Dwarf galaxies are characterized by a very low luminosity and low mass. Because of significant accretion and ejection activity of massive black holes, some dwarf galaxies also host low-luminosity active galactic nuclei (AGNs). In a few dwarf AGNs, very long baseline interferometry (VLBI) observations have found faint non-thermal radio emission. SDSS J090613.77+561015.2 is a dwarf AGN owning an intermediate-mass black hole (IMBH) with a mass of M_BH = 3.6⁺₋₂⁵₃⁹ × 10⁵M and showing a rarely seen two-component radio structure in its radio nucleus. To further probe their nature, i.e. the IMBH jet activity, we performed additional deep observations with the European VLBI Network (EVN) at 1.66 and 4.99 GHz. We find the more diffuse emission regions and structure details. These new EVN imaging results allow us to reveal a two-sided jet morphology with a size up to about 150 mas (projected length ∼140 pc) and a radio luminosity of about 3 × 10³⁸ erg s⁻¹. The peak feature has an optically thin radio spectrum and thus more likely represents a relatively young ejecta instead of a jet base. The EVN study on SDSS J090613.77+561015.2 demonstrates the existence of episodic, relatively large-scale, and powerful IMBH jet activity in dwarf AGNs. Moreover, we collected a small sample of VLBI-detected dwarf AGNs and investigated their connections with normal AGNs. We notice that these radio sources in the dwarf AGNs tend to have steep spectra and small linear sizes, and possibly represent ejecta from scaled-down episodic jet activity.

A comprehensive review on the five levels of hierarchical structures of silk materials and the correlation with macroscopic properties/performance of the silk materials, that is, the toughness, strain-stiffening, etc., is presented. It follows that the crystalline binding force turns out to be very important in the stabilization of silk materials, while the β-crystallite networks or nanofibrils and the interactions among helical nanofibrils are two of the most essential structural elements, which to a large extent determine the macroscopic performance of various forms of silk materials. In this context, the characteristic structural factors such as the orientation, size, and density of β-crystallites are very crucial. It is revealed that the formation of these structural elements is mainly controlled by the intermolecular nucleation of β-crystallites. Consequently, the rational design and reconstruction of silk materials can be implemented by controlling the molecular nucleation via applying sheering force and seeding (i.e., with carbon nanotubes). In general, the knowledge of the correlation between hierarchical structures and performance provides an understanding of the structural reasons behind the fascinating behaviors of silk materials.

Wearable electronic textiles based on natural biocompatible/biodegradable materials have attracted great attention due to applications in health care and smart clothes. Silkworm fibers are durable, good heat conductors, insulating, and biocompatible, and are therefore regarded as excellent mediating materials for flexible electronics. In this paper, a strategy on the design and fabrication of highly flexible multimode electronic textiles (E-textile) based on functionalized silkworm fiber coiled yarns and weaving technology is presented. To achieve enhanced temperature sensing performance, a mixture of carbon nanotubes and an ionic liquid ([EMIM]Tf₂N) is embedded, which displays top sensitivity of 1.23% °C⁻¹ and stability compared with others. Furthermore, fibrous pressure sensing based on the capacitance change of each cross-point of two yarns gives rise to highly position dependent and sensitivity sensing of 0.136 kPa⁻¹. Based on weaving technologies, a unique combo textile sensor, which can sense temperature and pressure independently with a position precision of 1 mm², is obtained. The application to intelligent gloves endows the position dependent sensing of the weight, and temperature distribution sensing of the temperature.

This work demonstrates that engineering a three-dimensional photonic crystal (3DPC) structure in a highly flexible gel is a potential method to achieve flexible tactile artificial photonic skin (p-skin) for future visible-light communication (VLC). We investigated the photonic output modes of 3DPC-coated gel-based pressure sensors and explored their ability to sense low pressures (<10 kPa) through reflection. Such sensors with high sensitivity, fast response, and adjustable detection range can be fabricated in arrays of dots covering large, complex/uneven surfaces and are promising in the development of stimuli-responsive soft materials for future artificial intelligence, health monitoring, and photonic communication systems.

In this work, we demonstrate the principle of mesoscopic construction of silk fibroin (SF) hybrid materials, which endows the materials with new performance. In implementing this strategy, mediating molecules, wool keratin (WK) molecules, were adopted to in-line synthesize Au nanoparticles (WK@AuNPs), which further create the stable linkage of AuNPs with SF nanofibril networks via templated β-crystallization. Fourier transform infrared spectroscopy, X-ray diffraction, and atomic force microscopy demonstrate that the mesoscopic hybrid network structure of the hybrid materials is different from neat SF materials, which gives rise to various new performances, that is, long-stable fluorescence emission. As the fluorescence emission can be characteristically annealed by Cu ions, therefore be adopted as the highly selective ion probes. Moreover, as WK@AuNPs are homogeneously connected to SF nanofibril networks, the carbonization of the materials leads to secondary hybrid materials of carbon-Au, where nano-sized Au particles are well distributed in carbonized mesoscopic conductive carbon networks. Such hybrid materials of carbon-Au can be further fabricated into electrochemical (i.e., dopamine) sensors, which are demonstrated to have excellent sensing performance.

This work examines the self-collimation effect of silk materials on fluorescence emission/detection. A macroscopic regulation strategy, coupled with meso-reconstruction and meso-functionalization, is adopted to amplify the fluorescence emission of organic fluorescent dyes (i.e., Rhodamine 6G (R6G)) using silk photonic crystal (PC) films. The fluorescence emission can be linearly enhanced or inhibited by a PC as a result of the photonic bandgap coupling with the excitation light and/or emission light. Depending on the design of the silk fluorescence collimator, the emission can reach 49.37 times higher than the control. The silk fluorescence collimator can be applied to achieve significant benefits: for instance, as a humidity sensor, it provides good reproducibility and a sensitivity of 28.50 a.u./% relative humidity, which is 80.78 times higher than the sensitivity of the control, and as a novel curtain, it raises the energy conversion efficiency of the semitransparent dye-sensitized solar cells (DSSCs) by 16%.

Big data analytics (BDA) has increasingly attracted a strong attention of analysts, researchers and practitioners in railway transportation and engineering. This urges the necessity for a review of recent research development in this field. This survey aims to provide a comprehensive review of the recent applications of big data in the context of railway engineering and transportation by a novel taxonomy framework, proposed by Mayring (2003). The survey covers three areas of railway transportation where BDA has been applied, namely operations, maintenance and safety. Also, the level of big data analytics, types of big data models and a variety of big data techniques have been reviewed and summarized. The results of this study identify the existing research gaps and thereby directions of future research in BDA in railway transportation systems.

To examine the mechanism of the network formation of silk fibroin (SF), monodispersed colloidal particles (MDCPs) are used as well defined foreign substrates to quantify their effect on the primary nucleation of β-crystallites in molecular networks (silk nanofibrils) and the hierarchical network formation of SF. It follows that MDCPs are capable of accelerating the SF gelation by reducing the multistep nucleation barrier, which gives rise to a high density of silk fibril domain networks due to the increase of primary nucleation sites. Consequently, through governing the change in the hierarchical mesoscopic structure, the macroscopic performance of silk materials (e.g., the rheological properties of SF hydrogels and the tensile stress of fibers) can be controlled directly. As SF hydrogels represent a typical example of weak fibril domain–domain network interactions, the increase of fibril domain density leads to weaker gels. On the other hand, SF fibers correspond to strong fibril domain–domain network interactions, the increase of fibril domain density ends up with much tougher fibers. The knowledge obtained provides a facile strategy in controlling the complex hierarchical structure and macroscopic performance of SF materials, and offers useful routes for general design and functionalization of soft materials.