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Chlorine-Substituent Regulation in Dopant-Free Small-Molecule Hole-Transport Materials Improves the Effi ciency and Stability of Inverted Perovskite Solar Cells
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作者 Xinyi liu Xiaoye Zhang +7 位作者 zhanfeng li Jinbo Chen Yanting Tian Baoyou liu Changfeng Si Gang Yue Hua Dong Zhaoxin Wu 《Transactions of Tianjin University》 EI CAS 2024年第4期314-323,共10页
Although doped hole-transport materials(HTMs)off er an effi ciency benefi t for perovskite solar cells(PSCs),they inevi-tably diminish the stability.Here,we describe the use of various chlorinated small molecules,spec... Although doped hole-transport materials(HTMs)off er an effi ciency benefi t for perovskite solar cells(PSCs),they inevi-tably diminish the stability.Here,we describe the use of various chlorinated small molecules,specifi cally fl uorenone-triphenylamine(FO-TPA)-x-Cl[x=para,meta,and ortho(p,m,and o)],with diff erent chlorine-substituent positions,as dopant-free HTMs for PSCs.These chlorinated molecules feature a symmetrical donor-acceptor-donor structure and ideal intramolecular charge transfer properties,allowing for self-doping and the establishment of built-in potentials for improving charge extraction.Highly effi cient hole-transfer interfaces are constructed between perovskites and these HTMs by strategi-cally modifying the chlorine substitution.Thus,the chlorinated HTM-derived inverted PSCs exhibited superior effi ciencies and air stabilities.Importantly,the dopant-free HTM FO-TPA-o-Cl not only attains a power conversion effi ciency of 20.82% but also demonstrates exceptional stability,retaining 93.8%of its initial effi ciency even after a 30-day aging test conducted under ambient air conditions in PSCs without encapsulation.These fi ndings underscore the critical role of chlorine-substituent regulation in HTMs in ensuring the formation and maintenance of effi cient and stable PSCs. 展开更多
关键词 Hole-transport materials Inverted perovskite solar cells Chlorinated small molecules Donor–acceptor–donor structure
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Experimental study of piperlongumine inducing apoptosis of human breast adenoma MDA-MB-231 cells
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作者 Zhifeng Yao Jianxin Yao +2 位作者 Xia He zhanfeng li Yongbiao liu 《The Chinese-German Journal of Clinical Oncology》 CAS 2013年第7期319-325,共7页
Objective: The aim of the study was to investigate the apoptosis induced by piperlongumine on human breast adenoma MDA-MB-231 cells and the mechanism involved. Methods: Human breast adenoma MDA-MB-231 cells line was... Objective: The aim of the study was to investigate the apoptosis induced by piperlongumine on human breast adenoma MDA-MB-231 cells and the mechanism involved. Methods: Human breast adenoma MDA-MB-231 cells line was cultured in vitro. The inhibitory effect of piperlongumine on the proliferation of human breast adenoma MDA-MB-231 cells was measured by CCK-8 assay. Distribution of cell cycle was analyzed by flow cytometry. The apoptosis rates of MDA-MB- 231 cells were measured using Annexin V/PI staining. The flow cytometry with the probe of DCFH-DA was used to detect the intracellular reactive oxygen species levels. Western blot was used to explore the protein expression of Bcl-2 and Bax. Results: The CCK-8 assay showed that piperlongumine had an inhibiting effect on the proliferation of MDA-MB-231 cells in a concentrationand time-dependent manner. MDA-MB-231 cells were markedly arrested at G0/G1 phase after treatment of piperlongumine. Piperlongumine induced apoptosis of MDA-MB-231 cells obviously. The level of intracellular reactive oxygen species was increased in a dose-dependent manner. The antioxidant N-acetyI-L-cystein inhibited the apoptosis of cells and the level of intracellular reactive oxygen species was also decreased. By Western blot analysis, we found the expression of Bax was up-regulated whereas that of Bcl-2 was down-regulated in a concentration-dependent manner. Conclusion: PiperIongumine possesses a significant function for inhibiting proliferation, arresting cells at G0/G1 phase and inducing apoptosis of MDA-MB-231 cells, which seems to be associated with the increased generation of intracellular reactive oxygen species as well as the down-regulation of Bcl-2 and up-regulation of Bax. 展开更多
关键词 piperlongumine (piplartine PL) human breast adenoma cells cell cycle APOPTOSIS reactive oxygen species BAX Bcl-2
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基坑长距离近接既有线MJS加固效果研究
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作者 李展峰 宋飞 +2 位作者 毕延哲 郭金鑫 伍凯 《工程设计与施工》 2023年第11期24-29,共6页
福州既有地铁1号线与某新建车站基坑主体长距离并行,车站基坑开挖施工可能引起既有线变形过大,影响其安全运营,故采用门式MJS(Metro Jet System)工法桩进行加固处理。为分析MJS工法桩的加固效果,采用三维有限元数值模拟分析对比了加固... 福州既有地铁1号线与某新建车站基坑主体长距离并行,车站基坑开挖施工可能引起既有线变形过大,影响其安全运营,故采用门式MJS(Metro Jet System)工法桩进行加固处理。为分析MJS工法桩的加固效果,采用三维有限元数值模拟分析对比了加固方案和未加固方案的咬合桩水平位移、基底隆起和既有线变形。结果表明,MJS工法桩一方面可以减少咬合桩水平位移和基底隆起,另一方面能有效控制既有线的水平位移,加固效果良好。 展开更多
关键词 地铁车站 既有线 并行 MJS工法 加固设计
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基于鲁棒最优控制的在线机器学习方法
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作者 宁瀚文 李占风 《中国科学:数学》 CSCD 北大核心 2018年第9期1181-1202,共22页
基于再生核Hilbert空间(reproducing kernel Hilbert space,RKHS)的统计学习模型被广泛应用于函数逼近、图像处理、模式识别和回归分析等领域,并且也在非线性随机动力学系统的辨识问题中有着很好的表现.本文提出一个基于鲁棒最优控制的R... 基于再生核Hilbert空间(reproducing kernel Hilbert space,RKHS)的统计学习模型被广泛应用于函数逼近、图像处理、模式识别和回归分析等领域,并且也在非线性随机动力学系统的辨识问题中有着很好的表现.本文提出一个基于鲁棒最优控制的RKHS模型学习方法,来实现对非线性随机动力学系统的高效在线建模.利用本文得到的关于再生核空间的一些理论结果,本文将随机动力学系统的在线学习问题转化为一组具有有界随机扰动的离散时变线性系统的输出反馈镇定问题,并利用模型预测控制技术来设计相应的控制算法和学习算法.与现有的RKHS模型学习方法相比,在不引入任何数据窗口原理、剪枝技术、学习步长的调整机制以及对噪声统计性质的假设的情形下,新方法可以在保证模型参数快速且鲁棒收敛的同时,实现对动力学系统的自适应高精度建模.此外,本文首次从最优控制的视角出发,研究动力学系统的在线核学习问题.在本文提出的研究框架下,现有各种控制技术可以被利用起来开发新的鲁棒学习方法,这也为核学习理论的研究和算法的开发提供一些新的思路.本文亦给出了数值算例和对比结果,用来说明新方法的有效性. 展开更多
关键词 统计学习 在线学习 再生核空间 随机动力学系统 鲁棒最优控制 模型预测控制
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Thermally activated flux flow,vortex-glass phase transition and the mixed-state Hall effect in 112-type iron pnictide superconductors
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作者 XiangZhuo Xing zhanfeng li +10 位作者 XiaoLei Yi JiaJia Feng ChunQiang Xu Nan Zhou Yan Meng YuFeng Zhang YongQiang Pan lingYao Qin Wei Zhou HaiJun Zhao ZhiXiang Shi 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2018年第12期45-52,共8页
The transport properties in the mixed state of high-quality Ca_(0.8)La_(0.2)Fe_(0.98)Co_(0.02)As_2single crystal,a newly discovered 112-type iron pnictide superconductor,are comprehensively studied by magneto-resistiv... The transport properties in the mixed state of high-quality Ca_(0.8)La_(0.2)Fe_(0.98)Co_(0.02)As_2single crystal,a newly discovered 112-type iron pnictide superconductor,are comprehensively studied by magneto-resistivity measurement.The field-dependent activation energy,U_0,is derived in the framework of thermally activated flux flow(TAFF)theory,yielding a power law dependence U_0~H~αwith a crossover at a magnetic field around 2 T in both H⊥ab and H//ab,which is ascribed to the different pinning mechanisms.Moreover,we have clearly observed the vortex phase transition from vortex-glass to vortex-liquid according to the vortex-glass model,and vortex phase diagrams are constructed for both H⊥ab and H//ab.Finally,the results of mixed-state Hall effect show that no sign reversal of transverse resistivityρ_(xy)(H)is detected,indicating that the Hall component arising from the vortex flow is in theories or experiments previously reported on some high-T_ccuprates. 展开更多
关键词 thermally activated flux flow vortex-glass transition mixed-state Hall effect 112-type iron pnictide superconductors
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