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Bi/BiOCl with oxygen vacancies composite was synthesized through a facile and rapid in situ surface reduction of BiOCl, utilizing NaBH4 as the reductant. The reduction process yielded metallic Bi nanoparticles on the surface of BiOCl and meanwhile created the oxygen vacancies within the BiOCl lattice. As a consequence, the as‐synthesized Bi/BiOCl composites exhibited a substantially enhanced visible‐light absorption capacity, whereas pure BiOCl was only responsive to ultraviolet light. Additionally, the Bi/BiOCl composite demonstrated a markedly accelerated photodegradation rate of Rhodamine, exceeding that of pure BiOCl and P25 by a factor of 6.10 and 19.74, respectively. The density functional theory (DFT) calculation was carried out to estimate the band structural and electronic properties of samples. Based on systematic analysis, the underlying mechanism was attributed to the extended responsive light range due to the surface plasma resonance of metallic Bi and the formation of oxygen vacancy energy level. Moreover, the electron sink effect of Bi nanoparticles was found to suppress the recombination of photoinduced charges, further contributing to the enhanced photocatalytic performance of Bi/BiOCl. [ABSTRACT FROM AUTHOR]

The global prevalence of RNA virus infections has presented significant challenges to public health in recent years, necessitating the expansion of its alternative therapeutic library. Due to its evolutional conservation, RNA‐dependent RNA polymerase (RdRp) has emerged as a potential target for broad‐spectrum antiviral nucleoside analogues. However, after over half a century of structural modification, exploring unclaimed chemical space using frequently‐used structural substitution methods to design new nucleoside analogues is challenging. In this study, we explore the use of the "ring‐opening" strategy to design new base mimics, thereby using these base mimics to design new nucleoside analogues with broad‐spectrum antiviral activities. A total of 29 compounds were synthesized. Their activity against viral RdRp was initially screened using an influenza A virus RdRp high‐throughput screening model. Then, the antiviral activity of 38a was verified against influenza virus strain A/PR/8/34 (H1N1), demonstrating a 50% inhibitory concentration (IC50) value of 9.95 μM, which was superior to that of ribavirin (the positive control, IC50 = 11.43 μM). Moreover, 38a also has inhibitory activity against coronavirus 229E with an IC50 of 30.82 μM. In addition, compounds 42 and 46f exhibit an 82% inhibition rate against vesicular stomatitis virus at a concentration of 20 μM and hardly induce cytotoxicity in host cells. This work demonstrates the feasibility of designing nucleoside analogues with "ring‐opening" bases and suggests the "ring‐opening" nucleosides may have greater polarity, and designing prodrugs is an important aspect of optimizing their antiviral activity. Future research should focus on enhancing the conformational restriction of open‐loop bases to mimic Watson‐Crick base pairing better and improve antiviral activity. [ABSTRACT FROM AUTHOR]

This paper deals with the semigroup generation of anti‐triangular operator matrices M with unbounded entries in Hilbert space. Based on the space decomposition, some necessary and sufficient conditions are given for M to generate contraction semigroups. In addition, the anti‐triangular differential system, converted from the damping wave equation, is used to explain our work, and it is proved that the corresponding anti‐triangular operator matrix satisfies the conditions and generates a contraction semigroup. [ABSTRACT FROM AUTHOR]

Unmanned aerial vehicles (UAVs) equipped with remote-sensing object-detection devices are increasingly employed across diverse domains. However, the detection of small, densely-packed objects against complex backgrounds and at various scales presents a formidable challenge to conventional detection algorithms, exacerbated by the computational constraints of UAV-embedded systems that necessitate a delicate balance between detection speed and accuracy. To address these issues, this paper proposes the Efficient Multidimensional Global Feature Adaptive Fusion Network (MGFAFNET), an innovative detection method for UAV platforms. The novelties of our approach are threefold: Firstly, we introduce the Dual-Branch Multidimensional Aggregation Backbone Network (DBMA), an efficient architectural innovation that captures multidimensional global spatial interactions, significantly enhancing feature distinguishability for complex and occluded targets. Simultaneously, it reduces the computational burden typically associated with processing high-resolution imagery. Secondly, we construct the Dynamic Spatial Perception Feature Fusion Network (DSPF), which is tailored specifically to accommodate the notable scale variances encountered during UAV operation. By implementing a multi-layer dynamic spatial fusion coupled with feature-refinement modules, the network adeptly minimizes informational redundancy, leading to more efficient feature representation. Finally, our novel Localized Compensation Dual-Mask Distillation (LCDD) strategy is devised to adeptly translate the rich local and global features from the higher-capacity teacher network to the more resource-constrained student network, capturing both low-level spatial details and high-level semantic cues with unprecedented efficacy. The practicability and superior performance of our MGFAFNET are corroborated by a dedicated UAV detection platform, showcasing remarkable improvements over state-of-the-art object-detection methods, as demonstrated by rigorous evaluations conducted using the VisDrone2021 benchmark and a meticulously assembled proprietary dataset. [ABSTRACT FROM AUTHOR]

In recent years, caffeic acid and its derivatives have received increasing attention due to their obvious physiological activities and wide distribution in nature. In this paper, to clarify the status of research on plant-derived caffeic acid and its derivatives, nuclear magnetic resonance spectroscopy data and possible biosynthetic pathways of these compounds were collected from scientific databases (SciFinder, PubMed and China Knowledge). According to different types of substituents, 17 caffeic acid and its derivatives can be divided into the following classes: caffeoyl ester derivatives, caffeyltartaric acid, caffeic acid amide derivatives, caffeoyl shikimic acid, caffeoyl quinic acid, caffeoyl danshens and caffeoyl glycoside. Generalization of their 13C-NMR and 1H-NMR data revealed that acylation with caffeic acid to form esters involves acylation shifts, which increase the chemical shift values of the corresponding carbons and decrease the chemical shift values of the corresponding carbons of caffeoyl. Once the hydroxyl group is ester, the hydrogen signal connected to the same carbon shifts to the low field (1.1~1.6). The biosynthetic pathways were summarized, and it was found that caffeic acid and its derivatives are first synthesized in plants through the shikimic acid pathway, in which phenylalanine is deaminated to cinnamic acid and then transformed into caffeic acid and its derivatives. The purpose of this review is to provide a reference for further research on the rapid structural identification and biofabrication of caffeic acid and its derivatives. [ABSTRACT FROM AUTHOR]

We show that any (norm-closed two-sided) ideal of a unital C*-algebra that comes equipped with certain natural quantum metric structure is a metrized quantum vector bundle, when canonically viewed as a module over A. Next, given a unital AF-algebra A equipped with a faithful tracial state, we equip each ideal of A with a metrized quantum vector bundle structure using previous work of the first author and Latrémolière. Moreover, we show that convergence of ideals in the Fell topology implies convergence of the associated metrized quantum vector bundles in the modular Gromov-Hausdorff propinquity of Latrémolière. In a similar vein but requiring a different approach, given a compact metric space (X,d), we equip each ideal of C(X) with a metrized quantum vector bundle structure, and show that convergence in the Fell topology implies convergence in the modular Gromov-Hausdorff propinquity. [ABSTRACT FROM AUTHOR]

As the impact of climate change intensifies, meeting the energy demand of buildings in China's cold regions is becoming increasingly challenging, particularly in terms of cooling energy consumption. The effectiveness of integrating phase change material (PCM) into building envelopes for energy saving in China's cold regions is unclear. The aim of this study is to assess the effectiveness of PCM integration in building enclosures for energy efficiency in these regions. The research monitored and recorded indoor temperature data from typical residential cases from May to September. This measured data was then used to validate the accuracy of EnergyPlus22-1 software simulation models. Subsequently, the calibrated model was utilized to conduct a comparative analysis on the effects of PCM on indoor temperatures and cooling energy consumption across these regions. The results of these comparative analyses indicated that PCM can alleviate indoor overheating to varying degrees in severe cold regions of China. Focusing on north-facing bedrooms, applying PCMs reduced the duration of overheating in non-air-conditioned buildings in severe cold regions of China by 136 h (Yichun), 340 h (Harbin), 356 h (Shenyang), and 153 h (Dalian). In terms of cooling energy consumption, the energy saved by applying PCMs ranged from 1.48 to 13.83 kWh/m2. These results emphasize that the performance of PCM varies with climate change, with the most significant energy-saving effects observed in severe cold regions. In north-facing bedrooms in Harbin, the energy-saving rate was as high as 60.30%. Based on these results, the study offers guidance and recommendations for feasible passive energy-saving strategies for buildings in severe cold and cold regions of China in the face of climate change. Additionally, it provides practical guidance for applying PCMs in different climatic zones in China. [ABSTRACT FROM AUTHOR]