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In this study, Ce2[Zr1−x(Ba1/3Nb2/3)x]3(MoO4)9 (0.02 ≤ x ≤ 0.1, CZ1−xNx) ceramics were sintered at 600 °C and 700 °C using the traditional solid-state method. An analysis conducted through XRD and Rietveld refinement confirmed that all the CZ1−xNx ceramics displayed a single phase with a trigonal structure (space group R-3c). The observed increases in cell volume with increasing x values indicate the successful substitution of (Ba1/3Nb2/3)4+. The high densification of the synthesized phase was validated by the density and SEM results. Additionally, the P-V-L theory demonstrates a strong correlation between the Ce-O bond and εr, as well as τf, and between the Mo-O bond and Q×f. Notably, the CZ0.98N0.02 ceramics demonstrated superior performance at 675 °C, exhibiting εr = 10.41, Q×f = 53,296 GHz, and τf = −23.45 ppm/°C. Finally, leveraging CZ0.98N0.02 ceramics as substrate materials enabled the design of a patch antenna suitable for the 5G communication band, demonstrating its significant potential in this field.

Objectives: Excessive reactive oxygen species (ROS) in diabetic wounds are major contributors to chronic wounds and impaired healing, posing significant challenges in regenerative medicine. Developing innovative drug delivery systems is crucial to address these issues by modifying the adverse microenvironment and promoting effective wound healing. Methods: Herein, we designed a novel drug delivery platform using manganese dioxide nanoflower hybridized gold nanoparticle composites (MnO2-Au) synthesized via a hydrothermal reaction, and investigated the potential of MnO2-Au nanoflowers to relieve the high oxidative stress microenvironment and regulate diabetic wound tissue healing. Results: This hybrid material demonstrated superior catalytic activity compared to MnO2 alone, enabling the rapid decomposition of hydrogen peroxide and a substantial reduction in ROS levels within dermal fibroblasts. The MnO2-Au nanoflowers also facilitated enhanced dermal fibroblast migration and Col-I expression, which are critical for tissue regeneration. Additionally, a hydrogel-based wound dressing incorporating MnO2-Au nanoflowers was developed, showing its potential as an intelligent drug delivery system. This dressing significantly reduced oxidative stress, accelerated wound closure, and improved the quality of neonatal epithelial tissue regeneration in a diabetic rat skin defect model. Conclusions: Our findings underscore the potential of MnO2-Au nanoflower-based drug delivery systems as a promising therapeutic approach for chronic wound healing, particularly in regenerative medicine.

This study investigated the influence of green manure planting on the spectroscopic properties of dissolved organic matter (DOM) in saline–alkali soil under freshwater leaching conditions at different soil depths. The UV254, UV253/UV203, α300, α355, SUVA254, SUVA260, and SR ultraviolet parameters indicated reductions in the content of large molecular substances, benzene ring substitution degree, colored dissolved organic matter, aromaticity, and hydrophobic components in the soil leachate DOM with an increasing soil depth. Compared with the non-green manure treatment control, green manure planting mitigated the leaching of dissolved organic matter in soil during saline irrigation, with rape green manure demonstrating superior effectiveness. Utilizing three-dimensional fluorescence combined with parallel factor analysis, this study analyzed three fluorescent components of soil leachate DOM: C1 (visible-light fulvic acid), C2 (humic acid), and C3 (tyrosine-like protein). The combined contribution of the two humic substance components (C1 + C2) was approximately 70%, indicating the dominance of humic substances in leachate DOM. The fluorescence parameters of soil leachate DOM included an average of the fluorescence index (FI) values between 1.4 and 1.9, low humification index (HIX) values consistently below 4, and biological index (BIX) values ranging from 0.8 to 1.0, suggesting a mixed source, low humification degree, poor stability, and moderate self-source characteristics. Compared with the non-green manure treatment control, both the green manure treatments exhibited a relatively higher proportion of biogenic sources and humification degree in soil leachate DOM. This suggests that planting green manure can reduce the relative DOM content under freshwater leaching conditions, increase the proportion of biogenic sources in soil leachate DOM, and enhance soil humification. Planting rapeseed green manure can diminish the leaching of DOM from land sources and augment soil humification.

Grasping the interrelationship between the supply and demand of ecosystem services (ESs) and spatial scale characteristics is the foundation for effective ecological zoning management, which helps to realize a win–win situation for both ecological protection and economic development. This paper focuses on the following three real problems: mismatch in ES supply and demand evaluation, mechanical and subjective delineation of ecological zoning, and rough management strategies, and constructs a multi-scale ecological zoning management framework for the “comprehensive evaluation of supply and demand, ecological zoning, and enhancement of human well-being”. This study integrates the InVEST model, SOM, Z-score quadrant matching, and coordination degree method, and applies them to the ecological management zoning of Hangzhou. The results show that (1) the spatial differentiation of ESs in Hangzhou is significant. The spatial pattern of the five types of ES supply varies at the county scale and the grid scale on which ES demand is concentrated and is consistent at different scales. (2) ES supply–demand matching in Hangzhou is at the basic coordination and can be divided into four modes including HH, LH, LL, and HL at both the county and grid scales. On the small scale, the proportion of mismatches declines slightly, but the severity rises. (3) ES supply is divided into four categories as follows: the food production bundle, the carbon storage bundle, the ESs balancing bundle, and the ESs depleting bundle, and clarifies the priority of ES management. (4) Construct an ecological management practice path, delineates 6 ecological management zones at the county scale and 19 secondary management zones at the grid scale. Targeted measures are proposed in terms of supply–demand adjustment strategies, ecological management strategies, and key implementation areas. This study helps to incorporate the interaction between the supply and demand of ESs into the planning framework and provides decision-making support for refined ecological management.

The maturity degree of organic fertilizer affects its application effect, but this application effect difference and the underlying reasons for it remain largely unclear. This study explored the effects of cattle manure compost with different maturities on soybean yield, soil physicochemical properties, and biological properties, and the underlying reasons for the differences in the application effects of organic fertilizers with different maturities. The results showed that the T21d treatment (GI = 62.5%, germination index) had the optimal effect on increasing soybean yield, and its effect on improving basic soil physicochemical properties, active organic matter components, enzyme activity, and microbial diversity was the most obvious. Compared with the control (CK), the soybean yield was increased by 15.1% under T21d treatment, and the soil organic matter (OM), alkali-hydrolyzed nitrogen (AN), available phosphorus (AP), and available potassium (AK) contents were increased by 29.9%, 25.0%, 22.2%, and 8.4%, respectively; the dissolved organic matter (DOM), extractable humus (HE), humic acid (HA), and fulvic acid (FA) contents in the soil were increased by 96.5%, 22.6%, 16.7%, and 30.6%, respectively; and the activities of soil phosphatase, neutral protease, urease, and cellulase were increased by 45.4%, 164.1%, 33.9%, and 128.9%, respectively. However, the fertilizer efficiency under the T28d, T45d, and T60d treatments with high-maturity organic fertilizers was lower than that under T21d. In general, the appropriate maturity of organic fertilizers has a positive effect on soil improvement and yield increase, but the excessive maturity of organic fertilizers reduces their application effects.

Balancing peptidoglycan (PG) synthesis and degradation with precision is essential for bacterial growth, yet our comprehension of this intricate process remains limited. The NlpI-Prc proteolytic complex plays a crucial but poorly understood role in the regulation of multiple enzymes involved in PG metabolism. In this paper, through fluorescent D-amino acid 7-hydroxycoumarincarbonylamino-D-alanine (HADA) labeling and immunolabeling assays, we have demonstrated that the NlpI-Prc complex regulates the activity of PG transpeptidases and subcellular localization of PBP3 under certain growth conditions. PBP7 (a PG hydrolase) and MltD (a lytic transglycosylase) were confirmed to be negatively regulated by the NlpI-Prc complex by an in vivo degradation assay. The endopeptidases, MepS, MepM, and MepH, have consistently been demonstrated as redundantly essential “space makers” for nascent PG insertion. However, we observed that the absence of NlpI-Prc complex can alleviate the lethality of the mepS mepM mepH mutant. A function of PG lytic transglycosylases MltA and MltD as “space makers” was proposed through multiple gene deletions. These findings unveil novel roles for NlpI-Prc in the regulation of both PG synthesis and degradation, shedding light on the previously undiscovered function of lytic transglycosylases as “space makers” in PG expansion.

Territorial ecological restoration (TER) is a critical step for promoting the development of an ecological civilization, as well as a significant strategic task relating to national ecological security and the well-being of a population. However, calculating the ecological restoration potential (ERP) is a key challenge in TER. Using Zhaoping County as an example, this study calculated the ecological restoration natural potential (ERNP), including the vegetation coverage potential, water conservation potential, windbreak and sand fixation potential, and biodiversity potential, and proposed an ERP calculation method based on the correction of ERNP with an ecological security pattern (ESP) and social support (SS). The findings revealed several key points. First, using the similarity habitat method to calculate ERNP highlighted significant disparities in the vegetation coverage, water conservation, windbreak and sand fixation, and biodiversity across Zhaoping County. These variations were contrary to regional ecological service functions. Second, overall, the ESP levels in Zhaoping County were high, accounting for about 60.42% of its total area being classified as high or relatively high level, with the towns exhibiting strong SS abilities primarily located in the northern region. Third, the ERP results which are between 0 and 1 indicated that areas with higher potential were mainly found in the west and northeast of Zhaoping, while lower potential areas were concentrated in the northwest and south; of them, the ERP index value in most regions is between 0.2 and 0.3, accounting for about 43.97% of the area. Finally, suggestions for the TER project layout and measures to enhance the ERP were proposed based on these ERP calculations. This study offers new insights into ERP strategies while providing guidance for identifying critical areas requiring restoration.

Land use change detection (LUCD) is a critical technology with applications in various fields, including forest disturbance, cropland changes, and urban expansion. However, the current review articles on LUCD tend to be limited in scope, rendering a comprehensive review challenging due to the vast number of publications. This paper systematically reviewed 3512 articles retrieved from the Web of Science Core database between 1985 and 2022, utilizing a combination of bibliometric analysis and machine learning methods with LUCD as the main focus. The results indicated an exponential increase in the number of LUCD studies, indicating continued growth in this research field. Commonly used methods include classification-based, threshold-based, model-based, and deep learning-based change detection, with research themes encompassing forest logging and vegetation succession, urban landscape dynamics, and biodiversity conservation and management. To build an intelligent change detection system, researchers need to develop a flexible framework that integrates data preprocessing, feature extraction, land use type interpretation, and accuracy evaluation, given the continuous evolution and application of remote sensing data, deep learning, big data, and artificial intelligence.

Soil organic matter (SOM) is an important component of soil and plays an important role in improving the soil’s physical and chemical properties. Ascertaining the spatial distribution of soil organic matter and its main controlling factors in the context of provincial scale farming is of important guiding significance for soil carbon sequestration, emission reduction and sustainable utilization. Using 257 soil profiles from the second soil survey in Shandong Province, GIS, we applied geostatistical methods to study the spatial distribution characteristics of SOM in topsoil. In addition, correlation and regression analyses were used to explore the main controlling factors over the spatial variation of SOM. The results showed that the mean amount of SOM in Shandong province ranged from 1.20–74.90 g·kg−1, with a coefficient of variation of 73.52%, which is a medium level of variation. The distribution of SOM in the study area was patchy, with higher levels of organic matter in the central, eastern, and northern parts, and lower levels of organic matter in the south-west. The comprehensive explanatory ability of all factors reached 52.30%. Soil type and parent material were the main controlling factors for the spatial variability of SOM in the Shandong Province, followed by soil texture and land use type, with topography and climatic factors having relatively little influence.

Metal magnetic memory testing (MMMT) is a nondestructive testing technique that can detect early signs of damage in components. Many scholars have studied the effect of uniaxial stress on the self-magnetic-leakage field (SMLF)’s strength. Nevertheless, there is still insufficient research on the combined action of bending and shear. We studied the law of distribution of the magnetic signal, ΔHSF(y), at different stress parts of a steel box girder and the quantitative relationship between the magnetic characteristic parameters and the external load. The results showed that the MMMT could accurately detect the early stress concentration zone (SCZ) and predict the final buckling zone of steel box girders. It could be judged that the corresponding parts of the steel box girder had entered the elastic-plastic working stage by the reverse change of the ΔHSF(y)-F and |HSF(y)|a -F curve trends, this feature could be used as an early warning sign before the steel box girder was deformed or destroyed. The fitted |HSF(y)|ave -F linear expression could be used as the expression between the magnetic signal and the shear capacity. All the evaluation methods were expected to provide a basis for effectively evaluating the stress state of steel box girders with the MMMT method.

The lead–zinc ore is a typical low-grade complex polymetallic sulphide ore. Its typical mineralogy is characterized by a high content of cryptocrystalline graphite, low content of lead, zinc, and copper, and fine grain size. However, the aggregation size of sulfide mineral aggregations is coarse, and the symbiotic relationship is relatively simple. Conventional process treatment requires the fine grinding of ore into mineral monomer dissociations followed by preferential flotation, but this method has a poor sorting index and high production cost. In this paper, the grain size of the sulfide mineral aggregates determined by mineralogical studies is used to determine the fineness of the grinding, so that the liberation degree of the sulfide ore in the coarse grinding product reaches 70%, and each flotation process is used to collect rough concentrate. In the first step of flotation, the carbon in lead–zinc sulfide ore was removed by adding #2 oil to the flotation tank at a dosage of 40 g/t. In the second flotation process, the pH was adjusted to 7.2, the dosage of isopropyl xanthate was 20 g/t, the dosage of #2 oil was 30 g/t; the flotation reagent in the third step was isopropyl xanthate, and the dosage was 7.5 g/t, with a #2 oil of 15 g/t. Each flotation process concentrate is collected. Finally, the grades of lead and zinc in the final concentrate were 1.6% and 5.71%, respectively. In addition, the recoveries of lead and zinc were 91.78% and 92.07%, respectively. The yield of tailings was 50.6%. By the flotation of sulfide aggregates, a large number of gangues are avoided to participate in fine grinding, which helps to reduce the energy consumption of the mill.

Soil organic matter (SOM) plays a crucial role in promoting soil tillage, improving soil fertility and providing crop nutrients. Investigation and sampling are the premise and basis for understanding the spatial distribution of SOM. The number of sampling points will affect the accuracy of spatial variation of SOM. Therefore, it is important scientific work to determine a reasonable number of sampling points under the premise of ensuring accuracy. In this study, Kenli County, a typical area of the Yellow River Delta in China, was taken as an example to investigate the effect of different sampling points on spatial-variation expression of SOM. A total of 12 sample subsets (including 900 samples) were randomly sampled at equal intervals from the 900 sample points, using geographic information system (GIS) technology and geostatistical analyses to explore the optimal number of samples. The results showed that the SOM content in the study area had a lower-middle degree of variation. As the number of sample points decreased, the spatial distribution of SOM showed the gradual weakening of detail-characterization ability; and when the number of sample points was too small (2. The research results could provide important references for investigation of SOM content in areas with similar natural geographical conditions.

Many studies have confirmed the important roles of nutritional status and micronutrients in the COVID-19 pandemic. Magnesium is a vital essential trace element that is involved in oxidative stress, inflammation, and many other immunological functions and has been shown to be associated with the outcome of COVID-19 infection. Here, we conducted a nationwide retrospective cohort study in the United States involving 1150 counties, 287,326,503 individuals, and 5,401,483 COVID-19 confirmed cases as of 30 September 2020 to reveal the infection risk of the populations distributed in low-magnesium areas in the early transmission of COVID-19. Our results indicate that the average county-level COVID-19 cumulative incidence in low-magnesium areas was significantly higher than in the control areas. Additionally, a significant negative nonlinear association was found between environmental magnesium concentration and the county-level COVID-19 cumulative incidence. Furthermore, the populations distributed in low environmental magnesium areas faced a higher COVID-19 infection risk (RR: 1.066; CI: 1.063–1.068), among which females (RR: 1.07; CI: 1.067–1.073), the 0–17 years subgroup (RR: 1.125; CI: 1.117–1.134), the 65+ years subgroup (RR: 1.093; CI: 1.087–1.098), black people (RR: 1.975; CI: 1.963–1.986), populations outside metro areas, and counties with a smaller population experienced higher risk of infection by COVID-19 than other subgroups. Considering that the magnesium intake of about half the population of the United States is below the daily required dose, our study will contribute to the creation of long-term public health strategies to help protect against COVID-19.

The mineral composition of copper–cobalt ores is more complex than that of copper sulfides, and it is also difficult to discard tailing efficiently in primary flotation for the fine-grained disseminated of ore. In this work, a mineral liberation analyzer (MLA) was employed to study the characteristics of minerals. As a significant mineralogical characteristic, the liberation degree of useful mineral aggregates was determined after grinding, and a correlation was established between the ore grinding size and mineralogical characteristics. The results showed that the adopted ore occurred in sulfide form. However, the particle size of the mineral’s monomer was fine grained, whereas its aggregate was coarse. The sulfide mineral aggregate obtained after primary grinding was selected as the recovery object, and its mineralogical characteristics, such as liberation degree and particle size, were investigated to promote total recovery in primary flotation. The copper–cobalt sulfide concentration was obtained at the following optimal conditions: the grinding size of −0.074 mm (65%), the aggregate’s liberation degree of 67%, a collector dosage of 50 g·t−1, a collector combination of 35% aerofloat + 65% butyl xanthate, a pH of 8.5, and 2# oil (a terpineol type foaming agent) dosage of 60 g·t−1. The recovered rough Cu and Co concentrates were 89.45% and 88.03%, respectively. Moreover, the grades of Cu and Co were 13.4% and 4.81%, respectively, with 85.07% of the ore weight discarded as tailing. The consideration of sulfide aggregates instead of singeral minerals mineralogy characters in primary grinding and primary flotation provides an effective theoretical guide for the sorting of sulfide minerals and reduction in the power consumption of grinding.

Intelligent detection and recognition of ships from high-resolution remote sensing images is an extraordinarily useful task in civil and military reconnaissance. It is difficult to detect ships with high precision because various disturbances are present in the sea such as clouds, mist, islands, coastlines, ripples, and so on. To solve this problem, we propose a novel ship detection network based on multi-layer convolutional feature fusion (CFF-SDN). Our ship detection network consists of three parts. Firstly, the convolutional feature extraction network is used to extract ship features of different levels. Residual connection is introduced so that the model can be designed very deeply, and it is easy to train and converge. Secondly, the proposed network fuses fine-grained features from shallow layers with semantic features from deep layers, which is beneficial for detecting ship targets with different sizes. At the same time, it is helpful to improve the localization accuracy and detection accuracy of small objects. Finally, multiple fused feature maps are used for classification and regression, which can adapt to ships of multiple scales. Since the CFF-SDN model uses a pruning strategy, the detection speed is greatly improved. In the experiment, we create a dataset for ship detection in remote sensing images (DSDR), including actual satellite images from Google Earth and aerial images from electro-optical pod. The DSDR dataset contains not only visible light images, but also infrared images. To improve the robustness to various sea scenes, images under different scales, perspectives and illumination are obtained through data augmentation or affine transformation methods. To reduce the influence of atmospheric absorption and scattering, a dark channel prior is adopted to solve atmospheric correction on the sea scenes. Moreover, soft non-maximum suppression (NMS) is introduced to increase the recall rate for densely arranged ships. In addition, better detection performance is observed in comparison with the existing models in terms of precision rate and recall rate. The experimental results show that the proposed detection model can achieve the superior performance of ship detection in optical remote sensing image.

The sodium leaching ratio (ηN) of ferric bauxite direct reduction process is much lower than that of ordinary bauxite; thus, the former consumes more sodium than the latter. ηN can be promoted by increasing the dosage of sodium or restricted by increasing the heating temperature and time. However, the restriction effect of heating temperature is 16.67 times larger than that of heating time, and the restriction effect decreases 47.03 times faster when heating temperature increases than that process of heating time. These imply that ηN improves with the increasing sodium carbonate dosage and the decreasing heating temperature.

Direct reduction is an emerging utilization technology of ferric bauxite. However, it requires much more sodium carbonate than ordinary bauxite does. The volatilization is one of the most significant parts of sodium carbonate consumption, as reported in previous studies. Based on the new direct reduction method for utilization of ferric bauxite, this paper has systematically investigated factors including heating temperature, heating time, and sodium carbonate dosage influencing sodium volatilization. For the purpose of reducing sodium volatilization, the Box–Benhken design was employed, and the possibility of separating iron and sodium after direct reduction was also investigated.