In this paper, we study a nonlinear free boundary problem modelling the growth of radially symmetric tumours. The tumour consists of a central necrotic core, an intermediate quiescent layer and an outer proliferating shell. The evolution of tumour layers and the movement of the tumour boundary are totally governed by external nutrient supply and conservation of mass. The three-layer structure generates three free boundaries with discontinuous nutrient consumption rates and cell growth rates. We develop a nonlinear analysis method to clarify the interactive relationships among free boundaries. By carefully studying the dependence of the critical-state tumour growth rate on the external nutrient concentration, we reveal the evolutionary mechanism in tumour growth and the mutual transformation of its internal structures. The existence and uniqueness of the radial stationary solution is proved, and its globally asymptotic stability towards different dormant tumour states is established.

The flow behaviour of an inclined jet in crossflow (JICF) subjected to different upstream roughness regimes – smooth, transitionally rough (${k}_{s}/{D}=0.129$, where $k_{s}$ is the equivalent roughness height and $D$ is the jet hole diameter) and fully rough (${k}_{s}/{D}=0.782$) – is investigated using refractive-index-matching time-resolved particle image velocimetry for velocity ratios VR = 0.33, 0.67 and 1.0. The transitionally rough regime produces intensified, unbroken large-scale vortices that induce strong intermittency in the boundary-layer thickness. Its energy spectrum retains the original multi-scale coherence, but exhibits an additional wavelength associated with this intermittency. This intermittent state imposes the strongest unsteady influence on the downstream JICF, manifested as a binary flow pattern consisting of alternating jet lift-off and regular shedding. Time-averaged fields show a vertically elongated counter-rotating vortex pair (CRVP), while extended spectral proper orthogonal decomposition (ESPOD) indicates that the binary state drives modal bifurcation and distinct pathways associated with prematurely initiated centreline disturbance amplification. In contrast, the fully rough regime promotes rapid breakdown into small-scale turbulence. The ESPOD confirms that multi-scale frequency coherence decays rapidly, whereas low-frequency coherence experiences a brief amplification due to upstream signal injection. Additionally, secondary flows are observed to exert a localised, asymmetric modulation of the CRVP at VR ≤ 0.67: on the high-momentum pathway (downwash) side, one CRVP lobe is vertically compressed and its decay is delayed, while on the low-momentum pathway (upwash) side, the opposite lobe is vertically stretched and its decay is accelerated.

Personal networks provide crucial support during crises, yet people are embedded in different network types that structure unequal access to such resources. The current study integrates these perspectives to examine whether—and how—network turnover contributed to disparities in mental health across socioeconomic status (SES) groups during the pandemic. Using two-wave panel data from the COVID-19 Pandemic and Social Network Panel Study (2020–2021), an egocentric network study of the college population in Wuhan, we employ random forests and spectral clustering to identify 7 types of core networks based on 43 network variables (i.e., Family, Friend, Restricted, Family & Community, School & Career, Just Activity, and Homebody). We find that as local social-distancing policies tightened, respondents increasingly shifted to Family and Friend networks and withdrew from School & Career and Just Activity. Individual fixed-effect models reveal that these network turnovers have heterogeneous mental health consequences net of observed and time-invariant unobserved confounders. Moving into Family and Friend networks yields the most favorable mental health outcomes for higher-SES groups, whereas benefits are less pronounced and even reversed among lower-SES groups. This pattern is consistent with SES-based differences in social support available in these network types. The current research advances an updated machine-learning approach for identifying personal network typologies. It also shows how the pandemic laid bare unequal resources embedded in personal networks and intensified health-related social inequality, underscoring the need to theorize network effects as contingent on individuals’ social status and the contexts in which networks are formed and embedded.

This work presents an integrated modelling study of fast-proton distributions generated by ion cyclotron range of frequency (ICRF) minority heating in the Experimental Advanced Superconducting Tokamak (EAST). Using a series of high-confinement (H-mode) discharges with increasing ICRF power levels from 0.8 to 2.4 MW, fast protons were produced via minority heating mechanisms and analysed through simulations using the ASCOT code. The results reveal that the fast protons are primarily concentrated near the fundamental cyclotron resonance layer and exhibit strong power-dependent behaviour in both real-space (R–Z) distribution and velocity space, where R is the major radius and Z is the vertical coordinate. As the ICRF power increases, the energetic proton population shows significant spatial broadening and energy enhancement, reaching up to 1 MeV. The fast-ion pitch-angle distribution becomes increasingly anisotropic, with high-energy ions concentrated around $|\textit{v}_{\|}/\textit{v}| \lt 0.5$, where $\nu$ is the magnitude (speed) of the full velocity vector of the particle. Furthermore, the energy density of fast ions aligns well with the ICRF power deposition profile, confirming efficient central-core heating. These findings, which provide insight into fast-ion behaviour and ICRF heating characteristics in EAST plasmas, also support future fast-ion diagnostics and performance control strategies in EAST and similar experimental conditions.

This study focuses on developing a predictive model for mean velocity profiles and total shear stress profiles in turbulent boundary layers subjected to adverse pressure gradients, especially with local disequilibrating effects. A new scaling using friction velocity modified by the Clauser pressure gradient parameter is introduced, and an estimation–correction model is developed, explicitly incorporating a streamwise derivative of pressure gradient, which effectively captures local disequilibrating effects beyond the reach of Reynolds-averaged Navier–Stokes equations. With the help of the model, the total shear stress is decomposed into four parts, representing respectively the Reynolds number effect, the equilibrium pressure gradient effect, the coupling between free-stream velocity and pressure gradient, and the local non-equilibrium pressure gradient effect. The latter two are considered first-order local disequilibrating effects, and can account for up to approximately half of the total stress. The model’s accuracy in predicting both mean velocity profiles and total shear stress profiles is validated against a wide range of DNS/LES datasets, with Clauser pressure gradient parameter $\beta$ reaching a maximum of $4.53$, $ \textit{Re}_\theta$ peaking at $9.65\times 10^3$, and the non-dimensional second-order streamwise pressure gradient $\gamma$ ranging from $-4.57\times 10^{-3}$ to $2.82\times 10^{-4}$.

This study combines corpus-based comparison and open-ended survey data to investigate kinship terminology usage in introductory contexts across languages. Focusing on the expression ‘this/here is my brother’, it examines how speakers of English and Chinese introduce a brother, with particular attention to whether they use a kinship term alone or add an appositive personal name. In addition, an open-ended questionnaire was completed by 119 participants representing 10 language backgrounds. The study further explores the cognitive motivations underlying these cross-linguistic differences in introductory kinship expressions. The results show that: (1) in the corpus data, Chinese speakers tend to introduce their brothers using kinship term alone, whereas English speakers typically include the brother’s personal name; (2) the questionnaire data suggest that many European-language speakers prefer a ‘kinship term + name’ pattern, whereas East Asian-language speakers more often rely on the kinship term alone and (3) these patterns can be interpreted with reference to the Focus-Shift Principle, the Principle of Least Effort and Typological Markedness. Overall, the study extends the English–Chinese corpus comparison to a broader multilingual sample and offers a cognitively informed account of recurring cross-linguistic tendencies in brother-introduction contexts.

Environmental insecticide residues are a growing concern in the management of disease-vector mosquitoes, such as Aedes albopictus (Diptera: Culicidae). While deltamethrin is extensively utilised in mosquito vector control, localised or intermittent sublethal exposure to this insecticide may influence mosquito population dynamics. To investigate the role of environmental residual deltamethrin in inducing transgenerational fitness costs in Ae. albopictus, this study established three different concentrations of deltamethrin solution based on its half-lethal concentration (0.002275 mg/L) for long-term exposure. And four consecutive generations were reared under these conditions. We monitored macroscopic growth and developmental data, reproductive capacity, and expression levels of yolk protein genes (vitellogenin) in each generation. Results showed that sublethal multigenerational deltamethrin exposure significantly prolonged the developmental period of Ae. albopictus; however, it did not have a significant impact on pupation or eclosion rates. In terms of fecundity, exposure to deltamethrin reduced the relative expression levels of vitellogenin-A1 and vitellogenin-C in Ae. albopictus, which was correlated with reduced reproductive output. Furthermore, there was a reduction observed in both single female oviposition rates and egg hatching success among exposed individuals. These findings highlight sublethal responses that may impact population dynamics and reproductive success in the field, underscoring the importance of considering chronic, low-dose insecticide effects in integrated vector management strategies.

Childhood adversity impairs well-being, yet psychological resilience may buffer its impact. Using resting-state fMRI in 94 rural Chinese children (ages 10–14), we examined whether psychological resilience protects brain network connectivity from adversity and its relevance to psychological well-being. Psychological resilience significantly moderated the impact of abuse, but not neglect, on limbic connectivity. Low-resilience children exposed to abuse showed heightened limbic-somatomotor and limbic-ventral attention connectivity, which predicted greater somatization and depression at baseline and more severe levels of anxiety six months later. These associations were absent in high-resilience children. Our findings reveal that psychological resilience specifically shields against the neurotoxic effects of abuse by modulating networks involved in emotion regulation, salience, and sensorimotor processing. Targeted interventions should consider adversity dimensions and psychological resilience capacity to mitigate long-term mental health risks.