc(VII) to Tc(IV), constituting the basis for establishing the Tc(IV, V, VI, VII) catalytic cycle. Among these, Tc(V) and Tc(VI) were important active intermediates and the main consumers of hydrazine. The research results may be useful for actinide separation processes based on valence control.

Skeleton design engineering of covalent organic frameworks to enable in situ incorporation of coordination sites for improved extraction of uranyl ions

The development of advanced porous materials for effectively separating uranium from nuclear wastewater or seawater is a highly coveted yet formidable task. However, the importance of the covalent organic frameworks (COFs) skeletons and the specific arrangement of adjacent atoms is often disregarded when configuring coordination settings for chelating molecules. In this study, a novel material for oxygen-enriched COFs was developed. The optimized oxygen-rich COFs showed aligned neighboring bonds and triazine groups along the skeletons, resulting in an increase in uranyl binding sites and a threefold rise in the total number of binding sites. The synergistic interaction of ether bonds and triazine groups in the π-conjugated skeletons significantly reduced the energy band gap, leading to improved uranium affinity and recovery. The adsorption capacity reached an impressive 660 mg/g, surpassing that of most COF-based adsorbents using a chemical coordination mechanism in uranium-containing aqueous solutions. This study provides valuable insights into designing novel adsorbents for uranium separation.