Control of a Micro-Electro-Mechanical System Fast Steering Mirror with an Input Shaping Algorithm.

Fast steering mirrors (FSMs) designed by the micro-electro-mechanical system (MEMS) technology are significantly smaller in volume and mass, offering distinct advantages. To improve their performance in the open-loop control mode, this study introduces a control algorithm and evaluates its performance on an electromagnetic-driven MEMS-FSM. The algorithm employs a method to shape the input signal by fitting the system's transfer function and modifying the step response. This shaped signal is then applied to the system to minimize overshoot, reduce settling time, and improve working bandwidth, thereby enabling faster angular adjustments and improving the stability of the FSM. The experimental results demonstrate an 85.65% reduction in overshoot and a decrease in settling time from 84 ms to 0.4 ms. Consequently, the working bandwidth of the FSM system increases to 2500 Hz, demonstrating the effectiveness of the algorithm in enhancing MEMS-FSM's performance.

Integrating Network Pharmacology and Experimental Validation to Investigate the Mechanism of Qushi Huatan Decoction Against Coronary Heart Disease.

Purpose: This study was designed to evaluate the effect and mechanism of the Qushi Huatan (QSHT) decoction against coronary heart disease (CHD) through network pharmacology and experimental verification. Methods: In the present study, the active ingredients of the QSHT decoction were identified by ultra performance liquid chromatography/tandem mass spectrometry (UPLC/MS), then the potential ingredients and coronary heart disease targets were predicted using the SwissTarget Prediction database and the database of Genecards and OMIM database, respectively. A herb-compound-target network was constructed using Cytoscape. GO and KEGG enrichment analysis were performed using the ClusterProfiler data package of R software. Molecular docking was used to predict the core targets of QSHT against CHD. In addition, we used a myocardial infarction (MI) and high-fat diet ApoE-/- mice model to investigate the cardioprotective effects of QSHT. Western blotting and immunochemistry were used to verify the core targets and the signaling pathway. Results: A total of 68 active ingredients were found in the QSHT decoction. Network pharmacology indicated 28 targets and 147 signal pathways, including AKT1, HIF-1α, GSK-3ß, TLR4 and NF-κB, those key targets were also verified by molecular docking. The results of GO and KEGG enrichment analysis showed that the targets of QSHT against CHD were largely associated with inflammatory and oxidative stress, and AKT/HIF-1α and TLR4/NF-κB pathways might be key functional pathways. In vivo, QSHT significantly improved cardiac function and attenuated fibrosis and inflammation. Furthermore, QSHT could significantly inhibit the expression of HIF-1α, TLR4, phosphorylation of AKT1, GSK-3ß and NF-κB after MI in ApoE-/- mice. Conclusion: Based on network pharmacology, molecular docking and experimental verification, this study demonstrated that QSHT could improve cardiac function and attenuate cardiac fibrosis by regulating TLR4/NF-κB and AKT/HIF-1α signaling pathway in post- MI and high-fat diet ApoE-/- mice.

Synthesis and in vitro evaluation of benzo[b]thiophene-3-carboxylic acid 1,1-dioxide derivatives as anticancer agents targeting the RhoA/ROCK pathway.

Rho family GTPases regulate cellular processes and promote tumour growth and metastasis; thus, RhoA is a potential target for tumour metastasis inhibition. However, limited progress has been made in the development of RhoA targeting anticancer drugs. Here, we synthesised benzo[b]thiophene-3-carboxylic acid 1,1-dioxide derivatives based on a covalent inhibitor of RhoA (DC-Rhoin), reported in our previous studies. The observed structure-activity relationship (contributed by carboxamide in C-3 and 1-methyl-1H-pyrazol in C-5) enhanced the anti-proliferative activity of the derivatives. Compound b19 significantly inhibited the proliferation, migration, and invasion of MDA-MB-231 cells and promoted their apoptosis. The suppression of myosin light chain phosphorylation and the formation of stress fibres confirmed the inhibitory activity of b19 via the RhoA/ROCK pathway. b19 exhibited a different binding pattern from DC-Rhoin, as observed in molecular docking analysis. This study provides a reference for the development of anticancer agents targeting the RhoA/ROCK pathway.

Association Between Weight-Adjusted Waist Index and Albuminuria in Type 2 Diabetes Mellitus in the Chinese Population.

Purpose: This study aimed to investigate the relationship between weight-adjusted waist index (WWI) and albuminuria in patients with type 2 diabetes mellitus (T2DM) in the Chinese population. Patients and Methods: A total of 860 adult patients in the Department of Endocrinology of the Affiliated Hospital of Jiangsu University were retrospectively analyzed from June 2018 to September 2023. Correlations between WWI and albuminuria (albumin-to-creatinine ratio (UACR) ≥ 30 mg/g were defined as albuminuria) were analyzed using the Pearson and Spearman methods. The associations between albuminuria and Age, gender, body mass index (BMI), waist circumference/ hip circumference (WHR), systolic blood pressure(SBP), diastolic blood pressure (DBP), fasting plasma glucose (FPG), 2-hour postprandial plasma glucose (2h PG), fasting plasma insulin (FIns), 2-h postprandial insulin (2hINS), glycosylated hemoglobin (HbA1c), WWI, homeostasis model assessment of insulin resistance (HOMA-IR) were analyzed via binary logistic regression. Results: Compared with the normal albumin group, serum urea nitrogen, serum creatinine, UACR, and WWI levels in the albuminuria group were significantly increased, while estimated glomerular filtration rate (eGFR) levels were significantly decreased (P < 0.05). Correlation analyses revealed that WWI was positively correlated with UACR but negatively correlated with urea nitrogen, serum creatinine, and eGFR (P < 0.05). Binary logistic regression analyses indicated that WWI was an independent risk factor for albuminuria in T2DM patients. Receiver operating characteristic curve results showed that the area under the curve for albuminuria as predicted by WWI was 0.605 [95% CI = (0.563-0.646), P < 0.001]. Conclusion: WWI is independently associated with albuminuria in the Chinese patients with type 2 diabetes and may serve as a simple indicator for albuminuria risk assessment.

Achieving the Inhibition of Aluminum Corrosion by Dual-Salt Electrolytes for Sodium-Ion Batteries.

Sodium bis(fluorosulfonyl)imide (NaFSI) electrolytes are renowned for their superior physicochemical and electrochemical properties, making them ideal for high-performance sodium-ion batteries (SIBs). However, severe oxidative dissolution of aluminum current collectors (commonly known as Al corrosion) in NaFSI-based electrolytes occurs at high potentials. To address this challenge, aiming to understand the Al corrosion mechanism and develop strategies to inhibit corrosion, we propose dual-salt electrolytes using 0.8 mol L-1 (M) NaFSI and 0.2 M of a second fluorine-containing sodium salt dissolved in EC/PC solutions (1:1, v/v) to construct an insoluble deposits layer on the Al. Dual-salt electrolytes adopting a second sodium salt capable of passivating the Al collector have been extensively investigated through various techniques, such as cyclic voltammetry, scanning electron microscopy, chronoamperometry, X-ray photoelectron spectroscopy, and charge-discharge tests. Our findings demonstrate that introducing sodium difluoro(oxalato)borate (NaDFOB) into the NaFSI electrolytes inhibits Al corrosion, which is attributed to the formation of insoluble deposits of Al-F (AlF3) and B-F containing polymers. Moreover, the capacity retention of Na||Na3V2(PO4)3 (NVP) cells using the NaFSI-NaDFOB dual-salt electrolyte reaches 99.2% along with a Coulombic efficiency over 99.3% at a 1 C rate after 200 cycles. This research provides a practical solution for passivating Al collectors in SIBs with NaFSI electrolytes and promotes the development of sodium batteries with long calendar lifetimes.

Improved-quality graphene films via the synergism of large nanosheet aligning and nanotube bridging for flexible supercapacitors.

Scalable production of reduced graphene oxide (rGO) films with high mechanical-electrical properties is desirable as these films are candidates for wearable electronics devices and energy storage applications. Removing structural incompleteness such as wrinkles or voids in the graphene films, which are generated from the assembly process, would greatly optimize their mechanical properties. However, the densely stacked graphene sheets in the films degrade their ionic kinetics and thus limit their development. Here, a horizontal-longitudinal-structure modulating strategy is demonstrated to produce enhanced mechanical, conductive, and capacitive graphene films. Typically, two-dimensional large graphene sheets (LGS) induce regular stacking of graphene oxide (GO) during the assembly process to reduce wrinkles, while one-dimensional single-walled carbon nanotubes (SWCNT) bridge with graphene sheets to strengthen the multidirectional intercalation and reduce GO layer restacking. The simultaneous incorporation of LGS and SWCNT synergistically creates a fine microstructure by improving the alignment of graphene sheets, increasing continuous conductive pathways to facilitate electron transport, and enlarging interlayer spacing to promote electrolyte ion diffusion. As a result, the obtained graphene films are flat and exhibit signally reinforced mechanical properties, electrical conductivity (38727 S m-1), as well as specific capacitance (232 F g-1) as supercapacitor electrodes compared to those of original rGO films. Moreover, owing to the comprehensive improved properties, a flexible gel supercapacitor assembled by the graphene film-based electrodes shows high energy density, good flexibility, and excellent cycling stability (93.8% capacitance retention after 10 000 cycles). This work provides a general strategy to manufacture robust graphene structural materials for energy storage applications in flexible and wearable electronics.

Artificial intelligence for neuro MRI acquisition: a review.

OBJECT: To review recent advances of artificial intelligence (AI) in enhancing the efficiency and throughput of the MRI acquisition workflow in neuroimaging, including planning, sequence design, and correction of acquisition artifacts. MATERIALS AND METHODS: A comprehensive analysis was conducted on recent AI-based methods in neuro MRI acquisition. The study focused on key technological advances, their impact on clinical practice, and potential risks associated with these methods. RESULTS: The findings indicate that AI-based algorithms have a substantial positive impact on the MRI acquisition process, improving both efficiency and throughput. Specific algorithms were identified as particularly effective in optimizing acquisition steps, with reported improvements in workflow efficiency. DISCUSSION: The review highlights the transformative potential of AI in neuro MRI acquisition, emphasizing the technological advances and clinical benefits. However, it also discusses potential risks and challenges, suggesting areas for future research to mitigate these concerns and further enhance AI integration in MRI acquisition.

Cultural differences in appraisals of control and posttraumatic stress disorder symptoms.

Background: Appraisals are central to posttraumatic stress disorder (PTSD). Yet, few studies have examined how culture influences the associations between different types of trauma-related appraisals and PTSD symptoms.Objective: This study investigated cultural influences on appraisals of control and their associations with PTSD symptoms.Method: European Australian (n = 140, Mage = 35.80, SD = 12.44; 21 men, 97 women, 20 gender diverse/prefer not to report) and Chinese Australian (n = 129, Mage = 30.16, SD = 8.93, 21 men, 97 women, 20 gender diverse/prefer not to report) trauma survivors completed measures of appraisals, cultural values, and PTSD symptoms.Results: Findings showed that the Chinese Australian group was associated with greater Chinese cultural beliefs about adversity (i.e. emphasizing the value of adversity and people's ability to overcome adversity) and fewer fatalism appraisals (i.e. appraising one's destiny as externally determined), which in turn were atemporally associated with fewer PTSD symptoms; these atemporal indirect associations were moderated by self-construal and holistic thinking. The Chinese Australian group also reported fewer secondary control appraisals (i.e. attempts to change aspects of the self and accept current circumstances), which were atemporally associated with greater PTSD symptoms. In contrast, the European Australian group was associated with fewer primary control appraisals (i.e. perceived ability to personally change or control a situation), which were atemporally associated with greater PTSD symptoms.Conclusion: These findings highlight the importance of considering the influence of culture on appraisals in PTSD. However, it must be noted that causal relationships cannot be inferred from cross-sectional mediation analyses and thus, future longitudinal research is needed.

Chinese Australian trauma survivors were associated with greater reporting of Chinese cultural beliefs about adversity and fewer fatalism appraisals, which were associated with fewer PTSD symptoms. These associations were moderated by a trauma survivor's self-construal and level of holistic thinking.Chinese Australian trauma survivors reported fewer secondary control appraisals, which were associated with greater PTSD symptoms.European Australian trauma survivors were associated with fewer primary control appraisals, which were associated with greater PTSD symptoms.

Advancing elastomer performance with dynamic bond networks in polymer-grafted single-chain nanoparticles: a molecular dynamics exploration.

This research introduces a method to enhance the mechanical properties of elastomers by grafting polymer chains onto single-chain flexible nanoparticles (SCNPs) and incorporating dynamic functional groups. Drawing on developments in grafting polymers onto hard nanoparticle fillers, this method employs the distinct flexibility of SCNPs to diminish heterogeneity and enhance core size control. We use molecular dynamics (MD) simulations for a mesoscale analysis of structural properties, particularly the effects of dynamic functional group quantities and their distribution. The findings demonstrate that increased quantities of functional groups are correlated with enhanced mechanical strength and toughness, showing improved stress-strain responses and energy dissipation capabilities. Moreover, the uniformity in the distribution of these functional groups is crucial, promoting a more cohesive and stable dynamic bonding network. The insights gained from MD simulations not only advance our understanding of the microstructural control necessary for optimizing macroscopic properties, but also provide valuable guidance for the design and engineering of advanced polymer nanocomposites, thereby enhancing the material performance through strategic molecular design.

Mental health literacy among Arab men living in high-income Western countries: A systematic review and narrative synthesis.

While interest in mental health literacy (MHL) is growing rapidly, cross-cultural research focusing on MHL is developing more slowly. This inaugural systematic review explored the recognition and beliefs about the causes of mental health disorders amongst Arab men living in high income Western countries (HIWC), their help-seeking beliefs, behaviors, and sources of help, as well as barriers and facilitators to help-seeking. Six electronic database searches were conducted using Medline, Embase, ProQuest Dissertations & Theses Global, PsycINFO, Scopus, and Web of Science. These searches yielded a total of 9,460 citations. After applying inclusion criteria through both database and manual hand searches, 46 studies were identified. The findings corresponded with four of the socioecological model's five factors: intrapersonal, interpersonal, societal, and institutional. Intrapersonal factors included attributing mental health illness to life and migration stressors, and religious reasons. Interpersonal and societal factors included men favoring informal help-seeking sources as stigma was a barrier to formal help-seeking. Institutional factors around the perceived cultural competence of healthcare professionals and access difficulties were obstacles to seeking formal help. The growth in Arab migration to HIWC highlights the need for culturally tailored care. Research is needed to understand the perspectives of healthcare providers working with Arab men in addition to how men's stigmatizing attitudes are an obstacle to formal help-seeking. Interventions should be designed to address the unique mental health needs of Arab men, recognizing that some explanatory beliefs may not align with current Western models of mental health. Moreover, efforts should be made to integrate men's informal sources of support into treatment planning.

Underwater dynamic polarization imaging without dependence on the background region.

Active-polarization imaging holds significant promise for achieving clear underwater vision. However, only static targets were considered in previous studies, and a background region was required for image restoration. To address these issues, this study proposes an underwater dynamic polarization imaging method based on image pyramid decomposition and reconstruction. During the decomposition process, the polarized image is downsampled to generate an image pyramid. Subsequently, the spatial distribution of the polarization characteristics of the backscattered light is reconstructed by upsampling, which recovered the clear scene. The proposed method avoids dependence on the background region and is suitable for moving targets with varying polarization properties. The experimental results demonstrate effective elimination of backscattered light while sufficiently preserving the target details. In particular, for dynamic targets, processing times that fulfill practical requirements and yield superior recovery effects are simultaneously obtained.

Ethyl cinnamate suppresses tumor growth through anti-angiogenesis by attenuating VEGFR2 signal pathway in colorectal cancer.

ETHNOPHARMACOLOGICAL RELEVANCE: Kaempferia galanga Linn. is an aromatic medicinal herb with extensively applied in India, China, Malaysia and other South Asia countries for thousands of years. It has been mentioned to treat abdominal tumors. Ethyl cinnamate (EC), one of the main chemical constituents of the rhizome of K. galanga, exhibited nematocidal, sedative and vasorelaxant activities. However, its anti-angiogenic activity, and anti-tumor effect have not been investigated. AIM OF THE STUDY: To investigate the anti-angiogenic mechanism of EC and its anti-tumor effect by suppressing angiogenesis. MATERIALS AND METHODS: The in vitro anti-angiogenic effect was evaluated using HUVECs model induced by VEGF and zebrafish model in vivo. The influence of the EC on phosphorylation of VEGFR2 and its downstream signaling pathways were evaluated by western blotting assay. Molecule docking technology was conducted to explore the interaction between EC and VEGFR2. SPR assay was used for detecting the binding affinity between EC and VEGFR2. To further investigate the molecular mechanism of EC on anti-angiogenesis, VEGFR2 knockdown in HUVECs and examined the influence of the EC. Anti-tumor activity of EC was evaluated using colony formation assay and apoptosis assay. The inhibitory effect of EC on tumor growth was explored using HT29 colon cancer xenograft model. RESULTS: EC obviously inhibited proliferation, migration, invasion and tube formation of VEGF-induced HUVECs. EC also induced apoptosis of HUVECs. Moreover, it inhibited the development of vessel formation in zebrafish. Further investigations demonstrated that EC could suppress the phosphorylation of VEGFR2, and its downstream signaling pathways were altered in VEGF-induced HUVECs. EC formed a hydrogen bond to bind with the ATP binding site of the VEGFR2, and EC-VEGFR2 interaction was shown in SPR assay. The suppressive effect of EC on angiogenesis was abrogated after VEGFR2 knockdown in HUVECs. EC inhibited the colon cancer cells colony formation and induced apoptosis. In addition, EC suppressed tumor growth in colon cancer xenograft model, and no detectable hepatotoxicity and nephrotoxicity. In addition, it inhibited the phosphorylation of VEGFR2, and its downstream signal pathways in tumor. CONCLUSIONS: EC could inhibit tumor growth in colon cancer by suppressing angiogenesis via VEGFR2 signaling pathway, and suggested EC as a promising candidate for colon cancer treatment.

Angular-Momentum Transfer Mediated by a Vibronic-Bound-State.

The notion that phonons can carry pseudo-angular momentum has many major consequences, including topologically protected phonon chirality, Berry curvature of phonon band structure, and the phonon Hall effect. When a phonon is resonantly coupled to an orbital state split by its crystal field environment, a so-called vibronic bound state forms. Here, a vibronic bound state is observed in NaYbSe2 , a quantum spin liquid candidate. In addition, field and polarization dependent Raman microscopy is used to probe an angular momentum transfer of ΔJz = ±â„ between phonons and the crystalline electric field mediated by the vibronic bound stat. This angular momentum transfer between electronic and lattice subsystems provides new pathways for selective optical addressability of phononic angular momentum via electronic ancillary states.

Examining the associations between control (primary and secondary) appraisals and posttraumatic stress disorder symptoms in Malaysian and Australian trauma survivors.

Background: Little research has considered the influence of culture on control appraisals in the context of posttraumatic stress disorder (PTSD). Objectives: This study aimed to investigate whether cultural group moderated the relationship between control (primary and secondary) appraisals and PTSD symptoms in trauma survivors from Western (Australian) and Asian (Malaysian) cultural contexts. Methods: Trauma survivors (107 Australian with European cultural heritage; 121 Malaysian with Malay, Indian or Chinese cultural heritage) completed an online survey assessing PTSD symptoms and appraisals of control. Results: Cultural group moderated the association between primary control and PTSD symptoms; the positive association was significant for the Australian group but not the Malaysian group. While cultural group did not moderate the association between secondary control and PTSD symptoms, there was an indirect pathway between secondary control appraisals and PTSD symptoms through interdependent self-construal for both cultural groups. Conclusion: The findings indicate that cultural group and self-construal influence the associations between different types of control appraisals and PTSD. Further research exploring the role of culture and different appraisal types in PTSD is needed.

Superwavelength self-healing of spoof surface sonic Airy-Talbot waves.

Self-imaging phenomena for nonperiodic waves along a parabolic trajectory encompass both the Talbot effect and the accelerating Airy beams. Beyond the ability to guide waves along a bent trajectory, the self-imaging component offers invaluable advantages to lensless imaging comprising periodic repetition of planar field distributions. In order to circumvent thermoviscous and diffraction effects, we structure subwavelength resonators in an acoustically impenetrable surface supporting spoof surface acoustic waves (SSAWs) to provide highly confined Airy-Talbot effect, extending Talbot distances along the propagation path and compressing subwavelength lobes in the perpendicular direction. From a linear array of loudspeakers, we judiciously control the amplitude and phase of the SSAWs above the structured surface and quantitatively evaluate the self-healing performance of the Airy-Talbot effect by demonstrating how the distinctive scattering patterns remain largely unaffected against superwavelength obstacles. Furthermore, we introduce a new mechanism utilizing subwavelength Airy beam as a coding/decoding degree of freedom for acoustic communication with high information density comprising robust transport of encoded signals.

Experimental Investigation of Vibration Isolator for Large Aperture Electromagnetic MEMS Micromirror.

The Micro-Electro-Mechanical-System (MEMS) micromirror has shown great advantages in Light Detection and Ranging (LiDAR) for autonomous vehicles. The equipment on vehicles is usually exposed to environmental vibration that may degrade or even destroy the flexure of the micromirror for its delicate structure. In this work, a mechanical low-pass filter (LPF) acting as a vibration isolator for a micromirror is proposed. The research starts with the evaluation of vibration influences on the micromirror by theoretical calculation and simulation. The results illustrate that mechanical load concentrates at the slow flexure of the micromirror as it is excited to resonate in second-order mode (named piston mode) in Z-direction vibration. A specific LPF for the micromirror is designed to attenuate the response to high-frequency vibration, especially around piston mode. The material of the LPF is a beryllium-copper alloy, chosen for its outstanding properties of elasticity, ductility, and fatigue resistance. To measure the mechanical load on the micromirror in practical, the on-chip piezoresistive sensor is utilized and a relevant test setup is built to validate the effect of the LPF. Micromirrors with or without the LPF are both tested under 10 g vibration in the Z-direction. The sensor output of the device with the LPF is 35.9 mV in piston mode, while the device without the LPF is 70.42 mV. The attenuation ratio is 0.51. This result demonstrates that the LPF structure can effectively reduce the stress caused by piston mode vibration.

Manipulating the Thermal Conductivity of the Graphene/Poly(vinyl alcohol) Composite via Surface Functionalization: A Multiscale Simulation.

The reverse non-equilibrium molecular dynamics simulation is used to investigate the influence of functional groups (FGs) on the thermal conductivity of a graphene/poly(vinyl alcohol) (PVA) composite, which considers non-polar (methyl) and polar (hydroxyl, amino, and carboxyl) groups. First, the polar groups can be more effective to improve the interfacial thermal conductivity than the non-polar group. This can be explained well by characterizing the interfacial Coulombic energy, number and lifetime of hydrogen bonds, vibrational density of states, and integrated autocorrelation of the interfacial heat power. Moreover, the hydroxyl group can improve the interfacial thermal conductivity more than the other groups, which can be rationalized by analyzing the surface roughness of graphene and the radial distribution function of FGs and the PVA chains. However, the introduction of FGs destroys the graphene structure, which consequently reduces the intrinsic thermal conductivity. Furthermore, by adopting the effective medium approximation model and finite element method, there exists a critical graphene length where the overall thermal conductivities are equal for the functionalized and pristine graphene. Finally, the distribution state of graphene is emphasized to be more vital in determining the overall thermal conductivity than the generally accepted interfacial thermal conductivity.

Underwater active polarization descattering based on a single polarized image.

Active polarization imaging techniques have tremendous potential for a variety of underwater applications. However, multiple polarization images as input are necessary for almost all methods, thereby limiting the range of applicable scenarios. In this paper, via taking full advantage of the polarization feature of target reflective light, the cross-polarized backscatter image is reconstructed via introducing an exponential function for the first time, only based on mapping relations of co-polarized image. Compared with rotating the polarizer, the result performs a more uniform and continuous distribution of grayscale. Furthermore, the relationship of degree of polarization (DOP) between the whole scene and backscattered light is established. This leads to an accurate estimation of backscattered noise and high-contrast restored images. Besides, single-input greatly simplifies the experimental process and upgrades efficiency. Experimental results demonstrate the advancement of the proposed method for objects with high polarization under various turbidities.

Dual-Polarized Multi-Beam Fixed-Frequency Beam Scanning Leaky-Wave Antenna.

A fixed-frequency beam-scanning leaky-wave antenna (LWA) array with three switchable dual-polarized beams is proposed and experimentally demonstrated. The proposed LWA array consists of three groups of spoof surface plasmon polaritons (SPPs) LWAs with different modulation period lengths and a control circuit. Each group of SPPs LWAs can independently control the beam steering at a fixed frequency by loading varactor diodes. The proposed antenna can be configured in both multi-beam mode and single-beam mode, where the multi-beam mode with optional two or three dual-polarized beams. The beam width can be flexibly adjusted from narrow to wide by switching between multi-beam and single-beam states. The prototype of the proposed LWA array is fabricated and measured, and both simulation and experimental results show that the antenna can accomplish a fixed frequency beam scanning at an operating frequency of 3.3 to 3.8 GHz with a maximum scanning range of about 35° in multi-beam mode and about 55° in single-beam mode. It could be a promising candidate for application in the space-air-ground integrated network scenario in satellite communication and future 6G communication systems.

Analyzing and Predicting the Viscosity of Polymer Nanocomposites in the Conditions of Temperature, Shear Rate, and Nanoparticle Loading with Molecular Dynamics Simulations and Machine Learning.

Predicting the viscosity (η) of polymer nanocomposites (PNCs) is of critical importance as it governs a dominant role in PNCs' processing and application. Machine-learning (ML) algorithms, enabled by pre-existing experimental and computational data, have emerged as robust tools for the prediction of quantitative relationships between feature parameters and various physical properties of materials. In this work, we employed nonequilibrium molecular dynamics (NEMD) simulation with ML models to systematically investigate the η of PNCs over a wide range of nanoparticle (NP) loadings (φ), shear rates (γ̇), and temperatures (T). With the increase in γ̇, shear thinning takes place as the value of η decreases on the orders of magnitude. In addition, the φ dependence and T dependence reduce to the extent that it is not visible at high γ̇. The value of η for PNCs is proportional to φ and inversely proportional to T below the intermediate γ̇. Using the obtained NEMD results, four machine-learning models were trained to provide effective predictions for the η. The extreme gradient boosting (XGBoost) model yields the best accuracy in η prediction under complex conditions and is further used to evaluate feature importance. This quantitative structure-property relationship (QSPR) model used physical views to investigate the effect of process parameters, such as T, φ, and γ̇, on the η of PNCs and paves the path for theoretically proposing reasonable parameters for successful processing.