Preparation and sensing performance of wet-spun fabric triboelectric nanogenerator for energy harvesting.

Flexible, wearable triboelectric nanogenerators (TENGs) monitoring human movement and health signals have received more attention recently. In particular, developing a flexible TENG combining stress, strain, electrical output performance and durability becomes the current research focus. Herein, a highly stretchable, self-powered coaxial yarn TENGs were manufactured using a low-cost, efficient continuous wet-spinning method. Carbon nanotube/conductive thermoplastic polyurethane (MWCNT/CTPU) and polyvinylidene fluoride-hexafluoropropylene were utilized for the coaxial fibers conductive layers and dielectric layers, respectively. Fibers were continuously collected over a length of 10 m. Excellent electrical output with an open-circuit voltage (Voc) of 11.4 V, short-circuit current (Isc) of 114.8 nA, and short-circuit transfer charge (Qsc) of 6.1 nC was achieved. In addition, fabric TENGs with different two and three dimensional structures were further prepared by the developed coaxial fibers. The corresponding electrical output properties and practical performance were discussed. Results showed that the four-layer three-dimensional angle interlocking structure exhibited the optimal performance with an open-circuit voltage (Voc) of 38.4 V, short-circuit current (Isc) of 451.5 nA, and short-circuit transfer charge (Qsc) of 23.1 nC.

Historical sedimentary and evolutionary characteristics of POPs and EDCs in typical regions of the three Gorges reservoir, China.

The historical sedimentary and evolutionary characteristics of persistent organic pollutants and endocrine disruptors in typical regions of the Three Gorges Reservoir are scarcely studied. Herein, the 96-year data on contaminated sediment history were reconstructed using Caesium 137 isotope dating. Polychlorinated biphenyl concentrations in the involved sediment cores ranged from non-detected (ND) to 11.39 ng/g. The concentrations of polycyclic aromatic hydrocarbons ranged from ND to 2075.20 ng/g and peaked in the 1970s owing to natural, agricultural and human activities. Further, phthalate esters (PAEs) and heavy metals (HMs) were detected at concentrations ranging from ND to 589.2 ng/g and 12.10-93.67 µg/g, respectively, with highest values recorded in the 1980s owing to rapid industrialisation and insufficient management during China's early reform and development stages. PAE and HM concentrations have increased in recent years, suggesting the need to focus on industrial and agricultural activities that have caused this impact. Although current pollutant concentrations in sediments do not pose a risk to the aquatic ecosystem, they should be continuously monitored.

Species turnover and functional nestedness constitute the geographic patterns of stream diatoms in the Three Parallel Rivers region, China.

Unraveling biodiversity patterns and their driving processes is paramount in ecology and biogeography. However, there remains a limited understanding regarding the underlying mechanisms of community assembly, particularly in alpine streams where significant elevation gradients and habitat heterogeneity exist. We investigated the patterns and drivers of beta diversity, explicitly focusing on taxonomic and functional diversity, in the three parallel rivers region in China. We employed a beta diversity partitioning approach to examine the turnover and nestedness components of beta diversity and further deconstructed the diatom community into attached and unattached groups. Our results revealed distinct diversity patterns and drivers for taxonomic and functional beta diversity. Specifically, taxonomic beta diversity was mainly driven by the turnover component affected by spatial processes, whereas functional beta diversity was dominated by the nestedness component affected by environmental processes. Furthermore, our analysis of the division of the whole communities demonstrated that the varying responses of benthic diatoms with different attached abilities to environmental filtering, dispersal limitation, and directional flow were the essential reasons for shaping the biodiversity patterns of species turnover and functional nestedness in the alpine stream. Our findings suggested that partitioning beta diversity and dividing the entire community can more deeply infer underlying community assembly processes, thereby providing valuable insights into understanding biodiversity patterns, drivers, and conservation strategies.