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Atomic Ni directional-substitution on ZnIn_(2)S_(4) nanosheet to achieve the equilibrium of elevated redox capacity and efficient carrier-kinetics performance in photocatalysis
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作者 Haibin Huang Guiyang Yu +5 位作者 Xingze Zhao Boce Cui Jinshi Yu Chenyang Zhao Heyuan Liu Xiyou Li 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第1期272-281,I0007,共11页
It is a challenge to coordinate carrier-kinetics performance and the redox capacity of photogenerated charges synchronously at the atomic level for boosting photocatalytic activity.Herein,the atomic Ni was introduced ... It is a challenge to coordinate carrier-kinetics performance and the redox capacity of photogenerated charges synchronously at the atomic level for boosting photocatalytic activity.Herein,the atomic Ni was introduced into the lattice of hexagonal ZnIn_(2)S_(4) nanosheets(Ni/ZnIn_(2)S_(4))via directionalsubstituting Zn atom with the facile hydrothermal method.The electronic structure calculations indicate that the introduction of Ni atom effectively extracts more electrons and acts as active site for subsequent reduction reaction.Besides the optimized light absorption range,the elevation of Efand ECBendows Ni/ZnIn_(2)S_(4) photocatalyst with the increased electron concentration and the enhanced reduction ability for surface reaction.Moreover,ultrafast transient absorption spectroscopy,as well as a series of electrochemical tests,demonstrates that Ni/ZnIn_(2)S_(4) possesses 2.15 times longer lifetime of the excited charge carriers and an order of magnitude increase for carrier mobility and separation efficiency compared with pristine ZnIn_(2)S_(4).These efficient kinetics performances of charge carriers and enhanced redox capacity synergistically boost photocatalytic activity,in which a 3-times higher conversion efficiency of nitrobenzene reduction was achieved upon Ni/ZnIn_(2)S_(4).Our study not only provides in-depth insights into the effect of atomic directional-substitution on the kinetic behavior of photogenerated charges,but also opens an avenue to the synchronous optimization of redox capacity and carrier-kinetics performance for efficient solar energy conversion. 展开更多
关键词 ZnIn_(2)S_(4) substitution Carrier kinetics Redox capacity PHOTOCATALYSIS
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SR9009联合吲哚丙酸通过核因子κB信号通路减轻C2C12成肌细胞的炎症反应
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作者 姬慧慧 蒋旭 +7 位作者 张志敏 邢运虹 王亮亮 李娜 宋雨庭 罗旭光 崔慧林 曹锡梅 《中国组织工程研究》 CAS 北大核心 2025年第6期1220-1229,共10页
背景:钟基因Rev-erbα参与调节炎症,但激活Rev-erbα会增加心脑血管疾病风险。为降低相关风险,探索Rev-erbα激动剂SR9009联合其他药物来减轻骨骼肌成肌细胞炎症,奠定治疗炎症相关性骨骼肌萎缩的理论基础。目的:探讨脂多糖刺激C2C12成... 背景:钟基因Rev-erbα参与调节炎症,但激活Rev-erbα会增加心脑血管疾病风险。为降低相关风险,探索Rev-erbα激动剂SR9009联合其他药物来减轻骨骼肌成肌细胞炎症,奠定治疗炎症相关性骨骼肌萎缩的理论基础。目的:探讨脂多糖刺激C2C12成肌细胞时吲哚丙酸、SR9009与核因子κB信号通路的关系。方法:①1μg/mL脂多糖刺激C2C12成肌细胞,RNA转录组测序结合KEGG通路富集分析信号通路。②CCK-8法检测C2C12成肌细胞活性,筛选吲哚丙酸的最佳给药浓度;然后将细胞分为空白对照组、脂多糖(1μg/mL)组、SR9009(10μmol/L)+脂多糖组、吲哚丙酸(80μmol/L)+脂多糖组、吲哚丙酸+SR9009+脂多糖组,ELISA检测细胞上清液中白细胞介素6水平,RT-qPCR检测白细胞介素6、肿瘤坏死因子α、Toll样受体4、CD14 mRNA表达,Western blot检测NF-κB p65、p-NF-κB p65蛋白表达。③siRNA敲减Rev-erbα,RT-qPCR评估敲减效率,检测白细胞介素6、肿瘤坏死因子αmRNA表达。结果与结论:①与空白对照组比较,脂多糖时间依赖性抑制成肌细胞融合形成肌管,白细胞介素6、肿瘤坏死因子αmRNA表达水平升高,细胞上清液中白细胞介素6水平显著升高;KEGG通路分析支持脂多糖刺激激活核因子κB信号通路。②吲哚丙酸浓度>80μmol/L时抑制C2C12成肌细胞活性;吲哚丙酸和SR9009通过抑制核因子κB信号通路发挥抗炎作用,降低白细胞介素6、肿瘤坏死因子α、Toll样受体4、CD14 mRNA表达水平,p-NF-κB p65/NF-κB p65蛋白表达比值低于脂多糖组。SR9009联合吲哚丙酸显著降低脂多糖诱导的炎症,Toll样受体4、CD14、白细胞介素6和肿瘤坏死因子αmRNA表达水平进一步下调,p-NF-κB p65/NF-κB p65蛋白表达比值显著低于吲哚丙酸+脂多糖组和SR9009+脂多糖组。③Rev-erbα随脂多糖刺激时间依赖性升高;siRNA敲减Rev-erbα效率达58%以上,成功敲减Rev-erbα后添加脂多糖,白细胞介素6和肿瘤坏死因子αmRNA表达较脂多糖组显著上调。④结果说明,Rev-erbα可以作为调节炎症反应的靶点,SR9009靶向激活Rev-erbα联合吲哚丙酸能抑制核因子κB信号通路显著减轻C2C12成肌细胞的炎症反应,联合抗炎效果优于单独干预。 展开更多
关键词 Rev-erbα sr9009 吲哚丙酸 脂多糖 核因子ΚB信号通路 C2C12成肌细胞
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湖南省新田县富锶岩溶水矿物饱和指数特征,Sr^(2+)、SO_(4)^(2-)来源及开发潜力
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作者 赵光帅 苏春田 +4 位作者 黄奇波 朱义年 杨杨 罗飞 李小盼 《中国地质》 CAS CSCD 北大核心 2024年第3期1046-1058,共13页
【研究目的】湖南新田县发现大型富锶矿泉水田,然而锶元素来源及锶矿泉开发利用潜力研究相对薄弱,此外探究富锶岩溶水水化学特征及锶元素来源可为岩溶区寻找富锶地下水提供一定的理论支撑。【研究方法】通过开展水文地质调查,富锶地下... 【研究目的】湖南新田县发现大型富锶矿泉水田,然而锶元素来源及锶矿泉开发利用潜力研究相对薄弱,此外探究富锶岩溶水水化学特征及锶元素来源可为岩溶区寻找富锶地下水提供一定的理论支撑。【研究方法】通过开展水文地质调查,富锶地下水水化学指标检测分析,利用PHREEQC软件、水化学计量法、端元法、水文地质参数等揭示富锶岩溶水矿物饱和指数特征,Sr^(2+)、SO_(4)^(2-)来源及富锶地下水开发潜力。【研究结果】方解石在下降泉和机井中均主要处于饱和状态,白云石由下降泉中未饱和状态转为机井中的饱和状态,菱锶矿在机井中出现饱和状态,石膏在下降泉和机井中均为未饱和状态。下降泉中矿物饱和指数随泉水溶解性总固体增加而升高,两者呈较好的正相关关系,但在机井中两者相关性较差。下降泉SO_(4)^(2-)和大气降水SO_(4)^(2-)具有较好的拟合关系,根据Ca^(2+)、Mg^(2+)、Sr^(2+)、HCO_(3)^(-)、SO_(4)^(2-)化学计量关系,机井中SO_(4)^(2-)可能来源于石膏溶解。下降泉中Sr^(2+)主要来源于石灰岩中以类质同像置换钙的锶,机井中Sr^(2+)较大可能来源于含水层中菱锶矿。研究区85.2%水点的地下水符合国家生活饮用水卫生标准,超标水点多为单指标超标。经计算,枯水年富锶地下水天然补给资源量、可开采资源量和地下水资源潜力分别为3.83×10^(7)m^(3)/a、1.05×10^(7)m^(3)/a、7.28×10^(6)m^(3)/a。【结论】新田县富锶地下水中锶主要来源于泥盆系佘田桥组地层含锶矿物(类质同像置换钙的锶和菱锶矿)的溶解,富锶地下水资源量及资源潜力可观,具有较大的开发利用潜力与价值。 展开更多
关键词 富锶岩溶水 矿物饱和指数 sr^(2+)和SO_(4)^(2-) 开发潜力 水文地质调查工程 新田县 湖南省
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Ca and Sr co-doping induced oxygen vacancies in 3DOM La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)catalysts for boosting low-temperature oxidative coupling of methane
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作者 Tongtong Wu Yuechang Wei +5 位作者 Jing Xiong Yitao Yang Zhenpeng Wang Dawei Han Zhen Zhao Jian Liu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第4期331-344,共14页
It is urgent to develop catalysts with application potential for oxidative coupling of methane(OCM)at relatively lower temperature.Herein,three-dimensional ordered macro porous(3 DOM)La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)(... It is urgent to develop catalysts with application potential for oxidative coupling of methane(OCM)at relatively lower temperature.Herein,three-dimensional ordered macro porous(3 DOM)La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)(A_(2)B_(2)O_(7)-type)catalysts with disordered defective cubic fluorite phased structure were successfully prepared by a colloidal crystal template method.3DOM structure promotes the accessibility of the gaseous reactants(O2and CH4)to the active sites.The co-doping of Ca and Sr ions in La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)catalysts improved the formation of oxygen vacancies,thereby leading to increased density of surface-active oxygen species(O_(2)^(-))for the activation of CH4and the formation of C2products(C2H6and C2H4).3DOM La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)catalysts exhibit high catalytic activity for OCM at low temperature.3DOM La1.7Sr0.3Ce1.7Ca0.3O7-δcatalyst with the highest density of O_(2)^(-)species exhibited the highest catalytic activity for low-temperature OCM,i.e.,its CH4conversion,selectivity and yield of C2products at 650℃are 32.2%,66.1%and 21.3%,respectively.The mechanism was proposed that the increase in surface oxygen vacancies induced by the co-doping of Ca and Sr ions boosts the key step of C-H bond breaking and C-C bond coupling in catalyzing low-temperature OCM.It is meaningful for the development of the low-temperature and high-efficient catalysts for OCM reaction in practical application. 展开更多
关键词 3DOM catalysts Ca ions sr ions Low-temperature oxidative couplingof methane Oxygen vacancies O_(2)^(-) species
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Influence of CaxSr1-x(0≤x≤1)Substitution for Zn on Microwave Dielectric Properties of Li2ZnTi3O8 Ceramic as Temperature Stable Materials 被引量:1
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作者 田仕 LIAO Zelin +1 位作者 WANG Heng 王为民 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2020年第4期686-690,共5页
A temperature stable Li2Zn0.95(SrxCa1-x)0.05Ti3O8(0≤x≤1)ceramics were fabricated using a conventional solid-state route sintered at 1100℃for 4 h.The XRD results indicate that the main phase Li2ZnTi3O8 and secondary... A temperature stable Li2Zn0.95(SrxCa1-x)0.05Ti3O8(0≤x≤1)ceramics were fabricated using a conventional solid-state route sintered at 1100℃for 4 h.The XRD results indicate that the main phase Li2ZnTi3O8 and secondary phase including SrxCa1-xTiO3(0≤x≤1)solid solution and TiO2 co-exist in composite and form a stable composite system when the(CaxSr1-x)(0≤x≤1)substitutes for Zn of Li2ZnTi3O8 ceramic.As x is increased from 0 to 1,the relative permittivity(εr)increases from 26.65 to 27.12,and the quality factor(Q×f)increases from 63300 to 66600 GHz.With the increased of x,the temperature coefficient of resonant frequency(τf)increases from 0.27 to 8.23 ppm/℃,and then decreases to 3.51 ppm/℃.On the whole,the Li2Zn0.95(SrxCa1-x)0.05Ti3O8(0≤x≤1)ceramics show excellent comprehensive properties of middleεr=25-27,higher Q×f≥60000 GHz andτf≤±8.5 ppm/℃. 展开更多
关键词 Li2Zn0.95(srxCa1-x)0.05Ti3O8(0≤x≤1) microwave dielectric properties temperature stable materials substitution
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蒙脱石-碳酸盐矿化菌对Sr^(2+)的联合去除作用研究 被引量:1
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作者 代群威 王维富 +3 位作者 赵玉连 许凤琴 党政 王岩 《原子能科学技术》 EI CAS CSCD 北大核心 2023年第3期485-492,共8页
通过构建蒙脱石-碳酸盐矿化菌复合体系,研究了黏土矿物与微生物对Sr^(2+)的联合去除作用特征。结果表明,蒙脱石与碳酸盐矿化菌分别能通过吸附、微生物矿化等作用实现对Sr^(2+)的去除;Sr^(2+)的去除率与蒙脱石投加量呈正比,复合体系中两... 通过构建蒙脱石-碳酸盐矿化菌复合体系,研究了黏土矿物与微生物对Sr^(2+)的联合去除作用特征。结果表明,蒙脱石与碳酸盐矿化菌分别能通过吸附、微生物矿化等作用实现对Sr^(2+)的去除;Sr^(2+)的去除率与蒙脱石投加量呈正比,复合体系中两者在不同时间的作用效果不同,蒙脱石对Sr^(2+)的吸附作用随时间的增加而降低,而碳酸盐矿化菌对其矿化率随时间的增加而升高;在初始Sr^(2+)浓度为1100.19 mg/L条件下,蒙脱石投加量为40 g/L的单一体系对Sr^(2+)的最高去除率仅为28.48%,蒙脱石-碳酸盐矿化菌复合体系对Sr^(2+)的去除率高达97.92%。因此,构建的蒙脱石-碳酸盐矿化菌体系能有效实现Sr^(2+)的高效去除。 展开更多
关键词 蒙脱石 碳酸盐矿化菌 sr^(2+) 吸附 微生物矿化
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Effect of Substitution Sr Cations on the Structure in the Gd_(1)(Ba_(2−x)Sr_(x))Cu_(3)O_(7−δ) Phases
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作者 Made Sumadiyasa Nyoman Wendri +1 位作者 Putu Suardana Ni Nyoman Rupiasih 《Journal of Materials Science and Chemical Engineering》 2020年第1期44-53,共10页
In an effort to improve the performance of superconductors in the field and high temperatures it is important to study the superconducting mechanism. For this reason, the cation substitution can be conducted. One of t... In an effort to improve the performance of superconductors in the field and high temperatures it is important to study the superconducting mechanism. For this reason, the cation substitution can be conducted. One of the high Tc superconductors Gd1Ba2Cu3O7&minus;δ phase with Sr substitution has been synthesized, i.e. Gd1(Ba2&minus;xSrx)Cu3O7&minus;δ compound. The sample was synthesized by using a solid-state reaction method with a wet mixing, sintered for 12 hours at temperature 900°C. The synthesis results are characterized by using XRD. The results of Match-3 software analysis showed high (higher 85%) Gd1Ba2Cu3O7&minus;δ phase was formed. The Sr substitution causes changes to the structure, i.e. the lattice parameters a, b and c, where the orthorhombicity tends to decrease with increasing Sr content. Refinement results show that based on the oxygen occupancy, the total oxygen content tends to increase. 展开更多
关键词 Wet Mixing Gd_(1)(Ba_(2-x)sr_(x))Cu_(3)O_(7-δ) Compound sr substitution Lattice Parameters Orthorhombicity
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蒙脱石-脱氮硫杆菌体系对Sr^(2+)的去除能力
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作者 代群威 利勇 +2 位作者 邬琴琴 赵玉连 王维富 《核化学与放射化学》 CAS CSCD 北大核心 2023年第6期557-562,I0004,共7页
放射性核素的污染对人类环境危害极大,研究其可行的治理方法具有重要意义,关于微生物与矿物结合去除Sr^(2+)的研究较少。本实验将前期筛选的脱氮硫杆菌与蒙脱石构建菌-矿体系,利用液相离子色谱、多功能X射线衍射仪(XRD)、扫描电镜(SEM)... 放射性核素的污染对人类环境危害极大,研究其可行的治理方法具有重要意义,关于微生物与矿物结合去除Sr^(2+)的研究较少。本实验将前期筛选的脱氮硫杆菌与蒙脱石构建菌-矿体系,利用液相离子色谱、多功能X射线衍射仪(XRD)、扫描电镜(SEM)等方法表征体系中pH、SO_(4)^(2-)的变化和蒙脱石-脱氮硫杆菌体系(Mont-TD)对溶液中Sr^(2+)的去除能力和固化能力。结果显示,Mont-TD体系对Sr^(2+)有较高的去除效果,在Sr^(2+)质量浓度为1000 mg/L、150 mL的培养基中加入6 g蒙脱石、体积比1∶100的菌液,30 d后,Sr^(2+)去除率达到93.2%,固化率达到71.1%,产物中产生SrSO_(4)晶体。通过构建Mont-TD体系,实现了对溶液中Sr^(2+)的有效去除,部分Sr^(2+)被稳定固化,蒙脱石-脱氮硫杆菌体系可为治理环境中锶离子污染提供一种思路。 展开更多
关键词 蒙脱石 脱氮硫杆菌 sr^(2+) 固化率
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Sr^(2+) 在阳江花岗岩上的吸附行为
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作者 蒋巧 王彦惠 +7 位作者 成建峰 潘跃龙 洪涛 包晨阳 刘羽 冷阳春 王李涛 庹先国 《核化学与放射化学》 CAS CSCD 北大核心 2023年第3期250-258,I0004,共10页
以阳江中低放核废物处置库围岩花岗岩为研究对象,通过静态吸附实验探究了阳江花岗岩围岩吸附Sr^(2+)的行为,详细研究了接触时间、初始浓度、反应温度、pH值、阴阳离子对花岗岩吸附行为的影响,并通过表征手段研究了阳江花岗岩的物化组成... 以阳江中低放核废物处置库围岩花岗岩为研究对象,通过静态吸附实验探究了阳江花岗岩围岩吸附Sr^(2+)的行为,详细研究了接触时间、初始浓度、反应温度、pH值、阴阳离子对花岗岩吸附行为的影响,并通过表征手段研究了阳江花岗岩的物化组成。结果表明:阳江花岗岩是一种主要由硅氧化物构成的岩石,吸附后其表面变得粗糙。吸附在5 d达到吸附平衡,属于化学吸附行为。吸附和Langmuir等温模型拟合效果更好,Sr^(2+)更多吸附在阳江花岗岩的表面。酸性和碱性环境均会削弱阳江花岗岩对Sr^(2+)的吸附能力,且升高温度和增大初始浓度均有利于吸附。地下水中存在的Ca^(2+)、Mg^(2+)、Fe^(3+)、NO_(3)^(-)均会抑制阳江花岗岩对Sr^(2+)的吸附,CO_(2)-3会和Sr^(2+)生成聚合物而干扰吸附。此研究可以为阳江中低放核废物处置库的安全评估提供一定参考。 展开更多
关键词 sr^(2+) 阳江花岗岩 中低放核废物处置库 吸附行为
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电场辅助α-磷酸锆/氧化石墨烯复合材料吸附Sr^(2+)
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作者 汪媛 杨沛霖 +3 位作者 赵茂杰 唐维汕 何平 董发勤 《化工环保》 CAS CSCD 北大核心 2023年第3期331-338,共8页
采用水热法制备了α-磷酸锆(α-ZrP)/氧化石墨烯(GO)纳米复合材料,采用XRD、SEM、EDX、FTIR和XPS对其进行了表征,并将其制成电极,考察了其在电场辅助下对Sr^(2+)的吸附性能。表征结果显示,纳米片状的α-ZrP在具有大比表面积的GO表面生长... 采用水热法制备了α-磷酸锆(α-ZrP)/氧化石墨烯(GO)纳米复合材料,采用XRD、SEM、EDX、FTIR和XPS对其进行了表征,并将其制成电极,考察了其在电场辅助下对Sr^(2+)的吸附性能。表征结果显示,纳米片状的α-ZrP在具有大比表面积的GO表面生长,团聚现象减少。实验结果表明:在α-ZrP与GO质量比9∶1、外加电压1.2 V、溶液pH 7.0的条件下,采用α-ZrP/GO吸附50 mg/L SrCl2溶液120 min,Sr^(2+)吸附量可达45.28 mg/g,高于纯α-ZrP和GO,约为无电场吸附时的2倍;α-ZrP/GO具有良好的稳定性,可循环使用,5次循环后的Sr^(2+)吸附量仍保持原吸附量的88%;α-ZrP/GO对Sr^(2+)的吸附符合准二级动力学模型和Langmuir等温吸附模型,吸附过程以离子交换反应的化学吸附为主,存在单层吸附。 展开更多
关键词 sr^(2+) 吸附 电场辅助 磷酸锆 氧化石墨烯 解吸
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阳离子替换提升Li_(3)Cs_(2)Ba_(2-x)Sr_(x)B_(3)P_6O_(24)∶Eu^(2+)荧光粉热稳定性 被引量:1
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作者 索慧娴 宋志 +3 位作者 康晓娇 李昕明 周飞 吕伟 《发光学报》 EI CAS CSCD 北大核心 2023年第5期837-844,共8页
热猝灭性能极大程度上限制了发光材料的应用,如何改善发光材料的热稳定性这一课题受到了广泛关注。本文通过高温固相法制备了一系列浓度梯度的Li_(3)Cs_(2)Ba_(2-x)Sr_(x)B_(3)P_(6)O_(24)∶0.03Eu^(2+)荧光粉,并对该系列荧光粉进行了表... 热猝灭性能极大程度上限制了发光材料的应用,如何改善发光材料的热稳定性这一课题受到了广泛关注。本文通过高温固相法制备了一系列浓度梯度的Li_(3)Cs_(2)Ba_(2-x)Sr_(x)B_(3)P_(6)O_(24)∶0.03Eu^(2+)荧光粉,并对该系列荧光粉进行了表征,对其XRD、激发发射光谱、荧光寿命、热猝灭性能进行了分析。结果表明,通过阳离子Sr替代Ba的方法不但改善了晶格结构,提升了样品的发光强度,而且使原发光材料的热稳定性能进一步得到了提高。对于Li_(3)Cs_(2)Ba_(2)B_(3)P_(6)O_(24)∶Eu^(2+)样品,在150℃下的发光强度已经可以达到常温下的79%,通过Sr替换Ba,该强度能够进一步提高到87%。相关分析及结论可为荧光粉热稳定性的改善提供思路与依据。 展开更多
关键词 荧光粉 Eu^(2+)掺杂 温度猝灭 阳离子替换
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新型橙红色荧光粉Sr_(3)CaNb_(2)O_(9)∶Sm^(3+)的制备及发光性能研究
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作者 肖泽宇 沈汉鑫 +3 位作者 孟宪国 刘月 范浩爽 洪俊煌 《化工新型材料》 CAS CSCD 北大核心 2023年第S02期289-295,共7页
通过高温固相法制备了一系列Sr_(3)CaNb_(2)O_(9)∶xSm^(3+)(0.04≤x≤0.1)新型橙红色荧光粉。研究了其物相、形貌、发光性能、热稳定性和CIE色度坐标。X射线衍射(XRD)物相分析和Rietveld精修结果表明合成了Sr_(3)CaNb_(2)O_(9)的纯相。... 通过高温固相法制备了一系列Sr_(3)CaNb_(2)O_(9)∶xSm^(3+)(0.04≤x≤0.1)新型橙红色荧光粉。研究了其物相、形貌、发光性能、热稳定性和CIE色度坐标。X射线衍射(XRD)物相分析和Rietveld精修结果表明合成了Sr_(3)CaNb_(2)O_(9)的纯相。在407nm的紫光激发下,Sr_(3)CaNb_(2)O_(9)∶Sm^(3+)在645nm处发红光,可归因于Sm^(3+)的^(4)G_(5/2)→^(6)H_(9/2)跃迁。实验表明Sr_(3)CaNb_(2)O_(9)∶xSm^(3+)的最佳掺杂浓度为x=0.07,根据Dexter理论分析,其浓度猝灭机理为电偶极-电偶极相互作用。Sr_(3)CaNb_(2)O_(9)∶Sm^(3+)在423K下发光强度是室温下的90.3%,表现出良好的热稳定性。Sr_(3)CaNb_(2)O_(9)∶xSm^(3+)的发光色坐标均位于橙红色区域,且具有较高的色纯度。结果表明Sr_(3)CaNb_(2)O_(9)∶Sm^(3+)荧光粉在白光发光二极管(WLED)中具有潜在的应用前景。 展开更多
关键词 sr3CaNb2O9∶Sm3+ 高温固相法 光谱分析
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低介电损耗Ca_(1-x)Sr_(x)MgSi_(2)O_(6)微波介质陶瓷的结构和介电性能
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作者 章国涛 高艳 +3 位作者 刘书利 孟德喜 高娜燕 郑勇 《材料导报》 EI CAS CSCD 北大核心 2023年第4期68-72,共5页
本工作研究了Sr^(2+)取代Ca^(2+)对Ca_(1-x)Sr_(x)MgSi_(2)O_(6)陶瓷烧结特性、物相组成、显微组织和微波介电性能的影响。结果表明:采用Sr^(2+)取代部分Ca^(2+)时可以降低陶瓷的烧结温度,并且提高陶瓷的致密度。当Sr^(2+)取代量小于等... 本工作研究了Sr^(2+)取代Ca^(2+)对Ca_(1-x)Sr_(x)MgSi_(2)O_(6)陶瓷烧结特性、物相组成、显微组织和微波介电性能的影响。结果表明:采用Sr^(2+)取代部分Ca^(2+)时可以降低陶瓷的烧结温度,并且提高陶瓷的致密度。当Sr^(2+)取代量小于等于0.5时,陶瓷烧结体中只存在单一的CaMgSi_(2)O_(6)相。随着Sr^(2+)取代量的增加,Ca_(1-x)Sr_(x)MgSi_(2)O_(6)陶瓷的介电常数和品质因数均先增大后减小,而谐振频率温度系数逐渐增大。当Sr^(2+)取代量为0.4时,Ca_(0.6)Sr_(0.4)MgSi_(2)O_(6)陶瓷在1225℃下烧结4 h具有较佳的综合微波介电性能:ε_(r)=7.480,Q×f=78920 GHz,τ_(f)=-41.50×10^(-6)/℃。 展开更多
关键词 微波介质陶瓷 CaMgSi_(2)O_(6) 离子取代 介电性能
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区域选择性O-烯丙基取代反应合成2-吡啶酮衍生物
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作者 李璐 赵盟林 +3 位作者 李娜 袁明伟 袁明龙 蒋琳 《云南大学学报(自然科学版)》 CAS CSCD 北大核心 2024年第1期166-172,共7页
报道了一种有机催化合成2-吡啶酮衍生物的方法.以N-取代的3-羟基-2-吡啶酮和Morita-Baylis-Hillman(MBH)碳酸酯为原料,在亲核性有机胺催化下,经区域选择性O-烯丙基取代反应合成一系列含有2-吡啶酮片段的多官能团产物,产率51%~91%.在温... 报道了一种有机催化合成2-吡啶酮衍生物的方法.以N-取代的3-羟基-2-吡啶酮和Morita-Baylis-Hillman(MBH)碳酸酯为原料,在亲核性有机胺催化下,经区域选择性O-烯丙基取代反应合成一系列含有2-吡啶酮片段的多官能团产物,产率51%~91%.在温和的反应条件下实现了3-羟基-2-吡啶酮类化合物的羟基功能化. 展开更多
关键词 3-羟基-2-吡啶酮 MBH碳酸酯 胺催化 烯丙基取代 区域选择性
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Li(Sc,M)Si_(2)O_(6)∶Cr^(3+)(M=Ga^(3+)/Lu^(3+)/Y^(3+)/Gd^(3+))的近红外发光性能
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作者 卢紫微 刘永福 +2 位作者 罗朝华 孙鹏 蒋俊 《发光学报》 EI CAS CSCD 北大核心 2024年第3期407-414,共8页
荧光转换型近红外发光二极管(NIR pc-LED)具有体积小、谱带宽、峰位易调谐等优点,是新一代NIR光源发展的前沿,其关键在于研发可被蓝光有效激发的高效率宽带近红外荧光粉。LiScSi_(2)O_(6)∶Cr^(3+)荧光材料的激发波长为460 nm,发射峰位... 荧光转换型近红外发光二极管(NIR pc-LED)具有体积小、谱带宽、峰位易调谐等优点,是新一代NIR光源发展的前沿,其关键在于研发可被蓝光有效激发的高效率宽带近红外荧光粉。LiScSi_(2)O_(6)∶Cr^(3+)荧光材料的激发波长为460 nm,发射峰位在845 nm,光谱带宽为156 nm,内量子效率为64.4%。基于该体系,本文通过M离子(M=Ga^(3+),Lu^(3+),Y^(3+),Gd^(3+))取代Sc^(3+)的方式对其性能进行调控。结果表明,引入M离子易生成杂相或发生相变,降低了材料的发光性能。本文从晶体结构出发对其调控过程进行了分析。 展开更多
关键词 LiScSi_(2)O_(6)∶Cr^(3+) 阳离子取代 晶体结构
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The magnetic and dielectric properties of multiferroic Sr-substituted Zn_2-Y hexagonal ferrites 被引量:1
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作者 徐芳 白洋 +1 位作者 艾芬 乔利杰 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第12期4652-4655,共4页
The magnetic and dielectric properties of Sr-substituted Zn2-Y hexagonal ferrites (Ba2-x SrxZn2Fe12O22, 1.0 〈 x ≤ 1.5) are studied in this paper. Sr substitution will lead to the variation of cation occupation, wh... The magnetic and dielectric properties of Sr-substituted Zn2-Y hexagonal ferrites (Ba2-x SrxZn2Fe12O22, 1.0 〈 x ≤ 1.5) are studied in this paper. Sr substitution will lead to the variation of cation occupation, which influences both the magnetic and electric properties. As Sr content x rises from 1.0 to 1.5, magnetic hysteresis loop gets wider gradually and the permeability drops rapidly due to the transformation from ferrimagnetic to antiferromagnetic phase. Moreover, permittivity rises with increasing Sr content. Under a certain external magnetic field, the phase transition of helical spin structure of Ba0.5Srl.5Zn2Fe12O22 at about 295 K seems to open a possibility for the room-temperature ferroelectricity induced by magnetic field. But its low resistivity prevents the observation of ferroelectric and magnetoelectric properties at room-temperature. 展开更多
关键词 hexagonal ferrite sr substitution MULTIFERROIC POLYCRYSTAL
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Effect of erbium substitution on thermoelectric properties of complex oxide Ca_3Co_2O_6 at high temperatures 被引量:2
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作者 陆冬青 陈刚 +2 位作者 裴健 杨曦 线恒泽 《Journal of Rare Earths》 SCIE EI CAS CSCD 2008年第2期168-172,共5页
Polycrystalline particles of Ca3-xErxCo2O6 (x=0.0, 0.15, 0.3, 0.45 and 0.6) were synthesized using sol-gel method combined with Low Temperature Sintering procedure (LTS) to evaluate the effect of Er substitution o... Polycrystalline particles of Ca3-xErxCo2O6 (x=0.0, 0.15, 0.3, 0.45 and 0.6) were synthesized using sol-gel method combined with Low Temperature Sintering procedure (LTS) to evaluate the effect of Er substitution on the thermoelectric properties of Ca3Co2O6. The crystal structure and microstructure were investigated using X-ray diffraction, infrared spectroscopy and scanning electron microscope. The electrical conductivity and Seebeck coefficient of the complex oxides were measured from 300 to 1073 K. The results showed that all the sampies were p-type semiconductors. The electrical conductivity increased with the increase in temperature. Er substitutions at Ca site affected carrier concentrations and carder mobility, resulting an increase in Seebeck coefficient and decrease in electrical conductivity. The power factor of Ca2.85Er0.15Co2O6 reached 10.66 μw/mK^2 at 1073 K. 展开更多
关键词 Ca3Co2O6 thermoelectric properties rare earth substitution cobalt oxide rare earths
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A flexible design strategy to modify Ti3C2Tx MXene surface terminations via nucleophilic substitution for long-life Li-S batteries 被引量:2
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作者 Tianpeng Zhang Wenlong Shao +5 位作者 Siyang Liu Zihui Song Runyue Mao Xin Jin Xigao Jian Fangyuan Hu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2022年第11期349-358,I0010,共11页
MXene-based materials have gained considerable attention for lithium-sulfur(Li-S)batteries cathode materials due to their superior electric conductivity and high affinitive to polysulfides.However,there are still chal... MXene-based materials have gained considerable attention for lithium-sulfur(Li-S)batteries cathode materials due to their superior electric conductivity and high affinitive to polysulfides.However,there are still challenges in modifying the surface functional groups of MXene to further improve the electrochemical performance and increase the structure variety for MXene-based sulfur host.Herein,we report an efficient and flexible nucleophilic substitution(S_(N))strategy to modify the Ti_(3)C_(2)T_(x) surface terminations and purposefully designed Magnolol-modified Ti_(3)C_(2)T_(x)(M-Ti_(3)C_(2)T_(x))as powerful cathode host materials.Benefiting from more C-Ti-O bonds forming and diallyl groups terminations reducing after the dehalogenation and nucleophilic addition reactions,the given M-Ti_(3)C_(2)T_(x) electrode could effectively suppress the lithium polysulfides shuttling via chemisorption and C—S covalent bond formation.Besides,the Magnolol-modified Ti_(3)C_(2)T_(x) significantly accelerates polysulfide redox reaction and reduces the activation energy of Li_(2) S decomposition.As a result,the as-prepared M-Ti_(3)C_(2)T_(x) electrode displays an excellent rate capability and a high reversible capacity of 7.68 mAh cm^(-2)even under 7.2 mg cm^(-2)S-loaded with a low decay rate of 0.07%(from 2 nd cycle).This flexible surface-modified strategy for MXene terminations is expected to be extended to other diverse MXene applications. 展开更多
关键词 Lithium-sulfur batteries Nucleophilic substitution Magnolol-modified Ti3C2Tx Multifunctional sulfur host Long-cycle life
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Surface defect ordered Cu_(2)ZnSn(S,Se)_(4) solar cells with efficiency over 12% via manipulating local substitution 被引量:5
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作者 Changcheng Cui Dongxing Kou +5 位作者 Wenhui Zhou Zhengji Zhou Shengjie Yuan Yafang Qi Zhi Zheng Sixin Wu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2022年第4期555-562,共8页
The environmentally friendly Cu_(2)ZnSn(S,Se)_(4)(CZTSSe) compounds are promising direct bandgap materials for application in thin film solar cells, but the spontaneous surface defects disordering would lead to large ... The environmentally friendly Cu_(2)ZnSn(S,Se)_(4)(CZTSSe) compounds are promising direct bandgap materials for application in thin film solar cells, but the spontaneous surface defects disordering would lead to large open-circuit voltage deficit(V_(oc,deficit)) and significantly limit kesterite photovoltaics performance,primarily arising from the generated more recombination centers and insufficient p to n conversion at p-n junction. Herein, we establish a surface defects ordering structure in CZTSSe system via local substitution of Cu by Ag to suppress disordered Cu_(Zn) defects and generate benign n-type Zn_(Ag) donors. Taking advantage of the decreased annealing temperature of Ag F post deposition treatment(PDT), the high concentration of Ag incorporated into surface absorber facilitates the formation of surface ordered defect environment similar to that of efficient CIGS PV. The manipulation of highly doped surface structure could effectively reduce recombination centers, increase depletion region width and enlarge the band bending near p-n junction. As a result, the Ag F-PDT device finally achieves maximum efficiency of 12.34% with enhanced V_(oc) of 0.496 V. These results offer a new solution route in surface defects and energy-level engineering, and open the way to build up high quality p-n junction for future development of kesterite technology. 展开更多
关键词 KESTERITE Cu_(2)ZnSn(S Se)_(4)thin film solar cells Interface recombination Defect passivation Ag substitution
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Effect of Strontium Substitution on Microstructure and Magnetic Properties of Electrospinning BaFe12O19 Nanofibers 被引量:1
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作者 侯传信 LIU Guifang +2 位作者 党锋 ZHANG Zidong CHEN Ju 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2017年第4期871-874,共4页
Barium ferrite micro/nano fibers were successfully prepared via the electrostatic spinning by using dimethyl formamide(DMF) as the solvent, and poly vinyl pyrrolidone(PVP) as the spinning auxiliaries. Effects of s... Barium ferrite micro/nano fibers were successfully prepared via the electrostatic spinning by using dimethyl formamide(DMF) as the solvent, and poly vinyl pyrrolidone(PVP) as the spinning auxiliaries. Effects of strontium substitution on the structure, morphology, and magnetic properties were investigated by scanning electron microscope(SEM), X-ray diffraction analysis(XRD), and vibration sample magnetometer(VSM). XRD patterns of the samples confirm that pure barium ferrite fibers form, and the Sr substitution makes the main peaks(110),(107), and(114) move to right slightly. Also, the FE-SEM images show that the Sr substituted fibers can keep complete fibrous morphology. Moreover, the VSM results demonstrate that the saturation magnetization can reach 56.7 emu/g when the fibers are calcined at 800℃. 展开更多
关键词 electrostatic spinning sr substituted barium ferrite fibers magnetic properties
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