Aiming at the problem of fast and consensus obstacle avoidance of multiple unmanned aerial systems in undirected network, a multi-quadrotor unmanned aerial vehicles UAVs (QUAVs) finite-time consensus obstacle avoidance algorithm is proposed. In this paper, multi-QUAVs establish communication through the leader-following method, and the formation is led by the leader to fly to the target position automatically and avoid obstacles autonomously through the improved artificial potential field method. The finite-time consensus protocol controls multi-QUAVs to form a desired formation quickly, considering the existence of communication and input delay, and rigorously proves the convergence of the proposed protocol. A trajectory segmentation strategy is added to the improved artificial potential field method to reduce trajectory loss and improve the task execution efficiency. The simulation results show that multi-QUAVs can be assembled to form the desired formation quickly, and the QUAV formation can avoid obstacles and maintain the formation unchanged while avoiding obstacles.

Investigations are conducted on the effect of wall proximity on the flow around a cylinder under an axial magnetic field, using the electrical potential probe technology to measure the velocity of liquid metal flow. The study focused on the impact of the inlet velocity of the fluid, the magnetic field and wall proximity on the characteristics of velocity fields, particularly on the vortex-shedding mode. Based on different magnitudes of the magnetic field and the distance from the cylinder to the duct wall, three types of vortex-shedding modes are identified, (I) shear layer oscillation state, (II) quasi-two-dimensional vortex-shedding states and (III) transition of the magnetohydrodynamic to hydrodynamic Kármán street. The transitions between these modes are analysed in detail. The experimental results show that the weak wall-proximity effect leads to the formation of the Kármán vortex street, while a reverse Kármán vortex street and secondary vortices emerge under a strong wall-proximity effect. It is noticed that the Kelvin–Helmholtz instability drives vortex shedding under regime I, leading to an increase in the Strouhal number (St) with stronger magnetic fields. Additionally, under a strong axial magnetic field, the wall-proximity effect (‘Shercliff layer effect’) promotes the instability of shear layers on both sides of the cylinder. These unique coupling effects are validated by variations in modal coefficients and energy proportions under different vortex-shedding regimes using the proper orthogonal decomposition method.

A moving static pressure distribution is commonly used to simulate a travelling ship. However, the ship movement changes the fluid velocity around the hull, inducing pressures on the hull surface that are no longer equal to the static pressure. Therefore, we introduce a dynamic pressure correction strategy, which can accurately simulate the impact of the ship movement on the hull-surface pressure and preserve the desired hull shape under both stationary and transient conditions. The strategy is applied to a high-order spectral model and used to investigate ship-induced waves and wave resistance over a both flat and variable topography. We explore various parameters in our study, including the average water depth to ship draft ratio ($h_0/d$), the channel width to ship width ratio ($W/B$), the Froude number ($Fr_0=U/\sqrt {gh_0}$) and variations in bathymetric slope. Compared with experiments on a flat bottom, the numerical results with dynamic correction show better accuracy in the simulation of ship-induced waves and wave resistance than those obtained using a static pressure distribution. The correlation coefficient for wake waves between the numerical and experimental results is improved by approximately 0.25 with the dynamic correction strategy. The amplitude and wavelength of ship-induced mini-tsunamis over a variable topography are found to be reduced when employing a dynamic correction compared with a static pressure distribution, and this effect becomes more pronounced with higher Froude number. The static pressure approach is shown to allow large deformations of the desired hull shape and changes in ship volume which are responsible for the different wave patterns from the two approaches.

In the question put forward by Scott et al., implications about the role of immune activation in depressive or other mood disorders were suggested. Low-level inflammation, triggered by the release of inflammatory molecules such as cytokines, has been detected in individuals with major mood disorders. These markers can be present in very low concentrations, posing a significant analytical challenge and complicating their use as reliable biomarkers. In this Perspective, we discuss the potential promise in leveraging nanotechnology and trace-level analysis of biomarkers of immune activation to enhance our molecular understanding of the immune system’s functioning and its association with depressive and other mood disorders. This Perspective critically discusses the analytical challenges of trace biomarker detection, highlighting issues with variability in study methodologies and cohort heterogeneity and emphasising the need for diurnal and longitudinal sampling to study circadian disruption and immune activation. Profiling inflammatory markers in this manner could create individualised molecular fingerprints, revealing disruptions in immune synchronisation with circadian rhythms and detecting abnormalities linked to specific mood disorder subtypes, and particularly ‘circadian depression’. As the profiling of general inflammatory markers may not be sufficient to study any causative relationship between immune activation and major mood disorders, we propose the exploration of novel biomarkers such as extracellular vesicles to support these investigations. The use of nanotechnologies for trace profiling of diurnal variations of inflammatory molecules, in combination with novel biomarkers, offers a promising strategy to develop a molecular understanding of the role of immune activation in depressive and other mood disorders.

This study documents several correlations observed during the first run of the plasma wakefield acceleration experiment E300 conducted at FACET-II, using a single drive electron bunch. The established correlations include those between the measured maximum energy loss of the drive electron beam and the integrated betatron X-ray signal, the calculated total beam energy deposited in the plasma and the integrated X-ray signal, among three visible light emission measuring cameras and between the visible plasma light and X-ray signal. The integrated X-ray signal correlates almost linearly with both the maximum energy loss of the drive beam and the energy deposited into the plasma, demonstrating its usability as a measure of energy transfer from the drive beam to the plasma. Visible plasma light is found to be a useful indicator of the presence of a wake at three locations that overall are two metres apart. Despite the complex dynamics and vastly different time scales, the X-ray radiation from the drive bunch and visible light emission from the plasma may prove to be effective non-invasive diagnostics for monitoring the energy transfer from the beam to the plasma in future high-repetition-rate experiments.

Syphilis remains a serious public health problem in mainland China that requires attention, modelling to describe and predict its prevalence patterns can help the government to develop more scientific interventions. The seasonal autoregressive integrated moving average (SARIMA) model, long short-term memory network (LSTM) model, hybrid SARIMA-LSTM model, and hybrid SARIMA-nonlinear auto-regressive models with exogenous inputs (SARIMA-NARX) model were used to simulate the time series data of the syphilis incidence from January 2004 to November 2023 respectively. Compared to the SARIMA, LSTM, and SARIMA-LSTM models, the median absolute deviation (MAD) value of the SARIMA-NARX model decreases by 352.69%, 4.98%, and 3.73%, respectively. The mean absolute percentage error (MAPE) value decreases by 73.7%, 23.46%, and 13.06%, respectively. The root mean square error (RMSE) value decreases by 68.02%, 26.68%, and 23.78%, respectively. The mean absolute error (MAE) value decreases by 70.90%, 23.00%, and 21.80%, respectively. The hybrid SARIMA-NARX and SARIMA-LSTM methods predict syphilis cases more accurately than the basic SARIMA and LSTM methods, so that can be used for governments to develop long-term syphilis prevention and control programs. In addition, the predicted cases still maintain a fairly high level of incidence, so there is an urgent need to develop more comprehensive prevention strategies.

The status of the genera Euparagonimus Chen, 1963 and Pagumogonimus Chen, 1963 relative to Paragonimus Braun, 1899 was investigated using DNA sequences from the mitochondrial cytochrome c oxidase subunit I (CO1) gene (partial) and the nuclear ribosomal DNA second internal transcribed spacer (ITS2). In the phylogenetic trees constructed, the genus Pagumogonimus is clearly not monophyletic and therefore not a natural taxon. Indeed, the type species of Pagumogonimus,P. skrjabini from China, is very closely related to Paragonimus miyazakii from Japan. The status of Euparagonimus is less obvious. Euparagonimus cenocopiosus lies distant from other lungflukes included in the analysis. It can be placed as sister to Paragonimus in some analyses and falls within the genus in others. A recently published morphological study placed E. cenocopiosus within the genus Paragonimus and probably this is where it should remain.

Brick-red deposits with palygorskite (Pal) as the main ingredient are widely distributed in nature, but these have not been deployed at a large scale in industry because of their inherent deep colors. In the present study, the brick-red Pal deposit was treated hydrothermally in various reaction media including water, a urea solution, and a thiourea solution. The effects of these processes on the structure, physicochemical features, and color of Pal were studied intensively to understand the structure and composition of the brick-red Pal deposit and to lay a theoretical foundation for the extension of its industrial application. The changes in structural features after hydrothermal treatment were studied by Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, magic-angle spinning nuclear magnetic resonance, and Mössbauer spectroscopy techniques. The results indicated that the color of brick-red Pal did not change after hydrothermal treatment in water or in a urea solution, and the color changed to gray-white after treatment in the thiourea solution. The rod-like crystal morphology of Pal was retained throughout the experiments and no significant change in the main associated minerals, including feldspar, muscovite, and quartz, was observed after hydrothermal treatment. The dissolution of associated hematite (α-Fe2O3 and the reduction of Fe(III) species are the main reason for the change of Pal from brick-red to gray-white.

The nanoscale elastic properties of moist clay minerals are not sufficiently understood. The aim of the present study was to understand the fundamental mechanism for the effects of water and pore size on clay mineral (K+-smectite) elastic properties using the General Utility Lattice Program (GULP) with the minimum energy configurations obtained from molecular dynamics (MD) simulations. The simulation results were compared to an ideal configuration with transversely isotropic symmetry and were found to be reasonably close. The pressures computed from the MD simulations indicated that the changes due to water in comparison to the dry state varied with the water content and pore size. For pore sizes of around 0.8–1.0 nm, the system goes through a process where the normal pressure is decreased and reaches a minimum as the water content is increased. The minimum normal pressure occurs at water contents of 8 wt.% and 15 wt.% for pore sizes of around 0.8 nm and 1 nm, respectively. Further analyses of the interaction energies between water and K+-smectite and between water and water revealed that the minimum normal pressure corresponded to the maximum rate of slope change of the interaction energies (the second derivative of the interaction energies with respect to the water content). The results indicated that in the presence of water the in-plane stiffness parameters were more correlated to the pressure change that resulted from the interplay between the interactions of water with K+-smectite and the interactions of water with water rather than the water content. The in-plane stiffness parameters were much higher than the out-of-plane parameters. Elastic wave velocities for the P and S waves (VP and VS) in the dry K+-smectite with a pore size of ~1 nm were calculated to be 7.5 and 4.1 km/s, respectively. The P and S wave velocity ratio is key in the interpretation of seismic behavior and revealed that VP/VS = 1.64–1.83, which were values in favorable agreement with the experimental data. The results might offer insight into seismic research to predict the mechanical properties of minerals that are difficult to obtain experimentally and can provide complimentary information to interpret seismic surveys that can assist gas and oil exploration.

The poor environmental stability of natural anthocyanin hinders its usefulness in various functional applications. The objectives of the present study were to enhance the environmental stability of anthocyanin extracted from Lycium ruthenicum by mixing it with montmorillonite to form an organic/inorganic hybrid pigment, and then to synthesize allochroic biodegradable composite films by incorporating the hybrid pigment into sodium alginate and test them for potential applications in food testing and packaging. The results of X-ray diffraction, Fourier-transform infrared spectroscopy, and use of the Brunauer–Emmett–Teller method and zeta potential demonstrated that anthocyanin was both adsorbed on the surface and intercalated into the interlayer of montmorillonite via host–guest interaction, and the hybrid pigments obtained allowed good, reversible, acid/base behavior after exposure to HCl and NH3 atmospheres. The composite films containing hybrid pigments had good mechanical properties due to the uniform dispersion of the pigments in a sodium alginate substrate and the formation of hydrogen bonds between them. Interestingly, the composite films also exhibited reversible acidichromism. The as-prepared hybrid pigments in composite films could, therefore, serve simultaneously as a reinforced material and as a smart coloring agent for a polymer substrate.

The effects of apparatus-induced dispersion on nonuniform, density-dependent flow in a cylindrical soil column were investigated using a finite-element model. To validate the model, the results with an analytical solution and laboratory column test data were analysed. The model simulations confirmed that flow nonuniformities induced by the apparatus are dissipated within the column when the distance to the apparatus outlet exceeds $3R/2$, where R represents the radius of the cylindrical column. Furthermore, the simulations revealed that convergent flow in the vicinity of the outlet introduces additional hydrodynamic dispersion in the soil column apparatus. However, this effect is minimal in the region where the column height exceeds $3R/2$. Additionally, it is found that an increase in the solution density gradient during the solute breakthrough period led to a decrease in flow velocity, which stabilized the flow and ultimately reduced dispersive mixing. Overall, this study provides insights into the behaviour of apparatus-induced dispersion in nonuniform, density-dependent flow within a cylindrical soil column, shedding light on the dynamics and mitigation of flow nonuniformities and dispersive mixing phenomena.

Competition among the two-plasmon decay (TPD) of backscattered light of stimulated Raman scattering (SRS), filamentation of the electron-plasma wave (EPW) and forward side SRS is investigated by two-dimensional particle-in-cell simulations. Our previous work [K. Q. Pan et al., Nucl. Fusion 58, 096035 (2018)] showed that in a plasma with the density near 1/10 of the critical density, the backscattered light would excite the TPD, which results in suppression of the backward SRS. However, this work further shows that when the laser intensity is so high ($>{10}^{16}$ W/cm2) that the backward SRS cannot be totally suppressed, filamentation of the EPW and forward side SRS will be excited. Then the TPD of the backscattered light only occurs in the early stage and is suppressed in the latter stage. Electron distribution functions further show that trapped-particle-modulation instability should be responsible for filamentation of the EPW. This research can promote the understanding of hot-electron generation and SRS saturation in inertial confinement fusion experiments.