Search Results (84)

This study aims to explore the factors and mechanisms influencing the low-carbon development of Green Port Collection and Distribution Systems (GPCDSs) and to identify effective pathways and policy approaches to promote such development. Given the limited prior research integrating low-carbon policies, energy structure, and transportation systems, this study combines these three dimensions into a unified analytical framework. A scenario-based system dynamics model of GPCDS low-carbon development is established, incorporating factors such as low-carbon policies, energy structure, and transportation structure. The control variable method is employed to examine system behavior under 13 scenarios. The results indicate that freight subsidy policies and the internalization of carbon emission costs make the most substantial contributions to low-carbon development in GPCDS, yielding CO₂ emission reductions of 14.3% and 15.7%, respectively. Additionally, improvements in port railway infrastructure contribute to a 6.4% reduction in CO₂ emissions. In contrast, carbon taxes and energy structure adjustments have relatively limited effects, likely due to the delayed responsiveness of fossil fuel-dependent transportation sectors to pricing signals and the inherent inertia in transitioning energy systems. Full article

Wheel polygonal wear of metro deteriorates the vibration environment of the vehicle system, potentially leading to resonance-induced fatigue failure of components. This poses serious risks to operational safety and increases maintenance costs. To address the adverse effects of wheel polygonal wear, dynamic tracking tests and numerical simulations were conducted. The modal analysis focused on the vehicle–track coupling system, incorporating various track structures to explore the formation mechanisms and key influencing factors of polygonization. Test results revealed dominant polygonal wear patterns of the seventh to ninth order, inducing forced vibrations in the 50–70 Hz frequency range. These frequencies closely match the P2 resonance frequency generated by wheel–rail interaction. When vehicle–track coupling is considered, the track’s frequency response shows multiple peaks within this range, indicating susceptibility to resonance excitation. Additionally, rail joint irregularities act as geometric excitation sources that trigger polygonal development, while the P2 force resonance mode plays a critical role in its amplification. Full article

The microstructure and mechanical properties of foamed high-density polyethylene (HDPE) prepared with thermal expandable microspheres (TEMs) by an injection molding method were investigated, especially for the effect of different injection times, nozzle temperatures, and TEM contents. The results showed that it was beneficial to increase the expansion ratio in the HDPE of microspheres with a shorter injection time and higher nozzle temperature. However, the addition of TEMs reduced the crystallinity of the foamed HDPE, and the crystallinity decreases further with the increasing TEMs content, which led to the decrease in Young’s modulus and tensile strength. When the nozzle temperature reached 220 °C, the mechanical properties of the foamed HDPE diminished significantly due to the collapse of the internal cells. At the TEMs content of 1.5 wt.%, an injection time of 2.0 s, and a nozzle temperature of 210 °C, a foamed HDPE was prepared with a cell size of 89.72 μm and a cell density of 4.39 × 10⁸ cells/cm³. This foam exhibited a reduction density of 5.75%, a tensile strength of 22.6 MPa, and a Yang’s modulus of 1172.3 MPa, demonstrating excellent overall mechanical properties. Full article

Heterologous expression of the G231L variant of VioA into 16 strains of marine-derived Streptomyces, combined with bioactivity tracking, leads to the activation of seven antibiotic streptogramins (1–7) in Streptomyces sp. OUC20-O. Among these, compound 1, named linstreptogramin, is a new compound with an unusual linear streptogramin skeleton. The planar structure and stereochemistry of compound 1 were established based on extensive MS and NMR spectroscopic analyses, together with ECD calculations. In the antibacterial activity evaluation, compounds 1–4 showed significant growth inhibition against the multidrug-resistant Enterococcus faecium CCARM 5203 with MIC values of 0.2–1.6 µg/mL, which are comparable to the positive control vancomycin. Full article

Apple Valsa canker, caused by Valsa mali and Valsa pyri, is a devastating disease of apple trees and poses a severe threat to the sustainable development of apple production. Although the two species’ whole genomes have been sequenced, their mitochondrial genomes are still uncharacterized. In this study, the complete mitochondrial genomes of V. mali and V. pyri were assembled, annotated, and compared by bioinformatic methods. The results indicate that the mitogenomes are both circular DNA molecules with sizes of 213,406 bp and 128,022 bp, respectively. The AT skew values of the two Valsa species’ mitogenomes were positive, while the GC skew values were negative. Comparative mitogenome analysis revealed that the length and base composition of protein-coding genes (PCGs), rRNA genes, and tRNA genes differed between the two Valsa species. It was found that the expansion of V. mali was primarily attributable to the intronic regions. There are large numbers of interspersed repetitive sequences (IRS) in both Valsa mitogenomes; however, the proportion of IRS in V. mali (43.56%) was much higher than that in V. pyri (2.41%). The alignment of large fragments between the mitochondrial and nuclear genomes of both V. mali (1.73 kb) and V. pyri (5.17 kb) indicates that gene transfer between mitochondrial and nuclear genomes occurred during evolution. The ka/ks ratios for 15 core PCGs were below one, suggesting that these genes were subjected to purifying selection pressure. Comparative mitogenomics revealed that the two fungi had significant mitogenomic collinearity and large-scale gene rearrangements. The results of phylogenetic analysis based on Bayesian inference (BI) and maximum likelihood (ML) using a combined mitochondrial gene set confirmed that V. mali and V. pyri were fully independent taxa with a high bootstrap value of 100 (ML) and a high posterior probability of 1.0 (BI). This is the first report on the mitogenomes within the genus Valsa. These results will pave the way to understanding the evolution and differentiation of mitogenomes in the genus Valsa. Full article

Concrete coating technology is a key measure that enhances the durability of concrete structures. This paper systematically studies the performance, applicability, and impact of different types of anti-corrosion coatings on concrete durability, focusing on their resistance to chloride ion penetration, freeze–thaw cycles, carbonation, and sulfate corrosion. The applicability of existing testing methods and standard systems is also evaluated. This study shows that surface-film-forming coatings can create a dense barrier, reducing chloride ion diffusion coefficients by more than 50%, making them suitable for humid and high-chloride environments. Pore-sealing coatings fill capillary pores, improving the concrete’s impermeability and making them ideal for highly corrosive environments. Penetrating hydrophobic coatings form a water-repellent layer, reducing water absorption by over 75%, which is particularly beneficial for coastal and underwater concrete structures. Additionally, composite coating technology is becoming a key approach to addressing multi-environment adaptability challenges. Experimental results have indicated that combining penetrating hydrophobic coatings with surface-film-forming coatings can enhance concrete’s resistance to chloride ion penetration while ensuring weather resistance and wear resistance. However, this study also reveals that there are several challenges in the standardization, engineering application, and long-term performance assessment of coating technology. The lack of globally unified testing standards leads to difficulties in comparing the results obtained from different test methods, affecting the practical application of these coatings in engineering. Moreover, construction quality control and long-term service performance monitoring remain weak points in their use in engineering applications. Some engineering case studies indicate that coating failures are often related to an insufficient coating thickness, improper interface treatment, or lack of maintenance. To further improve the effectiveness and long-term durability of coatings, future research should focus on the following aspects: (1) developing intelligent coating materials with self-healing, high-temperature resistance, and chemical corrosion resistance capabilities; (2) optimizing multilayer composite coating system designs to enhance the synergistic protective capabilities of different coatings; and (3) promoting the creation of global concrete coating testing standards and establishing adaptability testing methods for various environments. This study provides theoretical support for the optimization and standardization of concrete coating technology, contributing to the durability and long-term service safety of infrastructure. Full article

Ni–Ti shape memory alloy (SMA) foams, capable of bringing revolutionary changes to crucial fields such as aerospace, energy engineering, and biomedical applications, are at the forefront of materials science research. With the aim of designing Ni–Ti SMA foams with complex structures, near-equiatomic Ni–Ti SMA foams featuring a rhombic dodecahedron (RD) structure were fabricated using selective laser melting (SLM) technology. Damping, superelasticity, and quasi-static compressive mechanical tests were carried out on the resultant foams. The findings indicated that the smaller the unit structure of the RD or the larger the rod diameter, the higher the damping and compressive strength of the foams would be. Foams with a cell structure of 2 mm × 2 mm × 2 mm and a rod diameter of 0.6 mm exhibited the highest damping, reaching up to 0.049, along with the highest compressive strength, reaching up to 145 MPa. Furthermore, if the specimen underwent solution and aging heat treatments, its strength could be further enhanced. Meanwhile, the specimens also exhibited excellent superelasticity; even when the pre-strain was 6%, the elastic recovery could still reach 97%. Based on microstructure characterization and finite element simulation, the property mechanisms and deformation rules of the foams were revealed. Full article

Breast cancer (BC) tops the list of causes for female fatalities globally, with the elusive triple-negative breast cancer (TNBC) constituting 10–20% of all cases. Current clinical strategies for combating TNBC encompass a multifaceted approach, including surgical intervention, radiation therapy, chemotherapy, and advanced targeted drugs and immunotherapies. While these modalities have catalyzed significant advancements in TNBC management, lingering limitations continue to pose formidable challenges. There is an acute need for novel therapeutics in the realm of TNBC treatment. Natural products (NPs) have emerged as a rich reservoir for pharmaceutical innovation, owing to their extraordinary range of structures and physicochemical properties. Scholars have reported diverse evidence of NPs’ efficacy against TNBC. This review aims to comprehensively explore the bioactive constituents, specifics and commonalities of chemical structure, and pharmacological mechanisms of NPs, specifically examining their multifaceted roles in impeding TNBC. NPs, which have recently garnered significant interest, are intriguing in terms of their capacity to combat TNBC through multifaceted mechanisms, including the suppression of tumor cell proliferation, the induction of apoptosis, and the inhibition of tumor metastasis. These natural agents primarily encompass a range of compounds, including terpenoids, glycosides, phenolic compounds, and alkaloids. An in-depth exploration has unveiled their involvement in key signaling pathways, including the transforming growth factor-beta (TGF-β), vascular endothelial growth factor A (VEGFA), phosphoinositide 3-kinase/protein kinase B (PI3K/AKT), Wingless/Int-1 (Wnt) /β-catenin, and mitogen-activated protein kinase (MAPK) pathways. Meanwhile, this review also looks at the challenges and opportunities that arise from harnessing natural compounds to influence TNBC, while outlining the prospective trajectory for future research in the field of NPs. Full article

A novel double-stranded RNA (dsRNA) virus was isolated and described from strain ZZZ210557 of plant endophyte Allocryptovalsa sichuanensis. The dsRNA virus contains four dsRNA segments, dsRNA1 to dsRNA4, with a size range of 3.8 to 5.1 kbp. Each possesses a single large ORF and is encapsulated in isometric particles approximately 42–47 nm in diameter. Notably, the dsRNA3 encoded sequence revealed modest similarities to the amino acid sequences of RdRps predicted from the nucleotide sequences of known and suspected members of the family Quadriviridae. Phylogenetic analysis of the putative RdRp with the corresponding proteins of other quadriviruses revealed that the dsRNA virus is a new member belonging to the family Quadriviridae, tentatively named Allocryptovalsa sichuanensis quadrivirus 1 (AsQV1). All four segments of AsQV1 could be successfully cured through ribavirin treatment, whereas it likely has no apparent impact on the morphologies or virulence of the host fungus. This study is the first report of a quadrivirus isolated from the fungus A. sichuanensis, and our results enhance the diversity of the quadrivirus. Full article

The strong uncertainty of the high proportion of new energy and the gradual decrease in the proportion of thermoelectric units have led to a shortage of system flexibility resources. System-level energy storage can efficiently alleviate the pressure of peak shaving and frequency regulation. Effective aggregation of flexibility resources is a key technical foundation for enhancing economic operation and advanced user-side response strategies of new power systems. However, the decentralization and heterogeneity of flexibility resources across generation, grid, load, and storage sides pose dual challenges of aggregation speed and accuracy. In view of this, this paper proposes a large-scale multi-dimensional flexibility polymerization method based on different response time scales. First, the flexibility resource definitions and response characteristics of generation, grid, load, and storage sides were analyzed and categorized according to their response time scales. Second, flexibility regulation models for resources on each side were established. On this basis, an improved Minkowski aggregation algorithm is proposed to precisely quantify the regulation capabilities of multi-dimensional flexibility resources at different time scales, enabling efficient resource aggregation. Finally, the results of the case analysis show that the proposed method can accurately aggregate the flexibility resource adjustment capabilities at different time scales to respond to the multi-time scale flexibility requirements of the system. Full article

The accelerating industrialization process of China expanded coal consumption and induced the depletion of resource reserves. Meanwhile, vast amounts of coal resources are “trapped” since they are located beneath buildings, railways, and water bodies, which is termed the “three-limitation” problem in China. In order to minimize the damage of coal extraction to two villages in Weibei Coalfield, China, a modified room-and-pillar method is integrated with backfilling. This work conducted a series of numerical tests in order to determine the optimal design of this integration in the Jinqiao coal mine, and field verification was carried out. The result shows that the widths of both the pillar and backfill body have an influence on the surface subsidence, but the subsidence is controlled to be within a low extent by the proposed method. Additionally, the backfill body becomes a stress concentration area, induced by the transmission of the weight of overlying strata from the gob area. Plastic failure is concentrated near the top of the backfill body and exhibits shear characteristics, while the immediate roof experiences less damage, primarily in the form of tensile failure. As the width of the backfill body decreases, the tensile and shear failures in the immediate roof gradually diminish, reducing the impact on the overlying strata. The protection of village buildings can therefore be guaranteed. Full article

Mental rotation is an important aspect of spatial ability. While the importance of measuring mental rotation has been explored, disputes still exist within the literature surrounding sources of item difficulty in mental rotation tests (MRTs). Furthermore, gender differences in MRT performance are often seen but not fully understood. In the current study, we analyzed sources of item difficulty in a set of spatial ability test items using the Linear Logistic Test Model (LLTM). We found that items with more cubes, color differences, and higher rotational complexity tend to be more difficult, whereas items that contain occlusion, a mirrored structure, and a homogenous configuration type tend to be easier. Next, using Differential Component Functioning (DCF) analysis, we analyzed gender differences across these different item characteristics, finding that the number of cubes and color characteristics made questions more difficult for males when compared to females. The results and implications of this study are discussed in further detail. Full article

Background: The increase in serving sizes of energy-dense nutrient-poor discretionary foods over time, with attractively presented large servings and package sizes, has led to portion distortion and a new ‘normal’ for serving sizes. Little data exists on the variations of portion size norms of discretionary foods across settings. This study aimed to examine the differences in the range of normal portion sizes of commonly consumed foods between home and out-of-home settings (coffee shops, restaurants). Methods: A repeated cross-sectional design was used, with nine selected discretionary foods and beverages included in a validated online image-series questionnaire. Participants completed the questionnaire at two time points to report their normal portion sizes in home and out-of-home settings. Quantile regression models were used to examine differences in the range of normal portion sizes (17th to 83rd percentile, representing the majority of the study population) between settings. Results: A final sample of 295 participants was included in the analysis (51% females, mean age 40 ± 14 years). The ranges of normal portion sizes did not differ by settings for all test foods except for sugar-sweetened beverages (SSB) tested in both containers and glassware. SSB showed smaller normal portion sizes at home compared to fast food restaurants (in a bottle/can and in a glass/cup; p < 0.001). Conclusions: These findings suggest that the portion size norms of many discretionary foods are mostly consistent in home and out-of-home settings. As the typical serving sizes available to consumers in the out-of-home settings are large, it is essential to establish practical serving size guidelines directed at the food industry to increase the availability of smaller size options and empower consumers towards better portion control. Full article

Bio-oil as a substitute or modifier for petroleum asphalt has significant environmental, economic, and sustainable development implications. However, the insufficient high-temperature and anti-aging characteristics of bio-asphalt lead to the limited application of bio-oil in road engineering. In this study, the characteristics of bio-asphalt were reinforced by nano-Al₂O₃ and nano-SiO₂. The nanomaterial-modified bio-asphalt was evaluated using basic characteristics, viscosity, and high- and low-temperature rheological characteristic tests. Meanwhile, the road behavior of nanomaterial-modified bio-asphalt mixtures was assessed. The test results demonstrated that incorporating bio-oil improved the low-temperature performance of PA. Compared with PA, BA’s ductility was increased by 83.87%. Nano-Al₂O₃ and nano-SiO₂ positively affected the bio-asphalt’s temperature sensitivity and high-temperature and anti-aging characteristics but inhibited the low-temperature characteristics. Combining the results of the high- and low-temperature characteristics of nanomaterial-modified bio-asphalt, a nano-Al₂O₃ dosage between 4 and 6% or a nano-SiO₂ dosage between 6 and 8% can realize the enhancement of high-temperature and anti-aging characteristics of bio-asphalt, and the low-temperature characteristics are better than those of petroleum asphalt. Meanwhile, the dynamic stability, crack resistance, and water loss resistance of the nanomaterial-modified bio-asphalt mixtures meet the specification requirements. The adjustable and designable high- and low-temperature characteristics of bio-asphalt can be realized by adjusting the dosage of nanomaterials. The application of bio-oil and nanomaterials promotes the resourceful utilization of waste and provides new possibilities for road engineering materials. Full article

Single-season rice describes the area under rice cultivation from May–October of the year. Many scholars have used lower-resolution data to study single-season rice in different regions, but using high-precision and high-resolution single-season rice data can reveal new phenomena. This paper uses a long-time-series, high-precision, and high-resolution single-season rice cultivation dataset to conduct an in-depth analysis of the spatial–temporal variability characteristics of single-season rice in Jiangsu Province, China, from 2017 to 2021. It explores the correlation between meteorological factors and greenhouse gasses for single-season rice. It analyzes the driving role of social factors on single-season rice. The results showed that single-season rice was mainly grown in the central and northeastern regions of the study area. The single-season rice cultivation was significantly reduced in 2020 due to the impact of COVID-19. Single-season rice strongly correlates with meteorological factors in time but shows a weak spatial correlation. This is because human factors largely dominate the area under single-season rice cultivation. Methane emissions in the study area are mainly influenced by anthropogenic activities rather than single-season rice. Social factors are essential in controlling single-season rice cultivation in the study area. This study was conducted in Jiangsu Province, China. Still, the methodology and results have important implications for agricultural production and environmental management studies in other regions, and some findings have general applicability. Full article