Adsorption of thorium(IV) on magnetic multi-walled carbon nanotubes

The influences of pH, contact time, solid-liquid ratio, temperature and C60(C(COOH)2)n on Th(IV) adsorption onto the magnetic multi-walled carbon nanotubes(MMWCNTs) were studied by batch technique. The dynamic process showed that the adsorption of Th(IV) onto MMWCNTs could reach equilibrium in 40 h and matched the pseudo-second-order kinetics model. The adsorption of Th(IV) onto MMWCNTs was significantly dependent on pH values, the adsorption ratio increased markedly at pH 3.0–5.0, and then maintained a steady state as pH values increased. At low pH, different C60(C(COOH)2)n content could enhance the adsorption content of Th(IV) onto MMWCNTs, but restrained it at higher pH. Through simulating the adsorption isotherms by Langmuir, Freundlich and Dubini-Radushkevich models, it could be seen respectively that the adsorption pattern of Th(IV) onto MMWCNTs was mainly surface complexation, and that the adsorption process was endothermic and irreversible.     

Instability Origin and Improvement Scheme of Facial Alq3 for Blue OLED Application

Degradation phenomenon and poor stability of tris(8-hydroxyquinoline) aluminum(III)(Alq₃)-based organic light-emitting diodes(OLEDs) have attracted much attention. In this paper, we discussed the origin of instability of the facial Alq₃-based blue luminescent OLEDs with the help of first-principles calculation. The results show that environmental humidity seriously affects the luminescence stability of Alq₃-based OLEDs. H₂O molecules in environment can be firmly bound to the oxygen atoms of the facial Alq₃, which then act as starting points for further degradation of Alq₃. Moreover, the interactions between facial Alq₃ and different cathode metal layers were investigated to explain the experiment phenomenon. A design guideline for diminishing the strong attraction from oxygen atoms can be proposed to protect Alq₃ and improve the stability of materials applied in OLEDs.     

局域共振声子晶体的离散化及其线缺陷研究

提出了一种局域共振声子晶体基本模型,将其散射体离散化,研究了二者的能带结构及隔声曲线.采用有限元法结合超原胞技术,将离散模型引入基本模型组成的超原胞中,研究了多种形式的线缺陷对能带结构及隔声曲线的影响.结果表明,离散模型比基本模型具有更宽的带隙,同时隔声效果更好;通过引入线缺陷,可以在能带结构中产生缺陷带,声波被局域在缺陷处只能沿缺陷传播,缺陷带的数量及位置受到线缺陷形式的影响;同时,线缺陷形式影响隔声效果,横向和纵向复合线缺陷隔声效果最好.研究结果可以为声子晶体的实际工程应用提供一定的理论参考.     

搅拌-超声氧化锆纳米管脱色降解甲基橙的研究

采用阳极氧化法在有机溶液中制备氧化锆纳米管,以搅拌-超声方法研究其对甲基橙的脱色降解性能.实验采用不同pH值的甲基橙溶液,发现氧化锆纳米管对较强酸性的甲基橙溶液有较理想的脱色降解效果.对比氧化锆粉体、纳米管未退火、退火后(600℃)三种材料,退火后的氧化锆纳米管的脱色降解性能整体最佳.XRD测试显示退火后氧化锆纳米管阵列呈现单斜和四方相的混合体.通过FTIR测试脱色降解后的氧化锆纳米管阵列,显示材料中已经不存在甲基橙分子结构,对比研究发现醌式结构和偶氮式两种结构下脱色降解机理相同.     

二氧化硅@羟基磷灰石颗粒的制备及其药物装载与体外释放行为研究

以改性的St(o)ber方法制备二氧化硅核心颗粒,并用改性的Pechini方法在其表面沉积羟基磷灰石壳层,制备得到具有核壳结构的二氧化硅@羟基磷灰石颗粒.通过扫描电子显微镜、X射线衍射分析和红外光谱分析手段表征颗粒的物相和结构,确定颗粒的形成机制为羟基磷灰石壳层在聚乙二醇-柠檬酸作用下均匀地沉积在非晶态二氧化硅表面.含亚甲基蓝的二氧化硅@羟基磷灰石药物颗粒在磷缓冲液(pH =7.2 ～7.4)和lysosome-like缓冲液(pH=4.7)中的释放行为表明药物释放对颗粒结构和溶液的pH值非常敏感.     

基于智能算法的二维声子晶体最优结构设计

利用智能算法和平面波展开法计算了二维二组元和二维三组元声子晶体的最优材料参数和尺寸参数.平面波展开法结合智能算法来进行结构设计,通过改变结构的尺寸和材料类型,在给定材料和尺寸约束下,使二维二组元和二维三组元声子晶体的相对带隙宽度达到最大,为声子晶体最优结构设计做出了探索.     

数字化实验在化学核心素养“宏观辨识与微观探析”维度的教学应用——以弱电解质的教学为例

依托人教版《化学反应原理（选修4）》教材,利用数字化实验测定无限稀释冰醋酸过程中的电导率和pH的变化,通过宏观现象观察和图像辨识,从微观上深入解析弱电解质的电离特征,突破越稀越电离的认识边界。在激发学生学习兴趣和学习动力的同时,从“宏观辨识与微观探析”维度帮助学生形成整合的弱电解质结构性知识,探索化学平衡的思维规律。     

In-situ Reduction Synthesis of Bi/BiOI Heterostructure Films with High Photoelectrochemical Activity

The Bi/BiOI heterostructure films grew perpendicular to the FTO substrates were synthesized in-situ tlirough an electrochemical deposition and hydrogen reduction metliod. The metallic Bi nanoparticles were decorated onto the surface of BiOI nanosheets via an in-situ reduction, induced 6.3 times improvement of photocurrent density, compared to the pristine BiOI at 1.23 V vs. reversible hydrogen electrode(RHE).The enhancement of photoelectrochemical perfomiance was attributed not only to the efficient separation of charge resulted from surface plasmon resonance efleet, but also to the fast charge transfer at the interface due to the in-situ reduction of the films. This work provided a simple and facile strategy to in-situ construct heterostnicture films, and showed an effective metliod to improve the photoelectrochemical activity of Bi-based semiconductors.     

Solvothermal Syntheses and Characterization of Three One-dimension Cadmium Selenidoarsenates [Ni(1,2-dap)3][As2CdSe4],[Zn(1,2-dap)3][As2CdSe4] and [Ni(en)3][As2CdSe4]

Three new cadmium selenidoarsenates,[Ni(1,2-dap)3][As2CdSe4](1)(1,2-dap=l,2-diaminopropane),[Zn( 1,2-dap)3][As2CdSe4](2) and [Ni(en)3][As2CdSe4](3)(en=ethylenediamine), were synthesized under solvothermal conditions. And they are isostnictural and monoclinic crystalls. As seen from their structures, they exhibited one-dimensional(1D) chains composed of [As2CdSe4]^2- anions and [TM(amine)3]^2+(TM=Ni,Zn;amine=1,2-dap, en) cations. Their absorption edges are 2.32, 1.84 and 2.38 eV and they show the properties of the semiconductor. These compounds were also characterized by means of single-crystal X-ray ditlraction(XRD), powder X-ray diflraction (PXRD), solid-state optical absorption spectrometry, and so on.