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To realize high-throughput tensile testing of miniaturized specimens, the size effect was investigated. High-throughput tensile testing was used to characterize the mechanical properties of steel in the micro-zone. Miniaturized specimens with diameters ranging from 0.7 mm to 2.5 mm were cut from low-alloyed steel and tested, and the deviations between the results of miniaturized and conventional sized specimens were examined. The results showed that the size effect was negligibly small for the tensile strength. However, the upper yield strength, lower yield strength, and plastic extension strength of miniaturized specimens decreased as the specimen diameter decreased. It was found that a diameter of 1.5 mm was critical for the tensile testing of miniaturized specimens. As the specimen diameter decreased toward 1.5 mm, the strength parameters gradually decreased, and as the specimen diameter further decreased from 1.5 mm, the strength parameters increased. In contrast, as the specimen diameter decreased from 1.3 mm, the elongation after fracture decreased. However, the percentage reduction of area did not vary between miniaturized and conventional sized specimens.

Photoinduced carriers recombine almost twice slower and diffuse 20% faster in the disordered, β-phased samples than in the ordered, γ-phased ones.

A two-dimensional 2H-ZrI2 monolayer is identified as a high-performance n-type thermoelectric material in the high-temperature regime for its favorable thermal conductivity and ultrahigh power factor.

The PDI-EH molecule was synthesized and integrated into ternary OSCs to obtain miscibility-driven morphology optimization. The relationship between the optimized morphology and charge carrier dynamics was explored by PiFM and TP-AFM characterization.

Currently, a variety of binders are developed to inhibit the rapid capacity fading of Si. The Si anodes are mainly enhanced by the chemical bonding effect on the surface of conventional solid-state binders. However, with a huge volume change of silicon, solid binders are easily deactivated. Herein, a semi-fluid binder termed GPC is designed based on a viscoelastic crosslinking network with abundant active sites and self-healing performance. The backbone of the binder network is

Large hole surrounded by a stable double-boron chain in liquid borophene.

An improved in situ sol–gel synthesis technology has successfully achieved the epitaxial growth of a single hexagonal layered α-LiAlO2 coating on the LiCoO2 surface and promotion of cycle performance at high voltage.

Oral drug delivery is a common route for management of inflammatory bowel disease (IBD) but suffers from low bioavailability and systemic side effects during passage through the alimentary canal. Here, we present a therapeutic nano reagent of a ferulic acid-derived lignin nanoparticle (FALNP). We showed that FALNP with favorable antioxidant activity can regulate IBD. More importantly, the intestinal pH-responsive degradability of FALNP allows it to withstand the harsh gastric acid environment, bypass physiological barriers, and target the intestine for gastrointestinal delivery.

To investigate the effects of salivary esterases on biostability of collagen treated by galloylated polyphenols.Human dentin was microtomed into 6-μm-thick films, which were demineralized and treated for 60 s using solutions containing 0.6% and 2% of one of the crosslinkers: tannic acid (TAC), epigallocatechin gallate (EGCG), epigallocatechin (EGC), and N-[3-dimethylaminopropyl]-N'-ethylcarbodiimide hydrochloride (EDC)/N-hydroxysuccinimide (NHS), and for 1 h using EDC/NHS. Half of the treated and untreated (control) films were subjected to human saliva incubation. Collagen biostability was assessed via exogenous protease biodegradation by weight loss and hydroxyproline release, and endogenous MMPs by in situ zymography. The degradation products of galloylated polyphenols (TAC and EGCG) by saliva were monitored using proton nuclear magnetic resonance (Collagen films treated with TAC and EGCG exhibited significantly improved biostability (p 0.05); however, the enhanced biostability was severely reduced after saliva incubation (p 0.001). For EDC/NHS treated collagen, saliva incubation showed negligible effect on the biostability.The galloyl group plays important role in collagen crosslinking, inducing higher biostability. However, galloylated polyphenols crosslinked on collagen are highly susceptible to metabolism of human saliva by salivary esterase, dramatically compromising the enhanced biostability.

Integration of metal-organic frameworks (MOFs) and flexible fabrics has been recently considered as a promising strategy applied in wearable electronic devices. We synthesized a flexible fabric-based Cu-HHTP film consisted of Cu

This study intends to discuss the mechanism of curcumin carried with poly (lactic-co-glycolic acid)-1, 2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[amino (polyethylene glycol)-2000] (PLGA-DSPE-PEG) hybridized nanoparticles on regulating the Nuclear receptor coactivator5 (NCOA5) expression, oxidative stress and level of Alfa-fetoprotein (AFP) in rats with liver cancer. Curcumin carried with PLGA-DSPE-PEG hybridized nanoparticles was prepared. These rats were divided into normal set, model set, curcumin set and set of curcumin and nanoparticles randomly. The presentation of alanine transaminase (ALT) and aspartate aminotransferase (AST) in every set was detected. The pathological change in liver tissue with hematoxylin and eosin (H&E) staining method, level of malondialdehyde (MDA) and superoxide dismutase (SOD) was detected. Presentation of AFP and NCOA5 was detected with Western Blotting assay and real-time reverse transcription–polymerase chain reaction (RT-PCR). Level of ALT, AST, MDA and AFP in normal set was the highest, but lowest in the set of curcumin and nanoparticles. The SOD presentation in the set of curcumin and nanoparticles was the highest. There was distinct surface texture, good glossiness and orderly arrangement along edge in normal set. There were grey nodular nodules, vacuole and dark-red lumps in part of live tissue in model set. There was slightly distinct liver plate texture, punctate particles and a small amount of congestion in curcumin set. There was distinct liver plate texture with orderly arrangement and a small number of inflammatory cells in set of curcumin and nanoparticles. The level of ALT and AST in rats with liver cancer was reduced by curcumin carried with PLGA-DSPE-PEG hybridized nanoparticles. The SOD activity was increased and MDA was reduced. The AFP presentation was reduced and NCOA5 expression was increased.

Electrocatalytic water splitting is an attractive way to generate hydrogen and oxygen for obtaining clean energy. Oxygen evolution reaction (OER), as one of the half reactions of oxygen evolution, is kinetically unfavorable involving the transfer of four electrons. Hydroxides are promising candidates for efficient OER electrocatalysts toward water splitting because of their high intrinsic activity and active surface area. However, quantitative prediction of hydroxide electrocatalytic performances from high-dimensional component spaces remains a challenge, severely hindering the performance-oriented precise composition and process design. Herein, we introduce a machine learning-based OER activity prediction method for hydroxide catalysts under extensive doping space for the first time. The relationship among composition, morphology, phase, pH value of the electrolyte, type of the working electrode, and overpotential was successfully fitted by the random forest algorithm. The model shows a good precision on the forecast of new experiments with a mean relative error of 4.74%. Furthermore, a new high-activity hydroxide catalyst Ni

Miniaturization of synthetic micro/nanomotors (MNMs) brings great application prospects but limits their functionalization ability. Here, we report self-fueled metal organic framework (MOF) micromotors that are endowed with capabilities of self-propulsion and antibacterial therapy by their material's intrinsic properties. The spontaneous degradation of the MOF micromotors in water would release their own constituting components of ions which act as fuels to propel themselves by ionic diffusionphoresis with a high energy conversion efficiency. Meanwhile, the metal cations released from the MOF micromotors can also serve as antibacterial reagents to kill

Sodium-Sulfur (Na-S) batteries are outstanding for their ultrahigh capacity, energy density, and low cost, but they suffer from rapid cell capacity decay and short lifespan because of serious polysulfide shuttle and sluggish redox kinetics. Herein, we synthesize thin films of covalent organic frameworks (COFs) with azobenzene side groups branched to the pore walls. The azobenzene branches deliver dual functions: (1) narrow the pore size to the sub-nanometer scale thus inhibiting the polysulfide shuttle effect and (2) act as ion-hopping sites thus promoting the Na

This study proposes a green and facile method by combining furfuryl alcohol (FA) and organic montmorillonite (OMMT) to solve the undesirable intrinsic properties and improve the performance of fast-growing wood. Wood/FA/OMMT nanocomposites (WPNCs) were fabricated by vacuum-pressure impregnation of FA/OMMT solution into wood cavities with the followingin situpolymerization to generate an interpenetrating network structure in cell structures. The FA and OMMT were distributed inside cell walls and transition areas between cell walls and cell lumens through SEM-EDXA and CLSM analyses. The resultant WPNCs had enhanced dimensional stability and water resistance ability. The incorporation of FA and OMMT could further improve the mechanical performance and the thermal stability of WPNCs. Therefore, FA/OMMT could synergistically enhance the performance of fast-growing wood.

There is a lack of scientific understanding of adding an oyster shell powder (OSP) to geopolymer concrete. The purpose of this study is: (1) to evaluate the high-temperature resistance of the alkali-activated slag ceramic powder (CP) mixture added with OSP at different temperatures, (2) to address the lack of application of environmentally friendly building materials, and (3) to reduce solid waste of OSP pollution and protect the environment. OSP replaces granulated blast furnace slag (GBFS) and CP at 10% and 20% (based on binder), respectively. The mixture was heated to 400.0, 600.0, and 800.0 °C after curing for 180 days. The results of the experiment are summarized as follows: (1) The thermogravimetric (TG) results indicated that the OSP20 samples produced more CASH gels than the control OSP0. (2) As the temperature increased, the compressive strength and ultrasonic pulse velocity (UPV) both decreased. (3) Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) results reveal that the mixture undergoes a phase transition at 800.0 °C, and compared with the control OSP0, OSP20 undergoes a different phase transition. (4) The size change and appearance image results indicate that the mixture with added OSP inhibits shrinkage, and calcium carbonate decomposes to produce off-white CaO. To sum up, adding OSP can effectively reduce the damage of high temperatures (800.0 °C) on the properties of alkali-activated binders.

Future 6G communication systems will require wideband nonreciprocal devices in the terahertz frequency domain. A novel ultra-wideband terahertz circulator is implemented by inserting a NixZn1−xFe2O4 ferrite sphere into the Al2O3 dielectric rod-array. The operating bandwidth of the circulator is broadened to 40 GHz via the external matching method through two hexagonal aluminum sheets. The three-dimensional numerical simulation suggests that the designed circulator also has an excellent insertion loss and isolation of 49.37 dB and 0.56 dB, respectively, via the finite element method. The low loss, high isolation and ultra-wideband show that the proposed scheme provides an effective path for realizing high-performance THz devices.

In this paper, general regression neural network (GRNN) with the input feature of Mel-frequency cepstrum coefficient (MFCC) is employed to automatically recognize the calls of leopard, ross, and weddell seals with widely overlapping living areas. As a feedforward network, GRNN has only one network parameter, i.e., spread factor. The recognition performance can be greatly improved by determining the spread factor based on the cross-validation method. This paper selects the audio data of the calls of the above three kinds of seals and compares the recognition performance of three machine learning models for inputting MFCC features and low-frequency analyzer and recorder (LOFAR) spectrum. The results show that at the same signal-to-noise ratio (SNR), the recognition result of the MFCC feature is better than that of the LOFAR spectrum, which is verified by statistical histogram. Compared with other models, GRNN for inputting MFCC features has better recognition performance and can still achieve effective recognition at low SNRs. Specifically, the accuracy is 97.36%, 93.44%, 92.00% and 88.38% for cases with an infinite SNR and SNR of 10, 5 and 0 dB, respectively. In particular, GRNN has the least training and testing time. Therefore, all results show that the proposed method has excellent performance for the seal call recognition.

Soft electronic devices and sensors have shown great potential for wearable and ambulatory electrophysiologic signal monitoring applications due to their light weight, ability to conform to human skin, and improved wearing comfort, and they may replace the conventional rigid electrodes and bulky recording devices widely used nowadays in clinical settings. Herein, we report an elastomeric sponge electrode that offers greatly reduced electrode-skin contact impedance, an improved signal-to-noise ratio (SNR), and is ideally suited for long-term and motion-artifact-tolerant recording of high-quality biopotential signals. The sponge electrode utilizes a porous polydimethylsiloxane sponge made from a sacrificial template of sugar cubes, and it is subsequently coated with a poly(3,4-ethylenedioxythiophene) polystyrenesulfonate (PEDOT:PSS) conductive polymer using a simple dip-coating process. The sponge electrode contains numerous micropores that greatly increase the skin-electrode contact area and help lower the contact impedance by a factor of 5.25 or 6.7 compared to planar PEDOT:PSS electrodes or gold-standard Ag/AgCl electrodes, respectively. The lowering of contact impedance resulted in high-quality electrocardiogram (ECG) and electromyogram (EMG) recordings with improved SNR. Furthermore, the porous structure also allows the sponge electrode to hold significantly more conductive gel compared to conventional planar electrodes, thereby allowing them to be used for long recording sessions with minimal signal degradation. The conductive gel absorbed into the micropores also serves as a buffer layer to help mitigate motion artifacts, which is crucial for recording on ambulatory patients. Lastly, to demonstrate its feasibility and potential for clinical usage, we have shown that the sponge electrode can be used to monitor uterine contraction activities from a patient in labor. With its low-cost fabrication, softness, and ability to record high SNR biopotential signals, the sponge electrode is a promising platform for long-term wearable health monitoring applications.

Purpose The purpose of this paper is to investigate the interfacial conductivity and corrosion resistance of the Ni–P/Ti4O7 composite coating that is deposited on a carbon steel substrate as bipolar plates for proton exchange membrane fuel cells. Design/methodology/approach The Ni–P/Ti4O7 coating was prepared by electroless plating. Scanning electron microscopy, white light interference, energy dispersive spectrometry and X-ray diffraction were used, respectively, to study the surface morphology, chemical composition and phase composition of coated samples. Electrochemical impedance spectroscopy, potentiodynamic and potentiostatic polarization were used to test the electrochemical performance and corrosion behavior. The interfacial contact resistance (ICR) was measured via the standard method. Findings The surface of the Ni–P/Ti4O7 coating is complete and dense and without obvious defects. The electrochemical test results show that the Ni–P/Ti4O7 coating provides better corrosion resistance than the Ni–P coating and substrate. Compared with the Ni–P coating, the ICR of the Ni–P/Ti4O7 coating is lower by about 82.7%. This is because the coating has more conductive contact points. The more exciting thing is that the ICR of the Ni–P/Ti4O7 coating only increases to 12.38 mΩ·cm2 after 5 h of polarization. Originality/value This paper provides a method for achieving surface modification of metal bipolar plates. Introducing Ti4O7 particles in the Ni–P layer reduces the contact resistance before and after polarization while ensuring good corrosion resistance.

Triplet excitons usually do not emit light under ambient conditions due to the spin-forbidden transition rule, thus they are called dark excitons. Herein, triplet excitons in carbon nanodots (CNDs) are brightened by embedding the CNDs into poly(vinyl alcohol) (PVA) films; flexible multicolor phosphorescence films are thus demonstrated. PVA chains can isolate the CNDs, and excited state electron or energy transfer induced triplet exciton quenching is thus reduced; while the formed hydrogen bonds between the CNDs and PVA can restrict vibration/rotation of the CNDs, thus further protecting the triplet excitons from nonradiative recombination. The lifetimes of the flexible multicolor phosphorescence films can reach 567, 1387, 726, and 311 ms, and the longest-lasting phosphorescence film can be observed by naked eyes for nearly 15 s even after bending 5000 times. The phosphorescence films can be processed into various patterns, and a dynamic optical signature concept has been proposed and demonstrated based on the phosphorescence films.

OBJECTIVES: To assess dentin collagen denaturation from phosphoric acid and enzyme treatments using collagen hybridizing peptide (CHP) and to investigate the effect of collagen denaturation on bio-stabilization promoted by proanthocyanidins (PA). METHODS: Human molars were sectioned into 7-μm-thick dentin films, demineralized, and assigned to six groups: control with/without PA modification, H(3)PO(4)-treated collagen with/without PA modification, enzyme-treated collagen with/without PA modification. PA modification involved immersing collagen films in 0.65% PA for 30 seconds. H(3)PO(4) and enzyme treatments were used to experimentally induce collagen denaturation, which was quantitated by fluorescence intensity (FI) from the fluorescently-conjugated-CHP (F-CHP) staining (n=4). FTIR was used to characterize collagen structures. All groups were subject to collagenase digestion to test the bio-stabilization effect of PA on denatured collagen using weight loss analysis and hydroxyproline assay (n=6). Data were analyzed using two-factor ANOVA and Games-Howell post hoc tests (α=0.05). RESULTS: FTIR showed collagen secondary structural changes after denaturation treatments and confirmed the incorporation and cross-linking of PA in control and treated collagen. F-CHP staining indicated high-degree, medium-degree, and low-degree collagen denaturation from H(3)PO(4)-treatment (FI=83.22), enzyme-treatment (FI=36.54), and control (FI=6.01) respectively. PA modification significantly reduced the weight loss and hydroxyproline release of all groups from digestion (p

An online automatic feedback system has been successfully installed and commissioned at the BL08U1A Soft X-ray Spectromicroscopy Beamline of Shanghai Synchrotron Radiation Facility, which can monitor the incident X-ray beam in real time by measuring the blade-edge signals of the exit slit and automatically adjust the elliptical cylindrical mirror parameters to achieve beam calibration and maintain the optimal X-ray flux of the sample. This work provides a comprehensive description of the hardware composition, system implementation, feedback logic, function and software design, system optimization and commission, as well as the online experimental results supported by the system. The experimental results demonstrated that the online automatic feedback system is capable of effectively maintaining the optimal X-ray beam flux for X-ray absorption spectroscopy experiments. Its success can provide valuable technique assistance for the design, construction and optimization of similar systems at various beamlines in synchrotron sources in the future.

Mill chatter seriously restricts the improvement of production efficiency and the development of new products. Thus, a method of cold rolling chatter monitoring and early warning is proposed based on the combination of Functional Data Analysis (FDA) and General Autoregression Model (GAM). Firstly, the multi-source cold rolling data are preprocessed by FDA to realize the smooth fitting of the unequally sampled data and the sample space is constructed based on chatter mechanism. Then, the multi-step-ahead prediction of cold rolling chatter is executed through different machine learning algorithms based on GAM, and the prediction effects of different algorithms are compared and evaluated. Finally, the maximum prediction step is defined to select the optimal algorithm, and the conclusion is drawn that Extra Tree Regression (ETR) has the best prediction effect. Therefore, the proposed method for cold rolling chatter monitoring can effectively solve the problems of delay, false alarm and distortion in prediction.