作者机构：
[Dewen Tang] School of Mechanical Engineering, University of South China, Hengyang, China;Spallation Neutron Source Science Center, Dongguan, China;[Quan Ji] Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, China;[Chang Shu] School of Mechanical Engineering, University of South China, Hengyang, China<&wdkj&>Spallation Neutron Source Science Center, Dongguan, China;[Junsong Zhang] Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, China<&wdkj&>Spallation Neutron Source Science Center, Dongguan, China
通讯机构：
[Junsong Zhang] I;Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, China<&wdkj&>Spallation Neutron Source Science Center, Dongguan, China
摘要：
Design the sextupole precision mover for the Southern Advanced Photon Source that has requirements exceeding commercially available machines. The design of the mover has been verified to meet the requirements through a combination of static and dynamic simulations using ANSYS software, as well as relevant experimental testing. The mover we constructed has an absolute positioning error of 2 and 3 µm, a maximum inclination angle of 1.55″ and 5.67″ in the horizontal and vertical motion directions respectively under a 400 kg load. Its vibration force transmission rate is 1.065. The mover utilizes a non-coupled structure consisting of four layers of stainless steel plates, which exhibits good manufacturability. It is capable of achieving high precision and stability under a 400 kg load, meeting the requirements.
摘要：
Diffusion study of the Ni-Si-V system is significant for the establishment of kinetic database of Ni-based alloys. In this work, the diffusion couple experiment combined with the numerical inverse method was adopted to evaluate the diffusivities and atomic mobilities for the Ni-Si-V fcc phase with high throughput. We prepared 12 fcc Ni-Si-V diffusion couples, which were annealed at 1273, 1373 and 1473 K, and their composition profiles after annealing were then measured by EPMA (Electron Probe Microanalysis). Subsequently, inputting the measured composition profiles as well as the available thermodynamic descriptions into the numerical inverse method incorporated in the CALTPP (CALculation of ThermoPhysical Properties) software, the composition- and temperature-dependent diffusivities and atomic mobilities for the Ni-Si-V fcc phase were simultaneously evaluated. In order to verify the reliability of the present evaluations, the CALTPP-simulated diffusion behaviors such as composition profiles and diffusion paths were compared with the measured ones, demonstrating reasonable agreements with each other. Meanwhile, the high-throughput determinations of diffusivities were confirmed by the ones obtained by the Matano-Kirkaldy method. Furthermore, applying the presently obtained diffusivities and atomic mobilities in combination with thermodynamic descriptions of the Ni-Si-V fcc phase, their diffusion flux, two-dimensional composition profile, activation energy and pre-frequency factor were predicted. It is expected that the presently obtained diffusivities and atomic mobilities of the Ni-Si-V fcc phase can contribute to the establishment of kinetic database of Ni-based alloys for their high-efficiency material design.
通讯机构：
[Xu, SL ] U;Univ South China, Sch Resource Environm & Safety Engn, 28,West Changsheng Rd, Hengyang 421001, Peoples R China.;Univ South China, Prov Key Lab Emergency Safety Technol & Equipment, Hengyang 421001, Peoples R China.
关键词：
robot;radiation;reinforcement;gamma-ray;superMC;control and sensing systems
摘要：
This study investigates the radiation damage and radiation reinforcement of the control and sensing systems of nuclear robots. Radiation experiments were conducted on key electronic devices to study their radiation resistance, and a shielding structure for radiation reinforcement was designed to meet the radiation resistance performance requirements of the system. The results show that at doses exceeding 1300 Gy, Hall sensors, pressure transducers, and temperature transducers exhibit radiation damage. At doses exceeding 170 Gy, transformers and controllers also show radiation damage. Lithium batteries remain largely unaffected, but packs experience voltage decline. When using Pb and W as shielding materials for Super MC simulation, it was found that at a thickness of 15 mm, the shielding efficiency of the controller and transformer under Pb shielding increased by approximately 84.99% and 52.00%, respectively, compared to 92.23% and 74.47% under W, which had the best shielding effect benefits. By adopting radiation-resistant shielding reinforcement, we can effectively improve the radiation resistance of the controller and transformer. This is crucial for ensuring the reliable operation of nuclear robots in high-radiation environments and providing important data and theoretical support for the development of related technologies.
通讯机构：
[Tang, DW ] U;Univ South China, Sch Mech Engn, Hengyang 421001, Hunan, Peoples R China.
摘要：
<jats:p>Carbon/polymer-based flexible electrothermal films, as a Joule heating material with excellent electrothermal properties, good formability, and lightweight, are a very needed material in aircraft wing de-icing systems, flexible electric heating elements, and low-voltage wearable devices. In this study, a series of flexible electrically heated films were successfully prepared using polyimide (PI) as the film-forming substrate and graphene (GE) as the conductive filler. The effects of graphene content on the morphology, microstructure, and electrothermal properties, as well as the mechanical flexibility of the electrothermal films, were systematically investigated. The results showed that the GE/PI electrothermal films not only retained the good electrical conductivity of graphene but also had the excellent mechanical properties and high heat resistance of polyimide. The electric heating film with the addition of 8 wt. % GE can quickly reach 390 °C at 24V with uniform temperature distribution, and the mass loss at 500 °C is only 0.98 wt. %. A wide range of applications exist in fields such as flexible electric heating elements.</jats:p>
作者机构：
[Tang, Dewen; Qian, Jian] Univ South China, Sch Mech Engn, Hengyang 421001, Peoples R China.
通讯机构：
[Tang, DW ] U;Univ South China, Sch Mech Engn, Hengyang 421001, Peoples R China.
关键词：
point cloud registration;deep learning;attention mechanism
摘要：
The problem of registering point clouds in scenarios with low overlap is explored in this study. Previous methodologies depended on having a sufficient number of repeatable keypoints to extract correspondences, making them less effective in partially overlapping environments. In this paper, a novel learning network is proposed to optimize correspondences in sparse keypoints. Firstly, a multi-layer channel sampling mechanism is suggested to enhance the information in point clouds, and keypoints were filtered and fused at multi-layer resolutions to form patches through feature weight filtering. Moreover, a template matching module is devised, comprising a self-attention mapping convolutional neural network and a cross-attention network. This module aims to match contextual features and refine the correspondence in overlapping areas of patches, ultimately enhancing correspondence accuracy. Experimental results demonstrate the robustness of our model across various datasets, including ModelNet40, 3DMatch, 3DLoMatch, and KITTI. Notably, our method excels in low-overlap scenarios, showcasing superior performance.
作者机构：
[Tang, Dewen; Che, Zhiyuan; Jiang, Rui] Univ South China, Sch Mech Engn, Hengyang 412000, Hunan, Peoples R China.;[Tang, Dewen; Che, Zhiyuan; Jiang, Rui] Univ South China, Key Lab Nucl Facil Emergency Safety Technol & Equi, Hengyang 412000, Hunan, Peoples R China.
通讯机构：
[Tang, DW ] U;Univ South China, Sch Mech Engn, Hengyang 412000, Hunan, Peoples R China.;Univ South China, Key Lab Nucl Facil Emergency Safety Technol & Equi, Hengyang 412000, Hunan, Peoples R China.
摘要：
To investigate the effect of different oxidation times on the oxidation behavior of Zr-Sn-Nb alloy in a high-temperature steam environment at 1250 degree celsius, steam oxidation tests were conducted on the Zr-Sn-Nb alloy at 1250 degree celsius for durations ranging from 100 to 5000 s. Microstructural and elemental composition analyses of the Zr-Sn-Nb alloy were carried out using scanning electron microscopy, energy-dispersive x-ray spectroscopy, and optical microscopy. The results showed that in the initial stages of oxidation (0-1000 s), the weight gain per unit area followed a parabolic trend. After 2500 s of oxidation, the weight gain rate significantly increased. In the later stages of oxidation (after 4000 s), the weight gain curve transitioned from a parabolic shape to a linear law. With increasing oxidation time, the thickness of the oxide layer gradually increased. In the early stages (0-2500 s), the growth rate of the oxide layer thickness was relatively slow, but the appearance of micro-pores and cracks was observed. However, after 2500 s, the steam oxidation rate of the Zr-Sn-Nb alloy significantly accelerated, leading to fracture and failure of the alloy specimens. The change in oxide layer thickness over time followed a parabolic law before 2500 s and a linear law after 2500 s. The growth curve of the alpha-Zr(O) layer within 5000 s also followed a parabolic law.
