Enhanced triboelectric nanogenerators based on 2D smectite clay nanosheets with a strong intrinsic negative surface charge

Triboelectric nanogenerators (TENGs) have demonstrated their huge potential in micro/nano energy harvesting for self-powered systems. The output performance of TENGs is largely dependent on the surface charge density of the triboelectric materials. Here, for the first time, we propose 2D smectite clay (SC) nanosheets with a strong intrinsic negative surface charge for improving the charge density of traditional triboelectric-negative materials. A single-layer 2D SC nanosheet (∼1.1 nm thick) showed a strong negative surface potential (−14.3 mV), and the SC was confirmed to have a strong triboelectric negativity close to that of polytetrafluoroethylene (PTFE). 2D SC nanosheets were blended into polyvinylidene fluoride (SC-PVDF), based on which the SC-TENG demonstrated a significantly enhanced output performance, with the transferred charge increasing from 14 nC to 35 nC at the optimal SC concentration of 5 wt%. At higher SC concentrations, the influence of decreased effective contact area because of severe aggregation of SC nanosheets began to outperform the effect of increased interior charge. The instantaneous output power density of the SC-TENG was enormously improved to 1450 mW/m2 from that of the pristine TENG (15 mW/m2). This work proposed a new 2D material, SC, with a strong intrinsic negative surface charge, which has huge prospects in enhancing the output performance of TENGs.</p

High-performance triboelectric nanogenerators based on TPU/mica nanofiber with enhanced tribo-positivity

As a promising energy harvesting technology, triboelectric nanogenerator (TENG) has brought a leap forward to the development of self-powered systems. Many materials, especially inorganic non-metallic materials, proved to possess excellent triboelectric property, have rarely been practically used due to their fragility and rigidity. Here, fragile and rigid mica with strong triboelectric positivity is exfoliated into 2D nanosheets and electrospun into flexible and stretchable thermoplastic polyurethane (TPU) nanofibers for high-performance TENGs. Paired with polyvinylidene fluoride/MXene (PVDF/MXene) nanofibers, the transferred charge of the TENG with TPU/mica nanofibers significantly enhanced to 82.4 nC from 38.6 nC due to the enhanced tribo-positivity. Kelvin probe force microscopy (KPFM) measurements of single pure TPU and TPU/mica nanofibers showed mica apparently enhanced the positive electrostatic surface potential (ESP) of TPU. The mean peak ESP of pure TPU nanofiber was about 194 mV, while it was increased to 218 mV on the regions of TPU/mica nanofiber without mica nanosheets aggregation and 305 mV on the regions where mica nanosheets aggregated. The power density of the TENG with TPU/mica nanofiber reached 1458 mW/m2, exhibiting a 16-fold enhancement compared with the one based on pure TPU nanofiber. A thin and flexible TENG was fabricated and conformally worn on a wrist and palm for body motion monition and object gripping sorting. This work proposed high-performance triboelectric nanogenerators based on TPU/mica nanofibers and a general approach to effectively utilize rigid and fragile materials with excellent triboelectric property for making triboelectric layers.</p

Data-Efficient Image Quality Assessment with Attention-Panel Decoder

Blind Image Quality Assessment (BIQA) is a fundamental task in computer vision, which however remains unresolved due to the complex distortion conditions and diversified image contents. To confront this challenge, we in this paper propose a novel BIQA pipeline based on the Transformer architecture, which achieves an efficient quality-aware feature representation with much fewer data. More specifically, we consider the traditional fine-tuning in BIQA as an interpretation of the pre-trained model. In this way, we further introduce a Transformer decoder to refine the perceptual information of the CLS token from different perspectives. This enables our model to establish the quality-aware feature manifold efficiently while attaining a strong generalization capability. Meanwhile, inspired by the subjective evaluation behaviors of human, we introduce a novel attention panel mechanism, which improves the model performance and reduces the prediction uncertainty simultaneously. The proposed BIQA method maintains a lightweight design with only one layer of the decoder, yet extensive experiments on eight standard BIQA datasets (both synthetic and authentic) demonstrate its superior performance to the state-of-the-art BIQA methods, i.e., achieving the SRCC values of 0.875 (vs. 0.859 in LIVEC) and 0.980 (vs. 0.969 in LIVE).Comment: Accepted by AAAI 202

Association of serum levels of lipid and its novel constituents with the different stages of esophageal carcinoma

<p>Abstract</p> <p>Background</p> <p>The aim of the study was to evaluate the association of immunoglobulin G type of autoantibodies to oxidized low-density lipoprotein (oxLDL-lgG) and oxLDL-lgM with the progression of esophageal squamous cell carcinoma (ESSC).</p> <p>Methods</p> <p>Residents from Feicheng, China aged 40 to 69 years were screened for esophageal lesions in a screening program conducted during the period of January 2008 to December 2006. There were 33 controls with normal esophageal squamous epithelium cells, 37 patients with basal cell hyperplasia, 47 with esophageal squamous cell dysplasia, and 43 with ESCC. All the participants were diagnosed by biopsy and histopathological examination. Adiponectin, oxidized low-density lipoprotein (oxLDL), autoantibodies against oxLDL (oxLDL-ab), OxLDL-lgG, and OxLDL-lgM were determined by enzyme linked immunosorbent assay (ELISA). Total cholesterol, High-density lipoprotein (HDL), triglyceride, serum albumin, and blood pressure were co-estimated. Analysis of covariance for lipid levels was used to control the influence of covariates.</p> <p>Results</p> <p>The level of oxLDL-lgM increased gradually along with esophageal carcinoma progression. The oxLDL-lgM levels in the ESCC group were the highest after possible covariates were controlled. Binary logistic regression showed that oxLDL-lgM had a positive correlation with the development of esophageal carcinoma, while oxLDL and oxLDL-ab had a negative correlation with ESSC. No significant association between the levels of oxLDL-lgG and adiponectin and the different stages of ESSC was observed.</p> <p>Conclusion</p> <p>The present study shows that the decreased oxLDL and oxLDL-ab and the elevated oxLDL-lgM serum levels may relate to the development and progression of ESSC.</p

Lightweight Triboelectric Nanogenerators Based on Hollow Stellate Cellulose Films Derived from Juncus effusus L. Aerenchyma

This study reports a facile delignification and natural drying process for synthesizing cellulose films using the unique surface roughness, porosity, and lightness of the hollow stellate cellulose (HSC) united aerenchyma of the wetland weed Juncus effusus L. By controlling the grafted amino/fluorine-bearing group content of various silane coupling agents, this work successfully manipulates the triboelectric polarities of HSC films after silanization. Subsequently, a layer of Ag nanowire electrodes is coated on one side of the silanized HSC friction layers, resulting in flexible, lightweight, semi-transparent HSC-based triboelectric nanogenerators (HSC-TENGs) featuring both macro-scale surface roughness and micro-nano inner pores. These all-in-one HSC-TENGs achieve the highest output voltage of 4.86 V, which is 28 times that of TENGs employing two pristine HSC films as triboelectric layers (PHSC-TENG). Finally, the HSC-TENG with the optimum output power is applied as a wearable self-powered sensor for gait analysis, demonstrating stable and sustainable performances in distinguishing different body motions such as walking, running, jumping, and calf raising. This study not only proposes a new cellulose-based TENG for future in-depth body locomotion analysis but also paves the way for converting differently structured aerenchyma from abundant problematic aquatic or wetland weeds into promising structural templates in multifunctional cellulose-based applications.</p