Relaxor ferroelectrics exhibit outstanding dielectric, electromechanical and electrocaloric properties, and are the materials of choice for acoustic sensors, solid-state coolers, transducers and ...actuators
. Despite more than five decades of intensive study, relaxor ferroelectrics remain one of the least understood material families in ferroelectric materials and condensed matter physics
. Here, by combining X-ray diffraction, atomic force microscope infrared spectroscopy and first-principles calculations, we reveal that the relaxor behaviour of ferroelectric polymers originates from conformational disorder, completely different from classic perovskite relaxors, which are typically characterized by chemical disorder. We show that chain chirality is essential to the formation of the disordered helix conformation arising from local distortions of gauche torsional angles, which consequently give rise to relaxor properties in polymers. This study not only sheds light on the fundamental mechanisms of relaxor ferroelectrics, but also offers guidance for the discovery of new ferroelectric relaxor organic materials for flexible, scalable and biocompatible sensor and energy applications.
The synthesis of water-soluble near-infrared (NIR)-emissive fluorescent molecules with aggregation-induced emission (AIE) characteristics and theranostic functions is highly desirable but remains ...challenging. In this work, we designed and readily prepared for the first time such a molecule with AIE features, good water-solubility and intense emission in the NIR region. This AIE luminogen (AIEgen) is able to specifically "light up" the cell membrane without the involvement of a washing procedure. Interestingly, the staining process can be performed by simply shaking the culture with cells at room temperature for only a few seconds after the addition of the AIEgen, indicating an ultrafast and easy-to-operate staining protocol. This is the first fluorescent "light-up" probe for cell-imaging that allows the combination of a short staining period (at the second-level) with a wash-free process. Additionally, the presented AIEgen has also been developed to serve as an excellent phototherapeutic agent for high efficiency generation of reactive oxygen species (ROS) upon visible light irradiation, which allows its effective application in the photodynamic ablation of cancer cells, demonstrating its dual role as an imaging and phototherapeutic agent.
Exploring novel metal-metal batteries with a facile manufacturing process and low production cost is crucial for the development of next-generation energy storage systems. In this work, the ...electrochemical performance of a novel Cu–Na battery with Cu foil as a cathode and Na foil as an anode is explored for the first time. The Cu–Na battery exhibits good electrochemical reaction reversibility and cycling stability, which delivers a Coulombic efficiency of 61.5% under a charge capacity limitation of 0.02 mA h cm
− 2
with a current density of 0.01 mA cm
− 2
after 50 cycles. EIS analysis reveals that the Cu–Na battery maintains a stable electrochemical reaction resistance upon repeated cycles. The present work demonstrates that this Cu–Na battery could be a promising candidate for the next-generation energy storage system.
Graphical Abstract
In order to further investigate the grouped stud effect on the force properties of stud connectors, based on the premise that the correctness of the finite element simulation method, in this paper, a ...finite element model of grouped stud connectors was developed, and the grouped stud effect and its sensitivity factors were analyzed in order to validate the recommended formula for calculating the shear capacity of grouped stud connectors. Results show that the number of grouped stud rows and stud row spacing have a significant influence on the grouped stud effect, and the unevenness coefficient of grouped stud force is negatively correlated with the number of grouped stud rows as well as the grouped stud row spacing. Grouped stud connectors with commonly used concrete grades greater than C50 and height-to-diameter ratios of greater than 4 in steel–concrete composite structural bridges are insensitive to changes in the concrete strength grades and the length of the studs. The direction of force transmission for grouped stud changes with the change in loading angle and the unevenness coefficient of force for the grouped stud will therefore be reduced. By comparing the results of the 62 existing groups of grouped stud connectors push-out tests, the mean of the tested to calculated value ratio was found to be 1.12, the variance was 0.023, the dispersion was small, and it was shown that the recommended formula has a high degree of accuracy. The results of this paper can be used as a theoretical basis for the study of the shear stress performance of grouped stud connectors.
Lacking rapid and reliable pathogen diagnostic platforms, inadequate or delayed antimicrobial therapy could be made, which greatly threatens human life and accelerates the emergence of ...antibiotic‐resistant pathogens. In this contribution, a series of simple and reliable sensor arrays based on tetraphenylethylene (TPE) derivatives are successfully developed for detection and discrimination of pathogens. Each sensor array consists of three TPE‐based aggregation‐induced emission luminogens (AIEgens) that bear cationic ammonium group and different hydrophobic substitutions, providing tunable logP (n‐octanol/water partition coefficient) values to enable the different multivalent interactions with pathogens. On the basis of the distinctive fluorescence response produced by the diverse interaction of AIEgens with pathogens, these sensor arrays can identify different kinds of pathogens, even normal and drug‐resistant bacteria, with nearly 100% accuracy. Furthermore, blends of pathogens can also be identified accurately. The sensor arrays exhibit rapid response (about 0.5 h), high‐throughput, and easy‐to‐operate without washing steps.
A series of simple and reliable sensor arrays based on aggregation‐induced emission (AIE)‐active tetraphenylethylene derivatives are successfully developed for fast and accurate pathogen identification. Based on the distinctive fluorescence response produced by the multivalent interaction of AIE luminogens with pathogens, these sensor arrays can identify different pathogens, even normal and drug‐resistant bacteria, with nearly 100% accuracy.
Photodynamic therapy (PDT) has long been recognized to be a promising approach for cancer treatment. However, the high oxygen dependency of conventional PDT dramatically impairs its overall ...therapeutic efficacy, especially in hypoxic solid tumors. Exploration of distinctive PDT strategy involving both high‐performance less‐oxygen‐dependent photosensitizers (PSs) and prominent drug delivery system is an appealing yet significantly challenging task. Herein, a precise nuclear targeting PDT protocol based on type‐I PSs with aggregation‐induced emission (AIE) characteristics is fabricated for the first time. Of the two synthesized AIE PSs, TTFMN is demonstrated to exhibit superior AIE property and stronger type‐I reactive oxygen species (ROS) generation efficiency owing to the introduction of tetraphenylethylene and smaller singlet–triplet energy gap, respectively. With the aid of a lysosomal acid‐activated TAT‐peptide‐modified amphiphilic polymer poly(lactic acid)12k–poly(ethylene glycol)5k–succinic anhydride‐modified TAT, the corresponding TTFMN‐loaded nanoparticles accompanied with acid‐triggered nuclear targeting peculiarity can quickly accumulate in the tumor site, effectively generate type‐I ROS in the nuclear region and significantly suppress the tumor growth under white light irradiation with minimized systematic toxicity. This delicate “Good Steel Used in the Blade” tactic significantly maximizes the PDT efficacy and offers a conceptual while practical paradigm for optimized cancer treatment in further translational medicine.
A precise nuclear targeting photodynamic therapy (PDT) protocol based on tactfully designed type‐I photosensitizers with aggregation‐induced emission characteristics is fabricated for the first time with the aid of a lysosomal acid‐activated TAT‐modified nuclear delivery system, which can significantly maximize the PDT efficacy.
Amorphous FePO4/rGO composite is synthesized by a selective chemical precipitation method from the acid-leaching liquor of jarosite residue. When used as a novel anode material for lithium-ion ...batteries (LIBs), the as-prepared FePO4/rGO composite exhibits superior cyclic performance and outstanding high-rate capability in a half cell. More importantly, the full LIBs assembled with FePO4/rGO anode and commercial Li(Ni0.5Co0.2Mn0.3)O2 (NCM523) cathode still delivers a high and stable capacity of 674.9/528.7 mA h g−1 after 100/300 cycles at 0.2/0.5 A g−1, indicating the great potential of this FePO4/rGO composite as a novel high-performance anode material for LIBs. This work proposes a facile, efficient, and cost-effective strategy for the high-valued utilization of jarosite residue and provides a reference for the design and development of FePO4/rGO as a novel anode material for LIBs.
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•FePO4/rGO composite is prepared by a selective chemical precipitation method.•The leaching liquor of jarosite residue was used as the Fe source for FePO4.•FePO4/rGO composite exhibits an outstanding lithium ions storage performance.•Synergistic effect of FePO4 and rGO boosts the electrochemical performance.•The FePO4/rGO composite anode shows good performance in full LIBs.
Rational utilization of jarosite residue is significantly important from the view of environmental protection and resource recycling. Herein, we report a facile preparation of porous amorphous FePO4/reduced graphene oxide (rGO) composite by utilizing the iron resource in jarosite residue with a selective chemical precipitation method, and demonstrate its great potential as a high-performance anode material of lithium-ion batteries (LIBs). The FePO4/rGO composite exhibits superior cyclic performance (812.7 mA h g−1 over 300 cycles at 500 mA g−1) and high-rate capability (335.2 mA h g−1 even at a high current density of 10 A g−1) in a half cell. More importantly, the full LIB assembled with FePO4/rGO anode and commercial Li(Ni0.5Co0.2Mn0.3)O2 (NCM523) cathode still delivers a high and stable capacity of 674.9/528.7 mA h g−1 upon 100/300 cycles at 200/500 mA g−1, indicating the great potential of this FePO4/rGO composite as a new anode material with high lithium storage performance. This work proposes a simple, feasible, and cost-effective strategy for the high-valued utilization of jarosite residue and provides a reference for the design and development of FePO4-based anode materials for LIBs.
As the only approved Identity-Based Encryption scheme in China that is also standardized by ISO, SM9-IBE has been widely adopted in many real-world applications. However, similar to other IBE ...standard algorithms, SM9-IBE currently lacks revocation mechanism, which is vital for a real system. Worse still, we find that existing revocable techniques may not be suitable and efficient when applying to SM9-IBE. Given the widespread use of SM9-IBE, an efficient and robust user revocation mechanism becomes an urgent issue.In this work, we propose a dedicated server-aided revocation mechanism, which for the first time achieves the secure, immediate and robust user revocation for SM9-IBE. Provided with a compact system model, the proposed method leverages an existing server to perform all heavy workloads during user revocation, thus leaving no communication and computation costs for the key generation center and users. Moreover, the mechanism supports key-exposure resistance, meaning the user revocation mechanism is robust even if the revocation key leaks. We then formally define and prove the security. At last, we present theoretical comparisons and an implementation in terms of computational latency and throughput. The results indicate the efficiency and practicability of the proposed mechanism.
As a key material for capacitors, high-performance polymer dielectric films still exhibit the problem of low energy storage density, which cannot meet the requirements of high-power and ...high-temperature conditions. Here, a sandwich-structured composite film with inner layer doped TiO
2
-BCB (titanium dioxide - benzocyclobutene) and outer layer doped BN-BCB (boron nitride - benzocyclobutene) nanoparticles was prepared, which exhibits reduced dielectric loss, leakage current and enhanced dielectric constant (ε) and breakdown strength (E
b
). Diels-Alder reaction and radical polymerization reactions are utilized to form the entire cross-linked sandwich structure. Moreover, the thermal-induced crosslinked structure replaces the traditional multilayer structure established by Van der Waals forces, thus improving the dielectric and mechanical qualities of the film. Specifically, the sandwich structure composites achieved a large discharge energy density (4.0 J/cm
3
) and high charge-discharge efficiency (84%) at 150 °C and 450 MV/m, and the dielectric dissipation factor is less than 0.005. These results demonstrated that designing a cross-linked network in multilayer nanocomposite structure is a feasible method to improve the high-temperature energy storage performance of these films.
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