呋喃西林水溶液在光和热作用下的稳定性

The influence of both light and heat on the stability of nitrofurazone aqueous solution was studied. Results show that in either heating experiments or the exposure to light at high temperatures, the degradation rate obeyed zero-order kinetics. The total rate constant ktotal caused by both light and heat can be divided into two parts: ktotal =kdark klight, where kdark and klight are the degradation rate constants caused by heat and light, respectively. The klight can be expressed as klight=Alight*exp(-Ea,light/RT)*E, where E is the illuminance of light, and Alight and Ea,light both are experimental constants. The values of these kinetic parameters were determined based on the experiments in the dark and upon exposure to three different light sources. Results show that the values of Alight and Ea, light varied with the light source. To save time, labor, and drugs, exponential heating experiments were employed and compared with the isothermal experiments. Results indicated that kinetic parameters obtained by exponential heating experiments are comparable to those obtained by isothermal experiments either in the dark or upon exposure to light.     

压强对钙钛矿薄膜形貌和结晶性影响的研究

采用新型简便的方法控制钙钛矿层薄膜的结晶过程,对优化制备工艺、获得高性能器件至关重要。本文采用调节真空度的方法有效控制钙钛矿层结晶,系统地研究了压强的作用及其对晶体生长、薄膜形成及器件性能的影响。采用扫描电子显微镜(SEM)、紫外-可见吸收光谱、X射线衍射光谱(XRD)谱图等手段对钙钛矿层的形貌及结晶程度进行了分析表征。在此基础上,制备出器件结构为Glass/ITO/PEDOT:PSS/CH3NH3PbI3/PCBM/Al的钙钛矿太阳能电池,考察了不同压强下的器件性能。结果表明:随压强降低,钙钛矿层结晶程度明显提高,孔洞减少,表面覆盖率提高。同时,器件的短路电流、填充因子以及光电转化效率均随压强降低而提高,器件效率由原来的10.38%提高到12.36%,提高了19%。     

预防放射病药物的研究——一些双巯胺及其酰肼化合物的合成

本文报道带有多巯基的β-巯基乙胺(MEA)和巯基丙胺(MPA)衍生物7,8,9及多巯基酰肼10的合成。由β,β'-(双苄硫基)异丁酸(16)或酯(14)分别经叠氮钠或水合肼作用,可获得化合物17和15,17,15及20经钠-液氨脱苄基,醋酸汞沉淀及硫化氢处理,即得高纯度双巯胺化合物7,10及8。由α,γ-双苄硫基丁胺(12)经同法处理可制得2,4-双巯基-1-氨基对甲苯磺酸盐(9)。这些化合物对小白鼠急性电离辐射损伤均有一定防护作用,其中化合物9具有中等防护效果。     

浊度滴定法

报道了一种实用的浊度传感器及浊度滴定仪，以及一种利用此仪器检测溶液的浑浊程度（溶液中散射光相对强度）来判断沉淀反应滴定终点的方法。将一束光线通入溶液，在溶液中与其垂直的方向上，利用内置浊度传感器检测散射光相对强度；随着滴定剂的加入，溶液将渐变得浑浊，散射光相对强度逐渐增强。如果沉淀反应完全且溶解度足够小，散射光相对强度将在化学计量点处达最大值，由此可判断滴定终点。以AgNO3溶液滴定NaCl溶液为例俊证了浊度滴定法，结果表明：浊度滴定法样化学指示剂法适用于更低的浓度；在适当的条件下浊度滴定法的精密度和准确度均可＜0.2%。