检索结果-南通市图书馆

Research and development of a 0.5-m-long helical superconducting undulator prototype

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2024年第10期35卷 86-95页

作者： xiang-chen yang Xiao-Wu Yu Jun-Hao Wei xiang-Zhen Zhang Zi-Lin chen Xiao-Juan Bian He-Ting Li Guang-Yao Feng Yu-Hui Li National Synchrotron Radiation Laboratory University of Science and Technology of ChinaHefei 230029China Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China Institute of Plasma Physics Chinese Academy of Sciences(ASIPP)Hefei 230031China China Spallation Neutron Source Institute of High Energy PhysicsChinese Academy of SciencesDongguan 523000China

The helical undulator is in high demand in synchrotron radiation facilities for circular polarization *** to the higher field strength provided by the superconducting undulator compared to the conventional permanent-magnet undulator,greater research efforts should be directed toward this *** helical superconducting undulator holds great potential in synchrotron radiation facilities,especially in low-energy storage rings that seek circularly polarized radiation with the highest possible radiation *** the successful development of planar superconducting undulators,the Institute of High Energy Physics conducted research and development for the helical superconducting undulator.A 0.5-m-long Deltatype superconducting undulator prototype was developed and *** information on the design,fabrication,and cryogenic testing of the prototype is presented and discussed.

关键词： Helical Superconducting undulator Delta

Elevated-temperature tribological behavior of Ti–B–C–N coatings deposited by reactive magnetron sputtering

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2015年第12期34卷 838-843页

作者： xiang-yang chen Shao-Fu Huang Sheng-Li Ma Run Huang Jin Zhang Hai-Xia Hu School of Mechanical Engineering Anhui University of Science and Technology State Key Laboratory for Mechanical Behavior of Materials Xi’an Jiaotong University School of Materials Science and Engineering Anhui University of Science and Technology

Quaternary Ti–B–C–N coatings with various carbon contents were deposited on high-speed steel (HSS) substrates by reactive magnetron sputtering (RMS) system. The elevated-temperature tribological behavior of Ti–B–C–N coatings was explored using pin-on-disk tribometer, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). The present results show that the steady-state friction coefficient value and the instantaneous friction coefficient fluctuation range of Ti–B–C–N coatings decrease as carbon content increases at 100 and 300°C, while the steady-state friction coefficient value of all Ti–B–C–N coatings becomes higher than 0.4 at 500°C. As ambient temperature increases, the running-in periods of all Ti–B–C–N coatings become shorter. Wear damage to Ti–B–C–N coatings during sliding at elevated temperature is mainly caused by adhesive wear, and adhesive-wear damage to Ti–B–C–N coatings increases as ambient temperature increases; however, higher carbon content is beneficial for decreasing the adhesive-wear damage to Ti–B–C–N coatings during sliding at elevated temperature.

关键词： Tribological behavior Ti–B–C–N coatings Reactive magnetron sputtering Elevated temperature

Vacuum ammonia stripping from liquid digestate:Effects of pH,alkalinity,temperature,negative pressure and process optimization

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2025年第3期149卷 638-650页

作者： Qiuhong chen Donghai yang xiang chen Xiankai Wang Bin Dong Xiaohu Dai State Key Laboratory of Pollution Control and Resource Reuse College of Environmental Science and EngineeringTongji UniversityShanghai 200092China yangTZE Eco-Environment Engineering Research Center National Engineering Research Center of Eco-environment Protection for Yangtze River Economic BeltChina Three Gorges CorporationWuhan 430010China

High ammonia-nitrogen digestate has become a key bottleneck limiting the anaerobic digestion of organic solid *** ammonia stripping can simultaneously remove and recover ammonia nitrogen,which has attracted a lot of attention in recent *** investigate the parameter effects on the efficiency and mass transfer,five combination conditions(53℃ 15 kPa,60°C 20 kPa,65°C 25 kPa,72°C 35 kPa,and 81°C 50 kPa)were conducted for ammonia stripping of sludge *** results showed that 80%of ammonia nitrogen was stripped in 45 min for all experimental groups,but the ammonia transfer coefficient varied under different conditions,which increased with the rising of boiling point temperature,and reached the maximum value(39.0 mm/hr)at 81°C 50 *** ammonia nitrogen removal efficiency was more than 80%for 30 min vacuum stripping after adjusting the initial pH to above 9.5,and adjustment of the initial alkalinity also affects the pH value of liquid *** was found that pH and alkalinity are the key factors influencing the ammonia nitrogen dissociation and removal efficiency,while temperature and vacuum mainly affect the ammonia nitrogen mass transfer and removal *** terms of the mechanism of vacuum ammonia stripping,it underwent alkalinity destruction,pH enhancement,ammonia nitrogen dissociation,and free ammonia *** this study,two-stage experiments of alkalinity destruction and ammonia removal were also carried out,which showed that the two-stage configuration was beneficial for ammonia *** provides a theoretical basis and practical technology for the vacuum ammonia stripping from liquid digestate of organic solid waste.

关键词： Liquid digestate Vacuum ammonia stripping Alkalinity Mass transfer Process optimization

The superconducting magnet for ADS injection-I

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Radiation Detection Technology and Methods 2019年第1期3卷 8-12页

作者： xiang-chen yang Quan-ling Peng Da cheng Feng-yu Xu Yuan chen An-bin chen Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China Harbin Institute of Technology Harbin 150006HeilongjiangChina

Purpose As the world energetic demand is increasing day by day,the development of nuclear energy is of great ***,the development is followed by a lot of tough questions like the management and storage of the nuclear ***,which is short for the accelerator-driven sub-critical system,may be a good choice because it can provide an efficient transmutations of nuclear *** countries have carried out some research in related areas like the USA,Japan and *** superconducting magnet system The cryomodule I(CM1)for China’s ADS Injection-I had been designed,fabricated and online *** CM1 is mainly composed of superconducting spoke cavities,beam positionmonitors,cryogenic system and superconducting *** superconducting magnet system,which includes the magnet and current leads,is aimed at focusing and correcting the proton *** Seven superconducting magnets and current leads for CM1 are successfully designed and *** strength meets design specifications,the field meets the design demands,and the online test shows that the magnets can work in a rather stable *** this paper,the detailed design and installation of the superconducting magnets are presented.

关键词： CM1 Superconducting magnet Current leads

Superconducting multipole wiggler with large magnetic gap for HEPS-TF

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2022年第2期33卷 21-29页

作者： Xian-Jing Sun Fu-San chen xiang-chen yang Wan chen Xiao-Juan Bian Min-Xian Li Rui Ge Miao-Fu Xu Yao Gao Jin-Can Wang Hui-Hua Lu Jian-She Cao Zhi-Qiang Li Zhuo Zhang Rui Ye xiang-Zhen Zhang Shuai Li Bao-Gui Yin Mei yang Ling-Ling Gong Da-Heng Ji Lin Bian Ran Liang Ya-Jun Sun Hong Shi Institute of High Energy Physics Chinese Academy of SciencesBeijing 10049China Key Laboratory of Particle Acceleration Physics and Technology Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China University of Chinese Academy of Sciences Beijing 100049China China Spallation Neutron Source Institute of High Energy PhysicsChinese Academy of SciencesDongguan 523803China

A 16-pole superconducting multipole wiggler with a large gap of 68 mm was designed and fabricated to serve as a multipole wiggler for *** wiggler consists of 16 pairs of NbTi superconducting coils with a period length of 170 mm,and its maximum peak field is 2.6 *** magnet design,magnet poles were ***,the Lorentz force on the coils and electromagnetic force between the upper and lower halves were computed and analyzed along with the stored energy and inductance at different *** enhance the critical current of the magnet coil,all the pole coils selected for the magnet exhibited excellent performance,and appropriate prestress derived from the coil force analysis was applied to the pole coils during magnet *** entire magnet structure was immersed in 4.2-K liquid helium in the cryostat cooled solely by four two-stage cryocoolers,and the performance test of the superconducting wiggler was appropriately *** on the measured results,the first and second field integrals on the axis of the superconducting wiggler were significantly improved at different field levels after the compensation of the corrector ***,the wiggler was successfully installed in the storage ring of BEPCII operation with beams.

关键词： Superconducting multipole wiggler Force analysis Quench protection Magnetic field measurement HEPS-TF Cryostat

Unifying Fixed Time and Prescribed Time Control for Strict-Feedback Nonlinear Systems

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2025年第2期12卷 347-355页

作者： xiang chen Yujuan Wang Yongduan Song the State Key Laboratory of Power Transmission Equipment & System Security and New Technology and School of Automation Chongqing University IEEE

This paper investigates the prescribed-time tracking control problem for a class of multi-input multi-output(MIMO)nonlinear strict-feedback systems subject to non-vanishing uncertainties. The inherent unmatched and non-vanishing uncertainties make the prescribed-time control problem become much more nontrivial. The solution to address the challenges mentioned above involves incorporating a prescribed-time filter, as opposed to a finite-time filter, and formulating a prescribed-time Lyapunov stability lemma(Lemma 5). The prescribed-time Lyapunov stability lemma is based on time axis shifting time-varying yet bounded gain, which establishes a novel link between the fixed-time and prescribed-time control method. This allows the restriction condition that the time-varying gain function must satisfy as imposed in most exist prescribed-time control works to be removed. Under the proposed control method, the desire trajectory is ensured to closely track the output of the system in prescribed time. The effectiveness of the theoretical results are verified through numerical simulation.

关键词： Prescribed-time control prescribed-time filter robust control state feedback strict-feedback systems

The Security of Using Large Language Models:A Survey With Emphasis on ChatGPT

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2025年第1期12卷 1-26页

作者： Wei Zhou Xiaogang Zhu Qing-Long Han Lin Li Xiao chen Sheng Wen yang xiang the School of Science Computing and Engineering Technologies Swinburne University of Technology IEEE the School of Computer and Mathematical Sciences the University of Adelaide Adelaide the Faculty of Science and Engineering Southern Cross University the School of Information and Physical Sciences the University of Newcastle

ChatGPT is a powerful artificial intelligence(AI)language model that has demonstrated significant improvements in various natural language processing(NLP) tasks. However, like any technology, it presents potential security risks that need to be carefully evaluated and addressed. In this survey, we provide an overview of the current state of research on security of using ChatGPT, with aspects of bias, disinformation, ethics, misuse,attacks and privacy. We review and discuss the literature on these topics and highlight open research questions and future *** this survey, we aim to contribute to the academic discourse on AI security, enriching the understanding of potential risks and mitigations. We anticipate that this survey will be valuable for various stakeholders involved in AI development and usage, including AI researchers, developers, policy makers, and end-users.

关键词： Artificial intelligence (AI) ChatGPT large language models (LLMs) security

Super-high bed sintering for iron ores:variation and optimization of bed resistance

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2025年第1期32卷 40-51页

作者： Liang-ping Xu Lin Xiong Hui-bo Liu Xi-duan yang Ai-xiang Mao Pei-dun chen Guang-hui Li School of Minerals Processing and Bioengineering Central South UniversityChangsha410083HunanChina Central Research Institute Baosteel Group Co.Ltd.Shanghai201900China Manufacturing Management Department Guangdong Zhongnan Iron and Steel Co.Ltd.Shaoguan512123GuangdongChina Technology and Development Center Shandong Taishan Iron and Steel Group Co.Ltd.Jinan271100ShandongChina

As the bed depth increases,sintering yield increases,but the productivity *** reveal the reasons for the decrease in productivity and explore targeted solutions,the bed resistance of mixtures,wet zone,and combustion zone was analyzed in the *** results showed that the decreased porosity of mixture resulted in the increased bed resistance by 160.56%when the bed depth increased from 600 to 1000 *** improving porosity of 1%by adding loosening bars with optimized size and distribution,the bed resistance decreased,and the productivity increased by 5%.The increase in bed depth increased the thickness of the wet zone from 120 to 680 mm and the resistance from 1.56 to 8.83 *** using a three-stage intensive mixer and pre-adding water for granulation,the moisture of mixture was reduced by 0.6%,and the sintering productivity increased by 4%.Besides,the high bed resistance is mainly caused by the increase in the thickness of the combustion zone from 31.9 to 132.7 mm,and the bed resistance increased from 0.70 to 5.62 *** bed resistance of the combustion zone at 900 mm was increased by 90.51%compared to 700 *** optimization of the distribution of coke breeze,the thickness of combustion zone at the lower layer decreased from 132.7 to 106.84 mm and permeability improved significantly.

关键词： Super-high bed sintering Bed resistance Permeability Productivity Wet zone Combustion zone

Impacts of near-M_(s)austempering treatment on microstructure evolution and bainitic transformation kinetics of a medium Mn steel

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2025年第1期32卷 249-259页

作者： Yong-gang yang Xin-yue Liu Rui-zhi Li Yu-lai chen Hong-xiang Wu Guo-min Sun Zhen-li Mi National Engineering Research Center for Advanced Rolling and Intelligent Manufacturing University of Science and Technology BeijingBeijing 100083China Technology Center Ningbo Iron&Steel Co.Ltd.Ningbo 315800ZhejiangChina

The microstructure evolution and bainitic transformation of an Fe-0.19C-4.03Mn-1.48Si steel subjected to near-M_(s)austempering treatment were systematically investigated by combining dilatometer,X-ray diffraction,and electron *** additional austempering treatments with isothermal temperatures above M_(s)were used as *** show that the incubation period for the bainitic transformation occurs when the medium Mn steel is treated with the austempering temperature above M_(s).However,when subjected to near-M_(s)isothermal treatment,the medium Mn steel does not show an incubation period and has the fastest bainitic transformation ***,the largest volume fraction of bainite with a value of 74.7%is obtained on the condition of near-M_(s)austempering treatment after cooling to room *** and microstructure evolution analysis indicates that the elimination of the incubation period and the fastest rate of bainitic transformation are related to the preformed *** advent of preformed martensite allows the specimen to generate more bainite in a limited *** bainitic ferrite nucleation at austenite grain boundaries and through autocatalysis at ferrite/austenite interfaces,a model is established to understand the kinetics of bainite formation and it can describe the nucleation rate of bainitic transformation well when compared to the experimental results.

关键词： Medium manganese steel Bainitic transformation Microstructure Near-M_(s)austempering Transformation modeling