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Your search keyword '"Zhao, Jianfen"' showing total 7 results
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7 results on '"Zhao, Jianfen"'

2. Multi-Resonant Indolo[3,2,1- jk ]carbazole-Based Host for Blue Phosphorescent Organic Light-Emitting Diodes.

Author

Li, Xiang, Yuan, Peng, Song, Jinyu, Chang, Yu, Jiao, Xueting, Zhao, Jianfen, Zhang, Cong, Li, Wenjuan, and Hang, Xiao-Chun

Subjects
LIGHT emitting diodes, ELECTRON transport, CHARGE carriers, TRANSPORTATION rates, CARBAZOLE, EXCITON theory
Abstract

In organic light-emitting diodes, positive and negative charge carriers mostly migrate at different rates. This could result in excitons formed in the EML often migrating to the vicinity of the hole transport layer and the electron transport layer. To address this, it is important to design high-quality multi-resonance hosts that can balance the migration rate of carriers. Here, we report two newly developed multi-resonance hosts, m-ICzPBI and o-ICzPBI. The hosts contain an indolo[3,2,1-jk]carbazole (ICz) motif, which functionalized as either a donor or an acceptor unit. The hosts exhibit extremely high molecular rigidity and thermal stability. Devices A and B were constructed using FIrpic as a phosphorescent emitter with m-ICzPBI or o-ICzPBI as a host. Device A achieved high maximum values of EQE, PE and CE of 13.4%, 24.8 lm W−1 and 31.6 cd A−1, respectively, and low efficiency roll-off at 5000 cd m−2 of 8.6%, 10.6 lm W−1 and 20.3 cd A−1, respectively. [ABSTRACT FROM AUTHOR]

Published
2023
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4. Role of scalp hypothermia in patients undergoing minimally invasive evacuation of hypertensive cerebral hemorrhage

Author

Zhang, Yueling, Song, Ling, and Zhao, Jianfen

Subjects
Micro-traumatic evacuation of cerebral hemorrhage, Hypertensive cerebral hemorrhage, Original Article, Mild hypothermia
Abstract

Objective: Hypertensive intracerebral hemorrhage (HICH) is one of the common multiple diseases in neurology. Patients with severe HICH have high risk of disability and poor prognosis. Methods: In order to explore the clinical effect of mild hypothermia combined with micro-traumatic evacuation of cerebral hemorrhage in the treatment of severe HICH, 136 patients with severe HICH were selected and divided into control group and study group using random number table method, 68 each group. The control group was treated with micro-traumatic evacuation of cerebral hemorrhage on the basis of conventional symptomatic treatment, while the study group was treated with mild hypothermia combined with micro-traumatic evacuation of cerebral hemorrhage on the basis of conventional symptomatic treatment. After treatment, the two groups were followed up for eight weeks. Results: The overall effective rate, residual hematoma volume, rebleeding rate, National Institute of Health stroke scale (NIHSS) score, Barthel index score and incidence of adverse reactions after treatment were observed and compared. The overall effective rate of the study group was 89.7%, which was significantly higher than that of the control group (67.6%). The mortality rate of the study group was 3.0%, which was significantly lower than that of the control group (14.7%, P0.05). After treatment, they were improved, and the improvement of the study group was more significant (P

Published
2019

7. Energy Level, Crystal Morphology and Fluorescence Emission Tuning in Cocrystals via Molecular-Level Engineering.

Author

Zhang J, Chen J, Yang B, Ma S, Yin L, Liu Z, Xiang W, Liu H, Zhao J, and Sheng P

Abstract

Organic donor-acceptor complexes as new organic semiconductor class have attracted wide attention, due to their potential applications in functional optoelectronics. Herein, we present two new charge transfer cocrystals of di-cyanodiazafluorene -perylene (DCPE) and di-cyanodiazaflfluorene-pyrene (DCPY) through a rational cocrystal-engineering strategy. Although they are both 1 : 1 mixed stacking cocrystals with similar chemical structures, the DCPE cocrystal possesses a non-centrosymmetric space group and narrower band gap compared to DCPY cocrystal, because of the non-covalent bonding variation. The electrostatic potential accumulated in the lateral facets leads to highly twisted DCPE nanobelts, and the small band gap causes near infrared fluorescence. Meanwhile, the DCPY crystals with centrosymmetric space groups and weaker intermolecular interactions exhibited an untwisted morphology and red emission. This study will be helpful for the design and understanding of functional cocrystal materials that can be used in flexible micro/nano-mechanics, mechanical energy, and optical devices., (© 2022 Wiley-VCH GmbH.)

Published
2023
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