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一种动态热环境中印制电路板微形变控制研究

印制电路信息 2024年第S1期32卷 9-18页

作者：唐昌胜郭国栋陈支武深南电路股份有限公司广东深圳518117

随着电子系统的复杂度持续提升,作为电子系统承载的印制电路板在集成度、布线密度以及轻薄化方向快速演进,越来越多种类的芯片直接贴附于印制电路板上,用以实现轻薄化、提升集成度。由于芯片本身轻薄特性,对热应力、机械应力等非常敏感... 详细信息

随着电子系统的复杂度持续提升,作为电子系统承载的印制电路板在集成度、布线密度以及轻薄化方向快速演进,越来越多种类的芯片直接贴附于印制电路板上,用以实现轻薄化、提升集成度。由于芯片本身轻薄特性,对热应力、机械应力等非常敏感,且印制电路板在SMT(Surface Mounted Technology:贴片指在印制电路板表面进行元器件或芯片贴装的技术)过程中处于长时间的动态热环境中,微形变不可避免,当未经封装的芯片在SMT制程中贴附于印制电路板表面上时,极易因为动态热环境中的微形变导致芯片断裂或起翘等失效。本文经过材料、结构、孔位等因素研究,可以通过前端设计的优化,实现印制电路板在动态热环境中的微形变有效控制,大幅降低芯片贴装到印制电路板上的起翘/断裂等失效,效果显著。

关键词：印制电路板芯片起翘裂纹材料设计控制改善

Adaptive cross-fusion learning for multi-modal gesture recognition

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Virtual Reality & Intelligent Hardware 2021年第3期3卷 235-247页

作者： Benjia ZHOU Jun WAN Yanyan LIANG guodong guo Macao University of Science and Technology Macao 999078China National Laboratory of Pattern Recognition Institute of AutomationChinese Academy of SciencesBeijing 100190China Baidu Research Beijing 100193Chinaand National Engineering Laboratory for Deep Learning Technology and ApplicationBeijing 100193China

Background Gesture recognition has attracted significant attention because of its wide range of potential *** multi-modal gesture recognition has made significant progress in recent years,a popular method still is simply fusing prediction scores at the end of each branch,which often ignores complementary features among different modalities in the early stage and does not fuse the complementary features into a more discriminative *** This paper proposes an Adaptive Cross-modal Weighting(ACmW)scheme to exploit complementarity features from RGB-D data in this *** scheme learns relations among different modalities by combining the features of different data *** proposed ACmW module contains two key functions:(1)fusing complementary features from multiple streams through an adaptive one-dimensional convolution;and(2)modeling the correlation of multi-stream complementary features in the time *** the effective combination of these two functional modules,the proposed ACmW can automatically analyze the relationship between the complementary features from different streams,and can fuse them in the spatial and temporal *** Extensive experiments validate the effectiveness of the proposed method,and show that our method outperforms state-of-the-art methods on IsoGD and NVGesture.

关键词： Gesture recognition Multi-modal fusion RGB-D

Regulation of osteoblast functions on titanium surfaces with different micro/nanotopographies and compositions

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Science China(Technological Sciences) 2019年第4期62卷 559-568页

作者： HE Peng WANG XiaoLan NING ChengYun LIU XiaoWei LI Mei XU HaiDong guo guodong MAO GuangPing LIU Gang XU Bin ZHANG Yu ZHAO JianNing Department of Orthopedics Nanjing General Hospital of Nanjing Military Command of PLA Department of Orthopedics Guangdong General Hospital Guangdong Academy of Medical Sciences School of Materials Science and Engineering South China University of Technology

Surface modification of medical implants is considered as an effective method to improve cellular behaviors and the integration of tissues with materials. Titanium(Ti)-based materials with four different micro/nano-structures and compositions were prepared by acid etching, electrochemical anodization and alkali-heat treatment. The surface morphologies and compositions of the different surface-modified Ti materials were characterized by field-emission scanning electron microscopy(FE-SEM),atomic force microscopy(AFM) and X-ray diffraction(XRD). The effects of the micro/nano structured and compositions of the surfaces on cellular responses were investigated in vitro by observing the morphology, adhesion, proliferation and osteogenic differentiation of osteoblasts. To further investigate the underlying mechanisms, an RT-PCR assay was performed to analyze the expression levels of cell adhesion-related genes. Our results indicated that the nanosized structure and anatase composition could promote the adhesion and proliferation of MC3T3-E1 pre-osteoblast, as well as alkaline phosphatase activity and extracellular matrix mineralization via the integrin-FAK signaling pathway. Taken together, our innovation presented in this work demonstrated that the surface nano-structure design and composition of biomedical implants can be modified of for future orthopaedic applications.

关键词： osteoblast functions micro/nanotopography composition titanium

Experimental Study on the Axial Compression Performance of Bamboo Scrimber Columns Embedded with Steel Reinforcing Bars

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Structural Durability & Health Monitoring 2024年第6期18卷 805-833页

作者： Xueyan Lin Mingtao Wu guodong Li Nan guo Lidan Mei College of Civil Engineering and Transportation Northeast Forestry UniversityHarbin150000China Department of Building Engineering College of Civil EngineeringTongji UniversityShanghai200092China College of Transportation and Civil Engineering Fujian Agriculture and Forestry UniversityFuzhou350002China

In this paper,a new type of bamboo scrimber column embedded with steel bars(rebars)was proposed,and the compression performance was improved by pre-embedding rebars during the preparation of the *** effects of the slenderness ratio and the reinforcement ratio on the axial compression performance of reinforced bamboo scrimber columns were studied by axial compression tests on 28 *** results showed that the increase in the slenderness ratio had a significant negative effect on the axial compression performance of the *** the slenderness ratio increased from 19.63 to 51.96,the failure mode changed from strength failure to buckling failure,and the maximum bearing capacity decreased by 43.03%.The axial compression performance of the reinforced bamboo scrimber columns did not significantly improve at a slenderness ratio of 19.63,but the opposite was true at slenderness ratios of 36.95 and *** the reinforcement ratio increased from 0%to 4.52%,the bearing capacity of those with a slenderness ratio of 51.96 increased by up to 16.99%,and the stiffness and ductility were also ***,based on existing specifications,two modification parameters,the overall elastic modulus Ec and the combined strength fcc,were introduced to establish a calculation method for the bearing capacity of the reinforced bamboo scrimber *** calculation results were compared with the test results,and the results showed that the proposed calculation models can more accurately predict the bearing capacity.

关键词： Bamboo scrimber column steel bar axial compression performance theoretical model

Investigation of radionuclide～(63)Ni(Ⅱ) sequestration mechanisms on mordenite by batch and EXAFS spectroscopy study

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Science China Chemistry 2012年第4期55卷 632-642页

作者： YANG ShiTong,SHENG guodong,guo ZhiQiang,TAN XiaoLi,XU JinZhang & WANG XiangKe Key Laboratory of Novel Thin Film Solar Cells,Institute of Plasma Physics,Chinese Academy of Sciences,Hefei 230031,China Key Laboratory of Novel Thin Film Solar Cells Institute of Plasma Physics Chinese Academy of Sciences Hefei China

The sorption behavior and microscopic sequestration mechanisms of radionuclide 63Ni（II） on mordenite as a function of aging time, ionic srength, initial 63Ni（II） concentrations, solid content and coexistent electrolyte ions were investigated by the combination of batch and EXAFS techniques. Macroscopic experiment results show that the sorption of 63Ni（II） is dependent on ionic strength at pH〈7, and independent of ionic strength at pH〉7. The sorption percentage of 63Ni（II） on mordenite increases with increasing solid content, while the sorption capacity decreases as solid content increases. The presence of different electrolyte ions can enhance or inhibit the sorption of Ni（II） on mordenite in various degrees. EXAFS analysis results of the sam- ples under three different ionic strengths suggest that the retained 63Ni（II） in these samples exists in an octahedral environment with six water ligands. In the initial period of rapid uptake, the sorption of 63Ni（II） is dominated by the formation of innersphere surface complexes. As aging time increases, 63Ni（II） sequestration behavior tends to be mainly controlled by the formation of Ni phyllosilicate coprecipitates and/or Ni（OH）2（s） precipitates. Results for the second shell fit of the sample prepared at an initial 63Ni（II） concentration of 100 mg/L indicate the possible formation of Ni polynuclear surface complexes. Both the macroscopic sorption data and the molecular level evidence of 63Ni（II） surface speciation at the mordenite/water interfaces should be factored into better predictions of the mobility and bioavailability of 63Ni（II） in environment mediums.

关键词： mordenite – 63Ni(II) – aging time – initial concentration – EXAFS analysis

High Power GaN Doubler with High Duty Cycle Pulse Based on Local Non-reflection Design

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Chinese Journal of Electronics 2024年第5期33卷 1196-1203页

作者： Yazhou DONG Tianchi ZHOU Shixiong LIANG guodong GU Hongji ZHOU Jianghua YU Hailong guo Yaxin ZHANG School of Electronic Science and Engineering University of Electronic Science and Technology of China National Key Laboratory of Solid-State Microwave Devices and Circuits Hebei Semiconductor Research Institute

The study focuses on the development of gallium nitride(GaN) Schottky barrier diode(SBD) frequency doublers for terahertz technology. The low conversion efficiency of these doublers limits their practical applications. To address this challenge, the paper proposes a multi-objective local no-reflection design method based on a three-dimensional electromagnetic structure. The method aims to improve the coupling efficiency of input power and reduce the reflection of power output. Experimental results indicate that the proposed method significantly improves the performance of GaN SBD frequency doublers, achieving an efficiency of 16.9% and a peak output power of 160mW at 175 GHz. These results suggest that the method can contribute to the further development of GaN SBD frequency doublers for terahertz technology.

关键词： Couplings Schottky diodes Design methodology Schottky barriers Terahertz materials Power system harmonics Reflection Gallium nitride Frequency doubler Multi-objective optimization Local non-reflection design FREQUENCY DOUBLER RADAR

The Magnaporthe oryzae effector Avr-PikD suppresses rice immunity by inhibiting an LSD1-like transcriptional activator

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The Crop Journal 2024年第2期12卷 482-492页

作者： Jiayuan guo Yiling Wu Jianqiang Huang Kaihui Yu Meilian Chen Yijuan Han Zhenhui Zhong guodong Lu Yonghe Hong Zonghua Wang Xiaofeng Chen Fujian Universities Engineering Research Center of Marine Biology and Drugs Fuzhou Institute of OceanographyCollege of Geography and OceanographyMinjiang UniversityFuzhou 350108FujianChina Rice Research Institute Fujian Academy of Agricultural SciencesFuzhou 350018FujianChina Ministerial and Provincial Joint Innovation Center for Safety Production of Cross-Strait Crops Minjiang UniversityFuzhou 350108FujianChina State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops College of Plant ProtectionFujian Agriculture and Forestry UniversityFuzhou 350002FujianChina

Avirulence effectors(Avrs),encoded by plant pathogens,can be recognized by plants harboring the corresponding resistance proteins,thereby initiating effector-triggered immunity(ETI).In susceptible plants,however,Avrs can function as effectors,facilitating infection via effector-triggered susceptibility(ETS).Mechanisms of Avr-mediated ETS remain largely *** we report that the Magnaporthe oryzae effector Avr-PikD enters rice cells via the canonical cytoplasmic secretion pathway and suppresses rice basal ***-PikD interacts with an LSD1-like transcriptional activator AKIP30 of rice,and AKIP30 is also a positive regulator of rice immunity,whereas Avr-PikD impedes its nuclear localization and suppresses its transcriptional *** summary,*** delivers Avr-PikD into rice cells to facilitate ETS by inhibiting AKIP30-mediated transcriptional regulation of immune response against ***.

关键词： Magnaporthe oryzae Avirulence effector Avr-PikD Effector-triggered susceptibility Rice immunity Transcriptional activator

Uniformity Control of Scanned Beam in 300 MeV Proton and Heavy Ion Accelerator Complex at SESRI

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原子能科学技术 2024年第4期58卷 705-713页

作者： HOU Lingxiao YUAN Youjin SHEN guodong RUAN Shuang LIU Jie ZHU Yunpeng WANG Geng guo Hongliang LYU Mingbang GAO Daqing XU Zhiguo SHENG Lina YANG Jiancheng Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China

In recent years,heavy ion accelerator technology has been rapidly developing worldwide and widely applied in the fields of space radiation simulation and particle ***,a very high uniformity in the irradiation area is required for the extracted ion beams,which is crucial because it directly affects the experimental precision and therapeutic ***,ultra-large-area and high-uniformity scanning are crucial requirements for spacecraft radiation effects assessment and serve as core specification for beamline terminal *** the 300 MeV proton and heavy ion accelerator complex at the Space Environment Simulation and Research Infrastructure(SESRI),proton and heavy ion beams will be accelerated and ultimately delivered to three irradiation *** order to achieve the required large irradiation area of 320 mm×320 mm,horizontal and vertical scanning magnets are used in the extraction beam ***,considering the various requirements for beam species and energies,the tracking accuracy of power supplies(PSs),the eddy current effect of scanning magnets,and the fluctuation of ion bunch structure will reduce the irradiation *** mitigate these effects,a beam uniformity optimization method based on the measured beam distribution was proposed and applied in the accelerator complex at *** the experiment,the uniformity is successfully optimized from 75%to over 90%after five iterations of adjustment to the PS *** this paper,the method and experimental results were introduced.

关键词： heavy ion accelerator beam uniformity scanning magnet MIC

电力市场环境下基于深度强化学习的微网能量管理系统实时自动控制算法

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电测与仪表 2021年第9期58卷 78-88页

作者：郭国栋龚雁峰新能源电力系统国家重点实验室(华北电力大学) 北京102206

作为多类分布式能源的集成者,微网在促进清洁低碳能源发展方面有巨大潜力。然而,可再生能源出力的不确定性给微网的管理带来了挑战,同时也将这种不确定因素带给外部电网。文章基于实时市场,构建了一个包含新能源机组、传统机组和需求响... 详细信息

作为多类分布式能源的集成者,微网在促进清洁低碳能源发展方面有巨大潜力。然而,可再生能源出力的不确定性给微网的管理带来了挑战,同时也将这种不确定因素带给外部电网。文章基于实时市场,构建了一个包含新能源机组、传统机组和需求响应资源的微网环境,并采用了能够利用环境信息的深度确定性策略梯度算法,这种无模型(Model-free)的强化学习算法有助于充分利用累积的数据信息,能够更好地适应不确定环境,在连续的状态空间和动作空间中进行学习提升。仿真结果表明,所提算法能够有效应对微网中的不确定因素,降低微网运行成本。

关键词：微网深度强化学习电力市场可再生能源