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ABSTRACT High-standard farmland construction is an important process that can enhance food security and accelerate new-style modernization agriculture. Hyperspectral remote sensing can provide data and technical support for this type of construction to provide a reference when optimizing high-standard farmland construction areas. This study was performed in Xinzheng City, the primary grain-producing areas in Henan Province. Field sampling and indoor hyperspectral spectroscopy (350~2500 nm) were combined; spectral transformations such as continuum removal (CR) were performed after Savitzky‒Golay (SG) convolution smoothing; and the best hyperspectral bands were selected as the common index of the soil properties by correlation analysis and fuzzy clustering maximum tree. A hyperspectral inversion model was built for the panel data model of the fixed effect variable coefficient based on the ordinary least squares estimation method (OLS), including panel data describing pH, organic matter, nitrogen, phosphorus, potassium, iron, chromium, cadmium, zinc, copper, and lead of 116 samples in Xinzheng City. Results show that the panel data model is of good quality overall, and the goodness of fit is higher (R2 = 0.9991, F = 2195.67). The precision test results indicate that the models performed well at both description and prediction, including accurate quantification, with an RPD above 2.5. Thus, the proposed model provides an important basis for soil information management, resource evaluation, and a reference when optimizing high-standard farmland construction processes.

With the development of new energy, energy storage, and flexible DC technology, AC/DC hybrid distribution networks have gradually become an important development direction for future distribution networks. The access of a large number of power electronic devices has brought dynamic problems such as low frequency oscillations to the distribution network. In order to deeply study the low frequency oscillation problem on the DC side of AC/DC distribution networks, detailed modeling of key links is conducted such as H-bridge series and isolated bidirectional active bridge structures, three-phase inverters, and three-phase Buck converters in the main valve tower of power electronic transformer. Through time domain simulation, the 4 Hz low frequency oscillation phenomenon on the DC side of the AC/DC distribution network in the actual project is reproduced, and the correctness of the established mathematical model is verified. Based on the established mathematical model, qualitative analysis is conducted on key influencing factors such as power and controller parameters, and the final conclusions are as follows: power level and Buck link voltage loop control parameters affect system stability, the integral coefficient of the current loop in the Buck link affects the oscillation frequency.

Cultivated land is the foundation of food security, while coal guarantees the security of the energy. The coal-cropland overlapped area accounts for approximate 42.7% of the total cultivated land area in China, making it become a prominent contradiction between the extensive mining and cultivated land protection. How to realize the coordinated development of the coal mining and the cultivated land protection is an urgent problem in coal-cropland overlapped areas. This paper analyzes the research status and existing issues of the coordinated development between mining and cultivated land protection from the following three aspects: the damage mechanism of subsidence land in plain coal-cropland overlapped areas, the damage degree evaluation of subsidence land induced by mining, the control technology for the mining subsidence. Then, considering the characteristics of the cultivated land, such as the extensive protection-needed area and the high deformation tolerance, a new technical approach of controlling regional rock strata and surface deformation in green mining is proposed by combining source control and restoration. The corresponding prediction and control design methods of surface deformation are established. Additionally, the key research directions for the coordination of coal mining and cultivated land protection in the plain coal-cropland overlapped areas are pointed out, including the driving mechanism of cultivated land damage induced by mining in the plain area, protection thresholds for the quality of the cultivated land in subsidence areas, theories and methods of the subsidence coordinated control of the green mining facing the cultivated land protection. The main objective of this paper is to promote the coordinated development of the green mining and the cultivated land protection in the plain coal-cropland overlapped areas.

Near‐infrared photosensitizers are valuable tools to improve treatment depth in photodynamic therapy (PDT). However, their low singlet oxygen (1O2) generation ability, indicated by low 1O2 quantum yield, presents a formidable challenge for PDT. To overcome this challenge, the heptamethine cyanine was decorated with biocompatible S (Scy7) and Se (Secy7) atom. We observe that Secy7 exhibits a redshift in the main absorption to ~840 nm and an ultra‐efficient 1O2 generation capacity. The emergence of a strong intramolecular charge transfer effect between the Se atom and polymethine chain considerably narrows the energy gap (0.51 eV), and the heavy atom effect of Se strengthens spin–orbit coupling (1.44 cm−1), both of which greatly improved the high triplet state yield (61 %), a state that determines the energy transfer to O2. Therefore, Secy7 demonstrated excellent 1O2 generation capacity, which is ~24.5‐fold that of indocyanine green, ~8.2‐fold that of IR780, and ~1.3‐fold that of methylene blue under low‐power‐density 850 nm irradiation (5 mW cm−2). Secy7 exhibits considerable phototoxicity toward cancer cells buried under 12 mm of tissue. Nanoparticles formed by encapsulating Secy7 within amphiphilic polymers and lecithin, demonstrated promising antitumor and anti‐pulmonary metastatic effects, exhibiting remarkable potential for advancing PDT in deep tissues. [ABSTRACT FROM AUTHOR]

AbstractSpatial community detection plays a crucial role in the analysis of spatially embedded networks. However, most existing methods adopt modularity as an objective function, which may fail to detect small spatial communities (i.e. the well-known resolution-limit problem). To alleviate this problem, a local network structure-based spatially constrained Leiden method was developed. First, the weights of the edges were reset based on the local network structure, which facilitated a clearer delineation between distinct communities. Second, we extended Leiden, an effective community detection method, to spatial community detection content by adding spatial constraints. Experiments on simulated datasets demonstrated that the proposed method is superior to four state-of-the-art methods for detecting spatial communities of different sizes. A case study conducted using the Shenzhen taxi dataset demonstrated that the proposed method outperformed four state-of-the-art methods in revealing urban spatial structures. Notably, the modularity of the spatial communities detected using the proposed method exhibited a marked improvement, nearly doubling that of the four comparative methods in the case study. This study presents a novel and promising framework for detecting spatial communities using modularity. [ABSTRACT FROM AUTHOR]

In this study, five drying methods (hot air drying [HD], light wave drying [LD], far infrared drying [FID], freeze drying [FD], and heat pump drying [HPD]) were applied to dry Sargassum fusiforme. The color, rehydration rate (RR), and volatile flavor substances of dried S. fusiforme were compared and analyzed, and the content, molecular weight (Mw), monosaccharide composition, and antioxidant activity of dried S. fusiforme crude polysaccharides (SFCPs) were analyzed. The results showed that S. fusiforme dried by different drying methods showed different colors. FD produced S. fusiforme with better RR (p < 0.05). The Mw of the SFCPs were 624.06, 534.86, 683.00, 1077.13, and 981.91 kDa, respectively, for HD, LD, FID, FD, and HPD. The Mw and DPPH (1,1‐diphenyl‐2‐picrylhydrazyl) radical scavenging rates of SFCP‐FD were greater than those of the remaining four drying methods; however, the ABTS (2,2 ′‐azobis‐3‐ethylbenzothiazoline‐6‐sulfonic acid) and OH (hydroxyl) radical scavenging rates were highest in the SFCP‐HPD. GC‐IMS analysis showed that the drying method affected the content and composition of volatile flavor compounds. Principal component analysis (PCA) analysis indicated that the flavors of dried S. fusiforme were quite different from that of fresh S. fusiforme, and the flavors of HD, LD, and FID were similar, while the flavors of FD and HPD were similar. [ABSTRACT FROM AUTHOR]

Given the increasing frequency and severity of floods caused by climate change, there is a pressing requirement for creative ways to improve public comprehension and control of hydrological phenomena. Contemporary technology provides unparalleled possibilities to transform this domain. This project investigates the possibilities for merging gaming engines and digital twins to enhance flood education, data visualization, and interactive monitoring. This study proposes the utilization of immersive digital twins to enhance the comprehension of hydrological and hydraulic systems. The suggested method utilizes game engines to generate dynamic and interactive models that connect raw data to practical insights, enabling a more profound understanding of flood dynamics. This study underscores the wide-ranging usefulness of digital twins in various watersheds by focusing on the development of advanced monitoring systems, the benefits of improved data visualization, and educational outreach. The incorporation of real-time data via IoT technology considerably improves the significance and precision of these virtual models. This novel approach seeks to refashion flood management approaches by cultivating well-informed stakeholders and advocating for effective environmental education, ultimately leading to more resilient and prepared communities. An immersive digital twin of the real world can assist decision-makers technically, psychologically, and mentally by making complex phenomena easier to understand and visualize, thanks to real-time data and simulations that keep the information up-to-date, consequently leading to a more precise and intuitive decision-making process. [ABSTRACT FROM AUTHOR]

In this study, polyurethane (PU) hydrogels were synthesized via mercapto curing reaction to elucidate the effect of molecular interactions between isocyanate and soft segments on the properties of hydrogels. Further, the mesh size, mechanical properties, hydrophilicity, and biological properties of the PU hydrogels were determined. In the isocyanate series, the structural regularity and rigidity of 4,4′‐dicyclohexylmethane diisocyanate (HMDI) favored the formation of hydrogel materials with small mesh size, high modulus, and low water absorption. In contrast, l‐lysine diisocyanate (LDI) favored the materials with large mesh size, low modulus, and good hydrophilicity. In the soft‐segment series, the strong hydrogen bonds of polycarbonate diol (PCDL) favored the formation of materials with small mesh size, dense cross‐link points, and high modulus, whereas weak hydrogen bonds of polytetrahydrofuran ether glycol (PTMG) favored the hydrogel materials with small mesh size, few crosslink points, and low modulus. PU hydrogels exhibit excellent cytocompatibility, anti‐cell adhesion, and anti‐inflammatory properties. Therefore, this study offers valuable insights into understanding the chain structure and macroscopic properties, thus contributing to preparing PU hydrogels with varying performances, as desired. [ABSTRACT FROM AUTHOR]