High‐color‐purity emissions with small a full‐width at half‐maximum (FWHM) are an ongoing pursuit for high‐resolution displays. Though the flourishment of narrow‐band emissive materials with ...multi‐resonance induced thermally activated delayed fluorescence (MR‐TADF) in the blue region, such materials have not validated their potential in other color regions. By amplifying the influence of skeleton and peripheral units, a series of highly efficient green‐emitting MR‐TADF materials are firstly reported. Peripheral units with electron‐deficit properties can significantly narrow the energy gap for bathochromic emission without compromising the color fidelity. MR‐TADF emitters with photo‐luminance quantum yields of above 90 % with FWHMs of ≤25 nm are developed. The corresponding organic light‐emitting diodes show maximum external quantum efficiency/ power efficiency of 22.02 %/ 69.82 lm W−1 with excellent long‐term stability.
By amplifying the influence of the skeleton and peripheral acceptor units, a series of highly efficient green‐emitting MR‐TADF materials were obtained. MR‐TADF emitters with photo‐luminance quantum yields of above 90 % with full width at half maxima of ≤25 nm were realized. The corresponding organic light‐emitting diodes show maximum external quantum efficiency/ power efficiency of 22.02 %/ 69.82 lm W−1 with excellent long‐term stability.
Organic thin‐film transistors (OTFTs) can provide an effective platform to develop flexible pressure sensors in wearable electronics due to their good signal amplification function. However, it is ...particularly difficult to realize OTFT‐based pressure sensors with both low‐voltage operation and high sensitivity. Here, controllable polyelectrolyte composites based on poly(ethylene glycol) (PEG) and polyacrylic acid (PAA) are developed as a type of high‐capacitance dielectrics for flexible OTFTs and ultrasensitive pressure sensors with sub‐1 V operation. Flexible OTFTs using the PAA:PEG dielectrics show good universality and greatly enhanced electrical performance under a much smaller operating voltage of −0.7 V than those with a pristine PAA dielectric. The low‐voltage OTFTs also exhibit excellent flexibility and bending stability under various bending radii and long cycles. Flexible OTFT‐based pressure sensors with low‐voltage operation and superhigh sensitivity are demonstrated by using a suspended semiconductor/dielectric/gate structure in combination with the PAA:PEG dielectric. The sensors deliver a record high sensitivity of 452.7 kPa−1 under a low‐voltage of −0.7 V, and excellent operating stability over 5000 cycles. The OTFT sensors can be built into a wearable sensor array for spatial pressure mapping, which shows a bright potential in flexible electronics such as wearable devices and smart skins.
Flexible organic thin‐film transistors and ultrasensitive pressure sensors with sub‐1 V operation are demonstrated by using high‐capacitance polyelectrolyte composite dielectrics. Using a suspended semiconductor/dielectric/gate structure, a record high sensitivity of 452.7 kPa−1 with a low‐operating voltage of −0.7 V is achieved for the pressure sensors, which are subsequently built into a wearable sensor array for pressure mapping.
Adhesives have a long and illustrious history throughout human history. The development of synthetic polymers has highly improved adhesions in terms of their strength and environmental tolerance. As ...soft robotics, flexible electronics, and intelligent gadgets become more prevalent, adhesives with changeable adhesion capabilities will become more necessary. These adhesives should be programmable and switchable, with the ability to respond to light, electromagnetic fields, thermal, and other stimuli. These requirements necessitate novel concepts in adhesion engineering and material science. Considerable studies have been carried out to develop a wide range of adhesives. This review focuses on stimuli‐responsive material‐based adhesives, outlining current research on switchable and controlled adhesives, including design and manufacturing techniques. Finally, the potential for smart adhesives in applications, and the development of future adhesive forms are critically suggested.
In this review, the authors focused on stimuli‐responsive materials‐based adhesives, summarizing the current works of switchable and controllable adhesives, including the design and fabrication strategies. Finally, the challenges and opportunities for smart adhesives in applications and future forms of adhesives are discussed.
Multiple resonance (MR) emitters are promising for highly efficient organic light‐emitting diodes (OLEDs) with narrowband emission; however, they still face intractable challenges with ...concentration‐caused emission quenching, exciton annihilation, and spectral broadening. In this study, sterically wrapped MR dopants with a fluorescent MR core sandwiched by bulk substituents were developed to address the intractable challenges by reducing intermolecular interactions. Consequently, high photo‐luminance quantum yields of ≥90 % and small full width at half maximums (FWHMs) of ≤25 nm over a wide range of dopant concentrations (1–20 wt %) were recorded. In addition, we demonstrated that the sandwiched MR emitter can effectively suppress Dexter interaction when doped in a thermally activated delayed fluorescence sensitizer, eliminating exciton loss through dopant triplet. Within the above dopant concentration range, the optimal emitter realizes remarkably high maximum external quantum efficiencies of 36.3–37.2 %, identical small FWHMs of 24 nm, and alleviated efficiency roll‐offs in OLEDs.
Sterically wrapped multiple resonance (MR) dopants with the MR‐core sandwiched by bulk substituents have been developed to suppress molecular interactions, realizing organic light‐emitting diodes with remarkably high maximum external quantum efficiencies of 36.3–37.2 %, identical small FWHMs of 24 nm and alleviated efficiency roll‐offs over a wide range of dopant concentrations (1–20 wt %).
Most gels and elastomers introduce sacrificial bonds in the covalent network to dissipate energy. However, long‐term cyclic loading caused irreversible fatigue damage and crack propagation cannot be ...prevented. Furthermore, because of the irreversible covalent crosslinked networks, it is a huge challenge to implement reversible mechanical interlocking and reorganize the polymer segments to realize the recycling and reuse of ionogels. Here, covalent crosslinking of host materials is replaced with entanglement. The entangled microdomains are used as physical crosslinking while introducing reversible bond interactions. The interpenetrating, entangled, and elastic microdomains of linear segments and covalent‐network microspheres provide mechanical stability, eliminate stress concentration at the crack tip under load, and achieve unprecedented tear and fatigue resistance of ionogels in any load direction. Moreover, reversible entanglements and noncovalent interactions can be disentangled and recombined to achieve recycling and mechanical regeneration, and the recyclability of covalent‐network microdomains is realized.
Irreversible covalent crosslinking in the matrix polymer network is avoided. The reversible entangled microdomains of the microspheres and linear segments in tough ionogels act as elastic physical crosslinking points to provide mechanical stability, dissipate stress concentration, and prevent crack propagation in any load direction. The entangled networks can be disentangled to restore the damaged mechanical properties and realize recycling.
With the improvement of people’s living standards, the demand for books and the efficiency and accuracy of accessing books are also increasing. Because the information displayed to readers on the ...library management system is the position of the book when it is neatly arranged, sometimes the position of the book is inconsistent with the actual position of the book, which increases the difficulty for readers to find the target book. The traditional bookcase has a simple structure, and it takes a certain amount of time to search for books on weekdays. In view of the time-consuming situation of borrowing books, and in order to make it convenient for borrowers to find books, it is extremely important to develop a new type of networkable smart bookcase for libraries.
Gels that are freeze-resistant and heat-resistant and have high ultimate tensile strength are desirable in practical applications owing to their potential in designing flexible energy storage ...devices, actuators, and sensors. Here, a simple method for fabricating ionic liquid (IL)-based click-ionogels using thiol-ene click chemistry under mild condition is reported. These click-ionogels continue to exhibit excellent mechanical properties and resilience after 10,000 fatigue cycles. Moreover, due to several unique properties of ILs, these click-ionogels exhibit high ionic conductivity, transparency, and nonflammability performance over a wide temperature range (-75° to 340°C). Click-ionogel-based triboelectric nanogenerators exhibit excellent mechanical, freeze-thaw, and heat stability. These promising features of click-ionogels will promote innovative applications in flexible and safe device design.
Knowledge of somatic mutation accumulation in normal cells, which is essential for understanding cancer development and evolution, remains largely lacking. In this study, we investigated somatic ...clonal events in morphologically normal human urothelium (MNU; epithelium lining the bladder and ureter) and identified macroscopic clonal expansions. Aristolochic acid (AA), a natural herb-derived compound, was a major mutagenic driving factor in MNU. AA drastically accelerates mutation accumulation and enhances clonal expansion. Mutations in MNU were widely observed in chromatin remodeling genes such as
and
but rarely in
,
, and
mutations were found to be common in urothelial cells, regardless of whether the cells experience exogenous mutagen exposure. Copy number alterations were rare and largely confined to small-scale regions, along with copy-neutral loss of heterozygosity. Single AA-associated clones in MNU expanded to a scale of several square centimeters in size.
Surface subsidence threatens the structural stability of ground facilities located in mining-induced subsidence areas. Clarifying and evaluating the influence of surface subsidence can inform the ...construction and maintenance of various ground facilities, such as buildings, roads, and bridges. In this paper, we investigated mining-induced surface subsidence and areas of potential damage in Yangquan City, Shanxi Province, by exploiting small-baseline set interferometric synthetic aperture radar (SBAS-InSAR) monitoring and geographic information system (GIS) techniques. More specifically, we first investigated the distributions of subsidence areas and subsidence rates in Yangquan City from June 16th, 2016, to December 1st, 2016, by exploiting SBAS-InSAR monitoring. We then classified ground facilities, such as buildings, highways and railways, and identified their distributions using spatial analysis using GIS. Finally, we integrated the results of the two techniques to evaluate the potential damages induced by surface subsidence for various ground facilities. We found that, overall, (1) surface subsidence has seriously developed in the Yangquan Mine and (2) some of the subsidence areas exist in facilities with high-level restrictions, such as high-rise buildings, highways, and railways, which may cause potential damage. Our work presented in this paper could be referred to and applied to other similar cases.
Metal aromatic substances play a unique and important role in both experimental and theoretical aspects, and they have made tremendous progress in the past few decades. The new aromaticity system has ...posed a significant challenge and expansion to the concept of aromaticity. From this perspective, based on spin-polarized density functional theory (DFT) calculations, we systematically investigated the doping effects on the reduction reactions of N2O catalyzed by CO for M13@Cu42 (M = Cu, Co, Ni, Zn, Ru, Rh, Pd, Pt) core–shell clusters from aromatic-like inorganic and metal compounds. It was found that compared with the pure Cu55 cluster, the strong M–Cu bonds provide more structural stability for M13@Cu42 clusters. Electrons that transferred from the M13@Cu42 to N2O promoted the activation and dissociation of the N–O bond. Two possible reaction modes of co-adsorption (L-H) and stepwise adsorption (E-R) mechanisms over M13@Cu42 clusters were thoroughly discovered. The results showed that the exothermic phenomenon was accompanied with the decomposition process of N2O via L-H mechanisms for all of the considered M13@Cu42 clusters and via E-R mechanisms for most of the M13@Cu42 clusters. Furthermore, the rate-limiting step of the whole reactions for the M13@Cu42 clusters were examined as the CO oxidation process. Our numerical calculations suggested that the Ni13@Cu42 cluster and Co13@Cu42 clusters exhibited superior potential in the reduction reactions of N2O by CO; especially, Ni13@Cu42 clusters are highly active, with very low free energy barriers of 9.68 kcal/mol under the L-H mechanism. This work demonstrates that the transition metal core encapsulated M13@Cu42 clusters can present superior catalytic activities towards N2O reduction by CO.
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