Non-Abelian optics has emerged as a promising research field with the potential to revolutionize our understanding of light–matter interactions and enable new applications in areas including topological photonic devices, quantum computing, optical sensing, and communications. This review provides an overall framework for the rapidly developing field of non-Abelian properties in optics, including the basic concepts of non-Abelian optics, the physical mechanism of non-Abelian statistics, the non-Abelian gauge field in optics, non-Abelian braiding in optics as a special phenomenon of the non-Abelian gauge field, and current challenges and opportunities. This review is intended to provide a new perspective on non-Abelian optics, summarize the current status and advanced progress in non-Abelian gauge fields and braiding in optics, and stimulate dialog about future perspectives.
Abstract Recently, a high‐entropy strategy has attracted extensive attention and is applied to the preparation of electrode materials for energy storage batteries, aiming to improve electrochemical performance. It is found that adjusting the conformational entropy of the material can significantly enhance ion and electron transport efficiency, as well as improve the structural stability of the host material. However, there still remains a lack of deep understanding into the high‐entropy strategy, specifically regarding how this approach can alter the intrinsic properties of the material. In this work, the Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 is designed and prepared as a model material with higher entropy, and ultimately, an optimized sample of Na 3.9 Fe 2.6 V 0.1 Mn 0.1 Cu 0.1 Mg 0.1 (PO 4 ) 2 (P 2 O 7 ) is achieved. The results indicate that increasing the entropy value of the material notably enhances its crystal structure, diffusion kinetics, and interfacial stability. Consequently, this optimized sample demonstrates deep insertion/extraction of 2.8 Na + , yielding an impressively high capacity of 122.3 mAh g −1 at 0.1C, alongside an ultra‐high rate capability of 100C. Remarkably, it also sustains performance over 14 000 cycles at 50C. This study underscores a method for fabricating high‐performance electrode materials through the implementation of the entropy strategy.
Abstract Polymer fiber filters, with their high surface area, low cost, and easy large‐scale manufacturing, are widely used in air purification. These filters have been combined with various types of functional nanoparticles to endow them with electrostatic adsorption, photocatalysis, electrocatalysis, photoelectrocatalysis, or antibacterial properties, and improve their filtering performance. In this study, a summary of the research on single polymer and polymer composite filters for highly efficient air purification is presented. In single polymer filters, polar groups in the polymer chains, a rich porous structure, and electret process improve their removal capability. In polymer composite filters, metal–organic frameworks, porous particles, and electret materials as fillers improve the physical adsorption of the materials, while the use of photocatalysts, electrocatalysts, photoelectrocatalysts, and antibacterial agents as functional fillers endows the filters with additional chemical reactions for the complete degradation of gas and microorganism pollutants. Finally, the challenges that remain in the development of polymer filters for use in air purification are also discussed in terms of material type and fabrication technology. It is expected that polymer filters with tunable surface properties and multifunctions can realize highly efficient air purification with low energy consumption.
Atomically dispersed M-N-C has been considered an effective catalyst for various electrochemical reactions such as oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), which faces the challenge of increasing metal load while simultaneously maintaining catalytic performance. Herein, we put forward a strategy for boosting catalytic performances of a single Cu atom coordinated with three N atoms (CuN3) for both ORR and OER by increasing the density of connected CuN3 moieties. Our calculations first show that a single CuN3 moiety exhibiting no catalytic performance for ORR and OER can be activated by increasing the density of metal centers, which weakens the binding affinity to *OH due to the lowered d-band center of the metal atoms. These findings stimulate the further theoretical design of a two-dimensional compound of C3N3Cu with a high concentration of homogeneously distributed CuN3 moieties serving as bifunctional active sites, which demonstrates efficient catalytic performance for both ORR and OER as reflected by the overpotentials of 0.71 and 0.43 V, respectively. This work opens a new avenue for designing effective single-atom catalysts with potential applications as energy storage and conversion devices possessing high density of metal centers independent of the doping strategy and defect engineering, which deserves experimental investigation in the future.
This paper presents an optimized asymmetric three corrugation-pitch-modulated DFB laser (3CPM-DFB) with extremely high mode selectivity(△αL= 0.97) and low flatness(F = 0.009), which are two key parameters to indicate the laser’s single longitudinal mode(SLM) performance. In threshold analysis, the optimization process based on transfer matrix method is demonstrated to maximize △αL and minimize F simultaneously. In the above-threshold regime, the evolutions of △αL and longitudinal distribution of photon density with injection current are evaluated. More importantly, nanoimprint lithography which was proved an efficient way to fabricate DFB gratings can provide completely same simple fabrication procedure for both 3CPM grating and conventional uniform grating. So the big practical value of 3CPM-DFB can be expected because of its advanced performance and easy manufacturability.
NaTi2(PO4)3 (NTP) with a sodium superionic conductor three-dimensional (3D) framework is a promising anode material for sodium-ion batteries (SIBs) because of its suitable potential and stable structure. Although its 3D structure enables high Na-ion diffusivity, low electronic conductivity severely limits NTP's practical application in SIBs. Herein, we report porous NTP/C nanofibers (NTP/C-NFs) obtained via an electrospinning method. The NTP/C-NFs exhibit a high reversible capacity (120 mA h g–1 at 0.2 C) and a long cycling stability (a capacity retention of ∼93% after 700 cycles at 2 C). Furthermore, sodium-ion full cells and hybrid sodium-ion capacitors have also been successfully assembled, both of which exhibit high-rate capabilities and remarkable cycling stabilities because of the high electronic/ionic conductivity and impressive structural stability of NTP/C-NFs. The results show that the nanoscale-tailored NTP/C-NFs could deliver new insights into the design of high-performing and highly stable anode materials for room-temperature SIBs.
Laser wireless power transmission (LWPT) systems have significant applications in the field of wireless energy transmission, including spacecraft sensor networks, satellite-to-satellite communication, and remote power supply. However, continuous laser exposure increases the temperature of the photovoltaic (PV) cells in the LWPT system, thus decreasing the electrical output performance. This work, which we believe is a new approach, is on the basis of a notch film designed by a combined merit function proposed to maintain the electrical output performance while under 1064-nm continuous laser irradiation. Moreover, the thermal stability of PV cells under laser irradiation was investigated, which revealed the recoverability of the open-circuit voltage (Voc) of the cells at different temperatures, and the thermal damage to cells was a gradual process. This process began with the vaporization of the encapsulation adhesive, followed by a decline in, but still recoverable and functional, electrical performance, and finally, the cell was completely damaged. The thermal stability of the PV cells coated with the notch film increased ten-fold compared to those without it. Furthermore, the correlation between the minimum Voc and maximum temperature of the cells with notch films of different performances was established. These investigations serve as references for further optimization of LWPT.
In recent years, inhibition of photoinduced electron and hole recombination is considered as a breakthrough to improve the photocatalytic degradation of pollutants. In this study, we successfully loaded ZnFe 2 O 4 (ZFO) microsphere onto BiFeO 3 (BFO) microcubes by a simple hydrothermal method. Under the effect of heterojunction between BFO and ZFO, the recombination rate of electron and hole was decreased significantly, leading to the enhanced photocatalytic effect. Morphology analysis shows that ZFO and BFO interface are closely combined. The photocatalytic experiments show that the degradation efficiency of tetracycline and methylene blue by BFO/ZFO-10% composites are 1.63 and 1.38 times higher than that of pure BFO. In addition, four cycles of experiments also proved that BFO/ZFO-10% has good stability and excellent magnetic properties, making the sample easy to be recovered. A possible electron hole transfer path on the base of a direct Z-scheme mechanism was proposed. This study provides a useful guide toward the design of the highly efficient and magnetic collectable photocatalysts by the introduction of magnetic component and the construction of heterojunction, and as-synthesized BFO/ZFO was proved to be a promising photocatalyst for the elimination of toxic organic molecules in groundwater.
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