Display omitted
•Development of cathodic plasma driven self-assembly approach.•Fabrication of 3D dendrites arranged by HEAs nanoparticles.•High OER performed induced from the large surface and ...lattice deformation of electrode.
High-entropy alloys (HEAs) have been recognized as promising catalysts enabling the improvement of the sluggish kinetics of oxygen evolution reaction (OER). Nevertheless, the fabrication of nano HEAs at large-scale is still challenging. Herein, for the first time to the best of our knowledge, cathodic plasma electrolysis deposition (CPED) is utilized to develop FeCoNiMnCu HEA dendrites which are self-assembled by single HEA nanoparticles. These particles were examined to be face-centered cubic, having a size less than 40 nm and being randomly stacked together porously. The dendrites appear a 3D structure and leave a gap of approximately 5 um in between, leading to a significantly large surface area. Along with the highly deformed lattices with defects, this unique nanostructure achieves the very high efficient OER performance with an overpotential of 280 mV at 10 mA cm−2 and a low Tafel slope of 59 mV dec−1 in 1.0 M KOH solution. FeCoNiMnCu HEA dendrites also show outstanding electrochemical stability and are claimed that no compositional reorganization occurs after the long-term durability test. This work provides a new route to synthesize nanoscale HEAs for energy storage and conversion in a large-scale base for practical commercialization.
Improving bioelectrocatalytic current response of redox enzymes on electrodes has been a focus in the development of enzymatic biosensors and biofuel cells. Herein a mediatorless electroreduction of ...oxygen is effectively improved in terms of a remarkable enhancement by ca. 600% in maximum reductive current by simply adding 20% ethanol into laccase solution during its immobilization onto single-walled carbon nanotubes (SWCNTs). Conformation analysis by circular dichroism and attenuated total reflectance infrared spectroscopy demonstrate promoted laccase-SWCNTs contact by ethanol, thus leading to favorable enzyme orientation on SWCNTs. Extended investigation on acetone-, acetonitrile-, N,N-dimethylformamide (DMF)-, or dimethyl sulfoxide (DMSO)-treated laccase-SWCNTs electrodes shows a 400% and 350% current enhancement at maxima upon acetone and acetonitrile treatment, respectively, and a complete diminish of reductive current by DMF and DMSO. These results together reveal the important role of organic solvents in regulating laccase immobilization for direct bioelectrocatalysis by balancing surface wetting and protein denaturing.
The effect of ultrasound-assisted osmotic dehydration (UOD) prior to infrared drying (IR) on the drying time and quality properties of dried Pakchoi stems was studied. Results suggested that the ...ultrasound application could significantly increase the mass transfer during the osmotic process. The UOD pretreated samples showed higher relaxation times of T
23
and lower relative signal intensities of A
23
using low-field nuclear magnetic resonance (LF-NMR) analysis. Moreover, the cell structural damage and mircrochannel formation caused by the UOD pretreatment resulted in a 25 ∼ 42% reduction in drying time. Although, the chlorophyl and ascorbic acid contents of IR dried Pakchoi stems with UOD pretreatment were relatively lower in comparison with those of untreated samples, the color was better retained and the rehydration ratio was significantly improved by UOD pretreatments.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The process of gathering of scientific data plays an important role in telemonitoring and communications technologies of underwater information. However, to obtain such a huge data in ...underwater-wireless-sensor-networks, conventional methods often fail in energy efficiency. Compressive sampling (CS) provides a new perspective to solve the problem. Unfortunately, the underwater acoustic signal is non-sparse in the time domain and the current CS methods cannot be used directly. This paper adopts the discrete cosine transform-based dictionary-matrix for sparse representation. In addition, the measurement matrix is optimized via the steepest descent method for more efficient sampling. Then, we introduce an approach based on an approximated l 0 norm at the receiving terminal, to search the sparse solution via the steepest descent method and projections. Combing with the measurement matrix and dictionary-matrix, the sparse estimation is used for reconstruction. Experimental results confirm the superior performances of the strategies of the proposed compressive sampling and reconstruction than those of the traditional measurement matrix and reconstruction methods, including matching pursuit and orthogonal matching pursuit methods.
Tibet’s ancient topography and its role in climatic and biotic evolution remain speculative due to a paucity of quantitative surface-height measurements through time and space, and sparse fossil ...records. However, newly discovered fossils from a present elevation of ∼4,850 m in central Tibet improve substantially our knowledge of the ancient Tibetan environment. The 70 plant fossil taxa so far recovered include the first occurrences of several modern Asian lineages and represent a Middle Eocene (∼47 Mya) humid subtropical ecosystem. The fossils not only record the diverse composition of the ancient Tibetan biota, but also allow us to constrain the Middle Eocene land surface height in central Tibet to ∼1,500 ± 900 m, and quantify the prevailing thermal and hydrological regime. This “Shangri-La”–like ecosystem experienced monsoon seasonality with a mean annual temperature of ∼19 °C, and frosts were rare. It contained few Gondwanan taxa, yet was compositionally similar to contemporaneous floras in both North America and Europe. Our discovery quantifies a key part of Tibetan Paleogene topography and climate, and highlights the importance of Tibet in regard to the origin of modern Asian plant species and the evolution of global biodiversity.
Recently, deep learning approach, especially deep Convolutional Neural Networks (ConvNets), have achieved overwhelming accuracy with fast processing speed for image classification. Incorporating ...temporal structure with deep ConvNets for video representation becomes a fundamental problem for video content analysis. In this paper, we propose a new approach, namely Hierarchical Recurrent Neural Encoder (HRNE), to exploit temporal information of videos. Compared to recent video representation inference approaches, this paper makes the following three contributions. First, our HRNE is able to efficiently exploit video temporal structure in a longer range by reducing the length of input information flow, and compositing multiple consecutive inputs at a higher level. Second, computation operations are significantly lessened while attaining more non-linearity. Third, HRNE is able to uncover temporal tran-sitions between frame chunks with different granularities, i.e. it can model the temporal transitions between frames as well as the transitions between segments. We apply the new method to video captioning where temporal information plays a crucial role. Experiments demonstrate that our method outperforms the state-of-the-art on video captioning benchmarks.
AbstractDespite extensive investigations of bond stress versus slip modeling for RC structures, most existing bond stress–slip models are incomplete, discontinuous, and insufficiently accurate. These ...problems can cause nonconvergence and other difficulties in computational simulations of concrete structures that use bond-slip models. Through systematical analyses of an existing database of bond-slip behavior and data regressions, this work develops a unified bond stress–slip model that overcomes these difficulties and is suitable for numerical simulations. The model is given by a single and mathematically continuous equation that does not distinguish between plain and confined concrete or splitting and pullout failure because such judgments are arrived at automatically by evaluating the model parameters. Furthermore, the model outperforms the existing models in the precision of its predictions.
Celotno besedilo
Dostopno za:
DOBA, FGGLJ, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Atrial fibrillation (AF) is often asymptomatic and paroxysmal. Screening and monitoring are needed especially for people at high risk. This study sought to use camera-based remote ...photoplethysmography (rPPG) with a deep convolutional neural network (DCNN) learning model for AF detection. All participants were classified into groups of AF, normal sinus rhythm (NSR) and other abnormality based on 12-lead ECG. They then underwent facial video recording for 10 min with rPPG signals extracted and segmented into 30-s clips as inputs of the training of DCNN models. Using voting algorithm, the participant would be predicted as AF if > 50% of their rPPG segments were determined as AF rhythm by the model. Of the 453 participants (mean age, 69.3 ± 13.0 years, women, 46%), a total of 7320 segments (1969 AF, 1604 NSR & 3747others) were analyzed by DCNN models. The accuracy rate of rPPG with deep learning model for discriminating AF from NSR and other abnormalities was 90.0% and 97.1% in 30-s and 10-min recording, respectively. This contactless, camera-based rPPG technique with a deep-learning model achieved significantly high accuracy to discriminate AF from non-AF and may enable a feasible way for a large-scale screening or monitoring in the future.
The invasion ability of glioblastoma (GBM) causes tumor cells to infiltrate the surrounding brain parenchyma and leads to poor outcomes. Transient receptor potential vanilloid 4 (TRPV4) exhibits a ...remarkable role in cancer cell motility, but the contribution of TRPV4 to glioblastoma metastasis is not fully understood. Here, we reported that TRPV4 expression was significantly elevated in malignant glioma compared to normal brain and low-grade glioma, and TRPV4 expression was negatively correlated with the prognosis of glioma patients. Functionally, stimulation of TRPV4 promoted glioblastoma cell migration and invasion, and repression of TRPV4 hindered the migration and invasion of glioblastoma cells in vitro. Molecularly, TRPV4 strongly colocalized and interacted with skeletal protein-F-actin at cellular protrusions, and TRPV4 regulated the formation of invadopodia and filopodia in glioblastoma cells. Furthermore, the Cdc42/N-wasp axis mediated the effect of TRPV4-regulated cellular protrusions and invasion. Foremost, TRPV4 inhibitor treatment or downregulation of TRPV4 significantly reduced the invasion-growth of subcutaneously and intracranially transplanted glioblastoma in mice. In conclusion, the TRPV4/Cdc42/wasp signaling axis regulates cellular protrusion formation in glioblastoma cells and influences the invasion-growth phenotype of glioblastoma in vivo. TRPV4 may serve as a prognostic factor and specific therapeutic target for GBM patients.
This article describes the formation of dopamine-melanin thin films (50–200 nm thick) at an air/dopamine solution interface under static conditions. Beneath these films, spherical melanin granules ...formed in bulk liquid phase. The thickness of dopamine-melanin films at the interface relied mainly on the concentration of dopamine solution and the reaction time. A plausible mechanism underlining dopamine-melanin thin film formation was proposed based on the hydrophobicity of dopamine-melanin aggregates and the mass transport of the aggregates to the air/solution interface as a result of convective flow. The thickness of the interfacial films increased linearly with the dopamine concentration and the reaction time. The dopamine-melanin thin film and granules (formed in bulk liquid phase) with a double-layered structure were transferred onto a solid substrate to mimic the (keratin layer)/(melanin granules) structure present in bird plumage, thereby preparing full dopamine-melanin thin-film reflectors. The reflected color of the thin-film reflectors depended on the film thickness, which could be adjusted according to the dopamine concentration. The reflectance of the resulted reflectors exhibited a maximal reflectance value of 8–11%, comparable to that of bird plumage (∼11%). This study provides a useful, simple, and low-cost approach to the fabrication of biomimetic thin-film reflectors using full dopamine-melanin materials.
PDF
