Organic triplet–triplet annihilation upconversion (TTA-UC) materials have considerable promise in areas as broad as biology, solar energy harvesting, and photocatalysis. However, the development of highly efficient near-infrared (NIR) light activatable TTA-UC systems remains extremely challenging. In this work, we report on a method of systematically tailoring an annihilator to attain such outstanding systems. By chemical modifications of a commonly used perylene annihilator, we constructed a family of perylene derivatives that have simultaneously tailored triplet excited state energy (T1) and singlet excited state energy (S1), two key annihilator factors to determine TTA-UC performance. Via this method, we were able to tune the TTA-UC system from an endothermic type to an exothermic one, thus significantly elevating the upconversion performance of NIR light activatable TTA upconversion systems. In conjunction with the photosensitizer PdTNP (10 μM), the upconversion efficiency using the optimal annihilator (100 μM) identified in this study was measured to be 14.1% under the low-power density of NIR light (100 mW/cm2, 720 nm). Furthermore, using such a low concentration of perylene derivative, we demonstrated that the optimal TTA-UC pair developed in our study can act as a highly effective light wavelength up-shifter to enable NIR light to drive a photoredox catalysis that otherwise requires visible light. We found that such an NIR driven method is highly effective and can even surpass directly visible light driven photoredox catalysis. This method is important for photoredox catalysis as NIR light can penetrate much deeper in colored photoredox catalysis reaction solutions, especially when done in a large-scale manner. Furthermore, this TTA-UC mediated photoredox catalysis reaction is found to be outdoor sunlight operable. Thus, our study provides a solution to enhance NIR activatable organic upconversion and set the stage for a wide array of applications that have previously been limited by the suboptimal efficiency of the existing TTA upconversion materials.
This study tested the cross-cultural validity of a modified version of Lent's (2004) normative well-being model. Data of 317 Taiwanese and 259 Singaporean college students were collected using the Mandarin and English versions of the survey and were analyzed using structural equation modeling techniques. Satisfactory fit showed that the modified model offered a reasonable representation of the relations among the constructs and accounted for substantial amounts of the variances in academic well-being and life satisfaction for both samples. Results of the bootstrapping procedure revealed that indirect effects of personality traits and self-construal variables on well-being outcomes were mediated mostly by pathways that involved academic self-efficacy, academic goal progress, and/or academic supports. Academic well-being also filtered the effects of other predictors on life satisfaction. Multigroup structural equation modeling analyses indicated the presence of measurement equivalence across these 2 groups. However, several structural paths differed significantly between the Taiwanese and the Singaporean samples. Overall, this study provides evidence for the applicability of the modified well-being model to college students in Taiwan and Singapore and suggests that students in these 2 Asian countries might pursue and maintain their well-being through different psychological mechanisms. Practical implications for interventions and outreach programs as well as directions for future research are discussed.
Negative photoconductivity (NPC) and positive photoconductivity (PPC) are observed in the same individual InAs nanowires grown by metal-organic chemical vapor deposition. NPC displays under weak light illumination due to photoexcitation scattering centers charged with hot carrier in the native oxide layer. PPC is observed under high light intensity. Through removing the native oxide layer and passivating the nanowire with HfO, we eliminate the NPC effect and realize intrinsic photoelectric response in InAs nanowire.
ABSTRACT. The relationships between fungal aerosols and air pollutants r r r r r meteorological factors were investigated in the Taipei urban area. In summer, it ( ) was observed that geometric mean GM concentrations of airborne fungal aerosols were 2,835 CFU m I 3 and 2,651 CFU m I 3 at Kuting and Hsichih stations, respectively. In winter, GM levels of airborne fungi were 1,107 CFU m I 3 and 2,248 CFU m I 3 at Kuting and Hsichih stations, respectively. Moreover, fungal aerosol concentrations were observed to highly depend on weather conditions, and the highest concentration of total colony counts appeared when the temperature was 25-308 C, the RH was 60-70%, and the wind speed was -1 m s I 1 and from the S-SE wind direction. In addition, total fungal concentrations were negatively correlated with ozone concentrations, and concentration of Cladosporium spp. was positively correlated with hydrocarbons . PM were positively correlated with 10 Penicillium and the yeasts in Hsichih station. Our results demonstrated that airborne fungal aerosols are de nitely correlated with air pollutants and meteorological factors. The complex dynamic interactions were indicated to occur among bioaerosols, air pollutants, and meteorological factors.
One-step synthesis of fluorescent molecules (SNBDP) containing one disulfide bond and two o-nitrobenzyl groups was demonstrated via multi-component Passerini reaction.
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