Cellulose nanocrystal thermal smart molecular brushes with upper critical aggregation temperature.

Grafting thermo-responsive polymers onto cellulose nanocrystals (CNCs) and achieving critical temperature regulation has drawn significant research interest. The thermal transition behavior of CNCs can be controlled by adjusting the polymer molecular brushes on the CNCs surface. We synthesized poly((2-dimethylamino) ethyl methacrylate) (PDMAEMA) grafted CNCs via surface-initiated reversible addition-fragmentation chain transfer, followed by modifying PDMAEMA brushes into poly-3-dimethyl(methacryloyloxyethyl) ammonium propane sulfonate (PDMAPS) brushes via quaternization.

Self-Assembly of a 3D Hollow BiOBr@Bi-MOF Heterostructure with Enhanced Photocatalytic Degradation of Dyes.

Considering the flexibility, adjustable pore structure, and abundant active sites of metal-organic frameworks (MOFs), rational design and fine control of the MOF-based hetero-nanocrystals is a highly important and challenging subject. In this work, self-assembly of a 3D hollow BiOBr@Bi-MOF microsphere was fabricated through precisely controlled dissociation kinetics of the self-sacrificial template (BiOBr) for the first time, where the residual quantity of BiOBr and the formation of Bi-MOF were carefully regulated by changing the reaction time and the capability of coordination. Meanwhile, the hollow microstructure was formed in BiOBr@Bi-MOF through the Oswald ripening mechanism to separate photogenerated electron-hole pairs and increase the adsorption capacity of Bi-MOF for dyes, which significantly enhanced the photocatalytic degradation efficiency of RhB from 56.

Investigation of Damage Reduction When Dry-Drilling Aramid Fiber-Reinforced Plastics Based on a Three-Point Step Drill.

Aramid fiber-reinforced plastic (AFRP) is widely used in bullet-proof and armor structures, and is difficult to drill because of the high-toughness aramid fibers with ductile fracturing-differently from carbon fiber. Therefore, drilling quality cannot be ensured by the drilling used for carbon fiber-reinforced plastic, and frequently, delamination and burrs occur in the drilling process. This article first established a two-dimensional cutting model for analyzing the fiber deformation and material interface cracking.

Improved separated-parameter calibration method for binocular vision measurements with a large field of view.

Large field-of-view (FOV) calibration is indispensable to ensure the accuracy of vision measurement systems for large aviation components. We propose an improved separated-parameter calibration method for large-FOV binocular vision measurements with a high flexibility and accuracy. Firstly, the camera parameters are separately calibrated according to the sub-area features of image.

A Knowledge-Driven Approach for 3D High Temporal-Spatial Measurement of an Arbitrary Contouring Error of CNC Machine Tools Using Monocular Vision.

Periodic health checks of contouring errors under unloaded conditions are critical for machine performance evaluation and value-added manufacturing. Aiming at breaking the dimension, range and speed measurement limitations of the existing devices, a cost-effective knowledge-driven approach for detecting error motions of arbitrary paths using a single camera is proposed. In combination with the PNP algorithm, the three-dimensional (3D) evaluation of large-scale contouring error in relatively high feed rate conditions can be deduced from a priori geometrical knowledge.

A Novel Vision-Based Pose Measurement Method Considering the Refraction of Light.

Nowadays, due to the advantages of non-contact and high-speed, vision-based pose measurements have been widely used for aircraft performance testing in a wind tunnel. However, usually glass ports are used to protect cameras against the high-speed airflow influence, which will lead to a big measurement error. In this paper, to further improve the vision-based pose measurement accuracy, an imaging model which considers the refraction light of the observation window was proposed.

Improved camera calibration method based on perpendicularity compensation for binocular stereo vision measurement system.

High-precision calibration of binocular vision systems plays an important role in accurate dimensional measurements. In this paper, an improved camera calibration method is proposed. First, an accurate intrinsic parameters calibration method based on active vision with perpendicularity compensation is developed.