Search

Intelligent diagnostic algorithms based on convolutional neural networks (CNNs) have shown great potential in diagnosing various conditions. However, accurately and robustly diagnosing faults in noisy situations remains challenging. This study presents an adaptive fully convolutional network (AFCN) for identifying bearing defects in noisy environments. First, we use a novel large kernel convolution method for high-frequency noise reduction and wide-area temporal feature extraction. By utilizing a sequence of stacked residual adaptive convolution blocks, the AFCN achieves a selective emphasis on significant features and adaptive adjustment of feature weights at various convolution scales. The experimental results have shown that the AFCN achieves a diagnostic accuracy of over 90% for the faults in the CWRU dataset under the −8 dB noise and over 77% for the PU dataset in the case of −6 dB noise. The comparison results with five advanced baseline models have demonstrated the superiority of the AFCN in feature extraction, noise immunity, and robustness to the noise environment. The AFCN provides a better adaption to noise interference than conventional CNNs and other advanced adaptive networks. [ABSTRACT FROM AUTHOR]

With the advent of energy crisis and stringent emission regulations, natural gas (NG)/diesel dual‐fuel engines have entered the popular view. In this paper, the accurate boundary conditions are determined by the Converge model and the transient parameters were introduced into the chemical kinetics model to make the operating conditions more closely match the actual engine operating conditions. The effects of different methane/n‐heptane ratios, initial temperatures, initial pressures, and equivalence ratios on the IDT of methane/n‐heptane fuel mixtures were analyzed using comprehensive chemical kinetic tools such as mole fraction analysis, ROP analysis, and sensitivity analysis. The IDT of methane/n‐heptane mixture decreased significantly with increasing the equivalence ratio, initial pressure, and the proportion of n‐heptane in the mixture, but the change of temperature was more complicated for the IDT. The NTC behavior of methane/n‐heptane mixture was also affected by the NTC behavior of n‐heptane. With the increase of initial temperature, the consumption of methane and n‐heptane appeared to be significantly accelerated. The peak of radicals and intermediate groups appeared earliest and had the highest radical concentration when the n‐heptane content was 30%. With the increase of initial pressure, the peak moments of the six radicals were further advanced, but the mole concentrations of O, OH, H radicals decreased significantly. This paper not only provides a reference for the design of NG/diesel dual‐fuel engines, but also provides a theoretical basis and data support for improving the ignition and initial condition setting strategies of the engines. [ABSTRACT FROM AUTHOR]

With the rapid development of road networks, various traffic safety issues have become endless. To solve the problems, a multi‐mode triboelectric nanogenerator(M‐TENG) composed of roller‐based TENG, turnplate‐based TENG, and vertical separation‐based TENG is proposed. The M‐TENG can be applied to harvest the wind energy and mechanical vibrational energy generated by moving vehicles on ordinary roads or roads beside bridges to provide power for traffic warning devices and signal sensors. In terms of wind energy harvesting, the M‐TENG shows an excellent wind energy conversion capability. For vibrational energy harvesting, the M‐TENG can respond well to the frequency range (1–40 Hz) of bridge vibration in an actual environment and produce a good output. Thus, due to the above excellent outputs, the M‐TENG can successfully power caution lights and commercial LED strips, achieving a good warning effect. Additionally, the M‐TENG also can send RF signals after charging the energy management unit circuit for 5 min when simulating a natural environment. Based on the aforementioned wide applications, the M‐TENG not only demonstrates its excellent energy harvesting capability but also shows that it has huge potential in the field of transportation. [ABSTRACT FROM AUTHOR]

Although triboelectric nanogenerators (TENGs) are highly efficient and adaptable in harvesting ocean wave energy, the dynamics of floating TENGs in underwater wave stimulations have so far rarely been studied. Herein, the interactions between centimeter‐scaled floating structures and water waves are experimentally revealed. By integrating inertial measurement units into the shells of various floating TENG structures, the primary acceleration data associated with different parameters are obtained. Based on the data of 63 literature reported floating TENGs, a series of experimental parameters are elaborately probed, including shell shape, shell size, weight, barycenter, wave strength/frequency, and wave‐producing methods. Through dynamic calculations, each can offer the kernel data of acceleration and frequency distribution curves, revealing several regularities in water–structure interactions associated with TENGs. These calculations could serve as guidance for the design of the future floating TENGs in blue energy harvesting. [ABSTRACT FROM AUTHOR]

The recent local measurements of the Hubble constant H 0 , indicate a significant discrepancy of over 5 σ compared to the value inferred from Planck observations of the cosmic microwave background (CMB). In this paper, we try to test the standard cosmological model ΛCDM by testing the consistency of early and late cosmological parameters in the same observed data. In practice, we simultaneously derive the early and late parameters using baryon acoustic oscillation (BAO) measurements, which provide both low and high-redshift information. CMB data are also included in the analysis as a "distance prior", which tracks the same BAO feature and resolve parameter degeneracy. By using the parameter ω m = Ω m h 2 , we introduce ratio (ω m) , defined as the ratio of ω m which are constrained from high and low-redshift measurements respectively, to quantify the consistency between early and late parameters. We obtained a value of ratio (ω m) = 1.0069 ± 0.0070 , indicating there is no tension between early parameters and late parameters in the framework of ΛCDM model. As a result, our test does not expose the defects of the ΛCDM model. In addition, we forecast the future BAO measurements of ratio (ω m) , using several galaxy redshift surveys and 21 cm intensity mapping surveys, and find that these measurements can significantly improve the precision of cosmological parameters. [ABSTRACT FROM AUTHOR]

• Cold starting process of diesel engine at low temperature is analyzed in detail. • An improved thermodynamic model of diesel engine is developed. • Cold starting performance of diesel engine is validated by the experimental results. • Suggestions for cold starting performance enhancement of the diesel engine are proposed. It is very important for the diesel engine to achieve a cold startup at low environmental temperature especially in the region with the temperature in the range of −40 °C to 0 °C. Thus, the specific cold start characteristics, such as gas leakage, heat loss and clearance volume, should be investigated in detail. In order to investigate the cold start ability, an improved thermodynamic model for thermodynamic parameters is developed. The prediction of ignition temperature is the closest to the experimental values when the adiabatic index is equal to 1.34 for the compressed gas. The thermodynamic results show that the compression pressure is the most sensitive to the gas leakage rate , followed by the heat transfer loss rate and reference clearance volume. The gas leakage, heat loss and clearance volume are employed to investigate the cold start ability for the diesel engine, which provide a better reference for strengthening the cold start capacity research. The small clearance volume and big initial intake air temperature can improve the exergy of diesel engine. In addition, the entropy production increases with the increase of clearance volume. Similarly, the exergy of system will reduce with the increase of entropy production. Finally, the improvement suggestions for cold starting performance enhancement of the diesel engine are proposed. [ABSTRACT FROM AUTHOR]

• Lift coefficient and the drag coefficient of the concentrator are investigated. • Stability criterion based on the lift-drag ratio is proposed by the bifurcation point set. • Rationality of the method is verified by the pitch moment coefficient and maximum stress. In order to solve the problem about determination of stability of dish solar concentrator system, a computational fluid dynamics software STAR-CCM+ is used to investigate the lift coefficient and the drag coefficient of the concentrator under different wind attack angles and height angles. Based on the simulation results of the lift coefficient and the drag coefficient of the concentrator, some main steps to can be expressed as follows: (1) A mechanical model of dish solar concentrator system under different wind attack angles and height angles is established and the moment equation of the dish solar concentrator is used as a potential function to establish the cusp catastrophe model of instability of a dish solar concentrator. The stability criterion based on the lift-drag ratio K ld is proposed based on the bifurcation point set. If −1.54 < K ld < 1.54, the system is stable. If K ld = ±1.54, the system is critically stable. If K ld < −1.54 or K ld > 1.54, the system is unstable. (2) The stability of dish solar concentrator system is determined, and the critical stability state of the dish solar concentrator system is achieved. The rationality of the method is verified by the pitch moment coefficient. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • A dish concentrator model is developed by two coupling software. • Finite element model is used to predict the amplitude and frequency of the vibration. • Fluid-structure coupling model is used to analyze harmonic response. • The maximum deformation of reflector is analyzed. • The modal analysis is performed by the fluid-structure coupling model. Abstract The dish solar thermal power generation system is widely used due to the high efficiency. The mechanism of the whole system must meet stringent structural deformation requirements. In this work, the dish concentrator model is developed by the CFD software STAR-CCM+ and the finite element software of ABAQUS, respectively. The pressure fields obtained in the STAR-CCM+ environment are mapped to the ABAQUS model. The validated finite element (FE) model is employed to predict the amplitude and frequency of the vibration. The effects of different pitch angle, azimuth angle and wind velocity on the amplitude and frequency of the vibration are also considered in the process of calculation. The simulated calculation of fluid-structure coupling model is used for the analysis of harmonic response of four hinge nodes vibration. The vibration period of sinusoidal wind excited is 2 s. The results show that the vibration of the dish concentrator will occur with the sinusoidal wind load and reaches the maximum in a short time, then gradually becomes flatter. Moreover, the change of the height angle has a little influence on the modal frequencies of the system and the modal natural frequency is only changed a little when the wind load increases. Thus, the information obtained from the FE model can serve as a reference for subsequent analyses mechanism design such as wind-induced response dynamics analysis. [ABSTRACT FROM AUTHOR]

Wireless electric energy transmission is an important energy supply technology. However, most wireless energy supply based on electromagnetic induction cannot be used for energy transmission through a metal chamber. Herein, a novel idea for wireless electric energy transmission through various isolated solid media based on triboelectric nanogenerator (TENG) is presented. The electric energy is first transformed into mechanical vibration energy in mechanical wave that can propagate well in solid medium, and then the vibration energy is harvested by a TENG. By employing the spring steel sheets and freestanding triboelectric-layer structure, the vibration TENG as an energy conversion unit has the advantages of high efficiency and facilitation, boosting this wireless energy transmission technology to be an alternative way of delivering electric energy through metal medium. The working principle and output performance have been systematically studied. A commercial capacitor can be charged from 0 to 10 V in 33 and 86 s isolated by an acrylic plate and a copper plate in thickness of 3 mm, respectively. The wireless electric transmission technology is also applied to deliver electric energy into a vacuum glove box and across glass wall successfully. This novel technology has great potential applications in implantable microelectronic devices, encrypted wireless communication, and even nondestructive testing. [ABSTRACT FROM AUTHOR]

Introduction: The obstruction of the urinary tract by calculi at the narrowest anatomical areas leads to impaired drainage and severe pain. The aim of this study was to evaluate a new technology, extracorporeal physical vibrational lithecbole (EPVL) combined with tamsulosin, as a treatment for distal ureteral calculi (DUC). Materials and Methods: Between July 2013 and July 2014, 672 patients diagnosed withDUCwere randomly divided into three groups; a group receiving EPVL plus 0.4mg oral tamsulosin daily (PO qd) (experimental group, n = 236), a group receiving 0.4mg tamsulosin PO qd (n = 222), and a group receiving EPVL only (n = 214) (control groups). Results: There were no significant differences in general characteristics between the three groups. Stone diameters ranged from 0.32 to 1 cm. In the EPVL plus tamsulosin group, 60.1% of patients showed detectable fragment expulsion at 48 hours, and 91.1% were stone free at 7 days. Compared with the two control groups, these rates were significantly higher (EPVL group was 0% and 50.5% and medical expulsive therapy group was 0% and 50.0%, p < 0.05). The stone-free rates were similar in the three groups 2 weeks later (94.5%, 93.6%, and 93.5%; p > 0.05). Patients in the EPVL plus tamsulosin group achieved similar stone-free rates compared with the other two groups, but the speed of the stone expulsion was quicker for both sexes and all age groups (about a week; p < 0.05). Conclusion: This indicates that EPVL plus tamsulosin could be used as an effective, but faster treatment option for patients with DUC, alleviating the symptoms of DUC in a shorter period of time. [ABSTRACT FROM AUTHOR]

Rocks are natural materials with a heterogeneous microstructure, and the heterogeneity of the microstructure plays a crucial role in the evolution of microcracks during the compression process. A numerical model of a rock with a heterogeneous structure under compression is developed by digital image processing techniques and the discrete element method. On the grain scale, the damage mechanism and microcrack characteristics of a heterogeneous Biotite granite under compression fracture are investigated. First, the process of constructing a digital image-based heterogeneous grain model is described. The microscopic characteristics of geometric heterogeneity, elastic heterogeneity, and contact heterogeneity are all considered in the numerical model. Then, the model is calibrated according to the macroscopic properties of biotite granite obtained in the laboratory, and the numerically simulated microcrack cracking processes and damage modes are obtained with a high degree of agreement compared to the experiments. Numerical simulations have shown the following: (1) Microcracking occurs first at the weak side of the grain boundaries, and the appearance of intragranular shear cracks indicates that the rock has reached its peak strength. (2) The stress concentration caused by the heterogeneity of the microstructure is an essential factor that causes rock cracks and induces rupture. Intragranular cracks occur successively in quartz, feldspar (plagioclase), and biotite, with far more intragranular cracks in quartz and feldspar (plagioclase) than in biotite. (3) Microcracking in quartz occurs as clusters, fork and fracture features, and in feldspar (plagioclase) it tends to cause penetration microcracking, which usually surrounds or terminates at the biotite. (4) As the confining pressure increases, the tensile break between the grains is suppressed and the number of shear cracks increases. At the macro level, the rock failure mode of the numerical model changes from split damage to shear destruction, which is consistent with the law shown in laboratory experiments. [ABSTRACT FROM AUTHOR]

Medication recommendation (MR) is a promising task that benefits both patients and medical practitioners. However, the individual differences in patients and drug–drug interactions (DDIs) in medication combinations are two key factors that severely limit the personalization and safety of the present MR models. To alleviate the challenges mentioned above, this paper proposes a novel MR model named Trans-GAHNet, which innovatively leverages transformer-based representation learning and constructs multiple graphs for drug information augmentation. More specifically, the transformer network architecture is deployed to fully encode the sequential EHR data for effective patient representations, which addresses the cold start issue and enhances the interpretability of representation learning. Next, multiple graphs are employed to capture the co-occurrence and exclusiveness in drug pairs and to mitigate potential DDIs in drug combinations, thereby enhancing the personalization and safety of the predicted medication combinations. Finally, extensive experiments on real-world datasets are conducted to evaluate the proposed model, and the experimental results demonstrate that Trans-GAHNet outperforms the state-of-the-art baseline models on multiple metrics, with Jaccard, F1 and PRAUC scores of 0.5238, 0.6786 and 0.7795, respectively. • The transformer architecture is deployed to encode the sequential EHR data. • Multiple graphs are employed to capture the co-occurrence and exclusiveness in drug pairs. • The Trans-GAHnet model is more suitable for medication recommendation than the baselines. [ABSTRACT FROM AUTHOR]

Triboelectric nanogenerators (TENGs) have emerged as a promising technology for harvesting wave energy and converting it into electrical power. However, the practical application of TENGs in real-world ocean environments has been hindered by a lack of comprehensive data on their hydrodynamic responses and output properties under realistic wave-flow conditions. This gap in the literature has limited our understanding of how to optimize TENG designs for efficient wave energy conversion. In this study, a comprehensive series of experiments were conducted using a large wave-flow flume to investigate the performance of a flower-like TENG (FL-TENG) under various hydrodynamic conditions, including wave height, wave frequency, flow velocity, and structural geometry. The output voltage, motion responses, and cable tension of the FL-TENG were monitored using an electrometer, a machine vision-based displacement measurement system, and tensiometers, respectively. The results show that the relationship between the incident wave-flow area and the FL-TENG's output properties is more complex than a simple "bigger is better" trend. It is also found that the output voltage and hydrodynamic responses of the FL-TENG were positively correlated with the aspect ratio of the rectangular incident wave-flow shape. Importantly, the presence of water flow was observed to significantly inhibit the output properties and hydrodynamic responses of the FL-TENG. These findings provide valuable insights and new design considerations for advancing TENG applications in real-world ocean environments, ultimately contributing to the development of more efficient wave energy conversion technologies. [ABSTRACT FROM AUTHOR]

The integration of triboelectric nanogenerator (TENG) with electromagnetic generator (EMG) holds promise for the efficient harvesting of broadband wind energy, yet the challenge of coupling these two systems into one high‐durability unit has persisted. Herein, a novel magnetic attraction coupling principle is proposed to enable seamless switching between TENG unit and EMG unit across varying rotation speeds without the need for additional mechanical components, thereby enhancing the energy harvesting efficiency of the magnetotropic hybrid generator (MHG). The rotating magnetic field induces the Si‐Mn steel plates to operate in a contact‐separation mode within a compact space, producing a 270 V open‐circuit voltage output, while the excess magnetic flux is captured by coils to generate an induced current of 5 mA. Most importantly, the overall structure is free from mechanical wear, maintaining consistent performance after 130 000 cycles. The harvested wind energy by MHG is utilized to power human infrared sensors, flame sensors, and Bluetooth hygrometers, providing a long‐term, stable power supply for forest fire early warning systems. This study pioneers a novel and robust mechanism that effectively combines TENG and EMG using magnetotropic property, opening a new avenue for efficiently harvesting wide‐band mechanical energy. [ABSTRACT FROM AUTHOR]

The cracking of rock mass under compression is the main factor causing structural failure. Therefore, it is very crucial to establish a rock damage evolution model to investigate the crack development process and reveal the failure and instability mechanism of rock under load. In this study, four different strength types of rock samples from hard to weak were selected, and the Voronoi method was used to perform and analyze uniaxial compression tests and the fracture process. The change characteristics of the number, angle, and length of cracks in the process of rock failure and instability were obtained. Three laws of crack development, damage evolution, and energy evolution were analyzed. The main conclusions are as follows. (1) The rock's initial damage is mainly caused by tensile cracks, and the rapid growth of shear cracks after exceeding the damage threshold indicates that the rock is about to be a failure. The development of micro-cracks is mainly concentrated on the diagonal of the rock sample and gradually expands to the middle along the two ends of the diagonal. (2) The identification point of failure precursor information in Acoustic Emission (AE) can effectively provide a safety warning for the development of rock fracture. (3) The uniaxial compression damage constitutive equation of the rock sample with the crack length as the parameter is established, which can better reflect the damage evolution characteristics of the rock sample. (4) Tensile crack requires low energy consumption and energy dispersion is not concentrated. The damage is not apparent. Shear cracks are concentrated and consume a large amount of energy, resulting in strong damage and making it easy to form macro-cracks. [ABSTRACT FROM AUTHOR]

Triboelectric nanogenerators (TENGs) have recently emerged as a promising technology for efficient water wave energy harvesting. However, there is a paucity of clear guidance regarding the optimal designs of TENGs and their shells to achieve efficient absorption and conversion of water wave energy in real random waves. Herein, from the perspective of wave‐body interaction and energy transfer, this paper proposes a structural quality factor (Qunit) for the quantitative evaluation of both the motion of floating triboelectric nanogenerator (Flo‐TENG) shells and their capability to absorb and convert water wave energy efficiently. The factor is further subdivided into the amplitude structural quality factor (Qacc), which characterizes shell motion amplitude, and the frequency structural quality factor (Qf), which describes shell motion frequency. This paper systematically investigates the impact of various shell parameters such as bow shapes, curvatures, inclinations, and immersion ratios on Qacc and Qf. The findings indicate that variations in shell shape result in distinct Qunit values along different axial directions of wave propagation. These variations directly influence energy absorption efficiency in these directions. These results provide fundamental guidance for the design of high‐performance Flo‐TENG shells and the selection of internal energy harvesting directions to enable more efficient energy conversion. [ABSTRACT FROM AUTHOR]

Triboelectric nanogenerators (TENGs) are effective in harvesting high‐entropy low‐frequency wave energy, yet traditional TENGs struggle to align with the meter‐scale wavelengths prevalent in marine environments, significantly impairing their wave energy conversion efficiency. Addressing this, the One Meter TENG (OM‐TENG) is introduced, a pioneering advancement in TENG design that extends the shell size to 1 m. This innovation features a novel lantern‐shaped stacked silicon‐manganese steel sheet configuration, optimizing internal space usage, and achieving a single‐cycle transfer charge of 60.82 µC and a friction layer area density of 1.76 cm−1. Furthermore, by integrating a segmented limiter device for rational control of different sliders, effective contact separation among numerous TENG units is realized. Comprehensive evaluations through theoretical analysis, multiphysics field numerical simulations, sensor data analytics, and comparative experimental measurements have unequivocally demonstrated OM‐TENG's superior capability in capturing meter‐scale wave energy under actual environmental conditions, alongside its remarkable anti‐capsize performance. Achieving peak outputs of 584 V and 444 µA, OM‐TENG can power 96 2 W LEDs and drive wireless communication modules, marking a significant step forward in the efficient utilization of wave energy and the design of large‐scale TENGs. [ABSTRACT FROM AUTHOR]

Deploying triboelectric nanogenerator (TENG) units on and below the water surface has been a conventional method for harvesting wave energy. However, this approach restricts the TENG's amplitude to that of the water waves, limiting the actual offshore output. Here, a new method of placing TENG units above the water surface using a wave amplitude amplifier is reported. This addresses the issue of insufficient amplitude in traditional wave energy TENGs and achieves higher electrical output performance in real offshore conditions. Moreover, the innovative four‐helix TENG (FH‐TENG), designed with special pattern cutting and bridging techniques, eliminates the need for internal wires, foundational frameworks, and counterweights. Results show that FH‐TENG placed on the amplitude amplifier achieves over a 76% increase in amplitude and a 235% enhancement in charge output compared to FH‐TENG floating directly on the water surface, and the maximum output voltage, transferred charge and output current reach 246 V, 7.9 µC, and 156.1 µA, respectively. Importantly, when deployed in real marine environments, this system generates more electric energy than in a lab pool under the same peak wave height, providing a reliable power supply solution. This work establishes a precedent for deploying lightweight wave energy TENGs above the water surface. [ABSTRACT FROM AUTHOR]

Triboelectric nanogenerators (TENGs) provide one of the most promising techniques for large‐scale blue energy harvesting. However, lack of reasonable designs has largely hindered TENG from harvesting energy from both rough and tranquil seas. In this paper, an oblate spheroidal TENG assembled by two novel TENG parts is elaborately designed for both situations. The TENG in the upper part is based on spring steel plates without other substrate materials, which makes it possible to output considerable power in rough seas and occupy small space. The TENG in the lower part consists of two copper‐coated polymer films and a rolling ball which can capture small wave energy from tranquil seas. The working mechanism and output performance are systematically studied. A maximum open‐circuit voltage of 281 V and a short‐circuit current of 76 µA can be achieved by one upper part, enough to charge a commercial capacitor for potential applications. More important, the proposed oblate spheroidal shell not only guarantees high sensitivity of the TENG in the lower part, but also qualifies the TENG with unique self‐stabilization and low consumables for the next generation of TENGs with new structural design toward all‐weather blue energy harvesting. [ABSTRACT FROM AUTHOR]

Innovative functional electrical stimulation has demonstrated effectiveness in enhancing daily walking and rehabilitating stroke patients with foot drop. However, its lack of precision in stimulating timing, individual adaptivity, and bilateral symmetry, resulted in diminished clinical efficacy. Therefore, a closed‐loop wearable device network of intrinsically controlled functional electrical stimulation (CI‐FES) system is proposed, which utilizes the personal surface myoelectricity, derived from the intrinsic neuro signal, as the switch to activate/deactivate the stimulation on the affected side. Simultaneously, it decodes the myoelectricity signal of the patient's healthy side to adjust the stimulation intensity, forming an intrinsically controlled loop with the inertial measurement units. With CI‐FES assistance, patients' walking ability significantly improved, evidenced by the shift in ankle joint angle mean and variance from 105.53° and 28.84 to 102.81° and 17.71, and the oxyhemoglobin concentration tested by the functional near‐infrared spectroscopy. In long‐term CI‐FES‐assisted clinical testing, the discriminability in machine learning classification between patients and healthy individuals gradually decreased from 100% to 92.5%, suggesting a remarkable recovery tendency, further substantiated by performance on the functional movement scales. The developed CI‐FES system is crucial for contralateral‐hemiplegic stroke recovery, paving the way for future closed‐loop stimulation systems in stroke rehabilitation is anticipated. [ABSTRACT FROM AUTHOR]

In this study, Al–20Si alloy is modified by appending trace Sr–Sc–Ce nanoparticles and ultrasonic vibration processing (UVP). The consequences indicate that its microstructure is significantly refined and its mechanical characteristics are improved. The effect of the favorable refinements is achieved by appending 0.2% Sr–0.15% Sc–0.3% Ce and performing UVP. The primary Si is the minimum, the grain roundness coefficient and the strength of extension are the maximum, and the spheroidizing effect of α‐Al is the best. The elongation and hardness are the highest when 0.4% Ce is appended. The research consequences afford a reasonable process scheme for manufacturing high‐quality wear‐resistant material of the automotive and aerospace industries. [ABSTRACT FROM AUTHOR]

Although natural evaporation absorbs substantial thermal energy from the ambient environment, efficiently utilizing this high‐entropy energy remains challenging. Here, the first water evaporation‐induced triboelectric nanogenerator is proposed. It only uses tap water to harvest low‐grade heat energy from the surroundings to convert it into electricity. The natural evaporation of the liquid can generate unintermittent electricity with an open‐circuit voltage of 382 V, a peak power of 0.42 mW, and three orders of magnitude enhancement up to 59.7 mJ mL−1 after consuming the same amount of tap water compared with the droplet‐based electricity generators. After which, the excellent power output lights 2 W LED and drives wearable electronic devices. This device also inhibits carbon steel materials' corrosion in solutions through the evaporation effect of the salt water on the spot. The present study provides novel insights for triboelectric nanogenerators regarding energy sources and promotes the practical application of evaporation‐power generation technology. [ABSTRACT FROM AUTHOR]

This study used environmentally friendly nano-xylan to enhance the drug loading and preservative performance (especially against white-rot fungi) of pine wood (Pinus massoniana Lamb), determine the best pretreatment, nano-xylan modification process, and analyze the antibacterial mechanism of nano-xylan. High-temperature, high-pressure steam pretreatment-assisted vacuum impregnation was applied to enhance the nano-xylan loading. The nano-xylan loading generally increased upon increasing the steam pressure and temperature, heat-treatment time, vacuum degree, and vacuum time. The optimal loading of 14.83% was achieved at a steam pressure and temperature of 0.8 MPa and 170 °C, heat treatment time of 50 min, vacuum degree of 0.08 MPa, and vacuum impregnation time of 50 min. Modification with nano-xylan prohibited the formation of hyphae clusters inside the wood cells. The degradation of integrity and mechanical performance were improved. Compared with the untreated sample, the mass loss rate of the sample treated with 10% nano-xylan decreased from 38 to 22%. The treatment with high-temperature, high-pressure steam significantly enhanced the crystallinity of wood. [ABSTRACT FROM AUTHOR]

In this paper, aligned graphene sheets (AGS) embedded in PDMS (AGS@PDMS) has been prepared by repeated spin-coating (SC) technique. The triboelectric nanogenerator (TENG) based on the AGS@PDMS film is fabricated and its electric output is investigated systematically with different contents of filling graphene sheets and different spin-coating layers. The PDMS embedded with AGS is compared with that of disordered graphene sheets and graphite particles with different sizes. The capacitance, dielectric loss, conductivity and resistance of the PDMS composite film are characterized and analyzed. The output current of the TENG based on AGS@PDMS film is 3 times as much as that of the TENG based on pure PDMS film and the output power density reaches 4.8 W/m 2 at the load resistance of 15 MΩ. In addition, the TENG can be used as a pressure sensor to measure the mass and height of an object. This work demonstrates that the voltage applied on whole TENG is distributed to micro capacitors formed by aligned graphene sheets in PDMS, by which the higher breakdown voltage and energy conversion ability are achieved. [ABSTRACT FROM AUTHOR]

A hierarchical CuO nano-structure is prepared by directly growing CuO nanoflowers on carbon fiber fabric (CuO/CFF) via a hydrothermal method. The CuO/CFF is used as the electrode material of a supercapacitor for electrochemical energy storage. The supercapacitor displays superior electrochemical performance in aqueous electrolyte with the specific capacitance of 839.9 F/g at the scan rate of 1 mV/s, energy density of 10.05 Wh/kg and power density of 1798.5 W/kg, which are the highest values for the CuO/CFF electrodes. Moreover, a flexible symmetric solid-state symmetric supercapacitor is also fabricated by using the CuO/CFF as electrodes. The solid-state supercapacitor exhibits a specific capacitance of 131.34 F/g at the scan rate of 1 mV/s with a power density of 145.12 W/kg, and 95.8% capacitance retention after 2000 charge-discharge cycles. [ABSTRACT FROM AUTHOR]

Triboelectric nanogenerators (TENGs) to harvest ocean wave blue energy is flourishing, yet the research horizon has been limited to centimeter‐level TENG. Here, for the first time, a TENG shell is advanced for ocean energy harvesting to 0.5 m and an excellent frictional areal density of 1.03 cm−1 and economies of scale are obtained. The unique structure of the multi‐arch shape is adopted to untie the difficulty of fully getting the extensive friction layer contact. An inside steel plate is vertically placed in the center of every TENG block, which can activate the TENG to achieve complete contact even at a tilt angle of 7 degrees. The proposed half‐meter TENG (HM‐TENG) has a broad response band from 0.1 to 2 Hz, a total transferred charge quantity up to 67.2 µC, and one single TENG can deliver an open‐circuit voltage of 368 V. Coupled with the self‐stabilizing and susceptible features the ellipsoid shell brings, the HM‐TENG can readily accommodate itself to the all‐weather, all‐sea wave energy harvesting. Muchmore, the HM‐TENG is also applied to RF signal transmitters. This work takes the first step toward near‐meter‐scale enclosures and provides a new direction for large‐scale wave energy harvesting. [ABSTRACT FROM AUTHOR]

Highlights: The novel elliptical cylindrical structure (EC) provided an excellent self-stability, high sensitivity in small agitations, and most importantly, a distinctive anti-overturning capability for the EC-triboelectric nanogenerator (EC-TENG). Benefitting from the fully symmetrical design, the EC-TENG could maintain the original output after being overturned under extreme conditions, distinguishing itself from previous TENGs. Two built-in TENGs designed for use in rough seas and tranquil seas improved the collection efficiency for all-weather wave energy.Triboelectric nanogenerators (TENGs) have shown promising potential for large-scale blue energy harvesting. However, the lack of reasonable designs has largely hindered TENG from harvesting energy from both rough and tranquil seas. Herein, a fully symmetrical triboelectric nanogenerator based on an elliptical cylindrical structure (EC-TENG) is proposed for all-weather blue energy harvesting. The novel elliptical cylindrical shell provides a unique self-stability, high sensitivity to wave triggering, and most importantly, an anti-overturning capability for the EC-TENG. Moreover, benefiting from its internal symmetrical design, the EC-TENG can produce energy normally, even if it was overturned under a rude oscillation in the rough seas, which distinguishes this work from previous reported TENGs. The working mechanism and output performance are systematically studied. The as-fabricated EC-TENG is capable of lighting 400 light-emitting diodes and driving small electronics. More than that, an automatic monitoring system powered by the EC-TENG can also monitor the water level in real-time and provide an alarm if necessary. This work presents an innovative and reliable approach toward all-weather wave energy harvesting in actual marine environments. [ABSTRACT FROM AUTHOR]

Nickel-titanium (NiTi) alloys are key in making medical implants due to their mechanical properties and biocompatibility, yet suffer from microbiologically influenced corrosion (MIC). This study isolated three samples of intestinal microbiotas from patient's stents to investigate their corrosion behavior on NiTi alloy. Using metagenomic analysis, corrosion electrochemistry, and morphology characterization, we found that different microbiota samples formed biofilms on NiTi alloy, causing varying degrees of pitting corrosion. The corrosion was linked to riboflavin-mediated MIC, with differences in riboflavin synthesis genes affecting corrosion rates. This research offers new insights into the MIC of NiTi alloys and helps develop more corrosion resistant materials. • Human intestinal microbiota significantly accelerates MIC of NiTi alloy. • Different human intestinal microbiota samples lead to distinct patterns of pitting corrosion and varying corrosion rates. • Riboflavin is identified as a facilitator of MIC by intestinal microbiota. [ABSTRACT FROM AUTHOR]

The comprehension of the dynamic behavior and energy flow characteristics of triboelectric nanogenerators on water is a prerequisite for enhancing wave energy conversion efficiency and output performance, yet these data have always been lacking, impeding their progress in harnessing blue energy. Herein, a series of meticulously conducted experiments aim to unveil the interaction between water waves and the geometrical structures of floating triboelectric nanogenerators (F-TENGs). The six degrees of freedom (6DoF) information of various F-TENGs under wave excitation is received for the first time by employing the new high-tech Infrared Optical Capture System and precision numeric analysis. Based on statistical data from 118 research papers, the most universally applicable modes/parameters are systematically explored, as well as the non-rigid body models. The six-dimensional kinematic radar matrices and energy gradient curves, peeled from the calculation and statistics of the 6DoF data, have comprehensively illuminated the dynamic behavior and energy flow of F-TENGs while interacting with water waves. These results can serve as an enlightening framework for structural design and facilitate the optimization of F-TENG in harnessing blue energy. Using the infrared optical motion capture system to monitor the six-degree-of-freedom motion of triboelectric nanogenerators under wave excitation, with the aim of kinetics analysis and mechanical energy calculations, thus facilitating the prediction of optimized structural designs. [Display omitted] • A novel method is introduced for the six-degree-of-freedom analysis of floating triboelectric nanogenerators (F-TENGs). • The non-rigid models with control variables are universal and close to the real situation. • F-TENGs' comprehensive attitude tracking and analysis of dynamics/energy under wave excitation are provided. • The resulting rules can facilitate and guide the structural optimization of F-TENGs for wave-energy conversion. • Fluid dynamics analysis software is employed to elucidate the rules governing F-TENG parameters. [ABSTRACT FROM AUTHOR]

The typical climatic and environmental conditions in Central Asia are major natural factors causing local rock masses to face considerable risks of damage due to constant freeze-thaw cycles. In addition, these are exacerbated by the dense acidic environments in certain industrialized areas, such as Northern Sinkiang, China. To provide local engineering design with workable solutions, it is crucial to analyze the mechanical performance of rock masses and its mechanisms under the coupling action of corrosive acid and freeze-thaw cycles. In this study, granite samples from the northern Tien Shan Mountains near Urumchi, Xinjiang Province, as well as two kinds of sandstone samples for comparison, were subjected to different soaking conditions, including nitric acid soaking at various pH values. One or both of the freeze-thaw cycle tests and uniaxial compression test were then executed. Speculations regarding the mechanism of the performance of granite rock masses under the action of corrosive acid and freeze-thaw cycles were developed based on the results of these tests. X-ray diffraction and scanning electron microscopy were implemented to demonstrate the feasibility of the speculated mechanism. In this paper, the identification of the white crumb-like substance as SiO2 gel were confirmed. [ABSTRACT FROM AUTHOR]

Highlights: By counting the positive/negative pulses in unit time to sense the degree, speed, and direction of finger motion in real-time. The magnetic array assisted sliding structure translates sliding motion into contact-separation thus improves the durability and low-speed signal amplitude. The magnetic track constrains the sliding direction that greatly improves the stability.In human-machine interaction, robotic hands are useful in many scenarios. To operate robotic hands via gestures instead of handles will greatly improve the convenience and intuition of human-machine interaction. Here, we present a magnetic array assisted sliding triboelectric sensor for achieving a real-time gesture interaction between a human hand and robotic hand. With a finger’s traction movement of flexion or extension, the sensor can induce positive/negative pulse signals. Through counting the pulses in unit time, the degree, speed, and direction of finger motion can be judged in real-time. The magnetic array plays an important role in generating the quantifiable pulses. The designed two parts of magnetic array can transform sliding motion into contact-separation and constrain the sliding pathway, respectively, thus improve the durability, low speed signal amplitude, and stability of the system. This direct quantization approach and optimization of wearable gesture sensor provide a new strategy for achieving a natural, intuitive, and real-time human-robotic interaction. [ABSTRACT FROM AUTHOR]

• Model integrated DOC-DPF system assisted by electric regeneration. • Low, medium and high temperature performance study under two actual cycles. • New method for studying thermal response performance. • Impact trend comparison of filter structure parameters on DPF performance. A model is established to investigate low temperature (<300 °C), medium temperature (300–550 °C) and high temperature (>550 °C) performance of the continuous regenerative diesel particulate filter (CR-DPF) assisted by electric regeneration regarding to balance point temperature, regeneration speed and outlet temperature respectively and relevant influencing factors. Results show that inlet PM concentration and inlet flow rate are positively correlated to balance point temperature and vice versa for initial soot loading and intake NO X concentration. Increasing intake NO X concentration and flow rate increase rapid continuous regeneration speed. At low and medium temperatures, rapid thermal response tends to increase passive regeneration speed and the trend is more with decreasing wall thickness and channel density. In the high temperature range, outlet temperature increases and temperature gradients presented in the early stage of regeneration become steeper with decreasing channel density and wall thickness. However, "L/D" has limited impact on low, medium and high temperature performance. [ABSTRACT FROM AUTHOR]

• Tortuosity-porosity correlations are analyzed by least square method. • Sinuousoidal capillary bundle model is considered for washcoat diffusion. • Impact analysis of catalyst structural parameters on standard SCR reaction. • New insights into regime transition of standard SCR reaction. A model describing NH 3 selective catalytic reduction (NH 3 -SCR) over Cu-ZSM-5 to investigate the effects of intraphase and interphase mass transfer on standard SCR reaction is developed and further verified with the synthetic gas bench. The correlation between tortuosity and porosity has been analyzed by least squares method and applied to the sinuousoidal capillary bundle model. The effects of washcoat thicknesses, lengths, cell densities and channel widths on the standard SCR reaction are analyzed in temperature range of 150–500 °C. It is found that deNOx efficiency is affected by intraphase diffusion limitations at 200–500 °C and by interphase mass transfer limitation at intermediate (250–400 °C) and high temperatures (400–500 °C). As the temperature increases, the reaction is firstly controlled by kinetics, with the kinetics resistance decreasing and then increasing until the maximum among three processes. Furthermore, intake flow rates (GHSVs) play an important role impacting NO conversion on NH 3 –SCR. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Kinetic equation is established to predict the supercritical water gasification. • Operating range of temperatures of 550–850 °C and residence times of 1–15 min are obtained. • A series of kinetic models are chosen to simulate the experimental results. • A semiempirical MRP model is used to describe the kinetic behavior of the SCWG, and correlation coefficient exceeds 0.995. Abstract The gasification kinetic characteristics of food waste (FW) gasification by supercritical water (SCW) were investigated by examining the SCW gasification (SCWG) of FW in a quartz tube reactor, and the experimental results were investigated by using a series of kinetic models. The experimental results show that the carbon gasification efficiency increases with reaction temperature at the same residence time, and reactivity increases sharply at the early stage of gasification and then decreases with reaction time. The simulation results show that all the classical kinetic models underestimate the experimental results, similar to the models used in previous work on coal gasification by SCW. The underestimation of the models results from the catalytic effect of alkaline earth metals (AAEMs), which can notably increase the active sites of gasification reaction without changing the gasification kinetic mechanism. To solve the above problem, the catalytical effect to describe the kinetic behavior of the SCWG of FW is considered and a semiempirical modified random pore model (MRPM) is developed based on the RPM model. The simulation results of the MRP models are close to experimental findings, indicating that MRP model can be used to predict the entire process of SCWG under different conditions without dividing gasification into different stages of reaction. The MRP model can also be used for the prediction of SCWG of coal, biomass, and organic wastes and is crucial to reactor optimization and scaling up. [ABSTRACT FROM AUTHOR]

We have synthesized a ceramic sample 0.85Pb(Sc0.5Ta0.5)O 3 -0.15PbTiO 3 [0.85PST-0.15PT] of perovskite structure by using a conventional solid-state reaction method. Systematic impact of annealing time (AT) is studied methodically for comprehending the ferroelectric and dielectric properties, as well as electrocaloric effect and energy harvesting performance. After 40 h of AT and using the electric field of 40 kV/cm on 0.85PST-0.15PT, we have achieved maximum ferroelectric polarization (P = 46.9 μC/cm2), energy capture performance (W = 0.542 J/cm3), and large positive electrocaloric effect (ΔT ∼ 1.63 K and ΔS ∼ 1.23 J/(K.kg)). Additionally, we also achieved high dielectric constant (ε = 23,350) and low dielectric loss (tanδ = 0.039) at the frequency of 1 Hz. As compared to an unannealed situation, the results on ceramic sample with 40 h of AT have revealed increase in P, ε, ΔT, ΔS, and W by 36%, 27%, 37%, 12% and 14%, respectively. Optimal values of AT differed radically for achieving the highest performance in each category. The best performance of energy storage (W energy ∼ 0.638 J/cm3) and energy loss (W loss ∼ 0.498 J/cm3) densities are achieved with the AT of 30 h. The performance of 0.85PST-0.15PT sample increased gradually with the increase of AT until it attained the highest value and then decreased by further increasing AT – exhibiting a peak distribution. Our investigations have provided valuable insights of optimizing the performance of 0.85PST-0.15PT ceramic system through annealing. • 0.85PST-0.15PT ceramics with large electrocaloric effect near room temperature were successfully prepared. • Systematic impact of annealing time (AT) on 0.85PST-0.15PT ceramics is studied to comprehend the comprehensive performance. • After 40 h of annealing, the 0.85PST-0.15PT ceramics exhibited significant improvements in various performance aspects. • Investigations provide valuable insights into optimizing the performance of PST-PT ceramic systems through annealing. [ABSTRACT FROM AUTHOR]

Swelling soft rocks will exhibit strong dilation and softening due to water immersion ofwhich it is, generally, a time-dependent deformation in relation with humidity distribution. Itis hard to describe this kind of creep property by means of the existing rheological model.Therefore, in this paper, A new model is presented by a modified generalized Kelvinelement in series with a plastic cell introduced on the assumption that the materialcorresponds to Mohr-Coulomb criterion as well as corresponding plastic flow rule afteryielding. The generalized Kelvin model (Three Parameters Solid Model) is modified byintroducing the swelling coefficient α depending on rocks attribute and viscosityattenuation coefficient ξ to consider the humidity factor based on the humidity field theory.According to the theory, there are three main processes as the swelling rock subjected towetting which like that of the thermal behavior of materials: the humidity transport withinswelling rocks triggers the change of humidity field; the change of humidity field lead to thedilation and softening, then by which the change of stress and displacement fields areexhibited. The new model can simulate the viscoelastic-plastic deviation characteristics and theelastic-plastic volume behavior under different humidity condition. The correspondingviscoelastic-plastic constitutive relation is deduced, and the solution method of modelparameters is given. The rheological model is redeveloped by FLAC 3D to simulate the creepcharacteristic of swelling soft rock in humidity field and the creep parameters under differentwater content were fitted by the experimental data. The results demonstrate that theexperimental curves are in good agreement with the theoretical curves based on the newmodel. The modified generalized Kelvin creep model can not only reflect the two kinds ofcreep characteristic of swelling soft rock under humidity field-the deformation isrelatively faster at first and gradually tends to be stable after a period of time atlow stress loading while it gradually transforms into unstable creep at high stressloading-but also the different creep curves of swelling soft rock under different watercontent. Key words: generalized Kelvin model; humidity field theory; Mohr-Coulomb;viscoelastic-plastic; swelling soft rock [ABSTRACT FROM AUTHOR]

This paper presents an investigation into the coupled effects of chemical corrosion(by Nitric acid solution) and freeze-thaw cycles on the physical and mechanicalproperties and damage deterioration of tanolite specimens. The experiments included theuniaxial compression test, the Young&#x2019;s modulus test, the X-ray diffraction test and thescanning electron microscope test. The damage condition of tanolite specimens wasanalysed using scanning electron microscope (SEM). The experimental resultsreveal that chemical erosion has a significant influence on the propagation of microcracks and accelerates the development of damage in the tanolite samples undermonotonic loading. Due to cementation, no obvious difference in uniaxial compressivestrength was observed between the specimens subjected to combined effects ofchemical corrosion and freeze-thaw cycles and those subjected to freeze-thaw cyclesonly. The amount of cementing materials in the chemically treated specimens wasfound using SEM. The results of XRD and SEM can prove that the SiO2 particlesare absorbed into cracks and voids. Meanwhile, based on the result of Young&#x2019;smodulus, the chemical corrosion makes further damage to specimens with freeze-thawcycles can be proved. As more cracks and pores are generated in the specimensdue to freeze-thaw cycles, SiO2 colloidal particles can move into specimens withthe acid solution. In addition, the result of peak strain shows that SiO2 colloidalparticles can increase the peak strain of tanolite specimens subjected to freeze-thawcycles. Key words: Tanolite; chemical corrosion; freeze-thaw; combined effect; mechanicalproperties [ABSTRACT FROM AUTHOR]

It is known that Faradaic redox reactions take place on the surface or inside of materials through ion insertion/extraction on the surface. Therefore, rational design of nanostructures to enlarge the specific surface of electrode materials is an effective way to achieve desirable electrochemical performance. In this paper, three kinds of copper oxide structures, including flower-like, particle-like and coral-like arrays grown on the carbon fiber fabrics, are prepared by the hydrothermal method under different conditions. These flowers, particles and corals are further assembled by nanoscale sheets, rods and porous networks, respectively. The flexible solid-state symmetric supercapacitor based on two electrodes of these CuO nanostructures is fabricated, and the electrochemical properties of these CuO nanostructures are investigated, from which we find that the supercapacitor based on the coral-like CuO nanostructure presents better performance than that of particle-like and flower-like CuO due to its higher specific area and suitable pores with rich reaction sites and ion diffusion channels. The specific capacitances of the flower-like, particle-like and coral-like CuO are 164.50, 309.65 and 481.76 F g, respectively, at scan rate of 5 mV s. The specific capacitance of the coral-like nanostructure keeps 86.45% after 2000 cycles. These results indicate that the morphology influences the electrochemical properties greatly. Three supercapactiors connected in series can light up ten LEDs for 600 s. [ABSTRACT FROM AUTHOR]

In order to improve the performance of the piezoelectric actuator and considering the uncertain factors in the working process of the piezoelectric actuator, a novel H ∞ robust controller is developed. Firstly, the hysteresis characteristic of the piezoelectric actuator is studied and the fuzzy least square support vector machine is adopted to solve the hysteresis problem, then the model is established; secondly, the method of H ∞ robust theory is introduced to control the piezoelectric actuator and in the process of the design, the chaos optimization algorithm is applied to optimize the weight function of the H ∞ robust controller, then the final controller is established; at last, the simulation model of the optimized H ∞ robust control system and the not optimized system are built, also the intelligent PID control system is built to compare the control effect. Results show that the optimized H ∞ robust control system is robust with high stability, which can eliminate the disturbance from the outside and has been proved to be an excellent controller. [ABSTRACT FROM AUTHOR]

In the study of rock mechanics, the variation of rock mechanical characteristics in high-temperature environments is always a major issue. The discrete element method and Voronoi modeling method were used to study the mechanical characteristics and crack evolution of granite specimens subjected to the high temperature and uniaxial compression test in order to study the internal crack evolution process of granite under the influence of high temperatures. Meanwhile, dependable findings were acquired when compared to experimental outcomes. A modified failure criterion was devised, and a Fish function was built to examine the evolution behavior of tensile and shear cracks during uniaxial compression, in order to better understand the evolution process of micro-cracks in granite specimens. Shear contacts occurred first, and the number of shear cracks reached its maximum value earliest, according to the findings. The number of tensile contacts then rapidly grew, whereas the number of shear cracks steadily declined. Furthermore, it was found that when temperature rises, the number of early tensile cracks grows. This study develops a fracture prediction system for rock engineering in high-temperature conditions. [ABSTRACT FROM AUTHOR]

• A washcoat resolved model of catalytic micro reactor fueled by methane is developed. • Effective mass diffusion is implemented in porous washcoat domain. • The micro reactor works in internal diffusion and reaction mixed-controlled regime. • Parametric studies are done regarding to porous washcoat properties. A washcoat resolved numerical model of catalytic micro combustor fueled by methane is developed. Detailed gas phase mechanism and alumina dioxide supported Pt-based surface mechanism are adopted. This model proves to capture flow, temperature and species fields precisely including impermeable flow and products accumulation in porous washcoat layer. The novelty and superiority of this research compared to traditional modeling method in which instantaneous diffusion onto catalytic wall is assumed lies in that: it is possible to investigate effects of porous washcoat properties with this full-scale numerical model. Computational results show that homogeneous reactions (HR) are impaired and heterogeneous reactions (HTR) are strengthened as channel confinement increases. Da number analysis reveals that the micro combustor works under a mixed controlled mode in which catalytic reaction rate and internal mass diffusion rate are comparable. When washcoat layer thickness increases from 15 μm to 75 μm, overall catalyst usage roughly decreases from 0.34 to 0.05. It is concluded washcoat thickness can't be too thin in order to maintain HTR intensity and too thick since catalyst usage is extremely low. Porous washcoat properties impact combustion characteristics in a similar mechanism: modifying effective mass diffusion coefficient. In general, increasing porosity, average pore diameter and decreasing tortuosity will enhance HTR and impair HR. In real application, these parameters can be utilized to modify combustion temperature, emission performance and stability operation map. [ABSTRACT FROM AUTHOR]

Carbon materials are the most important anode materials used in supercapacitors. However, there are still great challenges in improving their low specific capacitance and energy density. In this study, a fast molten salt method was developed for the preparation of a super-high capacity activated carbon cloth anode. The nitrogen-activated carbon cloth electrode (NCC) showed better electrochemical performance than most of the carbon-based materials reported on previously. The maximum areal capacitance of the nitrogen-activated carbon cloth electrode was 6.72 F cm−2 at the current density of 2 mA cm−2. By employing the first-principle calculations method, it was derived that the adsorption energy of the K atoms on the graphite increased with the increase in nitrogen doping, especially on the pyridinic nitrogen (N-6). In addition, when the NCC and Ni-Co-S@CC electrodes were assembled into an asymmetric supercapacitor (ASC), the ASC demonstrated an operation in a large potential window of 1.8 V, and it achieved a high volumetric energy density of 23.51 mWh cm−3 at a power density of 1808 mW cm−3. This work showed the super high capacity of activated carbon cloth as a new anode material for high-performance supercapacitors prepared using a simple molten salt method. In this work, we provide a fast molten salt method for preparing super-high capacity of activated carbon cloth (NCC) as anode. The experimental results show that it has especially higher electrochemical performance than most of the carbon-based materials reported previously. When NCC anode and Ni-Co-S@CC cathode are assembled into asymmetric supercapacitor, it shows high volumetric energy density and power density. Image 1 • Nitrogen-activated carbon cloth is prepared by a fast molten salt method for the first time. • The calculation indicates that adsorption strength of K ions is enhanced by nitrogen doping. • The assembled asymmetric supercapacitor delivers ultrahigh volumetric energy density of 23.51 mWh cm−3. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) materials have been attracting research interest due to their specific properties including supper large surface area, more active sites and fast electron transmission, which are beneficial to the improvement of energy and power densities for supercapacitors (SCs). In this paper, 2D LiCoO 2 (2D-LCO) is prepared by fine-tuning the time in the synthesis process through a fast-composite-hydroxide-mediated approach. The electrode with the 2D-LCO mass load of 0.75 mg/cm2 exhibits the high specific capacitance of 310 mF/cm2 at 5 mV/s. Moreover, the asymmetric supercapacitor assembled by 2D-LCO//Fe 2 O 3 /FeOOH delivers a high areal energy density of 56.25 μWh/cm2 at 1100 μW/cm2 with working window of 2.2 V and an excellent cycling stability of 80% at current density of 10 mA/cm2 for 2000 cycles. • 2D-LiCoO 2 is synthesized by a fast composite-hydroxide-mediated approach, which is convenient, low-cost, and nontoxic. • Asymmetric supercapacitor (ASC) is assembled by 2D-LiCoO 2 and Fe 2 O 3 /FeOOH as positive and negative electrode respectively. • The ASC displays a high areal specific energy and power of 56.25 μWh/cm2 at 1100 μW/cm2 with a wide working window of 2.2 V. [ABSTRACT FROM AUTHOR]

Triboelectric nanogenerators with a large number of desirable advantages, such as flexibility, light weight, and easy integration, are unique for sensor design. In this paper, based on the triboelectric nanogenerator (TENG), a cylindrical self‐powered multifunctional sensor (MS) with a translational‐rotary magnetic mechanism is proposed, which has the capacity to detect acceleration, force, and rotational parameters. The MS can transform a translational motion into a swing motion or a multicircle rotational motion of a low damping magnetic cylinder around a friction layer and hence drives the TENG to generate voltages output. For enhancing the output performance of the TENG, an electrode material with small work function, low resistance, and suitable surface topography is the best choice. According to the structure characteristic of the translational‐rotary magnetic mechanism, the MS can easily respond to a weak striking and can be used to measure the rotational parameters without the need of coaxial installation. Based on the MS, some applications are established, for example measuring the punch acceleration of a boxer, the hitting force and swing angle of golf club, which demonstrate the feasibility and efficiency of the MS and exhibit that the MS could find applications in sports. [ABSTRACT FROM AUTHOR]

Accurately monitoring human gait is critical for health evaluation and/or early diagnosis, especially for elder and injured people's healthcare. The presence of gait abnormalities could be important predictors of the risk of developing diseases. Herein, a triboelectric nanogenerator (TENG)‐based smart insole for real‐time gait monitoring is reported. Due to the novel air‐pressure‐driven structural design, the elastic TENG‐based sensors exhibit compelling features including simple fabrication, fast response time, high durability, and excellent mechanical robustness. The TENG‐based sensors can be easily integrated into the conventional insole so that it can convert the mechanical triggering/impact into electrical output. By analyzing such electrical signals, the smart insole could accurately monitor and distinguish various gait patterns in real time, including jump, step, walk, and run. The smart insole could also be used to monitor the abnormality of gait for rehabilitation assessment. In addition, the smart insole can play another important role in healthcare applications, for example, serving as a fall‐down alert system for elder people or patients. This work not only paves a new way for real‐time and long‐term gait monitoring, but also presents a new perspective for the practical applications of remote clinical biomotion analysis. A triboelectric nanogenerator (TENG)‐based smart insole for real‐time gait monitoring is reported. The TENG‐based sensors can be integrated into the conventional insole so that it can convert the mechanical triggering/impact into electrical output. This work not only paves a new way for real‐time gait monitoring, but also presents a new perspective for the practical applications of remote clinical bio‐motion analysis. [ABSTRACT FROM AUTHOR]