Topological photonic crystal fibers based on second-order corner modes

Photonic crystal fibers represent one of the most active research fields in modern fiber optics. The recent advancements of topological photonics have inspired new fiber concepts and designs. Here, we demonstrate a new type of topological photonic crystal fibers based on second order photonic corner modes from the Su-Schrieffer-Heeger model. Different from previous works where the in-plane properties at $k_z=0$ have been mainly studied, we find that in the fiber configuration of $k_z>0$, a topological bandgap only exists when the propagation constant $k_z$ along the fiber axis is larger than a certain threshold and the emergent topological bandgap at large $k_z$ hosts two sets of corner fiber modes. We further investigate the propagation diagrams, propose a convenient way to tune the frequencies of the corner fiber modes within the topological bandgap and envisage multi-frequency and multi-channel transmission capabilities of this new type of fibers. Our work will not only have practical importance, but could also open a new area for fiber exploration where many existing higher-order topological photonic modes could bring exciting new opportunities for fiber designs and applications

Singlet Oxygen- and Hole-Mediated Selective Oxidation of Arylethylenes to Aryltetralones by Ag/Ag₃PO₄ under Visible Light Irradiation

Conventional semiconductor photocatalysts produce superoxide and hydroxyl radicals as the major reactive oxygen species (ROS). Here, we report that Ag/Ag3PO4 catalyst efficiently generates singlet oxygen (1O2) without other ROS under visible light irradiation. Ag/Ag3PO4 was prepared simply through photo-reduction of Ag+ under visible light irradiation. Formation of 1O2 was probed by a set of evidences such as electron spin resonance and quenching experiments. Ag/Ag3PO4 was efficient in the selective oxidation of styrenes to 4-aryltetralones with good selectivity and yield under very mild conditions without extra additives, and the photocatalyst could be facilely recycled for reuse. Mechanism studies indicate that both the photo-generated holes and 1O2 are the keys for the success of the transformation. The electron-rich surface of Ag nanoparticles and the low conduction band potential of Ag3PO4 are the reasons to produce 1O2 rather than superoxide by dioxygen activation. This is the first report on heterogeneous silver salt to produce large amounts of 1O2 at a multiphase interface under visible light irradiation

Provenance of detrital zircons in the Late Triassic Sichuan foreland basin: constraints on the evolution of the Qinling Orogen and Longmen Shan thrust-fold belt in central China

<div><p>In this article, we present <i>in situ</i> U–Pb and Lu–Hf isotope data for Upper Triassic detritus in the Sichuan region of northwestern South China, which was a foreland basin during the Late Triassic. The aim is to determine the provenance of sediments in the foreland basin and to constrain the evolution of the surrounding mountain belts. U–Pb age data for the Late Triassic detrital zircons generally show populations at 2.4–2.6 Ga, 1.7–1.9 Ga, 710–860 Ma, 410–460 Ma, and 210–300 Ma. By fitting the zircon data into the tectonic, sedimentologic, and palaeographic framework, we propose that the north Yangtze Block and South Qinling–Dabie Orogen were the important source areas of sediments in the northern part of the foreland basin, whereas the Longmen Shan thrust-fold belt was the main source region for detritus in other parts of the foreland basin. The South Qinling–Dabie Orogen could also have served as a physical barrier to block most detritus shed from the southern North China Block into the foreland basin during the sedimentation of the Xujiahe Formation. Our results also reveal that part of the flysch from the eastern margin of the Songpan–Ganzi region had been displaced into the Longmen Shan thrust-fold belt before the deposition of the foreland basin sediments. In addition, the Lu-Hf data indicate that Phanerozoic igneous rocks in central China show insignificant formation of the juvenile crust.</p></div

Fragmented Graphene Aerogel/Polydimethylsiloxane Sponges for Wearable Piezoresistive Pressure Sensors

High-performance flexible pressure sensors are critical to realizing electronic skin and wearable devices. It is the persistent pursuit of researchers to develop more sensitive flexible pressure sensors. Here, we propose a simple and effective strategy to fabricate flexible piezoresistive pressure sensors based on fragmented graphene aerogel (FGA)/polydimethylsiloxane (PDMS) sponges. Using FGA as a conductive filler and NaCl particles as a porogen and blending with PDMS, a composite material FGA@PDMS with a sponge structure was obtained. Then, the composite FGA@PDMS was dip-coated with FGA to achieve the FGA/FGA@PDMS sponge. Finally, the interdigitated electrode was printed as the bottom electrode by the screen-printing process to complete the preparation of the FGA/FGA@PDMS sensor. The results show that the fabricated flexible piezoresistive pressure sensor has higher sensitivity (0–10 kPa, 2235.84 kPa–1), good recovery, shorter response time (∼120 ms), and stable response under 1000 cycles of loading and unloading. Moreover, we investigated the applicability of the FGA/FGA@PDMS sensor as a wearable device and its application in practical sensing. Human motion detection such as arm bending, fingers, and soles of the feet shows that the sensor has good detection ability. The light-emitting-diode series circuit and the bluetooth-based wireless pressure sensor verification prototype system demonstrate the potential of the sensor for practical applications

Fragmented Graphene Aerogel/Polydimethylsiloxane Sponges for Wearable Piezoresistive Pressure Sensors

High-performance flexible pressure sensors are critical to realizing electronic skin and wearable devices. It is the persistent pursuit of researchers to develop more sensitive flexible pressure sensors. Here, we propose a simple and effective strategy to fabricate flexible piezoresistive pressure sensors based on fragmented graphene aerogel (FGA)/polydimethylsiloxane (PDMS) sponges. Using FGA as a conductive filler and NaCl particles as a porogen and blending with PDMS, a composite material FGA@PDMS with a sponge structure was obtained. Then, the composite FGA@PDMS was dip-coated with FGA to achieve the FGA/FGA@PDMS sponge. Finally, the interdigitated electrode was printed as the bottom electrode by the screen-printing process to complete the preparation of the FGA/FGA@PDMS sensor. The results show that the fabricated flexible piezoresistive pressure sensor has higher sensitivity (0–10 kPa, 2235.84 kPa–1), good recovery, shorter response time (∼120 ms), and stable response under 1000 cycles of loading and unloading. Moreover, we investigated the applicability of the FGA/FGA@PDMS sensor as a wearable device and its application in practical sensing. Human motion detection such as arm bending, fingers, and soles of the feet shows that the sensor has good detection ability. The light-emitting-diode series circuit and the bluetooth-based wireless pressure sensor verification prototype system demonstrate the potential of the sensor for practical applications

Fragmented Graphene Aerogel/Polydimethylsiloxane Sponges for Wearable Piezoresistive Pressure Sensors

High-performance flexible pressure sensors are critical to realizing electronic skin and wearable devices. It is the persistent pursuit of researchers to develop more sensitive flexible pressure sensors. Here, we propose a simple and effective strategy to fabricate flexible piezoresistive pressure sensors based on fragmented graphene aerogel (FGA)/polydimethylsiloxane (PDMS) sponges. Using FGA as a conductive filler and NaCl particles as a porogen and blending with PDMS, a composite material FGA@PDMS with a sponge structure was obtained. Then, the composite FGA@PDMS was dip-coated with FGA to achieve the FGA/FGA@PDMS sponge. Finally, the interdigitated electrode was printed as the bottom electrode by the screen-printing process to complete the preparation of the FGA/FGA@PDMS sensor. The results show that the fabricated flexible piezoresistive pressure sensor has higher sensitivity (0–10 kPa, 2235.84 kPa–1), good recovery, shorter response time (∼120 ms), and stable response under 1000 cycles of loading and unloading. Moreover, we investigated the applicability of the FGA/FGA@PDMS sensor as a wearable device and its application in practical sensing. Human motion detection such as arm bending, fingers, and soles of the feet shows that the sensor has good detection ability. The light-emitting-diode series circuit and the bluetooth-based wireless pressure sensor verification prototype system demonstrate the potential of the sensor for practical applications

Additional file 1 of Effects of Benzo[a]pyrene-DNA adducts, dietary vitamins, folate, and carotene intakes on preterm birth: a nested case–control study from the birth cohort in China

Additional file 1: Supplementary Table 1. Associations between maternal BaP-DNA adducts, dietary vitamins, folate, carotene intake preconception & during pregnancy and gestational age at delivery. Supplementary Table 2. Associations between dietary vitamins, folate, carotene intake preconception & during pregnancy and maternal BaP-DNA adducts. Supplementary Table 3. Distributions of selected characteristics between the study subjects in and not in current study

Table_1_Single and composite damage mechanisms of soil polyethylene/polyvinyl chloride microplastics to the photosynthetic performance of soybean (Glycine max [L.] merr.).docx

IntroductionAdverse impacts of soil microplastics (MPs, diameterMethodsIn this study, two widely distributed MPs, PE and PVC, were added to soils at a dose of 7% (dry soil) to examine the single and composite effects of PE-MPs and PVC-MPs on the photosynthetic performance of soybean.ResultsResults showed PE-MPs, PVC-MPs and the combination of these two contaminants increased malondialdehyde (MDA) content by 21.8-97.9%, while decreased net photosynthesis rate (Pn) by 11.5-22.4% compared to those in non-stressed plants, PVC MPs caused the most severe oxidative stress, while MPs stress resulted in Pn reduction caused by non-stomatal restriction. The reason for this is the single and composite MPs stress resulted in a 6% to 23% reduction in soybean PSII activity RCs reaction centers, along with negative effects on soybean PSII energy uptake, capture, transport, and dissipation. The presence of K-band and L-band also represents an imbalance in the number of electrons on the donor and acceptor side of PSII and a decrease in PSII energy transfer. Similarly, PVC single stress caused greater effects on soybean chloroplast PSII than PE single stress and combined stresses.DiscussionPE and PVC microplastic stress led to oxidative stress in soybean, which affected the structure and function of photosynthetic PSII in soybean, ultimately leading to a decrease in net photosynthetic rate in soybean.</p

Synergy of Organic/Inorganic and Inner/Outer Cooperative Conductive Networks in Polydimethylsiloxane-Based Porous Foam on High-Performance Flexible Sensors

The development of low-cost and high-performance flexible sensor materials is crucial for the advancement of wearable electronic devices, medical monitoring, and human–machine interfaces. In this study, a poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)-coated multiwalled carbon nanotube (MWCNT)-reinforced polydimethylsiloxane (PDMS) composite foam with a uniform organic/inorganic and inner/outer cooperative conductive network was developed to detect tensile and compressive forces. The study demonstrates that the internally cross-linked MWCNTs and PEDOT:PSS coatings within the foam framework play a crucial role in the porous structure and sensing properties of the composite foam. Due to the excellent hierarchical pore structure and dual-channel electronic pathway of the PP@MWCNTs/PDMS foam, the sensor exhibited not only high sensitivity to small pressures but also notable perception capability within the stretchable range. It also maintained excellent stability during multiple stretching and compression loading cycles. In terms of applications, the sensor could be used not only to monitor external stimuli and detect subtle movements within the human body in the field of wearable monitoring but also to sense spatial pressure distribution, which validates its potential in the development of flexible wearable sensing devices

Additional file 1: of Association of commuting mode with dyslipidemia and its components after accounting for air pollution in the working population of Beijing, China

Table S1. Summary statistics of air pollutants in urban areas in Beijing during the study period. Table S2. Risk of commuting mode for dyslipidemia, elevated TGs, reduced HDL-C, elevated TC, elevated LDL and non-HDL-C. (DOCX 18 kb