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High Electrical and Thermal Conductivity of Nano-Ag Paste for Power Electronic Applications

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Acta Metallurgica Sinica(English Letters) 2020年第11期33卷 1543-1555页

作者： Hong-Qiang Zhang hai-lin bai Qiang Jia Wei Guo Lei Liu Gui-Sheng Zou School of Mechanical Engineering and Automation.Beihang University Beijing 100191China Department of Mechanical Engineering Tsinghua UniversityBeijing 100084China

The nano-Ag paste consisted of Ag nanoparticles and organic *** organics would be removed by evaporation or decomposition during *** the sintering temperature was 300℃,the resistivity of sintered bulk was 8.35×10^-6Ωcm,and its thermal conductivity was 247 W m^-1 K^-*** Si/SiC chips and direct bonding copper(DBC)substrates could be bonded by this nano-Ag paste at low *** bonding interface,sintered microstructure and shear strength of Si/SiC chip attachment were investigated by scanning electron microscopy,transmission electron microscopy and shear *** showed that the sintered Ag layer was porous structure and tightly adhered to the electroless nickel immersion gold surface of DBC substrate and formed the continuous Ag–Au interdiffusion *** shear strength of Si and SiC chip attachments was higher than 35 MPa when the sintering pressure was 10 *** fracture occurred inside the sintered Ag layer,and the fracture surface had obvious plastic deformation.

关键词： Nano-Ag paste Sintering process Interfacial microstructure Chip attachment Shear strength

Laser stripping of Ag shell from Au@Ag nanoparticles

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Rare Metals 2021年第12期40卷 3454-3459页

作者： De-Zhi Zhu Jian-Feng Yan Zhen-Wei Liang Jia-Wang Xie hai-lin bai Key Laboratory for Advanced Materials Processing Technology Ministry of Education of ChinaState Key Laboratory of TribologyDepartment of Mechanical EngineeringTsinghua UniversityBeijing 100084China

Metallic nanoparticles(NPs)are a class of important materials with widespread applications due to their chemical stability and high photothermal conversion *** is essential to post-control the morphology and structure of metallic NPs for practical *** processing of metallic NPs has been widely *** of previous studies on the reshaping process have been related to the single metallic NPs,and no attempt has been made to separate the components in bimetallic ***,the stripping of Ag shell from Au@Ag NPs based on ultrafast laser excitation was *** experimental work combined spectrum and microscopy analysis showed the structure transformation of Au@Ag *** the electric field simulation,the stripping of the Ag shell may arise from the electric field effect.

关键词： red image Laser stripping of Ag shell from Au@Ag nanoparticles

Boosting bidirectional sulfur conversion enabled by introducing boron-doped atoms and phosphorus vacancies in Ni2P for lithium-sulfur batteries

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Journal of Energy Chemistry 2025年第1期100卷 760-769页

作者： lin Peng Yu bai Hang Li Meixiu Qu Zhenhua Wang Kening Sun Advanced Research Institute of Multidisciplinary Science Beijing Institute of Technology Beijing Key Laboratory of Chemical Power Source and Green Catalysis School of Chemistry and Chemical Engineering Beijing Institute of Technology

Lithium-sulfur （Li-S） batteries have gained great attention due to the high theoretical energy density and low cost,yet their further commercialization has been obstructed by the notorious shuttle effect and sluggish redox ***,we supply a strategy to optimize the electron structure of Ni2P by concurrently introducing B-doped atoms and P vacancies in Ni2P （Vp-B-Ni2P）,thereby enhancing the bidirectional sulfur *** study indicates that the simultaneous introduction of B-doped atoms and P vacancies in Ni2P causes the redistribution of electron around Ni atoms,bringing about the upward shift of d-band center of Ni atoms and effective d-p orbital hybridization between Ni atoms and sulfur species,thus strengthening the chemical anchoring for lithium polysulfides （LiPSs） as well as expediting the bidirectional conversion kinetics of sulfur ***,theoretical calculations reveal that the incorporation of B-doped atoms and P vacancies in Ni2P selectively promotes Li2S dissolution and nucleation ***,the Li-S batteries with Vp-B-Ni2P-separators present outstanding rate ability of 777 m A h g-1at 5 C and high areal capacity of 8.03 mA h cm-2under E/S of 5μL mg-1and sulfur loading of 7.20 mg *** work elucidates that introducing heteroatom and vacancy in metal phosphide collaboratively regulates the electron structure to accelerate bidirectional sulfur conversion.

关键词： Lithium sulfur batteries

Engineering N3C vacancies in hierarchical porous carbon nitride nanosheets for room temperature ultradeep photocatalytic aerobic oxidative desulfurization

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Science China Chemistry 2025年

作者： Yina Nie Weijie Yang Xin Wang Xiang Li Lele Wei Xiaolin bai lin Liu Feng Fu Jun Wan College of Chemistry & Chemical Engineering Research Institute of Comprehensive Energy Industrial Technology Shaanxi Key Laboratory of Chemical Reaction Engineering Yan'an University Anhui Engineering Research Center of Carbon Neutrality College of Chemistry and Materials Science Anhui Normal University

The production of ultra-low sulfur clean fuels holds global significance for improving energy efficiency and reducing environmental pollution. Photocatalytic aerobic oxidative desulfurization（PODS） offers an attractive approach to efficiently remove refractory heterocyclic aromatic sulfur compounds under mild conditions. However, the sluggish charge dynamics,insufficient molecule activation, and slow mass transfer within photocatalysts restrict the overall desulfurization efficiency,hindering the widespread application of this technology. Herein, we developed a defective g-C3N4（M1U3CN） photocatalyst with bridged N3Cvacancies and hierarchical porous structures to address these limitations. This catalyst not only demonstrates outstanding dibenzothiophene（DBT） removal efficiency of 99.6% for model oil with high conversion and selectivity but also achieves complete sulfur removal from gasoline as well as 96.7% sulfur removal for distilled diesel at room temperature,successfully achieving ultradeep aerobic oxidative desulfurization. The introduction of rich N3Cvacancies and abundant micromeso-macroporous distribution in M1U3CN enhances kinetic efficiencies by promoting charge carrier separation, mass transfer,and molecular activation simultaneously; resulting in exceptional PODS performance. This work provides a collaborative strategy to overcome kinetic challenges in aerobic oxidative desulfurization via defect and structural engineering of the catalyst.

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Deciphering the role of mtH2O2 in hepatic ischemia-reperfusion injury mechanisms with low-background super-resolution fluorogenic probe

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Science China Chemistry 2025年第01期 297-307页

作者： Bin Fang Limin Wang Haoqin Li Jiaxin Zhang Yang Ding Pan Pan Li Bo Peng Hua bai lin Li Frontiers Science Center for Flexible Electronics Xi'an Institute of Flexible Electronics (IFE) and Xi'an Institute of Biomedical Materials &Engineering Northwestern Polytechnical University Institute of Flexible Electronics (IFE Future Technologies) Xiamen University

Hepatic ischemia-reperfusion injury（HIRI） is characterized by mitochondrial dysfunction and oxidative stress. Monitoring mitochondrial hydrogen peroxide（mtH2O2） levels in real-time through super-resolution imaging is crucial for elucidating its distribution in live cells and its mechanism of action during HIRI. However, low-background fluorogenic probes have been overlooked in the context of super-resolution imaging. In this study, we developed a low-background fluorogenic probe（MitoWG） with the potential for super-resolution morphology-correlated mitochondrial identification to track the fluctuates of mtH2O2in HIRI. Activation of the desirable fluorescence properties of the probe by mtH2O2was confirmed using structural illumination microscopy（SIM）, enabling high-quality mitochondrial imaging with exceptional specificity and *** in mtH2O2levels were successfully observed in both cellular and rat models of HIRI. Furthermore, we associated the decline in mitochondrial redox homeostasis with accelerated mtH2O2production during HIRI, which triggered mitophagy deficiency and led to cell death. In conclusion, Mito-WG possesses excellent photophysical and low-background properties for SIM imaging, making it a promising tool for mtH2O2tracking in HIRI research and clinical diagnosis.

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外骨骼下肢康复机器人在脑卒中康复中的应用进展

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中国康复理论与实践 2017年第7期23卷 788-791页

作者：李宏伟张韬冯垚娟林海丹白定群重庆医科大学附属第一医院康复医学科重庆市400016

外骨骼下肢康复机器人根据其辅助步行训练的特点可分为基于平板训练的机器人和平地行走训练机器人。这两类外骨骼下肢康复机器人均在亚急性期和慢性期脑卒中患者康复中得到应用,对脑卒中患者步态、平衡功能的改善,以及下肢运动功能恢复... 详细信息

外骨骼下肢康复机器人根据其辅助步行训练的特点可分为基于平板训练的机器人和平地行走训练机器人。这两类外骨骼下肢康复机器人均在亚急性期和慢性期脑卒中患者康复中得到应用,对脑卒中患者步态、平衡功能的改善,以及下肢运动功能恢复有一定临床意义。

关键词：脑卒中外骨骼下肢康复机器人运动功能康复综述

Ideal Bi‑Based Hybrid Anode Material for Ultrafast Charging of Sodium‑Ion Batteries at Extremely Low Temperatures

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Nano-Micro Letters 2025年第3期17卷 152-167页

作者： Jie bai Jian Hui Jia Yu Wang Chun Cheng Yang Qing Jiang Key Laboratory of Automobile Materials(Jilin University) Ministry of EducationSchool of Materials Science and EngineeringJilin UniversityChangchun 130022People’s Republic of China

Sodium-ion batteries have emerged as competitive substitutes for low-temperature applications due to severe capacity loss and safety concerns of lithium-ion batteries at−20°C or ***,the key capability of ultrafast charging at ultralow temperature for SIBs is rarely ***,a hybrid of Bi nanoparticles embedded in carbon nanorods is demonstrated as an ideal material to address this issue,which is synthesized via a high temperature shock *** a hybrid shows an unprecedented rate performance(237.9 mAh g^(−1)at 2 A g^(−1))at−60℃,outperforming all reported SIB anode *** with a Na_(3)V_(2)(PO_(4))_(3)cathode,the energy density of the full cell can reach to 181.9 Wh kg^(−1)at−40°*** on this work,a novel strategy of high-rate activation is proposed to enhance performances of Bi-based materials in cryogenic conditions by creating new active sites for interfacial reaction under large current.

关键词： Bi nanoparticles High temperature shock High-rate activation Ultrafast charging Low-temperature sodium-ion batteries

Synergistic effect of bonding heterogeneity and phonon localization in introducing excellent thermoelectric properties in layered heteroanionic NdZnSbO material

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Journal of Energy Chemistry 2025年第1期100卷 259-272页

作者： Da Wan Shuwei Tang Shulin bai Xiaodong Li Peng Ai Wanrong Guo Tuo Zheng College of Materials Science and Engineering Liaoning Technical University Faculty of Chemistry Northeast Normal University

Layered rare-earth metal oxides, harnessing the dual properties of oxides and two-dimensional layered materials, exhibit remarkable thermal stability and quantum confinement effects. Therefore, this work adopts the first-principles calculation combined with the Boltzmann transport theory to predict the thermoelectric properties of NdZnSbO compound. The coexistence of weak interlayer van der Waals interactions, robust intralayer ionic bonding, and partial covalent bonding leads to remarkable bonding heterogeneity, which engenders pronounced phonon scattering and imposes constraints on thermal transport along the out-of-plane direction. The weakened chemical bonds induced by the antibonding states, together with the rattling-like behavior of the Zn atom, culminate in the profound anharmonicity in the layered NdZnSbO compound. The weakening bond and heavy element contribute to the softness of phonon modes, which significantly diminishes the phonon group velocity. The redistribution-dominated four-phonon scattering process spans a large optical gap, which effectively reduces the lattice thermal conductivity. The NdZnSbO compound exhibits direct semiconductor characteristic with a bandgap of 0.73 e V by adopting the Heyd-Scuseria-Ernzerhof(HSE06) functional in combination with spin–orbit coupling(SOC) effect. The multi-valley feature of NdZnSbO compound augur favorably for band degeneracy, thus amplifying the power factor. Consequently, an optimal figure-of-merit(ZT) of 3.40 at 900 K is achieved for the n-type NdZnSbO compound. The present study delves deeply insights into the origins for the low thermal conductivity of NdZnSbO compound and proposes an optimization scheme to enhance overall thermoelectric performance.

关键词： Bond strength (chemical)

Effect of pouring height on the solidified microstructure of AlSi7Mg alloy

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Journal of University of Science and Technology Beijing 2006年第4期13卷 324-328页

作者： Weimin Mao Yuelong bai hai lin Materials Science and Engineering School University of Science and Technology Beijing Beijing 100083 China

The effect of different pouring heights and evenly soaking process in the liquidus and solidus range on the solidified microstructure of AlSi7Mg alloy has been studied. The results show that if the pouring temperature is 630 or 650℃ and the pouring height is 40 mm, the microstructure of the solidified melt is not homogeneous and there are many rosette-like primary α-Al grains. But if the pouring height is increased to 400 mm, the solidified microstructure becomes more homogeneous and favorable to obtain spherical primary α-Al grains in the solidified melt. With further being evenly soaked in the liquidus and solidus range for some time, the temperature difference between the melt center and the melt periphery can be controlled within ±2℃ and the primary α-Al grains will evolve into more spherical grains. The theoretical analysis indicates that the higher pouring height promotes the melt flow motion and makes the temperature field in the melt more homogeneous and restrains the large rosette primary α-Al grains. This flow motion can also promote the ripening effect and the primary α-Al grains in the melt are gradually changed into spherical grains. It can be concluded from the experiments that pouring at an appropriate superheat and from a proper height is a good new method for preparing the semisolid slurry of AlSi7Mg alloy, its process control is easy and the preparation cost is lower.

关键词： AlSi7Mg alloy semisolid pouring height solidification flow motion