Energy‐transfer dynamics of blue‐phosphorescent iridium and rhodium complexes doped in fluorescent molecules

Abstract— The temperature‐dependent photoluminescence features of polycarbonate thin films doped with blue‐phosphorescent molecules, either bis[(4,6‐difluorophenyl)‐pyridinato‐N,C^2′] (picolinate) iridium (Flrpic) or bis(2‐phenylpyridinato‐N,C^2′) (acetylacetonate) rhodium [(ppy)²Rh(acac)], which have an equivalent triplet energy of 2.64 eV, have been studied. The photoluminescence intensity of the Flrpic‐doped polycarbonate thin film did not show any dependence on temperature. On the other hand, as for the (ppy)²Rh(acac)‐doped polycarbonate thin film, decreasing photoluminescence intensity with increasing temperature (especially above 100K) was clearly visible. These results reflect that the internal heavy‐atom effect of (ppy)²Rh(acac) is weaker than that of Flrpic. Furthermore, the steady‐state and time‐resolved photoluminescence spectra of tris(8‐hydroxyquinoline) aluminum (Alq₃) thin films heavily doped with Flrpic or (ppy)²Rh(acac) (50 wt.%) at 8K was studied. It was found that the enhanced phosphorescence from Alq₃ is mainly due not to the external heavy‐atom effect by doping with the phosphorescent molecule but to the exothermic triplet energy transfer from the phosphorescent molecule to Alq₃.     

Highly efficient single‐unit white OLED device with emission from both singlet and triplet excitons

We succeeded in developing a single‐unit hybrid organic light‐emitting diode (OLED) device with efficient light emission from both a phosphorescent layer and a fluorescent layer. The single‐unit hybrid OLED achieved a power efficiency higher than that of a two‐unit hybrid tandem OLED with phosphorescent and fluorescent layers.     

Charge carriers and charge‐transfer reactions in OLED devices studied by electron paramagnetic resonance*

Abstract— Electron paramagnetic resonance (EPR) was used as a quantitative method to measure charge carriers that are present in OLED devices under various bias conditions. Charge‐transfer reactions that occur at the cathode interface through the interaction of charge‐injection layers and charge‐transport layers were investigated.     

高能物理事例级数据管理与传输系统的研究

高能物理实验不断的进步与发展产生了PB乃至EB级的数据,这些数据的采集、存储、传输与共享、分析与管理都面临着极大的问题与挑战。为了应对这些挑战,设计和实现了面向事例的数据管理系统,有效解决事例数据处理效率低以及分站点资源利用率低的问题。设计了一个基于Nosql数据库的事例索引系统,通过事例数据特征抽取,选取物理学家最感兴趣的属性作为索引,存储在数据库中,并采用倒排索引技术,提高事例数据检索的效率。针对事例数据进行缓存优化,减少数据转化和存储开销。提出数据跨域传输方案,充分利用网络带宽,降低分站点处理数据的延迟。系统进行了相关验证,实验结果表明,事例级的索引技术能够显著提高事例数据的检索效率,数据传输系统的网络带宽也可以利用到百分之九十以上。     

Adaptive transfer learning in deep neural networks: Wind power prediction using knowledge transfer from region to region and between different task domains

Transfer learning (TL) in deep neural networks is gaining importance because, in most of the applications, the labeling of data is costly and time consuming. Additionally, TL also provides an effective weight initialization strategy for deep neural networks. This paper introduces the idea of adaptive TL in deep neural networks (ATL‐DNN) for wind power prediction. Specifically, we show in case of wind power prediction that adaptive TL of the deep neural networks system can be adaptively modified as regards training on a different wind farm is concerned. The proposed ATL‐DNN technique is tested for short‐term wind power prediction, where continuously arriving information has to be exploited. Adaptive TL not only helps in providing good weight initialization, but also in utilizing the incoming data for effective learning. Additionally, the proposed ATL‐DNN technique is shown to transfer knowledge between different task domains (wind power to wind speed prediction) and from one region to another region. The simulation results show that the proposed ATL‐DNN technique achieves average values of 0.0637, 0.0986, and 0.0984 for the mean absolute error, root mean squared error, and standard deviation error, respectively.