We present an experimental study of proton acceleration driven by femtosecond multi-PW lasers of three different prepulse parameters with the peak laser intensity of 1.2 × 1021 W/cm2 irradiating micrometre-thick metal foils. For 4-μm-thick copper foils, the highest-energy proton beam of 58.9 MeV is generated with the moderate-contrast laser, while the low-contrast or high-contrast lasers result in the lower proton cutoff energies. The one-dimensional hydrodynamic and two-dimensional particle-in-cell simulations indicate that the front preplasma of foils induced by the laser prepulse can enhance electron acceleration and in turn improve proton acceleration, while the rear preplasma will weaken the sheath field and be unfavourable for accelerating ions. For the case of the moderate contrast, the scale length of the front preplasma is long enough to generate high-temperature electrons compared to the high-contrast case, and the scale length of the rear preplasma is so short that the sheath field still remains strong compared with the low-contrast case, which is advantageous for generating high-energy protons. Meanwhile, a concrete map is theoretically given for accelerating higher-energy protons. This work extends the concept of the prepulse effect on target normal sheath acceleration (TNSA) to a wider range of laser parameters (multi-PW, 1021 W/cm2), representing an important step towards potential applications of TNSA-driven proton sources, especially considering that PW and even 10 PW laser facilities exist all around the world.

The dual-tone transition phenomenon and its formation mechanism in the flow around a heptagonal cylinder (side number $N= 7$) are experimentally investigated in depth over a range of free-stream velocities corresponding to Reynolds numbers of the order of $10^4$–$10^5$. Dual tone in this context refers to the emergence of two dominant peaks in the far-field acoustic spectrum when a flow in transition regime passes over a polygonal cylinder in principal orientations. The dual-tone phenomenon is also observed in an $N = 9$ cylinder in the face orientation and an $N = 11$ in the corner orientation, which contrasts with all the other polygonal cylinders of $N\in {\mathbb{Z}}[3,12]$ systematically investigated in the present study, where only a single tonal peak dominates the spectrum, similar to the Aeolian tone observed in the circular cylinder in the subcritical regime. The emergence of the dual tone is found to be responsible for the reduction of far-field noise. Continuous wavelet transform analysis reveals that the occurrence of the two competing tones in the time domain can be empirically modelled by Gaussian distributions. Additional proper orthogonal decomposition based phase averaging using time-resolved planar particle image velocimetry enables coherent vortex structure identification for the two quasi-stable shedding modes, which are responsible for the formation of the two tones. Near-wall flow and pressure fluctuation analysis further confirms that the two tones originate from stochastic shear-layer separation–reattachment switching, thereby generating two patterns of dipole sound sources through distinct vortex formation pathways.

In this paper, we numerically investigate the orbit dynamics of three-dimensional symmetric Janus drops in shear flow using an improved ternary-fluids phase field method, focusing on how drop deformation and initial orientation affect the orbit drift of two configurations of Janus drops: dumbbell-shaped and near-spherical. We find that the motion of dumbbell-shaped drops eventually evolves into tumbling, while near-spherical drops attain stable spinning. We attribute this bifurcation in orbit drift to contrasting deformation dynamics and shape-dependent hydrodynamics of the two configurations. Specifically, the drift bifurcation is closely related to the aspect ratio of Janus drops at equilibrium, giving rise to two distinct mechanisms: (1) coupling between outer interface deformation and the surrounding flow field; and (2) interplay between inner interface deformation and vortices enclosed within the drop. In addition, we observe that for the dumbbell-shaped Janus drops with different aspect ratios, their tumbling dynamics resembles ellipsoids in shear flow. Moreover, the trajectories of the dumbbell-shaped Janus drops during orbit drift collapse onto a universal curve, independent of their initial orientations, and significant deformation and inertia accelerate the orbit transition. To quantitatively evaluate the effect of drop deformation on the orbit drift of the dumbbell-shaped Janus drops, we propose an effective aspect ratio model based on the drop shapes at equilibrium and at the maximum elongation. By incorporating the effective aspect ratio into Jeffery’s theory for solid particles, we accurately predict the rotation period and angular velocity of Janus drops in the tumbling regime and during the orbit drift, especially for drops with linear deformation. Moreover, the orbit parameter $C$ is found to vary exponentially with time for drops with linear deformation, while the time variation of $C$ transits from one exponential function to another for drops with nonlinear deformation.

Aerothermal issues in hypersonic transitional swept shock wave/boundary-layer interactions (SBLIs) are critical for the structural safety of high-speed vehicles but remain poorly understood. In this work, previously scarce, high-resolution heat transfer distributions of the hypersonic transitional swept SBLIs, are obtained from fast-responding temperature-sensitive paint (fast TSP) measurements. A series of $34^\circ$ compression ramps with sweep angles ranging from $0^\circ$ to $45^\circ$ are tested in a Mach 12.1 shock tunnel, with a unit Reynolds number of 3.0 $\times$ 10$^{6}$ m$^{-1}$. The fast TSP provides a global view of the three-dimensional aerothermal effects on the ramps, allowing in-depth analysis on the sweep effects and the symmetry of heat transfer. The time-averaged results reveal that the heat flux peak near reattachment shifts upstream with decreasing amplitude as the sweep angle increases, and a second peak emerges in the $45^\circ$ swept ramp due to a type V shock–shock interaction. Downstream of reattachment, the heat flux streaks induced by Görtler-like vortices weaken with increasing sweep angle, whereas their dominant projected wavelengths show little dependence on sweep angle or spanwise location. Away from the ramp’s leading side, the transition onset of the reattached boundary layer gradually approaches the reattachment point. Finally, a general quasi-conical aerothermal symmetry is identified upstream of reattachment, although spanwise variations in transition onset, shock–shock interaction and heat flux streaks are found to disrupt this symmetry downstream of reattachment with varying degrees.

Computer vision–based precision weed control has proven effective in reducing herbicide usage, lowering weed management costs, and enhancing sustainability in modern agriculture. However, developing deep learning models remains challenging due to the effort required for weed dataset annotation and the difficulty of identifying weeds at different stages and densities in complex field conditions. To address these challenges, this study introduces an indirect weed detection method that combines deep learning and image processing techniques. The proposed approach first employs an object detection network to identify and label crops within the images. Subsequently, image processing techniques are applied to segment the remaining green pixels, thereby enabling indirect detection of weeds. Furthermore, a novel detection network—CD-YOLOv10n (You Only Look Once version 10 nano)—was developed based on the YOLOv10 framework to optimize computational efficiency. Redesigning the backbone (C2f-DBB) and integrating an optimized upsampling module (DySample) permitted the network to achieve higher detection accuracy while maintaining a lightweight structure. Specifically, the model achieved a mean average precision (mAP50) of 98.1%, which is a 1.4% percentage-point increase compared with the YOLOv10n baseline, a relevant improvement given the already strong baseline performance. At the same time, compared with YOLOv10n, its GFLOPs (giga floating-point operations per second) were reduced by 22.62%, and the number of parameters decreased by 15.87%. These innovations make CD-YOLOv10n highly suitable for deployment on resource-constrained platforms.

Entrepreneurial reentry after business failure is an important area of research in the field of entrepreneurship. However, previous studies have largely overlooked the crucial role of time factors – both objective and subjective – in the context of failure and subsequent entrepreneurial endeavors. This study aims to fill this gap by examining the impact of firm lifespan on entrepreneurial reentry and the moderating effect of entrepreneurs’ temporal focus. Through manual matching across multiple databases, we obtain a sample of 368 entrepreneurs. The results show that a longer firm lifespan negatively influences entrepreneurial reentry and that a past focus further amplifies this negative relationship. This study contributes to research on the determinants of entrepreneurial reentry and provides theoretical insights into the role of time in entrepreneurial reentry.

Non-suicidal self-injury (NSSI) among adolescents severely jeopardizes their well-being and has emerged as a significant global public health challenge. However, research on the trends in NSSI among adolescents remains scarce. This study sought to uncover the evolving patterns in the severity of NSSI among adolescents and the factors that influence these patterns. The Deliberate Self-Harm Inventory was employed to measure the severity of NSSI among adolescents. Relevant studies were retrieved from both Chinese databases (CNKI, Wanfang, and VIP) and English databases (Web of Science, PubMed, Scopus, ProQuest, and Wiley). A total of 70 articles (71 studies; N = 96,382) were included in this review. The data spanned from 2007 to 2023. The analysis revealed the following: (1) Although the severity of NSSI showed a small to moderate upward trend from 2007 to 2023, this increase did not reach statistical significance. (2) No significant differences in trends were observed among Asia, Europe, and the America. (3) Adolescents with clinical samples exhibited a more pronounced upward trajectory in NSSI severity compared to those with non-clinical samples. (4) Social development indicators (GDP per capita, Human Development Index, and Internet penetration rate) and social well-being (happiness index) exhibited significant positive correlations with NSSI among adolescents. Conversely, lower social equity (higher Gini coefficient) was associated with reduced NSSI among adolescents. This study elucidated the changing trends in NSSI among adolescents and offered novel insights for the early prevention and individualized intervention of NSSI among adolescents.

In dynamic environments, moving objects pose a great challenge to the accuracy and robustness of visual simultaneous localization and mapping (VSLAM) systems. Traditional dynamic VSLAM methods rely on hand-designed feature frames, and these methods usually make it difficult to fully utilize feature information in dynamic regions. To this end, this paper proposes a SLAM system (GAF-SLAM) that combines gray area feature points, weighted static probabilities, and spatio-temporal constraints. This method realizes the efficient fusion of key point detection and target detection by introducing YOLO-Point to extract gray area feature points from dynamic regions. These feature points are located within the detection frame and have potentially static feature point properties. By combining the reprojection error and polar geometry constraints, potential static feature points are effectively screened out and the identification of these gray area feature points is further optimized. Subsequently, a novel static probabilistic computational framework is designed to assign weights to these gray area feature points and dynamically adjust their influence on the optimization results during the attitude estimation process. By combining static probability with temporal continuity and spatial smoothness constraints, the system achieves significantly improved localization accuracy and robustness in dynamic environments. Finally, the proposed method was evaluated on the TUM RGB-D dataset. The experimental results demonstrate that GAF-SLAM significantly improves pose estimation accuracy and exhibits strong robustness and stability in dynamic indoor environments.

Spectral coherent combining (SCC) offers a powerful approach to increase output power and shorten pulse duration. Here, we comprehensively investigate SCC of two beams to achieve the high combining performance. The preliminary analysis indicates that incident spectra and the transition region of the combiner both affect the combining process. The simulation results show that optimizing the overlapping spectral range, the transition width and start wavelength of the combiner can achieve high combining efficiency and high pulse quality. Guided by the simulation results, we built a femtosecond laser system based on the SCC of two fiber amplifiers, achieving 96.9% combining efficiency and high-quality 42-fs pulses. To the best of our knowledge, this is the first time that high combining efficiency and high pulse quality have been achieved simultaneously in a fiber femtosecond laser system based on SCC. This study provides design guidelines for the high-performance combination of beams covering different spectral regions.

Biomechanical intervention on lower limb joints using exoskeletons to reduce joint loads and provide walking assistance has become a research hotspot in the fields of rehabilitation and elderly care. To address the challenges of human-exoskeleton (H-E) kinematic compatibility and knee joint unloading demands, this study proposes a novel rhombus linkage exoskeleton mechanism capable of adaptive knee motion without requiring precise alignment with the human knee axis. The exoskeleton is driven by a Bowden cable system to provide thigh support, thereby achieving effective knee joint unloading. Based on the screw theory, the degrees of freedom (DOF) of the exoskeleton mechanism (DOF = 3) and the H-E closed-loop mechanism (DOF = 1) were analyzed, and the kinematic model of the exoskeleton and the H-E closed-loop kinematic model were established, respectively. A mechanical model of the driving system was developed, and a simulation was conducted to validate the accuracy of the model. The output characteristics of the cable-driven system were investigated under varying bending angles and bending times. A prototype was fabricated and tested in wearable scenarios. The experimental results demonstrate that the exoskeleton system exhibits excellent biocompatibility and weight-bearing support capability. Compatibility tests confirm that the exoskeleton does not interfere with human motion. Through human-in-the-loop optimization, the optimal Bowden cable output force profile was obtained, which minimizes gait impact while achieving a peak support force of 195.8 N. Further validation from wear trials with five subjects confirms the system’s low interference with natural human motion (maximum lower-limb joint angle deviation of only $8^\circ$).

Introduction: We propose to develop a Unique Device Identification (UDI) barcode tracking system for surgical instruments. This system aims to enhance hospital processes, thereby benefiting both patients and staff members. Methods: The UDI barcode tracking system for surgical instruments was implemented in March 2023: 1. Each surgical instrument underwent laser engraving with a UDI barcode, encompassing relevant data such as instrument name, image, model, specifications, origin, license, Instructions for Use (IFU), and total distribution quantity. 2. Upon scanning the engraved serial number, the system automatically discerns whether the instrument belongs to the designated set. 3. Mechanical, chemical, and biological monitoring indicators are integrated into the tracking system, with automatic adjudication for release into storage if criteria are met; otherwise, notifications are issued for review and retrieval by personnel. Results: 1. Between March 2023 and February 2024, a total of 157,614 instrument sets were equipped with this system, enabling staff to achieve a zero-error rate in rapid and precise instrument identification. 2.During this period, 4,026 cycles of high-temperature sterilization monitoring and 380 cycles of low- temperature H2O2 plasma sterilization monitoring were recorded. 3.Each monitoring cycle was digitally recorded, obviating the necessity for paper-based documentation and saving a total of 4,406 A4 paper sheets. 4. In the same timeframe, a total of 85,899 packages were dispensed, each linked to patient medical record numbers. Conclusions: The adoption of the surgical instrument UDI barcode tracking system by our institution’s central sterilization supply department has garnered participation from 622 individuals. It not only reduces the time spent by staff searching for items and conducting educational training but also automatically identifies whether the instrument belongs to the package, thereby enhancing inventory efficiency and reducing the incidence of errors. Sterilization monitoring indicators are automatically uploaded and intercepted to uphold patient safety.

Tuta absoluta has evolved resistance to many biological insecticides, resulting in significant annual agricultural and economic losses. Glutathione S-transferases (GSTs) are one of the major insect detoxification enzyme systems. However, the detoxification metabolism of GSTs in T. absoluta against biological insecticides remains poorly understood. In this study, We identified five key GST genes (TaGSTs1, TaGSTs2, TaGSTe1, TaGSTe3, and TaGSTd1) by screening from the comparative transcriptomes of two regional populations of T. absoluta in Xinjiang, China. Among the five GSTs, TaGSTs1 exhibited a significantly high expression level during the larval stage of T. absoluta following exposure to the LC50 dose of spinetoram. This gene was subsequently cloned, and its expression was knocked down using RNA interference to further analyse its role in the detoxification of spinetoram, as well as in the growth and development of T. absoluta. The results showed that TaGSTs1 contains a typical GST gene domain and was highly conserved within the Lepidoptera clade. Silencing of the TaGSTs1 gene led to a significant increase in the susceptibility of T. absoluta to spinetoram, as evidenced by an extension in the duration of leaf-mining and in the development time from the 2nd to the 4th instar larval stage, which were 35.7% and 19.6% longer, respectively, than those of ddH2O and dsGFP controls. Furthermore, the mortality rate of larvae treated with dsTaGSTs1 reached 57.3% by the 7th day. These findings indicate that TaGSTs1 plays a crucial role in the detoxification of spinetoram and in the growth and development of T. absoluta larvae.

Seasonal changes and cyclical human activities (such as periodic fishing bans, Wolbachia-based mosquito population control, and school term breaks) have significant impacts on population dynamics. We propose a general switching dynamical model to describe these periodic changes. The existence, uniqueness and stability of positive periodic solutions are thoroughly investigated. The results are stated in terms of an introduced threshold value. To demonstrate their practicability, the obtained results are applied to two biological situations.