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Fabrication of Si_(3)N_(4)/Cu direct-bonded heterogeneous interface assisted by laser irradiation

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Journal of Materials Science & Technology 2022年第4期99卷 169-177页

作者： yanyu song Duo Liu Guobiao Jin Haitao Zhu Naibin Chen Shengpeng Hu Xiaoguo song Jian Cao State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China Shandong Provincial Key Lab of Special Welding Technology Harbin Institute of Technology at WeihaiWeihai 264209China

Joining of ceramic and metal is a key component in microelectronic device manufacturing,in which the integrity of bonded interface is critical in the performance and stability of the devices.Current methods with a problem of thick transition layer at the interface impeded heat flow,which degraded device service life seriously.Herein,we propose a laser-assisted bonding approach to join ceramic to metal directly without any intermediate material.By focusing the laser on the surface of β-Si_(3)N_(4) ceramic,the Si microcrystalline layer with stacked α-Si_(3)N_(4) nanocrystals was prepared first.The face-centered cubic(fcc)Si and hexagonal close-packed(hcp)β-Si_(3)N_(4) substrate take the coherent orientation relations of[001]_(fcc)║[0001]_(hcp) and(220)_(fcc)║(10■0)_(hcp).Then,the defect-free Si_(3)N_(4)/Cu bonded interface obtained by the reaction of the formed Si and Cu at elevated temperature in the 805-900℃range for 30 min demonstrated a strong and stable joining of ceramic to metal.The introduction of the laser provides a novel approach to join ceramics to metals,and the ceramic/metal component is expected to be a new configuration for package substrate in high-power device applications.

关键词： Laser-assisted direct bonding Silicon nitride Laser irradiation Thermal decomposition Ceramic/metal heterointerfaces

Ceftriaxone sodium degradation by carbon quantum dots(CQDs)-decorated C-doped a-Bi_(2)O_(3) nanorods

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Environmental Science and Ecotechnology 2023年第1期13卷 96-106页

作者： Xianbo Sun Ying Pan yanyu song Wen Liu Long D.Nghiem Qilin Wang Zhengqing Cai National Engineering Research Center of Industrial Wastewater Detoxication and Resource Recovery East China University of Science and TechnologyShanghai200237China The Key Laboratory of Water and Sediment Sciences Ministry of EducationCollege of Environmental Sciences and EngineeringPeking UniversityBeijing100871China Centre for Technology in Water and Wastewater School of Civil and Environmental EngineeringUniversity of Technology SydneyUltimoNSW2007Australia Shanghai Institute of Pollution Control and Ecological Security Shanghai200237China

A novel carbon quantum dots decorated C-doped a-Bi_(2)O_(3)photocatalyst(CBO/CQDs)was synthesized by solvothermal method.The synergistic effect of adsorption and photocatalysis highly improved contaminants removal efficiencies.The ceftriaxone sodium degradation rate constant(k)of CBO/CQDs was 11.4 and 3.2 times that of pure a-Bi2O3 and C-doped a-Bi_(2)O_(3),respectively.The interstitial carbon doping generated localized states above the valence band,which enhanced the utilization of visible light and facilitated the separation of photogenerated electrons and holes;the loading of CQDs improved the charge carrier separation and extended the visible light response;the reduced particle size of CBO/CQDs accelerated the migration of photogenerated carriers.The·O2-and ht were identified as the dominant reactive species in ceftriaxone sodium degradation,and the key role of·O2-was further investigated by NBT transformation experiments.The Fukui index was applied to ascertain the molecular bonds of ceftriaxone sodium susceptible to radical attack,and intermediates analysis was conducted to explore the possible degradation pathways.The toxicity evaluation revealed that some degradation intermediates possessed high toxicity,thus the contaminants require sufficient mineralization to ensure safe discharge.The present study makes new insights into synchronous carbon dopping and CQDs decoration on modification of a-Bi2O3,which provides references for future studies.

关键词： Photocatalytic Antibiotics C-doped Carbon quantum dots Toxicity assessment

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扩散光学成像方法及应用(特邀)

激光与光电子学进展 2024年第8期61卷 1-26页

作者：宋博文赵雁雨北京航空航天大学医学科学与工程学院北京100191

扩散光学成像技术在生物医学领域有着广泛的应用。相较于磁共振成像(MRI)、计算机X射线断层扫描(CT)、正电子发射断层扫描(PET)和超声成像等成像方式,扩散光学成像利用经组织吸收和散射的扩散光进行成像,可无创、无标记、宽场、定量测... 详细信息

扩散光学成像技术在生物医学领域有着广泛的应用。相较于磁共振成像(MRI)、计算机X射线断层扫描(CT)、正电子发射断层扫描(PET)和超声成像等成像方式,扩散光学成像利用经组织吸收和散射的扩散光进行成像,可无创、无标记、宽场、定量测量氧合血红蛋白、脱氧血红蛋白、血氧、水分、脂质、黑色素等成分浓度和组织功能信息,在安全性、特异性和系统成本等方面有明显优势。本文介绍了扩散光学成像的基本原理,包括光与组织的相互作用和光传播模型,并总结扩散光学成像的相关方法和应用,包括脉搏血氧术、漫射光谱、扩散光学层析成像、荧光分子层析成像和空间频域成像,并对它们的未来发展进行了展望。

关键词：扩散光学成像组织光学功能信息生物医学光学

Joining of SiO2 ceramic and TC4 alloy by nanoparticles modified brazing filler metal

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Chinese Journal of Aeronautics 2020年第1期33卷 383-390页

作者： Hong BIAN yanyu song Duo LIU Yuzhen LEI Xiaoguo song Jian CAO State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China Shandong Provincial Key Lab of Special Welding Technology Harbin Institute of Technology at WeihaiWeihai 264209China

Nano-Al2O3 particles modified Ag Cu Ni filler was adopted to braze the SiO2 ceramic and TC4.The effects of filler size as well as the brazing temperature on the interfacial microstructure and mechanical property of the joints were investigated.Nanoscale filler reduced the phases dimension and promoted the homogeneous distribution of microstructure,obtaining a higher joint strength when compared to microscale filler.The increase of brazing temperature made the accelerating dissolution and diffusion of Ti,which promoted the increase of thickness of Ti4O7+TiSi2 layer adjacent to SiO2 ceramic and diffusion layer zone nearby TC4 alloy.The hypoeutectic structure was produced in the brazing seam due to the high Ti content.The maximum shear strength of^40 MPa was obtained at 950°C for 10 min.

关键词： Brazing Microstructure Nanoparticles modified filler SiO2 ceramic TC4

Brazing of C/C composite and Ti-6Al-4V with graphene strengthened AgCuTi filler:Effects of graphene on wettability,microstructure and mechanical properties

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Chinese Journal of Aeronautics 2018年第7期31卷 1602-1608页

作者： Duo LIU yanyu song Yinghao ZHOU Xiaoguo song Wei FU Jicai FENG State Key Laboratory of Advanced Welding and Joining Harbin Institute of Technology Shandong Provincial Key Laboratory of Special Welding Technology Harbin Institute of Technology at Weihai

Graphene nanosheets（GNSs） strengthened AgCuTi composite filler（AgCuTiG） was used to braze C/C composite and Ti-6Al-4V. The effects of GNSs on the wettability of AgCuTiG filler on the C/C composite surface and the interfacial microstructure and mechanical properties of brazed joints were investigated. The results indicate that the addition of GNSs reduced the wettability of AgCuTiG. The interfacial microstructure of brazed joints evolved with the addition of GNSs, where Ti3Cu4 and TiCu4 were converted to TiCu and the thickness of the reaction layer adjacent to the base material decreased. The maximum shear strength of joints brazed at 0.3 wt% GNSs was 23.3 MPa（880℃/10 min）. Further adding GNSs deteriorated the shear strength of the joints. Fracture of the joints occurred in the C/C composite substrate and the TiC layer adjacent to C/C composite.

关键词： Brazing Graphene nanosheets Mechanical properties Microstructure Wetting

Wetting behavior of AgCu-4.5Ti filler reinforced by carbon nanotubes on C/C composite

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Chinese Journal of Aeronautics 2021年第12期34卷 205-213页

作者： Xingyi LI Ling LIU yanyu song Duo LIU Shengpeng HU Xiaoguo song Jian CAO State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China Shandong Prorincial Key Laboratory of Special Welding Technology Harbin Institute of Technology at WeihaiWeihai 264209China Hun cm Marketing Company PetroChina Company LimitedChangsha 410005China

The effect of Carbon Nanotubes(CNTs)content on the wettability of AgCu-4.5Ti+x CNTs(wt%)composite filler alloys on C/C composite was investigated.The results show that the added CNTs reacted with element Ti in the filler and produced the dispersed fine in situ synthesized TiC particles,which increased the consumption of element Ti and provided the nucleus for the growth of Ti-Cu compounds simultaneously.The above effects of introducing CNTs,inhibited the formation of Ti-Cu compounds,also changed the distribution of compounds,which dramatically influenced the interfacial microstructure and characteristics of wetting behavior.The increase of CNTs content refined and dispersed coarse Ti-Cu compounds,decreased the initial spreading temperature,and improved the wettability,but high content of CNTs(more than 0.3 wt%)decreased the wettability of the filler alloy.The wetting interfacial microstructure of corresponding composite filler alloys were analyzed by Scanning Electron Microscope(SEM),Energy Dispersive X-ray Spectrometer(EDS)and Transmission Electron Microscope(TEM),which consisted of TiC,TiCu,TiCu;and TiCu;compound.The typical wetting behavior of AgCu-4.5Ti+0.3wt%CNTs composite filler on C/C composite was divided into four stages.The effect mechanism of CNTs content on the wetting behavior was proposed.

关键词： C/C composite Carbon Nanotubes(CNTs) Composite filler Microstructure Wetting

Vacuum brazing of GH99 superalloy using graphene reinforced BNi-2 composite filler

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Journal of Materials Science & Technology 2018年第10期34卷 1843-1850页

作者： Duo Liu yanyu song Bin Shi Qi Zhang Xiaoguo song Hongwei Niu Jicai Feng State Key Laboratory of Advanced Welding and Joining Harbin Institute of Technology Shandong Provincial Key Laboratory of Special Welding Technology Harbin Institute of Technology at Weihai

A novel graphene reinforced BNi-2 composite filler was developed for brazing GH99 superalloy. The interracial microstructure of brazed joints was analyzed by field emission scanning electron microscope and a transmission electron microscope. The effects of graphene addition on the microstructure evolu-tion and mechanical properties of brazed joints were investigated, and the strengthening mechanism of graphene was analyzed. The results revealed that due to the addition of graphene, M23（C,B）6 compounds were synthesized in the y solid solution and brittle boride precipitates near the brazing seam decreased. Graphene was effective in retarding solute atoms diffusion thus impeding the precipitation of borides. Furthermore, the low coefficient of thermal expansion （CTE） of graphene was conducive to relieve stress concentration of the brazed joints during the cooling process. The shear strengths of brazed joints were significantly improved by exerting the strengthening effect of graphene. The maximum shear strengths of the brazed joints were 410.4 MPa and 329.7 MPa at room temperature and 800 ℃, respectively.

关键词： Graphene GH99 superalloy Brazing Microstructure Mechanical properties

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高判别精度的区块链交易合法性检测方法

计算机工程与应用 2024年第5期60卷 271-280页

作者：蔡元海宋甫元黎凯陈彦宇付章杰南京信息工程大学数字取证教育部工程研究中心南京210044 西安电子科技大学综合业务网理论及关键技术国家重点实验室西安710071

区块链上的交易合法性检测对于加密数字货币的监管具有重大意义。针对现有交易合法性检测方法存在的检测精度低下、判别过程中难以有效兼顾交易本身信息与前后拓扑信息的问题,提出融合可信深度森林的多角度高精度合法性检测方法。设计... 详细信息

区块链上的交易合法性检测对于加密数字货币的监管具有重大意义。针对现有交易合法性检测方法存在的检测精度低下、判别过程中难以有效兼顾交易本身信息与前后拓扑信息的问题,提出融合可信深度森林的多角度高精度合法性检测方法。设计基于可信生成特征的可信深度森林TForest,以特征重排序的方式赋予子样本足够的区分度,结合可变滑动窗口以均衡无混淆的方式提取可信子样本,在大幅度降低生成特征维度的基础上,提高了深度森林的判别精度。提出一种集成策略,基于不同基模型对于正负样本识别能力的差异性,采用双阶段逐层优化的方式有效融合可信深度森林与Transformer图网络及残差网络三类基判别器,兼顾两方面信息,构成高精度的多角度分析模型T2Rnet。在Elliptic数据集上的实验结果显示,该模型的F1-score达到83.11%,相比基准图卷积方法提升31.6%,具备可靠的交易合法性检测性能。

关键词：区块链合法性检测可信深度森林神经网络双阶段集成

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生物多样性 2024年第5期32卷 56-67页

作者：艾妍雨胡海霞沈婷莫雨轩杞金华宋亮中国科学院西双版纳热带植物园热带森林生态学重点实验室云南勐腊666303 中国科学院大学北京100049 中国科学院昆明植物研究所山地未来研究中心昆明650201 中国科学院昆明植物研究所红河山地未来研究中心云南红河654400 云南哀牢山森林生态系统国家野外科学观测研究站云南景东676200

附生维管植物对维持森林生态系统的生物多样性、碳储量、生态水文和养分通量有重要贡献。评估附生植物的多样性格局可以为其群落构建机制以及全球变化背景下附生植物的保护和资源利用提供依据。本文以哀牢山中山湿性常绿阔叶林1.44ha塔... 详细信息

附生维管植物对维持森林生态系统的生物多样性、碳储量、生态水文和养分通量有重要贡献。评估附生植物的多样性格局可以为其群落构建机制以及全球变化背景下附生植物的保护和资源利用提供依据。本文以哀牢山中山湿性常绿阔叶林1.44ha塔吊样地中的附生维管植物为研究对象,综合分析了6种优势乔木宿主植株上附生维管植物的物种丰富度(S)、系统发育多样性(PD)、系统发育结构及其与宿主胸径、树高和物种的相关性。结果表明:哀牢山中山湿性常绿阔叶林311株优势乔木上共调查到26科44属62种附生维管植物。附生植物物种丰富度和系统发育多样性与宿主胸径和树高均呈极显著正相关(P0.05)。变色锥(Castanopsis wattii)和多花含笑(Michelia floribunda)上的附生植物系统发育结构呈发散状态,木果柯(Lithocarpusxylocarpus)和折柄茶上的附生植物系统发育结构呈聚集状态,其余宿主上的附生植物系统发育结构不明显。综上所述,宿主特征包括宿主大小和物种的差异是维持附生维管植物多样性格局的关键,这一结果可为今后从多维度、多角度解析附生维管植物多样性的格局及其维持机制奠定坚实基础。

关键词：附生植物生物多样性系统发育宿主大小林冠塔吊亚热带森林