Tunable BaxSr1-xTiO3 nanoparticles induced high energy storage density in layer-structured asymmetric polymer-based nanocomposites

In order to solve the problem of low charging and discharging energy density of dielectric capacitors, the structure design of layered polymer matrix composites is carried out in this paper. Ba_0.7Sr_0.3TiO₃, Ba_0.8Sr_0.2TiO₃ and Ba_0.9Sr_0.1TiO₃ nanoparticles were successfully prepared by the oxalate coprecipitation method. The surface of Ba_xSr_1-xTiO₃ was successfully coated with dopamine, which promoted the dispersion of the polymer matrix of the ceramic powder. Monolayer Ba_xSr_1-xTiO₃/PVDF composites containing Ba_xSr_1-xTiO₃ with different Ba/Sr ratios were successfully prepared by the casting method. Three-layer asymmetric composites with different fillers were successfully prepared by layer-by-layer casting. The phase and microstructure of the as-prepared materials were analyzed by XRD and SEM. The dielectric, electrical conductivity, ferroelectric and energy storage properties of the composites were tested. The effects and laws of the design of the three-layer asymmetric structure on the dielectric properties and energy storage properties of the layered composites are mainly studied. When the structure of the three-layer asymmetric composite is 1-2-3, the breakdown field strength reaches 330 kV/mm, the discharge energy density reaches 8.51 J/cm³, and the charge-discharge efficiency is 67%. This work demonstrates that layered composites with asymmetric properties can facilitate the development of electrical energy storage.     

红色烟火着色剂MOF[Sr2(DTDA)(H2O)6]n的制备与性能

以富氮羧酸类分子2,2'-(3,3'-偶氮-双(1H-1,2,4-三唑-5基))二乙酸(H2DTDA)与氢氧化锶八水合物为原料,在水热条件下制备了一种金属有机框架(MOF)结构的新型红色烟火着色剂[Sr_2(DTDA)(H_2O)_6]_n(1);采用傅里叶变换红外光谱(FT-IR)、X射线单晶衍射(XRD)、粉末X射线单晶衍射(PXRD)和元素分析等对化合物结构进行了表征;采用热重法(TG)-差示扫描量热法(DSC)、BAM标准法测试了化合物1的热性能和感度性能;设计了烟火剂配方,对化合物1应用于红色烟火着色剂的可行性进行分析。结果表明,化合物1是一种具有二维空间结构的MOF材料,其层状结构之间存在丰富的氢键作用;放大合成的水热实验同样可以得到高纯度的化合物1;撞击感度为80 J,摩擦感度 360 N;化合物1可作为红色着色剂应用于烟火剂配方中。     

基于锶元素含量及其稳定同位素比值的库尔勒香梨产地鉴别

开展锶（Sr）元素含量及其稳定同位素比值鉴别库尔勒香梨产地的可行性研究，明确新疆库尔勒香梨87Sr/86Sr同位素特征值，为库尔勒香梨产地真实性鉴别提供科学依据。以陕西红香酥梨和甘肃香梨作为对照，借助电感耦合等离子质谱分析新疆库尔勒香梨与对照样品及其对应果园土壤的Sr元素含量，采用多接收器电感耦合等离子质谱分析库尔勒香梨果皮与果肉87Sr/86Sr同位素比值。通过方差分析比较不同产地、不同年际土壤及果实中Sr元素含量的差异，探讨果实与土壤Sr元素含量的相关关系，以及不同产地果实87Sr/86Sr同位素比值与Sr元素含量的分布特征。结果表明：新疆、甘肃、陕西共3 个产地梨园土壤Sr含量存在显著差异（P＜0.05），不同年际间梨园土壤Sr含量不存在显著差异。果皮与果肉Sr元素含量存在极显著相关（P＜0.01），但二者与土壤Sr元素含量均不存在显著相关。3 个产地梨果肉/果皮Sr含量不存在显著差异。3 个产地87Sr/86Sr同位素比值存在显著差异（P＜0.05）。果皮Sr同位素更适合用于库尔勒香梨产地鉴别研究。本实验通过稳定同位素技术为库尔勒香梨产地鉴别提供参考。     

Structural and thermal behavior of 45S5 Bioglass®-based compositions containing alumina and strontium

The present research exposes the influence of 2 mol% of Al₂O₃ and 2 mol% SrO in 45S5 Bioglass^®-based compositions. Four compositions were produced to elucidate the difference in how both oxides influence structure and thermal behavior separately and their synergy when together. Thermal properties, crystallization tendency, and sintering behavior was evaluated by differential scanning calorimetry, hot stage microscopy, and dilatometry. Changes of medium-range structures were characterized by Qⁿ distribution of Raman spectroscopy and evaluation of ³¹P, ²⁷Al, ²³Na, and ²⁹Si environment obtained by magic angle spinning nuclear magnetic resonance. Despite Qⁿ distribution was predominantly Q² in all samples, the composition criteria used enabled improved processing and stabilibity characteristics. The addition of Al₂O₃ and SrO promoted larger sinterability parameter (S_c) which indicates better sintering behavior, the glass stability against crystallization doubled (K_H) compared to 45S5 and the processing window enlarged from 106 to 171.     

基于镧锶锰氧化物基阴极的中温固体氧化物燃料电池的性能优化研究

为了提高基于镧锶锰氧化物(LaxSr1-xMnO3,LSM)阴极的中温固体氧化物燃料电池(Solid Oxide Fuel Cell,SOFC)的电化学性能,文章利用CuO清扫Ce0.85Sm0.15O2-δ(SDC)晶界的SiO2杂质以提高SDC的离子电导率,制备了复合电解质材料SDC-CuO,并将SDC-CuO和LSM结合成复合阴极材料,随后分别制备了以LSM和LSM/SDC-CuO作为阴极的SOFC,并研究了这两种SOFC的电化学性能。研究结果表明:在开路电压和工作温度为800℃的条件下,LSM/SDC-CuO基阴极的SOFC的极化电阻为0.14Ω·cm2,明显低于LSM基阴极SOFC的极化电阻(0.36Ω·cm2);LSM/SDC-CuO基阴极的SOFC的最大输出功率密度为237 mW/cm2,显著高于LSM基阴极的SOFC的最大输出功率密度(132 mW/cm2)。     

含锶饮用天然矿泉水的形成

本文根据实际调查资料．初步揭示了含锶饮用天然矿泉水的形成条件、机理及分布与岩性的关系。     

BST-BSL体系的烧结行为和介电性能

采用草酸盐共沉淀工艺制备高反应活性Ba0.6Sr0.4TiO3(BST)粉体,添加适量的B2O3-SiO2-Li2O(BSL)为烧结助剂,采用传统陶瓷制备工艺制备BST-BSL复相陶瓷。用扫描电镜(SEM)和X射线衍射(XRD)分别研究BST-BSL的微观形貌和相组成,并测试BST-BSL的介电性能参数。结果表明:添加的少量B2O3-Li2O-SiO2在烧结过程中与BST主晶相发生复杂的化学反应,使BST的烧结温度由1 350℃降低到1 000℃以下;B2O3-Li2O-SiO2的添加大幅改善BST的介电常数温度稳定性,引入的非铁电第二相对BST铁电性的‘稀释作用’使BST-BSL的可调率降低,但由于烧结助剂的添加量少,使BST-BSL在1 kV/mm外加偏场下的可调率仍在5%以上。     

化学共沉淀工艺制备钛酸锶钡纳米粉体

以硝酸钡、硝酸锶、草酸和钛酸丁酯为原料,采用草酸盐共沉淀法制备草酸氧钛锶钡(BSTO,Ba0.6Sr0.4TiO(C2O4)2·4H2O)前躯体粉体,将该前躯体800℃煅烧4h得到钛酸锶钡(BST,Ba0.6Sr0.4TiO3)纳米粉体。用差热分析仪研究BSTO的热分解过程,用X射线衍射仪(XRD)和扫描电镜(SEM)研究钛酸锶钡粉体的相组成和微观形貌。结果表明:BSTO前驱体的热分解过程可以分为失去结晶水、草酸氧钛跟(TiO(C2O4)22-)分解和BST结晶化3个阶段;所制备的钛酸锶钡粉体为高纯立方晶相,粉体呈类球状,平均粒径约为100nm。     

以天青石矿为原料生产高纯硫酸锶工艺研究

针对青海天青石矿的特点以及高纯硫酸锶的市场特性、生产关键技术与配套工艺的关键性问题，提出具有针对性、先进性并可实现产业化的生产高纯硫酸锶的工艺方案。重点提出了以碳还原法加工天青石矿制取高纯硫酸锶的工艺路线。通过单因素实验确定了最佳工艺条件：煅烧温度为1 200 ℃，天青石精矿和煤粉的质量比为5∶1，硫化锶浸取温度为90 ℃，氢氧化锶溶液和稀硫酸的质量比为1∶1.1。在此条件下，高纯硫酸锶的平均收率为95.53%。实验制备的硫酸锶产品为白色，纯度为99.3%，各项指标达到化学纯的要求。     

铜矿石中铋的测定

铜矿石试样经王水分解后,在10%王水介质中,于223.06nm处用原子吸收分光光度计测定铋。此法适用于铜矿石中0.020%～3%的铋的测定。