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Effect of Thermal Cycling on Properties and Microstructure of SnAgCuCe Soldered Joints in QFP Devices

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Chinese Journal of Mechanical Engineering 2011年第4期24卷 561-566页

作者： zhang liang xue songbai GAO Lili zeng guang YU Shenglin SHENG Zhong College of Materials Science and Technology Nanjing University of Aeronautics and Astronautics Nanjing 210016 China School of Mechanical ＆ Electrical Engineering Xuzhou Normal University Xuzhou 221116 China The 14th Research Institute China Electronics Technology Group Corporation Nanjing 210013 China

Increasing global concern about the environment is bringing regulatory （European directives） and consumer （＂green products＂） pressure on the electronics industry in Europe and Japan to reduce or completely eliminate the use of lead （Pb） in products. Among all lead-free solder alloys, SnAgCu solder system, which has better thermo-mechanical properties compared with those of SnPb solder, is proven to be one of the promising candidates for electronic assembly. Previous work also revealed that adding a small amount of rare earth Ce into SnAgCu solder can visibly improve the properties and inhibit the excessive growth of the intermetallic compound layer. Thermal fatigue properties of SnAgCuCe soldered joints in QFP devices under thermal conditions have been investigated by finite element method and experiments. Based on creep model of low stress and high stress, corresponding creep subroutine was established for simulating the stress and strain response of SnAgCuCe soldered joint from -55 ℃ to 125 ℃, and fatigue life was calculated using creep fatigue life prediction equation. Moreover, thermal cycling experiments were conducted, the experimental results were found to be close to the simulated results. In addition, the tensile force of SnAgCuCe soldered joints decreased with increasing number of thermal cycles, and the fracture mechanism transformed from toughness fracture to brittle intergranular fracture. Moreover the tensile force changes and fracture microstructure evolution could benefit the quantitative evaluations of the mechanical performances of lead-free soldered joints under thermal cycling loadings.

关键词： finite element method creep equation thermal cycling fatigue life

Comprehensive evaluation of sintering basic characteristics of iron ore based on grey relational analysis

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Journal of Iron and Steel Research International 2019年第7期26卷 691-696页

作者： Dong-hui Liu Jun-hua Li Yue peng Jian-liang zhang guang-wei Wang Xun xue School of Environment Tsinghua University Beijing 100084 China School of Metallurgy and Ecological Engineering University of Science and Technology Beijing Beijing 100083 China Beijing Shenwu Environment & Energy Technology Co. Ltd. Beijing 102200 China

Sintering basic characteristics of fourteen iron ores were comprehensively evaluated using micro-sinter and grey relational analysis methods. The results show that magnetite has a low assimilability, high bonding phase strength, and high crystal strength. Hematite presents a good assimilability, while limonite exhibits a strong assimilability, but the bonding phase strength and crystal strength of these two kinds of iron ores are comparatively low. Great difference in liquid flowability exists for the same kind of iron ores. When the assimilation temperature of the sinter mixture is too high, limonite can be added;when the bonding phase strength or crystal strength of the sinter mixture is too low, magnetite can be added. The liquid fluidity of the sinter mixture can be adjusted according to the ratios of corresponding iron ores. Grey relational analysis is an effective method to evaluate the comprehensive sintering characteristics of iron ores, which can provide theoretical basis for the purchasing department of the steel enterprises.

关键词： Iron ore Basic characteristics Sinter Grey relational analysis Iron ore purchasing Ore proportioning optimization

Correlation of RUNX3 expression with microvessel density in colorectal adenocarcinoma tissues and clinical significance

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Asian Pacific Journal of Tropical Medicine 2017年第1期10卷 94-97页

作者： Jun xue xue-liang Wu Xian-Tao Huang Ming Qu Fei Guo guang-Yuan Sun peng-Cheng zhang Lei Han Li-Ming Pan First Affiliated Hospital Hebei North UniversityZhangjiakou 075000HeBeiChina

Objective: To study the expression of RUNX3 in colorectal adenocarcinoma tissues and its correlation with microvessel density(MVD),and investigate the clinical pathological prognostic significance of RUNX3 and MVD in patients with colorectal cancer,Methods: The expression value of RUNX3 and MVD in 70 specimens' colorectal adenocarcinoma tissues were detected by immunohistochemistry staining technique,The correlation between their expression and the clinicopathologic features was also investigated,Results: The expression value of RUNX3 and the positive rates of RUNX3 in colorectal adenocarcinoma tissues were 3.25±1.14 and 25.71%(18/70),The expression value of MVD in colorectal adenocarcinoma tissues was 13.14±3.23,Expression of RUNX3 and MVD value were correlated with CEA,serosal invasion,liver metastasis,lymph node metastasis,and TNM stage(P<0.01),The expression value of RUNX3 had negative correlations with that of MVD,Conclusions: The high expression of RUNX3 could inhibit tumor microvascular generation in order to have negative control response on invasion and distant metastasis.

关键词： Colorectal neoplasms RUNX3 Microvessel density Clinical significance

Photobiomodulation provides neuroprotection through regulating mitochondrial fission imbalance in the subacute phase of spinal cord injury

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Neural Regeneration Research 2023年第9期18卷 2005-2010页

作者： Xin Li Xuan-Kang Wang Zhi-Jie Zhu Zhuo-Wen liang peng-Hui Li Yang-guang Ma Tan Ding Kun Li Xiao-Shuang Zuo Cheng Ju Zhi-Hao zhang Zhi-Wen Song Hui-Lin Quan Jia-wei zhang liang Luo Zhe Wang xue-Yu Hu Department of Orthopedics Xijing HospitalFourth Military Medical UniversityXi’anShaanxi ProvinceChina 2967 Hospital of People’s Liberation Army Joint Logistic Support Force DalianLiaoning ProvinceChina

Increasing evidence indicates that mitochonarial lission imbalance plays an important role in derayed neuronal cell death. Our previous study round that photo biomodulation improved the motor function of rats with spinal cord ***,the precise mechanism remains *** investigate the effect of photo biomodulation on mitochondrial fission imbalance after spinal cord injury,in this study,we treated rat models of spinal co rd injury with 60-minute photo biomodulation(810 nm,150 mW) every day for 14 consecutive *** electron microscopy results confirmed the swollen and fragmented alte rations of mitochondrial morphology in neurons in acute(1 day) and subacute(7 and 14 days) *** biomodulation alleviated mitochondrial fission imbalance in spinal cord tissue in the subacute phase,reduced neuronal cell death,and improved rat posterior limb motor function in a time-dependent *** findings suggest that photobiomodulation targets neuronal mitochondria,alleviates mitochondrial fission imbalance-induced neuronal apoptosis,and thereby promotes the motor function recovery of rats with spinal cord injury.

关键词： low-level laser therapy mitochondria mitochondrial dynamics mitochondrial fission imbalance neuron photobiomodulation secondary injury spinal cord injury

细间距器件SnAgCu焊点热疲劳性能研究(英文)

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稀有金属材料与工程 2010年第3期39卷 382-387页

作者：张亮薛松柏皋利利曾广禹胜林盛重南京航空航天大学江苏南京210016 中国电子科技集团第十四研究所江苏南京210013

通过试验和数值模拟两种方法分析细间距器件SnAgCu焊点的热疲劳寿命。采用-55～125℃温度循环试验,发现SnAgCu焊点疲劳寿命约为1150次。基于Anand方程和Wong方程两种本构模型,针对两类疲劳寿命预测方程进行对比研究。结果显示,基于两种... 详细信息

通过试验和数值模拟两种方法分析细间距器件SnAgCu焊点的热疲劳寿命。采用-55～125℃温度循环试验,发现SnAgCu焊点疲劳寿命约为1150次。基于Anand方程和Wong方程两种本构模型,针对两类疲劳寿命预测方程进行对比研究。结果显示,基于两种模型计算的SnAgCu焊点应力时间历程曲线具有相类似的趋势,但是应力值有较大差别。针对两类疲劳寿命预测方程,结合试验研究分析焊点的疲劳寿命,基于Wong方程结合双蠕变模型计算的疲劳寿命值和试验结果吻合良好,而基于Anand方程结合Engelmaier修正的Coffin-Mason方程计算的疲劳寿命略高于试验结果。

关键词：本构方程:细间距器件有限元模型疲劳寿命方程可靠性

Exposure Effects of Terahertz Waves on Primary Neurons and Neuron-like Cells Under Nonthermal Conditions

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Biomedical and Environmental Sciences 2019年第10期32卷 739-754页

作者： TAN Sheng Zhi TAN peng Cheng LUO Lan Qing CHI Yun liang YANG Zi Long ZHAO xue Long ZHAO Li DONG Ji zhang Jing YAO Bin wei XU Xin Ping TIAN guang CHEN Jian Kui WANG Hui peng Rui Yun Beijing Institute of Radiation Medicine Beijing 100850China School of Pharmaceutical Sciences Tsinghua UniversityBeijing 100084China Inner Mongolia University for the Nationalities Yakeshi 022150Inner MongoliaChina General Hospital of Northern Theater Command Shenyang 110000LiaoningChina State Key Laboratory of Pathogen and Biosecurity Beijing Institute of Microbiology and EpidemiologyBeijing 100071China Fifth Medical Center Chinese People's Liberation Army General HospitalBeijing 100071China

Objective This study aimed to explore the potential effects of terahertz(THz) waves on primary cultured neurons from 4 rat brain regions(hippocampus, cerebral cortex, cerebellum, and brainstem)and 3 kinds of neuron-like cells(MN9 D, PC12, and HT22 cells) under nonthermal *** THz waves with an output power of 50(0.16 THz) and 10(0.17 THz) m W with exposure times of 6 and 60 min were used in this study. Analysis of temperature change, neurite growth, cell membrane roughness, micromorphology, neurotransmitters and synaptic-related proteins(SYN and PSD95) was used to evaluate the potential *** Temperature increase caused by the THz wave was negligible. THz waves induced significant neurotransmitter changes in primary hippocampal, cerebellar, and brainstem neurons and in MN9 D and PC12 cells. THz wave downregulated SYN expression in primary hippocampal neurons and downregulated PSD95 expression in primary cortical *** Different types of cells responded differently after THz wave exposure, and primary hippocampal and cortical neurons and MN9 D cells were relatively sensitive to the THz waves. The biological effects were positively correlated with the exposure time of the THz waves.

关键词： Neuron brainstem cortex

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细间距器件焊点力学性能与数值模拟

焊接学报 2008年第10期29卷 89-92页

作者：张亮薛松柏曾广韩宗杰禹胜林南京航空航天大学材料科学与技术学院南京210016 中国电子科技集团第十四研究所南京210013

采用再流焊方法对细间距器件进行钎焊试验,针对使用SnAgCu和SnPb两种钎料对应的焊点进行了研究。结果表明,SnAgCu焊点的拉力明显高于SnPb焊点,说明SnAgCu对应焊点的抗拉强度更高。对焊点断口组织分析发现,SnAgCu焊点拉伸断裂方式为韧性... 详细信息

采用再流焊方法对细间距器件进行钎焊试验,针对使用SnAgCu和SnPb两种钎料对应的焊点进行了研究。结果表明,SnAgCu焊点的拉力明显高于SnPb焊点,说明SnAgCu对应焊点的抗拉强度更高。对焊点断口组织分析发现,SnAgCu焊点拉伸断裂方式为韧性断裂,而SnPb焊点的断裂方式兼有脆性断裂和韧性断裂的特征。运用非线性有限元模拟,针对焊点在温度循环载荷作用下的力学性能分析,发现SnAgCu焊点的应力应变以及非线性应变能明显小于SnPb焊点对应的数值。说明SnAgCu焊点的可靠性明显高于SnPb焊点。模拟结果和试验研究结果吻合,该研究为无铅钎料的进一步研究提供理论指导。

关键词：再流焊细间距器件断口组织非线性有限元

Solar X-ray and EUV imager on board the FY-3E satellite

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Light(Science & Applications) 2022年第12期11卷 2939-2951页

作者： Bo Chen Xiao-Xin zhang Ling-Ping He Ke-Fei Song Shi-Jie Liu guang-Xing Ding Jin-Ping Dun Jia-wei Li Zhao-Hui Li Quan-Feng Guo Hai-Feng Wang Xiao-Dong Wang Yun-Qi Wang Hong-Ji zhang guang zhang Zhen-wei Han Shuang dai Pei-Jie zhang liang Sun Yang Liu software engineer peng Wang Kun Wu Chen Tao Shi-Lei Mao Gui Mei liang Yang Li-Heng Chen Chun-Yang Han Bin Huang Yang Liu mechanical engineer Shuai Ren peng Zhou Ze-Xiwei Xiao-xue zhang Yue zhang Xin Zheng Yang Wang Ya Chen Jing-Jiang Xie Fei He Qiao Song wei-Guo Zong Xiu-Qing Hu peng zhang Jing-Song Wang Zhong-Dong Yang Changchun Institute of Optics Fine Mechanics and PhysicsChinese Academy of SciencesChangchunChina State Key Laboratory of Applied Optics Chinese Academy of SciencesChangchunChina National Satellite Meteorological Center China Meteorological AdministrationBeijingChina Key Laboratory of Space Weather National Center for Space WeatherChina Meteorological AdministrationBeijingChina Innovation Center for Fengyun Meteorological Satellite(FYSIC) BeijingChina Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijingChina

The solar X-ray and Extreme Ultraviolet Imager(X-EUVI),developed by the Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences(CIOMP),is the first space-based solar X-ray and Extreme ultraviolet(EUV)imager of China loaded on the Fengyun-3E(FY-3E)satellite supported by the China Meteorological Administration(CMA)for solar *** started work on July 11,2021,X-EUVI has obtained many solar *** instrument employs an innovative dual-band design to monitor a much larger temperature range on the Sun,which covers 0.6-8.0 nm in the X-ray region with six channels and 19.5 nm in the EUV region.X-EUVI has a field of view of 42′,an angular resolution of 2.5″per pixel in the EUV band and an angular resolution of 4.1″per pixel in the X-ray *** instrument also includes an X-ray and EUV irradiance sensor(X-EUVS)with the same bands as its imaging optics,which measures the solar irradiance and regularly calibrates the solar *** radiometric calibration of X-EUVS on the ground has been completed,with a calibration accuracy of 12%.X-EUVI is loaded on the FY-3E satellite and rotates relative to the Sun at a uniform ***-field calibration is conducted by utilizing successive rotation solar *** agreement between preliminarily processed X-EUVI images and SDO/AIA and Hinode/XRT images indicates that X-EUVI and the data processing algorithm operate properly and that the data from X-EUVI can be applied to the space weather forecast system of CMA and scientific investigations on solar activity.

关键词： image instrument Solar

Site-testing at Muztagh-ata site Ⅲ:temperature inversion in surface-layer atmosphere

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Research in Astronomy and Astrophysics 2020年第6期20卷 185-192页

作者： Jing Xu Ali Esamdin Guo-Jie Feng guang-Xin Pu Yi Hu Ke-liang Hu Xu Yang Jin-Xin Hao Yan-Jie xue Xu Zhou Shu-Guo Ma Abudusaimaitijiang Yisikandee Le-Tian Wang Xuan zhang Chun-Hai Bai peng wei liang Ming Lu Ma Jin-Zhong Liu Yun-Ying Jiang Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China University of Chinese Academy of Sciences Beijing 100049China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China

In this article,we present detailed seasonal,monthly and daily statistics of temperature difference in the surface layer at the Muztagh-ata site based on the temperature measurements at two heights of 2 m and6 *** find that temperature inversion occurs frequently at our site during nighttime,especially during the cold *** temperature inversion always represents stable atmospheric turbulence,which is crucial for an optical *** analyzing the behavior of temperature inversion and its correlation with wind and cloud amount,one conclusion can be made that radiation inversion is the main reason for the existence of temperature inversion in the surface-layer at the Muztagh-ata site.

关键词： site testing atmospheric turbulence temperature inversion