Search

Isoflavonoids, the major secondary metabolites within the flavonoid biosynthetic pathway, play important roles in plant defense and exhibit free radical scavenging properties in mammals. Recent advancements in understanding the synthesis, transport, and regulation of isoflavonoids have identified their biosynthetic pathways as promising targets for metabolic engineering, offering potential benefits such as enhanced plant resistance, improved biomass, and restoration of soil fertility. This review provides an overview of recent breakthroughs in isoflavonoid biosynthesis, encompassing key enzymes in the biosynthetic pathway, transporters influencing their subcellular localization, molecular mechanisms regulating the metabolic pathway (including transcriptional and post-transcriptional regulation, as well as epigenetic modifications). Metabolic engineering strategies aimed at boosting isoflavonoid content in both leguminous and non-leguminous plants. Additionally, we discuss emerging technologies and resources for precise isoflavonoid regulation. This comprehensive review primarily focuses on model plants and crops, offering insights for more effective and sustainable metabolic engineering approaches to enhance nutritional quality and stress tolerance. [ABSTRACT FROM AUTHOR]

To address the issues of sluggish response and inadequate precision in traditional gate opening control systems, this study presents a novel approach for direct current (DC) motor control utilizing an enhanced beetle antennae search (BAS) algorithm to fine-tune the parameters of a fuzzy proportional integral derivative (PID) controller. Initially, the mathematical model of the DC motor drive system is formulated. Subsequently, employing a search algorithm, the three parameters of the PID controller are optimized in accordance with the control requirements. Next, software simulation is employed to analyze the system's response time and overshoot. Furthermore, a comparative analysis is conducted between fuzzy PID control based on the improved beetle antennae search algorithm, and conventional approaches such as the traditional beetle antennae search algorithm, the traditional particle swarm algorithm, and the enhanced particle swarm algorithm. The findings indicate the superior performance of the proposed method, characterized by reduced oscillations and accelerated convergence compared to the alternative methods. [ABSTRACT FROM AUTHOR]

Corn straw is one kind of agricultural by-product containing 70–80% insoluble dietary fiber (IDF). In order to develop corn straw dietary fiber, this study was conducted to increase soluble dietary fiber (SDF) yield and improve the structure, functional and prebiotic properties of IDF and SDF from corn straw treated by alkali oxidation treatment, enzymatic hydrolysis, microbial fermentation and the combination of these methods. The results demonstrated that the yield of SDF was significantly increased from 2.64% to 17.15% after corn straw was treated by alkali oxidation treatment + Aspergillus niger fermentation + cellulase hydrolysis, compared with untreated corn straw. The SDF extracted from corn straw treated by alkali oxidation treatment + Aspergillus niger fermentation + cellulase hydrolysis (F-SDF) exhibited a honeycomb structure, low crystallinity (11.97%), good antioxidant capacity and high capacities of water holding, water solubility and cholesterol absorption and promoted short-chain fatty acids production by chicken cecal microbial fermentation in vitro. F-SDF enhanced the antibacterial activity against Escherichia coli and Staphylococcus aureus proliferations of Lactobacillus plantarum when it was used as a substrate for Lactobacillus plantarum fermentation. It could be concluded that the combined treatments could increase SDF yield from corn straw and improve its functional and prebiotic properties. [ABSTRACT FROM AUTHOR]

Physical unclonable functions (PUFs) have emerged as a promising encryption technology, utilizing intrinsic physical identifiers that offer enhanced security and tamper resistance. Multi‐level PUFs boost system complexity, thereby improving system reliability and fault tolerance. However, crosstalk‐free multi‐level PUFs remain a persistent challenge. In this study, a hierarchical PUF system that harnesses the spontaneous phase separation of silk fibroin /PVA blend and the random distribution of silicon‐vacancy diamonds within the blend is presented. The thermodynamic instability of phase separation and inherent unpredictability of diamond dispersion gives rise to intricate random patterns at two distinct scales, enabling time‐efficient hierarchical authentication for cryptographic keys. These patterns are complementary yet independent, inherently resistant to replication and damage thus affording robust security and reliability to the proposed system. Furthermore, customized authentication algorithms are constructed: visual PUFs authentication utilizes neural network combined structural similarity index measure, while spectral PUFs authentication employs Hamming distance and cross‐correlation bit operation. This hierarchical PUF system attains a high recognition rate without interscale crosstalk. Additionally, the coding capacity is exponentially enhanced using M‐ary encoding to reinforce multi‐level encryption. Hierarchical PUFs hold significant potential for immediate application, offering unprecedented data protection and cryptographic key authentication capabilities. [ABSTRACT FROM AUTHOR]

Blue lasers are integral to a variety of applications, including marine communication, underwater resource exploration, cold laser processing, laser medicine, and beyond. Vertical external cavity surface-emitting lasers (VECSELs) have the advantages of high output power and tunable wavelength, and can output blue laser via frequency doubling. In this article, a new type of intracavity beam control external-cavity structure is introduced. The laser beam waist is effectively adjusted by intracavity beam control, and the frequency conversion efficiency is improved. A laser cavity stability analysis model was developed to investigate the impact of laser cavity lens parameters and relative positions on stability. The external resonant cavity of VECSELs utilizes two optical lenses to position the beam waist near the laser output coupling mirror and locates the frequency doubling crystal at a high optical power density position to optimize frequency conversion efficiency. The VECSEL straight external-cavity structure achieves a frequency conversion efficiency of up to 60.2% at 488 nm, yielding a blue laser output exceeding 1.3 W. The full width at half maximum of the 488 nm spectrum measures approximately 0.23 nm. This intracavity beam-controlled direct external-cavity structure effectively mitigates laser mode leakage and shows potential for the development of an efficient and compact blue laser source. [ABSTRACT FROM AUTHOR]

Polyether amines are versatile compounds characterized by a flexible structure, consisting of polyoxypropylene and polyoxyethylene as the backbone, with amine groups at each end. They have widespread applications in various industrial processes and daily life. Despite their versatility, the utilization of polyether amines as base catalysts is rare. In this study, one kind of three-arm polyether amine 1 was employed as an environmentally friendly, cost-effective catalyst for the aerobic oxidation of thiophenols, leading to the synthesis of disulfides. The oxidative coupling of thiols serves as a fundamental pathway for the production of disulfides, which are vital in both chemical and biological processes. In contrast to known methods for thiol oxidation, this polyether amine-based catalytic process eliminates the need for expensive stoichiometric oxidants and minimizes the formation of over-oxidized by-products. Using a mere 0.5 mol % of the polyether amine 1 as the catalyst, a remarkable > 96% yield was achieved for all 16 tested substrates, encompassing a diverse range of functional groups, under the catalytic aerobic oxidation conditions. Furthermore, it is noteworthy that over 90% of the polyether amine catalyst can be efficiently recovered for reuse without loss of activity, making this a sustainable and cost-effective catalytic approach. [ABSTRACT FROM AUTHOR]

Polarization-insensitive semiconductor optical amplifiers (SOAs) in all-optical networks can improve the signal-light quality and transmission rate. Herein, to reduce the gain sensitivity to polarization, a multi-quantum-well SOA in the 1550 nm band is designed, simulated, and developed. The active region mainly comprises the quaternary compound InGaAlAs, as differences in the potential barriers and wells of the components cause lattice mismatch. Consequently, a strained quantum well is generated, providing the SOA with gain insensitivity to the polarization state of light. In simulations, the SOA with ridge widths of 4 µm, 5 µm, and 6 µm is investigated. A 3 dB gain bandwidth of >140 nm is achieved with a 4 µm ridge width, whereas a 6 µm ridge width provides more output power and gain. The saturated output power is 150 mW (21.76 dB gain) at an input power of 0 dBm but increases to 233 mW (13.67 dB gain) at an input power of 10 dBm. The polarization sensitivity is <3 dBm at −20 dBm. This design, which achieves low polarization sensitivity, a wide gain bandwidth, and high gain, will be applicable in a wide range of fields following further optimization. [ABSTRACT FROM AUTHOR]

In order to improve the wear resistance of 45 steel, in this study, WC/Ni60 composite coatings with different CeO2 additions (0, 1, 2, and 3 wt%) were prepared on 45 steel by the laser cladding technique; the experimental analysis was carried out by means of scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD), a Vickers hardness tester, and a friction and wear tester. The results show that CeO2 had little effect on the phase composition of the coatings; however, with the increase in CeO2 content, the CeO2 played a key role in refining the grains of the coating, thus reducing the generation of cracks. In addition, CeO2 could effectively strengthen the internal structure of the coating and improve its microhardness and wear resistance. Particularly noteworthy is the observed reduction in both the friction coefficient and mass loss of the coating when the CeO2 addition reached 2%. This suggests an enhancement in the tribological performance of the coating at this concentration. [ABSTRACT FROM AUTHOR]

This article presents a coil couple-based transcutaneous energy transmission system (TETS) for wirelessly powering implanted artificial hearts. In the TETS, the performance of the system is commonly affected by the change in the position of the coupling coils, which are placed inside and outside the skin. However, to some extent, the influence of coupling efficiency caused by misalignment can be reduced by optimizing the coil. Thus, different types of coils are designed in this paper for comparison. It has been found that the curved coil better fits the surface of the skin and provides better performance for the TETS. Various types of curved coils have been designed in response to observed bending deformations, dislocations, and other coupling variations in the curved coil couple. The numerical model of the TETS is established to analyze the effects of the different types of coils. Subsequently, a series of experiments are designed to evaluate the resilience to misalignment and to verify the heating of the coil under conditions of severe coupling misalignment. The results indicated that, in the case of misalignment of the coils used in artificial hearts, the curved transmission coil demonstrated superior efficiency and lower temperature rise compared to the planar coil. [ABSTRACT FROM AUTHOR]

It is crucial to fully understand the degradation law of commercial LiFePO4 lithium-ion batteries (LIBs) in terms of their health and safety status under different operating conditions, as well as the degradation mechanism and influencing factors. This work investigates the evolution patterns of cycling performance in commercial LiFePO4 batteries under different operating conditions, including temperature, electrolyte, charge/discharge rate, and depth of cycling. Structure characterization tests on electrode materials before and after long-term cycles have been carried out to elucidate the failure/degradation mechanisms during battery operation. It has been found that it is a comprehensive effect from different operation conditions that results in performance degradation. Fe element shuttling and Li deposition may cause internal decay of LiFePO4 LIBs. Additionally, working temperatures and the rate and depth of discharge (DOD) should be strictly controlled to achieve high energy retention and long life. This study proposes a perspective that explores the impact of internal and external factors on the degradation of the safety performance in LiFePO4 LIBs, with the aim of improving the safe and stable operation of large-scale LiFePO4 LIB energy storage systems, as it is favorable to unravel their complex multi-dimensional evolution mechanism and coupling effects throughout their life cycle. [ABSTRACT FROM AUTHOR]

A key factor in the photoelectrochemical (PEC) performance of photoelectrodes is the efficient separation and transfer of photogenerated charges. Herein, a novel photoanode comprising three‐dimensional (3D) WO3 nanoplate@ZnO nanosheet hierarchical type‐II heterojunction arrays (3D WO3@ZnO HHAs) is designed and constructed via modification of the WO3 nanoplate arrays with ZnO nanosheets. The synthesized materials are characterized viaX‐ray diffraction (XRD), ultraviolet and visible spectrophotometry (UV–vis), scanning electon microscopy (SEM), transmission electron microscopy (TEM), and X‐ray photoelectron spectroscopy (XPS) analyses. Photoelectrochemical (PEC) test results reveal that the synthesized 3D WO3@ZnO HHAs photoanode exhibits reduced charge transfer resistance, improved electron‐hole pair life, and enhanced photocurrent density (≈4.5 times increase in comparison to that of the bare WO3). The increased light capture and high surface area in contact with the electrolyte as well as the enhanced charge transfer through the synergy between morphology and band structures may be responsible for the improved PEC characteristics. [ABSTRACT FROM AUTHOR]

Emotion recognition utilizing EEG signals has emerged as a pivotal component of human–computer interaction. In recent years, with the relentless advancement of deep learning techniques, using deep learning for analyzing EEG signals has assumed a prominent role in emotion recognition. Applying deep learning in the context of EEG-based emotion recognition carries profound practical implications. Although many model approaches and some review articles have scrutinized this domain, they have yet to undergo a comprehensive and precise classification and summarization process. The existing classifications are somewhat coarse, with insufficient attention given to the potential applications within this domain. Therefore, this article systematically classifies recent developments in EEG-based emotion recognition, providing researchers with a lucid understanding of this field's various trajectories and methodologies. Additionally, it elucidates why distinct directions necessitate distinct modeling approaches. In conclusion, this article synthesizes and dissects the practical significance of EEG signals in emotion recognition, emphasizing its promising avenues for future application. [ABSTRACT FROM AUTHOR]

Broad-area lasers (BALs) have found applications in a variety of crucial fields on account of their high output power and high energy transfer efficiency. However, they suffer from poor spatial beam quality due to multi-mode behavior along the waveguide transverse direction. In this paper, we propose a novel metasurface waveguide structure acting as a transverse mode selective back-reflector for BALs. In order to effectively inverse design such a structure, a digital adjoint algorithm is introduced to adapt the considerably large design area and the high degree of freedom. As a proof of the concept, a device structure with a design area of 40 × 20 μm2 is investigated. The simulation results exhibit high fundamental mode reflection (above 90%), while higher-order transverse mode reflections are suppressed below 0.2%. This is, to our knowledge, the largest device structure designed based on the inverse method. We exploited such a device and the method and further investigated the device's robustness and feasibility of the inverse method. The results are elaborately discussed. [ABSTRACT FROM AUTHOR]

Altering the content of an alloying element in alloy materials will inevitably affect the content of other elements, while the effect is frequently disregarded, leading to subsequent negligence of the common influence on the physical properties of alloys. Therefore, the correlation between alloying elements and physical properties has not been adequately addressed in the existing studies. In response to this problem, the present study focuses on the Al10Ti15Nix1Crx2Cox3 alloys and investigates the competitive interplay among Ni, Cr, and Co elements in the formation of physical properties through a single-element (SE) analysis and a multi-element (ME) analysis based on the first principles calculations and the partial least squares (PLS) regression. The values of C11 and C44 generally increase with the incorporation of Ni or Cr content in light of SE analysis, which is contrary to the inclination of ME analysis in predicting the impact of Ni and Cr elements, and the Ni element demonstrates a pronounced negative competitive ability. The overall competitive relationship among the three alloying elements suggests that increasing the content of Ni and Cr does not contribute to enhancing the elastic constants of alloys, and the phenomenon is also observed in the analysis of elastic moduli. The reason is that the SE analysis fails to account for the aforementioned common influence of multiple alloying elements on the physical properties of alloys. Therefore, the integration of SE analysis and ME analysis is more advantageous in elucidating the hidden competitive mechanism among multiple alloying elements, and offering a more robust theoretical framework for the design of alloy materials. [ABSTRACT FROM AUTHOR]

The impact of variations in the content of single alloying element on the properties of alloy materials has been extensively discussed, but the influence of this change on the content of multiple alloying elements in the alloy materials has been disregarded, as the performances of alloy materials should be determined by the collective influence of multiple alloying elements. To address the aforementioned issue, the present study conducted a comprehensive investigation into the impact of variations in the content of alloying elements, namely Ni, Cr, and Co, on the structural and mechanical properties of L12-(Nix1Crx2Cox3)3Al precipitates using the high-throughput first-principles calculations and the partial least squares (PLS) regression, and the competitive mechanism among these three elements was elucidated. The findings demonstrate that the same alloying element may exhibit opposite effects in both single element analysis and comprehensive multi-element analysis, for example, the effect of Ni element on elastic constant C11, and the influence of Cr element on Vickers hardness and yield strength. The reason for this is that the impact of the content of other two alloying elements is ignored in the single element analysis. Meanwhile, the Co element demonstrates a significant competitive advantage in the comparative analysis of three alloying elements for different physical properties. Therefore, the methodology proposed in this study will facilitate the elucidation of competition mechanisms among different alloy elements and offer a more robust guidance for experimental preparation. [ABSTRACT FROM AUTHOR]

The transport properties of molecular devices based on carbon chains are systematically investigated using a combination of non-equilibrium Green's function (NEGF) and density functional theory (DFT) first-principle methods. In single-carbon-chain molecular devices, a distinct even–odd behavior of the current emerges, primarily influenced by the density of states (DOS) within the chain channel. Additionally, linear, monotonic currents exhibit Ohmic contact characteristics. In ladder-shaped carbon-chain molecular devices, a notable current stabilization behavior is observed, suggesting their potential utility as current stabilizers within circuits. We provide a comprehensive analysis of the transport properties of molecular devices featuring ladder-shaped carbon chains connecting benzene-ring molecules. The occurrence of negative differential resistance (NDR) in the low-bias voltage region is noted, with the possibility of manipulation by adjusting the position of the benzene-ring molecule. These findings offer a novel perspective on the potential applications of atom chains. [ABSTRACT FROM AUTHOR]

In marine engineering and water conservancy projects, dredging often occurs due to silt accumulation, which can impede the long-term development of water ecosystems and water storage systems. To enhance dredging efficiency and the performance of dredging machines, a novel type of winch suction underwater dredging robot was designed. Computational fluid dynamics software was utilized to establish a fluid model of the robot's winch suction dredging device and conduct model simulation experiments. The simulation test results were used to investigate the factors influencing dredging performance and their impact laws. Five key factors—namely, the reamer rotational speed, reamer arrangement angle, water flow rate, inlet pipe diameter, and outlet pipe diameter—were selected for consideration. By setting up various sets of factor levels, the significant influence of different factors on dredging efficiency was examined. Analysis of variance was employed to analyse the results of the orthogonal experimental design, leading to the identification of optimal factor levels and the establishment of an optimal scheme group. The results of the optimal scheme were verified, demonstrating a 13.049% increase in dredging efficiency and a 19.23% decrease in power consumption of the sludge pump compared to the initial experimental setup. The performance of the optimal program surpassed that of all the experimental designs and met the design requirements. [ABSTRACT FROM AUTHOR]

Quantifying the allocation of photosynthetic products among different carbon (C) pools is critical for understanding and predicting plant C turnover response to climate change. A field experiment with ectomycorrhizal fungi (EMF) and nitrogen (N) was established to investigate the effects on allocation of photosynthetic products in Pinus massoniana (Lamb.) seedlings given increased N deposition. Seedlings were subjected to N addition and symbiosis with EMF, and the short-term allocation of a 13C photosynthetic pulse into leaves, branches, stems, roots, and soil was traced. Photosynthetic rate and root respiration were measured. It was found that N addition changed the allocation pattern of photosynthetic products in various organs of P. massoniana. Furthermore, N addition, mycorrhizal symbiosis, and interaction of N and EMF, all increased the amount of C produced by photosynthesis. N application less than 60 kg N hm–1 a–1 could promote the transfer and allocation of photosynthetic products in P. massoniana organs, which peaks at 60 kg N hm–1 a–1, and the highest N treatment began to decrease at 90 kg N hm–1 a–1. EMF inoculation could expand the absorption area of plant roots to obtain more nutrients and synthesize more C and N compounds for promoting the growth of itself and the host plant, improving the net photosynthetic rate and the distribution of C produced by photosynthesis in various organs. This forms a benign C and N cycle, thereby reducing the effect of high N addition on plants. The optimal N addition concentration was 60 kg N hm–1 a–1, and the optimal EMF was Pt, which provides a theoretical basis for inoculating EMF during increasing N deposition in the future climate change scenario. This enables plants to distribute more photosynthetic products to their roots, thus affecting their own C distribution for promoting growth.