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White light-emitting diodes (WLEDs) composed of blue LED chip, yellow phosphor, and red quantum dots (QDs) are considered as a potential alternative for the next-generation artificial light source, with their high luminous efficiency (LE) and color-rendering index (CRI). However, the poor stability of QDs-silicone mixture and the optical reabsorption effect between the mixed QDs/phosphor particles severely hinders the wide utilization of QDs-WLEDs. Therefore, in this paper, a silica shell was coated onto the QDs surface to solve the compatibility problem between QDs and phosphor-silicone gel. Then, a QDs-on-chip packaging structure was proposed to reduce the reabsorption energy loss. The prepared QDs@silica nanoparticles (QSNs) exhibited excellent luminescent stability over bare QDs under high-temperature (85 °C) and high-relative humidity (85% RH). With CRI > 90 and R9 > 90, the newly proposed QSNs-WLEDs demonstrated an LE enhancement of 15.7% over conventionalmixed-type WLEDs due to the less reabsorption loss. Consequently, the newly proposed QSNs-WLEDs showed 20.5 °C lower QDs working temperature under driving current of 200 mA. [ABSTRACT FROM AUTHOR]

Objectives. Social rejection is a negative social experience individuals of all ages may encounter in everyday life. It is unclear whether social rejection affects older adults more or less than younger adults. This study investigated age differences in reactions following a direct rejection and the moderating effects of cognitive resources and appraisals. Method. Eighty-three younger (18-26 years) and 53 older (60-86 years) adults engaged in an online interview during which they were either accepted or rejected seemingly by another participant. We examined participants' self-reported mood before and after the interview as well as verbal self-complexity. Results. Older adults reported greater increases in hurt feelings following rejection than younger adults. The age difference was further moderated by cognitive resources and appraisals. Among older rejected adults, those who were poorer in processing speed and those who appraised the rejection more negatively felt more hurt feelings. Older rejected adults were also rated lower in self-complexity than older accepted adults, whereas younger rejected adults and accepted adults did not differ. Discussion. The findings are largely consistent with life-span developmental theories and highlight the importance of cognitive processes when examining age differences in experiencing social rejection. [ABSTRACT FROM AUTHOR]

Photoluminescence electrospun fibers were prepared from poly(fluorinated imide)s (PFIs) solutions. The studied PFIs included three fluorinated aromatic polyimides containing naphthalene pendant groups. The maximum UV–Vis absorption spectrums of the PFI fibers were located at 300–340 nm. The photoluminescence spectra indicated that the PFI fibers exhibited the following luminescence characteristics (excitation wavelength (nm); color): 330, blue; 450, olive green; 520, red. These phenomena could be attributed to the coexistence of naphthalene unit and fluorinated groups. The nanopores surface morphology of PFI fibers were studied using scanning electron microscopy and scanning probe microscopy. Surface wettability of PFI electrospun membranes were characterized by contact angle measurement. The contact angles on the electrospun poly(aryl ether) fibers for water and glycerol were in the range of 137.7–139.0° and 139.1–142.1°, respectively. [ABSTRACT FROM AUTHOR]

A facile approach was explored to fabricate a novel magnetic hydrogel using pomegranate-like functional magnetic nanospheres (FMNs) as photoactive crosslinker and polyacrylamide as polymer matrix by photoinitiated free radical polymerization. These novel pomegranate-like FMNs were prepared by embedding Fe[sub 3]O[sub 4] nanoparticles into polystyrene by miniemulsion polymerization. The effect of FMN concentration, acrylamide monomer molar concentration, polymerization time on the magnetic properties, morphology, swelling behaviour, and dynamic mechanical properties of magnetic hydrogels were systematically investigated. Our synthetic route expands the application of these materials in the fields of smart magnetic switches, targeted drug release, biomimetic sensors, and chemical devices. [ABSTRACT FROM AUTHOR]

Human comfort has become one of the most important criteria in modern lighting architecture. Here, we proposed a tuning strategy to enhance the non-image forming photobiological effect on the human circadian rhythm based on quantum-dots-converted white light-emitting diodes (QDs-WLEDs). We introduced the limiting variability of the circadian action factor (CAF), defined as the ratio of circadian efficiency and luminous efficiency of radiation. The CAF was deeply discussed and was found to be a function of constraining the color rendering index (CRI) and correlated color temperatures. The maximum CAF variability of QDs-WLEDs was found to be dependent on the QDs’ peak wavelength and full width at half maximum. With the optimized parameters, the packaging materials were synthesized and WLEDs were packaged. Experimental results show that at CRI > 90, the maximum CAF variability can be tuned by 3.83 times (from 0.251 at 2700 K to 0.961 at 6500 K), which implies that our approach could reduce the number of tunable channels, and could achieve wider CAF variability. [ABSTRACT FROM AUTHOR]