Real-time spectroscopic tracking of efficient intersystem crossing triggered by the heavy-atom effect in di-heteroatomic organic phosphorescent molecules.

The development of efficient and long-lived halogen-free organic phosphorescent molecules remains a challenge. For the single-heteroatomic 9,10-dihydroacridine (AcH), the evolution of singlet and triplet excited state absorption signals reveals an intersystem crossing (ISC) lifetime of 8.2 ns and a triplet state lifetime of 0.

Effective promotion of steric hindrance effect on singlet-triplet transition of para-linked carbazole-biphenyl by transient absorption spectroscopy.

The para-linked carbazole-biphenyl (CBP) is commonly utilized in phosphorescent organic light-emitting diodes. This study investigates the steric hindrance and heavy-atom effects in CBP derivatives through transient absorption spectroscopy. In contrast to CBP, CBP derivatives shows new triplet-triplet absorption signals and isosbestic points, accompanied by the decay of excited state absorption signal, which indicates the occurrence of intersystem crossing (ISC).

Enhanced Electrochemical Performance and Cycling Stability of the (NH)[VVO(OH)]·11HO Cathode in Aqueous Zinc Ion Batteries.

Although vanadium-based compounds possess several advantageous characteristics, such as multivalency, open structure, and high theoretical specific capacity, which render them highly promising candidates for cathode materials in aqueous zinc ion batteries (AZIBs), their large-scale application still necessitates addressing the challenges posed by slow kinetics resulting from low conductivity and capacity degradation caused by material dissolution. Therefore, we have successfully synthesized high-purity mixed multivalent (NH)[VVO(OH)]·11HO (NVO) crystalline materials via a liquid-phase precipitation modulation method and employed it as an innovative AZIB cathode material for the first time. It exhibits a remarkable reversible specific capacity of 240 and 102.

Dynamic response of axle box bearing for high-speed train considering wheelset flexibility and polygonal wear.

In this study, a flexible wheelset was added to a rigid-flexible coupled vehicle dynamics model, in which the axle box bearings are accurately modeled. The measured wheel's polygon wear profile and Wuhan-Guangzhou track spectrum are used in the model to define the wheel tread and track irregularity, respectively. We conducted a field test on the Wuhan-Guangzhou railway line to validate the model.

Transient Absorption Spectroscopy of a Carbazole-Based Room-Temperature Phosphorescent Molecule: Real-Time Monitoring of Singlet-Triplet Transitions.

Real-time monitoring of singlet-triplet transitions is an effective tool for studying room-temperature phosphorescent molecules. For femtosecond transient absorption (TA) spectroscopy of a 2,6-di(9-carbazol-9-yl) pyridine molecule in dimethyl sulfoxide (DMSO), the stimulated emission signal (380 nm) and the excited-state absorption signal (650 nm) reach their maximum intensity within 397 fs. Subsequently, the two signals decay with time and the triplet-triplet absorption (TTA) signal (400 nm) is enhanced synchronously, accompanied by an isosbestic point at 491 nm.

Theoretical investigation on the fluorescence properties and ESIPT mechanism of the Al ion sensor 1-((2-hydroxynaphthalen-1-yl)methylene)urea(OCN).

A new action mechanism for the fluorescent detection on the Al ion of the sensitive 1-((2-hydroxynaphthalen-1-yl)methylene)urea(OCN) is theoretically studied. The extensive theoretical calculations on the OCN and the isomer structure OCN-T are performed. The emission and absorption spectra consistent with the experiment value.