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Design of a low-alloy high-strength and high-toughness martensitic steel

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International Journal of Minerals,Metallurgy and Materials 2013年第8期20卷 733-740页

作者： Yan-jun Zhao Xue-ping Ren wen-chao yang Yue Zang School of Materials Science and Engineering Guangxi University School of Materials Science and Engineering University of Science and Technology Beijing

To develop a high strength low alloy （HSLA） steel with high strength and high toughness, a series of martensitic steels were studied through alloying with various elements and thermodynamic simulation. The microstructure and mechanical properties of the designed steel were investigated by optical microscopy, scanning electron microscopy, tensile testing and Charpy impact test. The results show that cementite exists between 500℃ and 700℃, M7C3 exits below 720℃, and they are much lower than the austenitizing temperature of the designed steel. Furthermore, the Ti（C,N） precipitate exists until 1280℃, which refines the microstructure and increases the strength and toughness. The optimal alloying components are 0.19% C, 1.19% Si, 2.83% Mn, 1.24% Ni, and 0.049% Ti; the tensile strength and the V notch impact toughness of the designed steel are more than 1500 MPa and 100 J, respectively.

关键词： high strength steel martensitic steel alloy design thermodynamics alloying elements microstructuremechanical properties

Geant4 analysis and optimization of a double crystal phoswich detector for beta–gamma coincidence detection

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Nuclear Science and Techniques 2018年第4期29卷 92-97页

作者： Xing Fan Xian-Peng Zhang Geng Tian chao-wen yang Department of Nuclear Engineering and Technology College of Physics Science and Technology Sichuan UniversityChengdu 610064 China Key Laboratory of Radiation Physics and Technology Ministry of Education Sichuan University Chengdu 610064China Northwest Institute of Nuclear Technology Xi’an 710024China

In this study, a novel phoswich detector for beta–gamma coincidence detection is designed. Unlike the triple crystal phoswich detector designed by researchers at the University of Missouri, Columbia, this phoswich detector is of the semi-well type, so it has a higher detection efficiency. The detector consists of BC-400 and NaI:Tl with decay time constants of 2.4 and 230 ns, *** BC-400 scintillator detects beta particles, and the Na I:Tl cell is used for gamma detection. Geant4 simulations of this phoswich detector find that a 2-mm-thick BC-400 scintillator can absorb nearly all of the beta particles whose energies are below 700 keV. Further, for a 2.00-cmthick NaI:Tl crystal, the gamma source peak efficiency for photons ranges from a maximum of nearly 90% at 30 keV to 10% at 1 MeV. The self-absorption effect is also discussed in this paper in order to determine the carrier gas' s influence.

关键词： Geant4 Phoswich detector Beta–gamma coincidence detection Detection efficiency

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预测典型变形高温合金均匀化动力学的新模型

Transactions of Nonferrous Metals Society of China 2024年第4期34卷 1178-1190页

作者：张献光杨文超周扬闫建昊肖东平税烺付建辉孙飞石鹏陈佳俊裴逸武张健北京科技大学绿色低碳钢铁冶金全国重点实验室北京100083 北京科技大学冶金与生态工程学院北京100083 成都先进金属材料产业技术研究院股份有限公司成都610300 攀钢集团研究院有限公司攀枝花617000 Department of Material Design Innovation Engineering Nagoya UniversityFuro-choChikusa-kuNagoya 464-8603Japan

提出一种基于扩散距离概念的变形高温合金均匀化动力学新预测模型。通过定量电子探针(EPMA)分析,系统研究典型镍基变形高温合金(GH4141)的微观偏析和均匀化动力学。研究发现,基于残余偏析指数模型预测的均匀化动力学与实际测量结果之间... 详细信息

提出一种基于扩散距离概念的变形高温合金均匀化动力学新预测模型。通过定量电子探针(EPMA)分析,系统研究典型镍基变形高温合金(GH4141)的微观偏析和均匀化动力学。研究发现,基于残余偏析指数模型预测的均匀化动力学与实际测量结果之间存在一定差异。实验和理论分析均表明,考虑了过去通常被忽略的扩散方向因子的一维扩散距离模型可以合理地预测均化动力学。新模型在只需知道原始枝晶臂间距和扩散系数前提下即可完成预测计算,这为变形高温合金均匀化动力学预测提供了一种新的选择。

关键词：变形高温合金微观偏析均匀化动力学预测模型扩散距离

Microstructural Characteristics and Mechanical Behavior of Spark Plasma-Sintered Cu–Cr–rGO Copper Matrix Composites

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Acta Metallurgica Sinica(English Letters) 2018年第7期31卷 761-770页

作者： Xin-Jiang Zhang Zhong-Kui Dai Xue-Ran Liu wen-chao yang Meng He Zi-Run yang School of Materials Science and Engineering Yancheng Institute of Technology College of Materials Science and Engineering Guangxi University

Copper matrix composites were prepared through spark plasma sintering （SPS） process, mixing fixed amount of reduced graphene oxide （rGO） with the different amounts of Cr. In the sintered bulk composites, the layered rGO network and uniform Cr particles distributed in the Cu matrix. Both of mechanical blending and freeze-drying stages of the wet-mixing process obtained the Cu/Cr/rGO mixture powders, and then SPS solid-phase sintering realized the faster densification of these mixture powders. The hardness and compressive yield strength of the Cu-Cr-rGO composites depicted the higher values than those of pure Cu and single rGO-added composite, and they were gradually increased with increasing Cr. The rGO/Cr hybrid second-phases are believed to be beneficial to strengthening Cu matrix. The relevant formation and strengthening mechanisms involved in Cu-Cr-rGO composites were discussed.

关键词： Metal matrix composites(MMC) Powder metallurgy Sintering Mechanical properties

Role of radiative and convective heat transfer during heating of an ingot product in a tubular furnace:experiment and simulation

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Journal of Iron and Steel Research International 2022年第12期29卷 1978-1985页

作者： wen-chao yang yang Zhou Jian Zhang Huan Liu Ying-jie Ren Jia-jun Chen Xian-guang Zhang School of Metallurgical and Ecological Engineering University of Science and Technology Beijing(USTB)Beijing 100083China Chengdu Advanced Metal Materials Industrial Technolgy Research Institute Co. Ltd.Chengdu 610300SichuanChina

Convective heat transfer and radiative heat transfer are two essential heat transfer modes in the heating process of steel;it is important to understand the role of them during the heating process *** effects of the convective and radiative heat transfer during the heating process of a cast ingot in a tubular furnace have been studied by the designed natural and forced convection experiments and mathematical *** heating time for the center of the ingot to reach the furnace temperature is decreased with the increase in furnace *** to the experimental and simulation results,a model is proposed regarding the role of radiative and convective heat transfer in the heating *** low temperature,the convective heat transfer plays a dominant role,while at high temperature,the influence of radiative heat transfer is *** a critical temperature exists between *** forced convective heat transfer can enhance the influence of the convective heat *** critical temperature can be shifted to higher temperatures.

关键词： Reheating Tubular furnace Cast ingot Convective heat transfer Radiative heat transfer

4D label-free proteomic analysis of vitreous from patients with rhegmatogenous retinal detachment

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International Journal of Ophthalmology(English edition) 2023年第4期16卷 523-531页

作者： Qiu-Yi Huo Meng-chao Zhu wen-chao yang Yi-Peng Wang Song Chen wenzhou Medical University Wenzhou 325027Zhejiang ProvinceChina Anyang Eye Hospital Anyang 455000Henan ProvinceChina Tianjin Eye Hospital Tianjin Eye InstituteTianjin Key Lab of Ophthalmology and Visual ScienceNankai University Affiliated Eye HospitalTianjin 300020China

AIM:To identify metabolites,proteins,and related pathways involved in the etiology of rhegmatogenous retinal detachment(RRD)for use as biomarkers in diagnosing and treating ***:Vitreous specimens were collected and liquid chromatography-tandem mass spectrometry analysis was per formed using the four-dimensional label-free *** significant differentially expressed proteins,gene ontology(GO)terms,Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway representations,and protein interactions were ***:Nine specimens were subjected to proteomic *** total,161 proteins were identified as differentially expressed proteins(DEPs),including 53 upregulated proteins and 108 downregulated *** functional analysis revealed that some DEPs were enriched in neuron-related terms and membrane protein ***,KEGG analysis indicated that the cell adhesion molecule metabolic pathway was associated with the greatest number of ***,the evaluation of protein-protein interaction network revealed that DEPs were clustered in neuronal adhesion,apoptosis,inflammation and immune responses,correct protein folding,and ***:Proteomic profiling is useful for the exploration of molecular mechanisms that underlie *** study reveals increased expression levels of proteins related to heat shock protein content,glycolysis,and inflammatory responses in *** regarding biomarkers of RRD pathogenesis may help to prevent the occurrence of RRD in the future.

关键词： vitreous rhegmatogenous retinal detachment proteome 4D label-free

Aerodynamic characteristics of a pitching airfoil with leading-edge morphing

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Chinese Journal of Aeronautics 2024年第7期37卷 81-92页

作者： chaoyuan wen Yuting DAI Yuntao XU chao yang School of Aeronautic Science and Engineering Beihang UniversityBeijing 100191China Tianmushan Laboratory Hangzhou 311115China

This paper focuses on the effect of the phase offset of Leading-Edge(LE)morphing on the aerodynamic characteristics of a pitching NACA0012 *** an unstretched camber and using polynomial interpolation,an explicit expression for LE nonlinear morphing is proposed and implemented for the large pitching motion of the *** field results and aerodynamic forces are obtained by solving the unsteady Reynolds-averaged Navier-Stokes equations for both the airfoil’s pitching motion and LE ***,the index of instantaneous aerodynamic power is used to quantify the work done by the airflow in a dynamic *** to the instantaneous aerodynamic power and energy map,which denotes the energy transfer between the airfoil’s oscillation and flow field,the airfoil is subject to stall *** results show that LE morphing with an optimal phase offset of 315°reduces the energy extraction from the flow field,suppressing the stall flutter *** optimal phase offset is effective at different pitching axis positions of the *** results signify that LE morphing can suppress stall flutter by advancing the occurrence of the first LE vortex and increasing the nose-down moment during the upstroke period.

关键词： Aerodynamics Computational fluid dynamics Leading-edge morphing OpenFOAM Dynamic stall Dynamic mesh

Photochemical and electrochemical strategies in C-F bond activation and functionalization

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Organic Chemistry Frontiers 2022年第3期9卷 853-873页

作者： Zhanghong Wang Yu Sun Liu-Yu Shen wen-chao yang Fei Meng Pinhua Li College of Eco-Environmental Engineering Guizhou Minzu UniversityGuiyang 550025PR China School of Horticulture and Plant Protection Yangzhou UniversityYangzhou 225009P.R.China Anhui Laboratory of Clean Catalytic Engineering Anhui Laboratory of Functional Complexes for Materials Chemistry and ApplicationCollege of Chemical and Environmental EngineeringAnhui Polytechnic UniversityWuhuAnhui 241000P.R.of China

The activation and functionalization of C-F bonds under mild conditions can serve as an important tool for organic syntheses including the modification of pharmaceuticals and agrochemicals and the synthesis of value-a... 详细信息

关键词： bonds activation functionalization

Chronic photodamage in the chicken retina using 650-nm semiconductor laser

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International Journal of Ophthalmology(English edition) 2019年第6期12卷 936-942页

作者： Yi-Peng Wang Ze-Yu Liang Song Chen wen-chao yang Jia-Hui Kong Clinical College of Ophthalmology Tianjin Medical UniversityTianjin 300000China Anyang Eye Hospital Anyang 455000Henan ProvinceChina Tianjin Key Laboratory of Ophthalmology and Visual Science Tianjin Eye HospitalTianjin 300000China

AIM: To investigate the occurrence of chronic photodamage in the cone-based retina, following long-term exposure to a 650-nm semiconductor laser(power: 2 mW). METHODS: Chickens fed for 1 mo under natural light after hatching were irradiated with 650-nm laser light at different times each day. Fifteen animals were included in each group. Group A was a control group, irradiated with natural light during the entire study. Group B was irradiated with laser for 3 min/d. Group C was irradiated with laser for 6 min/d. Group D was irradiated with laser for 30 min/d. The duration of the light experiment was 6 mo. We obtained data at 1, 3, and 6 mo, including measuring the retinal thickness in vivo using optical coherence tomography, hematoxylin and eosin staining, TUNEL assay, apoptosis staining, malondialdehyde(MDA) content, superoxide dismutase(SOD) activity, and Western blotting to detect changes in L/M opsins and rhodopsin. RESULTS: At 1 mo, the MDA content in Group D was higher than that observed in Group A(P=0.019). At 3 mo the MDA content in Groups C and D was higher than that reported in Group A(P=0.026, 0.003). At 6 mo, the MDA content in Groups B, C, and D was higher than that observed in Group A(P=0.038, 0.032, 0.000, respectively). There was no difference in SOD activity, and L/M opsin and rhodopsin content between the groups at 1 and 3 mo. The SOD activity in group D was significantly decreased at 6 mo(P=0.000), as was the content of rhodopsin. There was no significant reduction observed in retinal thickness, abnormal cell arrangement, and positive staining of TUNEL in the groups during the 6-month study ***: Irradiation using a 650 nm semiconductor laser(power: 2 mW) for 6 min per day over 6 mo do not cause photodamage. Similarly, a 3-month exposure of 30 min per day do not cause damage. However, irradiation for 6 mo resulted in a significant increase in the content of free radicals and a decrease in the content of rhodopsin in the retina, suggest

关键词： light/adverse effects oxidative stress red light apoptosis chicken retina