Search Results (238)

Schottky barrier diodes (SBDs) based on low-dimensional materials are of interest for high-speed electronics due to their intrinsic nonlinear transport characteristics. In this work, aligned carbon nanotube Schottky barrier diodes (ACNT-SBDs) were systematically studied through electrical characterization, small-signal modeling, and large-signal nonlinear measurements. Devices with channel widths ranging from 50 to 500 µm were fabricated to examine size-dependent direct-current and high-frequency behavior. Clear Schottky rectification and pronounced geometry-dependent characteristics were observed, with the widest device achieving an intrinsic cutoff frequency of up to 282 GHz. Based on measured S-parameters, a refined small-signal model incorporating a parallel resistance–constant phase element (CPE) branch was developed, providing substantially improved agreement with measured S- and Y-parameters and phase response compared with the classical model. The extracted CPE parameters exhibit systematic dependence on channel width, indicating distributed junction charge dynamics associated with carbon nanotube interfaces. Furthermore, the large-signal nonlinear behavior was evaluated using an anti-parallel diode configuration, achieving a third-harmonic output power of −22.58 dBm at 30 GHz under zero-bias operation. This work provides a comprehensive experimental and modeling framework for understanding the high-frequency and nonlinear behavior of ACNT-SBDs. Full article

High-speed electrical wireline links, spanning Serializer/Deserializer backplanes and cables, chip-to-chip and die-to-die interfaces, wide-parallel single-ended (SE) buses, and simultaneous-bidirectional (SBD) buses, increasingly operate under severe insertion loss, long channel memory, and strong multi-lane interference. Equalization is therefore a central enabler for reliable symbol recovery in the presence of inter-symbol interference (ISI), echo, and near-/far-end crosstalk. This review synthesizes recent principles, architectures, and silicon-proven implementations of wireline equalizers with an emphasis on practical hardware constraints. It further organizes key research trajectories in high-speed wireline communications across three domains: (i) Time-domain equalization and detection for ISI-limited channels, spanning feed-forward equalizers, latency-relaxed decision-feedback equalization architectures that mitigate stringent feedback-loop constraints, and partial-response signaling combined with reduced-complexity maximum-likelihood sequence detection to enhance resilience against extended channel memory. (ii) Advanced modulation and frequency-domain processing, marking the transition from conventional 4-level pulse-amplitude modulation toward higher-order constellations and multicarrier techniques, notably discrete multitone and orthogonal frequency-division multiplexing, which necessitates modulation-aware frequency-domain equalization and adaptive bit- and power-loading algorithms. (iii) Crosstalk and echo mitigation for dense SE and SBD systems, including cancellation filtering in a multiple-input multiple-output framework and coding-aided interference suppression approaches. Across these domains, we present the fundamental trade-offs between equalization performance, algorithmic convergence, power-area efficiency, and latency. Full article

Successful escapes depend on many factors, including predator type and habitat characteristics. Examining escape usually entails directly pursuing an individual and then measuring flight initiation distance (FID), but the effect of prolonged pursuit has not been well studied. We examined escape sequences by blanched adult lesser earless lizards (Holbrookia maculata) in the Salt Basin Dunes (SBDs), testing the hypothesis that escape success and sequences would vary with sex and vegetation use. Their coloration is an adaptation to their sparsely vegetated white sand habitat. To evaluate escape behavior, we followed an individual directly until it disappeared (=successful escape), stopped moving, or 2 min elapsed. We recorded trial habitat (at the start and throughout), time to trial end, FID, length of moves, and total distance moved. FID varied with starting habitat—lizards beginning trials on exposed wood had the longest FID. The sexes differed in their move lengths: females made more short moves, while males made more long moves. The most important plant was sage (Artemisia filifolia), which was occupied at the start of 39% of trials, while 71% of trials ended in sage, and larger sage bushes supported longer escape sequences. Our study highlights the importance of vegetation for refuge and emphasizes the crucial role of the dune-plant landscape to lesser earless lizards. Full article

Millimeter-wave (mmWave)/terahertz (THz) devices relying on conventional semiconductor technologies face significant performance bottlenecks, constraining their use in next-generation electronic systems. To address these challenges, this work demonstrates high-performance THz Schottky barrier diodes (SBDs) based on aligned carbon nanotube (ACNT) arrays, and the realization of a D-band second-harmonic frequency multiplier. The ACNT-SBDs exhibit superior electrical and radio-frequency (RF) characteristics, achieving a forward current density of 0.14 mA·μm⁻¹ at −1.3 V and an intrinsic cutoff frequency (f_C) of 506 GHz. The developed small-signal model of diodes shows close agreement with measurements, with S-parameter relative errors below 0.7% from 100 MHz to 67 GHz. The implemented 154 GHz D-band multiplier achieved a maximum output power of −18.97 dBm and a minimum conversion loss of 27.92 dB, outperforming previously reported frequency multipliers based on carbon nanotubes or two-dimensional (2D) materials. This study not only establishes the outstanding high-frequency response, nonlinear efficiency, and integration potential of ACNT-based devices but also provides a promising technical pathway for future THz communication and sensing applications. Full article

Microwave wireless power transfer (MWPT) technology has the advantages of long distance and high transmission efficiency; therefore, MWPT has many applications in aerospace, space solar power stations (SSPSs), and so on. The receiving and fixing subsystem is the core component for gathering and converting power and it is the main part of the system. If this step is both efficient and possible, the whole system will also be efficient and its success possible. This paper mainly introduces a systematic review of the key technologies, research status, and development trends of the receiving-end part in MWPT. High-performance rectifying devices are analyzed in detail, with the use of GaN Schottky barrier diodes (GaN SBDs), in addition to rectification circuits that have good rectification and impedance matching. Additionally, it compares the advantages and disadvantages of three power synthesis architectures, including RF synthesis, DC synthesis, and hybrid subarray synthesis, and proposes a strategy for optimizing power distribution through intelligent subarray partitioning. Finally, this paper looks at future development trends in receiving-end technology, including miniaturized monolithic microwave integrated circuits (MMICs) and efficient broadband reconfigurable rectification. The research presented herein offers a systematic technical reference and theoretical foundation for enhancing the performance of the receiving ends in microwave wireless power transfer systems. Full article

Biochar application can alter soil properties and enhance soil quality. However, the effects of the regulatory mechanisms underlying nitrogen fertilizer application on soil physicochemical properties and microbial characteristics remain unclear. We conducted a three-year maize field experiment to investigate the effects of four biochar application rates (0, 8, 16, and 24 t/ha) and three nitrogen fertilizer rates (0, 150, and 300 kg/ha) on soil physicochemical properties, enzyme activities, microbial community structure, and maize yield. In the 0–20 cm soil layer, the combined application of biochar and nitrogen fertilizer significantly increased soil porosity (SP) and soil water content (SWC), reduced soil bulk density (SBD), and increased soil organic carbon (SOC) and total nitrogen (TN) levels. Additionally, β-D-cellobiohydrolase and leucine aminopeptidase activities were enhanced, along with nitrogen acquisition potential. The relative abundance of Proteobacteria was highest at a biochar application rate of 16 t/ha. The combined 16 t/ha biochar and 150 kg/ha nitrogen treatment exhibited the highest maize yield. Maize yield was positively correlated with SP, SWC, SOC, and TN. Consequently, the combined application of 16 t/ha biochar and 150 kg/ha nitrogen improved soil physicochemical properties, enhanced soil enzyme activities, regulated key soil microbial taxa, and increased maize yield. Full article

Endometriosis has a significant impact on the social, psychological, psychosomatic, and physical aspects of women’s lives. There is increasing evidence that endometriosis has to be seen as a systemic and complex disorder with a multifactorial etiology, accompanied by numerous other pathologies, such as mental disorders and even cancer. Herein, we analyzed Disability-Adjusted Life Years (DALYs) and Years Lived with Disability (YLDs) generated from the Global Burden of Disease Study (GBD 2021), which are key metrics used to measure the worldwide impact of diseases. Besides, differential gene expression data generated from the Turku Endomet Database were calculated. Briefly, log2-transformed gene expression counts were investigated using linear modeling with the function expression ~ condition to generate log2 fold changes and p-values for each gene. This enabled a precise comparative analysis of mRNA expression levels between control endometrium and various endometriosis-affected tissues, including ovarian endometrioma, peritoneal lesions, and deep endometriosis. Expression patterns of specific genes related to pain and malignant turnover within endometriosis samples and controls have been analyzed. The identification of upregulated genes like FOS, DES, SIRT1, SBDS, SRF, SPN, P2RX1, TEAD3, and SLITRK3, alongside downregulated genes such as KIF22, KIF25, GAS2L2, and HINT3, highlights a broad transcriptional reprogramming within endometriotic tissues. The clustering analysis, which reveals pain-related genes (SRP14/BMF, GDAP1, MLLT10, BSN, and NGF), further solidifies the genetic basis for the chronic and often debilitating pain experienced by patients with endometriosis. In 2021, women with endometriosis experienced the highest rates of total YLDs at 19.98%, with anxiety contributing 17.21% and major depression 8.12%, equating to mean YLDs of 15–24 years. In conclusion, our findings reinforce the need for adopting a holistic, psychosomatic approach to managing endometriosis. The identified genetic markers related to pain provide a biological basis for the profound physical suffering. At the same time, the robust DALYs and YLDs data quantify the devastating impact on mental health, particularly highlighting the significant burden of depression and anxiety. Full article

Urban parks, as vital components of urban green infrastructure, can improve urban ecological environments, showcase urban culture, and offer spaces for human recreation and exercise. However, human activities in these parks also produce severe disruption to soil ecosystems. Studying the effects of recreational disturbances on soil properties and microbial communities is crucial for conserving urban biodiversity and maintaining ecosystem services. This study investigated the effects of human recreational disturbances (HRDs) on soil physicochemical properties and bacterial communities in four forest stands (Phellodendron amurense Rupr (Phe amu), Salix matsudana Koidz. (Sal mat), Pinus tabuliformis var. mukdensis (Pin tab), and Picea asperata Mast. (Pie asp)) in Changchun’s South Lake Park. The results showed that HRD significantly reduced soil water content (SWC) and total phosphorus (TP) while increasing soil bulk density (SBD) and pH. Soil organic carbon (SOC) and total nitrogen (TN) increased in Phe amu and Pie asp soils but decreased in Sal mat and Pin tab soils (p < 0.05). Electrical conductivity (EC) changes were inversely related to SOC and TN trends. Dominant bacterial phyla included Actinobacteriota, Proteobacteria, Acidobacteriota, and Chloroflexi. HRD reduced bacterial species richness and diversity by 5.3% and 7.6%, respectively. SWC and SBD were key factors influencing bacterial community dynamics, with SBD affecting Bacteroidota, Proteobacteria, and Myxococcota, and SWC impacting Proteobacteria, Bacteroidota, and Actinobacteriota. These findings provide insights for urban park management, supporting soil microbial diversity and sustainable urban ecosystem development. Full article

In pursuit of enhancing the performance of power converters, high-frequency power devices have become indispensable due to their superior switching capabilities, reduced conduction loss, and enhanced thermal performance. However, optimizing their efficiency requires a profound comprehension of the interplay between various parameters (the current, voltage, and gate resistance) on switching dynamics and power losses. This study presents a comprehensive framework of loss characterization with multi-parametric variations. The influence of drain-source current $\left(I_{ds}\right)$, DC voltage $\left(V_{dc}\right)$, and gate resistor $\left(R_g\right)$ on switching and conduction losses are explicitly quantified. A significant contribution of this study lies in the comprehensive analytical and empirical characterization of the turn-on and turn-off power dissipation dynamics in SiC MOSFETs, emphasizing the intricate interplay between parameters and efficiency. Conventional studies primarily focus on empirical loss characterization, yet this work advances the field by introducing a predictive loss model that systematically correlates $R_g$, $I_{ds}$, and $V_{dc}$ variations with induced switching dynamics, and EMI mitigation strategies. Increasing $R_g$ effectively suppresses voltage overshoots and mitigates ringing effects, concurrently prolonging switching events, thereby broadening the power dissipation profile and influencing system-level performance. Furthermore, this study rigorously evaluates the commutation behavior of the SiC MOSFET/SBD pair, providing an in-depth examination of its dynamic loss characterization under varying conditions. This novel insight establishes a crucial framework for efficiency drive optimization. Full article

This review provides a comprehensive overview of the fundamental aspects of nanoparticles (NPs), emphasizing their physicochemical properties and biological interactions, with particular focus on porous silica nanoparticles (PSNs). The review provides information on the Safe-by-design (SbD) S.A.F.E. (Standardised characterization, Assessment of biocompatibility, Facilitation of toxicity and exposure routes and Evaluation of clinical translation) framework. It discusses critical factors influencing NP toxicity and cellular uptake, including particle size, shape, pore size, surface charge, surface functionalisation, and crystallinity. The review also examines exposure routes of NPs—inhalation, dermal, oral, systemic and mucosal—and their subsequent biological effects. A key section is dedicated to the formation of the protein corona, a critical determinant of NP fate in biological systems, and its influence on circulation time, immune clearance and cellular responses. Particular attention is given to assessing the biological interactions of the PSNs and the mechanisms underlying PSN-induced cytotoxicity and genotoxicity, with a focus on the assays commonly employed to evaluate these effects. The review explores the use of gene expression profiling as a powerful tool to elucidate the molecular mechanisms underlying nanoparticle-induced cellular changes. This review aims to provide an integrated perspective on the SbD considerations and safety implications of nanomaterials. It highlights the need for a deeper understanding of complex biological interactions to establish SbD principles and enable the translation of PSNs into clinical applications. Finally, current regulatory frameworks and guidelines for testing nanomaterials, including PSNs, that support their safe and sustainable development are discussed. Full article

The precise ranging of ultra-wideband (UWB) fuzes relies on extracting time delay information from echo signals. However, ground multipath propagation effects induce a significant time-delay spread in the echo signals. This manifests as a channel impulse response (CIR) composed of numerous, closely spaced components, creating a challenging super-resolution problem that severely constrains the ranging accuracy and reliability of the fuze. Therefore, accurately estimating the CIR that characterizes these multipath structures from a single echo observation is crucial for the UWB fuze to perceive terrain structures and enhance ranging capabilities. This study proposes the following methods: (1) establishing an equivalent discrete multipath model(EDMM) of the ground to characterize the CIR; (2) proposing a sparse blind deconvolution(SBD) method via the ADMM-based framework under an asymmetric structured prior (ASP), which employs parametric projections to constrain the physical morphology of the unknown source signal, and designing a periodic sparse cluster projection operator to achieve super-resolution recovery of the discrete multipath structure of the channel h by enforcing the EDMM prior. Through three-variable robust decomposition, it actively separates dispersed clutter and enhances performance under low signal-to-noise ratio (SNR) conditions. Experimental results from both simulations and measured data demonstrate that the proposed algorithm exhibits excellent robustness and recovery accuracy in complex low-SNR scenarios, providing a foundational offline analysis method for understanding complex channel characteristics and guiding the development of improved real-time ranging algorithms. Full article

Thanks to its excellent material properties, diamond-based power electronic devices have garnered widespread attention. The realization of large-sized (over 2 inches) and high-quality single-crystal diamond wafers has significantly accelerated the industrialization of diamond semiconductor materials and devices. Over years of development, diamond Schottky barrier diodes (SBDs) have evolved into three primary device structures: lateral conduction type, quasi-vertical conduction type, and vertical conduction type. However, the performance of these devices has yet to fully unlock the potential of diamond materials. Efficient edge termination structures need to be designed to synergistically optimize the forward turn-on voltage, on-resistance, and off-state breakdown voltage. This paper reviews the research progress on various existing edge termination structures of diamond SBDs, analyzes the advantages of each structure, and discusses the key challenges faced in the device fabrication processes. Full article

Background: Aerobic and resistance training have acute effects on blood pressure (BP) in peripheral arterial disease (PAD). However, the combined effect of both exercises in a single session is still unknown. The aim of this study was to analyze the effects of a single exercise session combining walking and circuit-based training on BP in patients with PAD. Methods: Participants with PAD (n = 13; 65.0 ± 10.2 years; 76.9% male) underwent a supervised exercise therapy (SET) intervention (312 sessions, 24 sessions/patient) that included 15–30 min of walking, followed by 15 min circuit-based training. Clinic systolic (SBP) and diastolic (DBP) were recorded 5 min before and after each exercise session. Longitudinal changes were analyzed using repeated-measures analysis of variance (ANOVA) and categorical changes in blood pressure levels were evaluated with chi-square tests. Results: After each exercise session, clinic SBP decreased 4.87 mmHg (p < 0.001) and clinic DBP decreased 2.11 mmHg (p < 0.001). Furthermore, there were no differences between the initial stage of training (1–10 sessions) and late (14–24 sessions) for each time that SBD or DBP were measured. Conclusions: After an acute exercise session, both clinical SBP and DBP decreased in patients with PAD compared to pre-exercise values. However, no additional reductions in clinical BP were observed when comparing early (sessions 1–10) and late (sessions 14–24) stages of the full SET intervention. Full article

Accurately recognizing student classroom behaviors is essential for analyzing teacher–student interactions and enabling intelligent educational assessment. Although deep learning offers promising solutions, existing methods often perform poorly in complex classroom environments due to occlusions and subtle, overlapping actions. To address these issues, this article proposes a robust and efficient method for behavior recognition by enhancing the You Only Look Once version 8 (YOLOv8) architecture with a Multi-Head Self-Attention (MHSA) module, termed YOLOv8-MHSA. The integration of MHSA allows the model to capture contextual relationships between distant spatial features, which is critical for distinguishing similar behaviors. For a comprehensive evaluation, we also implement a model with Coordinate Attention (CA). Experimental results on a standard dataset demonstrate the superiority of our YOLOv8-MHSA model, which achieves a precision of 0.86, recall of 0.807, mAP50 of 0.855, and mAP50-95 of 0.677, delivering competitive performance compared to the state-of-the-art SBD-Net. These findings validate that explicit contextual modeling via self-attention significantly boosts performance in fine-grained behavior recognition. Consequently, this research has direct potential applications in providing automated, data-driven tools for teacher training, classroom quality assessment, and, ultimately, supporting the development of personalized education systems. Full article