Search Results (80)

Metasurfaces have drawn extensive research attention for their unique optical properties and vast application potential. Among the various resonant modes induced in metasurfaces, BIC and electric anapole modes stand out as particularly interesting due to their distinctive physical characteristics. In this work, we designed and investigated novel dimeric dumbbell-shaped metasurfaces incorporating two independently tunable asymmetric parameters. This structural innovation enables the simultaneous excitation of both electric anapole and QBIC modes under normally incident MIR illumination. More importantly, by adjusting these two asymmetric parameters, one can independently tune the resonance peaks of the two modes, thereby overcoming the performance limits of conventional single-peak modulation. This metasurface design demonstrates outstanding performance for dielectric environment-sensing applications. We conducted a comprehensive investigation of the sensing sensitivity for dumbbell-shaped metasurfaces of various geometries. Our simulation results show that the circular-shaped configuration achieved high sensitivity, reaching 20,930 GHz/RIU. This work offers a novel design paradigm for multi-mode control and functionalization of metasurface structures. Full article

A slanted axial-flow pump is extensively applied in coastal pumping stations; however, severe bias flow within the outlet passage will result in unstable operation and low efficiency of the slanted axial flow pump system. In order to mitigate bias flow in a slanted axial-flow pump outlet passage, seven exit setting angle schemes of the guide vanes were designed. The influence mechanisms of the guide vane exit setting angle on internal flow characteristics, hydraulic loss, flow deviation coefficient, vortex evolution patterns, and pump system efficiency were systematically investigated. The results demonstrate that under design flow conditions, as the exit setting angle of the guide vane ranges from 90° to 105°, the flow field in the first half of the guide vane remains essentially the same. The low-velocity region at the guide vane outlet demonstrates initial contraction followed by gradual expansion with increasing stagger angles. Looking downstream within the flow passage from the left to the right, the hydraulic loss in the outlet passage goes up after an initial descending trend as the exit setting angle increases. When the exit setting angle is 97.5°, the bias coefficient of the outlet passage is 1.031. At this point, the vortex core distribution intensity within the outlet passage reaches a minimum, corresponding to the lowest recorded hydraulic loss of 0.230 m. Compared with the original guide vane scheme, the scheme with an angle set at 97.5° can improve the pump system efficiency of the slanted axial flow pump system, whether the flow is set at a design point or at a large point, and the pump system efficiency is increased by 2.3% under design flow conditions. Full article

When large-scale and clustered distributed photovoltaic devices are connected to an active distribution network, the safe and stable operation of the distribution network is seriously threatened, and it is difficult to satisfy the demand for preservation of supply. Multi-agent reinforcement learning provides an idea of zonal balance control, but it is difficult to fully satisfy operation constraints. In this paper, a multi-level control framework based on a local physical model and a multi-agent sequential update algorithm is proposed. The framework generates parameters through an upper-layer reinforcement learning algorithm, which are passed into the objective function of the lower-layer local physical model. The lower-layer local physical model will incorporate safety constraints to determine the power setpoints of the devices; meanwhile, the sequential updating algorithm is integrated into a centralized training–decentralized execution framework, which can increase the efficiency of the sample utilization and promote the monotonic improvement of the strategies. The modified 10 kV IEEE 69-node system is studied as an example, and the results show that the proposed framework can effectively reduce the total operating cost of the active distribution network, while meeting the demand of the system to preserve the supply and ensure the safe and stable operation of the system. Full article

Numerical simulations were performed to rapidly predict and evaluate laser beam expansion caused by linear atmospheric transmission effects, such as turbulence and jitter, thereby enhancing the accuracy of the scaling law. Simulation results indicate that the turbulence term coefficient in the beam expansion calibration expression correlates linearly with the initial beam mass and inversely with the transmission distance. By fitting a nonlinear surface, the relationship between the turbulence term coefficient, initial beam mass, and transmission distance was established. Additionally, under turbulence-free conditions, a calibration expression relating initial beam mass to transmission distance was derived. The tracking jitter-term coefficient was determined to be 3.69, effectively characterizing beam expansion due to system jitter error. Based on simulation outcomes, a scaling law model for beam expansion induced by linear atmospheric transmission effects was clearly established. The model closely matched the simulation data, with a root mean square error (RMSE) of 3.88. Compared with existing scaling law simulations, the proposed calibration expression significantly enhances the accuracy in predicting and evaluating beam expansion caused by linear atmospheric transmission effects. It also provides a more precise characterization of variations in beam expansion during laser transmission. Full article

Non-glaucous wheat can reduce solar light reflection in low-light cultivation regions, enhancing photosynthetic efficiency and potentially increasing yield. In previous work, a non-glaucous cuticular line, YL-429, was discovered in derivatives of pentaploid hybrids by crossing the synthetic wheat LM/AT23 (non-glaucous cuticular) with its tetraploid donor parent LM (glaucous) and selfing to F₇ generations. In the present study, multicolor fluorescence in situ hybridization was used to characterize the karyotype of the YL-429 line; genome resequencing was performed to identify the breakpoint of the 2D-2A chromosome translocation of YL-429; and bulk sequencing analysis was conducted to detect the SNP in the translocated fragment and accordingly develop specific kompetitive allele-specific PCR markers for use in breeding. The line YL-429 was preliminarily determined as a 2DS and 2AS translocation (LM T2DS-2AS.2AL) line through karyotyping. Genome alignment identified an approximately 13.8 Mb segment, including the wax inhibitor gene Iw2, in the telomeric region of the 2DS chromosome arm replacing an approximately 16.1 Mb segment in that of the 2AS chromosome arm. According to the bulk DNA sequencing data, 27 specific KASP markers were developed for detecting the translocated fragment from the 2DS of Aegilops tauschii. The LM T2DS-2AS.2AL translocation line YL-429 could be helpful in improving the photosynthesis of durum wheat cultivated in low-light cultivation regions. The developed markers can assist the screening of the T2DS-2AS.2AL translocation in breeding. Full article

Poly(butylene adipate-co-terephthalate) (PBAT) is a promising degradable polymer for replacing non-degradable traditional plastics to mitigate pollution. However, its low softening temperature and poor hardness impede its application. Herein, PBAT and stereocomplex polylactide (sc-PLA) blends were fabricated through a melt-blending process to balance the heat resistance and mechanical strength of PBAT in this research. The effects of the PLA content and hot embossing temperature on the blend properties were comprehensively investigated. The results demonstrate that the sc-crystal content in the PBAT/sc-PLA blend increased by 493% as the PLA content rose from 10% to 30%. The blend with 15% PLLA and 15% PDLA, hot embossed at 190 °C, exhibited the highest sc-PLA crystallinity of 23.3% and the largest fraction of sc-crystallites at 66%, leading to the optimal comprehensive performance. Its Vicat softening temperature (VST) reached 92.2 °C, and a nonlinear increase trend in accordance with the power-law model between VST and the mass ratio of sc-crystal was obtained. Compared with the mechanical properties of neat PBAT, a maximum tensile yield stress of 9.7 MPa and a Young’s modulus of 82.5 MPa were achieved and improved approximately by 107% and 361%, respectively. This research offers an effective strategy for synergistically enhancing the heat resistance and mechanical strength of PBAT. Full article

Salt stress is a significant environmental factor that impedes maize growth and yield. Exogenous 5-aminolevulinic acid (ALA) has been shown to mitigate the detrimental effects of various environmental stresses on plants. However, its regulatory role in the photosynthesis mechanisms of maize seedlings under salt stress remains poorly understood. Transcriptome sequencing and physiological index measurements were conducted on the leaves of the “Zhengdan 958” cultivar subjected to three different treatments. Differential expression analysis revealed 4634 differentially expressed genes (DEGs), including key transcription factor (TF) families such as NAC, MYB, WRKY, and MYB-related, across two comparisons (SS_vs_CK and ALA_SS_vs_SS). Significant enrichment was observed in the metabolic pathways related to porphyrin metabolism, photosynthesis-antenna proteins, photosynthesis, and carbon fixation in photosynthetic organisms. ALA treatment modulated the expression of photosynthesis-related genes, increased photosynthetic pigment content, and enhanced the activities of superoxide dismutase (SOD) and catalase (CAT), thereby mitigating the excessive accumulation of reactive oxygen species (ROS). Furthermore, ALA increased starch content under salt stress. These findings establish a foundational understanding of the molecular mechanisms through which ALA regulates photosynthesis under salt stress in maize seedlings. Collectively, exogenous ALA enhances maize’s salt tolerance by regulating photosynthesis-related pathways. Full article

Aeromonas species are among the main pathogens causing rainbow trout infections. Silver nanoparticles (AgNPs) have a broad spectrum of antimicrobial properties and are usually produced by various green-synthesis methods. However, the application of commercialized AgNPs has not fully been clarified. Thus, the objective of this study was to evaluate the antibacterial activities of commercialized AgNPs (range of sizes 10–12 nm) on two contrasting A. salmonicida strains (I-1 and I-4), isolated from rainbow trout; the antibacterial mechanism, histopathological alterations and the expression of immune-related genes were investigated. In vitro, the minimal inhibitory concentration (MIC) was 10 µg/mL for I-1, and lowered to 9.5 µg/mL for I-4, respectively. AgNPs were shown to disrupt both the cell wall and membrane of I-1 and I-4, resulting in cell lysis and degradation. In vivo, rainbow trout challenged by immersed or intraperitoneally injected infection, the 10 µg/mL AgNP-treated groups, both showed delayed deaths and lower mortalities compared to the control groups, without any clinical signs and pathological changes. Especially for the virulent I-4, the enhanced expressions of immune-related genes TNF-α, IL-1β, IL-10 and IL-11 were significantly reduced in the AgNP-treated group, indicating a lesser inflammation due to the application of AgNPs. This study would lay theoretical foundation for the wide application of silver nanoparticles in fish diseases. Full article

Breast cancer is a common clinical malignant tumor that seriously threatens women’s physical and mental health. Chemotherapy, as the first choice of breast cancer treatment, has limited its application in the clinic due to problems of poor stability, short half-life, and serious toxic side effects. With the emergence of nanotechnology, inorganic materials to prepare mesoporous silica nanoparticles (MSNs) have been widely used in anti-tumor drug carriers. However, their slow degradation rate limits their application in the biomedical field. Therefore, developing low-toxicity MSNs with good biocompatibility, biodegradability, and rapid release at the tumor site is a key scientific issue to be addressed. Here, we prepared DOX-loaded Ca-Mg-doped MSNs by electrostatic adsorption to obtain Ca-Mg@DOX@MSNs with suitable particle sizes and zeta potential, and the incorporation of calcium and magnesium also led to an increase in the degradation rate under acidic conditions and an accelerated release, which reduced the toxicity of DOX and promoted cellular uptake with good anti-tumor effects. This study provides a new idea for the clinical treatment of breast cancer. Full article

Drought constitutes a noteworthy abiotic stressor, detrimentally impacting seed germination, plant development, and agricultural yield. In response to the threats imposed by climate change and water paucity, this study examined the morphological divergence and genetic governance of drought resilience traits at the germination stage in 196 rapeseed (Brassica napus L.) lines under both normal (0 MPa) and drought-induced stress (−0.8 MPa) scenarios. Our study showed that the composite drought tolerance D value is a reliable index for identifying drought resilience. Through a genome-wide association study (GWAS), we uncovered 37 significant SNP loci and 136 putative genes linked to drought tolerance based on the D value. A key discovery included the gene BnaA01g29390D (BnNCED3), encoding 9-cis-epoxycarotenoid dioxygenase, which exhibited significantly heightened expression levels in drought-resistant accessions (p < 0.01), underscoring its potential as a positive drought stress regulator and a suitable candidate for genetically enhancing drought resilience. Moreover, we pinpointed four stress-reactive transcription factors (BnaA07g26740D, BnaA07g26870D, BnaA07g26910D, and BnaA07g26980D), two E3 ubiquitin-protein ligases (BnaA05g22900D and BnaC06g28950D), two enzymes (BnaA01g29390D and BnaA03g48550D), and two photosystem-associated proteins (BnaA05g22950D and BnaC06g28840D) as vital components in drought response mechanisms. The construction of a regulatory network reveals an ABA-dependent pathway (NCED3/RGLG5/IDD14) that contributes to drought tolerance in rapeseed seedlings, alongside the involvement of a drought avoidance strategy (APRR6/PHYB). The SNPs and genes unveiled in this study offer a substantial theoretical foundation for subsequent investigations targeting genetic improvement for drought resilience during seed germination in rapeseed. Full article

The multidrug and toxic compound extrusion (MATE) family is the latest class of novel secondary transporters discovered in plants. However, there is currently no comprehensive analysis of the MATE gene family in the tea plant. In this study, 68 CsMATE genes were identified from the tea plant genome using bioinformatic methods. In general, we analyzed the evolutionary relationships, intron–exon structure, distribution in chromosomes, conserved domains, and gene expression patterns in different tissues and stresses of the CsMATE gene family. The 68 CsMATEs were phylogenetically divided into four major clusters (Class I to Class IV). The CsMATE genes within the same class exhibit similar structural features, while displaying certain distinctions across different classes. Evolutionary analysis indicated that the CsMATE gene family expanded mainly through gene duplication events, in addition to proximal duplication. Through the analysis of cis-acting elements, it was found that CsMATE genes may be involved in the growth, development, and stress response. Furthermore, we observed that certain CsMATE genes could be induced to exhibit expression under abiotic stress conditions such as low temperature, high salinity (NaCl), osmotic stress (PEG), and methyl jasmonate treatment (MeJA). The findings presented herein offer a crucial theoretical foundation for elucidating the biological functions of CsMATE genes, particularly in response to abiotic stress, and furnish valuable potential genetic resources for tea plant resistance breeding. Full article

The assessment of wind energy resources is critical for the transition from fossil fuel to renewable energy sources. Using the outputs from high-resolution global climate models (GCMs), such as the High Resolution Model Intercomparison Project (HighResMIP) of the Coupled Model Intercomparison Project Phase 6 (CMIP6), has become one of the most important tools in wind energy research. This study evaluated the reliability of the 22 GCMs available in the HighResMIP-PRIMAVERA project by simulating the wind energy climatology and variability over the Tibetan Plateau (TP) with reference to observations and investigated the differences in performance of the GCMs between high-resolution (HR) and low-resolution (LR) simulations. The results show that most models performed relatively well in simulating the probability distribution of the observed wind speed over the TP, but nearly half of the models generally underestimated the wind speed, whereas the others tended to overestimated the wind speed. Compared with the wind speed, the GCMs showed larger biases in reproducing the wind power density (WPD) and other wind energy resources, whereas the biases in multi-model ensembles were relatively smaller than those in most individual models. With respect to interannual variability, both the HR and LR models failed to capture interannual variations in WPD over the TP. Furthermore, more than half of the HR GCMs had a reduced bias relative to the corresponding LR GCMs, indicating the good performance of most HR models in simulating wind energy resources over the TP in terms of spatial pattern and temporal variability. However, the overall performance of HR GCMs varied among models, which suggests that solely improving the horizontal resolution is not sufficient to completely solve the uncertainties and deficiencies in the simulation of wind energy over complex terrain. Full article

Low-frequency pulsating ripples exist on the input side of a single-phase inverter, which bring some adverse effects and harm to the inverter and photovoltaic power generation system. In order to suppress the low-frequency pulsating ripple and reduce the filter circuit parameters, a novel single-stage boost single-phase inverter is proposed, which can suppress low-frequency ripple. And a three-closed-loop compound control strategy that can suppress input low-frequency ripples under the limitation of an energy storage inductor current and buffer capacitor voltage is proposed. The circuit topology, control strategy, key circuit parameters design, system modeling, and simulation of the inverters are deeply analyzed and studied. Simulation and experimental results show that the inverter has a good ability to suppress input low-frequency ripples. Full article

In our previous research, we found that trichokonins’ (TKs) employment improved the thermotolerance of the Lanzhou lily, a renowned edible crop species endemic to China that is relatively susceptible to high temperatures (HTs). Here, a novel Lanzhou lily GRAS gene, LzSCL9, was identified to respond to heat stress (HS) and HS+TKs treatment based on transcriptome and RT-qPCR analysis. TKs could improve the upregulation of LzSCL9 during long-term HS. The expression profile of LzSCL9 in response to HS with or without TKs treatment showed a significant positive correlation with LzHsfA2a-1, which was previously identified as a key regulator in TKs’ conferred resilience to HT. More importantly, overexpression of LzSCL9 in the lily enhanced its tolerance to HTs and silencing LzSCL9 in the lily reduced heat resistance. Taken together, this study identified the positive role of LzSCL9 in TK-induced thermotolerance, thereby preliminarily establishing a molecular mechanism on TKs regulating the thermostability of the Lanzhou lily and providing a new candidate regulator for plant heat-resistant breeding. Full article

In order to determine the appropriate harvesting period of Carya illinoinensis planted in Nanjing city of China, this study analyzed the phenotypic characteristics and inclusions, including single fruit quality, fruit transverse and vertical diameter, kernel rate, water content, color, respiratory strength, crude fat, soluble sugar, soluble protein, and total phenols, of two cultivars ‘Pawnee’ and ‘Wichita’ during September and October, respectively. Results showed that the respiration intensity and I_AD values of pecan fruits decreased as the harvest date was delayed. ‘Pawnee’ fruits exhibited the highest seed kernel fullness, ∆E value, fruit transverse diameter, shape index, kernel yield, crude fat, and total phenolic content in late September and early October, while the quality of ‘Wichita’ fruits reached its peak in late October. The appropriate harvest period is conducive to the material accumulation of Carya illinoinensis, which is of great practical significance for improving the commodity value of pecans. The optimal harvesting period for ‘Pawnee’ in Nanjing is from the end of September to the beginning of October, and the optimal harvesting period for ‘Wichita’ is from mid- to late-October to the end of October. Full article