AIR-DA: Adversarial Image Reconstruction for Unsupervised Domain Adaptive Object Detection

Unsupervised domain adaptive object detection is a challenging vision task where object detectors are adapted from a label-rich source domain to an unlabeled target domain. Recent advances prove the efficacy of the adversarial based domain alignment where the adversarial training between the feature extractor and domain discriminator results in domain-invariance in the feature space. However, due to the domain shift, domain discrimination, especially on low-level features, is an easy task. This results in an imbalance of the adversarial training between the domain discriminator and the feature extractor. In this work, we achieve a better domain alignment by introducing an auxiliary regularization task to improve the training balance. Specifically, we propose Adversarial Image Reconstruction (AIR) as the regularizer to facilitate the adversarial training of the feature extractor. We further design a multi-level feature alignment module to enhance the adaptation performance. Our evaluations across several datasets of challenging domain shifts demonstrate that the proposed method outperforms all previous methods, of both one- and two-stage, in most settings.Comment: Accepted at IEEE Robotics and Automation Letters 202

Research on forming method of additive manufacturing of frozen sand mold

In order to promote the green and sustainable development of the foundry industry, it is necessary to further explore new methods and technologies for green foundry. This paper innovatively proposes a method of additive manufacturing of frozen sand mold, using water as the binder instead of resin binders for additive manufacturing in low-temperature environments, which effectively solves the problems of harmful gas emissions during the pouring process and the difficulty of direct recycling of molding sand, and realizes high-performance green casting of complex castings. In this paper, the liquid-solid phase transition mechanism of the binder for additive manufacturing of frozen sand mold and the change law of the normal temperature field and phase transition field of the pre-cooled powder bed porous medium at different temperatures are studied, and the process window of additive manufacturing of frozen sand mold is obtained, which provides a new green casting method for the foundry field

Inhibition of Hydrogen Evolution by a Bifunctional Membrane between Anode and Electrolyte of Aluminum–Air Battery

The hydrogen evolution reaction of the anode is a severe barrier that limits the further commercial application of Al–air batteries. Therefore, this study introduces a bifunctional membrane for the inhibition of hydrogen evolution in Al–air batteries. The reference to Al2O3@PAN as “bifunctional” means that it has both hydrophobic and anti-corrosion functions. Al2O3 can effectively inhibit the migration of hydroxide ions, and PAN is an excellent hydrophobic material. The bifunctional membrane is placed between the aluminum anode and the electrolyte, which can prevent the invasion of excess water and hydroxide ions, thereby inhibiting the hydrogen evolution corrosion of the anode. Electrochemical tests have confirmed that the corrosion inhibition rate of a bifunctional membrane containing 1.82 wt. % Al2O3@PAN is as high as 89.24%. The specific capacity of Al–air batteries containing this membrane can reach 1950 mAh/g, and the utilization rate of the aluminum anode has reached 61.2%, which is helpful in reducing the waste of aluminum resources. The results prove that the bifunctional membrane has excellent anti-corrosion properties. Bifunctional membranes can also be used to prevent the corrosion of metals in other fields

Inhibition of Hydrogen Evolution by a Bifunctional Membrane between Anode and Electrolyte of Aluminum–Air Battery

The hydrogen evolution reaction of the anode is a severe barrier that limits the further commercial application of Al–air batteries. Therefore, this study introduces a bifunctional membrane for the inhibition of hydrogen evolution in Al–air batteries. The reference to Al2O3@PAN as “bifunctional” means that it has both hydrophobic and anti-corrosion functions. Al2O3 can effectively inhibit the migration of hydroxide ions, and PAN is an excellent hydrophobic material. The bifunctional membrane is placed between the aluminum anode and the electrolyte, which can prevent the invasion of excess water and hydroxide ions, thereby inhibiting the hydrogen evolution corrosion of the anode. Electrochemical tests have confirmed that the corrosion inhibition rate of a bifunctional membrane containing 1.82 wt. % Al2O3@PAN is as high as 89.24%. The specific capacity of Al–air batteries containing this membrane can reach 1950 mAh/g, and the utilization rate of the aluminum anode has reached 61.2%, which is helpful in reducing the waste of aluminum resources. The results prove that the bifunctional membrane has excellent anti-corrosion properties. Bifunctional membranes can also be used to prevent the corrosion of metals in other fields

Composite Anion Exchange Membrane from Quaternized Polymer Spheres with Tunable and Enhanced Hydroxide Conduction Property

In this research, novel quaternized polymer spheres (QPSs) with a high quaternary ammonium (QA) group loading amount and a controllable structure are synthesized and incorporated into a chitosan (CS) matrix to fabricate a composite membrane. Systematic characterizations and molecular simulation are adopted to elaborate the relationship between the QA structure of QPSs and physical-chemical as well as ion conduction properties of composite membranes. The well-dispersed QPSs generate repulsive interaction to CS chains, endowing the composite membrane with promoted chain mobility and water uptake and thereby enhanced hydroxide conductivity. The QPSs work as hydroxide conductors within the membranes, affording a hydroxide conductivity increase over 80%. As the hopping sites in the membrane, the QA group with moderate OH^– combination/dissociation capability exhibits higher OH^– conductivity. By comparison, the QA group with the highest or lowest potential displays slightly lower OH^– conductivity. Besides, extending the chain length of the QA ligand generates obvious steric hindrance and then impedes OH^– combination