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Rare Metals 2024年第8期43卷 3702-3712页

作者： Zi-Jie Mu yan-jun gao Wen-Shuai Dong Zong-You Li Qing-Yi Song Han-Jiao Huang Li-Dong Xing Jian-Guo Zhang Wei Wang Qi-Yao Yu State Key Laboratory of Explosion Science and Technology School of Mechatronical EngineeringBeijing Institute of TechnologyBeijing 100081China School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China

The highly reversible insertion/extraction of large-radius K^+into electrode materials remains a tough goal,especially for con version-type ***,we design a current collector-integrated electrode(N-CoSe/CoSe_(2)-C@Cu) as an advanced anode for potassium-ion battery(PIBs).The conductive CoSe/CoSe_(2) heterojunction with rich Se vacancy defects,conductive sp^2 N-doped carbon layer,and the elastic copper foil matrix can greatly accelerate the electron transfer and enhance the structural ***,the well-designed N-CoSe/CoSe_(2)-C@Cu current collector-integrated electrode displays enhanced potassium storage performance with regard to a high capacity(325.1 mAh·g^(-1) at 0.1 A·g^(-1) after 200cycles),an exceptional rate capability(223.5 mAh·g^(-1) at2000 mA·g^(-1)),and an extraordinary long-term cycle stability(a capacity fading of only 0.019% per cycle over1200 cycles at 2000 mA·g^(-1)).Impressively,ex situ scanning electron microscopy(SEM) characterizations prove that the elastic structure of copper foil is merged into the cleverly designed N-CoSe/CoSe_(2)-C@Cu heterostructure,which buffers the deformation of structure and volume and greatly promotes the cycle life during the potassium/depotassium process.

关键词： Potassium-ion battery Integrated collector electrode CoSe CoSe_2 Heterojunction Copper foil matrix N-doped carbon

Impact of travel speed on the microstructure and mechanical properties of adjustable-gap bobbin-tool friction stir welded Al–Mg joints

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International Journal of Minerals,Metallurgy and Materials 2021年第4期28卷 710-717页

作者： Dong Wu Wen-ya Li yan-jun gao jun yang Quan Wen Nektarios Vidakis Achillefs Vairis State Key Laboratory of Solidification Processing Shaanxi Key Laboratory of Friction Travel TechnologiesNorthwestern Polytechnical UniversityXi'an 710072China Capital Aerospace Machinery Company Beijing 100076China Department of Mechanical Engineering Hellenic Mediterranean UniversityHeraklionCrete 71004Greece

The butt welds of 4-mm thick 5A06 aluminum alloy plates were produced by adjustable-gap bobbin-tool friction stir travel with travel speeds of 200, 300, and 400 mm/min in this *** microstructure was studied using optical microscopy and electron backscatter diffraction(EBSD).Tensile tests and microhardness measurements were performed to identify the effect of the travel speed on the joint mechanical *** joints were obtained at 200 mm/min while voids were present at different positions of the joints as the travel speed *** EBSD results show that the grain size, high angle grain boundaries, and density of geometrically necessary dislocations in different regions of the joint vary depending on the recovery and recrystallization *** attention was given to the relationship between the local microstructure and mechanical *** measurements show that the average hardness of the stir zone(SZ) was greater than that of the base material, which was only affected slightly by the travel *** tensile strength of the joint decreased with increasing travel speed and the maximal strength efficiency reached 99%.

关键词： friction stir welding bobbin-tool aluminum alloy microstructure mechanical properties adjustable-gap

Advances of Electrochemical and Electrochemiluminescent Sensors Based on Covalent Organic Frameworks

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Nano-Micro Letters 2024年第2期16卷 395-422页

作者： Yue Cao Ru Wu yan‑yan gao yang Zhou jun‑Jie Zhu Key Laboratory for Organic Electronics and Information Displays(KLOEID)and Institute of Advanced Materials(IAM) Nanjing University of Posts and Telecommunications(NJUPT)Nanjing 210023People’s Republic of China State Key Laboratory of Analytical Chemistry for Life Science School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023People’s Republic of China

Covalent organic frameworks(COFs),a rapidly developing category of crystalline conjugated organic polymers,possess highly ordered structures,large specific surface areas,stable chemical properties,and tunable pore *** the first report of boroxine/boronate ester-linked COFs in 2005,COFs have rapidly gained popularity,showing important application prospects in various fields,such as sensing,catalysis,separation,and energy *** them,COFs-based electrochemical(EC)sensors with upgraded analytical performance are arousing extensive *** this review,therefore,we summarize the basic properties and the general synthesis methods of COFs used in the field of electroanalytical chemistry,with special emphasis on their usages in the fabrication of chemical sensors,ions sensors,immunosensors,and ***,the emerged COFs in the electrochemiluminescence(ECL)realm are thoroughly covered along with their preliminary ***,final conclusions on state-of-the-art COFs are provided in terms of EC and ECL sensors,as well as challenges and prospects for extending and improving the research and applications of COFs in electroanalytical chemistry.

关键词： Covalent organic frameworks Electrochemistry Electrochemiluminescence Sensors

Fractography and morphology of shear bands of a Zr-based bulk metallic glass

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Journal of Iron and Steel Research International 2017年第4期24卷 385-389页

作者： jun Tan jun-yan gao Xue-mei Qin Zheng-rong Fu Dong Li Min Li Xiu-chang Wang Gang Wang School of Materials Science and Engineering Kunming University of Science and Technology Laboratory for Microstructures Shanghai University

Bulk metallic glasses（BMGs）have attracted considerable attention in the last few decades particularly triggered by their potential applications as novel structural and/or functional materials,owing to their superior strength,large elastic strain limit and relatively low Young′s modulus *** to their crystalline ***,a 3Dreconstruction application to the fractography and the morphology of shear bands was reported for a ductile Zr_（56）Co_（28）Al_（16）（at.%）BMG through a Phenom series desktop scanning electron *** results of the 3Dreconstruction and the following contour analysis indicate a typical shear fracture mode for the investigated *** is inferred that the fractography and the morphology of shear bands might be dependent on their composition,structure states,and loading conditions for BMGs.

关键词： Amorphous alloy Fractography Mechanical property Shear band

Resatorvid protects against hypoxic-ischemic brain damage in neonatal rats

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Neural Regeneration Research 2020年第7期15卷 1316-1325页

作者： Li-jun Jiang Zhen-Xing Xu Ming-Fu Wu Gai-Qin Dong Li-Li Zhang jun-yan gao Chen-Xi Feng Xing Feng Department of Neonatology Children's Hospital of Soochow UniversitySuzhouJiangsu ProvinceChina Department of Neonatology Affiliated Hospital of Yangzhou UniversityYangzhouJiangsu ProvinceChina

Secondary brain damage caused by hyperactivation of autophagy and inflammatory responses in neurons plays an important role in hypoxic-ischemic brain damage(HIBD).Although previous studies have implicated Toll-like receptor 4(TLR4)and nuclear factor kappa-B(NF-κB)in the neuroinflammatory response elicited by brain injury,the role and mechanisms of the TLR4-mediated autophagy signaling pathway in neonatal HIBD are still *** hypothesized that this pathway can regulate brain damage by modulating neuron autophagy and neuroinflammation in neonatal rats with ***,we established a neonatal HIBD rat model using the Rice-Vannucci method,and injected 0.75,1.5,or 3 mg/kg of the TLR4 inhibitor resatorvid(TAK-242)30 minutes after hypoxic *** results indicate that administering TAK-242 to neonatal rats after HIBD could significantly reduce the infarct volume and the extent of cerebral edema,alleviate neuronal damage and neurobehavioral impairment,and decrease the expression levels of TLR4,phospho-NF-κB p65,Beclin-1,microtubule-associated protein l light chain 3,tumor necrosis factor-α,and interleukin-1βin the ***,TAK-242 appears to exert a neuroprotective effect after HIBD by inhibiting activation of autophagy and the release of inflammatory cytokines via inhibition of the TLR4/NF-κB signaling *** study was approved by the Laboratory Animal Ethics Committee of Affiliated Hospital of yangzhou University,China(approval No.20180114-15)on January 14,2018.

关键词： autophagy hypoxic-ischemic brain damage neonatal hypoxic-ischemic brain damage neuroinflammation nuclear factor kappa-B resatorvid TAK-242 Toll-like receptor 4

Improving S/N ratio for pre-stack seismic data from western China

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Applied Geophysics 2007年第3期4卷 207-213页

作者： Guo Ping Zhang Wenpo gao yan Zhao jun gao Shumei Exploration ＆ Development Research Institute Liaohe Oilfield PetroChina Panjin 124010 China

The seismic data from western China is very noisy. Two main reasons are static corrections and low S/N ratio problems. By seismic data processing and study these problems have been effectively solved by iterating the static corrections and improving the S/N ratio for pre-stack seismic data. Suppression and elimination of various other distortions has been implemented as well. Due to the fact that the S/N ratio is improved, the resolution of the seismic data is also improved.

关键词： Static correction low S/N ratio resolution

Thermal and mechanical behavior of casting copper alloy wheel during wheel and belt continuous casting process

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China Foundry 2024年第1期21卷 82-90页

作者： Kun gao yan Peng School of Mechanical Engineering Yanshan UniversityQinhuangdao 066004HebeiChina

To investigate the thermal and mechanical behavior of casting wheel,a two-dimensional thermoelastic-plastic finite element model was used to predict the temperature,stress and distortion distribution of the casting wheel during the wheel and belt continuous casting *** effects of grinding thickness and casting speed on the thermal and mechanical behaviors of the center of the hot face of the casting wheel were discussed in *** each rotation,the casting wheel passes through four different spray *** results show that the temperature distribution of the casting wheel in different spray zones is similar,the temperature of the hot face is the highest and the temperature reaches the peak in the spray zoneⅢ.The stress and distortion depend on the temperature distribution,and the maximum stress and distortion of the hot face are 358.2 MPa and 1.82 mm,*** temperature at the center of the hot face decreases with increasing grinding thickness and increases with increasing casting speed.

关键词： casting wheel finite element model grinding thickness casting speed hot face spray zones

Numerical simulation of fluid flow and free surface fluctuations during wheel and belt casting process

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Journal of Iron and Steel Research International 2024年第5期31卷 1117-1126页

作者： Kun gao yan Peng National Engineering Research Center for Equipment and Technology of Cold Strip Rolling Yanshan UniversityQinhuangdao066004HebeiChina

The unstable fluid flow and severe free surface fluctuations in the wheel and belt caster can affect the quality of the cast *** lower level height tends to entrap inclusions in the molten *** the other hand,the higher level height makes the production process more dangerous due to the overflow of high temperature fluid from the mold.A computational model of the molten metal pouring process was *** transient fluid flow and free surface fluctuations behavior were calculated using the three-dimensional large eddy simulation model and the volume of fluid *** results show that the flow velocity of the main jet gradually decreases under the influence of the low kinetic energy fluid in the *** is an obvious oscillation in the tail of the jet,while the flow field is asymmetric in *** jet is closer to the inside radius side due to the Coanda effect,and there is a recirculation zone on the inside radius and the outside radius respectively,according to the 10 s time-averaged *** with the industrial observation and simulation results,the shape of the free surface is a wave that varies with *** addition,the free surface height is lowest and the flow velocity is highest in the region near the jet.

关键词： Fluid flow Free surface Wheel and belt caster Large eddy simulation Volume of fluid method

A review on recent progress of thermionic cathode

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Tungsten 2020年第3期2卷 289-300页

作者： jun‑yan gao Yun‑Fei yang Xiao‑Ke Zhang Shi‑Lei Li Peng Hu Jin‑Shu Wang Key Laboratory of Advanced Functional Materials Education Ministry of ChinaFaculty of Materials and ManufacturingBeijing University of TechnologyBeijing 100124China

As the performance of vacuum electron devices is essentially governed by the properties of their cathodes,developing efficient and durable thermionic cathode is necessary and highly desired to meet the boosting requirements of vacuum electron *** review summarized the progress made in the past decades with a detailed discussion on the occurred various thermionic cathodes and their features,and the understandings of the correlation between the emission properties and the composition,where structure and synthesis method are well ***,dispenser cathodes with novel structures and emission mechanism are highlighted to indicate the recent achievement in this area of research,and Sc-cathode is considered as a promising candidate for the next-generation vacuum electron devices due to the greatly improved ***,challenges still exist to meet the ever-growing demands of thermionic cathode with collaborative requirement of high performance,easy fabrication and inadequate reproducibility.

关键词： Thermionic cathodes Performance Emission mechanism Ion bombardment Work function Tungsten

Reliability of DC-link capacitor in pulsed power supply for accelerator magnet

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Nuclear Science and Techniques 2024年第9期35卷 28-40页

作者： Jie Wang Da-Qing gao Wan-Zeng Shen Hong-Bin yan Li-jun Mao Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China

Capacitors are widely used in pulsed magnet power supplies to reduce ripple voltage,store energy,and decrease power *** this study,DC-link capacitors in pulsed power supplies were *** deriving an analytical method for the capacitor current on the H-bridge topology side,the root-mean-square value of the capacitor current was calculated,which helps in selecting the DC-link *** proposed method solves this problem quickly and with high *** current reconstruction of the DC-link capacitor is proposed to avoid structural damage in the capacitor’s current measurement,and the capacitor’s hotspot temperature and temperature rise are calculated using the FFT *** test results showed that the error between the calculated and measured temperature increases was within 1.5℃.Finally,the lifetime of DC-link capacitors was predicted based on Monte Carlo *** proposed method can evaluate the reliability of DC-link capacitors in a non-isolated switching pulsed power supply for accelerators and is also applicable to film capacitors.

关键词： Aluminum electrolytic capacitor DC-link current DC–DC power converter Hotspot temperature