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159 results on '"Chen, Junnian"'

10. Narrow‐Bandgap Mixed 0D/1D Bismuth Bromide Perovskite Hydrate Enabled by Aromatic Ditertiary Ammonium Spacer.

Author

Chen, Junnian, Xiao, Xingfu, Chen, Yue, Li, Mingkai, Fang, Wenyu, Yu, Zixian, He, Biqi, Zhai, Tianyou, and He, Yunbin

Subjects
*BAND gaps, *BISMUTH, *CONDUCTION bands, *PEROVSKITE, *BROMIDE ions, *BROMIDES, *GAS hydrates
Abstract

Perovskite hydrates have attracted extensive attention in diverse fields with intriguing optoelectronic properties, while their structural distortions usually cause large band gaps, which yield inferior light absorption and diminished optoelectronic device performance. Herein, modulating the structural distortion by steric hindrance effects is reported. Specifically, an N,N,N′,N′‐tetramethyl‐1,4‐phenylenediammonium (TMPD)2+ is adopted to template regular BiBr5 chains by interacting with bismuth bromide via weakening and reorienting H‐bonds, yielding a mixed 0D/1D (TMPD)2Bi2Br10.H2O with a narrow bandgap of 1.89 eV. The 0D/1D (TMPD)2Bi2Br10.H2O can be reversibly transformed into 0D (TMPD)2Bi2Br10 (Eg = 2.55 eV) with good cycling behavior. The (TMPD)2Bi2Br10.H2O turns out to be more stable than (TMPD)2Bi2Br10, and a mechanism involving vacancy‐assisted bromide ion migration is proposed for understanding the formation of BiBr5 chains. Density functional theory (DFT) calculations indicate that the (TMPD)2+ triggered hydration has a crucial impact on the downshift of the conduction band edge, thus decreasing the band gap. Moreover, the (TMPD)2Bi2Br10.H2O single crystal exhibits promising photoconductive behavior under a high moisture atmosphere, showing superiority over the conventional CH3NH3PbI3 perovskites that cannot survive moisture. This finding offers new insights into developing narrow band gap perovskite hydrates toward practical optoelectronic applications. [ABSTRACT FROM AUTHOR]

Published
2023
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11. Broadband red emission from one-dimensional hexamethonium lead bromide perovskitoid.

Author

He, Biqi, Kuang, Kuan, Xu, Bing, Tang, Junjie, Cao, Sheng, Yu, Zixian, Li, Mingkai, He, Yunbin, and Chen, Junnian

Subjects
LEAD, LEAD halides, BROMIDES, PEROVSKITE
Abstract

Broadband emissions from low-dimensional hybrid perovskites have aroused intense interest. However, the achievement of broadband red emission in lead halide perovskites remains challenging. Herein, we report a one-dimensional (1D) hybrid lead bromide perovskitoid, (HM)Pb2Br6 (HM = hexamethonium), featuring a corrugated "3 × 3" [Pb2Br6]2− chain. The unique structure results in intriguingly red emission peaking at 692 nm, with a PLQY of around 6.24%. Our spectroscopic and computational studies reveal that the red emission derives from self-localized Pb23+, Pb3+ and Br2− species confined within the inorganic lead bromide lattice that function as radiative centres. This finding will benefit the design of perovskite systems for efficient red emission. [ABSTRACT FROM AUTHOR]

Published
2023
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21. Diagenetic Facies and Their Controls on the Quality of Tight Sandstone Reservoirs: A Case Study from the Upper Paleozoic Gas Reservoir in the Eastern Ordos Basin, North China.

Author

Qin, Xiaoli, Li, Rongxi, Chen, Lei, Jiao, Kun, Cheng, Jinghua, Khaled, Ahmed, Yao, Limiao, and Chen, Junnian

Subjects
PARAGENESIS, PETROPHYSICS, GAS reservoirs, FACIES, NATURAL gas prospecting, QUALITY control, PALEOZOIC Era
Abstract

Diagenetic facies play a significant role in the evaluation and prediction of reservoirs as they comprehensively reflect the spatial distribution characteristics of deposition, diagenesis, and petrophysical properties. Based on the petrographic observation and considering pores, lithology, and diagenesis types, the diagenetic facies types were identified, and the pore evolution process and its influence on the quality of low permeability tight gas reservoirs were analyzed. The results show that six types of diagenetic facies were identified, including siliceous cementation intergranular pore facies (A), carbonate dissolution pore facies (B), matrix dissolution pore facies (C), clastic dissolution pore facies (D), matrix filling and strong compaction tight facies (E), and carbonate cementation and metasomatism tight facies (F). The evolution process of porosity shows that the restored original porosity is indicated to be between 34.2% and 36.0%. The average porosity loss caused by compaction was 17.1%, while the average porosity loss caused by cementation is 14.1%. The average porosity increased by 2.5% on diagenetic facies B, C, and D due to dissolution. Consequently, diagenetic facies A with weak compaction and diagenetic facies B, C, and D with strong dissolution are effective reservoirs with porosity greater than 6.6% and permeability greater than 0.25 − 0.6 × 10 − 3 μm2. The distribution areas of A, B, C, and D are favorable areas for tight gas exploration and are important indicators for the prediction of tight gas in the Upper Paleozoic Shanxi Formation in the eastern Ordos Basin. This study provides a new petrographic method for reservoir prediction and exploration of natural gas, which has practical value and economic significance. [ABSTRACT FROM AUTHOR]

Published
2023
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32. sj-docx-1-eji-10.1177_20587392211027083 – Supplemental material for Performance of CURB-65, PSI, and APACHE-II for predicting COVID-19 pneumonia severity and mortality

Author

Chen, Junnian, Liu, Bang, Du, Houwei, Lin, Hailong, Chen, Cunrong, Rao, Shanshan, Yu, Ranjie, Wang, Jingjing, Xue, Zhiqiang, Zhang, Yixian, and Xie, Yanghuang

Subjects
110203 Respiratory Diseases, 70706 Veterinary Medicine, FOS: Clinical medicine, FOS: Veterinary sciences, Cell Biology, FOS: Health sciences, Biochemistry, FOS: Biological sciences, Medicine, 110309 Infectious Diseases, 111702 Aged Health Care, 111403 Paediatrics, 111599 Pharmacology and Pharmaceutical Sciences not elsewhere classified, 69999 Biological Sciences not elsewhere classified
Abstract

Supplemental material, sj-docx-1-eji-10.1177_20587392211027083 for Performance of CURB-65, PSI, and APACHE-II for predicting COVID-19 pneumonia severity and mortality by Junnian Chen, Bang Liu, Houwei Du, Hailong Lin, Cunrong Chen, Shanshan Rao, Ranjie Yu, Jingjing Wang, Zhiqiang Xue, Yixian Zhang and Yanghuang Xie in European Journal of Inflammation

Published
2021
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38. Antisolvent‐assisted Crystallization of Centimeter‐sized Lead‐free Bismuth Bromide Hybrid Perovskite Single Crystals with X‐ray Sensitive Merits.

Author

Xu, Yaxin, Hu, Jiarui, Du, Xinyuan, Xiao, Xinglin, Li, Mingkai, Tang, Jiang, Chen, Junnian, and He, Yunbin

Subjects
SINGLE crystals, CHARGE carrier lifetime, BISMUTH, PEROVSKITE, X-ray detection, X-rays
Abstract

Hybrid bismuth halides perovskites have emerged as promising candidates for X‐ray detection, due to the strong absorptivity of high‐energy X‐ray photons, high resistivity, large carrier diffusion length and low toxicity. However, the mostly investigated hybrid bismuth iodides single crystals are usually opaque and require a harsh synthesis process. Herein, novel one‐dimensional (1D) pentamethylenediamine bismuth bromide (PDA)BiBr5 single crystals were synthesized via an antisolvent‐assisted crystallization method at room temperature. Bulk (PDA)BiBr5 single crystals have sizes of 10×1.3×1.5 mm3 and high transparency. They are shown to have low density of defects of 2.0×1010 cm−3 and obvious photoconductivity. Moreover, they exhibit large bulk resistivity of 2.13×1011 Ω cm and good X‐ray attenuation coefficient. Consequently, the vertical structured (PDA)BiBr5 single crystal X‐ray photoconductor produces a sensitivity of 3.8 μC Gyair−1 cm−2. This study provides a facile strategy for synthesizing bulk hybrid bismuth bromides single crystals with potential X‐ray detection application. [ABSTRACT FROM AUTHOR]

Published
2021
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39. Morusin alleviates mycoplasma pneumonia via the inhibition of Wnt/β-catenin and NF-κB signaling

Author

Chen, Cunrong, primary, Wang, Jingjing, additional, Chen, Jianfei, additional, Zhou, Lili, additional, Wang, Hui, additional, Chen, Junnian, additional, Xu, Zhihui, additional, Zhu, Shuaijun, additional, Liu, Wei, additional, Yu, Ranjie, additional, Lu, Junli, additional, Luo, Haoteng, additional, Chen, Min, additional, and Chen, Weiwen, additional

Published
2019
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45. New anthracene-based organic dyes: the flexible position of the anthracene moiety bearing isolation groups in the conjugated bridge and the adjustable cell performance

Author

Li, Huiyang, primary, Fang, Manman, additional, Xu, Ting, additional, Hou, Yingqin, additional, Tang, Runli, additional, Chen, Junnian, additional, Liu, Linfeng, additional, Han, Hongwei, additional, Peng, Tianyou, additional, Li, Qianqian, additional, and Li, Zhen, additional

Published
2016
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46. Organic Sensitizers Featuring 9,10-Diaryl-Substituted Anthracene Unit

Author

Li, Huiyang, primary, Yang, Yizhou, additional, Hou, Yingqin, additional, Tang, Runli, additional, Duan, Tainan, additional, Chen, Junnian, additional, Wang, Heng, additional, Han, Hongwei, additional, Peng, Tianyou, additional, Chen, Xingguo, additional, Li, Qianqian, additional, and Li, Zhen, additional

Published
2014
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