To improve the seismic performance of prefabricated reinforced conventional concrete (PRC) beam‐column joints, fiber‐reinforced concrete (FRC) was used instead of concrete in the core zone of the joint in this article. The optimum volume contents of polyvinyl alcohol (PVA) fibers and steel fibers were first determined to be 0.3% and 1%, respectively, through the material properties tests. Then, four PRC beam‐column joint specimens using grouted sleeve connections and one cast‐in‐place reinforced concrete beam‐column joint specimen were designed considering the factors of PVA fibers, steel fibers, with or without stirrups. The test phenomena and failure mode of the five specimens under low‐cycle cyclic loads were obtained. Finally, the effects of PVA fibers, steel fibers, with or without stirrups on the seismic performance of specimens were analyzed and discussed. The test phenomena indicated that the failure mode of specimens was anchorage damage of steel bars. The prefabricated FRC specimens showed relatively little damage in the core zone of the joint. FRC had a significant improvement on the seismic performance of prefabricated beam‐column joints. The use of FRC in the core zone of the joint can reduce or even eliminate the use of stirrups.

Perovskite light-emitting diodes (PeLEDs) have attracted much attentions due to the superior optoelectronic properties such as pure spectrum, high photoluminescence quantum yield, tunable emission, and ease of fabrication. Though lots of progresses have been made on PeLEDs and optically pumped lasers, microcavity perovskite lasing device under electrical pumping remains extremely challenging. Microcavity perovskite LEDs can be considered as a step toward laser diode due to the common structure of resonant cavity. In this study, a new type of metal-dielectric microcavity PeLED is designed and fabricated by using 2.5 pairs of TiO 2 /SiO 2 distributed bragg reflector (DBR) and Al as cavity coplanar mirrors. A microcavity device with forward spectral full-width at half-maximum of 11.8 and 9.5 nm, under electrical and optical excitations, respectively, the directional forward emission within 30°is enhanced by 3 times compared to the control device without cavity is realized. To the best of the knowledge, this study demonstrates the narrowest spectrum for three-demisional PeLEDs so far, it helps to expand the color space in display applications and may also serve as a reference device for solution processed perovskite exciton-polariton electroluminescent devices and electrically driven vertical cavity surface emitting lasers due to the similar device structure and processing.

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