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Aiming at the abnormal vibration phenomenon of low-pressure cylinder during the debugging period of a new 660 MW ultra-supercritical steam turbine unit， through vibration test and analysis， it is concluded that the bearing bush of low-pressure cylinder has low dynamic stiffness and its resonance frequency is close to the working speed， if the shaft vibration climbs due to factors such as dynamic and static rubbing， the tile vibration will be caused to climb significantly. At the same time， it is found that the gap between the low-pressure outer cylinder and the cosmetic plate is too small， which will induce the generation of low-frequency structural resonance. During the operation of the unit， measures are taken to adjust the steam supply temperature of the low-pressure shaft seal and control the load of the unit. During the maintenance， measures such as adjusting the clearance of the cosmetic plate of low-pressure cylinder， the installation size of the bearing， and the fine dynamic balance are adopted to reduce the abnormal vibration of the low-pressure cylinder， which improves the stability of the low-pressure cylinder and ensures the safe and reliable operation of the units.

Defects in perovskite films are one of the main factors that affect the efficiency and stability of halide perovskite solar cells (PSCs). Uncoordinated ions (such as Pb2+, I−) act as trap states, causing the undesirable non-radiative recombination of photogenerated carriers. The formation of Lewis acid–base adducts in perovskite directly involves the crystallization process, which can effectively passivate defects. In this work, 4-(trifluoromethyl)-1H-imidazole (THI) was introduced into the perovskite precursor solution as a passivation agent. THI is a typical amphoteric compound that exhibits a strong Lewis base property due to its lone pair electrons. It coordinates with Lewis acid Pb2+, leading to the reduction in defect density and increase in crystallinity of perovskite films. Finally, the power conversion efficiency (PCE) of PSC increased from 16.49% to 18.97% due to the simultaneous enhancement of open-circuit voltage (VOC), short circuit current density (JSC) and fill factor (FF). After 30 days of storage, the PCE of the 0.16 THI PSC was maintained at 61.9% of its initial value, which was 44.3% for the control device. The working mechanism of THI was investigated. This work provides an attractive alternative method to passivate the defects in perovskite. [ABSTRACT FROM AUTHOR]

Efficient single-layer organic light-emitting diodes (OLEDs) were reported based on a green fluorescent dye 10-(2-benzothiazolyl)-2,3,6,7-tetrahydro-1,1,7,7-tetramethyl-1H,5H,11H-(1) benzopyropyrano (6,7-8-I,j)quinolizin-11-one (C545T). Herein, poly(3,4-ethylenedioxy thiophene) poly(styrene sulfonate) were, respectively, applied as the injection layer for comparison. The hole transport properties of the emission layer with different hole injection materials are well investigated via current-voltage measurement. It was clearly found that the hole injection layers (HILs) play an important role in the adjustment of the electron/hole injection to attain transport balance of charge carriers in the single emission layer of OLEDs with electron-transporting host. The layer of tris-(8-hydroxyquinoline) aluminum played a dual role of host and electron-transporting materials within the emission layer. Therefore, appropriate selection of hole injection layer is a key factor to achieve high efficiency OLEDs with single emission layer. [ABSTRACT FROM AUTHOR]