Multi-parametric bifurcations of a fractional neural network with multiple delays and inertial terms.

Effects of insecticides and awareness on the dynamics of a delayed malaria model: A real-data calibration.

In human-robot interaction, external force measurement is fundamental to achieving robot compliance control. Parameter identification based on robot dynamics enables external force detection without expensive sensors. However, the unmodeled dynamic errors inherent in real robots pose a challenge to force estimation accuracy. In addition, existing force estimation methods often suffer from high computational dimensionality and an excessive number of tuning parameters, which limits their generalizability and migration to other platforms. In this letter, we employ a Variational Approximate Gaussian Process Regression (VAGP) model to learn the robot's dynamic errors, capturing both the mean and covariance of the error. Then we introduced the indirect measurement form and proposed a dimension-reduced Kalman filter (DRKF) to simplify the state space equation. Finally, we propose a VAGP-based adaptive Kalman filter (VAGAKF) that utilizes the least squares method to reduce the number of tuning parameters. VAGAKF effectively separates external forces from dynamics model uncertainty, reducing reliance on highly accurate robot and external force models. VAGAKF reduces average RMSE and time delay by <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">${23.06\%}$</tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">${66.7\%}$</tex-math></inline-formula> respectively, relative to existing methods.

Inner synchronized stationary distribution of hybrid stochastic coupled systems with time delay

Physics informed neural network for inertia effect estimation in tunnel boring machine considering time delay

An enhanced meshless method using modified radial basis functions for nonlinear fractional partial integro-differential models with time delay

Voltage source converter (VSC) power balancing and voltage regulation are two critical and interrelated objectives for multi-terminal DC distribution networks (DCDNs). This paper proposes a distributed multi-objective control strategy for DCDNs based on linear quadratic (LQ) optimal control theory to achieve these objectives simultaneously. Unlike the conventional centralized control method, which is usually expensive in terms of communication and computation, our key technology is that the original nonlinear multi-objective control problem of DCDNs is converted into the LQ optimal control problem through the linear power flow sensitivity. A distributed optimal controller is presented based on an observer using the information of neighboring VSCs and is solved by the solution of an algebraic Riccati equation, which provides a faster convergence speed than conventional consensus-based algorithms. The proposed method enhances robustness by accounting for DCDN topology reconfigurations in the observer gain calculation. The proposed controller is tested on a ±10 kV four-terminal DCDN under communication failures, topology changes, and time delays. De tailed simulation studies and comparative analyses demonstrate the superior convergence performance and robustness of the proposed controller.

Phase competition in AlCoCrFeNi x high-entropy alloys ( x = 2.0, 2.1, 2.2, and 2.4) was investigated using synchrotron X-ray diffraction combined with electromagnetic levitation. In undercooled melts with x = 2.0, 2.1, and 2.2, the ordered B2 phase forms first via the transformation L → B2, marking the initial stage of solidification. This observation aligns well with the double recalescence phenomenon, where B2 crystallizes directly from the liquid, followed by the formation of a B2/A1 eutectic structure from the mushy zone, as captured in high-speed video recordings of the AlCoCrFeNi 2.1 sample. In contrast, the AlCoCrFeNi 2.4 alloy solidifies initially with the primary A1 phase via L → A1. The delay time (Δ t ) between nucleation of the primary phase and onset of eutectic transformation is strongly influenced by the nickel concentration. Moreover, the dissolution temperature of the ordered L1 2 phase during solid-state heating increases steadily with rising nickel content. These experimental findings show strong agreement with phase evolution predictions obtained through thermodynamic modeling of the AlCoCrFeNi system using Thermo-Calc software. Overall, this study provides a comprehensive picture of the phase formation and stability, solidification kinetics, and microstructural development of AlCoCrFeNi x high-entropy alloys.

Passive fluid flow is not sufficient to meet new analytical requirements, therefore further research is needed in the field of flow control in order to improve the application of microfluidic systems. In this work, stimuli-sensitive materials have been studied to act as barriers and repositories to be integrated in μPADs. Poly(N-isopropylacrylamide) (p-NIPAM) has been studied to act as a reservoir and flow retardant. As a reservoir, the swelling/de-swelling behaviour has been characterized as a function of temperature, kinetics, reservoir size and the influence of pH. As a flow retardant, a p-NIPAM ionogel was used to significantly slow down the flow and even stop it. This is very useful for preventing the mixing of reagents until a certain point in time or for controlling where the mixing occurs. The ionogel volume and the delay time were optimised. As proof of concept, they were used in a colorimetric μPAD for nitrite determination based on the Griess chemistry. The results demonstrate the feasibility of integrating the developed stimulus-sensitive materials in μPADs, enabling new applications where these tools are required. • Stimuli-responsive materials were studied and optimised to be used in μPADs. • The materials functioned effectively as barriers and repositories within μPAD systems. • A colorimetric μPAD was successfully fabricated for nitrite detection in water. • Results confirmed their potential for integration into μPAD-based applications.

A sensitive sentinel: Chironomus xanthus as a bioindicator of freshwater sediment quality in Southern Latin America.

Shipborne monitoring of significant wave height from BeiDou reflected signal considering satellite elevation and azimuth angles

Heave motion prediction with variational bayesian-based strong tracking Kalman filter

Flow rate determination in a two-phase system using radioactive particle tracking and deep learning.

Functional magnetic resonance imaging (fMRI) aims to identify biomarkers of neuropsychiatric illnesses, including substance use disorders; however, fMRI's clinical utility remains limited. One underexplored aspect of the fMRI signal is the systemic low-frequency oscillation (sLFO), a global physiological signal historically treated as noise but linked to vascular and autonomic function. Across 4 independent datasets, we used Regressor Interpolation at Progressive Time Delays analyses to extract the sLFO from resting-state and task-based fMRI data. We evaluated relationships between sLFO amplitude and acute and chronic indices of nicotine use. We further assessed the effects of nicotine and methylphenidate on the sLFO and related task performance. In individuals who smoked tobacco, higher average sLFO amplitude during cigarette cue exposure was negatively associated with nicotine dependence (n = 64; r = -0.32, p = .009), whereas a rise in the sLFO across the task was negatively associated with greater cue-induced craving (r = -0.31, p = .014). sLFO amplitude was reduced during chronic nicotine use versus abstinence (n = 65; p < .001). Relative to placebo, acute single-dose methylphenidate administration also reduced the sLFO in healthy control participants (n = 58; p = .001). Both acute methylphenidate- and nicotine-induced reductions in sLFO amplitude were associated with improved cognitive task performance. These findings demonstrate that the sLFO encodes biologically meaningful information related to substance use, consistent with its role as an index of physiological arousal. Importantly, because the sLFO can be extracted directly from existing fMRI datasets, it offers a powerful and complementary approach to enhance the clinical relevance of fMRI research beyond substance use.

The normal zone propagation velocity (NZPV) in high-temperature superconductors (HTS) is two to three orders of magnitude lower than that in low-temperature superconductors (LTS). This slow quench propagation poses a critical challenge for quench detection in HTS applications. Fiber Bragg Grating (FBG) sensors have demonstrated potential as cryogenic sensors for quench detection in HTS applications. But determining an appropriate threshold value for the central wavelength shift (Δλ) in quench detection remains a question to be addressed. In this paper, both single superconducting tapes and stacked tapes, which serve as the fundamental building blocks of HTS cables, are investigated. The time delay of the FBG sensor is demonstrated to be shorter than that of voltage taps when a hotspot occurs at the grating location. The Δλ corresponding to quench temperature—the threshold examined in this study—decreases as the distance from the hotspot increases. The FBG can effectively respond to a quench event more quickly than voltage, when the distance from the hot spot is less than 10 mm.

A Prospective Study of Stereotactic Body Radiation Therapy in Oligometastatic Renal Cell Carcinoma.

Ozone-affected auto-ignitive hydrogen-air flames: Transitions near critical temperatures

A sliding mode active disturbance rejection tracking control scheme based on the Smith predictive control structure is proposed for the front steering wheel of tractors, aiming to address the challenges of time delay and unknown disturbances in the angle tracking process. In the control system design, the effects of time delay and disturbances on the angle tracking performance are thoroughly considered, based on the established steering system model. A time delay processing structure is designed based on the Smith predictive control principle, and linear extended state observer is designed to realize synchronous estimation for the un-delayed angle output and the controller output. A simple Sliding Mode Controller (SMC) is introduced to replace the linear feedback controller in active disturbance rejection control (ADRC) to improve the accuracy and disturbance rejection performance. Simulation charts and performance evaluating indexes show that the proposed control method has obvious advantages in tracking accuracy, robustness and disturbance rejection in comparison with other methods. The angle tracking error is no more than 0.055rad even under the interference of white noise signal. The proposed method effectively mitigates the impact of time delay and disturbance, it can significantly enhance the dynamic response performance of the steering system.

BACKGROUND Perioperative hypothermia is a common complication of gastrointestinal surgery and is associated with an increased risk of surgical site infections and other complications. However, the relationship between comprehensive temperature management quality, including monitoring, protocol adherence, timely intervention, and postoperative infection outcomes, remains insufficiently studied, particularly in relation to surgical approach and patient comorbidities. AIM To investigate the impact and underlying pathophysiological mechanisms of perioperative temperature management nursing quality on postoperative infectious complications in patients undergoing gastrointestinal surgery. METHODS A retrospective analysis was conducted on 45 patients who underwent elective gastrointestinal surgery at our institution between 2020 and 2025: Nine patients with postoperative infections within 30 days and 36 uninfected controls. A temperature-management compliance score was constructed and conditional logistic regression analysis was used to analyze the risk of postoperative infection. The effect modification was assessed in subgroups stratified by surgical approach and diabetes status. Differences in the microcirculatory, metabolic, and inflammatory mechanism-related indicators were compared between groups. RESULTS The case group had significantly lower intraoperative and immediate postoperative body temperatures, intraoperative active warming use, and temperature management compliance score and a longer hypothermia duration than the control (P &lt; 0.05). The proportion of patients who underwent preoperative warming was not significantly different (P &gt; 0.05). Multivariate conditional logistic regression analysis revealed that “lowest intraoperative body temperature” and “temperature management compliance scores” were independent risk factors for postoperative infections (P &lt; 0.05). Surgical approach and diabetes status significantly affected the association between the lowest intraoperative body temperature and postoperative infection (P &lt; 0.05). The case group had significantly higher intraoperative core temperature variability, core-to-skin temperature gradient, postoperative serum interleukin-6 levels, temperature management response delay time, and intraoperative fraction of inspired oxygen exposure index (P &lt; 0.05), whereas intraoperative lactate clearance and immediate postoperative peripheral perfusion index were significantly lower (P &lt; 0.05). CONCLUSION Perioperative hypothermia and inadequate nursing quality for temperature management are independent risk factors for postoperative infections following gastrointestinal surgery. Enhanced temperature monitoring and active warming via standardized individualized temperature management protocols may reduce the risk of postoperative infection, especially in patients undergoing open surgery and those with diabetes.

Three-level Λ systems provide a versatile platform for quantum optical phenomena such as electromagnetically induced transparency (EIT), slow light, and quantum memory. Such Λ systems have been realized in several quantum hardware platforms, including atomic systems, superconducting artificial atoms, and meta-structures. Previous experiments involving superconducting artificial atoms incorporated coupling to additional degrees of freedom, such as resonators or other superconducting atoms. In this work, we performed an EIT experiment in the microwave frequency range utilizing a single fluxonium qubit within a microwave waveguide. The Λ system consists of two plasmon transitions in combination with one metastable state originating from the fluxon transition. In this configuration, the controlling and probing transitions are strongly coupled to the transmission line, safeguarding the transition between |0⟩ and |1⟩ states and ensuring the fluxonium qubit is close to the sweet spot. Our observations include the manifestation of EIT, a slowdown of light with a delay time of 217 ns, and photon storage. These results highlight the potential as a phase shifter or quantum memory for quantum communication in superconducting circuits.