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Damage analysis caused by ^(60)Co ions in functionally graded materials
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作者 Zübeyde Özkan Ugur Gökmen Sema Bilge Ocak 《Defence Technology(防务技术)》 2025年第2期248-256,共9页
Functionally graded composite/hybrid materials(FGCM/FGHCM)were produced by adding B_(4)C,TiO_(2),and B_(4)C+TiO_(2)ceramic materials at various ratios(0-50%)into the AA6082 matrix.The analysis of the damage caused by^... Functionally graded composite/hybrid materials(FGCM/FGHCM)were produced by adding B_(4)C,TiO_(2),and B_(4)C+TiO_(2)ceramic materials at various ratios(0-50%)into the AA6082 matrix.The analysis of the damage caused by^(60) ions'(1.173-1.1332 MeV)on the material was examined using the SRIM/TRIM Monte Carlo simulation software.In the simulation,the following data regarding the atoms of the target materials were obtained:ion distribution,target ionization,total displacements,surface binding energy,lattice binding energy,and displacement energy.Among the studied four materials,the one with the highest ion range value was found to be AA6082 with 8550A.TiO_(2)was found to be the reinforcement material that reduced the ion range the most in the material.Due to its high binding energy,B_(4)C reinforced AA6082+(0-50%)B_(4)C FGCM was found to have the least vacancy with 4782/ion. 展开更多
关键词 SRIM/TRIM Damage analysis AA6082 ^(60)Co ion
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基于混杂模型预测控制的分布式驱动电动汽车AFS/DYC集成控制 被引量:1
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作者 郑字琛 王姝 +1 位作者 赵轩 李兆柯 《汽车工程》 北大核心 2025年第3期470-480,469,共12页
为提高分布式驱动电动汽车在不同附着路面高速行驶的操纵稳定性,提出一种基于混杂模型预测控制的AFS/DYC集成控制策略。首先基于系统辨识方法构建轮胎分段仿射模型,结合车辆动力学模型以及命题逻辑与线性不等式的转换关系,构建车辆系统... 为提高分布式驱动电动汽车在不同附着路面高速行驶的操纵稳定性,提出一种基于混杂模型预测控制的AFS/DYC集成控制策略。首先基于系统辨识方法构建轮胎分段仿射模型,结合车辆动力学模型以及命题逻辑与线性不等式的转换关系,构建车辆系统混合逻辑动态模型。然后设计基于混杂模型预测控制的AFS/DYC集成控制策略,采用混合整数二次规划方法追踪目标参考值决策附加横摆力矩与附加转向角,并以轮胎负荷率最小为目标构建车轮驱动转矩优化分配控制策略。最后,基于CarSim-Simulink联合仿真平台进行驾驶人在环操纵稳定性测试试验。测试结果表明:相较于传统模型预测控制,所设计的混杂模型预测控制策略在高速双移线工况下横摆角速度与质心侧偏角均方根误差分别下降了31.61%与19.51%,四轮峰值平均转矩幅值降低24.27%。 展开更多
关键词 分布式驱动电动汽车 操纵稳定性 集成控制 分段仿射模型 混杂系统
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Ti6Al4V合金表面渗钽层的制备及力学性能
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作者 付光远 林乃明 +4 位作者 李小凯 Meisam Nouri 曾群锋 LI Dongyang 吴玉程 《太原理工大学学报》 北大核心 2025年第4期706-715,共10页
【目的】为提高Ti6Al4V(TC4)合金的表面性能,借助双层辉光等离子表面合金化技术在其表面制备渗钽层,结合Taguchi实验设计研究了工艺参数对渗钽层表面硬度的影响。【方法】借助光学显微镜、X射线衍射仪、扫描电子显微镜及能量谱仪分析渗... 【目的】为提高Ti6Al4V(TC4)合金的表面性能,借助双层辉光等离子表面合金化技术在其表面制备渗钽层,结合Taguchi实验设计研究了工艺参数对渗钽层表面硬度的影响。【方法】借助光学显微镜、X射线衍射仪、扫描电子显微镜及能量谱仪分析渗钽层的特征。使用显微硬度计和纳米压入仪对比研究TC4基体和渗钽层的力学性能。【结果】结果表明:得到优化的工艺参数组合:温度750℃,源阴极压差350 V,保温时间2 h。优化工艺参数的渗钽层连续、均匀、致密,主要由α-Ta和金属间化合物相构成。渗钽层表面硬度比TC4基体提高了约3.2倍,其H/E和H^(3)/E^(2)值分别是TC4基体的2.1倍和15.0倍。双辉等离子表面合金化渗钽处理显著提高了TC4合金的抵抗局部塑性变形能力。 展开更多
关键词 钛合金 双辉等离子表面合金化 力学性能
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发动机燃油泵空化研究进展
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作者 王永康 陈文刚 +2 位作者 王海军 Dongyang LI 王文 《流体机械》 北大核心 2025年第1期76-84,96,共10页
发动机燃油泵的空化对发动机的使用安全和寿命有着重大影响,通过综合国内外对于发动机燃油泵内空化研究成果的概述,系统地归纳总结了空化在燃油泵中形成的原因、影响因素、研究方法以及发展现状等,指出了影响流体机械内空化产生与发展... 发动机燃油泵的空化对发动机的使用安全和寿命有着重大影响,通过综合国内外对于发动机燃油泵内空化研究成果的概述,系统地归纳总结了空化在燃油泵中形成的原因、影响因素、研究方法以及发展现状等,指出了影响流体机械内空化产生与发展的两大因素,即发生空化作用物体的几何形态以及物理因素(如压力、温度等)。对研究与观察燃油泵空化现象的方法进行了整理与划分,并给出了研究流体机械内空化现象以及降低空化影响的新方案,为发动机燃油泵的优化提供了方向。 展开更多
关键词 空化 燃油泵 影响因素 流体机械
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Hydrophilic-substrate-assisted Fabrication of Flexible and Transparent Au NTOH@PDMS Film for SERS In-situ Detection of Crystal Violet 被引量:1
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作者 ZHANG Xin-tong LIU Hong-yu +2 位作者 DONG Ming-yuan WANG Li LIN Xiang 《分析测试学报》 北大核心 2025年第3期411-419,共9页
This article presented a facile fabrication process for polydimethylsiloxane(PDMS)composite gold nanotris⁃octahedra(Au NTOH)for a flexible SERS sensor with high sensitivity.Specifically,Au NTOH with excellent SERS beh... This article presented a facile fabrication process for polydimethylsiloxane(PDMS)composite gold nanotris⁃octahedra(Au NTOH)for a flexible SERS sensor with high sensitivity.Specifically,Au NTOH with excellent SERS behaviors was synthesized using a seed-mediated growth method and the dimensions of the Au NTOH was easily tuned.In addition,the influence of size on the SERS performance of their monolayers was systematically investigated,and the Au NTOH with the size of 61 nm possessed the best SERS performance.Importantly,a hydrophilic-substrateassisted interfacial self-assembled monolayer transfer technique was proposed to transfer Au NTOH onto PDMS films,resulting in forming flexible and transparent Au NTOH@PDMS substrates.Furthermore,the excellent signal homoge⁃neity of this substrate was demonstrated and the sensitivity was verified by a measurement of crystal violet(CV)as low as 1×10^(-8) mol/L.As a result,this SERS sensor is progressing for applying in the identification of trace contaminants in broad fields. 展开更多
关键词 Au NTOH PDMS interfacial self-assembly SERS crystal violet
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Synthesis,structures,and properties of metal-organic frameworks based on bipyridyl ligands and isophthalic acid 被引量:1
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作者 HOU Jimin LI Mengyang +4 位作者 GONG Chunhua ZHANG Shaozhuang ZHAN Caihong XU Hao XIE Jingli 《无机化学学报》 北大核心 2025年第3期549-560,共12页
(2E,6E)-4-methyl-2,6-bis(pyridin-3-ylmethylene)cyclohexan-1-one(L_(1))and 4-methyl-2,6-bis[(E)-4-(pyridin-4-yl)benzylidene]cyclohexan-1-one(L_(2))were synthesized and combined with isophthalic acid(H_(2)IP),then under... (2E,6E)-4-methyl-2,6-bis(pyridin-3-ylmethylene)cyclohexan-1-one(L_(1))and 4-methyl-2,6-bis[(E)-4-(pyridin-4-yl)benzylidene]cyclohexan-1-one(L_(2))were synthesized and combined with isophthalic acid(H_(2)IP),then under solvothermal conditions,to react with transition metals achieving four novel metal-organic frameworks(MOFs):[Zn(IP)(L_(1))]_(n)(1),{[Cd(IP)(L_(1))]·H_(2)O}_(n)(2),{[Co(IP)(L_(1))]·H_(2)O}_(n)(3),and[Zn(IP)(L_(2))(H_(2)O)]_(n)(4).MOFs 1-4 have been characterized by single-crystal X-ray diffraction,powder X-ray diffraction,thermogravimetry,and elemental analysis.Single-crystal X-ray diffraction shows that MOF 1 crystallizes in the monoclinic crystal system with space group P2_(1)/n,and MOFs 2-4 belong to the triclinic system with the P1 space group.1-3 are 2D sheet structures,2 and 3 have similar structural characters,whereas 4 is a 1D chain structure.Furthermore,1-3 exhibited certain photocatalytic capability in the degradation of rhodamine B(Rh B)and pararosaniline hydrochloride(PH).4could be used as a heterogeneous catalyst for the Knoevenagel reaction starting with benzaldehyde derivative and malononitrile.4 could promote the reaction to achieve corresponding products in moderate yields within 3 h.Moreover,the catalyst exhibited recyclability for up to three cycles without significantly dropping its activity.A mechanism for MOF 4 catalyzed Knoevenagel condensation reaction of aromatic aldehyde and malononitrile has been initially proposed.CCDC:2356488,1;2356497,2;2356499,3;2356498,4. 展开更多
关键词 bipyridyl ligands metal⁃organic frameworks photocatalytic degradation Knoevenagel condensation
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Structure variation of cadmium naphthalene⁃diphosphonates with the changing rigidity of N⁃donor auxiliary ligands
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作者 XU Yan LI Suzhi +3 位作者 LI Yan FENG Lushun SUN Wentao LI Xinxing 《无机化学学报》 北大核心 2025年第2期395-406,共12页
Five cadmium naphthalene-diphosphonates,formulated as[Cd_(1.5)(1,4-ndpaH_(2))2(4,4'-bpyH)(4,4'-bpy)0.5(H_(2)O)_(2)]2(1),[Cd(1,4-ndpaH_(2))(1,4-bib)0.5(H_(2)O)](2),[Cd(1,4-ndpaH3)2(1,2-dpe)(H_(2)O)]·(1,2-d... Five cadmium naphthalene-diphosphonates,formulated as[Cd_(1.5)(1,4-ndpaH_(2))2(4,4'-bpyH)(4,4'-bpy)0.5(H_(2)O)_(2)]2(1),[Cd(1,4-ndpaH_(2))(1,4-bib)0.5(H_(2)O)](2),[Cd(1,4-ndpaH3)2(1,2-dpe)(H_(2)O)]·(1,2-dpe)·7H_(2)O(3),(1,2-bixH)[Cd3(1,4-ndpaH)(1,4-ndpaH_(2))2(H_(2)O)_(2)](4),and[Cd(1,4-ndpaH_(2))(H_(2)O)]·H_(2)O(5),have been synthesized from the selfassembly reactions of 1,4-naphthalenediphosphonic acid(1,4-ndpaH4)with Cd(NO3)2·4H_(2)O by introducing auxiliary ligands with variation of rigidity,such as 4,4'-bipyridine(4,4'-bpy),1,4-bis(1-imidazolyl)benzene(1,4-bib),1,2-di(4-pyridyl)ethylene(1,2-dpe),1,3-di(4-pyridyl)propane(1,3-dpp),and bis(imidazol-1-ylmethyl)benzene(1,2-bix),respectively.Structure resolution by single-crystal X-ray diffraction reveals that compound 1 possesses a layered framework,in which the{Cd3(PO2)2}trimers made up of corner-sharing two{CdO4N2}and one{CdO6}octahedra are connected by phosphonate groups,forming a ribbon,which are cross-linked by 4,4'-bipy ligands,forming a 2D layer.Compound 2 shows a 3D open-framework structure,where chains of corner-sharing{CdO4N}trigonal bipyramids and{PO3C}tetrahedra are cross-linked by 1,4-bib and/or phosphonate groups.A 1D ladder-like chain structure is found in compound 3,where the ladder-like chains made up of corner-sharing{CdO5N}octahedra and{PO3C}tetra hedra are connected by 1,4-ndpaH_(2)^(2-).Both compounds 4 and 5 obtained by the introduction of flexible ligands during the synthesis show a 2D layered structure,which is formed by ligand crosslinking double metal chains.Interestingly,In 4,flexible 1,2-bix was singly protonated,as guest molecules,filled between layer and layer,while flexible ligand 1,3-dpp is absent in 5.Photophysical measurements indicate that compounds 1-5 show ligand-centered emissions. 展开更多
关键词 naphthalene diphosphate N-donor auxiliary ligands crystal structure RIGIDITY flexibility
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Synthesis,structure,and magnetic property of a cobalt(Ⅱ)complex based on pyridyl⁃substituted imino nitroxide radical
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作者 WANG Xiaoling ZHANG Hongwu LIU Daofu 《无机化学学报》 北大核心 2025年第2期407-412,共6页
A new cobalt(Ⅱ)-radical complex:[Co(im4-py)_(2)(PNB)_(2)](im4-py=2-(4'-pyridyl)-4,4,5,5-tetramethylimidazole-1-oxyl,HPNB=p-nitrobenzoic acid)has been synthesized and characterized by X-ray diffraction analysis,el... A new cobalt(Ⅱ)-radical complex:[Co(im4-py)_(2)(PNB)_(2)](im4-py=2-(4'-pyridyl)-4,4,5,5-tetramethylimidazole-1-oxyl,HPNB=p-nitrobenzoic acid)has been synthesized and characterized by X-ray diffraction analysis,elemental analysis,IR,and magnetic properties.X-ray diffraction analysis shows that the complex exists as mononuclear molecules and Co(Ⅱ)ion is four-coordinated with two radicals and two PNB-ligands.The magnetic susceptibility study indicates the complex exhibits weak ferromagnetic interactions between cobalt(Ⅱ)and im4-py radical.The magnetic property is explained by the magnetic and structure exchange mechanism.CCDC:976028. 展开更多
关键词 Co(Ⅱ)complex imino nitroxide radical crystal structure magnetic property
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The synthesis of alcohol ether esters through the catalytic hydrogenation of diethyl oxalate in the Cu-Al systems induced by Al_(2)O_(3) properties
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作者 Peng Wu Lina Ma +3 位作者 Yu Zheng Li Luo Lihong Su Juntian Li 《日用化学工业(中英文)》 北大核心 2025年第9期1100-1111,共12页
The structure-performance relationship of Cu/Al_(2)O_(3) catalysts in the hydrogenation of diethyl oxalate(DEO)for the synthesis of alcohol ether esters has been investigated by various characterization techniques inc... The structure-performance relationship of Cu/Al_(2)O_(3) catalysts in the hydrogenation of diethyl oxalate(DEO)for the synthesis of alcohol ether esters has been investigated by various characterization techniques including XRD,XPS,N2O titration,and 27Al MAS-NMR.The results showed that when the crystal configurations of Al_(2)O_(3) were the same,increasing the specific surface area could effectively refine the size of copper nanoparticles(Cu NPs),and ultimately improve the conversion of DEO.Meanwhile,the smaller size ofγ-Al_(2)O_(3)(HSAl and SBAl)loaded Cu NPs promotes the reaction towards the deep hydrogenation to produce ethanol(EtOH)and ethylene glycol(EG).Besides,the larger size of Cu NPs on the surface of amorphous Al_(2)O_(3)(HTAl and SolAl)resulted in a lower conversion rate,where ethyl glycolate(Egly)is the main product.Despite there are differences in Al^(3+)ionic coordination in Al_(2)O_(3) with different crystal structures,the experimental data showed that the differences in Al^(3+)ionic coordination did not significantly affect the catalytic performance in the hydrogenation reaction.The formation of alcohol-ether ester chemicals is critically dependent on the interactions between Cu sites and acidic sites.Among them,EG and EtOH were dehydrated to form 2-ethoxyethanol via the SN2 mechanism,while Egly and EtOH were reacted to form ethyl ethoxyacetate(EEA)via the SN2 mechanism.This study provides a theoretical basis for the optimization of the coal-based glycol processes to achieve a diversified product portfolio. 展开更多
关键词 oxalate hydrogenation alcohol ether esters Cu-Al catalyst SN2 mechanism
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Synthesis and Coloring Properties of A Novel Garnet-type Green Ceramic Pigment Y_(3)Ga_(3)MgSiO_(12)∶Cr^(3+)
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作者 YANG Sihan ZHANG Qian +4 位作者 ZHAO Chuxin LIU Danhe GONG Xinjiao CHEN Yufei WANG Xuejiao 《发光学报》 北大核心 2025年第4期704-712,共9页
Novel green ceramic pigments Y_(3)Ga_(3)MgSiO_(12)∶xCr^(3+)(x=0−0.2)were successfully synthesized via the conventional solid-state approach.The properties of the pigments were studied by XRD,FE-SEM,UV-Vis spectroscop... Novel green ceramic pigments Y_(3)Ga_(3)MgSiO_(12)∶xCr^(3+)(x=0−0.2)were successfully synthesized via the conventional solid-state approach.The properties of the pigments were studied by XRD,FE-SEM,UV-Vis spectroscopy,XPS,and chromaticity analysis.The findings reveal that the trivalent chromium ions occupy the[Ga1O6]octahedral sites within the garnet lattice,and the relatively weak crystal field environment provided by the matrix endows the pigments with green characteristics.The samples prepared by calcination at 1400℃exhibit the most excellent performance in terms of phase purity,morphology,and color properties.The chromaticity values for the representative sample Y_(3)Ga_(3)MgSiO_(12)∶0.05Cr^(3+)are L^(*)=81.16,a^(*)=−12.53,and b^(*)=12.71,and the color remains stable after the stability test.Moreover,when glazed with Y_(3)Ga_(3)MgSiO_(12)∶xCr^(3+)(x=0−0.2)pigments,the smooth glaze surfaces exhibit vivid and saturated green tones,demonstrating their remarkable coloring capabilities and promising potential as a practical pigment for medium-temperature applications.This research underscores the vast application prospects of Y_(3)Ga_(3)MgSiO_(12)∶Cr^(3+)as an innovative green ceramic pigment. 展开更多
关键词 GARNET green pigments Cr^(3+)doping
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ESCRT Mechanism-mediated Repair of Plasma Membrane Damage Induced by Regulatory Cell Death
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作者 FENG Tian-Yang DENG Le +2 位作者 XU Gou LI Li GUO Miao-Miao 《生物化学与生物物理进展》 北大核心 2025年第5期1099-1112,共14页
The plasma membrane(PM)plays an essential role in maintaining cell homeostasis,therefore,timely and effective repair of damage caused by factors such as mechanical rupture,pore-forming toxins,or pore-forming proteins ... The plasma membrane(PM)plays an essential role in maintaining cell homeostasis,therefore,timely and effective repair of damage caused by factors such as mechanical rupture,pore-forming toxins,or pore-forming proteins is crucial for cell survival.PM damage induces membrane rupture and stimulates an immune response.However,damage resulting from regulated cell death processes,including pyroptosis,ferroptosis,and necroptosis,cannot be repaired by simple sealing mechanisms and thus,requires specialized repair machinery.Recent research has identified a PM repair mechanism of regulated cell death-related injury,mediated by the endosomal sorting complexes required for transport(ESCRT)machinery.Here,we review recent progress in elucidating the ESCRT machinery-mediated repair mechanism of PM injury,with particular focus on processes related to regulated cell death.This overview,along with continued research in this field,may provide novel insights into therapeutic targets for diseases associated with dysregulation of regulated cell death pathways. 展开更多
关键词 ESCRT PYROPTOSIS ferroptosis NECROPTOSIS plasma membrane repair
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Porous spherical MnCo_(2)S_(4) as high⁃performance electrode material for hybrid supercapacitors
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作者 LUO Min WANG Xiaonan +3 位作者 ZHANG Yaqin PANG Tian LI Fuzhi SHI Pu 《无机化学学报》 北大核心 2025年第2期413-424,共12页
Porous spherical MnCo_(2)S_(4) was synthesized by a simple solvothermal method.Thanks to the well-designedbimetallic composition and the unique porous spherical structure,the MnCo_(2)S_(4) electrode exhibited an excep... Porous spherical MnCo_(2)S_(4) was synthesized by a simple solvothermal method.Thanks to the well-designedbimetallic composition and the unique porous spherical structure,the MnCo_(2)S_(4) electrode exhibited an exceptionalspecific capacitance of 190.8 mAh·g^(-1)at 1 A·g^(-1),greatly higher than the corresponding monometallic sulfides MnS(31.7 mAh·g^(-1))and Co_(3)S_(4)(86.7 mAh·g^(-1)).Impressively,the as-assembled MnCo_(2)S_(4)||porous carbon(PC)hybridsupercapacitor(HSC),showed an outstanding energy density of 76.88 Wh·kg^(-1)at a power density of 374.5 W·kg^(-1),remarkable cyclic performance with a capacity retention of 86.8% after 10000 charge-discharge cycles at 5 A·g^(-1),and excellent Coulombic efficiency of 99.7%. 展开更多
关键词 transitional metal sulfide SUPERCAPACITOR porous spherical structure
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Time-resolved Electroluminescence of Charge Carrier Dynamics in Multiple-emitting-layer White QLEDs with Polyethyleneimine Interlayers
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作者 YAN Shanshan WANG Shen +2 位作者 LIANG Wencheng LIU Weiwei KONG Youchao 《发光学报》 北大核心 2025年第10期1851-1861,共11页
The charge carrier transport and recombination dynamics in the quantum dots-based light-emitting diodes(QLEDs)featuring multiple emitting layers(M-EMLs)has a great impact on the device performance.In this work,QLEDs b... The charge carrier transport and recombination dynamics in the quantum dots-based light-emitting diodes(QLEDs)featuring multiple emitting layers(M-EMLs)has a great impact on the device performance.In this work,QLEDs based on M-EMLs separated by polyethyleneimine ethoxylated(PEIE)layer with different stacking sequences of blue(B),green(G),and red(R)QDs layer were used to intuitively explore the injection,transportation and recombination processes of the charge carriers in QLEDs by using the time-resolved electroluminescence(TrEL)spectra.From the TrEL spectra mea-surements,green and red emissions were obtained first in the QLEDs with the EMLs sequences of G/PEIE/B/PEIE/R and B/PEIE/R/PEIE/G along the direction of light emission,respectively.While the QLEDs adopt EMLs sequences of B/PEIE/G/PEIE/R,the blue,green and red emissions were obtained nearly at the same time.The above phenomenon can be attributed to different charge carrier transmission and radiation recombination process in the EMLs due to different valence band offsets and conduction band offsets between R-,G-and B-QDs by using different sequences of EMLs.White emission with coordi-nates of(0.31,0.31)and correlated color temperature(CCT)of 5916 K was obtained in the QLEDs with the EMLs se-quences of B/PEIE/G/PEIE/R,which can be attributed to the relative uniform emission of B-,G-and R-QDs due to the effec-tive injection and radiation recombination of charge carriers in each of the EMLs.The above results have great significance for further understanding and improving the performance of QLEDs with M-EMLs. 展开更多
关键词 white QLEDs multiple emitting layers TrEL spectra charge carrier dynamics
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Inhibitory effect of the interlayer of two-dimensional vermiculite on the polysulfide shuttle in lithium-sulfur batteries
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作者 CHEN Xiaoli LUO Zhihong +3 位作者 XIONG Yuzhu WANG Aihua CHEN Xue SHAO Jiaojing 《无机化学学报》 北大核心 2025年第8期1661-1671,共11页
A functional interlayer based on two-dimensional(2D)porous modified vermiculite nanosheets(PVS)was obtained by acid-etching vermiculite nanosheets.The as-obtained 2D porous nanosheets exhibited a high specific surface... A functional interlayer based on two-dimensional(2D)porous modified vermiculite nanosheets(PVS)was obtained by acid-etching vermiculite nanosheets.The as-obtained 2D porous nanosheets exhibited a high specific surface area of 427 m^(2)·g^(-1)and rich surface active sites,which help restrain polysulfides(LiPSs)through good physi-cal and chemical adsorption,while simultaneously accelerating the nucleation and dissolution kinetics of Li_(2)S,effec-tively suppressing the shuttle effect.The assembled lithium-sulfur batteries(LSBs)employing the PVS-based inter-layer delivered a high initial discharge capacity of 1386 mAh·g^(-1)at 0.1C(167.5 mAh·g^(-1)),long-term cycling stabil-ity,and good rate property. 展开更多
关键词 vermiculite nanosheets two-dimensional materials INTERLAYER shuttle effect lithium-sulfur batteries
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Structure and magnetic properties of Mn(Ⅱ)coordination polymers regulated by N-auxiliary ligands
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作者 LIU Xiaxia MA Xiaofang +2 位作者 GUO Luxia HAN Xianda FENG Sisi 《无机化学学报》 北大核心 2025年第3期587-596,共10页
Two new Mn(Ⅱ)coordination polymers,namely{[Mn_(2)(HL)(phen)_(3)(H_(2)O)_(2)]·7.5H_(2)O}_n(1)and[Mn_(4)(HL)_(2)(1,4-bib)_(3)(H_(2)O)_(2)]_n(2),were synthesized under hydrothermal conditions by using Mn(Ⅱ)ions an... Two new Mn(Ⅱ)coordination polymers,namely{[Mn_(2)(HL)(phen)_(3)(H_(2)O)_(2)]·7.5H_(2)O}_n(1)and[Mn_(4)(HL)_(2)(1,4-bib)_(3)(H_(2)O)_(2)]_n(2),were synthesized under hydrothermal conditions by using Mn(Ⅱ)ions and 6-(3',4'-dicarboxylphenoxy)-1,2,4-benzenetricarboxylic acid(H_(5)L)in the presence of N-auxiliary ligands 1,10-phenanthroline(phen)and1,4-bis(1H-imidazol-1-yl)benzene(1,4-bib).The structures of coordination polymers 1 and 2 were characterized by infrared spectroscopy,single-crystal X-ray diffraction,thermogravimetric analysis,and powder X-ray diffraction.Single-crystal X-ray diffraction reveals that 1 has a 1D chain structure based on binuclear Mn(Ⅱ)units,while 2 features a(3,8)-connected 3D network structure based on tetranuclear Mn(Ⅱ)units.Magnetic studies show that 1 and 2exhibit antiferromagnetic interactions between manganese ions.2 shows stronger antiferromagnetic interactions due to the shorter Mn…Mn distances within the tetranuclear manganese units.CCDC:2357601,1;2357602,2. 展开更多
关键词 coordination polymers crystal structures binuclear Mnunit tetranuclear Mnunit MAGNETISM
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Recent progress on the use of lignin-based porous carbon in supercapacitors
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作者 ZHA Ding-chen WANG Jia-heng +6 位作者 Hao Rui-xiang Wu Yun-feng LI Xiu-he ZHAO Jia-wen LI Wen PIAO Wen-xiang JIANG Nan-zhe 《新型炭材料(中英文)》 北大核心 2025年第1期50-80,共31页
With the development of electronics and portable devices,there is a significant drive to develop electrode materials for supercapacitors that are lightweight,economical,and provide high energy and power densities.Lign... With the development of electronics and portable devices,there is a significant drive to develop electrode materials for supercapacitors that are lightweight,economical,and provide high energy and power densities.Lignin-based porous carbons have recently been extensively studied for en-ergy storage applications because of their characteristics of large specific surface area,easy doping,and high conductivity.Significant progress in the synthesis of porous carbons derived from lignin,using different strategies for their preparation and modification with heteroatoms,metal oxides,met-al sulfides,and conductive polymers is considered and their electrochemical performances and ion storage mechanisms are discussed.Considerable fo-cus is directed towards the challenges encountered in using lignin-based por-ous carbons and the ways to optimize specific capacity and energy density for supercapacitor applications.Finally,the limitations of existing technolo-gies and research directions for improving the performance of lignin-based carbons are discussed. 展开更多
关键词 LIGNIN Porous carbon SUPERCAPACITOR CARBONIZATION
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Effect of reduced graphene oxide produced by plant extract on anti-corrosion behaviour of epoxy coating
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作者 FOROUZESH Shervin JAFARI Hassan SADEGHZADEH Ahmad 《Journal of Central South University》 2025年第3期820-836,共17页
Graphene oxide (GO) reduced by Stachys lavandulifolia extract (SLE) was produced and characterised. The anti-corrosion behaviour of epoxy coatings containing GO and rGO nanosheets was investigated. FESEM-EDS, FT-IR, a... Graphene oxide (GO) reduced by Stachys lavandulifolia extract (SLE) was produced and characterised. The anti-corrosion behaviour of epoxy coatings containing GO and rGO nanosheets was investigated. FESEM-EDS, FT-IR, and Raman spectroscopy were used to examine the microstructure and chemical composition of the nanosheets and epoxy coatings. EIS experiment was used to explore the corrosion behaviour of the coatings. The O/C ratio for GO and rGO-SLE was found to be 2.5 and 4.5, indicating a decrease in the carbon content after the reduction of GO, confirming the adsorption of SLE onto the GO nanosheets. The successful reduction of GO in the presence of SLE particles was confirmed by disappearing the C=O peak and a significant decrease in the C-O-C bond intensity. The epoxy/rGO- SLE coatings exhibited the highest double-layer thickness and excellent corrosion resistance compared to neat epoxy and epoxy/GO coatings, emphasizing the significant role of rGO in enhancing the protective performance of epoxy coatings. The highest values for total charge transfer and film resistances and the inhibition efficiency were observed to be 6529 Ω·cm^(2) and 90%, respectively, for the epoxy/rGO-SLE coated steel plate. It was also found that the epoxy/0.15 wt.% rGO-SLE coating demonstrates the best corrosion resistance performance. 展开更多
关键词 graphene oxide coating EPOXY corrosion NANOSHEET Stachys lavandulifolia
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Effect of post weld heat treatment on grain boundary character distribution and corrosion resistance of friction stir welded armourgrade nickel and molybdenum-free high-nitrogen austenitic stainless steel
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作者 Arun Kumar Gurrala Raffi Mohammed G Madhusudhan Reddy 《Defence Technology(防务技术)》 2025年第9期246-261,共16页
This study examines the effects of friction stir welding(FSW)and post-weld heat treatment(PWHT)on the grain boundary character distribution and corrosion resistance of cross sectional(top and bottom)regions of nickel-... This study examines the effects of friction stir welding(FSW)and post-weld heat treatment(PWHT)on the grain boundary character distribution and corrosion resistance of cross sectional(top and bottom)regions of nickel-and molybdenum-free high-nitrogen austenitic stainless steel(HNASS).FSW at 400 rpm and 30 mm/min resulted in finer grains(4.18μm)and higher coincident site lattice(CSL)boundaries(32.3%)at the top of the stir zone(SZ)due to dynamic recrystallization(DRX).PWHT at 900℃for 1 h led to grain coarsening(12.91μm the bottom SZ)but enhanced CSL boundaries from 24.6%to 30.2%,improving grain boundary stability.PWHT reduced the kernel average misorientation(KAM)by 14.9%in the SZ-top layer and 20.4%in the SZ-bottom layer,accompanied by a 25%decrease in hardness in the SZ-top layer and 26.7%in the SZ-bottom layer,indicating strain recovery and reduced dislocation density.Potentiodynamic polarization tests(PDP)showed a 18%increase in pitting potential and a 76%reduction in corrosion rate after PWHT.The improvement in corrosion resistance is attributed to the increase inΣ3 twin boundaries,which enhance grain boundary stability and reduce susceptibility to localized corrosion.These findings highlight the role of PWHT in refining the microstructure and strengthening corrosion resistance,making HNASS a promising material for demanding applications. 展开更多
关键词 Nickel and molybdenum free high-nitrogen austenitic stainless steel Friction stir welding Post-weld heat treatment Electron backscattered diffraction Microstructural gradients Pitting corrosion resistance Coincident site lattice Grain boundary characteristic distribution
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Improving the oxidation resistance of HfB_(2)-SiC coatings on carbon/carbon composites by CeO_(2) doping
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作者 HE Chang-lin SHANG Zhi-chao +10 位作者 WANG Wei-guang LI Xiang-ming WANG Kun CHEN Yue-xing BAI Xin-tan WANG Pei-pei JI Xiang REN Xuan-ru Evgeny A Levashov Ph V Kiryukhantsev-Korneev FENG Pei-zhong 《新型炭材料(中英文)》 北大核心 2025年第3期688-702,共15页
To improve the oxidation resistance of HfB_(2)-SiC coatings on carbon/carbon composites at 1700°C in air,CeO_(2) was introduced to improve oxygen blocking and its mechanism was investigated.During the rapid oxida... To improve the oxidation resistance of HfB_(2)-SiC coatings on carbon/carbon composites at 1700°C in air,CeO_(2) was introduced to improve oxygen blocking and its mechanism was investigated.During the rapid oxidation stage,CeO_(2) accelerated the formation of a multiphase glass layer on the coating surface.The maximum oxidation rates of CeO_(2)-HfB2-SiC coatings with 1%,3%,and 5%CeO_(2) were 24.1%,20.3%,and 53.2%higher than that of the unmodified HfB2-SiC coating,respectively.In the stable oxidation stage,the maximum oxidation rates of coatings with 1%and 3%CeO_(2) decreased by 31.4%and 21.9%,respectively,demonstrating adequate inert protection.CeO_(2) is a“coagulant”and“stabilizer”in the composite glass layer.However,increasing the CeO_(2) content accelerates the reaction between the SiO_(2) glass phase and SiC,leading to a higher SiO_(2) consumption and reduced self-healing ability of the glass layer.The 1%CeO_(2)-60%HfB2-39%SiC coating showed improved glass layer viscosity and stability,moderate SiO_(2) consumption,and better self-healing ability,significantly boosting the oxidation protection of the coating. 展开更多
关键词 HfB_(2)-SiC coatings CeO_(2) Oxidation resistance Self-healing ability MECHANISM
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Growth kinetics of borided 316 L stainless steel obtained by selective laser melting
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作者 DEMIRCI Selim TÜNÇAY Mehmet Masum 《Journal of Central South University》 2025年第2期332-349,共18页
Selective laser melting(SLM)is a cost-effective 3 D metal additive manufacturing(AM)process.However,AM 316 L stainless steel(SS)has different surface and microstructure properties as compared to conventional ones.Bori... Selective laser melting(SLM)is a cost-effective 3 D metal additive manufacturing(AM)process.However,AM 316 L stainless steel(SS)has different surface and microstructure properties as compared to conventional ones.Boriding process is one of the ways to modify and increase the surface properties.The aim of this study is to predict and understand the growth kinetic of iron boride layers on AM 316 L SS.In this study,the growth kinetic mechanism was evaluated for AM 316 L SS.Pack boriding was applied at 850,900 and 950℃,each for 2,4 and 6 h.The thickness of the boride layers ranged from(1.8±0.3)μm to(27.7±2.2)μm.A diffusion model based on error function solutions in Fick’s second law was proposed to quantitatively predict and elucidate the growth rate of FeB and Fe_(2)B phase layers.The activation energy(Q)values for boron diffusion in FeB layer,Fe_(2)B layer,and dual FeB+Fe_(2)B layer were found to be 256.56,161.61 and 209.014 kJ/mol,respectively,which were higher than the conventional 316 L SS.The findings might provide and open new directions and approaches for applications of additively manufactured steels. 展开更多
关键词 316L stainless steel BORIDING KINETICS additive manufacturing selective laser melting
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