添加Al2O3对Ni0.5Zn0.5Fe2O4纳米纤维结构和磁性能的影响

采用静电纺丝技术制备了添加0～20wt%Al2O3的Ni0.5Zn0.5Fe2O4纳米纤维。通过XRD、FESEM、TEM和VSM对样品的物相结构、形貌和磁性能进行了表征。结果表明,所合成的复合纳米纤维的直径都分布在40～150 nm之间,添加到纤维中的Al2O3主要以非晶态形式分布于铁氧体晶粒边界;随着Al2O3添加量的增加,可观察到γ-Fe2O3相逐渐析出,Ni-Zn铁氧体的晶格常数单调减小,说明有一些Al2O3进入到尖晶石晶格中取代了B位的Fe3+离子,Ni-Zn铁氧体的平均晶粒尺寸先增大后减小,在Al2O3添加量为8wt%时达到最大值39.2 nm;比饱和磁化强度和矫顽力随Al2O3添加量的增加呈现出相同的变化规律,先减小后增大,当Al2O3添加量超过5wt%时又开始变小。     

CS/La0.7Ca0.3Fe0.25Co0.75O3复合纳米颗粒的制备及光催化性能研究

采用甘氨酸-硝酸盐燃烧法成功的制备了La0.7 Ca0.3 Fe0.25 Co0.75 O3钙钛矿型复合氧化物,将钙钛矿La0.7Ca0.3Fe0.25Co0.75O3与壳聚糖(CS)共混交联制备出一种新型的光催化剂,通过XRD、SEM、FT-IR对催化剂的结构进行了表征.以酸性橙为对象,高压汞灯紫外光为光源,研究了一...     

Zn掺杂的LaCoO3钙钛矿用于乙醇水蒸气重整制氢反应

利用一步柠檬酸络合法合成了钙钛矿LaCo1-xZnxO3(x=0,0.05,0.1,0.2,0.3,0.5),并将其用于乙醇水蒸气重整反应.利用X射线衍射、程序升温还原和X射线光电子能谱对催化剂进行了表征.结果表明,Zn的加入不利于形成LaCo1-xZnxO3钙钛矿结构,当x≥0.1时产生了一些分离相.新鲜LaCo0....     

单管高灵敏度等温扩增技术快速检测甲型H1N1流感病毒

建立了单管逆转录环介导等温扩增法(RT-LAMP)快速检测甲型H1N1流感病毒的方法.针对甲型H1N1流感病毒的M基因和HA基因的保守区,设计了两组特异性引物,分别用于筛选甲型流感病毒及鉴定甲型H1N1流感病毒.对反应体系中的关键因素进行优化,反应结果可直接通过浊度或者SYBR Green Ⅰ荧光进行判定.本方法最低可...     

Detection of cortisol at a gold nanoparticle|Protein G-DTBP-scaffold modified electrochemical immunosensor

An ultrasensitive electrochemical immmunosensor was demonstrated to be capable of detecting the hormone cortisol down to concentrations as low as 16 pg mL(-1). In addition, the immunosensor displayed a sensitivity of 1.6 μA pg(-1) mL(-1) and a linear range up to ～2500 pg mL(-1) of cortisol. This immunosensor was constructed based on a Au nanoparticle|dimethyl 3,3'-dithiobispropionimidate·2HCl (DTBP)-Protein G scaffold-modified Au electrode. In this work, the Au nanoparticles were used to increase the electrochemically active surface area by 28% (with a standard deviation of 3%) to enhance the quantity of the Protein G scaffold on the electrode. Thiolation of Protein G by DTBP aided in avoiding the confirmation change of Protein G, while this Protein G-DTBP component offered an orientation-controlled immobilisation of the capture antibody on the Au electrode. In this immunosensor, a monoclonal anti-cortisol capture antibody was optimally aligned by the scaffold before a competitive immunoassay between sample cortisol and a horseradish peroxidase-labelled cortisol conjugate was conducted. For quantitative analysis, square wave voltammetry was used to monitor the reduction current of benzoquinone produced from a horseradish peroxidase catalysed reaction. The improved analytical performance of our immunosensor was attributed to the synergetic effect of Au nanoparticles and the Protein G-DTBP scaffold.     

Cycloaddition reactions of N-heterocyclic stable silylenes with ethylene and formaldehyde

The cycloaddition reactions of N-heterocyclic silylenes 1-4 with ethylene (C₂H₄) and formaldehyde (CH₂O) molecules were performed at the MP2/6-31G** level of theory, respectively. Full optimizations and frequency analyses were done for the stationary points on the potential energy surface. The intrinsic reaction coordinate (IRC) was also calculated for all the transition states at the same level of theory. The possible cycloaddition mechanisms were investigated and results from various reactions were compared in detail. The theoretical results indicated that the cycloaddition reactions of N-heterocyclic silylenes with C₂H₄ and CH₂O proceeded through a concerted mechanism to form a three-membered ring containing C1, C2 (O), and Si atoms in the products, which was similar to those of simple silylene H₂Si. Silylenes 1-4 exhibit some electrophilicity toward C₂H₄ whereas nucleophilicity toward CH₂O leading to the reaction process. Based on the reaction energy barrier and the exothermic energy, the reaction activities of saturated silylene (2) were stronger than those of unsaturated silylenes (1, 3, and 4).     

F16CuPc作为阳极缓冲层对有机太阳能电池性能的显著改善

采用F₁₆CuPc作为有机太阳能电池的阳极缓冲层可使器件的性能得到显著提高。F₁₆CuPc的引入,一方面可以实现CuPc分子的定向生长,从而改善CuPc薄膜的结晶度,提高其空穴迁移率;另一方面在F₁₆CuPc/CuPc界面处可形成偶极层,改善空穴的输出效率。以上两个作用有效提高了器件的载流子收集效率,降低了器件的串联电阻和光生载流子复合几率,从而提高了器件的短路电流和填充因子。同时,F₁₆CuPc的引入使器件的内建电场增大,提高了器件的开路电压。     

N-苄基-N′-（氨基对苯磺酸钠）硫脲的合成及与钯的显色反应

合成了显色剂N-苄基-N′-（氨基对苯磺酸钠）硫脲（BSATu）,并研究了其与Pd（Ⅱ）的显色反应。在pH 4.0的醋酸-醋酸钠缓冲溶液中,该试剂与钯离子形成摩尔比为3∶1的棕色配合物,其最大吸收波长为282nm,表观摩尔吸光系数达到4.12×104L.mol-1.cm-1,Pd（Ⅱ）的浓度在0—2.4μg/mL范围内符合朗伯-比耳定律。该法用于测定催化剂中钯的含量,结果满意。     

电感耦合等离子体-质谱法同时测定雷公藤中常量及微量元素

采用微波消解法对雷公藤进行消解制样,用电感耦合等离子体-质谱法(ICP-MS)同时测定了其常量及微量元素,并研究了常量及微量元素的含量特征.方法的相对标准偏差(RSD)＜9％,回收率在90.0％-103.0％之间.结果表明,中药雷公藤中含有比较丰富的K、Ca、Fe、Mg、Mn、Zn等元素,对人体有害的微量元素Pb、Cd...