In this work, the correlations between streamwise velocity and temperature fluctuations are investigated in compressible turbulent channel flows from the perspective of coherent structures. The intense fluctuation structures and quadrant-event structures of both velocity and temperature have been identified, extracted separately and compared. Analyses show that although their structure sizes are similar in the whole channel, high correlation only exists in the near-wall region with a high overlapping rate of the instantaneous structures. The hierarchy of the temperature structures are passively formed following the dynamic process of the velocity such as ejections, which contributes to the remaining correlation in the outer layer. However, this passive scalar property cannot provide the production mechanism in the outer layer according to the budget analysis after scale decomposition, and the interscale energy transfer progress is also different from the velocity fluctuation field. Therefore, the temperature structures deviate from the velocity structures in the outer layer and cannot be carried by the following dynamic process of the velocity such as sweeps, passively, which can be found from the conditional averaged structures. All of these findings provide a new perspective for understanding the velocity–temperature relationship in compressible channel flows.

Previous studies highlighted the health benefits of coffee and tea, but they only focused on the comparisons between different consumptions. Consequently, the association estimate lacked a clear interpretation, as the substitution of beverages and distribution of doses were not explicitly prescribed. We focused on the ‘relative association’ to ascertain the optimal consumption strategy (including total intake and optimal allocation strategy) for coffee, tea and plain water associated with decreased mortality. Self-reported coffee, tea and plain water intake were used from the UK Biobank. Within a compositional data analysis framework, a multivariate Cox model was used to assess the relative associations after adjusting for a range of potential confounders. The lower mortality risk was observed with at least approximately 7–8 drinks/d of total consumption. When the total intake > 4 drinks/d, substituting plain water with coffee or tea was linked to reduced mortality; nevertheless, the benefit was not seen for ≤ 4 drinks/d. Besides, a balanced consumption of coffee and tea (roughly a ratio of 2:3) associated with the lowest hazard ratios of 0·55 (95 % CI 0·47, 0·64) for all-cause mortality, 0·59 (95 % CI 0·48, 0·72) for cancer mortality, 0·69 (95 % CI 0·49, 0·99) for CVD mortality, 0·28 (95 % CI 0·15, 0·52) for respiratory disease mortality and 0·35 (95 % CI 0·15, 0·82) for digestive disease mortality than other combinations. These results highlight the importance of the rational combination of coffee, tea and plain water, with particular emphasis on ensuring adequate total intake, offering more comprehensive and explicit guidance for individuals.

The $L^p$ boundedness of the commutator $[b, T]$ has been intensively studied in recent decades in part because it has important connections and applications to partial differential equations. Inspired by these works, we study the boundedness and compactness of the Riesz transform commutator in a general setting, namely, in the scale of Lorentz spaces and on stratified Lie groups. In this article, we provide a complete characterization between the space of the symbol b and the Lorentz estimates of $[b, R_j]$.

This study investigates the effects of thermal buoyancy on the ascent or descent dynamics and path instabilities of a finite-size sphere through direct numerical simulations with the immersed boundary method. By parametrically varying the density ratio $(\rho _r)$, Richardson number $({\textit{Ri}})$ and Galileo number $(\textit{Ga})$, four distinct motion regimes are identified: stable vertical, zigzagging, spiralling and chaotic regimes. These regimes emerge from the competition between particle inertial, gravitational forces and fluid thermal-buoyant forces. Compared with isothermal cases, particles with positive Richardson numbers exhibit accelerated motion due to thermal buoyancy. The critical Reynolds numbers ${\textit{Re}}_{p,cr}$ for their path instability are significantly reduced by amplifying wake recirculation zones and triggering vortex shedding. This destabilization mechanism is markedly more pronounced for light particles $(\rho _r \lt 1)$ than heavy particles $(\rho _r \gt 1)$. The present results reveal that the dynamics of heated light particles $(\rho _r=0.5, {\textit{Ri}}\gt 0)$ are governed by the codependent interplay of thermal-buoyancy intensity (${\textit{Ri}}$) and gravitational force (${\textit{Ga}}$), which collectively dictate velocity modulation and path instability patterns. Notably, thermal buoyancy elevates particle Reynolds numbers $({\textit{Re}}_p)$ while could reduce Nusselt numbers, arising from competing mechanisms between intensified convective transport and impaired conductive heat transfer – particularly pronounced for low ${\textit{Ga}}$ particles. These findings bridge the gap between fundamental fluid mechanics and thermal engineering, offering insights to optimize thermal management in particle-laden flows systems, such as industrial heat exchangers and fluidized bed reactors, where thermohydrodynamic coupling effect plays a key role in the performance.

In recent years, integrating physical constraints within deep neural networks has emerged as an effective approach for expediting direct numerical simulations in two-phase flow. This paper introduces physics-informed neural networks (PINNs) that utilise the phase-field method to model three-dimensional two-phase flows. We present a fully connected neural network architecture with residual blocks and spatial parallel training using the overlapping domain decomposition method across multiple graphics processing units to enhance the accuracy and computational efficiency of PINNs for the phase-field method (PF-PINNs). The proposed PINNs framework is applied to a bubble rising scenario in a three-dimensional infinite water tank to quantitatively assess the performance of PF-PINNs. Furthermore, the computational cost and parallel efficiency of the proposed method was evaluated, demonstrating its potential for widespread application in complex training environments.

Within the broad context of design research, joint attention within co-creation represents a critical component, linking cognitive actors through dynamic interactions. This study introduces a novel approach employing deep learning algorithms to objectively quantify joint attention, offering a significant advancement over traditional subjective methods. We developed an optimized deep learning algorithm, YOLO-TP, to identify participants’ engagement in design workshops accurately. Our research methodology involved video recording of design workshops and subsequent analysis using the YOLO-TP algorithm to track and measure joint attention instances. Key findings demonstrate that the algorithm effectively quantifies joint attention with high reliability and correlates well with known measures of intersubjectivity and co-creation effectiveness. This approach not only provides a more objective measure of joint attention but also allows for the real-time analysis of collaborative interactions. The implications of this study are profound, suggesting that the integration of automated human activity recognition in co-creation can significantly enhance the understanding and facilitation of collaborative design processes, potentially leading to more effective design outcomes.

We investigate the dynamics of circular self-propelled particles in channel flow, modelled as squirmers using a two-dimensional lattice Boltzmann method. The simulations explore a wide range of parameters, including channel Reynolds numbers ($\textit{Re}_c$), squirmer Reynolds numbers ($\textit{Re}_s$) and squirmer-type factors ($\beta$). For a single squirmer, four motion regimes are identified: oscillatory motion confined to one side of the channel, oscillatory crossing of the channel centreline, stabilisation at a lateral equilibrium position with the squirmer tilted and stable upstream swimming near the channel centreline. For two squirmers, interactions produce not only these four corresponding regimes but also three additional ones: continuous collisions with repeated position exchanges, progressive separation and drifting apart and, most notably, the formation of a stable wedge-like conformation (regime D). A key finding is the emergence of regime D, which predominantly occurs for weak pullers ($\beta = 1$) and at moderate to high $\textit{Re}_c$ values. Hydrodynamic interactions align the squirmers with streamline bifurcations near the channel centreline, enabling stability despite transient oscillations. Additionally, the channel blockage ratio critically affects the range of $\textit{Re}_s$ values over which this regime occurs, highlighting the influence of geometric confinement. This study extends the understanding of squirmer dynamics, revealing how hydrodynamic interactions drive collective behaviours. The findings also offer insights into the design of self-propelled particles for biomedical applications and contribute to the theoretical framework for active matter systems. Future work will investigate three-dimensional effects and the stability conditions for spherical squirmers forming stable wedge-like conformations, further generalising these results.

In this study, the propagation behaviour of detonation waves in a channel filled with stratified media is analysed using a detailed chemical reaction model. Two symmetrical layers of non-reactive gas are introduced near the upper and lower walls to encapsulate a stoichiometric premixed H2–air mixture. The effects of gas temperature and molecular weight of the non-reactive layers on the detonation wave’s propagation mode and velocity are examined thoroughly. The results reveal that as the non-reactive gas temperature increases, the detonation wave front transitions from a ‘convex’ to a ‘concave’ shape, accompanied by an increase in wave velocity. Notably, the concave wave front comprises detached shocks, oblique shocks and detonation waves, with the overall wave system propagating at a velocity exceeding the theoretical Chapman–Jouguet speed, indicating the emergence of a strong detonation wave. Furthermore, when the molecular weight of non-reactive layers varies, the results qualitatively align with those obtained from temperature variations. To elucidate the formation mechanism of different detonation wave front shapes, a dimensionless parameter $\eta$ (defined as a function of the specific heat ratio and sound speed) is proposed. This parameter unifies the effects of temperature and molecular weight, confirming that the specific heat ratio and sound speed of non-reactive layers are the primary factors governing the detonation wave propagation mode. Additionally, considering the effect of mixture inhomogeneity on the detonation reaction zone, the stream tube contraction theory is proposed, successfully explaining why strong detonation waves form in stratified mixtures. Numerical results show good agreement with theoretical predictions, validating the proposed model.

We show that attention constraints on decision-makers create barriers to financial inclusion. Using administrative data on retail loan-screening processes, we find that attention-constrained loan officers exert less effort reviewing applicants of lower socioeconomic status (SES) and reject them more frequently. More importantly, when externally imposed increases in loan officers’ workloads tighten attention constraints, loan officers are even more prone to quickly reject low-SES applicants but quickly accept very high-SES applicants without careful review. Such selective attention allocation further widens the approval rate gap between high- and low-SES applicants—a unique prediction of this attention-based mechanism.

We present 35 AMS 14C dates from 26 horizons on a 30-cm gravity core from Shira Lake in the republic of Khakassia, Central Russia. The chronology of the core is determined by 210Pb/137Cs dating results and interpretation of elemental geochemistry with historic documents, covering deposition since ca. 1870 CE. This study assesses the old carbon influence (OCI) on organic carbon 14C by comparison with the 210Pb/137Cs dates, sources of carbon, and lake conditions interpreted from elemental proxies. These include elemental concentrations in 0.5N HCl leaches and Aqua Regia dissolution fractions, as well as organic C, N and C/N measurements. From these data we establish a succession of the following six zones: I) (1870∼1900 CE) relatively fresh lake with high lake level, low productivity and high surface runoff (wet conditions); II) (1900∼1940 CE) a “white zone” reflected by high carbonate and low magnetic signal formed in a saline, oxidizing and holomictic lake stage; III) (1940∼1963 CE) reduced carbonate with elevated organic C, N, C/N, Mo and magnetic signal, indicating a stratified and anaerobic lake; IV) (1963∼1994 CE) increased salinity and productivity with the highest observed magnetic signal and elevated heavy metal and Mo contents, implying enhanced anoxic conditions and human impact; V) (1994∼2003 CE) high C/N, organic and carbonate contents suggesting meromictic and anaerobic lake conditions; VI) (2003∼2020 CE) decreased carbonate content with increased organic C and N, and heavy metals showing a deteriorating lake environment under human impact.

This paper presents a compact broad dual-band rectifier based on a transmission line matching network. This method improves the overall impedance matching performance over two bands, and improves bandwidth of the rectifier’s efficiency. A π-type direct current filter with excellent harmonic suppression performance is proposed. The multi-section transmission line used as the dual-band input impedance matching network is analyzed to achieve an arbitrary frequency ratio. A rectifier is designed and implemented using a three-stage transmission-line matching network. Simulation and experimental results show that a dual-band rectifier is successfully performed with the measured power conversion efficiency (PCE) of 75.7% and 76.3% at 0.915 and 2.45 GHz, respectively. Additionally, the rectifier exhibits bandwidths of 0.48 and 0.25 GHz when the PCE exceeds 70%. Significant enhancement of bandwidth over conventional rectifiers is demonstrated.

A high-energy pulsed vacuum ultraviolet (VUV) solid-state laser at 177 nm with high peak power by the sixth harmonic of a neodymium-doped yttrium aluminum garnet (Nd:YAG) amplifier in a KBe2BO3F2 prism-coupled device was demonstrated. The ultraviolet (UV) pump laser is a 352 ps pulsed, spatial top-hat super-Gaussian beam at 355 nm. A high energy of a 7.12 mJ VUV laser at 177 nm is obtained with a pulse width of 255 ps, indicating a peak power of 28 MW, and the conversion efficiency is 9.42% from 355 to 177 nm. The measured results fitted well with the theoretical prediction. It is the highest pulse energy and highest peak power ever reported in the VUV range for any solid-state lasers. The high-energy, high-peak-power, and high-spatial-uniformity VUV laser is of great interest for ultra-fine machining and particle-size measurements using UV in-line Fraunhofer holography diagnostics.

The migration of Mongolian gazelles (Procapra gutturosa) poses a potential risk of outbreak for zoonotic intestinal protozoan parasite infections. This study aims to investigate the infection status of zoonotic intestinal protozoan parasites in these migratory Mongolian gazelles. We collected 120 fecal samples from Mongolian gazelles during their migration from Mongolia to China in December 2023. These samples were analysed using amplification and sequencing of partial SSU rRNA genes to detect the 4 presence of zoonotic intestinal protozoan parasites and characterize their genotypes. Our analysis revealed the presence of several zoonotic intestinal protozoan parasites in the sampled Mongolian gazelles. Cryptosporidium spp. was detected in 14.17% (17/120) of the samples, followed by Cystoisospora belli in 13.33% (16/120), Blastocystis sp. in 16.67% (20/120) and Cyclospora cayetanensis in 30.00% (36/120). Moreover, we identified novel host-adapted genotypes of Cryptosporidium spp. and C. belli, as well as the presence of ST2 and ST13 Blastocystis sp. subtypes, while distinct genotypes were found in Blastocystis sp. and C. cayetanensis. This study revealed the status of 4 prevalent zoonotic intestinal protozoan parasite infections in Mongolian gazelles and provided crucial insights into their characteristics. The prevalence of these parasites in the population highlights the potential risk of cross-border transmission of infectious diseases associated with long-distance migration. Furthermore, the identification of novel genotypes contributes to our understanding of the genetic diversity and adaptation of these parasites. These findings can inform the development of protective measures to mitigate the impact of these infections on the health and survival of Mongolian gazelles.

In this article, we study the following Schrödinger equation

\begin{align*}\begin{cases}-\Delta u -\frac{\mu}{|x|^2} u+\lambda u =f(u), &\text{in}~ \mathbb{R}^N\backslash\{0\},\\\int_{\mathbb{R}^{N}}|u|^{2}\mathrm{d} x=a, & u\in H^1(\mathbb{R}^{N}),\end{cases}\end{align*}

where $N\geq 3$, a > 0, and $\mu \lt \frac{(N-2)^2}{4}$. Here $\frac{1}{|x|^2} $ represents the Hardy potential (or ‘inverse-square potential’), λ is a Lagrange multiplier, and the nonlinearity function f satisfies the general Sobolev critical growth condition. Our main goal is to demonstrate the existence of normalized ground state solutions for this equation when $0 \lt \mu \lt \frac{(N-2)^2}{4}$. We also analyse the behaviour of solutions as $\mu\to0^+$ and derive the existence of normalized ground state solutions for the limiting case where µ = 0. Finally, we investigate the existence of normalized solutions when µ < 0 and analyse the asymptotic behaviour of solutions as $\mu\to 0^-$.

This paper presents a compact and ultra-wideband high-efficiency microwave rectifier for wireless power transmission (WPT) applications. The input-matching-network utilizes a compact asymmetric coupled transmission line structure, contributing to wideband performance. The rectifier adopts a voltage-doubler topology, resulting in a smooth input impedance across a wide bandwidth. The working principle of the asymmetric coupled transmission line matching network is analyzed. Simulation and measurement are conducted on the proposed rectifier. The fabricated prototype demonstrates a wide bandwidth of 162.5% (0.3–2.9 GHz with the power conversion efficiency (PCE) exceeding 60% at an input power of 18 dBm. Even at an input power of 10 dBm, the measured PCE remains above 50% over the working band. The proposed ultra-wideband rectifier shows promising potential for WPT applications including wireless powering of low-power electronic devices and sensors.

This study examined the sour grapes/sweet lemons rationalization through 2 conditions: ‘attainable’ (sweet lemons) and ‘unattainable’ (sour grapes), reflecting China’s 2019-nCoV vaccination strategy. The aim was to find ways to change people’s beliefs and preferences regarding vaccines by easing their safety concerns and encouraging more willingness to get vaccinated. An online survey was conducted from January 22 to 27, 2021, with 3,123 residents across 30 provinces and municipalities in the Chinese mainland. The direction of belief and preference changed in line with the sour grapes/sweet lemons rationalization. Using hypothetical and real contrasts, we compared those for whom the vaccine was relatively unattainable (‘sour grapes’ condition) with those who could get the vaccine easily (‘sweet lemons’). Whether the vaccine was attainable was determined in the early stage of the vaccine roll-out by membership in a select group of workers that was supposed to be vaccinated to the greatest extent possible, or, by being in the second stage when the vaccine was available to all. The attainable conditions demonstrated higher evaluation in vaccine safety, higher willingness to be vaccinated, and lower willingness to wait and see. Hence, we propose that the manipulation of vaccine attainability, which formed the basis of the application of sour grapes/sweet lemons rationalization, can be utilized as a means to manipulate the choice architecture to nudge individuals to ease vaccine safety concerns, reducing wait-and-see tendencies, and enhancing vaccination willingness. This approach can expedite universal vaccination and its associated benefits in future scenarios resembling the 2019-nCoV vaccine rollout.

Increases in population size are associated with the adoption of Neolithic agricultural practices in many areas of the world, but rapid population growth within the Dingsishan cultural group of southern China pre-dated the arrival of rice and millet farming in this area. In this article, the authors identify starch grains from taros (Colocasia) and yams (Dioscorea) in dental calculus and on food-processing tools from the Dingsishan sites of Huiyaotian and Liyupo (c. 9030–6741 BP). They conclude that the harvesting and processing of these dietary staples supported an Early Holocene population increase in southern East Asia, before the spread of rice and millet farming.

A low-cost and computer-controlled graphitization system connected to an elemental analyzer (EA) has been designed and built at the NTUAMS Lab. This semiautomatic system equips 6-unit reactors for the graphitization of CO2 with H2 on the iron catalyst. The entire procedure takes about 7 hours for iron conditioning, sample combustion and loading, and graphitization. The system can produce good-quality graphite for samples containing 0.5–1.6 mg carbon mass, with the pressure yield of graphitization ranging from 57.7% to 87.1%. The average values of OXI and OXII agree well with the consensus value, but the result of ANU sucrose was observed to be slightly higher than the reported one. The background samples of anthracite over ten months yielded an average of 0.38±0.10 pMC (n=21) corresponding to a 14C age of 45 kyr BP. Intercomparison samples L and M of FIRI exhibit that the measured 14C ages are almost identical to the consensus values and have a small spread in these values. The system has been carrying out graphitization for total organic carbon (TOC) of peat samples, and providing a more efficient and convenient way for AMS 14C dating.