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Precipitating thermally reinforcement phase in aluminum alloys for enhanced strength at 400℃

Journal of Materials Science & Technology 2024年第5期172卷 71-82页

作者： Xiang Su Yuan Lei Yang chen Hongjie Qu Zhixiang Qi Gong Zheng Xu Liu Henggao Xiang Guang chen National Key Laboratory of Advanced Casting Technologies MIIT Key Laboratory of Advanced Metallic and Intermetallic Materials TechnologyEngineering Research Center of Materials Behavior and DesignMinistry of EducationNanjing University of Science and TechnologyNanjing 210094China School of Aviation and Mechanical Engineering Changzhou Institute of TechnologyChangzhou 213032China

Heat-resistant aluminum alloys are widely used in aerospace and automotive fields for manufacturing hot components due to their advantages in lightweight design and energy ***,the high-temperature strength of existing cast aluminum alloys is always limited to about 100 MPa at 350℃due to coarsening and transformation of strengthening ***,we reveal that the yield strength and ultimate tensile strength of the T6 state Al-8.4Cu-2.3ce-1.0Mn-0.5Ni-0.2Zr alloy at 400◦C increase by 34%and 44%after re-aging at 300℃for 100 h,and its thermal strength exhibits distinguished ad-vantage over traditional heat-resistant aluminum *** enhanced elevated-temperature strength is attributed to the reprecipitation of the Ni-bearing T-Al_(20)Cu_(2)Mn_(3)phase,whose number density increases over one *** significant segregation of Ni,ce,and Zr elements at the interfaces helps improve the thermal stability of the T *** thermostable T phase effectively strengthens the matrix by in-hibiting dislocation ***,a highly interconnected 3D intermetallic network along the grain boundaries can still remain after long-term re-aging at 300℃,which is conducive to imposing a drag on the grain boundaries at high *** finding offers a viable route for enhancing the elevated-temperature strength of heat-resistant aluminum alloys,which could provide expanded opportunities for higher-temperature applications.

关键词： Aluminum alloys Precipitation Thermally reinforcement phase Re-aging treatment High-temperature strength

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Journal of Rare Earths 2024年第4期42卷 743-748页

作者： Hao Zhang Yi Bian Yuxuan Xia Yuchen Cui Ziang Li Fang Zhang Yiming Bai Nuofu chen Jikun chen School of New Energy North China Electric Power UniversityBeijing102206China School of Materials Science and Engineering University of Science and Technology BeijingBeijing100083China

While the metal to insulator transition(MIT)of d-band correlated perovskite nickelates(RENiO_(3))are widely adjustable via their rare-earth composition,the roles of potential valence variabilities associated with the rare-earth elements were rarely ***,we demonstrate the material synthesis and MIT properties of RENiO_(3) containing valence variable rare-earth compositions,such as ce,Pr,Sm,Eu and *** metastable perovskite structure of SmNiO_(3) and EuNiO_(3) with a rare-earth valence states variable towards+2 can be effectively synthesized under high oxygen pressures as it is necessary to reduce their formation free *** is in contrast to ce and Tb,in which situations the variable rare-earth valence state towards+4 reduces their ionic radius and prohibits their occupation or co-occupation of the rare-earth site within the perovskite structured RENiO_(3).Nevertheless,PrNiO_(3) with MIT properties can be effectively synthesized at lower oxygen pressures,owing to the higher stability to form a fully occupied 6s orbit associated Pr3+compared to the half-filled one related to Pr4+.The present work provides guidance for regulating the MIT properties of RENiO_(3).

关键词： Metal to insulator transition Metastable perovskites Rare-earth nickelates Oxides

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病毒性心肌炎患者外周血miR-31与Th22细胞水平的相关性分析

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中国病原生物学杂志 2022年第7期17卷 814-817,822页

作者：陈策彭建军赵博樊永燕首都医科大学附属北京世纪坛医院心内科北京100038

目的检测病毒性心肌炎(VMC)患者外周血中微小RNA-31(miR-31)、辅助型T 22(Th22)细胞及其白介素-22(IL-22)的变化,探讨miR-31与Th22细胞水平的相关性。方法从2020年1月到2021年6月期间本院收治的VMC患者中选取125例作为VMC组,根据心功能... 详细信息

目的检测病毒性心肌炎(VMC)患者外周血中微小RNA-31(miR-31)、辅助型T 22(Th22)细胞及其白介素-22(IL-22)的变化,探讨miR-31与Th22细胞水平的相关性。方法从2020年1月到2021年6月期间本院收治的VMC患者中选取125例作为VMC组,根据心功能指标(LVEF)划分为轻度组(52例)、中度组(52例)和重度组(21例),对照组为125名健康志愿者;收集外周血样本5 ml并分离单个核细胞,实时荧光定量(qRT-PCR)技术检测外周血中miR-31的表达水平,流式细胞仪检测Th22细胞水平,酶联免疫吸附实验检测IL-22表达水平,分析比较对照组与VMC组及不同病情组之间miR-31、Th22细胞及IL-22的表达水平的差异;分析VMC组外周血miR-31表达水平分别与Th22细胞水平、IL-22水平之间,及Th22细胞水平与IL-22水平之间的相关性。结果与对照组[(1.00±0.00)、(0.78±0.22)%、(21.69±3.50)pg/mL]相比,VMC组外周血中miR-31表达水平(1.45±0.32)、Th22细胞水平[(2.02±0.55)%]及IL-22[(33.34±7.44)pg/mL]水平升高(P中度组>轻度组;VMC组外周血miR-31、Th22细胞水平与IL-22表达水平均呈显著正相关(r=0.599,P<0.05;r=0.635,P<0.05);VMC组外周血miR-31表达水平与Th22细胞水平呈显著正相关(r=0.613,P<0.05)。结论VMC患者外周血的miR-31、Th22细胞及IL-22表达水平均显著升高,miR-31可能通过影响Th22介导的免疫调控在VMC的发生发展中起关键作用。

关键词：病毒性心肌炎微小RNA-31 辅助型T22细胞相关性

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轴流压气机过失速的非线性动力学分析

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航空动力学报 2007年第9期22卷 1461-1467页

作者：陈策聂超群李军中国科学院工程热物理研究所空军工程大学工程学院西安710038

为了解Greitzer的B参数和节流γ参数对轴流压气机过失速行为的影响,使用分叉分析方法,研究了压缩系统中过失速所对应的静态分叉行为.由此,划分了γ-β分叉参数空间中,轴流压缩系统稳定和不稳定流动的区域分布图.结果表明,非线性动力学... 详细信息

为了解Greitzer的B参数和节流γ参数对轴流压气机过失速行为的影响,使用分叉分析方法,研究了压缩系统中过失速所对应的静态分叉行为.由此,划分了γ-β分叉参数空间中,轴流压缩系统稳定和不稳定流动的区域分布图.结果表明,非线性动力学的分叉分析方法,可以准确的捕捉到轴流压缩系统中典型的过失速流动行为,同时可以简便的分析分叉参数作用下平衡点稳定性的变化情况.

关键词：航空、航天推进系统轴流压气机过失速非线性动力学

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多囊蛋白2离子通道功能及在常染色体显性多囊肾发病中的作用机制

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生物化学与生物物理进展 2024年第1期51卷 47-58页

作者：汪凯黄渊周策凡唐景峰陈兴珍湖北工业大学科技部/教育部细胞调控与分子药物学科“111”引智基地武汉430068 湖北工业大学发酵工程教育部重点实验室武汉430068 湖北工业大学工业发酵省部共建协同创新中心武汉430068 湖北工业大学工业微生物湖北省重点实验室武汉430068

多囊蛋白2 (polycystin-2,PC2,或称TRPP2,PKD2)是一种瞬时受体电位通道(transient receptor potential channel,TRP),在维持细胞正常的Ca~(2+)信号传导中起着关键作用,也是最常见的单基因常染色体显性遗传多囊肾病(transient receptor potential channel,ADPKD)的潜在病因之一。PC2可自身组装为同源四聚体离子通道或与其他蛋白质形成异源受体-离子通道复合物,参与调节机械感觉、细胞极性、细胞增殖和凋亡等多种生理功能,导致囊性细胞从正常的吸收、静止状态转变为病理性分泌、增殖状态。本文阐述了PC2蛋白相关结构域以及通道特性在维持细胞内Ca~(2+)信号传导中的关键作用,并总结了PC2在细胞膜、纤毛、内质网以及线粒体等特定亚细胞定位形成多囊蛋白复合物,参与多种细胞分化、增殖、存活和凋亡相关信号通路,为确定特异性的有效的ADPKD干预治疗途径和靶点药物提供新的思考方向。

关键词：多囊蛋白2 离子通道钙离子常染色体显性遗传多囊肾病

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Composite structure Al_(2)O_(3)/Al_(2)O_(3)-YAG:ce/YAG ceramics with high color spatial uniformity for white laser lighting

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Journal of Advanced ceramics 2024年第2期13卷 189-197页

作者： Pengfei Sang Le Zhang Jian Kang Mingzhou Li Shiwei chen Peng Yang Bingheng Sun Yang Li Wieslaw Strek Hao chen Jiangsu Key Laboratory of Advanced Laser Materials and Devices School of Physics and Electronics EngineeringJiangsu Normal UniversityXuzhou 221116China Jiangsu Xiyi Advanced Materials Research Institute of Industrial Technology Xuzhou 221400China Xuzhou EAGLED Technology Co. Ltd.Xuzhou 221116China Xuzhou Kangna Advanced Materials Technology Co. Ltd.Xuzhou 221116China Xuzhou Fuchang Electronic Technology Co. Ltd.Xuzhou 221116China Shanghai Institute of Optics Fine Mechanics Chinese Academy of SciencesShanghai 201800China School of Material Science and Engineering Shanghai Institute of TechnologyShanghai 201418China State Key Laboratory of Crystal Materials Shandong UniversityJinan 250100China Institute of Low Temperature and Structure Research Polish Academy of SciencesWroclaw 50-422Poland

Composite ceramic phosphor(CCP)is a candidate light-conversion material to obtain the high-quality laser lighting *** based on the transmissive configuration model could not simultaneously meet the requirements of angular color uniformity and high thermal *** this study,a novel composite structure ceramic was designed,including Al_(2)O_(3)-YAG:ce/YAG layered ceramic with a size of 1 mm×1 mm for lighting,and Al_(2)O_(3) ceramic(φ=16.0 mm)was used as the wrapping material due to its outstanding thermal *** prepared ceramics exhibited excellent thermal performance and no yellow ring *** this design,we achieved the match of the intensity distribution of the blue and yellow lights,resulting in a high angular color uniformity of 0.9 with a view angle of±80°.All ceramics showed no luminous saturation phenomenon,even the laser power density was increased up to 47.51 W/mm^(2).A high-brightness white-light source with a luminous flux of 618 lm,a luminous efficiency of 126 lm/W,a CCT of 6615 K,and a CRI of 69.9 was obtained in the transmissive *** particular,the surface temperature of the ceramic was as low as 74.1℃ under a high laser radiation(47.51 W/mm^(2)).These results indicate that Al_(2)O_(3)/Al_(2)O_(3)-YAG:ce/YAG composite structure ceramic is a promising luminescent material in the high-power laser lighting applications.

关键词： Al_(2)O_(3)/Al_(2)O_(3)-YAG:ce/YAG angular color uniformity high thermal stability high-power laser lighting

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Chain Extender-induced Hydrogen Bonding Organization Determines the Morphology and Properties of Thermoplastic Polycarbonate Polyurethane

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Chinese Journal of Polymer Science 2024年第1期42卷 87-96,I0009页

作者： Yi-Lang Qin Ping Zhu chen-Xi Ouyang Xia Dong Fuwai Hospital Chinese Academyof Medical Sciences&Peking Union Medical College/National Center for Cardiovascular DiseasesBejing 100037China CASKey Laboratoryof Engineering Plastics CAS Research/Education Centerfor Excellence in Molecular SciencesInstitute ofChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

Thermoplastic polycarbonate polyurethanes(PCUs) are multiblock copolymers that have been applied for medical devices for long time. Aliphatic diols are common chain extenders(ce) involved in the composition of the hard segments of PCU. However, limited knowledge was discovered about how the chemical structure of ce affects the hydrogen bonding organization within PCUs and their mechanical *** investigate this problem, a group of PCUs were synthesized respectively by extending the polymer chain with 1,4-butanediol(BDO),aminoethanol(MEA), ethanediol(EO) as three kinds of chain extenders. Tiny differences in the ce chemical structure results in remarkable variations in phase separation, condensed morphologies, thermal and mechanical properties, which are characterized by Fourier transform infrared spectrometer, atomic force microscopy, small-angle X-ray scattering, differential scanning calorimetry, and tensile tests. The microstructural evolution during unilateral deformation and the different mechanism induced by the different ces was probed and unveil by in situ wide-and small-angle X-ray diffraction. Symmetry of ce can improve the organization of the hydrogen bonding. The coherence strength of the urethane/urea group also plays a key role by comparing the two PCUs with ethanediol and aminoethanol.

关键词： Thermoplastic polycarbonate polyurethane Chain extender Hydrogen bonding Mechanical properties

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An Intelligent Sensor Data Preprocessing Method for OCT Fundus Image Watermarking Using an RCNN

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Computer Modeling in Engineering & Sciences 2024年第2期138卷 1549-1561页

作者： Jialun Lin Qiong chen College of Biomedical Information and Engineering Hainan Medical UniversityHaikou571199China TJ-YZ School of Network Science Haikou University of EconomicsHaikou571127China Department of Earth System Science Ministry of Education Key Laboratory for Earth SystemModelingInstitute forGlobal Change StudiesTsinghua UniversityBeijing100084China

Watermarks can provide reliable and secure copyright protection for optical coherence tomography(OCT)fundus *** effective image segmentation is helpful for promoting OCT image ***,OCT images have a large amount of low-quality data,which seriously affects the performance of ***,this paper proposes an effective segmentation method for OCT fundus image watermarking using a rough convolutional neural network(RCNN).First,the rough-set-based feature discretization module is designed to preprocess the input ***,a dual attention mechanism for feature channels and spatial regions in the CNN is added to enable the model to adaptively select important information for ***,the refinement module for enhancing the extraction power of multi-scale information is added to improve the edge accuracy in *** is compared with ce-Net and MultiResUNet on 83 gold standard 3D retinal OCT data *** average dice similarly coefficient(DSC)obtained by RCNN is 6%higher than that of *** average 95 percent Hausdorff distance(95HD)and average symmetric surface distance(ASD)obtained by RCNN are 32.4%and 33.3%lower than those of MultiResUNet,*** also evaluate the effect of feature discretization,as well as analyze the initial learning rate of RCNN and conduct ablation experiments with the four different *** experimental results indicate that our method can improve the segmentation accuracy of OCT fundus images,providing strong support for its application in medical image watermarking.

关键词： Watermarks image segmentation rough convolutional neural network attentionmechanism feature discretization

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红外激光双模复合导引头分离孔径式光学系统性能研究

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弹箭与制导学报 2023年第3期43卷 93-98页

作者：范俊李冬梅魏靖彪黄海陈策陆军航空兵研究所北京101121 中国科学院半导体研究所北京100083

红外激光双模复合制导是空面导弹未来发展的趋势之一。相比单模系统,红外激光双模复合导引头作用距离更远、抗干扰能力更强、环境适应性更好。文中分别从调制传递函数、渐晕系数、最小可分辨温差、噪声等效温差等性能指标对共孔径式和... 详细信息

红外激光双模复合制导是空面导弹未来发展的趋势之一。相比单模系统,红外激光双模复合导引头作用距离更远、抗干扰能力更强、环境适应性更好。文中分别从调制传递函数、渐晕系数、最小可分辨温差、噪声等效温差等性能指标对共孔径式和分离孔径式光学系统两种设计方案进行了仿真和对比实验,仿真和实验结果表明,相对共孔径式光学系统,分离孔径式光学系统在各项指标中均有明显的提升。分离孔径式光学系统相对于共孔径式光学系统,在33线对数条件下MTF提升了75%,无渐晕光线比例增加了25%,NETD和MRTD分别降低了61%和65%。此外,对分离孔径设计中激光光学子系统的测角线性度进行了仿真分析。结果表明,分离孔径式设计不会降低激光光学子系统的测角线性度。

关键词：双模复合导引头分离孔径式光学系统

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基于公证人机制的水产品跨链交易模型研究

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农业机械学报 2024年第6期55卷 262-271页

作者：邹一波景虎陈明葛艳王文娟上海海洋大学信息学院上海201306 农业农村部渔业信息重点实验室上海201306

随着水产品交易规模的扩大,区块链技术在产品溯源和数据共享方面得到广泛的应用,但不同企业内或同一供应链内的不同环节构建的区块链之间数据无法有效交互和共享,致使信息孤岛问题依然存在。因此提出了基于公证人机制的水产品跨链交易模... 详细信息

随着水产品交易规模的扩大,区块链技术在产品溯源和数据共享方面得到广泛的应用,但不同企业内或同一供应链内的不同环节构建的区块链之间数据无法有效交互和共享,致使信息孤岛问题依然存在。因此提出了基于公证人机制的水产品跨链交易模型,旨在实现水产品不同环节之间的跨链交易,解决单点故障问题,并提升交易效率。同时针对水产品跨链交易业务特点,提出两阶段跨链交易流程,完善交易错误处理机制,从而解决跨链交易过程中的数据一致性、原子性需求,并基于Hyperledger Fabric平台构建系统原型。实验结果表明,在交易量较大的情况下,交易平均成功率高于99%,平均延迟时间为0.21s左右,模型在保证交易安全性的前提下,满足了水产品区块链跨链交易需求。

关键词：公证人机制水产品跨链交易模型区块链

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