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Microstructure evolution and strengthening mechanism of high -performance powder metallurgy TA15 titanium alloy by hot rolling

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International Journal of Minerals,Metallurgy and Materials 2024年第6期31卷 1426-1436页

作者： Ying Gao Ce zhang jiazhen zhang Xin Lu Beijing Advanced Innovation Center for Materials Genome Engineering State Key Laboratory for Advanced Metals and MaterialsInstitute for Advanced Ma-terials and TechnologyUniversity of Science and Technology BeijingBeijing 100083China National Engineering Research Center for Advanced Rolling Technology National Engineering Research Center for Flat Rolling EquipmentInstitute of Engin-eering TechnologyUniversity of Science and Technology BeijingBeijing 100083China

Hot deformation of sintered billets by powder metallurgy(PM)is an effective preparation technique for titanium alloys,which is more significant for high-alloying *** this study,Ti–6.5Al–2Zr–Mo–V(TA15)titanium alloy plates were prepared by cold press-ing sintering combined with high-temperature hot *** microstructure and mechanical properties under different process paramet-ers were *** microscope,electron backscatter diffraction,and others were applied to characterize the microstructure evolution and mechanical properties strengthening *** results showed that the chemical compositions were uniformly dif-fused without segregation during sintering,and the closing of the matrix craters was accelerated by increasing the sintering *** block was hot rolled at 1200℃ with an 80%reduction under only two passes without *** strength and elongation of the plate at 20–25℃ after solution and aging were 1247 MPa and 14.0%,respectively,which were increased by 24.5%and 40.0%,respect-ively,compared with the as-sintered alloy at 1300℃.The microstructure was significantly refined by continuous dynamic recrystalliza-tion,which was completed by the rotation and dislocation absorption of the substructure surrounded by low-angle grain *** hot rolling combined with heat treatment,the strength and plasticity of PM-TA15 were significantly improved,which resulted from the dense,uniform,and fine recrystallization structure and the synergistic effect of multiple slip systems.

关键词： elemental powder powder metallurgy titanium alloy hot rolling strength and plasticity

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新时代思想政治理论课建设的“质量观”演进

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北京教育（德育） 2024年第4期 37-42,53页

作者：李蕉张家臻清华大学马克思主义学院北京100084

自2019年3月习近平总书记主持召开学校思想政治理论课教师座谈会以来,教育部启动了思想政治理论课的全面改革,有关“何为高质量的思政课”的讨论也一直牵引着改革的方向。从改革“大水漫灌”到实施“精准滴灌”的“结构质量观”,从关注... 详细信息

自2019年3月习近平总书记主持召开学校思想政治理论课教师座谈会以来,教育部启动了思想政治理论课的全面改革,有关“何为高质量的思政课”的讨论也一直牵引着改革的方向。从改革“大水漫灌”到实施“精准滴灌”的“结构质量观”,从关注“抬头率”到增强“获得感”的“内容质量观”,从着眼于“立德树人”到与“人才强国战略”同频共振的“育才质量观”,思想政治理论课“质量观”的演进过程体现了时代发展对于担当民族复兴大任的时代新人和创新人才的渴求,也反映出党和国家对人才培养认识的不断深化。这三重“质量观”的更迭,是一个理论与实践互促互进的过程,而当前推进中国式现代化的各类实践,也必将进一步推动思想政治理论课在继承中发展、在守正中创新。

关键词：思想政治理论课高质量发展教育强国中国式现代化质量观

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退火处理对高压扭转ZXJ310镁合金体外降解性能的影响

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稀有金属 2024年第5期48卷 609-617页

作者：张家振马鸣龙李永军孙昭乾史文鹏郝雪龙张奎中国有研科技集团有限公司有色金属材料制备加工国家重点实验室北京101407 有研工程技术研究院有限公司北京101407 北京有色金属研究总院北京1000883 国标(北京)检验认证有限公司国家有色金属及电子材料分析测试中心北京101407

利用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、能谱仪(EDS)、腐蚀失重实验以及电化学工作站研究了退火处理对高压扭转变形(HPT)ZXJ310合金的微观组织和体外降解性能的影响。结果表明:高压扭转态ZXJ310镁合金在150℃退火时,随着退火... 详细信息

利用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、能谱仪(EDS)、腐蚀失重实验以及电化学工作站研究了退火处理对高压扭转变形(HPT)ZXJ310合金的微观组织和体外降解性能的影响。结果表明:高压扭转态ZXJ310镁合金在150℃退火时,随着退火时间延长(0~4 h),合金的平均晶粒尺寸由高压扭转态的98.3 nm,分别增长至169.8,217.6,220.2和259.5 nm。通过TEM观察可知,ZXJ310镁合金中的位错密度明显降低;电化学测试显示:随着退火时间延长,腐蚀电位明显增加,ZXJ310镁合金Nyquist图谱中的容抗弧半径逐渐增加,退火4 h后高压扭转ZXJ310镁合金的电化学腐蚀速率可以降低至0.32 mm·y^(-1);ZXJ310镁合金在模拟体液中的浸泡失重试验结果也表现出同样的趋势,3~4 h退火后的ZXJ310镁合金的耐蚀性显著提升;对ZXJ310镁合金的腐蚀产物分析可知,退火处理显著改善合金在模拟体液(SBF)溶液中的浸泡腐蚀行为,增加腐蚀产物膜层的致密性和稳定性,但不会对合金腐蚀产物的类型产生影响。不同状态下ZXJ310镁合金在相同浸泡条件下产生的腐蚀产物种类没有区别,浸泡120 h后均能产生含羟基磷灰石的Ca-P化合物。

关键词： ZXJ310镁合金高压扭转(HPT) 退火处理体外降解

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血清双酚A浓度与高血压发生风险的关联

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环境与职业医学 2024年第6期41卷 601-609页

作者：官佑兵赵卓雅程旭张佳禛刘越男何美安华中科技大学同济医学院公共卫生学院劳动卫生与环境卫生学系湖北武汉430030

[背景]现有的研究表明双酚A暴露可能与高血压风险相关,但大多数为横断面研究,且结论尚不一致。[目的]探讨双酚A暴露与高血压发生风险的关联。[方法]基于东风-同济队列的一项纳入1990名研究对象的巢式病例对照研究,在排除基线887名高血... 详细信息

[背景]现有的研究表明双酚A暴露可能与高血压风险相关,但大多数为横断面研究,且结论尚不一致。[目的]探讨双酚A暴露与高血压发生风险的关联。[方法]基于东风-同济队列的一项纳入1990名研究对象的巢式病例对照研究,在排除基线887名高血压患者和随访后血压数据缺失的23名研究对象后,共有1080名研究对象纳入本研究。通过问卷调查获得流行病学资料,采用高效液相色谱串联质谱仪检测血清双酚A质量浓度(后简称为浓度)。采用logistic回归模型分析血清双酚A水平与高血压发生风险的关联,线性回归模型分析血清双酚A水平与基线和随访血压变化值的关联。[结果]1080名研究对象的平均年龄为(62.03±7.45)岁,其中41.1%为男性。在经过随访之后,共有477人(44.2%)新发高血压。总人群中血清双酚A中位数浓度为3.15μg·L^(−1),新发病例组基线双酚A浓度(3.24μg·L^(−1))高于对照组(2.98μg·L^(−1))(P0.05)。[结论]双酚A暴露与高血压发生风险存在正向关联。

关键词：双酚A 高血压血压变化

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Effect of internal defects on tensile strength in SLM additively-manufactured aluminum alloys by simulation

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Chinese Journal of Aeronautics 2023年第10期36卷 485-497页

作者： Xin SONG Bowen FU Xin CHEN jiazhen zhang Tong LIU Chunpeng YANG Yifan YE School of Mechanical Power Engineering Harbin University of Science and TechnologyHarbin 150080China COMAC Beijing Aircraft Technology Research Institute Beijing 102211China

This research investigates the effect of internal defects on the tensile strength of Selective Laser Melting(SLM)additively-manufactured aluminum alloy(AlSi10Mg)test parts used for civil aircraft light weight design.A Finite Element Analysis(FEA)model containing internal defects was established by combining test data and the stress concentration factor comparison *** effect of variation in the number,location and shape of defects on the finite element results was *** results show that it is reasonable to use spherical defect *** finite element modeling and analysis methods are also applied to the study of the effect of internal defects on tensile strength in additive manufacturing of other metallic *** to the FEA results of single defects at different scales,the formula for calculating the weakening degree of tensile strength applicable to the defective area of less than 15%was *** result of the procedure is reliable and *** research results can guide the selection of process parameters for the additive manufacturing of aluminum ***,the research results can promote the application of metal additive manufacturing in designing light-weight civil aircraft structures.

关键词： Additive manufacturing Internal defects Tensile strength Elasticity FEA Simulation experiments

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Additive manufacturing of multi-morphology graded titanium scaffolds for bone implant applications

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Journal of Materials Science & Technology 2023年第8期139卷 47-58页

作者： Aihua Yu Ce zhang Wei Xu Yun zhang Shiwei Tian Bowen Liu jiazhen zhang Anrui He Bo Su Xin Lu Shunde Graduate School of University of Science and Technology Beijing Foshan 528399China National Engineering Research Center for Advanced Rolling and Intelligent Manufacturing Institute of Engineering TechnologyUniversity of Science and Technology BeijingBeijing 100083China Beijing Advanced Innovation Center for Materials Genome Engineering State Key Laboratory for Advanced Metals and MaterialsUniversity of Science and Technology BeijingBeijing 100083China National Engineering Technology Research Center of Flat Rolling Equipment Institute of Engineering TechnologyUniversity of Science and Technology BeijingBeijing 100083China Bristol Dental School University of BristolBristol BS12LYUK

Porous Titanium scaffolds have attracted widespread attention as bone implants for avoiding the stress shielding effect and promoting *** this study,multi-morphology graded scaffolds hy-bridized by Primitive and Gyroid structures with porosity of 50,60,and 70%were designed(denoted as PG50,PG60,and PG70,respectively)and fabricated by selective laser *** simulation results showed that the maximum von-Mises stress of hybridized scaffolds increased from 504.22 to 884.24 MPa with *** permeability and average pore size of multi-morphology PG50,PG60,and PG70 were in the range of 3.58×10^(-9)-5.50×10^(-9) m^(2) and 568.1-758.4μm,*** microstructure of multi-morphology graded scaffolds consisted of a fully martensiticα′*** permeabilities of PG50 and PG60 were 3.27×10^(-9) and 4.35×10^(-9) m^(2),respectively,which were within the range of human bone(0.01-12.1×10^(-9) m^(2)).Elastic modulus and compressive yield strength of PG50 and PG60 ranged within 5.93^(-9).86 and 180.06-257.08 MPa,***,the PG50 not only exhibited a similar elastic modulus compared to human cortical bone(10.1 GPa)but also had higher strength(257.08 vs 131 MPa).The results of in vitro biocompatibility assay showed that PG50 and PG60 have better cyto-compatibility than mono-morphology scaffolds with the same *** together,PG50 is promising to be used for the restoration of bone defects due to its excellent mechanical properties,appropriate per-meability,and good cytocompatibility.

关键词： Bone implants Multi-morphology graded titanium scaffolds Finite element analysis Selective laser melting Cytocompatibility

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Improvement and application of Y2O3 directional solidification crucible

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Chinese Journal of Aeronautics 2016年第2期29卷 554-559页

作者： Ma Limin zhang jiazhen Yue Guangquan zhang Huarui Zhou Li zhang Hu Beijing Aeronautical Science & Technology Research Institute of COMAC Bering 102211 Chinab School of Materials Science and Engineering Beihang University Beijing 100191 China

In order to satisfy the drastic temperature change and high chemical activity in direc- tional solidification of Nb Si based alloys, Y2O3 crucible is demanded to possess high thermal shock resistance and erosion resistance. This paper improved the sintering degree and density of Y2O3 crucible by optimizing the sintering temperature and time, and its practical application per- formance was investigated. Y2O3 grains gathered with the increase of sintering temperature and time, and the contact area enlarged, resulting in the open pores being changed into closed pores. The higher density caused the improvement of erosion resistance of Y2O3 crucibles. However, exces- sive density weakened the thermal shock resistance. Considering high-temperature strength, erosion resistance, thermal shock resistance and costs, optimum sintering temperature and time of Y2O3 directional solidification crucible were 1800 ℃ and 120min, respectively, and the porosity was 20%. Improved Y2O3 crucible has been successfully applied to directional solidification of Nb Si based alloys, and significantly reduced the oxygen contamination. Slight interaction occurred between Hf and Y2O3, but no obvious dissolution, penetration or erosion was found, showing good erosion resistance and thermal shock resistance.

关键词： Directional solidification Erosion resistance Microstructure Nb-Si based alloy Thermal shock resistanceY2O3 crucible

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MoS_(2)/PVDF阳离子交换膜的制备及污染物去除性能

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云南师范大学学报（自然科学版） 2024年第2期44卷 22-26页

作者：王梦琦季旭杨思霞陈盈旭张佳镇王建军云南师范大学太阳能研究所云南昆明650500

为了在提高微生物脱盐燃料电池脱盐效率的同时去除污水中的金属离子和有机染料,对传统的PVDF阳离子交换膜进行改性,通过加入MoS_(2)提高PVDF的亲水性能和吸附性能,增加了羟基等亲水基团,当加入0.5%的MoS_(2)后脱盐效率较纯的PVDF提高了6... 详细信息

为了在提高微生物脱盐燃料电池脱盐效率的同时去除污水中的金属离子和有机染料,对传统的PVDF阳离子交换膜进行改性,通过加入MoS_(2)提高PVDF的亲水性能和吸附性能,增加了羟基等亲水基团,当加入0.5%的MoS_(2)后脱盐效率较纯的PVDF提高了66.0%.有机染料亚甲基蓝(MB)去除率提高了47.1%,金属离子铅(Pb)去除率提高了37.7%.

关键词：微生物脱盐燃料电池阳离子交换膜 MoS_(2) 吸附性能脱盐性能

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Regulatory considerations for animal studies of biomaterial products

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Bioactive Materials 2022年第5期7卷 52-56页

作者： Maobo Cheng Wenbo Liu jiazhen zhang Song zhang Zhaojun Guo Lu Liu Jiaxin Tian Xiangmei zhang Jin Cheng Yinghui Liu Gang Deng Guobiao Gao Lei Sun Center for Medical Device Evaluation National Medical Products AdministrationBeijing100081China National Medical Products Administration Beijing100037China

Animal studies play a vital role in validating the concept,feasibility,safety,performance and efficacy of biomaterials products during their bench-to-clinic *** article aims to share regulatory considerations for animal studies of biomaterial *** briefly emphasizing the importance of animal studies,issues of animal studies during biomaterial products’translation are *** studies with unclear purposes,flawed design and poor reporting quality could significantly reduce the translation efficiency and create regulatory *** perspectives on the purpose,principle,quality and regulatory science of animal studies are also *** studies should have clear purposes,follow principles of 3R+DQ(replacement,reduction,refinement,design and quality)and execute under an efficiently operating quality management *** the advancement of regulatory science,National Medical Products Administration of China has been developing a series of standards and guidance documents on animal studies of medical *** studies of making decisions on whether to conduct animal studies are provided in the end with drug-eluting stents as *** summary,animal studies of biomaterial products should pay close attention to the rationale,design and quality in order to achieve their purposes.

关键词： Animal studies Biomaterials 3R(Replacement,Reduction and refinement) Design and quality

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Temporal and spatial variation and prediction of water yield and water conservation in the Bosten Lake Basin based on the PLUS-InVEST model

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Journal of Arid Land 2024年第6期16卷 852-874页

作者： CHEN jiazhen KASIMU Alimujiang REHEMAN Rukeya WEI Bohao HAN Fuqiang zhang Yan School of Geography and Tourism Xinjiang Normal UniversityUrumqi 830054China Xinjiang Key Laboratory of Lake Environment and Resources in Arid Zone Urumqi 830054China School of Geography and Tourism Shaanxi Normal UniversityXi'an 710062China

To comprehensively evaluate the alterations in water ecosystem service functions within arid watersheds,this study focused on the Bosten Lake Basin,which is situated in the arid region of Northwest *** research was based on land use/land cover(LULC),natural,socioeconomic,and accessibility data,utilizing the Patch-level Land Use Simulation(PLUS)and Integrated Valuation of Ecosystem Services and Tradeoffs(InVEST)models to dynamically assess LULC change and associated variations in water yield and water *** analyses included the evaluation of contribution indices of various land use types and the investigation of driving factors that influence water yield and water *** results showed that the change of LULC in the Bosten Lake Basin from 2000 to 2020 showed a trend of increasing in cultivated land and construction land,and decreasing in grassland,forest,and unused *** unused land of all the three predicted scenarios of 2030(S1,a natural development scenario;S2,an ecological protection scenario;and S3,a cultivated land protection scenario)showed a decreasing *** scenarios S1 and S3 showed a trend of decreasing in grassland and increasing in cultivated land;while the scenario S2 showed a trend of decreasing in cultivated land and increasing in *** water yield of the Bosten Lake Basin exhibited an initial decline followed by a slight increase from 2000 to *** areas with higher water yield values were primarily located in the northern section of the basin,which is characterized by higher *** conservation demonstrated a pattern of initial decrease followed by stabilization,with the northeastern region demonstrating higher water conservation *** the projected LULC scenarios of 2030,the estimated water yield under scenarios S1 and S3 was marginally greater than that under scenario S2;while the level of water conservation across all three scenarios remained rather *** results showed that Hejin

关键词： PLUS model InVEST model Bosten Lake Basin water yield water conservation land-use simulation Geodetector

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