新型有机电致磷光白光器件的研究

制备了结构为ITO/NPB/TCTA/FIrpic∶TCTA/Ir(MDQ)2(acac)∶TmPyPB/FIrpic∶TmPyPB/TmPyPB/LiF/Al的有机电致磷光发光器件。通过在双蓝光发光层之间插入较薄的红光层Ir(MDQ)2(acac)∶TmPyPB调节载流子、激子在各发光层中的分布,并结合TCTA和TmPyPB对发光层内载流子和激子的有效阻挡作用,混合实现白光发射。研究了红光层在不同厚度、不同掺杂浓度下对器件发光性能的影响。结果表明,红光发光层厚度为2nm、质量浓度为5%时,结合蓝光发光层和红光发光层,实现了色坐标为(0.333,0.333)、最大发光效率为11.50cd/A的白光发射。     

122~125Sn中子谱因子的实验研究

多个Sn同位素位于慢速中子俘获（s-）过程路径上,其中子谱因子可用于计算ASn（n,γ） A+1Sn直接辐射俘获的天体物理反应率,并可研究Sn同位素对s-过程核合成的贡献。本工作在中国原子能科学研究院HI-13串列加速器Q3D磁谱仪上,对实验室系下8°~66°范围内的122,124Sn（d,p）和（p,d）单中子转移反应角分布进行了测量。利用DWBA理论计算了转移反应角分布,并提取了122-125Sn的基态以及123,125Sn第一激发态的中子谱因子。其中,122Sn和124Sn的基态中子谱因子是首次从实验上获得。由于本工作成功鉴别开了123,125Sn的基态和第一激发态的效应,因此给出的谱因子比前人的结果更可信。Several Tin isotopes are on the path of slow neutron capture (s-) process, and the direct components of (n, γ) reactions can be derived from their neutron spectroscopic factors. In the present work, the angular distributions of 122,124Sn(p, d) and (d, p) reactions are obtained using the high-precision Q3D magnetic spectrograph in Beijing HI-13 tandem accelerator in China Institute of Atomic Energy. The distorted-wave Born approximation (DWBA) calculations are performed to extract the neutron spectroscopic factors of the ground state of 122-125Sn and the first excited state of 123,125Sn. The neutron spectroscopic factors of the ground state of 122Sn and 124Sn are firstly obtained in this work. As the events of the ground state and first excited state of 123,125Sn can be distinguished clearly by our experiment, the neutron spectroscopic factories of 123,125Sn are more reliable.     

锦屏深地核天体物理实验(JUNA)地面实验进展

锦屏深地核天体物理(JUNA)实验项目将利用中国锦屏深地实验室(CJPL)的良好条件，在天体物理伽莫夫能量窗口开展核天体关键反应$^{25}{\rm{Mg}}({\rm{p}},{\rm{\gamma}})^{26}{\rm{Al}}$、$^{19}{\rm{F}}({\rm{p}},\alpha)^{16}{\rm{O}}$、$^{13}{\rm{C}}(\alpha, {\rm{n}})^{16}{\rm{O}}$和$^{12}{\rm{C}}(\alpha,{\rm{\gamma}})^{16}{\rm{O}}$的直接测量，为理解恒星演化和元素起源提供新的数据。目前，已经在地面上对加速器装置、束流稳定性、靶、探测器以及电子学进行了系统的测试。地面实验内容包括高纯锗探测器效率刻度，$^{25}{\rm{Mg}}({\rm{p}}, {\rm{\gamma}})^{26}{\rm{Al}}$在304 keV的共振强度测量，$^{19}{\rm{F}}({\rm{p}}, \alpha)^{16}{\rm{O}}$的截面测量，聚乙烯作为慢化体的中子探测器的设计、加工和效率刻度，靶的设计和稳定性检测等。JUNA项目整体进展顺利，地面实验已取得一系列关键进展和初步成果。在不远的将来，JUNA项目将有序开展地下实验，完成设定目标，也将促进更广泛的国际合作，助力于天体演化中的若干重大科学问题的解决。     

基于MoO_3/Au/MoO_3透明电极的有机太阳能电池

以透明导电薄膜Mo O3/Au/Mo O3代替铟锡氧化物(ITO)作为有机太阳能电池(OSCs)的阳极,研究了一系列结构为Mo O3/Au/Mo O3的透明电极和Mo O3(y nm)/Au(x nm)/Mo O3(y nm)/Cu Pc(25 nm)/C60(40nm)/BCP(8 nm)/Al(100 nm)的有机太阳能电池。研究表明,Mo O3/Au/Mo O3电极的光电特性可通过改变各层薄膜厚度加以调控,在Mo O3薄膜厚度为40 nm、Au薄膜厚度为10 nm时性能最优,且以该薄膜为电极的有机太阳能电池器件的性能接近于电极为ITO的有机太阳能电池器件。     

利用18O(6Li,d)22Ne反应研究22Ne Eα=470 keV共振态的性质

慢速中子俘获过程（s过程）是合成比铁重元素的重要途径之一。22Ne（α,n）25Mg反应是大质量AGB星中s过程主要的中子源,其中的22Ne主要通过14N（α,γ）18F（β+）18O（α,γ）22Ne反应链合成。该反应链中关键反应18O（α,γ）22Ne在天体物理感兴趣能区的截面非常低,其天体反应率主要来自于22Ne α分离阈附近低能共振态的贡献,但目前相关能级的共振参数严重缺失。在HI-13串列加速器的Q3D磁谱仪上,通过测量18O（6Li,d）22Ne反应的角分布,利用DWBA分析确定了22Ne分离阈附近共振能级E_α=470 keV的自旋宇称为0+,为后续计算18O（α,γ）22Ne的天体反应率打下了基础。About a half of the abundances of elements heavier than iron comes from the so-called slowneutron capture process (s-process) in Asymptotic Giant Branch (AGB) stars, with the 22Ne(α, n)25Mg reaction as one of the main neutron sources. In the beginning phase of AGB thermal pulse, 22Ne is produced by the 14N(α, γ)18F(β+)18O(α, γ)22Ne reaction sequence, in which the 18O(α, γ)22Ne reaction plays a key role. While the reaction rate of the 18O(α, γ)22Ne is mainly affected by several resonant states lying closely to the α threshold in 22Ne, up to now, the relevant 22Ne parameters are fragmentary in the energy region corresponding to the typical temperatures of s-process. The direct measurement of the 18O(α, γ)22Ne reaction rate is extremely difficult due to the very low cross section. In this work, we investigated the 22Ne resonant states via the 18O(6Li, d)22Ne reaction at the Beijing HI-13 tandem accelerator of China Institute of Atomic Energy. Based on the DWBA analysis, preliminary results showed that the spin-parity of 22Ne E_α=470 keV resonant states was assigned as 0+, which would make contributions to subsequent calculation for the reaction rate of the 18O(α, γ)22Ne.     

10Be中子谱因子的实验研究

核谱因子描述了单粒子轨道中核子的占有状态,在核结构和核天体物理中有重要的应用。目前国际上10Be中子谱因子的研究结果存在3倍左右的差异。本实验利用中国原子能科学研究院HI-13串列加速器的高灵敏度Q3D磁谱仪,对13C（9Be,10Be）12C反应角分布进行了精确测量。通过实验数据和扭曲波玻恩近似（DWBA）计算结果进行比较,导出了10Be的中子谱因子。该结果与转动不变壳模型理论及曾敏尔等的评价结果基本一致。利用该结果可以得到9Be（n,γ）10Be的天体物理反应率,评价该反应在相关天体环境中对CNO循环种子核12C的影响,为核结构和核天体物理提供可靠数据。Spectroscopic factor describes the overlap between the initial and final states and gives some information on the occupancy of a given single-particle orbiting around nuclear. It plays an important role in a variety of topics on nuclear structure and nuclear astrophysics. Nowadays, several experiments have been performed to study the neutron spectroscopic factor of 10Be, but the results have a big difference with each other. In order to clarify this discrepancy, new measurement is highly needed. In this work, the angular distribution of 13C(9Be,10Be)12C reaction was measured at the Q3D magnetic spectrometer of the HI-13 tandem accelerator, China Institute of Atomic Energy, Beijing. And then, the neutron spectroscopic factor of 10Be was derived by normalizing the calculational differential cross-sections with the distorted-wave Born approximation to the experimental data. The present value is in good agreement with that obtained by Tsang et al. and also in good agreement with that derived from translationary invariant shell model calculation. One can use this result to calculate the 9Be(n, γ)10Be reaction rates and calculate its influence to the production of 12C.