| 1 | Microstructure and Size‑Dependent Mechanical Properties of Additively Manufactured 316L Stainless Steels Produced by Laser Metal Deposition显示文摘Metal additive manufacturing(AM),as a disruptive technology in the feld of fabricating metallic parts,has shown its ability to design component with macrostructural complexity.However,some of these functionally complex structures typically contain a wide range of feature sizes,namely,the characteristic length of elements in AM-produced components can vary from millimeter to meter-scale.The requisite for controlling performance covers nearly six orders of magnitude,from the microstructure to macro scale structure.Understanding the mechanical variation with the feature size is of critical importance for topology optimization engineers to make required design decisions.In this work,laser metal deposition(LMD)is adopted to manufacture 316L stainless steel(SS)samples.To evaluate the efect of defects and specimen size on mechanical properties of LMD-produced samples,fve rectangular sample sizes which ranged from non-standard miniature size to ASTM standard sub-sized samples were machined from the block.Tensile test reveals that the mechanical properties including yield strength(YS),ultimate tensile strength(UTS),and elongation to failure(εf)are almost the identical for samples with ASTM standard size.Whilst,relatively lower YS and UTS values,except forεf,are observed for samples with a miniature size compared with that of ASTM standard samples.Theεf values of LMD-produced 316L SS samples show a more complex trend with sample size,and are afected by three key infuencing factors,namely,slimness ratio,cluster of pores,and occupancy location of lack of fusion defects.In general,theεf values exhibit a decreasing trend with the increase of slimness ratio.Microstructure characterization reveals that the LMD-produced 316L samples exhibited a high stress status at low angle grain boundaries,whilst its location changed to high angle grain boundaries after plastic deformation.The grain size refnement and austenite-to-martensite phase transformation occurred during plastic deformation might be responsible for the very high YS and UTS attained in this study.The experimental works carried out in this study is expected to provide a guideline for evaluating the mechanical properties of LMD-produced parts with complex structure,where critical parameter such as a certain slimness ratio has to be considered. | Hua‑Zhen Jiang Qi‑Sheng Chen Zheng‑Yang Li Xin‑Ye Chen Hui‑Lei Sun Shao‑Ke Yao Jia‑Huiyu Fang Qi‑Yun Hu | 2023 | Acta Metallurgica Sinica(English Letters)2023，36，1： | 0 |
| 2 | Best practice for infection prevention in pediatric respiratory clinics during the COVID‑19 epidemic显示文摘During the COVID-19 epidemic,it is important for ensuring infection prevention and control in the pediatric respiratory clinics.Herein,we introduced the practice of infection prevention and control in pediatric respiratory clinics in China.Triage measures for patients who visit respiratory clinics,quality control for pediatric respiratory clinics and other preventive measures for related examinations and treatment have been introduced in this review article. | Jing Zhang Lei Zhang Yong Yin Quan Lu Jian‑Guo Hong Xiao‑Bo Zhang Xiao‑Jian Zhou Li‑Bo Wang Jian‑Hua Zhang Min Lu Xiao‑Yan Dong Jie Shao Yan‑Ming Lu Jun Yu Li Gu Respiratory Disease Group,Pediatric Committee of Shanghai Medical Association,Shanghai,China | 2020 | World Journal of Pediatrics2020，16，4： | 0 |
| 3 | The MING proposal at SHINE:megahertz cavity enhanced X‑ray generation显示文摘The cavity-based X-ray free-electron laser(XFEL)has promise in producing fully coherent pulses with a bandwidth of a few meV and very stable intensity,whereas the currently existing self-amplified spontaneous emission(SASE)XFEL is capable of generating ultra-short pulses with chaotic spectra.In general,a cavity-based XFEL can provide a spectral brightness three orders of magnitude higher than that of the SASE mode,thereby opening a new door for cutting-edge scientific research.With the development of superconducting MHz repetition-rate XFEL facilities such as FLASH,European-XFEL,LCLS-II,and SHINE,practical cavity-based XFEL operations are becoming increasingly achievable.In this study,megahertz cavity enhanced X-ray generation(MING)is proposed based on China’s first hard XFEL facility-SHINE,which we refer to as MING@SHINE. | Nan‑Shun Huang Zi‑Peng Liu Bang‑Jie Deng Zi‑Han Zhu Shao‑Hua Li Tao Liu Zheng Qi Jia‑Wei Yan Wei Zhang Sheng‑Wang Xiang Yang‑Yang Lei Ya Zhu Yong‑Zhou He Qi‑Bing Yuan Fei Gao Rong‑Bing Deng Sen Sun Zhi‑Di Lei Zhi‑Qiang Jiang Meng‑Qi Duan Yuan Zhuan Xue‑Fang Huang Peng‑Cheng Dong Zhong‑Liang Li Shang‑Yu Si Lian Xue Si Chen Yong‑Fang Liu Ya‑Jun Tong Hai‑Xiao Deng Zhen‑Tang Zhao | 2023 | Nuclear Science and Techniques2023，34，1： | 2 |
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