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Probing the electric double layer structure at nitrogen-doped graphite electrodes by constant-potential molecular dynamics simulations

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Journal of Energy Chemistry 2024年第6期93卷 299-305,I0008页

作者： Legeng Yu Nan Yao Yu-Chen Gao Zhong-heng fu Bo Jiang Ruiping Li Cheng Tang Xiang Chen Tsinghua Center for Green Chemical Engineering Electrification(CCEE) Department of Chemical EngineeringTsinghua UniversityBeijing 100084China Beijing Advanced Innovation Center for Materials Genome Engineering Institute for Advanced Materials and TechnologyUniversity of Science and Technology BeijingBeijing 100083China National Materials Corrosion and Protection Data Center University of Science and Technology BeijingBeijing 100083China Ordos Carbon Neutral Research and Application Co. Ltd.Ordos 017010Inner Mongoli1China Institute for Carbon Neutrality Tsinghua UniversityBeijing 100084China Center for Next-Generation Energy Materials and School of Chemical Engineering Sungkyunkwan University2066 Seobu-roJangan-guSuwon-siGyeonggi-do 16419Republic of Korea

Electric double layer(EDL)is a critical topic in electrochemistry and largely determines the working performance of lithium ***,atomic insights into the EDL structures on heteroatom-modified graphite anodes and EDL evolution with electrode potential are very ***,a constant-potential molecular dynamics(CPMD)method is proposed to probe the EDL structure under working conditions,taking N-doped graphite electrodes and carbonate electrolytes as an *** interface model was developed,incorporating the electrode potential and atom *** a result,an insightful atomic scenario for the EDL structure under varied electrode potentials has been established,which unveils the important role of doping sites in regulating both the EDL structures and the following electrochemical reactions at the atomic ***,the negatively charged N atoms repel the anions and adsorb Li~+at high and low potentials,*** preferential adsorption suggests that Ndoped graphite can promote Li~+desolvation and regulate the location of Li~+*** CPMD method not only unveils the mysterious function of N-doping from the viewpoint of EDL at the atomic level but also applies to probe the interfacial structure on other complicated electrodes.

关键词： Lithium batteries Graphite N-doping Electric double layer Molecular dynamics Constant potential method Electrode potential

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EBSD analysis of grain boundary evolution and dynamic recrystallization of Inconel 625 superalloy at various hot spinning feed rates

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Progress in Natural Science:Materials International 2024年第1期34卷 56-65页

作者： Zhanjie Jing Jiangkun Fan Xudong Liu Yuelin Song Zixiao Wang Kai Cao Yuetan Chen heng fu Jianing Zhang Jinshan Li State Key Laboratory of Solidification Processing Northwestern Polytechnical University Chongqing Innovation Center Northwestern Polytechnical University National&Local Joint Engineering Research Center for Precision Thermoforming Technology of Advanced Metal Materials

Hot spinning can make the material withstand shear stress, so that the shape of the material has a great change,which is one of the main processing methods of nickel-based alloy plate members. Inconel 625 alloy, which has excellent high temperature mechanical properties and can be used as the main candidate material for aerospace applications, needs further study on its hot spinning deformation behavior and deformation mechanism. In this paper, the effect of feed rate on the microstructure evolution of Inconel 625 superalloy was studied by the electron backscattered diffraction technology. The microstructure with necklace-like structures composed of dynamic recrystallization(DRX) grains was observed after hot spinning. It was found that at the low feed rate, the promotion of DRX degree and grain refinement happened, where the grain size reached the trough of 10.99 μm under a feed rate of 300 mm/min. However, with the further feed rate rising, the degree of DRX was suppressed to a certain extent and grain size increased to 14.26 μm. On balance, the feed rate of 300 mm/min was the most efficient condition for grain refinement. Besides, it was revealed that both discontinuous dynamic recrystallization(DDRX) and continuous dynamic recrystallization(CDRX) occurred during hot spinning. DDRX includes the initial grain boundary nucleation by bulging and the annealing twin boundary assisted nucleation, while the CDRX mechanism is related to the continuous subgrain rotation within the deformed grain. DDRX is the main DRX mechanism.

关键词： Inconel 625 superalloy Hot spinning Grain boundary evolution DRX mechanism

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Electronic-scale assessment of high-temperature oxidation mechanisms in a novel Fe-based alloy

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Journal of Iron and Steel Research International 2024年第4期31卷 982-997页

作者： Wei-di Luo Ting-ping Hou Xuan Liang Dong Zhang heng-fu Lin Yu Li Tian-liang Zhao Cheng-yang Hu Serhii Yershov Kai-ming Wu The State Key Laboratory of Refractories and Metallurgy.Wuhan University of Science and Technology.Wuhan 430081 HubeiChina Hubei Province Key Laboratory of Systems Science in Meallurgial Process Wuhan University of Science and Technology.Wuhan 430081.Hubei.China International Research Institute for Steel Technology Wuhan University of Science and Technology.Wuhan 430081.HubeiChina Collaborative Innovation Center for Advanced Steels w uhan University of Science and Technology.Wuhan 430081.HuleiChina

The development of alloys with high antioxidation performance is limited by the ambiguous details of the oxidation ***,based on the structures of internal oxides detected by high-resolution transmission electron microscopy,a hybrid method combining first-principles calculation,climb image nudged elastic band method and quasi-harmonic Debye model has been implemented to explain the oxidation mechanism with an emphasis on the origin of delamination and *** results showed that the delamination of oxides corresponds to the acceleration of diffusion of Cr element caused by lamellar *** reduction in the cracking occurrence at high temperature mainly results from the smaller bulk modulus of ***,the stronger chemical bonds promoted by lamellar structures also correspond to the higher crackingresistance.

关键词： Oxidation Crystal structure Diffusion Cracking-First-principles calculation

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Bending Failure Mode and Prediction Method of the Compressive Strain Capacity of A Submarine Pipeline with Dent Defects

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China Ocean Engineering 2024年第4期38卷 636-647页

作者： HOU fu-heng JIA Lu-sheng CHEN Yan-fei ZHANG Qi ZHONG Rong-feng WANG Chun-sha School of Mechanical and Transportation Engineering China University of PetroleumBeijingBeijing 102249China CNOOC Research Institute Ltd.Beijing 100028 China

A dent is a common type of defects for submarine *** submarine pipelines,high hydrostatic pressure and internal pressure are the main *** pipelines bend due to complex subsea conditions,the compression strain capacity may be *** into the local buckling failure and accurate prediction of the compressive strain capacity are important.A finite element model of a pipeline with a dent is *** buckling failure under a bending moment is investigated,and the compressive strain capacity is *** effects of different parameters on pipeline local buckling are *** results show that the dent depth,external pressure and internal pressure lead to different local buckling failure modes of the pipeline.A higher internal pressure indicates a larger compressive strain capacity,and the opposite is true for external *** the ratio of external pressure to collapse pressure of intact pipeline is greater than 0.1,the deeper the dent,the greater the compressive strain capacity of the *** as the ratio is less than 0.1,the opposite is *** the basis of these results,a regression equation for predicting the compressive strain capacity of a dented submarine pipeline is proposed,which can be referred to during the integrity assessment of a submarine pipeline.

关键词： submarine pipeline dent defect bending load local buckling compressive strain capacity

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基于BP神经网络的高密度电法在水库清淤扩容坝后排泥区围堰探测中的应用

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水电能源科学 2024年第5期42卷 174-178页

作者：张喆马福恒霍吉祥南京水利科学研究院江苏南京210029 河海大学水利水电学院江苏南京210098 水利部大坝安全管理中心江苏南京210029

高密度电法具有采集数据量大、效率高、反演信息丰富等特点,在水库大坝病险隐患探测领域得到广泛应用。目前,使用基于最小二乘法的反演容易受地电数据局部极值影响,使得探测到的病害位置和规模不准确。对此,通过建立不同参数值、形态大... 详细信息

高密度电法具有采集数据量大、效率高、反演信息丰富等特点,在水库大坝病险隐患探测领域得到广泛应用。目前,使用基于最小二乘法的反演容易受地电数据局部极值影响,使得探测到的病害位置和规模不准确。对此,通过建立不同参数值、形态大小及位置分布的异常体正演模型,将模型数据作为训练样本,以此构建基于BP神经网络的高密度电法反演模型;将训练完成的反演模型应用于水库清淤扩容坝后排泥区围堰的高密度电法探测结果分析中。结果表明,所提方法能够减小局部电流极值引起的屏蔽作用,缩小隐患排查范围,提高了高密度电法受高阻屏蔽影响下分辨隐患的准确性和反演精度,可对物探资料作出更为精确的解释。

关键词：高密度电法 BP神经网络反演模型清淤围堰隐患探测

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基于加权空间划分的高效全局K-means聚类算法

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吉林大学学报（工学版） 2024年第5期54卷 1393-1400页

作者：曲福恒潘曰涛杨勇胡雅婷宋剑飞魏成宇长春理工大学计算机科学技术学院长春130022 吉林电子信息职业技术学院吉林省吉林市132021 吉林农业大学信息技术学院长春130118

针对全局K-means聚类算法穷举样本点导致计算量大的问题,提出一种基于加权空间划分的高效全局K-means聚类算法。算法首先对样本空间进行网格划分,然后提出密度准则与距离准则对网格进行过滤,保留密度较大且相互距离较远的网格作为候选... 详细信息

针对全局K-means聚类算法穷举样本点导致计算量大的问题,提出一种基于加权空间划分的高效全局K-means聚类算法。算法首先对样本空间进行网格划分,然后提出密度准则与距离准则对网格进行过滤,保留密度较大且相互距离较远的网格作为候选中心网格。为避免全局K-means算法只在样本集中选取候选中心的局限性,提出权重准则和中心迭代策略扩充候选中心,增加候选中心多样性。最后,通过增量聚类方式遍历候选中心得到最终的聚类结果。在UCI数据集上的实验结果表明:与全局K-means算法相比,新算法在保证聚类精度的前提下,计算效率平均提高了89.39%~95.79%。与K-means++、IK-+和近期提出的CD算法相比,新算法精度更高,并且克服了因随机初始化导致的聚类结果不稳定问题。

关键词：人工智能 K-means算法聚类中心网格划分权重增量式聚类

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加巴喷丁减轻骨折模型大鼠焦虑情绪及海马神经炎症的作用机制研究

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安徽医药 2024年第5期28卷 889-893页

作者：徐礼玲付恒曾思自贡市精神卫生中心四川自贡643020 四川省医学科学院四川成都610000

目的探析加巴喷丁对骨折模型大鼠焦虑情绪、海马神经炎症、人核因子κB(NF-κB)/肿瘤坏死因子α(TNF-α)信号通路的影响。方法自2022年1―6月,选择健康雄性无特定病原体(SPF)SD大鼠48只,采用随机数字表法分为假手术组、模型组、治疗组... 详细信息

目的探析加巴喷丁对骨折模型大鼠焦虑情绪、海马神经炎症、人核因子κB(NF-κB)/肿瘤坏死因子α(TNF-α)信号通路的影响。方法自2022年1―6月,选择健康雄性无特定病原体(SPF)SD大鼠48只,采用随机数字表法分为假手术组、模型组、治疗组。假手术组正常饲养,未做任何处理,其余两组大鼠均进行骨折造模。其中治疗组给予加巴喷丁治疗,模型组给予等量生理盐水干预,连续给药12 d。采用高架十字迷宫实验评估大鼠焦虑情绪;采用酶联免疫吸附(ELISA)检测白细胞介素-4(IL-4)、白细胞介素-6(IL-6)、白细胞介素-1β(IL-1β)、超氧化物歧化酶(SOD)、丙二醛(MDA),采用比色法检测谷胱甘肽过氧化物酶(GSH-Px)。采用苏木素伊红(HE)染色评估海马组织病理形态特征;采用蛋白质印迹法检测TNF-α、NF-κB蛋白表达量。结果假手术组、治疗组、模型组总穿臂次数(TE)、进入比例(OE)、停留时间比例(OT)比较,假手术组大鼠TE[(12.31±2.59)次比(10.29±2.37)次、(7.25±2.16)次]、OE[(40.25±5.41)%比(37.02±5.13)%、(32.77±5.43)%]、OT[(23.67±4.22)%比(21.94±5.31)%、(16.47±2.35)%]均高于治疗组、模型组大鼠,治疗组大鼠TE、OE、OT均高于模型组(P<0.05)。假手术组大鼠IL-4[(41.23±5.37)ng/L比(50.23±6.78)ng/L、(59.44±6.92)ng/L]、IL-6[(101.45±12.36)ng/L比(114.32±12.74)ng/L、(135.49±16.78)ng/L]、IL-1β[(87.64±8.74)ng/L比(101.23±10.45)ng/L、(110.34±10.25)ng/L]均低于治疗组、模型组大鼠,治疗组大鼠IL-4、IL-6、IL-1β均低于模型组(P<0.05)。假手术组大鼠GSH-Px、SOD均高于治疗组、模型组大鼠,MDA低于两组;且治疗组大鼠GSH-Px、SOD均高于模型组,MDA低于该组(P<0.05)。假手术组大鼠NF-κB、TNF-α蛋白表达均低于治疗组、模型组大鼠,治疗组大鼠NF-κB、TNF-α蛋白表达均低于模型组(P<0.05)。结论骨折导致大鼠焦虑情绪增加,而加巴喷丁可以有效削弱骨折大鼠的焦虑情绪,可能与加巴喷丁减弱海马炎症反应有关,从而增强NF-κB/TNF-α信号通路对海马神经的保护作用。

关键词：加巴喷丁大鼠骨折焦虑海马神经炎症

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Ti、Zr和Hf元素协同优化Nb-Si基合金显微组织、相组成和室温断裂韧性

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Transactions of Nonferrous Metals Society of China 2024年第1期34卷 194-202页

作者：王琪赵天宇陈瑞润王晓伟徐琴王墅傅恒志哈尔滨工业大学材料科学与工程学院金属精密热加工国家重点实验室哈尔滨150001 河南工业大学机电工程学院郑州450001

采用真空电弧熔炼制备Nb-16Si-xTi-yZr-zHf (x=18, 22;y=0, 4;z=0, 4;摩尔分数,%)合金并研究Ti、Zr与Hf元素对Nb-Si合金物相组成、显微组织、断裂韧性以及裂纹扩展行为的影响。结果表明:单独添加4%Zr元素能促进(Nb,X)3Si向Nb固溶体(Nbs... 详细信息

采用真空电弧熔炼制备Nb-16Si-xTi-yZr-zHf (x=18, 22;y=0, 4;z=0, 4;摩尔分数,%)合金并研究Ti、Zr与Hf元素对Nb-Si合金物相组成、显微组织、断裂韧性以及裂纹扩展行为的影响。结果表明:单独添加4%Zr元素能促进(Nb,X)3Si向Nb固溶体(Nbss)/γ-(Nb,X)5Si3共析反应的发生;同时添加Ti、Zr、Hf元素能进一步促进共析反应的发生。裂纹倾向于在(Nb,X)3Si中扩展,当裂纹途径Nb固溶体时会发生偏转。细密的Nbss/γ-(Nb,X)5Si3共晶组织以及层状Nbss/γ-(Nb,X)5Si3共晶组织可以使裂纹产生桥接与分支,阻碍裂纹的扩展。Nb-16Si-22Ti-4Zr-4Hf的合金化元素含量最高,因此,其室温断裂韧性最好(11.62 MPa·m1/2),相较于Nb-16Si-18Ti提高87.7%,性能的提升主要归因于存在层状共晶组织。

关键词： Nb-Si合金合金化断裂韧性裂纹扩展

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Phase selection and solidification path transition of Ti-48Al-xNb alloys with different cooling rates

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Rare Metals 2023年第1期42卷 288-295页

作者： Tan He Rui Hu Jie-Ren Yang heng-Zhi fu The State Key Laboratory of Solidification Processing School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an710072China

Ti-48Al-xNb alloys were solidified by containerless electromagnetic levitation with quenching system of the conical copper *** influence of cooling rates on phase selection of T1-48Al-xNb alloys was *** near-equilibrium solidification condition,the dendrite βphase is observed as the leading *** other metastable phase(e.g.,α phase) is *** contrast,in rapid solidification condition,the metastable α phase is observed in as-quenched Ti-48Al-2Nb ***,the metastable α phase is replaced by the primary β phase with Nb addition *** Ti-48Al-(x=4,6,8)Nb alloys,increasing cooling rate results in a solidification path *** peritectic reaction(L+β→α) is therefore significantly *** relationships between primary dendrite arm spacing(λ_(1)) and cooling rate(τ) can be described.

关键词： TiAl alloy Cooling rate Microstructure Phase selection

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Growth characteristics of directionally solidified Al_2O_3/YAG/ZrO_2 ternary hypereutectic in situ composites under ultra-high temperature gradient

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International Journal of Minerals,Metallurgy and Materials 2011年第1期18卷 121-125页

作者： Hai-jun Su Jun Zhang Lin Liu heng-zhi fu State Key Laboratory of Solidification Processing Northwestern Polytechnical University Xi＇an 710072 China

Oxide eutectic ceramic in situ composites have attracted significant interest in the application of high-temperature structural materials because of their excellent high-temperature strength,oxidation and creep resistance,as well as outstanding microstructural *** directionally solidified ternary Al2O3/YAG/ZrO2 hypereutectic in situ composite was successfully prepared by a laser zone remelting method,aiming to investigate the growth characteristic under ultra-high temperature *** microstructures and phase composition of the as-solidified hypereutectic were characterized by using scanning electron microscopy（SEM）,energy dispersive spectroscopy（EDS）,and X-ray diffraction（XRD）.The results show that the composite presents a typical hypereutectic lamellar microstructure consisting of fine Al2O3 and YAG phases,and the enriched ZrO2 phases with smaller sizes are randomly distributed at the Al2O3/YAG interface and in Al2O3 *** power and scanning rate strongly affect the sample quality and microstructure ***,coarse colony microstructures were also observed,and their formation and the effect of temperature gradient on the microstructure were discussed.

关键词： eutectics ceramic materials microstructure thermal gradients remelting solidification

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