A Bio-Inspired Drag Reduction Method of Bionic Fish Skin Mucus Structure.

Efforts to enhance the speed and reduce the energy consumption of underwater vehicles have led to the proposal of a novel mucus release structure inspired by the secretion of mucus cells on fish skin. This structure features interconnected microgrooves with excellent flexibility for adjusting to different states, effectively reducing drag through mucus release. Numerical analysis of the drag reduction performance of the mucous-releasing micro-pore structure was conducted using ANSYS Fluent 19.

Change Point Detection for Fine-Grained MFR Work Modes with Multi-Head Attention-Based Bi-LSTM Network.

Detection of the changes in Multi-Functional Radar (MFR) work modes is a critical situation assessment task for Electronic Support Measure (ESM) systems. There are two major challenges that must be addressed: (i) The received radar pulse stream may contain multiple work mode segments of unknown number and duration, which makes the Change Point Detection (CPD) difficult. (ii) Modern MFRs can produce a variety of parameter-level (fine-grained) work modes with complex and flexible patterns, which are challenging to detect through traditional statistical methods and basic learning models.

Planar diffractive grating for magneto-optical trap application: fabrication and testing.

The design, fabrication, and demonstration of a planar two-dimensional-crossed reflective diffractive grating are proposed to construct a novel optical configuration, to the best of our knowledge, potentially applied for atom cooling and trapping in a magneto-optical trap. Based on the proposed single-beam single-exposure scheme by means of an orthogonal two-axis Lloyd's mirrors interferometer, we rapidly patterned a ∼1µ period grating capable of providing a uniform intensity of the diffracted beams. The key structural parameters of the grating including the array square hole's width and depth were determined, aiming at providing a high energy of the diffracted beams to perform the atom cooling and trapping.

Polarized holographic lithography system for high-uniformity microscale patterning with periodic tunability.

Periodic microscale array structures play an important role in diverse applications involving photonic crystals and diffraction gratings. A polarized holographic lithography system is proposed for patterning high-uniformity microscale two-dimensional crossed-grating structures with periodic tunability. Orthogonal two-axis Lloyd's mirror interference and polarization modulation produce three sub-beams, enabling the formation of two-dimensional crossed-grating patterns with wavelength-comparable periods by a single exposure.

Patterning nanoscale crossed grating with high uniformity by using two-axis Lloyd's mirrors based interference lithography.

A two-axis Lloyd's mirrors interferometer based optical fabrication system was theoretically investigated and constructed for patterning high-uniformity nanoscale crossed grating structures over a large area with a high throughput. The current interferometer was configured with two reflected mirrors and a grating holder, which are placed edge by edge and orthogonal with each other. In such a manner, the two beams reflected from the two mirrors interfere with the incident beam, respectively, forming a crossed grating patterns with only one exposure.