The real-fluid effect induced by large density variation at supercritical pressure (SCP) modulates the turbulent dynamics and heat transfer, and poses challenges to existing turbulence models that are based on ideal-gas conditions. This study conducts direct numerical simulations of fully developed channel flows at SCP, with the upper and lower channel walls being isothermally heated and cooled, respectively. Emphasis is placed on examining the effects of various levels of density variations on near-wall turbulence as well as turbulent heat transfer by changing wall temperatures. The results show that the density fluctuation significantly impacts both first-order and second-order turbulence statistics near the heated wall owing to the close vicinity of pseudo-boiling point. Such real-fluid impact increases substantially with increasing density ratio, and tends to weaken the turbulent kinetic energy by damping turbulence production, while simultaneously inducing an additional turbulent mass flux that partially offsets this reduction. Detailed quadrant analysis reveals that the ‘ejection’ events dominate diverse effects of density fluctuation on Reynolds shear stresses, with density fluctuation contributing positively on the cooled wall side, and negatively on the heated wall side. Regarding the turbulent heat transfer, density fluctuation enhances the enthalpy–pressure–gradient correlation, tending to weaken the turbulent heat flux, which is slightly compensated by additional terms induced by density fluctuations. The overall negative contribution of density fluctuation to turbulent heat flux stems primarily from ‘hot ejection’ motions. Instantaneous flow characteristics provide additional support for these findings. Additionally, the mechanisms by which density fluctuations affect Reynolds shear stress and turbulent heat flux could also be extended to the skin friction coefficient and Nusselt number, respectively.

Bombyx mori Tryptophanyl-tRNA synthetase (BmWARS) belongs to the family of Ic-like aminoacyl-tRNA synthetases (aaRSs), whose specific recognition of the substrate Trp, tRNA, maintains the fidelity of protein synthesis. In this study, BmWARS was cloned and characterized from the midgut of the silkworm, Bombyx mori, resulting in an open reading frame (ORF) with a full length of 1,149 bp, which can encode 382 Aa. BmWARS is localized in the cytoplasm, and is expressed in all tissues of the silkworm, with higher expression in the testis, ovary, silk gland and malpighian tubule. The expression of BmWARS was significantly up-regulated in the midgut and silk gland after infection with Bombyx mori nuclear polyhedrosis virus (BmNPV). In addition, overexpression of BmWARS inhibited BmNPV infection and replication extremely significantly, while interference with BmWARS expression promoted BmNPV infection and replication. Analysis of the immune pathways in which BmWARS may be involved revealed that the expression of the key genes of the PI3K-Akt pathway, BmPI3K, BmAkt, BmPDK1, BmeIF4E, BmS6, and p-Akt protein was significantly reduced, whereas the expression of BmPTEN, BmFoxO, and BmCaspase9 was significantly increased in the cells that overexpressed BmWARS and were infected with BmNPV. Meanwhile, the results of the study interfering with the expression of BmWARS were completely opposite to those of the study overexpressing BmWARS. This is the first report that BmWARS has antiviral effects in Bombyx mori. Moreover, BmWARS inhibits BmNPV infection and replication in Bombyx mori cells by promoting apoptosis and inhibiting cell proliferation.

This paper provides an overview of the current status of ultrafast and ultra-intense lasers with peak powers exceeding 100 TW and examines the research activities in high-energy-density physics within China. Currently, 10 high-intensity lasers with powers over 100 TW are operational, and about 10 additional lasers are being constructed at various institutes and universities. These facilities operate either independently or are combined with one another, thereby offering substantial support for both Chinese and international research and development efforts in high-energy-density physics.

Random effects meta-analysis model is an important tool for integrating results from multiple independent studies. However, the standard model is based on the assumption of normal distributions for both random effects and within-study errors, making it susceptible to outlying studies. Although robust modeling using the t distribution is an appealing idea, the existing work, that explores the use of the t distribution only for random effects, involves complicated numerical integration and numerical optimization. In this article, a novel robust meta-analysis model using the t distribution is proposed (tMeta). The novelty is that the marginal distribution of the effect size in tMeta follows the t distribution, enabling that tMeta can simultaneously accommodate and detect outlying studies in a simple and adaptive manner. A simple and fast EM-type algorithm is developed for maximum likelihood estimation. Due to the mathematical tractability of the t distribution, tMeta frees from numerical integration and allows for efficient optimization. Experiments on real data demonstrate that tMeta is compared favorably with related competitors in situations involving mild outliers. Moreover, in the presence of gross outliers, while related competitors may fail, tMeta continues to perform consistently and robustly.

A novel high-selectivity ultra-wideband (UWB) balanced bandpass filter (BPF) with harmonic suppression characteristics is proposed. The differential-mode UWB passband is constructed using quarter-wavelength asymmetrical parallel-coupled transmission lines, resulting in sharp filtering selectivity, while common-mode noises are suppressed by loading the T-type stubs. A simple design method of integrating bandstop filter branches into the BPF for third harmonic suppression without increasing the circuit size is described and confirmed. A planar high-selectivity balanced BPF prototype is manufactured and measured at 2.6 GHz with a measured 3-dB fractional bandwidth of 108% to validate the framework principle. More importantly, with third harmonic suppression characteristics, the measured out-of-band rejection is more than 20 dB, spanning 4.35 GHz until 12.4 GHz.

Substantial changes resulting from the interaction of environmental and dietary factors contribute to an increased risk of obesity, while their specific associations with obesity remain unclear. Identify inflammation-related dietary patterns (DPs) and explore their associations with obesity among urbanized Tibetan adults under significant environmental and dietary changes.Totally, 1826 subjects from the suburbs of Golmud City were enrolled in an open cohort study, of which 514 were followed up. Height, weight, and waist circumference were used to define overweight and obesity. DPs were derived using reduced rank regression with 41 food groups as predictors and hs-CRP and prognostic nutritional index as inflammatory response variables. Altitude was classified as high or ultra-high. Two DPs were extracted. DP-1 was characterized by having high consumptions of sugar-sweetened beverages, savory snacks, and poultry, and a low intake of tsamba. DP-2 had high intakes of poultry, pork, animal offal, and fruits, and a low intake of butter tea. Participants in the highest tertiles (T3) of DPs had increased risks of overweight and obesity (DP-1: OR=1.37, 95% CI: 1.07, 1.77; DP-2: OR=1.48, 95% CI: 1.18, 1.85) than those in the lowest tertiles (T1). Participants in T3 of DP-2 had an increased risk of central obesity (OR=2.25, 95% CI: 1.49, 3.39) than those in T1. The positive association of DP-1 with overweight and obesity was only significant at high altitudes, while no similar effect was observed for DP-2. Inflammation-related DPs were associated with increased risks of overweight and/or obesity.

Prehistoric humans seem to have preferred inhabiting small river basins, which were closer in distance to most settlements compared to larger rivers. The Holocene landscape evolution is considered to have played a pivotal role in shaping the spatiotemporal patterns of these settlements. In this study, we conducted comprehensive research on the relationship between landscape evolution and settlement distribution within the Huangshui River basin, which is a representative small river in Central China with numerous early settlements, including a prehistoric city known as the Wangjinglou site (WJL). Using geoarchaeological investigations, optically stimulated luminescence dating, pollen analysis, and grain-size analysis, we analyzed the characteristics of the Holocene environment. The results indicate the presence of two distinct geomorphic systems, namely the red clay hills and the river valley. The red clay hills, formed in the Neogene, represent remnants of the Songshan piedmont alluvial fan that was eroded by rivers. There are three grades of terraces within the river valley. T3 is a strath terrace and formed around 8.0 ka. Both T2 and T1 are fill terraces, which were developed around 4.0 ka and during the historical period, respectively. The sedimentary features and pollen analysis indicate the existence of an ancient lake-swamp on the platform during 11.0–9.0 ka. This waterbody gradually shrank during 9.0–8.0 ka, and ultimately disappeared after 8.0 ka. Since then, the development of large-scale areas of water ceased on the higher geomorphic units. River floods also cannot reach the top of these high geomorphic units, where numerous prehistoric settlements are located, including the Xia–Shang cities of the WJL site. Our research demonstrates that landscape stability supported the long-term and sustainable development of ancient cultures and facilitated the establishment of the WJL ancient cities in the region.

Stimulated Raman scattering is a third-order nonlinear optical effect that is not only effective for wavelength converting laser output, but also for single longitudinal-mode output due to the absence of spatial hole burning. Diamond is a prominent Raman-active medium that has significant potential for linewidth narrowing and wavelength converting lasers at high power levels due to its high thermal conductivity, long Raman frequency shift and wide spectral transmission range. In this work we utilize diamond in a resonantly mode-matched external cavity to achieve cascaded Raman conversion of a 1064 nm laser. By fine-tuning the length of this external cavity, we can obtain narrow linewidth emission at 1240 and 1485 nm. When operating at maximum power, the measured linewidths were more than twofold narrower than the linewidth of the fundamental field. In addition, the noise levels of the Stokes fields are lower than that of the fundamental field throughout the entire noise frequency range, and the intrinsic linewidth of the second Stokes field, which is expressed at the hertz level (~3.6 Hz), is decreased by approximately three orders of magnitude compared to that of the pump. This work represents the first measurement and analysis of the linewidth and noise characteristics of cascaded diamond Raman lasers and, significantly, offers a new means by which high-power, narrow linewidth laser output can be produced from wavelength-converted laser systems.

Time-domain characterization of ultrashort pulses is essential for studying interactions between light and matter. Here, we propose and demonstrate an all-optical pulse sampling technique based on reflected four-wave mixing with perturbation on a solid surface. In this method, a weak perturbation pulse perturbs the four-wave mixing signal generated by a strong fundamental pulse. The modulation signal of the four-wave mixing, which is detected in the reflection geometry to ensure a perfect phase-matching condition, directly reflects the temporal profile of the perturbation pulse. We successfully characterized multi-cycle and few-cycle pulses using this method. The reliability of our approach was verified by comparing it to the widely employed frequency-resolved optical gating method. This technique provides a simple and robust method for characterizing ultrashort laser pulses.

We study the melting process of a solid under microgravity, driven solely by lateral vibrations that are perpendicular to the applied temperature gradient due to the absence of gravity-induced convection. Using direct numerical simulations with the phase-field method, we examine two-dimensional vibration-induced melting in a square cavity over four orders of magnitude of vibrational Rayleigh numbers, $10^5\le Ra_{{vib}}\le 10^9$. Our results show that as melting progresses, the flow structure transitions from a periodic-circulation regime with diffusion-dominated heat transfer to a columnar regime with vibroconvection. The mean height of the liquid–solid interface follows a power-law dependency with time, $\bar {\xi } \sim \tilde t^{1/(2-2\alpha )}$, where $\alpha = 0$ in the periodic-circulation regime and $\alpha = 1/2$ in the columnar regime. We further observe that within the columnar regime, the morphological evolution of the liquid–solid interface is influenced by the interaction of columnar thermal plumes in the central regions and the peripheral flow near the sidewalls. Specifically, we offer a comprehensive analysis of the plume merging behaviour, which is governed by the aspect ratio ($\bar {\xi }$) of the liquid layer and the intensity of vibration, quantified by the effective vibrational Rayleigh number $Ra_{vib}^{eff}$. We identify the relationship between the number of columnar plumes $K_m$ and $Ra_{vib}^{eff}$, finding that $K_m \sim \bar {\xi }^{-1} (Ra_{vib}^{eff})^{\gamma }$ with the fitting scaling exponent $\gamma = 0.150 \pm 0.025$. We subsequently quantify the characteristics of the interface roughness amplitude evolution in microgravity vibroconvection. Our results indicate that the roughness amplitude exhibits a power-law dependence on the mean height of the liquid layer. Drawing from the Stefan boundary condition, we theoretically deduce this dependence under the assumption of a non-uniform heat flux distribution at the interface, where the theory is corroborated by our numerical simulations.

To meet the development needs of aeroengines for high thrust-to-weight ratios and fuel-air ratios, a high temperature rise triple-swirler main combustor was designed with a total fuel-air ratio of 0.037, utilising advanced technologies including staged combustion, multi-point injection and multi-inclined hole cooling. Fluent software was used to conduct numerical simulations under both takeoff and idle conditions, thereby obtaining the distribution characteristics of the velocity and temperature fields within the combustor, as well as the generation of pollutants. The simulation results indicate that under takeoff conditions, the high temperature rise triple-swirler combustor achieves a total pressure loss coefficient of less than 6% and a combustion efficiency exceeding 99%. Under takeoff conditions, the OTDF and RTDF values are 0.144 and 0.0738, respectively. The mole fraction of NOx emissions is 3,700ppm, while the mole fraction of soot emissions is 2.55×10−5ppm. Under idle conditions, the triple-swirler combustor maintains a total pressure loss coefficient of less than 6% and a combustion efficiency greater than 99.9%. The OTDF and RTDF values are 0.131 and 0.0624, respectively. The mole fractions of CO and UHC emissions are both 0×10−32ppm at the calculation limit of Fluent software.

Despite global efforts to end tuberculosis (TB), the goal of preventing catastrophic health expenditure (CHE) due to TB remains unmet. This cross-sectional study was conducted in Guizhou Province, Southwest China. Data were collected from the Hospital Information System and a survey of TB patients who had completed standardized antituberculosis treatment between January and March 2021. Among the 2 283 participants, the average total expenditure and out-of-pocket expenditure were $1 506.6 (median = $760.5) and $683.6 (median = $437.8), respectively. Health insurance reimbursement reduced CHE by 16.8%, with a contribution rate of 24.9%, and the concentration index changed from -0.070 prereimbursement to -0.099 postreimbursement. However, the contribution of health insurance varied significantly across different economic strata, with contribution rates of 6.4% for the lowest economic group and 53.1% for the highest group. For patients from lower socioeconomic strata, health insurance contributed 10.7% to CHE in the prediagnostic phase and 23.5% during treatment. While social health insurance alleviated the financial burden for TB patients, it did not provide sufficient protection for those in lower economic strata or during the prediagnostic stage. This study underscores the need for more effective and equitable subsidy policies for TB patients .

We report a high-power ultra-narrow fiber-coupled diode laser using a Faraday anomalous dispersion optical filter (FADOF) as an external cavity element. An external cavity suitable for both the fiber-coupled package and FADOF configuration has been proposed. Using a 87Rb-based FADOF as the frequency-selective element, we realized a 103 W continuous laser output with a uniform circular beam. The center wavelength was precisely locked at the D2 line of the Rb resonance, and the bandwidth was narrowed from 1.8 nm (free-running, full width at half maximum (FWHM)) to 0.013 nm (6.9 GHz, FWHM). The side mode suppression ratio reached 31 dB. Such diode lasers with precise wavelength and high spectral brightness have critical applications in many fields, such as high-energy gas laser pumping, spin-exchange optical pumping, Raman spectroscopy and nonlinear optics.

This paper presents a numerical study on the flow around two tandem circular cylinders beneath a free surface at a Reynolds number of $180$. The free-surface effects on the wake dynamics and hydrodynamic forces are investigated through a parametric study, covering a parameter space of gap ratios from $0.20$ to $2.00$, spacing ratios from $1.50$ to $4.00$ and Froude numbers from $0.2$ to $0.8$. A jet-like flow accompanied by a shear layer of positive vorticity separating from the free surface is formed in the wake at small gap ratios, which significantly alters the wake pattern through its dynamic behaviours. At shallow submergence depths, the three-dimensional wake transitions from mode B to mode A as the distance between the cylinders increases. As submergence depth increases, the wavy deformation of the primary vortex cores disappears in the wake, and the flow transitions to a two-dimensional state. Higher Froude numbers can extend the effect of the free surface to deeper submergence depths. The critical spacing ratio tends to be larger at higher Froude numbers. Furthermore, the free-surface deformation is examined. The free-surface profile typically comprises a hydraulic jump immediately ahead of the upstream cylinder, trapped waves in the vicinity of the two tandem cylinders and well-defined travelling waves on the downstream side. The frequencies of the waves cluster around the vortex shedding frequency, indicating a close association between the generation of waves and the vortex shedding process.

China was a centre for early plant domestication, millets in the north and rice in the south, with both crops then spreading widely. The Laoguantai Culture (c. 8000–7000 BP) of the middle Yellow River region encompasses a crucial stage in the transition from hunting and gathering to farming, yet its subsistence basis is poorly understood. The authors present archaeobotanical data from the site of Beiliu indicating that farmers exploited a variety of wild and cultivated plants. The predominance of broomcorn millet accords with other Neolithic cultures in northern China but the presence of rice—some of the earliest directly dated examples—opens questions about the integration of rice cultivation into local subsistence strategies.