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Modeling of microstructure evolution of AZ80 magnesium alloy during hot working process using a unified internal state variable method

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Journal of Magnesium and Alloys 2022年第1期10卷 299-313页

作者： Zexing Su chaoyang sun Mingjia Wang Lingyun Qian Xintong Li School of Mechanical Engineering University of Science and Technology Beijing30 Xueyuan RoadHaidian DistrictBeijing 100083China Beijing Key Laboratory of Lightweight Metal Forming Beijing 100083China College of Nuclear Equipment and Nuclear Engineering Yantai UniversityYantai 264005China Shunde Graduate School of University of Science and Technology Beijing Foshan528000China

In this paper, a unified internal state variable(ISV) model for predicting microstructure evolution during hot working process of AZ80 magnesium alloy was developed. A novel aspect of the proposed model is that the interactive effects of material hardening, recovery and dynamic recrystallization(DRX) on the characteristic deformation behavior were considered by incorporating the evolution laws of viscoplastic flow, dislocation activities, DRX nucleation and boundary migration in a coupled manner. The model parameters were calibrated based on the experimental data analysis and genetic algorithm(GA) based objective optimization. The predicted flow stress, DRX fraction and average grain size match well with experimental results. The proposed model was embedded in the finite element(FE) software DEFORM-3 D via user defined subroutine to simulate the hot compression and equal channel angular extrusion(ECAE) processes. The heterogeneous microstructure distributions at different deformation zones and the dislocation density evolution with competitive deformation mechanisms were *** study can provide a theoretical solution for the hot working problems of magnesium alloy.

关键词： AZ80 magnesium alloy Internal state variable model Microstructure evolution Dynamic recrystallization Hot working process Finite element simulation

Constitutive relationship of IN690 superalloy by using uniaxial compression tests

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Rare Metals 2011年第1期30卷 81-86页

作者： sun chaoyang LIU Jinrong LI Rui ZHANG Qingdong DONG Jianxin School of Mechanical Engineering University of Science and Technology Beijing Beijing 100083China School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China

The hot deformation behavior of IN690 superalloy was characterized in a temperature range of 1273-1473 K and a strain rate range of 0.01-10 s^-1 using uniaxial compression tests on process annealed *** constitutive relations between flow stress and effective strain,effective strain rate as well as deformation temperature were *** can be concluded that the flow stress significantly reduces with the deformation temperature of IN690 superalloy ***,there is a significant increase of flow stress when the strain rate increases from 0.1 s^-1 to 10 s^-*** on the hyperbolic-sine Arrhenius-type equation,a constitutive equation considering compensation of strain was *** activation energy and the material constants（Q,n and ln A） decrease as the deformation strain *** strain dependent term is successfully incorporated in the constitutive equation through a quartic equation.A good agreement between the experimental data and the predicted results has been achieved,indicating that the proposed constitutive equation and the methods of determing the material constants are suitable to model the high temperature deformation behavior of IN690 superalloy.

关键词： superalloys compression testing constitutive equations activation energy

MoS2-intercalated carbon hetero-layers bonded on graphene as electrode materials for enhanced sodium/potassium ion storage

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Nano Research 2023年第1期16卷 473-480页

作者： Laiying Jing Junwei sun chaoyang sun Di Wu Gang Lian Deliang Cui Qilong Wang Haohai Yu State Key Lab of Crystal Materials Shandong UniversityJinan 250100China School of Materials Science and Engineering Qilu University of Technology(Shandong Academy of Sciences)Jinan 250353China Key Laboratory for Special Functional Aggregated Materials of Education Ministry School of Chemistry&Chemical EngineeringShandong UniversityJinan 250100China

MoS2 is considered as an ideal electrode material in the field of energy storage due to high theoretical specific capacity and unique layered ***,limited interlayer distance and poor intrinsic electrical conductivity restrict its potential realworld ***,an alternately intercalated structure of MoS2 monolayer and N-doped porous carbon(NC)layer is grown on reduced graphene oxide(rGO)via a chemical intercalated *** expanded interlayer distance of MoS2(0.96 nm),enlarged by the intercalation of N-doped porous carbon layers,can enhance ion diffusion mobility,provide additional reactive sites for ion storage and maintain the stability of electrode *** addition,the hierarchical structures between rGO substrate and intercalated N-doped carbon layers construct a three-dimensional(3D)conductive network,which can significantly improve the electrical conductivity and the structural *** a result,the rGO-supported MoS2/NC electrode exhibits an ultrahigh reversible capacity and remarkable long cycling stability for sodium-ion batteries(SIBs)and potassium-ion(PIBs).Meanwhile,the as-obtained MoS2/NC@rGO electrode also delivers a superior cycle performance of 250 mAh·g−1 after 160 cycles at 0.5 A·g−1 when employed as an anode for sodium-ion full cells.

关键词： MoS2 graphene expanded interlayer spacing sodium-ion batteries potassium-ion batteries

Gd_(2)O_(3) nanoparticles modified g-C_(3)N_(4) with enhanced photocatalysis activity for degradation of organic pollutants

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Journal of Rare Earths 2021年第11期39卷 1353-1361,I0002页

作者： Yipeng Zhou Fanshan Zeng chaoyang sun Jun Wu Yu Xie Fayun Zhang Senlin Rao Fahui Wang Jinbing Zhang Jinsheng Zhao Shiqian Li School of New Energy Science and Engineering Xinyu UniversityXinyu 338004China College of Environment and Chemical Engineering Nanchang Hangkong UniversityNanchang 330063China College of Chemistry and Chemical Engineering Liaocheng UniversityLiaocheng 252059China School of Materials and Environmental Engineering Fujian Polytechnic Normal UniversityFuqing 350300China

Gd_(2) O_(3) nanoparticles modified g-C_(3) N_(4) photocatalytic composites were synthesized by a simple one-step hydrothermal *** structure,morphology,optical properties of the prepared photocatalyst were characterized by X-ray diffraction(XRD),field emission scanning electron microscopy(FESEM),field emission transmission electron microscopy(FETEM) and X-ray photoelectron spectroscopy(XPS).The result demonstrates that gadolinium is mainly dispersed on the surface of g-C_(3) N_(4) in the form of Gd_(2) O_(3),and does not destroy the lattice structure of g-C_(3) N_(4).Besides,the gadolinium can cause the red shift of the absorption edge of light,narrow the band gap,and increase the separation efficiency of the photogenerated electron and hole of g-C_(3) N_(4).Especially,the specific surface area of g-C_(3) N_(4) can be significantly ***,g-C_(3) N_(4)/Gd-0.05 displays the highest photodegradation performance when it is used for degradation of methyl orange(MO),methylene blue(MB) and Rhodamine B(RhB).The photodegradation rate of g-C_(3) N_(4)/Gd-0.05 composites is 72.4% for MO,95.5% for RhB,100% for MB after120 min under visible light(λ> 420 nm) *** band gap promotes the separation of photogenerated electron and hole,which enhances the photocatalytic activity of g-C_(3) N_(4).It is noted that g-C_(3) N_(4)/Gd-0.05 exhibits excellent photocatalytic stability by the photocurrent and the cyclic photodegradation of MO.

关键词： Gd_(2)O_(3) g-C_(3)N_(4) Photocatalysis activity Visible light Hydrothermal method Rare earths

Impact of urban expansion on meteorological observation data and overestimation to regional air temperature in China

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Journal of Geographical Sciences 2011年第6期21卷 994-1006页

作者： SHAO Quanqin sun chaoyang LIU Jiyuan HE Jianfeng KUANG wenhui TAO Fulu Division of Regional Environmental Change Research Institute of Geographic Sciences and Natural Resources Research CAS Beijing 100101 China Graduate University of Chinese Academy of Sciences Beijing 100039 China National Climate Center Chinese Meteorological Administiation Beijing 100081 China

Since the implementation of the reform and opening up policy in China in the late 1970s, some meteorological stations ＇entered＇ cities passively due to urban expansion. Changes in the surface and built environment around the stations have influenced observa- tions of air temperature. When the observational data from urban stations are applied in the interpolation of national or regional scale air temperature dataset, they could lead to overes- timation of regional air temperature and inaccurate assessment of warming. In this study, the underlying surface surrounding 756 meteorological stations across China was identified based on remote sensing images over a number of time intervals to distinguish the rural sta- tions that ＇entered＇ into cities. Then, after removing the observational data from these stations which have been influenced by urban expansion, a dataset of background air temperatures was generated by interpolating the observational data from the remaining rural stations. The mean urban heat island effect intensity since 1970 was estimated by comparing the original observational records from urban stations with the background air temperature interpolated. The result shows that urban heat island effect does occur due to urban expansion, with a higher intensity in winter than in other seasons. Then the overestimation of regional air tem- perature is evaluated by comparing the two kinds of grid datasets of air temperature which are respectively interpolated by all stations＇ and rural stations＇ observational data. Spatially, the overestimation is relatively higher in eastern China than in the central part of China; however, both areas exhibit a much higher effect than is observed in western China. We concluded that in the last 40 years the mean temperature in China increased by about 1.58℃, of which about 0.01℃ was attributed to urban expansion, with a contribution of up to 0.09℃ in the core areas from the overestimation of air temperature.

关键词： urban expansion meteorological stations RS data interpolation urban heat-island intensity airtemperature

Differential immune responses in pregnant patients recovered from COYID-19

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Signal Transduction and Targeted Therapy 2021年第8期6卷 2561-2575页

作者： Ge Chen Yiming Zhang Yaoyao Zhang Jihui Ai Bin Yang Mengge Cui Qiuyue Liao Hanxiao Chen Hualin Bai Dashing Shang Jing Chen chaoyang sun Haiyi Liu Fengyuan Liu Bin Mao Guoqiang sun Lu Chen Jing-wen Lin Kezhen Li Tongji Hospital Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanHubeiChina Key Laboratory of Birth Defects and Related Diseases of Women and Children of MOE State Key Laboratory of BiotherapyWest China Second University HospitalSichuan University and Collaborative Innovation Center for BiotherapyChengduSichuanChina Biological Sciences Greenhouse College of Art&SciencesThe Ohio State UniversityColumbusOHUSA Department of Obstetrics Hubei Maternal and Child Health HospitalWuhanChina

Pregnant women are generally more susceptible to viral *** the impact of SARS-CoV-2 in pregnancy remains to be determined,evidence indicates that the risk factors for severe COVID-19 are similar in pregnancy to the general *** we systemically analyzed the clinical characteristics of pregnant and non-pregnant female COVID-19 patients who were hospitalized during the same period and found that pregnant patients developed marked lymphopenia and higher inflammation evident by higher C-reactive protein and *** elucidate the pathways that might contribute to immunopathology or protective immunity against COVID-19 during pregnancy,we applied single-cell mRNA sequencing to profile peripheral blood mononuclear cells from four pregnant and six non-pregnant female patients after recovery along with four pregnant and three non-pregnant healthy *** found normal clonal expansion of T cells in the pregnant patients,heightened activation and chemotaxis in NK,NKT,and MAIT cells,and differential interferon responses in the monocyte *** data present a unique feature in both innate and adaptive immune responses in pregnant patients recovered from COVID-19.

关键词： patients protective immunity

基于位错密度的Fe-22Mn-0.6C型TWIP钢物理本构模型研究

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金属学报 2014年第9期50卷 1115-1122页

作者：孙朝阳黄杰郭宁杨竞北京科技大学机械工程学院北京100083

基于位错密度及孪晶体积分数的演化,建立了Fe-22Mn-0.6C孪晶诱导塑性(TWIP)钢滑移和孪生的塑性物理本构模型,该模型考虑了孪晶内的滑移对整体塑性变形的贡献及孪晶区和基体区Taylor因子的差异,采用基体滑移、孪晶区孪生和滑移的加权求... 详细信息

基于位错密度及孪晶体积分数的演化,建立了Fe-22Mn-0.6C孪晶诱导塑性(TWIP)钢滑移和孪生的塑性物理本构模型,该模型考虑了孪晶内的滑移对整体塑性变形的贡献及孪晶区和基体区Taylor因子的差异,采用基体滑移、孪晶区孪生和滑移的加权求和描述微区塑性变形.考虑应变速率对热激活应力的影响,进一步建立了应变速率与屈服应力之间的关系.采用Euler法对该模型进行数值计算,将计算结果与实验结果进行对比,其平均相对误差值只有0.84%,相对于不考虑孪晶区滑移的模型和考虑孪晶区滑移但未考虑Taylor因子差异的模型,平均误差分别降低1.1%和2.9%.分析了孪晶与滑移机制的相互作用及对宏观变形的影响,结果表明,孪生速率与滑移速率之间负相关,孪生速率增大滑移速率减小;孪生趋于饱和时,孪生速率降低而滑移速率迅速增加;应变速率增加屈服应力增大,而对应变硬化率无显著影响.

关键词： TWIP钢位错密度孪晶诱导塑性本构模型应变速率

Overexpressed miR-9 promotes tumor metastasis via targeting E-cadherin in serous ovarian cancer

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Frontiers of Medicine 2017年第2期11卷 214-222页

作者： Bo Zhou Hongbin Xu Meng Xia chaoyang sun Na Li Ensong Guo Lili Guo Wanying Shan Hao Lu Yifan Wu Yuan Li Degui Yang Danhui Weng Li Meng Junbo Hu Ding Ma Gang Chen Kezhen Li Cancer Biology Research Center Tongji Hospital Tongji Medical College Huazhong University of Science and Technology Wuhan 430030 China Department of Gynecological Oncology Zhongnan Hospital of Wuhan University Hubei Key Laboratory of Tumor Biological Behaviors Hubei Cancer Clinical Study Center Wuhan 430071 China Department of Gynecology and Obstetrics the People's Hospital of Shenzhen Shenzhen 518000 China

MicroRNAs （miRNAs） play critical roles in the development and progression in various cancers. Dysfunctional miR-9 expression remains ambiguous, and no consensus on the metastatic progression of ovarian cancer has been reached. In this study, results from the bioinformatics analysis show that the 3＇-UTR of the E- cadherin mRNA was directly regulated by miR-9. Luciferase reporter assay results confirmed that miR-9 could directly target this 3＇-UTR. miR-9 and E-cadherin expression in ovarian cancer tissue was quantified by qRT- PCR. Migration and invasion were detected by wound healing and Transwell system assay in SKOV3 and A2780. qRT-PCR and Western blot were performed to detect the epithelial-mesenchymal transition-associated mRNA and proteins. Immunofluorescence technique was used to analyze the expression and subcellular localization of E- cadherin, N-cadherin, and vimentin. The results showed that miR-9 was frequently upregulated in metastatic serous ovarian cancer tissue compared with paired primary ones. Upregulation of miR-9 could downregulate the expression of E-cadherin but upregulate the expression of mesenchymal markers （N-cadherin and vimentin）. Overexpression of miR-9 could promote the cell migration and invasion in ovarian cancer, and these processes could be effectively inhibited via miR-9 inhibitor. Thus, our study demonstrates that miR-9 may promote ovarian cancer metastasis via targeting E-cadherin and a novel potential therapeutic approach to control metastasis of ovarian cancer.

关键词： ovarian cancer metastasis miR-9 E-cadherin

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不同橡胶改性沥青离析标准的试验研究

公路工程 2015年第1期40卷 221-224页

作者：孙朝阳三门峡职业技术学院河南三门峡472000

热储存过程中聚合物外加剂与基质沥青之间的相分离是沥青行业的一个重要问题。通常采用室内试验评估聚合物改性沥青相分离的程度,如铝管离析试验（CTB）。然而,不同国家对测试环境,温度和储存时间有不同的标准。基于全面的文献调差,该... 详细信息

热储存过程中聚合物外加剂与基质沥青之间的相分离是沥青行业的一个重要问题。通常采用室内试验评估聚合物改性沥青相分离的程度,如铝管离析试验（CTB）。然而,不同国家对测试环境,温度和储存时间有不同的标准。基于全面的文献调差,该文试验中,温度范围和烘箱储存时间分别选择为140~180℃和2~7 d。该研究中,对选自12个不同地方橡胶改性沥青（CRMA）的11个储存稳定条件的相分离进行了比较和评估。采用PG64—22基质沥青和不同掺量（沥青重量的10%,15%,20%）制备CRMA。选择CTB作为存储稳定性的试验方法,从铝管顶部和底部G^＊/sinδ之间的关系获得分离百分率。储存稳定性试验表明,CRMA的粘度对胶结料的相分离有显著的影响;改性沥青胶结料的粘度越高,分离的程度越低。

关键词：橡胶改性沥青(CRMA) 离析标准试验研究