In the past period of time, perovskite solar cells have gained tremendous developments in improving photovoltaic performance, but they still face severe challenges. Defects in perovskite layers, especially at grain bo...In the past period of time, perovskite solar cells have gained tremendous developments in improving photovoltaic performance, but they still face severe challenges. Defects in perovskite layers, especially at grain boundaries, severely limit the stabilization and efficiency of solar cells. In this work, we adopt 3-carboxyphenylboronic acid(CPBA) for modifying defects in perovskite thin films. Through the interaction among the carboxyl group, boronic acid and lead ions in the perovskite film, the crystallization effect of the perovskite molecular is greatly optimized. Moreover, the film defects are spontaneously passivated and the band gap is reduced, increasing the open circuit voltage and fill factor. Therefore,power conversion efficiency has been increased from 17.25% to 20.20%. This discovery provides a potential strategy for passivating the trap states in perovskite and enhancing the properties of devices.展开更多
目的:对比三维多回波恢复梯度回波(3D MERGE)、三维可变反转角快速自旋回波(3D SPACE STIR)序列在腰椎间盘突出症(LDH)检查中的应用效果。方法:选择2020年1月~2022年11月收治的135例LDH患者,回顾性分析患者临床和磁共振成像(MRI)资料,...目的:对比三维多回波恢复梯度回波(3D MERGE)、三维可变反转角快速自旋回波(3D SPACE STIR)序列在腰椎间盘突出症(LDH)检查中的应用效果。方法:选择2020年1月~2022年11月收治的135例LDH患者,回顾性分析患者临床和磁共振成像(MRI)资料,所有患者均接受常规MRI扫描及3D MERGE、3D SPACE STIR序列扫描,对比3D MERGE、3D SPACE STIR序列测量神经根直径的一致性,评价两种序列的图像质量参数[信噪比(SNR)、对比噪声比(CNR)]、图像清晰度评分。结果:3D MERGE和3D SPACE STIR序列测量的L3~S1神经根直径比较差异无统计学意义(P>0.05),且两组序列测量的L3、L4、L5和S1直径均显示出较高相关性(r=0.957,0.986,0.975,0.972,P<0.05);3D MERGE序列的SNR及CNR均高于3D SPACE STIR序列,神经根显示分级、图像清晰度评分优于3D SPACE STIR序列,差异有统计学意义(P<0.05)。结论:3D MERGE、3D SPACE STIR序列在LDH神经根直径测量中具有极高一致性,3D MERGE序列较3D SPACE STIR序列能够更清晰显示神经跟的解剖形态,图像质量更好。展开更多
基金Project supported by the Regional Joint Fund of the National Science Foundation of China (Grant No. U21A20492)the Sichuan Science and Technology Program (Grant Nos. 2022YFH0081, 2022YFG0012, and 2022YFG0013)+1 种基金sponsored by the Sichuan Province Key Laboratory of Display Science and TechnologyQiantang Science & Technology Innovation Center。
文摘In the past period of time, perovskite solar cells have gained tremendous developments in improving photovoltaic performance, but they still face severe challenges. Defects in perovskite layers, especially at grain boundaries, severely limit the stabilization and efficiency of solar cells. In this work, we adopt 3-carboxyphenylboronic acid(CPBA) for modifying defects in perovskite thin films. Through the interaction among the carboxyl group, boronic acid and lead ions in the perovskite film, the crystallization effect of the perovskite molecular is greatly optimized. Moreover, the film defects are spontaneously passivated and the band gap is reduced, increasing the open circuit voltage and fill factor. Therefore,power conversion efficiency has been increased from 17.25% to 20.20%. This discovery provides a potential strategy for passivating the trap states in perovskite and enhancing the properties of devices.
文摘目的:对比三维多回波恢复梯度回波(3D MERGE)、三维可变反转角快速自旋回波(3D SPACE STIR)序列在腰椎间盘突出症(LDH)检查中的应用效果。方法:选择2020年1月~2022年11月收治的135例LDH患者,回顾性分析患者临床和磁共振成像(MRI)资料,所有患者均接受常规MRI扫描及3D MERGE、3D SPACE STIR序列扫描,对比3D MERGE、3D SPACE STIR序列测量神经根直径的一致性,评价两种序列的图像质量参数[信噪比(SNR)、对比噪声比(CNR)]、图像清晰度评分。结果:3D MERGE和3D SPACE STIR序列测量的L3~S1神经根直径比较差异无统计学意义(P>0.05),且两组序列测量的L3、L4、L5和S1直径均显示出较高相关性(r=0.957,0.986,0.975,0.972,P<0.05);3D MERGE序列的SNR及CNR均高于3D SPACE STIR序列,神经根显示分级、图像清晰度评分优于3D SPACE STIR序列,差异有统计学意义(P<0.05)。结论:3D MERGE、3D SPACE STIR序列在LDH神经根直径测量中具有极高一致性,3D MERGE序列较3D SPACE STIR序列能够更清晰显示神经跟的解剖形态,图像质量更好。