Beihang University

Predictive Opportunistic Maintenance for k-out-of-n Systems with Heterogeneous Two-Stage Degradation

Predictive opportunistic maintenance can improve maintenance coordination in multi-component systems by jointly exploiting health information and shared maintenance opportunities. However, redundancy and component heterogeneity complicate maintenance timing and component selectio...

On the consistent similarity of equilibrium supersonic pressure-gradient turbulent boundary layers over smooth and rough walls

The consistent outer-layer similarity of equilibrium supersonic pressure-gradient turbulent boundary layers (PGTBLs) over smooth and rough walls, which has not been systematically explored for rough-wall configurations, is investigated using a unified similarity theory and direct...

Ventilation and heat exchange characteristics in aircraft cabin considering buoyancy-driven flow and pressure-induced variations

During flight, aerodynamic heating and multiple internal heat loads create a high-temperature low-pressure extreme environment. The flow and heat transfer mechanisms there differ from those in atmospheric sealed chambers, posing substantial challenges to thermal control design. M...

Wildfire exposure and political participation in Africa

Abstract Civic engagement can shape collective responses to climate change. However, evidence on how climate-related disasters affect political participation in Africa remains limited. Combining Global Fire Atlas records with Afrobarometer surveys of more than 100,000 people in 3...

Research on Multi-Point large strain measurement sensors based on flexible thin Films and fiber Bragg Gratings

To achieve highly sensitive distributed measurement of large strains, this paper proposes a surface-attached FBG array sensor based on a flexible PDMS/SiO 2 substrate. The sensor structure is designed, and a finite element model of the flexible thin-film substrate and the S-shape...

Hierarchical Assembly of Sub‐2 nm Amorphous Nanobelt Membranes for Oil–Water Separation via Pore Engineering

ABSTRACT The trade‐off between flux and selectivity in oil–water separation membrane fundamentally originates from a structural incompatibility between interconnected transport pathways and densely distributed interfacial active sites. Herein, we construct a free‐standing membran...

Quasi-isotropic phase modulator architecture based on thin-film lithium niobate

In this study, a quasi-isotropic phase modulator operating in the C-band is fabricated and verified to address polarization-dependent mode constraints and the imbalance of electro-optic modulation efficiency in a thin-film lithium-niobate photonic platform. By integrating an adia...

Fluid–Structure Interaction Simulation of a Supersonic Reefed Parachute Cluster During the Inflation Process

To investigate the multi-stage inflation mechanism of a supersonic reefed parachute cluster, an ALE-based fluid–structure interaction method is applied. The canopy permeability is modeled using the Ergun equation, and the virtual structure contact method is employed to handle con...

Chamber-to-Field Development and Validation of Integrated Filtration–Adsorption Air Cleaners for Particle and VOC Control in Shipboard Cabins

Shipboard cabins can contain both oil mist-dominated particulate matter and volatile organic compounds (VOCs), creating a need for compact air-cleaning systems capable of simultaneous particle and gas-phase removal. This study developed an integrated filtration–adsorption air cle...

Flow-Induced Deviation Mechanism and Structural Optimization of Engine Valves Under Braking Conditions

Under braking conditions, the valve is prone to lateral swing, which significantly compromises engine performance and longevity. Research indicates that the asymmetric vortex structures around the valve are one of the primary factors inducing effects such as lateral swing. Theref...

High-dimensional inverse design enables multiple synthesis routes to prescribed carbon nanotube array descriptors

Abstract Prescribed synthesis of carbon nanotube (CNT) arrays remains challenging because multiple processing stages jointly regulate array height (H), density (ρ), and orientational order (HOF), creating a nonlinear and non-unique relationship between structural targets and synt...

Bifunctional Tetramethylammonium Acetate Modifier Synchronizes Defect Passivation and Energy-Level Alignment for HTL-Free Carbon-Based Inorganic Perovskite Solar Cells

Abstract Carbon-based HTL-free CsPbI2.75Br0.25 all-inorganic perovskite solar cells face challenges from interfacial defects and suboptimal energy-level alignment. In this work, tetramethylammonium acetate (TMMAc) is employed for the first time as a multifunctional surface modifi...

A Change Detection Network for Heterogeneous Remote Sensing Images Based on Decoupled Differential Architecture Search

With the advancement of Earth observation technology and the improvement of multisource data acquisition capabilities, heterogeneous remote sensing image change detection technology has become increasingly important. However, existing heterogeneous remote sensing image change det...

The Effects of Hollow Fiber Membrane Configuration on Hemodynamic Characteristics, Oxygen Transfer Performance and Thrombosis Risk in Oxygenators: A Numerical Research

ABSTRACT Background The effects of hollow fiber membrane (HFM) configuration on hemodynamic characteristics, oxygen transfer performance, and thrombosis risk in oxygenators are not clear, and the present study was accomplished to investigate these effects. Methods Three micro‐sca...

Enhanced Fog Harvesting via Synergistic Regulation of the Entire Process on a Multi-Bioinspired Patterned Surface

Freshwater scarcity has become an urgent global issue. Bioinspired fog harvesting is a promising route to freshwater supply, whereas conventional bioinspired surfaces merely optimize partial procedures independently, severely restricting fog harvesting efficiency. Herein, inspire...

Physics filtering favors the generalization of robot learning

Abstract Living organisms exhibit extraordinary adaptability to unseen environments through their intrinsic physical structures and lifelong feedback-driven learning. Endowing robots with comparable generalization is critical for reliable operation in the real world. While recent...

Eigenvalue Analysis Method for Liner Noise Reduction Under Multiradial-Mode Incidence

Engine fan noise contains multiple radial modes, and the transmission loss (TL) of acoustic liners in such cases is influenced by both the power ratio among these radial modes and the phase difference between them. The objective of this paper is to develop a method for the rapid...

Identification of a nanosecond isomer of $$^{164}$$Tb

Abstract This letter reports on the identification of a new isomeric state of $$^{164}$$ 164 Tb ( $$Z=65$$ Z = 65 , $$N=99$$ N = 99 ), which was measured with the DESPEC setup at the GSI Helmholtzzentrum für Schwerionenforschung GmbH following the first relativistic fragmentation...

The illusion of clinical reasoning: a benchmark reveals the pervasive gap in vision-language models for clinical competency

The rapid integration of foundation models into clinical practice and their use for public health inquiries necessitates a rigorous evaluation of their true clinical reasoning capabilities, which extends beyond success on narrow examinations. Current benchmarks, often based on me...

Scaling of Urban 3D Form with Emissions and GDP in Chinese Cities

Abstract Rapid urbanization has permanently transformed the face of cities. As the physical manifestation of these transformations, urban form provides a key basis for examining its connections with urban outcomes. While previous studies have primarily focused on two-dimensional...