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Optimized Copper Distribution and Enhanced Coercivity in PrO2-Doped Sm2Co17-Type Magnets 认领 引用
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作者 Qi-Qi Yang Jun Li +3 位作者 Yu-Cheng Hu Xiao-Yu Zhu Tao Yuan Ying Liu 《Rare Metals》 SCIE EI CAS CSCD 2026年第1期237-250,共14页
A rational design of Cu distribution is crucial for achieving optimal magnetic properties in Sm2Co17-type magnets.In this study,nanostructured PrO2 powders were employed to induce Cu redistribution at grain b... A rational design of Cu distribution is crucial for achieving optimal magnetic properties in Sm2Co17-type magnets.In this study,nanostructured PrO2 powders were employed to induce Cu redistribution at grain boundaries while preserving the cellular microstructure.The corresponding coercivity(Hcj),remanence(Br),and maximum energy product((BH)max) were significantly enhanced in the 1 wt% PrO2-doped magnet,with improvements of 4.36 kOe,0.22 kGs and 1.1 MGOe,respectively.These results surpass those of most rare-earth-oxide-doped Sm2Co17-type magnets reported to date.Microstructure characterization and micromagnetic simulations confirm that the coarse Cu-rich phase induced by PrO2 doping enhances the pinning strength at grain boundaries,thereby contributing to the observed coercivity enhancement.The(Sm1-xPrx)2Co17 phase exhibits a higher substitution energy barrier at Co sites,which promotes Cu migration toward grain boundaries.Meanwhile,the(Sm1-xPrx)2Co17phase also slightly improves the remanence in the 1 wt% PrO2-doped magnet due to its higher saturation magnetization(Ms).However,excessive PrO2 doping(2 wt%),while further increasing coercivity by 6.45 kOe,adversely affects squareness and remanence.This study demonstrates a viable strategy for fabricating high-performance Sm2Co17-type permanent magnets while enabling efficient utilization of rare-earth Pr oxides. 展开更多
关键词 cellular structure Cu migration PrO2-doping Sm2Co17-type magnets
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二陈汤通过Nrf2/HO-1信号通路调节氧化应激和代谢紊乱改善SiO2诱导的肺损伤 认领 引用
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作者 芦俊 朱馨怡 +6 位作者 刘子怡 胡吉霞 陈佳露 肖荣 王智槟 刘畅 卢芳国 《中国实验方剂学杂志》 CAS CSCD 北大核心 2026年第13期32-42,共11页
目的:观察二陈汤对二氧化硅(SiO2)诱导肺损伤大鼠的保护作用,探讨其作用机制。方法:采用一次性气管滴注50 g·L-1 SiO2混悬液建立肺损伤大鼠模型。将30只雄性SD大鼠随机分为正常组,模型组,二陈汤低、高剂量组(4.5、9 g·k... 目的:观察二陈汤对二氧化硅(SiO2)诱导肺损伤大鼠的保护作用,探讨其作用机制。方法:采用一次性气管滴注50 g·L-1 SiO2混悬液建立肺损伤大鼠模型。将30只雄性SD大鼠随机分为正常组,模型组,二陈汤低、高剂量组(4.5、9 g·kg-1·d-1)和地塞米松组(0.2 mg·kg-1·d-1),连续干预4周。苏木素-伊红(HE)染色观察肺组织病理变化;生化法检测肺组织丙二醛(MDA)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GPX)水平;实时荧光定量聚合酶链式反应(Real-time PCR)、蛋白免疫印迹法(Western blot)及免疫荧光法检测核因子E2相关因子2(Nrf2)/血红素加氧酶-1(HO-1)信号通路关键分子的表达。超高效液相色谱-串联质谱法(UPLC-MS/MS)鉴定二陈汤主要活性成分,结合分子对接技术评估其核心成分与Nrf2/HO-1的结合能力。超高效液相色谱-四极杆-飞行时间质谱法(UPLC-Q-TOF-MS)非靶向代谢组学技术分析肺组织代谢谱,相关性分析筛选与Nrf2/HO-1信号通路密切相关的差异代谢物及指标。结果:与正常组比较,模型组大鼠体质量增长率显著降低,肺指数显著升高,肺组织MDA含量显著升高,SOD和GPX活性明显降低,Nrf2 mRNA及蛋白表达明显降低,HO-1、GPX4蛋白表达明显降低,Kelch样ECH关联蛋白1(Keap1)蛋白明显升高(P<0.05,P<0.01)。与模型组比较,二陈汤明显减缓SiO2诱导的大鼠体质量下降趋势(P<0.05);减轻大鼠肺泡炎性细胞浸润和矽结节形成;降低肺组织MDA含量,提高SOD和GPX活性(P<0.05,P<0.01)。UPLC-MS/MS和分子对接结果显示橙皮苷、甘草酸等二陈汤核心成分与Nrf2/HO-1具有强结合亲和力;分子生物学实验表明二陈汤可促进Nrf2核转位,上调HO-1、GPX4 mRNA及蛋白表达,下调Keap1表达(P<0.05,P<0.01)。代谢组学结果显示,二陈汤可回调SiO2诱导的亚油酸、谷氨酰胺等代谢物异常表达(P<0.05,P<0.01)。相关性分析表明,Nrf2、HO-1与SOD、GPX呈明显正相关(P<0.05,P<0.01),与谷氨酰胺、丝氨酸呈明显负相关(P<0.05,P<0.01)。结论:二陈汤可能通过核心成分激活Nrf2/HO-1信号通路,调节氧化应激及代谢紊乱,从而改善SiO2诱导的大鼠肺损伤,为防治职业性肺损伤提供实验依据。 展开更多
关键词 二陈汤 二氧化硅(SiO2) 肺损伤 核因子E2相关因子2(Nrf2)/血红素加氧酶-1(HO-1)信号通路 氧化应激 代谢紊乱
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TiO2-Ag双功能涂层协同修饰的SiO基复合负极材料制备及高容量锂离子存储性能研究 认领 引用
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作者 吴霞 张海燕 洪浩群 《新能源进展》 CSCD 北大核心 2026年第2期167-175,共9页
为满足锂离子电池领域对高容量、长寿命储能技术的迫切需求,硅基负极材料因其高理论容量优势成为产业化应用研究的重点。然而,硅(Si)在锂化过程中严重的体积膨胀制约了其应用。与Si相比,一氧化硅(SiO)的体积膨胀虽有所降低,但仍存在本... 为满足锂离子电池领域对高容量、长寿命储能技术的迫切需求,硅基负极材料因其高理论容量优势成为产业化应用研究的重点。然而,硅(Si)在锂化过程中严重的体积膨胀制约了其应用。与Si相比,一氧化硅(SiO)的体积膨胀虽有所降低,但仍存在本征电导率低和初始库仑效率低等问题。为解决SiO材料的缺陷,采用二氧化钛(TiO2)和银(Ag)双功能涂层修饰策略,通过球磨法和溶胶凝胶法制备了TiO2和Ag双涂层修饰的SiO基复合材料(D-SiO@TiO2@Ag)。电化学测试表明,在0.2 A/g电流密度下,该复合材料经过100次循环后可逆容量为1164.3 mA·h/g,容量保持率为73.29%,显著高于未修饰SiO的547.9 mA·h/g和34.16%。D-SiO@TiO2@Ag复合材料结合了SiO的高容量和TiO2的缓解体积膨胀优势,同时通过Ag纳米颗粒提升了导电性和电荷传输性能,为新一代高容量、高稳定性的硅基负极材料提供了设计思路。 展开更多
关键词 纳米复合材料 锂离子电池 硅基负极 银纳米颗粒 SiO TiO2
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考虑纳米SiO2颗粒作用的Cu-SiO2-Cu接触界面摩擦性能研究 认领 引用
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作者 马金兰 张肖 +2 位作者 佟瑞庭 张皓宸 张润成 《表面技术》 EI CAS CSCD 北大核心 2026年第13期99-110,共12页
目的为揭示空间尘埃环境纳米SiO2颗粒侵入软金属接触界面后的摩擦机理,本文系统研究了颗粒尺寸、形貌等因素对接触界面摩擦行为的影响,为空间机构Cu润滑膜的设计与防护提供理论依据。方法采用分子动力学方法构建Cu-SiO2-Cu三体纳... 目的为揭示空间尘埃环境纳米SiO2颗粒侵入软金属接触界面后的摩擦机理,本文系统研究了颗粒尺寸、形貌等因素对接触界面摩擦行为的影响,为空间机构Cu润滑膜的设计与防护提供理论依据。方法采用分子动力学方法构建Cu-SiO2-Cu三体纳米接触模型,将Cu视为比较厚的软金属润滑膜,引入不同形貌的SiO2颗粒,在不同条件下开展研究。结果颗粒尺度对界面摩擦具有显著的尺寸效应,当颗粒半径为1nm时,强黏附与局部变形导致平均摩擦力最高;随着颗粒半径增大至2nm,滚动作用增强,摩擦力降低;当继续增大颗粒尺寸时,接触面积增大、滚动被抑制,摩擦力开始回升。下压深度增加会导致接触区塑性变形与犁削作用增强,使摩擦力大幅度上升。滑动速度对摩擦力的影响表现出先减小后增大的特征。相较于光滑球形颗粒,具有表面凸起的近球形颗粒在接触表面会产生更强的应力集中与犁沟效应,并伴随温度急剧上升,导致摩擦水平进一步增加。结论SiO2颗粒作为第三体时,对于颗粒适中且表面平滑的情况,体系可形成滚-滑混合运动并表现出“纳米轴承效应”;颗粒过小或形貌尖锐时,黏附与犁沟共同主导摩擦,能量耗散加剧;过大尺寸、过大下压深度以及过高滑动速度则通过几何约束、剪切集中和热效应使摩擦力升高。 展开更多
关键词 分子动力学 SiO颗粒 Cu-SiO2-Cu 三体接触 滑动接触
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丝胶蛋白/SiO2纳米复合溶胶对芳纶服用性能的影响 认领 引用
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作者 田恬 尉霞 +3 位作者 康青青 罗璟娴 王庆博 刘阳 《纺织科技进展》 CAS 2026年第1期27-30,共4页
为解决芳纶织物服用性能不足的问题,制备丝胶蛋白/SiO2纳米复合溶胶并将其整理到间位芳纶上,研制出不同复合溶胶的织物试样,并探究复合溶胶浓度对芳纶织物服用性能的影响。结果表明,当复合溶胶浓度为4%时,整理后织物的各项性能较好。在... 为解决芳纶织物服用性能不足的问题,制备丝胶蛋白/SiO2纳米复合溶胶并将其整理到间位芳纶上,研制出不同复合溶胶的织物试样,并探究复合溶胶浓度对芳纶织物服用性能的影响。结果表明,当复合溶胶浓度为4%时,整理后织物的各项性能较好。在最优整理条件(浓度4%)下,间位芳纶的回潮率、导湿性、抗静电性及透湿性均有所改善,而透气性略微下降,总体而言,芳纶织物的服用性能得到改善。 展开更多
关键词 丝胶蛋白/SiO2纳米复合溶胶 间位芳纶 服用性能
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ZnO-NPs+SiO2-NPs提高洋桔梗幼苗抗温度胁迫能力的研究 认领 引用
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作者 刘城 郝璇 +2 位作者 高成烨 常艺曼 文锦芬 《广西植物》 CAS CSCD 北大核心 2026年第7期1224-1233,共10页
温度是影响花卉生长发育的重要因子。氧化锌纳米粒子(ZnO-NPs)和二氧化硅纳米粒子(SiO2-NPs)在增强植物抗逆性方面展现出潜力。为明确ZnO-NPs+SiO2-NPs预处理对洋桔梗在温度胁迫下的调控机制,该研究以洋桔梗幼苗为材料,首先采用... 温度是影响花卉生长发育的重要因子。氧化锌纳米粒子(ZnO-NPs)和二氧化硅纳米粒子(SiO2-NPs)在增强植物抗逆性方面展现出潜力。为明确ZnO-NPs+SiO2-NPs预处理对洋桔梗在温度胁迫下的调控机制,该研究以洋桔梗幼苗为材料,首先采用正交试验设计[L 9(34)],通过ZnO-NPs和SiO2-NPs在不同浓度、配比及喷施次数下对洋桔梗幼苗生长的影响,筛选最优喷洒方案,然后预处理幼苗,并分别进行42℃(24 h)高温和4℃(24 h)低温胁迫,测定生理指标及相关抗逆基因表达。结果表明:(1)当纳米粒子总浓度为0.03%(m/V),ZnO-NPs∶SiO2-NPs配比为1∶2(V/V),叶面喷施2次时,幼苗生长最佳。(2)ZnO-NPs+SiO2-NPs预处理提高了正常生长条件下叶片叶绿素含量;降低了42℃和4℃胁迫下的相对电导率、丙二醛(MDA)含量和过氧化氢(H2O2)含量;提高了超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和过氧化物酶(POD)的活性。(3)ZnO-NPs+SiO2-NPs预处理上调了Mn-SOD、Cu/Zn-SOD、Fe-SOD、CAT和POD基因的表达水平。(4)42℃胁迫下,ZnO-NPs+SiO2-NPs预处理促进了热休克蛋白90基因(HSP 90)的表达和4℃胁迫下冷调节基因(COR 413)的表达。综上认为,适宜的ZnO-NPs+SiO2-NPs预处理通过促进抗氧化酶活性的升高及相关抗逆基因的表达来增强洋桔梗幼苗对温度胁迫的抗性。该研究揭示了ZnO-NPs+SiO2-NPs预处理增强洋桔梗抗温度胁迫的分子机制,并为纳米材料在花卉抗逆研究中提供了理论依据。 展开更多
关键词 氧化锌纳米粒子(ZnO-NPs) 二氧化硅纳米粒子(SiO 2-NPs) 洋桔梗幼苗 抗氧化酶活性 基因表达
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CaO含量对SiO2-Al2O3-CaO系轻质陶粒性能的影响及机理分析 认领 引用
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作者 张祎欢 范海宏 +2 位作者 李俊杰 王玉浓 吴瑞 《新型建筑材料》 2026年第8期88-93,99,共6页
以煤矸石和垃圾焚烧飞灰等工业固废为主要原料,研究CaO含量(0.53%~33.61%)对SiO2-Al2O3-CaO系轻质陶粒物理性能及矿物组成的影响规律。结果表明,随着CaO含量增加,陶粒表观密度与单颗粒强度呈现减-增-减的非单调变化趋势,膨胀率与吸水率... 以煤矸石和垃圾焚烧飞灰等工业固废为主要原料,研究CaO含量(0.53%~33.61%)对SiO2-Al2O3-CaO系轻质陶粒物理性能及矿物组成的影响规律。结果表明,随着CaO含量增加,陶粒表观密度与单颗粒强度呈现减-增-减的非单调变化趋势,膨胀率与吸水率则呈相反规律。当CaO含量为11.56%、烧结温度1180℃时,可获得综合性能最优的陶粒:单颗粒强度1.75 MPa,表观密度471.43 kg/m3,吸水率3.85%。XRD与SEM-EDS分析表明,钙长石是陶粒膨胀过程的主导晶相,其含量随CaO含量的增加而升高。机理研究表明,适量CaO既可降低熔体黏度促进气体包裹,又能与硅铝组分反应形成钙长石骨架,二者协同作用实现陶粒的轻质化。 展开更多
关键词 SiO2-Al2O3-CaO系 陶粒 工业固废 钙长石 CaO含量 烧结机理
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Fe2O3-SiO2复合气凝胶材料的制备及耐温性能 认领 引用 被引量：2
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作者 侯建业 张忠伦 +2 位作者 付晓晴 王明铭 刘振森 《耐火材料》 CAS 北大核心 2025年第2期133-137,共5页
为了提高SiO2气凝胶在高温下的隔热性能,以溶胶-凝胶两步法制备SiO2前驱体溶液,将遮光剂Fe2O3粉末添加到SiO2前驱体溶液中,结合二氧化碳超临界干燥技术,制备出Fe2O3-SiO2复合气凝胶,探究Fe2O3遮光剂的添... 为了提高SiO2气凝胶在高温下的隔热性能,以溶胶-凝胶两步法制备SiO2前驱体溶液,将遮光剂Fe2O3粉末添加到SiO2前驱体溶液中,结合二氧化碳超临界干燥技术,制备出Fe2O3-SiO2复合气凝胶,探究Fe2O3遮光剂的添加(Fe2O3外加质量分数分别为0、0.2%、0.5%、1.0%和3.0%)对气凝胶的影响。结果表明:1)Fe2O3添加到气凝胶中,不会影响气凝胶的形貌;Fe2O3的添加抑制了材料因高温造成的质量损失,提高了复合材料在高温下的稳定性。2)温度低于800℃时,Fe2O3外加量为0.5%(w)的试样,其热导率最低,隔热性能最好;而在800~1000℃温度下,Fe2O3外加量为1%(w)的试样,其热导率最低,仍保持较好的纳米多孔结构。3)通过控制Fe2O3外加量,可以得到适用于不同温度段的复合气凝胶。 展开更多
关键词 Fe2O3-SiO2复合气凝胶 遮光剂 孔结构 热导率 高温性能
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A novel fluoroapatite-type phosphor Ca2Y8(BO4)2(SiO4)4F2Eu3+ with high quantum efficiency and good thermal stability for multimodal applications 认领 引用 被引量：1
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作者 Zhenyun Wang Tian Tian +7 位作者 Weiwei Wang Yao Cheng Yao Zheng Jiaqi Gao Jiahui Ru Yaoqing Chu Jun Zhou Jiayue Xu 《Journal of Rare Earths》 SCIE EI CAS CSCD 2025年第10期2065-2076,I0001,共12页
A novel Eu3+-doped fluorapatite red phosphor Ca2Y8(BO4)2(SiO4)4F2Eu3+with pure phase was synthesized in this study.Density functional theory(DFT)calculation and diffuse reflection spectrum a... A novel Eu3+-doped fluorapatite red phosphor Ca2Y8(BO4)2(SiO4)4F2Eu3+with pure phase was synthesized in this study.Density functional theory(DFT)calculation and diffuse reflection spectrum analysis reveal its potential as a matrix for phosphors excited by ultraviolet light.Eu3+has a7F0→5L6transition at 394 nm,and the prepared phosphor exhibits a high emission intensity at 614 nm,which may be attributed to the5D0-7F2energy transition at the lower symmetry site of Eu3+.The optimal doping concentration of the phosphor is determined to be 11 mol%,with concentration quenching attributed to the exchange interaction mechanism.The overall color purity of the phosphor is up to 99.88%,with an internal quantum efficiency as high as 91.15%.Notably,Ca2Y8(BO4)2(SiO4)4F2:11 mol%Eu3+(CYBSF:11 mol%Eu3+)phosphors exhibit good thermal stability,with a thermal quenching temperature(T1/2)of 552 K and the intensity of emission at 423 K still at 88.89%of that at 298 K.The activation energy of the phosphor is up to 0.30287 eV.Its comprehensive luminescence performance surpasses that of commercial red phosphor,making it suitable for near ultraviolet excited warm white light emitting diode(NUV-WLED)with a high color rendering index(Ra=82)and a correlated color temperature(CCT)of 4339 K.Moreover,the phosphor achieves latent fingerprint visualization and anti-counterfeiting ink on different material surfaces:glass,aluminum foil,plastic and paper.Overall,the fluorapatite CYBSF:11 mol%Eu3+phosphor holds great potential for multimodal applications due to its high quantum efficiency and good thermal stability. 展开更多
关键词 Eu3+-doped Ca2Y8(BO4)2(SiO4)4F2 Fluoroapatite High quantum efficiency Thermal stability Multimodal applications Rare earths
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Preparation and photocatalytic activity of Cu2+-doped TiO2/SiO2 认领 引用 被引量：9
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作者 Ru-fen Chen Cui-xuan Zhang +1 位作者 Juan Deng Guo-qiang Song 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS 2009年第2期220-225,共6页
Cu^2+-doped nanostructured TiO2-coated SiO2(TiO2/SiO2)particles were prepared by the layer-by-layer assembly technique and their photocatalytic property was studied.TiO2 colloids were synthesized by the sol-gel method... Cu^2+-doped nanostructured TiO2-coated SiO2(TiO2/SiO2)particles were prepared by the layer-by-layer assembly technique and their photocatalytic property was studied.TiO2 colloids were synthesized by the sol-gel method using TiOSO4 as a precursor.The experimental results showed that TiO2 nanopowders on the surface of SiO2 particles were well distributed and compact.The amount of TiO2 increased with the increase in coating layers.The shell structure appeared to be composed of anatase titania nanocrystals at 550℃.The 2-layer coated TiO2 particles on the surface showed a higher degradation rate compared with all the different-layer samples.The photocatalytic activity of Cu^2+-doped TiO2/SiO2 was higher than that ofundoped TiO2/SiO2.The optimum dopant content was about 0.10wt%. 展开更多
关键词 nanostructured TiO2 SiO2 particles layer-byqayer assembly Cu^2+-doped photocatalytic activity
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Simulated-sunlight-activated photocatalysis of Methylene Blue using cerium-doped SiO_2/TiO_2 nanostructured fibers 认领 引用 被引量：11
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作者 Yu Liu Hongbing Yu +5 位作者 Zhenning Lv Sihui Zhan Jiangyao Yang Xinhong Peng Yixuan Ren Xiaoyan Wu 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2012年第10期1867-1875,共9页
Cerium-doped SiO2/TiO2 nanostructured fibers were fabricated by electrospinning technology. The prepared fibers were characterized by thermogravimetric analysis （TGA）, scanning electron microscopy （SEM）, X-ray dif... Cerium-doped SiO2/TiO2 nanostructured fibers were fabricated by electrospinning technology. The prepared fibers were characterized by thermogravimetric analysis （TGA）, scanning electron microscopy （SEM）, X-ray diffraction （XRD） and Fourier transform infrared spectroscopy （FT-IR）. Using the fibers as catalysts, photoeatalytic degradation of Methylene Blue （MB） aqueous solution was carded out under simulated sunlight. The 0.2% Ce doping proved to be the optimal concentration for the doping of TiO2/SiO2, compared to other Ce-doped molar concentrations. The 0.2% Ce-doped SiOdTiO2 fibers exhibited higher photocatalytic activity than industrial Degussa P25 and the samples doped with only Ce or SIO2. The reasons for improving the photocatalytic activity were also discussed. Several operational parameters were studied, which showed that the photocatalytic efficiency of MB was influenced by parameters such as the initial dye concentration, the initial pH, inorganic anions, and so on. In addition, the influences of an electron acceptor and a radical scavenger suggested that OH was the dominant photooxidant during the photocatalytic process. The reuse evaluation of the fibers indicated that their photocatalytic activity had good stability. 展开更多
关键词 photocatalysis SiO2/TiO2 cerium nanostructured fibers Methylene Blue
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Enhancement of photoluminescence of Ba_2SiO_4:Eu2+ by co-doping of La3+ or Y3+ 认领 引用 被引量：9
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作者 胡小野 李振华 +1 位作者 徐欣 李永绣 《Journal of Rare Earths》 SCIE EI CAS 2009年第1期47-49,共3页
Green light-emitting Ba2SiO4：Eu^2＋ phosphors co-doped with La or Y were synthesized by conventional solid-state reaction technique in reductive atmosphere（a mixture of 5% H2 and 95% N2）.The results showed that the... Green light-emitting Ba2SiO4：Eu^2＋ phosphors co-doped with La or Y were synthesized by conventional solid-state reaction technique in reductive atmosphere（a mixture of 5% H2 and 95% N2）.The results showed that the co-doping of La and Y could greatly enhance the fluorescence intensity of Ba2SiO4：Eu2＋ phosphors.The optimum doping concentration expressed by the x value in（Ba0.985-1.5xREx）2SiO4：0.03Eu^2＋（RE=La or Y） was determined to be of 0.05.The excitation and emission peaks of all as-synthesized phosphors were wide bands.The excitation bands ranged from 250 to 400 nm, which matched well with the wavelength of near ultraviolet white light-emitting diodes（LED） chip and could be used as a potential candidate for the fabrication of white LED.The emission bands from 450 to 550 nm were typical 5d-4f transition emission of Eu^2＋ and displayed un-symmetry profiles because of the two substitution sites of Ba^2＋ with Eu^2＋. 展开更多
关键词 Ba2SiO4：Eu^2＋ phosphor co-doping white light-emitting diodes
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Emission property of Y2O3-doped Mo secondary emitter 认领 引用 被引量：2
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作者 WANG Jin-shu LIU Wei +3 位作者 LI Hong-yi GAO Fei REN Zhi-yuan ZHOU Mei-ling 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS 2010年第2期233-237,共5页
Y2O3-doped Mo secondary emitters were prepared by liquid-liquid doping and solid-solid doping,respectively.The back-scattered scanning observation result indicates that the emitter prepared by liquid-liquid doping has... Y2O3-doped Mo secondary emitters were prepared by liquid-liquid doping and solid-solid doping,respectively.The back-scattered scanning observation result indicates that the emitter prepared by liquid-liquid doping has fine microstructure whereas that prepared by solid-solid doping has large grain size.Y2O3-doped Mo emitter with small grain size prepared by liquid-liquid doping exhibits high emission property,i.e.,the secondary electron yield can get to 5.24,about 1.7 times that prepared by solid-solid doping.Moreover,Y2O3-doped Mo emitter exhibits the best emission performance among La2O3-doped Mo,Y2O3-doped Mo,Gd2O3-doped Mo and Ce2O3-doped Mo emitters due to the largest penetration depth of primary electrons and escape depth of secondary electrons in this emitter.The secondary emission of the emitter with small grain size can be explained by reflection emission model and transmission emission model,whereas only transmission emission exists in the emitter with large grain size. 展开更多
关键词 Y2O3-doped Mo powder metallurgy emission property microstructure
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Engineering of sulfate ions migration in Fe2O3-doped NiSO4/Al2O3 catalysts to enhance the selective trimerization of propylene 认领 引用
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作者 Xu Liu Yu Ling +1 位作者 Xiao Chen Changhai Liang 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2025年第5期376-391,共16页
Propylene,a readily accessible and economically viable light olefin,has garnered substantial interest for its potential conversion into valuable higher olefins through oligomerization processes.The distribution of pro... Propylene,a readily accessible and economically viable light olefin,has garnered substantial interest for its potential conversion into valuable higher olefins through oligomerization processes.The distribution of products is profoundly influenced by the catalyst structure.In this study,Fe2O3-doped NiSO4/Al2O3 catalysts have been meticulously developed to facilitate the selective trimerization of propylene under mild conditions.Significantly,the 0.25Fe2O3-NiSO4/Al2O3 catalyst demonstrates an enhanced reaction rate(48.5 mmolC3/(gcat.·h)),alongside a high yield of C9(~32.2%),significantly surpassing the performance of the NiSO4/Al2O3 catalyst(C9:~24.1%).The incorporation of Fe2O3 modifies the migration process of sulfate ions,altering the Lewis acidity of the electron-deficient Ni and Fe sites on the catalyst and resulting a shift in product distribution from a Schulz-Flory distribution to a Poisson distribution.This shift is primarily ascribed to the heightened energy barrier for theβ-H elimination reaction in the C6 alkyl intermediates on the doped catalyst,further promoting polymerization to yield a greater quantity of Type II C9.Furthermore,the validation of the Cossee-Arlman mechanism within the reaction pathway has been confirmed.It is noteworthy that the 0.25Fe2O3-NiSO4/Al2O3 catalyst exhibits remarkable stability exceeding 80 h in the selective trimerization of propylene.These research findings significantly enhance our understanding of the mechanisms underlying olefin oligomerization reactions and provide invaluable insights for the development of more effective catalysts. 展开更多
关键词 Propylene trimerization Fe2O3-doped NiSO4/Al2O3catalyst Sulfate ions migration Poisson distribution Cossee-Arlman mechanism
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Three-photon-excited fluorescence of Tb3+-doped CaO-Al_2O_3-SiO_2 glass by femtosecond laser irradiation 认领 引用 被引量：3
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作者 马红萍 祝邦文 邹凤楼 《Journal of Rare Earths》 SCIE EI CAS 2008年第6期928-931,共4页
A near infrared to visible blue, green, and red upconversion luminescence in a Tb^3＋-doped CaO-Al2O3-SiO2 glass was studied, which was excited using 800 nm femtosecond laser irradiation. The upconversion luminescence... A near infrared to visible blue, green, and red upconversion luminescence in a Tb^3＋-doped CaO-Al2O3-SiO2 glass was studied, which was excited using 800 nm femtosecond laser irradiation. The upconversion luminescence was attributed to ^5D3→^7F5, ^5D3→^7F4, ^5D3→^7F3, ^5D4→^7F6, ^5D4→^7F5, ^5D4→^7F4, and ^5D4→^7F3 transitions of Tb^3＋. The relationship between upconversion luminescence intensity and the pump power indicated that a three-photon simultaneous absorption process was dominant in this upconversion luminescence. The intense red, green, and blue upconversion luminescence of Tb^3＋-doped CaO-Al2O3-SiO2 glass may be potentially useful in developing three-dimensional display applications. 展开更多
关键词 three-photon-excited fluorescence three-dimensional （3D） volumetric display Tb^3＋-doped CaO-Al2O3-SiO2 glass rare earths
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Effects of annealing temperature and neodymium concentration on structural and photoluminescence properties of Nd3+-doped Y2O3-SiO2 powders 认领 引用 被引量：3
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作者 NoSoung Myoung Gyeong Bok Jung 《Journal of Rare Earths》 SCIE EI CAS CSCD 2021年第6期651-656,I0002,共6页
We report the structural and photoluminescence(PL) properties of Nd3+-doped Y2O3-SiO2 powders(Y2O3-SiO2:Nd3+) as functions of annealing temperature and Nd3+ ion doping concentration.Y2O_(... We report the structural and photoluminescence(PL) properties of Nd3+-doped Y2O3-SiO2 powders(Y2O3-SiO2:Nd3+) as functions of annealing temperature and Nd3+ ion doping concentration.Y2O3-SiO2:Nd3+powders were prepared using the high-energy ball-milling(HEBM) method,and their structural and PL properties were investigated using X-ray diffraction(XRD),Fourier transform infrared(FTIR) spectroscopy,and PL spectroscopy.The XRD results reveal a cubic phase without impurities,and the peak broadening decreases with an increase in annealing temperature due to the increase in the crystallite size.The PL emission intensity increases with an increase in annealing temperature.The highest PL emission intensity is observed for the 300-min milled mixture annealed at 1000℃ for 1 h with a Nd3+ concentration of 1 mol%.The PL peaks excited by 800 nm radiation were detected,centered at 1080 nm(4F3/2→4I11/2) and 1350 nm(4F3/2→4I13/2). 展开更多
关键词 Nd3+-doped Y2O3-SiO2powders High-energy ball-milling method Near infrared photoluminescence emission Rare earth Annealing temperature
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纳米SiO2/钢纤维改性煤矸石地聚物混凝土性能研究 认领 引用 被引量：8
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作者 周彦森 徐钟 +3 位作者 刘兵兵 孙晓静 杨瑞禧 余昊龙 《人民长江》 北大核心 2025年第2期201-208,共8页
为了提高煤矸石地聚物混凝土的力学性能,探索其工程应用潜力,以煤矸石、矿渣为原料制备地聚物混凝土,研究纳米SiO 2(0~2.5%)和钢纤维(0~1.25%)单独及复合掺入对地聚物混凝土力学性能的影响,并用扫描电子显微镜观察了地聚物混凝土的微观... 为了提高煤矸石地聚物混凝土的力学性能,探索其工程应用潜力,以煤矸石、矿渣为原料制备地聚物混凝土,研究纳米SiO 2(0~2.5%)和钢纤维(0~1.25%)单独及复合掺入对地聚物混凝土力学性能的影响,并用扫描电子显微镜观察了地聚物混凝土的微观形貌,分析改性机理。结果表明:适量的钢纤维或纳米SiO 2掺入均能显著提高地聚物混凝土的力学性能,两者混合使用改性效果则更好。在抗压强度方面,纳米SiO 2改性煤矸石混凝土优于钢纤维;在劈裂抗拉和抗折强度方面,钢纤维改性效果更好。纳米SiO 2和钢纤维的复合使用改性效果更好,是由于纳米SiO 2不仅提高了地聚物凝胶的微密度,而且增强了钢纤维与基体之间的结合。研究结果丰富了纳米SiO 2和钢纤维改性地聚物复合材料性能的知识体系,有助于煤矸石地聚物混凝土的进一步推广应用。 展开更多
关键词 地聚物混凝土 钢纤维 纳米SiO 2 微观形貌 改性机理
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SiO2嵌入分离层制备高性能薄膜复合膜 认领 引用 被引量：1
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作者 胡小杰 丰桂珍 +2 位作者 方圳生 张火梅 陈俊 《水处理技术》 CAS CSCD 北大核心 2025年第3期44-48,共5页
为提高传统纳滤膜的分离性与抗污染性,以聚砜超滤膜(PSF)为基膜,以哌嗪(PIP)、均苯三甲酰氯(TMC)分别为水、有机相单体,引入二氧化硅(SiO2)作为水相添加材料,通过界面聚合(IP)反应制备二氧化硅薄膜复合膜(TFN-SiO2),研究SiO2... 为提高传统纳滤膜的分离性与抗污染性,以聚砜超滤膜(PSF)为基膜,以哌嗪(PIP)、均苯三甲酰氯(TMC)分别为水、有机相单体,引入二氧化硅(SiO2)作为水相添加材料,通过界面聚合(IP)反应制备二氧化硅薄膜复合膜(TFN-SiO2),研究SiO2的添加对膜表面特性、分离性能及抗污染性能的影响。结果表明:SiO2的嵌入对膜的表面粗糙度、亲水性和负电性都有较大增强;当SiO2添加质量比为0.02%时,TFN-SiO2膜的水通量达到35.5 L/(m2·h),对Na2SO4的截留维持在95%以上,在30 h的脱盐试验中保持良好的稳定性,同时对腐殖酸(HA)、牛血清蛋白(BSA)、海藻酸钠(SA)三种模型污染物的抗污染性能有所提升。 展开更多
关键词 界面聚合 SiO2 薄膜复合膜 抗污染性
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Enhanced Emission of Eu3+ in Boron Ions-Doped Sol-Gel SiO_2 Phosphors 认领 引用
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作者 Hu Xiaoyun Fan Jun +2 位作者 Bai Jintao Ren Zhaoyu Hou Xun 《Journal of Rare Earths》 SCIE EI CAS 2005年第6期705-705,共1页
Al-doped and B, Al-codoped silica xerogel was fabricated by sol-gel process. The influence of B ions and annealing temperature on luminescent properties of phosphors were studied by using fluorescence spectrum, X-ray ... Al-doped and B, Al-codoped silica xerogel was fabricated by sol-gel process. The influence of B ions and annealing temperature on luminescent properties of phosphors were studied by using fluorescence spectrum, X-ray diffraction, DSC, TG/DTG analysis and IR spectrum. The heat treatment has a large effect on the luminescent properties. Under 248 nm excitation, the emission spectrum of samples heated shows characteristic emission peaks of Eu^3＋ ions are, which are due to the transitions of ^5D0→^7FJ（J = 0, 1, 2, 3, 4） of Eu^3＋ , respectively. The transition of ^5D0→^7F1 is split into two peaks. 展开更多
关键词 Boron ions sol-gel method luminescent properties （Eu^3＋,Eu^2＋,SiO2）xerogel rare earths
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SiO2气凝胶水性保温隔热高温涂料性能研究 认领 引用 被引量：1
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作者 彭战军 韩荣荣 王天赋 《广东化工》 CAS 2025年第15期38-40,31,共3页
本文以SiO2气凝胶作为绝热填料,设计了一种水性保温隔热高温涂料,讨论了配方组成对涂料的稳定性影响,细致研究了SiO2气凝胶添加量和温度对涂料粘结强度、导热系数和耐温性能的影响规律。TG-DSC分析表明SiO2气凝胶水性隔热保温... 本文以SiO2气凝胶作为绝热填料,设计了一种水性保温隔热高温涂料,讨论了配方组成对涂料的稳定性影响,细致研究了SiO2气凝胶添加量和温度对涂料粘结强度、导热系数和耐温性能的影响规律。TG-DSC分析表明SiO2气凝胶水性隔热保温高温涂料,在20℃~500℃升温过程中只有20%的失重,表明涂料具有良好的稳定性,SEM照片和EDS分析表明涂料体系均匀;随着SiO2气凝胶含量的增加,涂料的导热系数降低,但涂料的粘结强度也随之下降;当SiO2气凝胶含量为45%时,涂料的综合性能最佳,常温粘接强度为0.20 Mpa,导热系数为0.036 W·m-1·K-1,500℃时,粘接强度0.1 MPa,导热系数为0.074 W·m-1·K-1。 展开更多
关键词 SiO2气凝胶 隔热保温涂料 高温性能 粘结强度 导热系数
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