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Effects of Cover Sheets on the Nugget Growth and Fracture Behavior of Resistance Spot Welded Q&P980 Steel Joints

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Chinese Journal of Mechanical Engineering 2022年第4期35卷 360-373页

作者： Zhanxiang Ling ting Chen liang Kong Min Wang Shanghai Key Laboratory of Materials Laser Processing and Modifcation Shanghai Jiao Tong UniversityShanghai 200240China

The resistance spot weldability of galvanized ultra-high-strength steels is not satisfed,the joints are prone to interfacial fracture and the weldable current range is *** solve the problems,a novel method called resistance spot welding with double-sided cover sheets was introduced to weld a galvanized Q&P980 steel with the thickness of 1.2 *** thin SPCC mild steel sheets were chosen as cover sheets and were placed symmetrically at both sides between the Q&P980 steels and the electrodes,then the RSW process was carried *** with the traditional RSW method,the joints obtained by using the novel method achieved larger tensile shear strength and energy absorption,which increased by 26.9%and 52.6%,*** increasing the welding current,the failure mode transferred from interfacial fracture to nugget pull-out fracture or base metal tearing *** contrast,the joints always showed interfacial fracture without cover *** improvement of the joint performance was mainly attributed to the enlargement of the *** the help of fnite element simulation,it was found that the cover sheets helped increase the contact area and reduced the current density during welding,which postponed the expulsion,and a larger area could be evenly *** application of the novel method can be easily extended to the resistance spot welding of other ultra-high-strength steels with various thicknesses.

关键词： Resistance spot welding Q&P980 steel Cover sheet Mechanical property

Processing of a low-costγ-γ'NiPtAl coating with improved oxidation resistance

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Rare Metals 2024年第6期43卷 2832-2841页

作者： Yan Jiang liang-liang Wei Jian He Hong-bo Guo School of Materials Science and Engineering Beihang UniversityBeijing 100191China Key Laboratory of High-Temperature Structural Materials and Protective Coatings Ministry of Industry and Information TechnologyBeihang UniversityBeijing 100191China

A novelγ-γ'(Ni solid solution—Ni_(3)Al)NiPtAl coating was produced on advanced single-crystal(SC)superalloy N5 by electroplating of a thin Pt coating with~3μm in thickness followed by heat treatment at 1000℃in *** comparison,a traditionalγ-γ'NiPtAl coating was also produced by electroplating of a thick Pt coating with~6μm in thickness followed by heat treatment at 1100℃in *** novel coating has a mass gain of~0.5 mg·cm^(-2)after 100 h 1-h cyclic oxidation at 1150℃,showing better oxidation resistance than the traditional *** oxide scale mostly consisting ofα-Al_(2)O_(3)grew on the novel coating because the element Cr from the SC alloy substrate contributes to the formation ofα-Al_(2)O_(3).Pt content in the novel coating has significant effect on the oxidation *** optimized Pt content in the coating is about 16 at%,which is helpful to reduce the diffusion of harmful elements from the substrate into the coating but also to reduce the cost of the coating.

关键词： γ-γ'NiPtAl coating Platinum Oxidation Al_(2)O_(3) Superalloy

New approaches in agent-based modeling ofcomplex financial systems

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Frontiers of physics 2017年第6期12卷 115-126页

作者： ting-ting Chen bo Zheng Yan Li Xiong-Fei Jiang Department of Physics Zhejiang University Hangzhou 310027 China Collaborative Innovation Center of Advanced Microstructures Nanjing 210093 China

Agent-based modeling is a powerful simulation technique to understand the collective behavior and microscopic interaction in complex financial systems. Recently, the concept for determining the key parameters of agent-based models from empirical data instead of setting them artificially was sug- gested. We first review several agent-based models and the new approaches to determine the key model parameters from historical market data. Based on tile agents＇ behaviors with heterogeneous personal preferences and interactions, these models are successful in explaining the microscopic origi- nation of the temporal and spatial correlations of financial markets. We then present a novel paradigm combining big-data analysis with agent-based modeling. Specifically, from internet query and stock market data, we extract the information driving forces and develop an agent-based model to simulate the dynamic behaviors of complex financial systems.

关键词： econophysics complex systems

CDM: Content Diffusion Model for Information-Centric Networks

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Journal of Computer Science & Technology 2021年第6期36卷 1431-1451页

作者： bo Chen liang Liu Hua-Dong Ma Beijing Key Laboratory of Intelligent Telecommunications Software and Multimedia Beijing University of Posts and TelecommunicationsBeijing 100876China School of Computer Science Beijing University of Posts and TelecommunicationsBeijing 100876China

This paper proposes the Content Diffusion Model(CDM)for modeling the content diffusion process in information-centric networking(ICN).CDM is inspired by the epidemic model and it provides a method of theoretical quantitative analysis for the content diffusion process in ***,CDM introduces the key functions to formalize the key factors that influence the content diffusion process,and thus it can construct the model via a simple but efficient ***,we derive CDM by using different combinations of those key factors and put them into several typical ICN scenarios,to analyze the characteristics during the diffusion process such as diffusion speed,diffusion scope,average fetching hops,changing and final state,which can greatly help to analyze the network performance and application design.A series of experiments are conducted to evaluate the efficacy and accuracy of *** results show that CDM can accurately illustrate and model the content diffusion process in ICN.

关键词： information-centric networking content diffusion modeling

BDNF rescues prefrontal dysfunction elicited by pyramidal neuron-specific DTNBP1 deletion in vivo

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Journal of Molecular Cell Biology 2017年第2期9卷 117-131页

作者： Wen Zhang Kathryn M. Daly bo liang Lifeng Zhang Xuan Li Yun Li Da-ting Lin Intramural Research Program National Institute on Drug Abuse National Institutes of Health 333 CasseU Drive Baltimore MD 21224 USA The Jackson Laboratory 600 Main Street Bar Harbor ME 04609 USA The Solomon H. Snyder Department of Neuroscience Johns Hopkins University School of Medicine 725 N. Wolfe Street Baltimore MD 21205 USA

Dystrobrevin-binding protein 1 （Dtnbp1） is one of the earliest identified schizophrenia susceptibility genes. Reduced expression of DTNBP1 is commonly found in brain areas of schizophrenic patients. Dtnbp1-nuU mutant mice exhibit abnormalities in beha- viors and impairments in neuronal activities. However, how diminished DTNBP1 expression contributes to clinical relevant fea- tures of schizophrenia remains to be illustrated. Here, using a conditional Dtnbp1 knockout mouse line, we identified an in vivo schizophrenia-relevant function of DTNBP1 in pyramidal neurons of the medial prefrontal cortex （mPFC）. We demonstrated that DTNBP1 elimination specifically in pyramidal neurons of the mPFC impaired mouse pre-pu[se inhibition （PPI） behavior and reduced perisomatic GABAergic synapses. We further revealed that loss of DTNBP1 in pyramidal neurons diminished activity- dependent secretion of brain-derived neurotrophic factor （BDNF）. Finally, we showed that chronic BDNF infusion in the mPFC fully rescued both GABAergic synaptic dysfunction and PPI behavioral deficit induced by DTNBP1 elimination from pyramidal neurons. Our findings highlight brain region- and cell type-specific functions of DTNBP1 in the pathogenesis of schizophrenia, and under- score BDNF restoration as a potential therapeutic strategy for schizophrenia.

关键词： schizophrenia GABAergic disinhibition PFC BDNF Dtnbp1

Coupling effects of SiC and TiB_(2) particles on crack inhibition in Al-Zn-Mg-Cu alloy produced by laser powder bed fusion

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Journal of Materials Science & Technology 2023年第33期164卷 37-51页

作者： Ning Li ting Wang Lixia Zhang liang Zhang State Key Laboratory of Advanced Welding and Joining Harbin Institute of Technology at WeihaiWeihai 264209China Shandong Provincial Key Laboratory of Special Welding Technology Harbin Institute of Technology at WeihaiWeihai 264209China Institute of Intelligent Manufacturing Technology Shenzhen PolytechnicShenzhen 518055China

A novel Al-Zn-Mg-Cu alloy free of cracks was produced utilizing laser powder bed fusion(LPBF)and modified with SiC and TiB_(2) *** interdependent effects of SiC and TiB_(2) particles on morphology,microstructure,and crystallographic texture were *** mechanisms behind phase evolution and crack inhibition were *** results show that a nearly dense Al-Zn-Mg-Cu alloy could be obtained when the mass fraction of SiC and TiB2 particles was 4%.TiB_(2) particles remained stable and acted as nucleation agents in the molten *** SiC particles reacted with the Al matrix to form rod-like Al_(4)C_(3),lamellate Al_(4)SiC_(4),and flocculent Si phases,which provided nucleation agents and liquid replenishment for matrix *** columnar grains of the matrix were refined into equiaxed grains,and the average size decreased from 37.15μm to 7.54μ*** preferential growth of grains along the(001)〈001〉direction was suppressed and transformed into a disordered random *** innovative Al-Zn-Mg-Cu alloy demonstrated an ultimate tensile strength of 492±12 MPa and an elongation of 7.2%±0.7%.The microhardness was enhanced,and the microhardness heterogeneity was *** solidification properties were regulated,the temperature interval between solidus and liquidus was narrowed,and the liquidity of the molten pool was *** hot cracking of Al-Zn-Mg-Cu alloy was inhibited due to the interdependent effects of grain refinement by TiB2 particles and sufficient liquid metal replenishment by SiC particles.

关键词： Laser powder bed fusion Solidification cracks Al-Zn-Mg-Cu alloys In-situ reaction Microstructure evolution

A Two-Step GRIN Lens Coating for In Vivo Brain Imaging

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Neuroscience Bulletin 2019年第3期35卷 419-424页

作者： Yupeng Yang Lifeng Zhang Zhenni Wang bo liang Giovanni Barbera Casey Moffitt Yun Li Da-ting Lin Hefei National Laboratory for Physical Sciences at the Microscale School of Life SciencesUniversity of Science and Technology of ChinaHefei 230027China Intramural Research Program National Institute on Drug AbuseNational Institutes of HealthBaltimoreMD 21224USA Department of Zoology and Physiology University of Wyoming College of Arts and SciencesLaramieWY 82071USA

The complex spatial and temporal organization of neural activity in the brain is important for informationprocessing that guides behavior. Hence, revealing the realtime neural dynamics in freely-moving animals is fundamental to elucidating brain function. Miniature fluorescence microscopes have been developed to fulfil this requirement. With the help of GRadient INdex(GRIN)lenses that relay optical images from deep brain regions to the surface, investigators can visualize neural activity during behavioral tasks in freely-moving animals. However, the application of GRIN lenses to deep brain imaging is severely limited by their availability. Here, we describe a protocol for GRIN lens coating that ensures successful long-term intravital imaging with commercially-available GRIN lenses.

关键词： Grin lens Coating Toxic Neurodegeneration

Direct Activation of CFTR Chloride Channel by Natural Compound Theophylline

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Chemical Research in Chinese Universities 2009年第6期25卷 887-890页

作者： LIU Xin GE Hong ZHAO Xue-liang HOU ting-ting SUN Juan-juan YANG Jing-bo HE Cheng-yan YANG Hong China-Japan Union Hospital of Jilin University Changchun 130033 P. R. China School of Life Sciences Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery Liaoning Normal University Dalian 116029 P. R. China School of Chemical Engineering and Technology Tianjin University Tianjin 300072 P. R. China

Theophylline has been widely used in the＇treatment of airway disease but molecular mechanism has not been clearly elucidated. Previous studies have manifested that theophylline increases intracellular cAMP concentra- tion. Because cystic fibrosis transmembrane conductance regulator（CFTR） is a cAMP-dependent Cl- channel that plays key roles in fluid secretion in vivo, we postulated that theophylline activates CFTR channel gating. We found （1） theophylline stimulated CFTR-mediated anion transport in a concentration-dependent manner, and CFTR specific blocker completely reversed the effect; （2） theophylline had no effect on △F508 or G551D mutant CFTR chloride channel activity; （3） theophylline had additive effect with forskolin（FSK） and 3-isobutyl-xanthin（IBMX）, thus a direct binding activation mechanism was suggested. In conclusion, the results may provide a clue to elucidating the molecular mechanism of theophylline activities and theophylline may present a novel lead drug in treating CFTR-related disease.

关键词： Theophylline Cystic fibrosis transmembrane conductance regulator Activator

Molecular Characterization and Functional Analysis of a New Acid Phosphatase Gene(Ha-acp1) from Heterodera avenae

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Journal of Integrative Agriculture 2014年第6期13卷 1303-1310页

作者： LIU Yan-ke HUANG Wen-kun LONG Hai-bo PENG Huan HE Wen-ting PENG De-liang State Key Laboratory for Biology of Plant Diseases and Insect Pests Institute of Plant Protection Chinese Academy of Agricultural Sciences

For sedentary endo-parasitic nematodes, parasitism genes encoding secretory protein expressed in the subventral glands cells always play an important role during the early parasitic process. A new acid phosphatase gene （Ha-acp1） expressed in the subventral glands of the cereal cyst nematode （Heterodera avenae） was cloned and the characteristics of the gene were analyzed. Results showed that the gene had a putative signal peptide for secretion and in situ hybridization showed that the transcripts of Ha-acp1 accumulated speciifcally in the subventral gland cells of H. avenae. Southern blot analysis suggested that Ha-acp1 belonged to a multigene family. RT-PCR analysis indicated that this transcription was strong at the pre-parasitic juveniles. Knocking down Ha-acp1 using RNA interference technology could reduce nematode infectivity by 50%, and suppress the development of cyst. Results indicated that Ha-acp1 could play an important role in destroying the defense system of host plants.

关键词： Heterodera avenae acid phosphatase RNA interference