Search

As a high-energy density material, polymeric nitrogen has attracted considerable attention, while the exceptionally high synthesis pressure hinders its studies and applications. A significant discovery indicates that the insertion of noble gas elements can effectively reduce the synthesis pressure of polymeric nitrogen compounds. This work utilized the particle swarm optimization algorithm and first-principles calculations to extensively explore the stoichiometry of Xe–N compounds under high pressures. Two phases of XeN14, P6mm and P-62m, have been discovered, which are energetically more stable than the basic mixture of Xe and N2. Evidence of charge transfer between Xe and N was found, verifying that Xe plays a crucial role in forming polymeric nitrogen compounds. These two compounds are kinetically stable at pressures ranging from 50 to 200 GPa and exhibit semiconductor properties. A unique channel-like structure was discovered in the P6mm phase. The energy densities of P6mm and P-62m phases are 7.39 and 7.59 kJ/g, respectively, significantly exceeding those of TNT (Trinitrotoluene) and HMX (Octogen), indicating their potential as high-energy density materials. [ABSTRACT FROM AUTHOR]

Mesoporous spherical cerium oxide@reduced graphene oxide (CeO2@RGO) and mesoporous spherical cerium oxide@multi-walled carbon nanotube (CeO2@MWCNT) nanocomposites were synthesized through facile hydrothermal and annealing processes, respectively. The CeO2@RGO nanocomposites (60 mg, 30 wt%), with a thickness of merely 1.39 mm, show an effective absorption bandwidth (EAB) of 6.46 GHz and a minimum reflection loss (RLmin) of −55.03 dB at 13.03 GHz (1.39 mm). Furthermore, the CeO2@MWCNT (100 mg, 30 wt%) nanocomposites show an EAB of 6.51 GHz at 1.77 mm and a RLmin surpassing −35.00 dB at 4.66 mm. The as-prepared nanocomposites were significantly better than those of previous reports. CeO2@RGO and CeO2@MWCNTs effectively enhance the electromagnetic parameters to improve the impedance match. Meanwhile, the three-dimensional conductive structure formed by the mesoporous spherical CeO2@RGO and CeO2@MWCNTs provided many reflection paths and improved the interfacial polarization and conduction loss. Furthermore, a high oxygen vacancy concentration of CeO2 in nanocomposites can promote charge polarization relaxation and lead to conductive loss. [ABSTRACT FROM AUTHOR]

Microstructures, characterized by gain, nonlinearity, internal scattering, and boundary effects, offer an exceptional platform for exploring complex optical phenomena such as random lasing, chaos, and multidimensional speckles. Specifically, complex lasers generated within microcavities and optical fibers, where strong light confinement and scattering play diverse roles, have become a significant branch of laser research. Recently, the rapid advancement of materials, micro‐nano technologies, and artificial intelligence has introduced new opportunities and challenges for the generation, control, and application of complex lasers. This review systematically examines various types of microcavity complex lasers from the perspective of microcavity structures with different degrees of disorder. It primarily focuses on the historical development, characteristics, regulation, and applications of disordered microcavity lasers and concludes with a discussion on the future trends in the development of microcavity complex lasers. [ABSTRACT FROM AUTHOR]

Color is an important visual element of high-speed train seats, which has a significant impact on passenger travel experience. In order to solve the problem that color design relies on the subjective experience of designers, this study aims to establish an effective evaluation and decision method for seat color design in a high-speed train based on the Practical Color Coordinate System (PCCS) and hybrid Kansei Engineering. Firstly, we created a series of design schemes based on the typical colors in the PCCS. Secondly, a new hybrid Kansei Engineering system was constructed; in this system, forward Kansei Engineering was constructed with Factor Analysis (FA) and Multidimensional Scaling Analysis (MDS) to analyze the cognitive feature of color sample. The Analytic Hierarchy Process (AHP) and Independent Weight Coefficient Method (IW) were used to calculate comprehensive weights, and backward Kansei Engineering was constructed with the TOPSIS to optimize and evaluate color design schemes. Finally, the design and evaluation methods were illustrated with a case. The results showed that (1) the three main influencing factors of seat color design for high-speed trains included function, aesthetics and experience, and comfort and harmony; two other potential factors included calmness and relaxation. (2) In the PCCS, warm colors have a better esthetic, while cool colors are calmer. Tones with medium brightness and saturation such as It- and Sf-tones are the optimal choice, while the V-tone is not suitable for seat color design. The effectiveness of this method is verified by a case study, which provides a reference for seat color design evaluation and optimization of high-speed trains. [ABSTRACT FROM AUTHOR]

Mn2(C2H6N6)4(NO3)4·2H2O (Mn) as one of the energetic coordination complexes was chosen for high‐pressure research. In this work, Mn was analyzed by in situ Raman scattering, infrared absorption, and synchrotron angle‐dispersive X‐ray diffraction (ADXRD) technologies up to ~20 GPa at room temperature. The vibrational modes of Mn at ambient pressure were comprehensively resolved based on the experimental results. Detailed spectral analyses revealed that Mn underwent three pressure‐induced phase transitions at 0.5, 2.5, and 5.7 GPa, respectively. ADXRD experiments confirmed the existence of these three phase transitions in Raman and infrared spectra analyses. Based on the analysis of the vibrational spectra and the changes of lattice parameters under pressure, it can be considered that the deformation of the 3‐hydrazino‐4‐amino‐1, 2, 4‐triazole (HATr) ligand led to the first phase transition, and the distortion of the triazole ring induced the second phase transition, and the rearrangement of the hydrogen bonds resulted in the third phase transition. In addition, it can be inferred from Raman spectra and ADXRD data that Mn may have experienced the abnormal expansion during the first phase transition. This work may lay the foundation for further investigating the structure and properties of energetic coordination complexes under pressure. [ABSTRACT FROM AUTHOR]

Sustainable development is an important trend for railway stations, and public facilities are essential parts of railway stations. With the sustainable development of railway station construction, the aesthetic design of public facilities is a problem that needs to be solved in the field of industrial design. In this context, this study proposed an aesthetic design and evaluation method for public facilities in railway stations. This method is constructed by combining the Kansei image and AHP (analytic hierarchy process)–FCE (fuzzy comprehensive evaluation) model, and takes the information counter at Xiong'an railway station as an example to illustrate the method. JACKTM is applied to evaluate the ergonomics of the design scheme. The results are as follows. (1) Ecological culture is an important source of Kansei images for aesthetic designs in the context of sustainable development. Kansei words, such as understated, delicate, dynamic, and others, which reflect original simplicity and original nature, are typical semantic features. Simple and smooth shapes are typical form features. (2) An aesthetic design is a system of various elements; the core content of an aesthetic design is to reflect the original aesthetic feeling. On this basis, the elements of simple, harmonious, humanized, and natural constitute the aesthetic design principle. This method is suitable for the aesthetic design and evaluation of public facilities in railway stations, which could provide valuable guidance for the aesthetic design of public facilities in railway stations under the background of sustainable development. [ABSTRACT FROM AUTHOR]

The cavity form of complex microcavity lasers predominantly relies on disordered structures, whether found in nature or artificially prepared. These structures, characterized by disorder, facilitate random lasing through the feedback effect of the cavity boundary and the internal scattering medium via various mechanisms. In this paper, we report on a random fiber laser employing a disordered scattering cladding medium affixed to the inner cladding of a hollow-core fiber. The internal flowing liquid gain establishes a stable liquid-core waveguide environment, enabling long-term directional coupling output for random laser emission. Through theoretical analysis and experimental validation, we demonstrate that controlling the disorder at the cavity boundary allows liquid-core fiber random microcavities to exhibit random lasing output with different mechanisms. This provides a broad platform for in-depth research into the generation and control of complex microcavity lasers, as well as the detection of scattered matter within micro- and nanostructures. [ABSTRACT FROM AUTHOR]