In recent years, perovskite solar cells have attained unprecedented advancements in power conversion efficiency, yet their commercialization remains a formidable challenge. Addressing this challenge ...relies on developing an affordable and scalable method for manufacturing top‐notch perovskite films. This study presents an innovative strategy, employing both gas quenching technology and ultrasonic‐assisted processing (UAP), to fabricate high‐caliber perovskite thin films. The UAP process enhances the grain size of the perovskite film, reduces grain boundary defects, improves carrier extraction and transport, and suppresses carrier nonradiative recombination. Furthermore, it effectively reduces residual stress and mitigates lattice distortion in the perovskite crystals. Ultimately, efficient and stable inverted perovskite solar cells using FA0.87Cs0.13PbI2.7Br0.3 and FA0.85MA0.1Cs0.05PbI3 perovskite are successfully prepared. The target device achieved a power conversion efficiency of 22.32% and 24.51%, respectively. Moreover, the target devices exhibited enhanced photostability. This work provides a cost‐effective and scalable method for producing high‐quality perovskite films, paving the way for the commercialization of perovskite solar cells.
This study presents an innovative strategy, employing both gas quenching technology and ultrasonic‐assisted processing (UAP), to fabricate high‐caliber perovskite thin films. The UAP promotes the growth of nuclei by enhancing mass and heat transfer through microscopic mixing that improves the film quality. Ultimately, the inverted perovskite solar cells with a champion efficiency of 24.5% are successfully demonstrated.
We report the search results of light dark matter through its interactions with shell electrons and nuclei, using the commissioning data from the PandaX-4T liquid xenon detector. Low energy events ...are selected to have an ionization-only signal between 60 to 200 photoelectrons, corresponding to a mean nuclear recoil energy from 0.77 to 2.54 keV and electronic recoil energy from 0.07 to 0.23 keV. With an effective exposure of 0.55 tonne·year, we set the most stringent limits within a mass range from 40 MeV/c^{2} to 10 GeV/c^{2} for pointlike dark matter-electron interaction, 100 MeV/c^{2} to 10 GeV/c^{2} for dark matter-electron interaction via a light mediator, and 3.2 to 4 GeV/c^{2} for dark matter-nucleon spin-independent interaction. For DM interaction with electrons, our limits are closing in on the parameter space predicted by the freeze-in and freeze-out mechanisms in the early Universe.
Ultrasonic shot peening (USP) is a surface strengthening method used to improve the surface and service properties. In this paper, assembled ultrasonic horns with vibration bolts made of 304 ...stainless steel (SS), TC4 alloy, and SKD11 steel were developed to investigate the shot dynamics and target property as a function of horn material, the hardness and yield stress of which vary. The impact detection experiments and FEM results demonstrated that the SKD11 horn produced the largest maximum impact velocity and effective impact frequency, followed by TC4 and 304SS horns. This finding was related to the varying degrees of plastic deformation of the horns and the kinetic energy consumption. As the plastic deformation of the horn became more severe, the impact velocity and frequency on the target decreased. Moreover, material testing results indicated that the use of SKD11 horn resulted in the highest surface hardness, highest residual compressive stress, and maximum amount of martensite in 304SS targets within the shortest time, which could be attributed to the highest impact velocity and frequency. Finally, the relationships between the horn material and shot dynamics, and between the horn material and target properties were clarified, providing valuable insights into the optimization of USP parameters in industrial applications.
•Assembled ultrasonic horns with vibration bolts made of 304SS, TC4 alloy and SKD11 steel are developed.•SKD11 horn excites balls at the largest impact velocity and effective impact frequency, followed by TC4 and 304SS horns.•The shot dynamics is related to the plastic deformation degree of vibration horns.•By using SKD horn, target can obtain the best properties within the shortest time.
This retrospective study aimed to evaluate the safety and efficacy of continuous renal replacement therapy (CRRT) during percutaneous coronary intervention (PCI) in patients with severe acute ...myocardial infarction (AMI). The study analyzed data from 945 AMI patients hospitalized between January 2016 and December 2017, out of which 21 patients underwent perioperative CRRT for PCI. We assessed the baseline characteristics of severe AMI patients before and after CRRT and examined the effect of CRRT on cardiac, renal, and liver function, as well as other indicators. The heart rate of patients undergoing CRRT was significantly lower at 24 h and 48 h after CRRT than before CRRT (p=0.038). There was a moderate but not significant decrease in the mean systolic blood pressure or diastolic blood pressure (p>0.05). Importantly, we found that significantly more patients showed Killip class I-II and significantly improved cardiac function after CRRT (23.8% vs. 57.1%, p=0.001). The levels of urea nitrogen, creatinine, aspartate aminotransferase, glutamic pyruvic transaminase, and total bilirubin were significantly lowered after CRRT treatment (p<0.05). Perioperative management of CRRT was safe and effective for severe AMI patients.
We present the constraints on the axial-vector and pseudo-scalar mediated WIMP-nucleus interactions from the PandaX-4T experiment, using the data set corresponding to a total exposure of 0.63 ...tonne⋅year. No significant signal excess is observed, and the most stringent constraints to date on the mediator mass are set for the axial-vector and pseudo-scalar simplified models. The maximum excluded mass of an axial-vector mediator is 825 GeV/c2 and that of a pseudo-scalar mediator is 106 GeV/c2. In addition, the upper limits on the spin-dependent WIMP-nucleon scattering cross-section for conventional neutron-only and proton-only interactions are derived.
It is commonly conjectured that dark matter is a charge neutral fundamental particle. However, it may still have minute photon-mediated interactions through millicharge
or higher-order multipole ...interactions
, resulting from new physics at a high energy scale. Here we report a direct search for effective electromagnetic interactions between dark matter and xenon nuclei that produce a recoil of the latter from the PandaX-4T xenon-based detector
. Using this technique, the first constraint on the charge radius of dark matter is derived with the lowest excluded value of 1.9 × 10
fm
for a dark matter mass of 40 giga electron volts per speed of light in a vaccum squared (GeV/c
), more stringent than that for neutrinos by four orders of magnitude. Constraints on the magnitudes of millicharge, magnetic dipole moment, electric dipole moment and anapole moment are also improved substantially from previous searches
, with corresponding tightest upper limits of 2.6 × 10
e, 4.8 × 10
Bohr magnetons, 1.2 × 10
ecm and 1.6 × 10
cm
, respectively, for a dark matter mass of 20-40 GeV/c
.
