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关键词： Rock fracture   Shear mechanical characteristics   Roughness index   DEM   Shear test  

摘要： Rough feature quantitatively described by the roughness indexes is the key to evaluating the shear mechanical characteristics of rock fractures in advance. However, the correspondence between roughness index and fracture shear mechanical characteristics has not been verified. In this study, the specific relationship between the roughness index theta*max/(C + 1) and the shear mechanical characteristics of rock fractures was discussed through numerical direct shear tests of fracture specimens based on the discrete element method (DEM). To explore this, rough rock fractures having the same theta*max/(C + 1) were established by adjusting the ten standard roughness profiles. The microscopic mechanics parameters of the rock and fracture in the numerical model were determined by calibrating the macroscopic parameters with physical model experiments. The test results show that fracture specimens with the same roughness grade exhibit varying shear mechanics indicators, with the degree of dispersion increasing as the roughness increases. However, due to differences in morphology, specimens with the same roughness grade exhibit distinct contact force distribution and failure characteristics. It has been observed that theta*max/(C + 1) can well reflect the roughness grade and even macroscopic shear properties of fractures when discretisation is not taken into account.

关键词： α,ω-Diphenylpolyenes   Fluorescence spectroscopy   UV–Vis absorption   TD-DFT calculations   Vibronic simulations   1,6-Diphenyl-1,3, 5-hexatriene (DPH) rotamers   Conformational equilibrium  

摘要： We present experimental and theoretical evidence indicating that the widely accepted assignment of two 1,6-diphenyl-1,3,5-hexatriene (DPH) rotamers in solution—an all-trans form and an s-cis form—must be reconsidered. High-quality absorption and fluorescence spectra of DPH in n-heptane, together with vibronically resolved simulated spectra based on TD-DFT (PBE0/def2-TZVP) calculations, show that the experimental spectra, including the “pure” component bands previously attributed to distinct conformers, are consistently reproduced by a single ttt-DPH rotamer. In contrast, computed spectra for the s-cis rotamer are clearly red-shifted and essentially structureless, and no such signature is observed in our experimental spectra. Thermodynamic and kinetic considerations further indicate that the s-cis form is a minor, spectroscopically marginal species over the investigated temperature range. Overall, these results provide an alternative interpretation to the long-standing conformer-based assignment of DPH solution spectra and highlight the importance of combining electronic-structure calculations with absorption and emission spectroscopy for reliable conformer-specific assignments in flexible polyenes and related chromophores.

关键词： Alternating direction method of multipliers   Compressed data separation   Restricted isometry property   Signal recovery   ℓ1−βℓq Minimization  

摘要： This paper explores the effectiveness of the ${\ell }_1-\beta {\ell }_q$ minimization approach for compressed data separation. We propose a novel framework that leverages the robustness of ℓ₁ regularization and the sparsity-promoting properties of the ℓ_q norm to offer enhanced flexibility. Building on the Dantzig Selector, we introduce an extended model incorporating ${\ell }_1-\beta {\ell }_q$ decomposition analysis. Under the D-RIP(D-restricted isometry property), we show that this method can effectively recover sparse signals from compressive measurements under two types of noise. An ADMM-based algorithm for solving the ${\ell }_1-\beta {\ell }_q$ model is developed to solve the optimization problem, and numerical experiments demonstrate its superior reconstruction accuracy and stability compared to existing methods.

关键词： Absorption   Amino acid   Carbon capture   CESAR solvent   L-lysine  

摘要： Carbon capture technologies are vital for mitigating carbon dioxide (CO₂) emissions in bioenergy and energy-from-waste power plants. Among them, solvent-based absorption is the most widely used in above industries. Mono-ethanolamine (MEA) is the pre-dominant and an established solvent for absorption based-carbon capture. However, newer solvent blends, like mixtures of MEA and N-methyl diethanolamine (MDEA), and CESAR-1 (a blend of 2-amino-2-methyl-1-propanol and piperazine) are being considered for future plants as they offer 10–15% enhanced performance and ∼20% improved capacity. This study presents the first results of adding L-lysine as a co-promoter for CESAR-1, to improve its CO₂ capture efficiency and capacity. The proposed blend, Bio-CESAR (a blend of 2-amino-2-methyl-1-propanol, piperazine, and L-lysine), was experimentally tested for CO₂ solubility across a range of pressures (30–500 kPa, CO₂ partial pressure range of 3–50 kPa) and temperatures (298.15–343.15 K), and its performance was compared to conventional CESAR-1 and MEA solutions. Results show that Bio-CESAR offers 15% higher CO₂ loading and equilibrium CO₂ solubility at average compared to CESAR-1, suggesting potential for improved cyclic efficiency in industrial applications. The enhanced CO₂ absorption performance of Bio-CESAR is attributed to the incorporation of L-lysine, which modifies CO₂–solvent interactions and solution speciation within the CESAR-1 framework. Results from this macroscopic study suggest that the bio-derived amino acid act synergistically with the conventional amine components, leading to improved equilibrium CO₂ loading. This study provides a fundamental insight for the use of L-lysine (and not its alkaline salt) in enhancing solvent performance and reducing environmental risks in carbon capture systems.

关键词： Adsorption   Heterogeneous catalysis   Hierarchical titanosilicalite-1   Oxidative desulfurization   Silver oxide  

摘要： To address the mass transfer limitations and adsorption constraints in deep desulfurization processes, a novel bifunctional catalyst, Ag₂O/HTS-1, was synthesized and evaluated for the oxidative desulfurization (ODS) of model fuels. The catalyst was prepared by hydrothermally synthesizing hierarchical titanosilicalite-1 (HTS-1) using polydiallyldimethylammonium chloride as a mesopore-directing agent, followed by the strategic impregnation of Ag₂O. Comprehensive physicochemical characterization confirmed the successful integration of Ag species onto a stable, hierarchically porous MFI framework. The resulting catalyst leverages a powerful synergistic effect. The enlarged mesopores of HTS-1 overcome diffusion barriers for bulky sulfur compounds, while the Ag sites serve as preferential adsorption sites. Consequently, under optimal conditions (60 °C, 2:1 oxidant-to-sulfur molar ratio), Ag₂O/HTS-1 demonstrated superior performance, achieving 100% desulfurization of DBT and 98% desulfurization of bulky 4,6-DMDBT, significantly surpassing conventional TS-1 and HTS-1 catalysts. Demonstrating industrial viability, the catalyst maintained robust performance in the presence of common interfering fuel components and exhibited high activity over five reaction cycles. These results highlight Ag₂O/HTS-1 as a highly efficient and reusable bifunctional catalyst, capable of simultaneously promoting oxidation and adsorption for the sustainable production of clean fuels.

关键词： tuberculosis infection   1HP   rifapentine concentration   pediatrics   safety  

摘要： Background One month of daily rifapentine plus isoniazid (1HP) is a new regimen for tuberculosis (TB) infection to lower the incidence of active TB. However, it has not been prescribed for Chinese children, and the optimal dosage of daily rifapentine for children remains controversial. We aimed to assess the feasibility and safety of 1HP in young Chinese children with TB infection and to provide evidence for extrapolating dosing strategies to children. Methods An open-label, prospective, single-arm clinical trial was conducted among eligible participants (aged <= 14 years). Completion rate, safety, and rifapentine concentrations of the 1HP regimen were analyzed. Results Eighty children were enrolled in our study;79 of the participants (98.75%) completed the treatment, with only 1 case of noncompletion (1.25%) in the age group 6-14 years because of rash. Five of 80 participants (6.25%) experienced grade >= 3 adverse events, with no serious adverse events or deaths reported. The relationship between rifapentine concentration (mg/L) and time (days) in children stratified by age and weight demonstrated the lowest rifapentine concentration in participants <= 2 years old and those weighing <= 15 kg when compared to the other subgroups. Conclusions The 1HP regimen is safe and feasible for young Chinese children with TB infection. Weight-based daily rifapentine (10-15 mg/kg) might not be enough for young children, particularly for those aged <= 2 years or weighing <= 15 kg. Clinical Trials Registration ChiCTR2200066411.

关键词： Atom transfer radical polymerization   CYFRA21-1   FRET biosensor   Upconversion nanoparticles  

摘要： The rapid and sensitive detection of cytokeratin 19 fragment (CYFRA21-1) is essential for the early screening and diagnosis of lung cancer. Herein, we developed a novel fluorescence resonance energy transfer (FRET) biosensor based on upconversion nanoparticles (UCNPs), incorporating an atom transfer radical polymerization (ATRP) signal amplification strategy for the rapid and sensitive detection of CYFRA21-1. The FRET biosensor employs UCNPs, which exhibit a low biological background signal and high quantum yield, as the energy donor, and gold nanoparticles (AuNPs) as the energy acceptor. The distance between the energy donor and acceptor is reduced through specific antigen/antibody interactions, leading to the quenching of the donor luminescence signal. The grafting of UCNPs on specific antibodies via ATRP can significantly enhance the quenching of fluorescence signal, thus improving the detection sensitivity. Under optimal conditions, the biosensor demonstrated a linear range of 1 ng/mL ∼ 60 ng/mL with a detection limit of 0.66 ng/mL. Furthermore, the biosensor exhibited high accuracy, selectivity, and robust anti-interference capabilities in the presence of complex biological matrices. This versatile sensing platform can be readily adapted for various targets, holding great promise for applications in medical diagnostics, environmental monitoring, and food safety.

关键词： Apoptosis   spheroid   PAC-1   glioma   caspase  

摘要： Glioblastoma multiforme (GBM) is the most common form of malignant brain cancer and is generally approached with palliative intent. Preclinical studies suggest that short-term fasting may be an effective tool for enhancing existing cancer therapies by disrupting the glucose-dependent, oncogenic phenotype of many cancers. In this study, we investigated whether a fasting-mimicking environment (FME) enhances the efficacy of an emerging proapoptotic drug, procaspase-activating compound 1 (PAC-1 in 2D and 3D GBM cell models. Ad libitum food consumption (Fed) and FME conditions were simulated in vitro by modifying glucose, ketone and serum concentrations. The FME conditions enhanced PAC-1 in U87-MG, T98G and 9L-GS monolayer experiments by significantly reducing the PAC-1 50% inhibitory concentration (IC50 delaying cell growth and increasing apoptosis. Similarly, in the 3D spheroid models, the minimum concentration of PAC-1 required to reduce U87-MG and 9L-GS spheroid area was lower in the FME conditions than the Fed conditions. Additionally, we discovered that serum restriction was primarily responsible for the FME-induced PAC-1 enhancement. These finding are the first to demonstrate that fasting-mimicking conditions sensitize 2D and 3D glioma cell models to PAC-1, supporting the use of short-term fasting as a low-cost and widely accessible strategy for enhancing cancer therapies.

关键词： (2+1)D combined power nonlinear Schrödinger equation   2D soliton   Crank-Nicolson finite difference   Nonlinear damping  

摘要： Although the (2+1)D nonlinear Schrödinger equation with combined power-type nonlinearities is known to prevent critical and supercritical collapse, existing numerical analyses are largely restricted to specific cases. We propose a Crank-Nicolson finite difference scheme for the (2+1)D nonlinear Schrödinger equation with mixed focusing-defocusing power-law nonlinearities and generalized damping. Using a discrete Gagliardo-Nirenberg inequality and appropriate energy estimates, we rigorously establish the existence, uniqueness, and boundedness of the discrete solution in the L²- and H¹-norms. Moreover, we derive optimal second-order convergence rates in both space and time, with error estimates provided in the L² and H¹ discrete norms. We also show that the numerical scheme conserves discrete energy when $\epsilon =0$. Numerical experiments validate our theoretical results and confirm the accuracy and robustness of the proposed scheme across a range of nonlinear exponents.