Theoretical study of determining orientation and alignment of symmetric top molecule using laser-induced fluorescence

General expressions used for extracting the orientation and alignment parameters of a symmetric top molecule from laser-induced fluorescence (LIF) intensity are derived by employing the density matrix approach. The molecular orientation and alignment are described by molecular state multipoles. Excitation and detection are circularly and linearly polarized lights, respectively. In general cases, the LIF intensity is a complex function of the initial molecular state multipoles, the dynamic factors and the excitation-detection geometrical factors. It contains a population, ten orientation and fourteen alignment multipoles. The problem of how to extract the initial molecular state multipoles from the resolved LIF intensity is discussed.     

Secondary-beam production: Protons versus heavy ions

The construction of two new-generation complementary RIB facilities in Europe, one based on the in-flight fragmentation or fission (IFF) method (FAIR) and the other on the isotope separation on-line (ISOL) method (EURISOL) is expected in the next 10-15 years. The reaction mechanisms, responsible for the production of the secondary nuclei, along with the technical constrains, have to be considered for the designs of the facilities. In this work, we study which reaction mechanisms can be exploited at best for the production of the secondary beams in the two facilities.     

All‐Inorganic Lead‐Free 0D Perovskites by a Doping Strategy to Achieve a PLQY Boost from <2 % to 90 %

Zero‐dimensional (0D) lead‐free perovskites have unique structures and optoelectronic properties. Undoped and Sb‐doped all inorganic, lead‐free, 0D perovskite single crystals A₂InCl₅(H₂O) (A=Rb, Cs) are presented that exhibit greatly enhanced yellow emission. To study the effect of coordination H₂O, Sb‐doped A₃InCl₆ (A=Rb, Cs) are also synthesized and further studied. The photoluminescence (PL) color changes from yellow to green emission. Interestingly, the photoluminescence quantum yield (PLQY) realizes a great boost from <2 % to 85–95 % through doping Sb³⁺. We further explore the effect of Sb³⁺ dopants and the origin of bright emission by ultrafast transient absorption techniques. Furthermore, Sb‐doped 0D rubidium indium chloride perovskites show excellent stability. These findings not only provide a way to design a set of new high‐performance 0D lead‐free perovskites, but also reveal the relationship between structure and PL properties.     

Alkylphenyl Substituted Naphthodithiophene: A New Building Unit with Conjugated Side Chains for Semiconducting Materials

In this article, a versatile 2‐D conjugated polymer, PNDTP‐DPP, containing alkylphenyl substituted naphthodithiophene is synthesized and characterized. PNDTP‐DPP exhibits good solubility and crystallinity with a π−π stacking distance of ≈3.7 Å. Investigation of polymer solar cells (PSCs) and organic field‐effect transistors (OFET) demonstrates a promising power conversion efficiency (PCE) of 4.11% and a high hole mobility of up to 0.86 cm² V^–1 s^–1, so this is one of the few examples of versatile polymers that show both good field‐effect mobility and PCE.

     

纳米铜粒子制备及二次稳定的研究

选用硫酸铜为原料,十六烷基三甲基溴化铵(CTAB)为稳定剂,以硼氢化钠为还原剂,采用液相还原法制备纳米铜颗粒。CTAB既是一种表面活性剂又是一种稳定剂。添加十二烷基苯磺酸钠(SDBS)对制备的纳米铜溶胶进行二次稳定。考察铜盐及稳定剂对所形成的铜纳米粒子的稳定性的影响。通过紫外-可见分光光度计、X射线衍射仪和透射电子显微镜等表征手段对纳米铜进行表征。结果显示,紫外吸收光谱在570nm处有纳米铜特征吸收峰,SDBS二次稳定后的纳米铜颗粒无论在形貌上还是分散性上都有所改善。XRD图谱通过Scherrer计算得出铜纳米粒子平均粒径为13nm,与透射图像分析吻合。     

稀土苯甲酸盐的合成及热分解反应机制

由水热法合成了稀土苯甲酸盐配合物Ｌｎ（Ｃ６Ｈ５ＣＯＯ）３（Ｌｎ＝Ｌａ,Ｎｄ,Ｓｍ,Ｅｕ、Ｇｄ、Ｄｙ、Ｅｒ）。用元素分析、ＩＲ、Ｘ射线粉末衍射表征了该系列配合物。它们都为层状结构,属单斜晶系。用ＴＧ、ＤＴＡ、ＩＲ、色谱－质谱联用仪研究了它们的热分解机制。在氮气氛下,热分解分两步进行：先分解生成二碳酸一氧盐和有机化合物;而后二碳酸一盐进一步分解生成稀土氧化物和二氧化碳。第二步中生成的有机化合物成分比较