Compressibility transformations have received considerable attention for extending well-established incompressible wall models to high-speed flows. While encouraging progress has been made in mean velocity scalings, research on temperature transformations has lagged behind. In this study, we rigorously derive a general framework for both velocity and temperature transformations directly from the compressible Reynolds-averaged Navier–Stokes (RANS) equations and their ‘incompressible’ counterparts, elucidating how these transformations guide the development of compressible algebraic RANS models in the inner layer. The introduction of the mixed Prandtl number further links the mean momentum and energy transport, facilitating the formulation of novel temperature transformations through integration with arbitrary mean velocity scalings, thereby unifying existing transformation methods while providing a systematic approach for further improvement. A detailed evaluation using direct numerical simulation databases of canonical compressible wall-bounded turbulent flows (CWBTFs) demonstrates that temperature transformations based on the Griffin–Fu–Moin and our recently proposed velocity scalings exhibit superior accuracy and robustness across a wide range of Reynolds and Mach numbers, as well as varying wall thermal boundary conditions. We also perform a preliminary investigation into the applicability of the proposed integral mean temperature–velocity relation and inverse temperature transformations for near-wall temperature modelling in cold-wall boundary layer flows, where discontinuities caused by non-monotonic temperature distributions are effectively avoided. Although the omission of higher-order terms in deriving the total heat flux equation enables closed-form wall modelling, it remains a key limitation to the model’s accuracy at the current stage. Future work may therefore need to address this issue to achieve further advances. These findings enhance the physical understanding of mean momentum and energy transport in canonical CWBTFs, and offer promising prospects for advancing near-wall temperature modelling within RANS and wall-modelled large eddy simulation frameworks.

Most exoskeletons are designed with the shoulder joint’s instantaneous center of rotation (ICR) in mind as a fixed joint, often also known as the center of the shoulder joint. In fact, shoulder ICR changes during shoulder abduction–adduction and flexion–extension. Abduction–adduction causes the ICR to move in the frontal plane, which is caused by the joint movement of the shoulder joint, including depressed elevation and horizontal translation, while the flexion–extension movement of the sagittal plane produces the shoulder extension movement. If the change in shoulder ICoR movements is not compensated for in the exoskeleton design, they can create discomfort and pain for the robot’s wearer. Although conventional exoskeletons typically treat the shoulder joint as a three degree of freedom spherical joint, this study incorporates a more sophisticated understanding of shoulder kinematics. The developed scapulohumeral rhythm compensation mechanism successfully compensates for shoulder joint motion, with simulation results confirming kinematics that closely match ergonomic shoulder movement patterns. First, the complex kinematics of the shoulder joint are analyzed. To meet the demand for mismatch compensation, a shoulder exoskeleton based on a winding mechanism is designed. A mismatch compensation model is established, and theoretical analysis and simulation verify that the designed shoulder exoskeleton has a mismatch compensation function. While solving the mismatch problem, the human–machine coupling model is established through OpenSim software. The simulation results show that the designed exoskeleton has a good assisting effect from the perspective of muscle force generation and shoulder torque.

In this study, changes in physiological characteristics of Coridius chinensis (Hemiptera: Dinidoridae) during diapause and post-diapause development period were determined. The moisture content of C. chinensis at the beginning of diapause was significantly lower than that at any other stage, and the moisture content during post-diapause development period was significantly higher than that from October to December 2021 and in February and April of the following year. The fat content gradually declined over time. The glycogen content remained at lower levels during diapause but rose sharply during the post-diapause development period, when it became significantly higher than that during diapause. The trehalose content gradually declined in the early stages of diapause but rose greatly in the middle stage, followed by a gradual decline in the late stages and a significant increase during the post-diapause development period. The protein content was at lower levels in the early stages of diapause, significantly lower than that in the middle and late stages of diapause and that during post-diapause development period. The results indicated significant differences in changes in the moisture, fat, carbohydrate, and protein contents between the diapause and post-diapause development periods, with obvious stage characteristics. This study provides a scientific basis for further research on the diapause physiology of C. chinensis.

Capturing dynamic targets is particularly challenging for either rigid or soft grippers, as impact buffering should be completed in a short time to ensure the reliability of the robotic system. At collision onset, to deal with relatively low contact forces, adopting low stiffness and damping can effectively mitigate the rebound of the dynamic targets. As the contact area and forces increase, employing high stiffness and damping becomes necessary for absorbing high energy. This paper proposed a novel robotic gripper whose stiffness and damping follow a predefined profile “low stiffness and damping for low impact and high stiffness and damping for high impact.” The variable effects of impact buffering and energy dissipation in a collision process were modeled and analyzed. Then, a passive variable stiffness and damping regulator (P-VSDR) was developed where tendons and pulleys are used to generate a nonlinear motion from a linear spring-damper unit. The contact dynamics model of the robotic gripper equipped with P-VSDR was established. Simulated and experimental results show that this gripper enables reliable capture of dynamic targets with different velocities.

A species of acanthocephalan collected from the hindgut of Larimichthys crocea was identified as Longicollum pagrosomi Yamaguti, 1935 based on morphological characteristics. The complete mitochondrial genome of this parasite was sequenced. The mitogenome exhibited a circular structure with a total length of 14 632 bp, containing 12 protein coding genes (PCGs), 2 ribosomal RNAs (rRNAs), 22 transfer RNAs (tRNAs) and 2 major non-coding regions. The most frequently used start codon was GTG, and the most abundant amino acid was valine. The phylogenetic analyses of the mitogenome using Bayesian inference and maximum likelihood methods showed that the genus Longicollum formed a sister clade to the genus Pomphorhynchus, supporting the monophyly of Pomphorhynchus. This study reported a new host for L. pagrosomi and revealed the first complete mitogenome sequence of the genus Longicollum.

Ultra-thin liquid sheets generated by impinging two liquid jets are crucial high-repetition-rate targets for laser ion acceleration and ultra-fast physics, and serve widely as barrier-free samples for structural biochemistry. The impact of liquid viscosity on sheet thickness should be comprehended fully to exploit its potential. Here, we demonstrate experimentally that viscosity significantly influences thickness distribution, while surface tension primarily governs shape. We propose a thickness model based on momentum exchange and mass transport within the radial flow, which agrees well with the experiments. These results provide deeper insights into the behaviour of liquid sheets and enable accurate thickness control for various applications, including atomization nozzles and laser-driven particle sources.

This paper presents a general approach to synthesizing closed-loop robots for machining and manufacturing of complex quadric surfaces, such as toruses, helicoids, and helical tubes. The proposed approach begins by employing finite screw theory to describe the motion sets generated by prismatic, rotational, and helical joints. Subsequently, generatrices and generating lines are put forward and combined for type synthesis of serial kinematic limbs capable of generating single-DoF translations along spatial curves and two-DoF translations on complex quadric surfaces. Following this manner, the two-DoF translational motion patterns on these complex quadric surfaces are algebraically defined and expressed as finite screw sets. Type synthesis of close-loop robots having the newly defined motion patterns can thus be carried out based upon analytical computations of finite screws. As application of the presented approach, closed-loop robots for machining toruses are synthesized, resulting in four-DoF and five-DoF standard and derived limbs together with their corresponding assembly conditions. Additionally, brief descriptions of robots for machining helicoids and helical tubes are provided, along with a comprehensive list of all the feasible limbs for these kinds of robots. The robots synthesized in this paper have promised applications in machining and manufacturing of spatial curves and surfaces, enabling precise control of machining trajectories ensured by mechanism structures and achieving high precision with low cost.

This paper introduces a distributed online learning coverage control algorithm based on sparse Gaussian process regression for addressing the problem of multi-robot area coverage and source localization in unknown environments. Considering the limitations of traditional Gaussian process regression in handling large datasets, this study employs multiple robots to explore the task area to gather environmental information and approximate the posterior distribution of the model using variational free energy methods, which serves as the input for the centroid Voronoi tessellation algorithm. Additionally, taking into consideration the localization errors, and the impact of obstacles, buffer factors and centroid Voronoi tessellation algorithms with separating hyperplanes are introduced for dynamic robot task area planning, ultimately achieving autonomous online decision-making and optimal coverage. Simulation results demonstrate that the proposed algorithm ensures the safety of multi-robot formations, exhibits higher iteration speed, and improves source localization accuracy, highlighting the effectiveness of model enhancements.

Glyphodes pyloalis Walker (Lepidoptera: Pyralidae) is a destructive monophagous pest of mulberry, Morus Linnaeus (Moraceae), trees. In order to identify mulberry cultivars resistant to G. pyloalis, 12 cultivars were examined using field and in vitro testing. Field observations indicated that cultivars AlbapC, BombyL, LaeviT, and CathaB had less than 10.0% damage, with no observed damage on the CathaB cultivar. The life table parameters showed that CathaB cultivar had the longest larval and pupal duration (23.2 days in total), the shortest adult period (5.3 days), the lowest rates of both pupation (55.0%) and adult emergence (69.7%), the highest adult mortality (61.7%), the lowest average weight of pupae (30.4 mg), and the lowest daily oviposition (5.0 eggs/female/day). The larval performance of G. pyloalis in the field revealed that CathaB had the lowest larval density. Correlation analyses confirmed that significant correlations exist between all the performance parameters of G. pyloalis for both the observed damage and larval performance. Leaf characterisation of selected cultivars indicated CathaB had significantly higher values of leaf wax, trichome density, soluble glucose, and protein contents compared to MultiQ. This study would be a valuable reference for evaluating pest-resistant cultivars and establishing a theoretical foundation for managing G. pyloalis.

Deformation occurs in a thin liquid film when it is subjected to a non-uniform electric field, which is referred to as the electrohydrodynamic patterning. Due to the development of a non-uniform electrical force along the surface, the film would evolve into microstructures/nanostructures. In this work, a linear and a nonlinear model are proposed to thoroughly investigate the steady state (i.e. equilibrium state) of the electrohydrodynamic deformation of thin liquid film. It is found that the deformation is closely dependent on the electric Bond number BoE. Interestingly, when BoE is larger than a critical value, the film would be deformed remarkably and get in contact with the top template. To model the ‘contact’ between the liquid film and the solid template, the disjoining pressure is incorporated into the numerical model. From the nonlinear numerical model, a hysteresis deformation is revealed, i.e. the film may have different equilibrium states depending on whether the voltage is increased or decreased. To analyse the stability of these multiple equilibrium states, the Lyapunov functional is employed to characterise the system’s free energy. According to the Lyapunov functional analysis, at most three equilibrium states can be formed. Among them, one is stable, another is metastable and the third one is unstable. Finally, the model is extended to study the three-dimensional deformation of the electrohydrodynamic patterning.

The attachment-line boundary layer is critical in hypersonic flows because of its significant impact on heat transfer and aerodynamic performance. In this study, high-fidelity numerical simulations are conducted to analyse the subcritical roughness-induced laminar–turbulent transition at the leading-edge attachment-line boundary layer of a blunt swept body under hypersonic conditions. This simulation represents a significant advancement by successfully reproducing the complete leading-edge contamination process induced by a surface roughness element in a realistic configuration, thereby providing previously unattainable insights. Two roughness elements of different heights are examined. For the lower-height roughness element, additional unsteady perturbations are required to trigger a transition in the wake, suggesting that the flow field around the roughness element acts as a perturbation amplifier for upstream perturbations. Conversely, a higher roughness element can independently induce the transition. A low-frequency absolute instability is detected behind the roughness, leading to the formation of streaks. The secondary instabilities of these streaks are identified as the direct cause of the final transition.

Objectives/Goals: In mice, it has been shown that loss of Cib2 (calcium and integrin-binding protein 2) results in progressive retinal disease that recapitulates many characteristics of age-related macular degeneration (AMD). This study aims to characterize transcriptional changes in the retinal pigment epithelium (RPE) that underlie this disease process. Methods/Study Population: RPE tissue samples, pooled from 2–3 mice for each biological group, were collected from Cib2-KO and wildtype (WT) mice at two (young) and eight (aged) months of age. Bulk mRNA sequencing was performed using the Illumina HiSeq 4000. Reads were aligned to the UCSC mouse reference genome and quantified using HTSeq. Significant differentially expressed genes (DEGs) between mouse genotype and age groups were assessed using DESeq. CLICK unsupervised clustering followed by gene ontology analysis was performed to identify cellular processes and molecular pathways affected by loss of Cib2 as well as age. Results/Anticipated Results: CLICK analysis revealed several functional pathways that are differentially expressed between sample groups. For example, in both young and aged mice, pathways upregulated in Cib2-KO samples included calcium signaling, RhoA signaling, and integrin signaling. Uniquely downregulated DEGs in young Cib2-KO animals were related to complement and coagulation cascades, LXR/RXR activation (related to lipid synthesis and transport), and phagosomes. Aged Cib2-KO mice displayed the most significant downregulation of genes in the phototransduction pathway, indicating temporal changes in functional pathways that correlate with disease progression. Next steps in analysis include investigating patterns in RPE- and AMD-signature gene sets that may identify molecular pathways more specific to human disease. Discussion/Significance of Impact: Many current studies investigate the role of complement activation, vesicle trafficking, and ion transport as top contributors to AMD development. We identified DEGs paralleling many of these molecular pathways in Cib2-KO mice, highlighting their potential as a model to study age-related RPE pathologies and evaluate therapeutic interventions.

Since the Great East Japan Earthquake of March 11, 2011, and the tsunami and meltdowns that followed in its wake, there have been many moving stories about how the disaster impacted, and continues to impact, especially Japanese living in Fukushima and the Sanriku Coast. Meanwhile, in Tokyo, life returned to normal for the vast majority of the population within a few years. March 2011 and its aftermath seem like distant memories, something that happened a long time ago in a region far, far away.

The betatron radiation source features a micrometer-scale source size, a femtosecond-scale pulse duration, milliradian-level divergence angles and a broad spectrum exceeding tens of keV. It is conducive to the high-contrast imaging of minute structures and for investigating interdisciplinary ultrafast processes. In this study, we present a betatron X-ray source derived from a high-charge, high-energy electron beam through a laser wakefield accelerator driven by the 1 PW/0.1 Hz laser system at the Shanghai Superintense Ultrafast Laser Facility (SULF). The critical energy of the betatron X-ray source is 22 ± 5 keV. The maximum X-ray flux reaches up to 4 × 109 photons for each shot in the spectral range of 5–30 keV. Correspondingly, the experiment demonstrates a peak brightness of 1.0 × 1023 photons·s−1·mm−2·mrad−2·0.1%BW−1, comparable to those demonstrated by third-generation synchrotron light sources. In addition, the imaging capability of the betatron X-ray source is validated. This study lays the foundation for future imaging applications.

For binary plug nozzle, the plug cone is exposed to high-temperature mainstream flow, making it one of the nozzle’s high-temperature components. This paper uses the Realizable k-ε turbulence model and the reverse Monte Carlo method to numerically investigate the aerodynamic and infrared radiation characteristics of the plug nozzle. Various slot cooling configurations were adopted to study the nozzle’s infrared radiation in detail. Results indicate that compared to the baseline nozzle, the plug nozzle’s performance is slightly reduced due to the decrease in effective area of flow over the plug cone. Introducing slot cooling at the rear edge provides significant infrared suppression benefits at low detection angles and notably reduces infrared radiation discrepancy with baseline nozzle at high detection angles. The cooling air from slots causes the nozzle jet to exhibit a ‘thermal layered’ feature. With the same total coolant mass flow, the ‘leading edge + trailing edge’ cooling configuration can lower the area-averaged wall temperature of the plug cone by 5.5% – 12.3%. However, its infrared radiation intensity at each detection angle on the pitch detection plane is higher than that of the ‘trailing edge’ configuration. The significance of leading-edge cooling is focused more on thermal protection for the plug. Thus, it is essential to balance coolant mass flow distribution between infrared radiation suppression and thermal protection.