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Contact electrification (CE) has been utilized in various energy conversion systems in recent years. This work presents a constant electric energy output that was generated based on the CE at the water–metal interface. When a grounded Pt mesh is placed in water that is heated to boil, a continuous flow of electrons between the Pt mesh and the ground is generated. A possible mechanism for the generation of such electric current is based on the CE between the surface of the Pt mesh and water molecules. The local high-pressure thin liquid film regions between vapor bubbles and surface of Pt mesh promote this CE process. The constant water evaporation and bubble detachment enable the continuous electric current output. In this work, the impact of the heating temperature and the bias voltages on the generation of the current was also studied. This work provides an alternative approach to generate unidirectional current on the basis of CE at the water–metal interface, and it also offers new insights in the design of CE-based systems for the generation of electricity.

Nowadays, scanning induction thermography (SIT) could be efficient and practical for the inspection of elongated ferromagnetic specimens in the manufacturing process. Owing to the relative movement between the specimen and excitation coil, defect visualization and depth quantification in SIT remain challenging. Focusing on these two challenges, surface-breaking notches with different depths in a steel plate at different scanning speeds have been studied in this paper. A visualization method, including image reconstruction and Wiener filter, is proposed to realize defect visualization within 600 mm/s. Then, thermal features are extracted to realize depth quantification for notches within 3.0 mm. In addition, the effect of scanning speed on the SIT detectability is investigated and it is found that the signal-to-noise ratio (SNR) decreases significantly with increasing scanning speed.

An atomically dispersed structure is attractive for electrochemically converting carbon dioxide (CO2) to fuels and feedstock due to its unique properties and activity. Most single-atom electrocatalysts are reported to reduce CO2 to carbon monoxide (CO). Herein, we develop atomically dispersed indium (In) on a nitrogen-doped carbon skeleton (In-N-C) as an efficient catalyst to produce formic acid/formate in aqueous media, reaching a turnover frequency as high as 26771 h-1 at -0.99 V relative to a reversible hydrogen electrode (RHE). Electrochemical measurements show that trace amounts of In loaded on the carbon matrix significantly improve the electrocatalytic behavior for the CO2 reduction reaction, outperforming conventional metallic In catalysts. Further experiments and density functional theory (DFT) calculations reveal that the formation of intermediate *OCHO on isolated In sites plays a pivotal role in the efficiency of the CO2-to-formate process, which has a lower energy barrier than that on metallic In.

The advancement of power-type lithium ion batteries (LIBs) mainly depends on the construction of electrodes with superior electronic & ionic conductivity. In this work, a synergistic combination of nitrogen doped Li4Ti5O12 (N-LTO) nanoparticles and highly conductive vertical graphene (VG) skeleton is proposed to obtain ultrafast Li ion storage performance via a facile hydrothermal-nitridation method. The as-synthesized composite nanosheets are composed of interconnected N-LTO shell and VG core to form the final N-LTO/VG core-shell arrays, which are systematically studied as the anodes of LIBs. In virtue of the positive synergistic effect of high conductive VG backbone and nitrogen doping, overwhelming advantages including high specific surface area, superb structural stability and enhanced conductivity are achieved in the well-designed N-LTO/VG electrodes. Accordingly, the as-synthesized N-LTO/VG electrode shows outstanding high rate capacity (142.5 mAh g−1 at 20 C) and superior long-term cycling stability (capacity retention of 98.9% after 10000 cycles at 5 C), better than LTO/VG electrode without N doping. Our research provides a new strategy for the synthesis of high-performance hybrid electrodes for application in power-type LIBs.

Subsurface discontinuities are inevitably formed during the long-term operations of pipelines, oil tanks, ship hulls, and the like. However, it is still a big challenge to detect deeply buried subsurface discontinuities using existing nondestructive testing methods. In this paper, based on the high sensitivity of magnetic Barkhausen noise (MBN) to the movement of the domain walls, an MBN test under direct current (DC) magnetization is proposed for subsurface discontinuity detection. Under DC magnetization, subsurface discontinuities will distort the magnetic field distribution in the near-surface layer of the specimen and then affect the movement of the domain walls in this region. Meanwhile, through alternating current (AC) excitation, MBN testing is conducted to detect the movement of the domain walls to evaluate subsurface discontinuities. To validate the proposed technique, MBN experiments under DC magnetization are conducted to quantify subsurface discontinuities with different buried depths. Experimental results indicate that the proposed technique can detect subsurface discontinuities with buried depths of up to 5 mm, and the extracted MBN energy feature has an approximately linear relationship with the buried depth.

Summary Corrosion of nanoparticles during electrocatalysis, such as oxygen reduction reaction (ORR), occurs at the nanoscale and is vital for catalyst stability. Here, using liquid cell (LC) transmission electron microscopy (TEM), we study the corrosion process of palladium@platinum (Pd@Pt) core-shell octahedra in real time and reveal that both the static local strain and the evolving curvature synergistically control the nanoscale corrosion kinetics. Specifically, in locations with tensile strain and high local curvature, the etching process is much faster. Density functional theory (DFT) calculation suggests that the dissolution potential of the Pd nanocrystal decreases as the strain increases; meanwhile, Pd atoms tend to be corroded more easily on a surface under tensile strain than on one under compressive strain. With these insights on the corrosion mechanism at the nanoscale, we subsequently designed and synthesized nanoparticles with smaller strain, and these showed higher durability in both an in situ LC study and an ex situ ORR stability test.

Eddy current array testing (ECAT) is a useful tool in evaluating defect sizes. However, it is difficult for ECAT to evaluate the inner defects in ferromagnetic materials due to thin skin effect. In this article, direct current (dc) magnetization-based ECAT (DCMECAT) is proposed to quantify buried defects existing in the inner surface of steel plates. Relying on permeability disturbance in the defect vicinity, DCMECAT can build links between the testing signals and defect sizes. The results show that the performance of evaluating defect sizes is better under the saturated magnetization state. Further, three features, i.e., the signal width, the peak voltage, and the contour orientation, are proposed to evaluate the width, the depth, and the orientation of defects, respectively. Relationships between features and defect sizes are investigated by using least-squares regression. Further, a testing example is shown in this article, and the evaluation error is 14%.

Well-designed nanostructures are very critical to the lithium-storage performance of electrode materials. To enhance the electrochemical performance of zinc oxide anode materials, a capsule structure, composed of carbon shell and its encapsulating ZnO microsphere, is designed. This capsule structured ZnO/C nanocomposite microspheres are prepared by a sol-gel method combined with two calcination processes. The carbon capsule shows great advantages of enhancing the structural stability of active material, reducing the formation of solid electrolyte interface (SEI) layer, and improving the conductivity of electrode. These factors are quite beneficial to the improvement of cycling stability, initial coulombic efficiency and rate capability. Consequently, capsule structured ZnO/C nanocomposite microspheres deliver an initial charge capacity of 790 mA h g−1, an initial coulombic efficiency of 71%, and a reversible capacity retention of 63% after 100 cycles, all of which are higher than those of pure ZnO microspheres. These results suggest that the design of carbon encapsulated ZnO microsphere is quite effective for enhancing the lithium-storage properties and can also show general significance for developing high-performance electrode materials.

Thermography is one of advanced non-destructive test and evaluation for imaging defects. This paper proposes pulsed air-flow thermography for sample surface crack detection and evaluation. The proposed approach combines the advantages of both convection heat transfer of air-flow and solid heat conduction. By controlling the pulse width, the heat waves of different frequencies can be modulated to penetrate materials with different thermal conductivity. And the cleaning degree of specimen surface can be improved by high-speed air-flow convection. The theoretical model and experimental facilities of air-flow thermography are presented. Meanwhile, the offline detection of rail surface defects and the dynamic test of the defects on the outer cylindrical surface of the turn-plate are completed. The offline experiments are conducted to identify the characteristics of the proposed method for the detection of artificial and natural cracks. And the dynamic experimental results show that the defects on the outer cylindrical surface of the turn-plate can be identified when the linear velocity at the edge of the turn-plate is 1.356km/h and 6.782km/h. The results demonstrate the proposed method on testing and evaluation for rail surface cracks is effective at the low speed.

In this paper, experimental method and first-principles calculations were combined to study the properties of pure hydroxyapatite and Zn-doped hydroxyapatite. Pure and Zn-doped hydroxyapatite (HA) powders were synthesized using the hydrothermal method. The FTIR spectra show that the adding of Zn atoms makes the intensity of PO43− stretching peaks become weaken and obscure. In addition, the O-H bending peaks at 3570 and 632 cm−1 become weaker and broader. The XRD patterns show that the replacement of Zn ion in the HA structure leads to the distortion in HA lattice, which is shown and proved by the TEM analysis. First-principles calculations based on density functional theory (DFT) method were applied to investigate the Zn-doped hydroxyapatite. The elastic properties of HA, HA with Ca2+(II) vacancy, and Zn doped HA systems were calculated. Through the calculation, we found that the doping of Zn atoms made the elastic modulus of HA crystal becoming soft. The elastic properties dropped dramatically when there is a vacancy in the Ca2+(II) position. Compared with the HA-VCa2+ structure, the Zn-doped HA has better elastic properties and stability. The local structure of the substitution position was presented and analyzed. In the Zn-doped HA structure, the OH− group adjacent to Zn2+ is significantly displaced from the c axis toward to the Zn2+, making the lattice distorted. The distortion of the crystal lattice is responsible for the weakness of the P-O stretching peaks and O-H bending peaks in the FTIR spectra of the Zn doped HA crystal. The softness of the elastic modulus is also caused by the distortion of the lattice and the weak bonding force between Zn atom and O atom.

The urgent need of catalysts with improved performances toward the hydrogen evolution reaction (HER) is still one of the crucial issues for the water splitting electrocatalysis. Herein, we exhibit ...

Earth hummocks are widely distributed in arctic, sub-Arctic and alpine regions and have important roles in determining plant diversity and the nutrient content of soils. We investigated the impact of the spatial heterogeneity on soil properties and plant communities caused by the hummocks on the Tibetan Plateau. The results indicated alpine hummocks created higher plant diversity and soil fertile island patterns under Kobresia Genus communities. Vegetation height, cover, above-ground and underground biomass, species richness and diversity at the top of well-developed hummocks were the significantly higher than those in the inter-hummocks and surrounding flat ground. The soil organic carbon content in surface soil layer (0-50 cm) at the hummock top was 154.6% and 172.3% higher than those in inter-hummock area and the flat ground, respectively. From the developing to well-developed stage, K. littledalei became the dominant population at hummock top instead of K. humilis, and fertile islands gradually formed with higher soil organic carbon and total nitrogen, lower soil moisture and wider soil temperature variation. RDA analysis further indicated the interactions of plant community succession and soil fertile island could create positive feedbacks to nutrient-rich patches.

Controllable fabrication of advanced electrode materials is critical for the development of lithium ion batteries (LIBs). Herein, for the first time, we report novel hierarchical porous chromium niobium oxide (Cr0.5Nb24.5O62) microspheres prepared by a facile one-step solvothermal method. The as-prepared Cr0.5Nb24.5O62 microspheres present 3D hierarchical porous structure consisting of cross-linked nanoparticles, high electronic conductivity and large specific surface area. Accordingly, the Cr0.5Nb24.5O62 microspheres show noticeable lithium ion storage performance with superior high-rate capability (199 mAh g−1 at 20C) and good cycling stability with a capacity retention of 95% over 1000 cycles, much better than the bulk Cr0.5Nb24.5O62 and TiNb24O62 counterparts. Our work demonstrates a new high-rate electrode material for high-power energy storage.

In our previous study, we found that the methanolic extract of Sanoshashinto () (SHXXTM) exhibited significant vasorelaxant effects in vitro and antihypertensive effects in vivo, and baicalin and berberine were the main antihypertensive constituents in SHXXTM. We also speculated that the baicalin-berberine (BB) combination produced vasorelaxant effects by activating the NO/cGMP pathway, and the BKCa channel and the DAG/PKC/CPI-17 pathway were involved. In this study, we examined the vasorelaxant effects using helical strips of rat aorta pretreated with different activators or inhibitors. The results suggested that the KATP channel and the voltage-dependent Ca2+ channel (VDCC) were also involved in the vasorelaxant effects. Furthermore, we found that SHXXTM and the BB combination reduced left ventricular hypertrophy and altered gut microbiota. Together, the results indicated that Sanoshashinto might have comprehensive effects on ameliorating hypertension.

The relatively low energy density and poor cycling durability of aqueous rechargeable Co–Zn batteries are two main bottlenecks impeding their application in next-generation energy storage devices. A traditional solution for this issue is preparing complicated three-dimensional (3D) electrodes on conductive substrates by epitaxial growth, whose active material easily falls off. Herein, an aqueous rechargeable Co–Zn battery with ultrahigh energy density and excellent electrochemical reversibility is constructed by employing an ultrasonic-assisted growth of a Co(OH)2 nanosheet on Co foam (denoted as COHF) as the cathode. Taking advantage of in-situ formed electrochemically active Co(OH)2 and a porous 3D conductive framework, the COHF electrode presents an ultrahigh capacity of 0.265 mA h cm–2, 24-fold higher than that of pristine Co foam. Impressively, a remarkable energy density of 6.09 mW h cm–3 and a peak power density of 1.75 W cm–3 are achieved by the as-fabricated COHF//Zn battery. Moreover, this COHF/...

Owing to its high catalyzing nature, Pt holds great promise as an efficient catalyst for the oxygen reduction reaction (ORR). Although surface steps/kinks have been proven beneficial for the catalytic performance, constructing steps/kinks on Pt surfaces remains a big challenge due to the high surface energy. Herein, we demonstrate that the lattice mismatch can induce the growth of Pt shells with high-density steps on substrates. We exemplify it by depositing Pt shells on Pd–Cu alloy nanocubes, between which the lattice mismatch reaches 4.53%, and testing the resulting catalysts for the ORR. We show that Pt shells on Pd–Cu alloy nanocubes exhibit an extraordinary increase in both specific and mass activities of 32 and 16 times, respectively, as compared to the commercial Pt/C catalyst. Meanwhile, functional tests in proton exchange membrane fuel cells exhibit a 121.9 mW cm−2 increase in power density for Pd–Cu@Pt compared to the commercial Pt/C catalyst. Our result indicates that lattice mismatch between Pt shells and Pd–Cu alloy cores plays a key role in forming surface steps, while Pt shells grown on Pd cores only cause the formation of Pd@Pt nanocubes without surface steps. This work suggests that lattice mismatch can serve as an efficient parameter for preparing ORR catalysts with excellent activity and durability.

Context Hydroxysafflor yellow A (HSYA) has been shown to have neuroprotective effects in cerebral infarction. However, its underlying roles in apoptosis and inflammation in Parkinson’s disease (PD) are unknown. Objective The present study investigates the effects and underlying mechanisms of HSYA on dopaminergic (DA) neurodegeneration, inflammation, and apoptosis. Materials and methods The PD model was established by 2 μL of 6-hyroxydopamine (6-OHDA) (3 μg/μL) striatal injection in C57BL/6J mice with different doses of HSYA (2, 4, or 8 mg/kg). In vitro, after being treated with HSYA for 1 h, SH-SY5Y cells were exposed to 6-OHDA for 24 h before analysis. Expression of tyrosine hydroxylase (TH) in substantia nigra (SN) and corpus striatum (STR) was evaluated by immunohistochemistry (IHC) and western blot. In addition, apoptosis-related and inflammatory proteins were examined by western blot. Results Administration of HSYA significantly reduced the Apomorphine (APO)-induced rotation, decreased from 122.5 ± 15.1 (6-OHDA group) to 47.2 ± 14.3 (8 mg/kg HSYA group). HSYA partially restored a deficit in the SN and STR of PD mice brains in TH. Furthermore, western blot analysis revealed that HSYA reduced inflammatory proteins, including iNOS, COX-2 and NF-κB and attenuated the elevation of DA neuronal apoptosis observed in PD. In vitro assays showed that HSYA reduced the levels of p-p38 and p-JNK and increased that of p-ERK in 6-OHDA-leisoned SH-SY5Y cells. Conclusions These findings indicate that HSYA protects against 6-OHDA induced DA neurodegeneration partly by regulating the MAPK inflammatory signalling pathway and apoptosis which highlight its therapeutic potential in the treatment of PD.

The quantitative non-destructive evaluation (QNDE) of complex defects remains as challenges. The transient thermal responses of 3D eddy current pulsed thermography (ECPT) contains rich information for the defect characteristics. In this paper, a modified skewness feature extracted from the transient thermal responses is proposed for the QNDE in 3D ECPT. Different stages of the transient responses and their skewness features are experimentally investigated for angular cracks. The skewness feature is mapped to 3D point cloud captured by a 3D ranger in order to show the 3D skewness feature distribution. The heating stage is modified and inverted before the calculation of the entire transient thermal response due to different behaviors of skewness features at different transient stages. Results show that the modified skewness removed the counteracting effect of the temperature distribution in the heating stage and cooling stage, which make the modified skewness feature has higher sensitivity and linearity for the evaluation of defect depths.

Two-dimensional molybdenum disulfide (MoS2 ) nanosheets attract great interest for applications in lithium-sulfur (Li-S) batteries, due to their unique physical and chemical properties, which originate from diverse chemical compositions and unique electronic structures. In recent years, many efforts have been devoted to employing MoS2 as a polysulfide immobilizer and catalyst, functional separator, and Li-metal protection for Li-S batteries through structural design and electronic modulation. A fundamental understanding of the interplay between structural features, electronic properties, and advanced electrochemical performance is crucial for providing valuable insights for the development of Li-S batteries. In this regard, recent advances in Li-S batteries with 2D MoS2 materials are summarized from the perspective of structural design and electronic modulation. Finally, future prospects and remaining challenges of MoS2 for Li-S batteries are highlighted.

Rational design of cost-effective high-performance electrocatalysts for oxygen evolution reaction (OER) is of great significance for electrochemical water splitting. Herein, we adopt a nitrogen doping method to fabricate self-supported N-doped CoO nanowire arrays (N–CoO) as active electrocatalysts via a facile hydrothermal combined doping method. The N–CoO nanowires are strongly composited with the carbon cloth substrate forming free-standing electrode with reinforced stability and high electronic conductivity. Owing to the increased accessible and electroactive areas, rich/short pathways for charge transfer and enhanced electronic conductivity, the N–CoO electrode exhibits excellent electrocatalytic performance for OER with a low overpotential (319 mV at 10 mA cm−2 and 410 mV at 100 mA cm−2) and a low Tafel slope of 74 mV dec−1 as well as superior long-term stability with no decay in 24 h continuous test in alkaline solution. Our reported design and optimization strategy provide a promising way to construct interesting well-aligned arrays for application in energy storage and conversion.

Along with the technology evolution for dense integration of high-power, high-frequency devices in electronics, the accompanying interfacial heat transfer problem leads to urgent demands for advanced thermal interface materials (TIMs) with both high through-plane thermal conductivity and good compressibility. Most metals have satisfactory thermal conductivity but relatively high compressive modulus, and soft silicones are typically thermal insulators (0.3 W m-1 K-1). Currently, it is a great challenge to develop a soft material with the thermal conductivity up to metal level for TIM application. This study solves this problem by constructing a graphene-based microstructure composed of mainly vertical graphene and a thin cap of horizontal graphene layers on both the top and bottom sides through a mechanical machining process to manipulate the stacked architecture of conventional graphene paper. The resultant graphene monolith has an ultrahigh through-plane thermal conductivity of 143 W m-1 K-1, exceeding that of many metals, and a low compressive modulus of 0.87 MPa, comparable to that of silicones. In the actual TIM performance measurement, the system cooling efficiency with our graphene monolith as TIM is 3 times as high as that of the state-of-the-art commercial TIM, demonstrating the superior ability to solve the interfacial heat transfer issues in electronic systems.

The aim of this study was to improve the mechanical properties of Al 2 O 3 ceramics by the addition of Y 2 O 3 -stabilized ZrO 2 whiskers (designated as Al 2 O 3 /YSZ W composite) through the flux method and hot-pressing technology. The effect of YSZ W content on their microstructure , phase composition and transformability, mechanical properties, and wear resistance was systematically investigated. The Al 2 O 3 /YSZ W composites containing 10 wt% YSZ W exhibited the best mechanical performance, including the highest content of YSZ W tetragonal phase and transformability as well as the largest values in their relative density (99.5%), hardness (1969 HV), fracture toughness (9.57 MPa m 1/2 ) and flexural strength (855 MPa). The strengthening and toughening of the Al 2 O 3 /YSZ W composites were attributed to the YSZ W tetragonal-monoclinic phase transformation as well as the whiskers reinforcing effect. Furthermore, the Al 2 O 3 /YSZ W composites also showed the highest friction and wearing properties.

Measurement and quantification of defects are the key challenges for eddy current pulsed thermography (ECPT), localization and detection of surface, sub-surface defects, and the quantification of the defects under complex geometry in particular. To address this issue, this paper proposed a 3D eddy current pulsed thermography system by integration the ECPT system with an RGB-D (3D point cloud with RGB texture information) camera. The thermal image is mapped with the RGB-D image via matched features from the thermal and visible image. In order to establish reliable key-point matches for multi-spectrum image registration, a new shape constrained scale-invariant feature transform (SCSIFT) descriptor is proposed, which adds global shape information to SIFT descriptor. The experimental study has validated that the developed feature matching algorithm for the mapping of the thermal image with RGB-D image. The newly developed 3D ECPT system provides quantified data, including 3D heat distribution and the 3D spatial relationship between defect position, the excitation coil, and the whole specimen, which shows its potential of quantitative evaluation of the defect characteristics.

Highly cross-linked porous NiCo2S4 nanosheets arrays are synthesized by a high-efficiency hydrothermal conversion from the preformed electrodeposited NiCo2O4 arrays. By using thioacetamide as the sulfur source, the electrodeposited NiCo2O4 is directly converted into NiCo2S4 nanosheets arrays without high-temperature sulfurization. Higher porosity and better electrical conductivity are obtained for the NiCo2S4 nanosheets arrays. In addition, reduced diffusion paths of electrons/ions and alleviated volume expansion during cycling are achieved due to the unique porous structure of NiCo2S4. Consequently, as the cathode of alkaline batteries, the obtained NiCo2S4 nanosheets arrays show better electrochemical performance with a high specific capacity (83.5 mAh g−1 at 0.5 A g−1) and better cycling stability (capacity retention of 93% after 5000 cycles) than the NiCo2O4 counterpart arrays (40.3 mAh g−1 at 0.5 A g−1). Our work demonstrates that sulfurization on binary metal oxides can greatly enhance electrochemical performance and shows a new way for construction of advanced electrodes for high-rate batteries.

Colored titanium dioxide (TiO2) nanocrystals have been studied intensively in recent years due to their substantial solar-driven photocatalytic activities. Because of the scarcity of information co...

A LiFePO4/C material with different amounts of iron phosphides was synthesized by a sol–gel method with different calcination temperatures. XRD, HRTEM, SEM, FTIR, BET, Raman, and magnetic measurements were carried out to characterize the physical properties of the LiFePO4/C, while EIS, CV, and charge–discharge tests were carried out to characterize the electrochemical performance. It is obtained that the crystallinity, the particle size of the LiFePO4, and the amount of iron phosphides in the sample are the factors that affect the electrochemical performance of the material, where the key factor determining the electrochemical performance varies in different situations. The samples possessing well-crystallized LiFePO4 particles and similar particle size demonstrated improved rate performance with the increasing amount of iron phosphides when the calcination temperature increased from 650 to 750 °C. The results showed that the rate performance could be improved by harmonious improvement of the ionic conductivity of Li+ and the electronic conductivity.

It is important but challenging to design and fabricate an efficient and cost-effective electrocatalyst for the oxygen evolution reaction (OER). Herein, we report free-standing 3D nickel arrays with a cross-linked porous structure as interesting and high-performance electrocatalysts for OER via a facile one-step electrodeposition method. The 3D nickel arrays are strongly anchored on the substrate, forming self-supported electrocatalysts with reinforced structural stability and high electrical conductivity. Because of their increased active surface area, abundant channels for electron/ion transportation and enhanced electronic conductivity, the designed 3D nickel arrays exhibit superior electrocatalytic OER performance with a low overpotential (496 mV at 50 mA cm−2) and a small Tafel slope (43 mV dec−1) as well as long-term stability (no decay after 24 h) in alkaline solution. Our proposed rational design strategy may open up a new way to construct other advanced 3D porous materials for widespread application in electrocatalysis.

This work explores an alternative vapor sensing mechanism through analyzing dynamic desorption process from butterfly wings for the differentiation of both individual and mixed vapors quantitatively. Morpho butterfly wings have been used in differentiating individual vapors, but it is challenging to use them for the differentiation of mixed vapor quantitatively. This paper demonstrates the use of Morpho butterfly wings for the sensitive and selective detection of closely related vapors in mixtures. Principal components analysis (PCA) is used to process the reflectance spectra of the wing scales during dynamic desorption of different vapors. With the desorption-based detection mechanism, individual vapors with different concentrations and mixed vapors with different mixing ratios can be differentiated using the butterfly wing based sensors. Both the original butterfly wings and butterfly wings with surface modification show the capability in distinguishing vapors in mixtures, which may offer a guideline for further improving selectivity and sensitivity of bioinspired sensors.

In order to overcome the shortcomings of ZnO-based anode materials for lithium-ion batteries, the electrode is designed as a nanostructure of interconnected nickel nanowall-supported ZnO film. The introduction of Ni increases the consumption of Li2O during the first charge process due to the conversion reaction between Ni and Li2O, and thus increases the initial coulombic efficiency. Interconnected Ni nanowalls work as a three-dimensional skeleton to enhance the strength of the film and the mechanical/electrical contact with the substrate, and thus improve the cycling and rate performance. The electrochemical performance of this ZnO/Ni composite is enhanced compared to pure ZnO and many other ZnO-based anode materials, confirming that the electrode structure design is effective.

This paper demonstrates a facile solar steam generator for the generation of high-temperature steam at ambient pressure. The steam generator consists of a coiled copper tube (CCT) that serves as both solar collector and vapor heater. Both the inner and outer surfaces of the CCT are coated with black superhydrophobic copper oxide layer to improve the solar absorption, and such superhydrophobic layer prevents the condensation and clogging of water vapor during the heating process. Solar vapor is generated at the inlet of CCT through interfacial evaporation and subsequently heated inside the CCT as the vapor travels from the inlet to the outlet. By employing this approach, steam temperature that exceeds 100 °C under 1-sun illumination is demonstrated. Furthermore, steam temperature could reach as high as 250 °C under 10-sun illumination at ambient pressure. Successful sterilization experiment was also performed in this work to demonstrate the potential application of the high temperature steam generated. Such demonstrated approach helps open up the potential usage of solar-driven interfacial evaporation in applications that involve high-temperature steam, including medical sterilization, chemical manufacturing and food processing. Keywords: High-temperature steam, Photothermal conversion materials, Solar steam generation, Sterilization, Vapor heating

Solar-driven interfacial evaporation, as one of the most effective ways to convert and utilize solar energy, has attracted lot of interest recently. Most of the previous research studies, however, mainly focused on nonpatterned solar absorbers by improving the structural and chemical characteristics of the solar absorbers used in the interfacial evaporation systems. In this work, we investigated the influence of patterned surface on the evaporation performance of solar absorbers. The patterned surfaces studied, which include black patterns and white patterns, were achieved by selectively printing carbon black on the air-laid paper. Such a design leads to the lateral temperature differences between adjacent patterns of the solar absorber under solar illumination. The temperature differences result in the lateral heat and mass transfer between those patterns, which can effectively accelerate solar-driven vapor generation. With similar patterns and same coverage of carbon black, the increase in the circumference of the surface patterns leads to the increase in the evaporation performance. Additionally, we found that the evaporation performance can be optimized through the design of surface patterns, which demonstrates the potential in reducing the usage of the light-absorbing materials in the solar absorber. The findings in this work not only expand the understanding of the interfacial evaporation systems but also offer additional guidelines in designing interfacial evaporation systems.

Herein, MoO3 nanowires (Fe–MoO3 NWs) along the [110] direction were successfully synthesized in the presence of Fe3+ cations. The Fe–MoO3 NWs present a large specific surface area of 174.7 m2 g−1 and rich surface –OH groups, and the possible formation mechanism of such a structure is due to the adsorption of Fe3+ cations toward non-(110) planes of MoO3 in solution with pH greater than its isoelectric point. The obtained Fe–MoO3 NWs show excellent and highly selective adsorption capacity toward quasi-phenothiazine dyes (methylene blue, toluidine blue, azure I, and acridine orange). The dye removal rate could reach 99% in 3 min, and the maximum adsorption capacity is up to 144.3 mg g−1 and the adsorption is up to 28.86 mg g−1 per minute, which is 11 times greater than that of pure MoO3 and far greater than that of the recently reported MoO3 nanostructures. This excellent selective adsorption performance of Fe–MoO3 NWs was mainly attributed to the enhanced chemical adsorption of quasi-phenothiazine dyes by rich surface –OH groups and Fe species through hydrogen bond and coordination bond adsorption with N and S, respectively, which was confirmed by adsorption isotherms and adsorption kinetics. These results suggest the potential application of Fe–MoO3 NWs in the field of water pollution treatment.

Redox catalysis, including photocatalysis and (photo)electrocatalysis, may alleviate global warming and energy crises by removing excess CO2 from the atmosphere and converting it to value-added resources. Nano-to-atomic two-dimensional (2D) materials, clusters and single atoms are superior catalysts because of their engineerable ultrathin/small dimensions and large surface areas and have attracted worldwide research interest. Given the current gap between research and applications in CO2 reduction, our review systematically and constructively discusses nano-to-atomic surface strategies for catalysts reported to date. This work is expected to drive and benefit future research to rationally design surface strategies with multi-parameter synergistic impacts on the selectivity, activity and stability of next-generation CO2 reduction catalysts, thus opening new avenues for sustainable solutions to climate change, energy and environmental issues, and the potential industrial economy.

As a promising non-destructive testing (NDT) method, magnetic flux leakage (MFL) testing has been widely used for steel structure inspection. However, MFL testing still faces a great challenge to detect inner defects. Existing MFL course researches mainly focus on surface-breaking defects while that of inner defects is overlooked. In the paper, MFL course of inner defects is investigated by building magnetic circuit models, performing numerical simulations, and conducting MFL experiments. It is found that the near-surface wall has an enhancing effect on the MFL course due to higher permeability of steel than that of air. Further, a high-sensitivity MFL testing method consisting of Helmholtz coil magnetization and induction coil with a high permeability core is proposed to increase the detectable depth of inner defects. Experimental results show that inner defects with buried depth up to 80.0 mm can be detected, suggesting that the proposed MFL method has the potential to detect deeply-buried defects and has a promising future in the field of NDT.

While metal-based electrocatalysts have garnered extensive attention owing to the large variety of enzyme-mimic properties, the search for such highly-efficient catalysts still relies on empirical explorations, owing to the lack of predictive indicators as well as the ambiguity of structure-activity relationships. Notably, surface electronic structures play a crucial role in metal-based catalysts yet remain unexplored in enzyme-mimics. Herein, the authors investigate the electronic structure as a possible indicator of electrocatalytic activities of H2 O2 decomposition and glucose oxidation using Pd@Pt core-shell nanocrystals as a well-defined platform. The electron densities of the Pd@Pt are modulated with the correlation of strain through precise control of surface orientation and the number of atomic layers. The close relationships between the electrocatalytic activities and the surface charge accumulation are found, in which the increase of the electron accumulation can enhance both the enzyme-mimic activities. As a result, the Pd@Pt3L icosahedra with compressive strain in Pt shells exhibit the highest electrocatalytic activities for H2 O2 decomposition and glucose oxidation. Such systematic and comprehensive study provides the structure-activity relationships and paves a new way for the rational design of metal-based electrocatalysts. Especially, the charge accumulation degrees may serve as a general performance indicator for metal-based catalysts.

As an excellent electrocatalyst, platinum (Pt) is often deposited as a thin layer on a nanoscale substrate to achieve high utilization efficiency. However, the practical application of the as-designed catalysts has been substantially restricted by the poor durability arising from the leaching of cores. Herein, by employing amorphous palladium phosphide (a-Pd-P) as substrates, we develop a class of leaching-free, ultrastable core-shell Pt catalysts with well-controlled shell thicknesses and surface structures for fuel cell electrocatalysis. When a submonolayer of Pt is deposited on the 6 nm nanocubes, the resulting Pd@a-Pd-P@PtSML core-shell catalyst can deliver a mass activity as high as 4.08 A/mgPt and 1.37 A/mgPd+Pt toward the oxygen reduction reaction at 0.9 V vs the reversible hydrogen electrode and undergoes 50 000 potential cycles with only ∼9% activity loss and negligible structural deformation. As elucidated by the DFT calculations, the superior durability of the catalysts originates from the high corrosion resistance of the disordered a-Pd-P substrates and the strong interfacial Pt-P interactions between the Pt shell and amorphous Pd-P layer.

Objective Rapid urbanization has led to reduced greenness in many areas, this has been linked to adverse health outcomes. The aim was to determine the association between residential greenness experienced during very early childhood with preschool myopia and astigmatism and to explore the potential mediating role of screen time on any associations. Method Information regarding socio-demographic characteristics, home address, screen time during early childhood, and refraction data from vision screenings of 53,575 preschoolers from Longhua Child Cohort Study were collected via questionnaires. Residential greenness was calculated as the average of satellite-derived Normalized Difference Vegetation Index in buffers of 100, 250, and 500 m around each child's home address. Logistic and linear regression models were used to examine the relationships between residential greenness, screen time, and preschool myopia and astigmatism. Result The mean (SD) age of the 53,575 preschoolers was 5.0 (0.7) years, and 24,849 (46.4%) were girls. A total of 1236 (2.3%) preschoolers had myopia and 5347 (10.0%) had astigmatism. In the adjusted model, a higher neighborhood greenness level within 100 m buffers around the home address was associated with decreased risk of myopia (adjusted odds ratios (AOR): 0.62, 95% confidence interval (CI): 0.38–0.99), and higher neighborhood greenness levels within 100, 250, and 500 m decreased the risk of astigmatism, and their AORs (95% CIs) were 0.55 (0.43–0.70) for 100 m, 0.59 (0.41–0.83) for 250 m, 0.61 (0.42–0.90) for 500 m, respectively. Greater screen time during early childhood increased the risk of myopia (AOR = 1.33) and astigmatism (AOR = 1.23). Reduction in screen time fully mediated the benefits of greater residential greenness on preschool myopia, but partially mediated that on preschool astigmatism (p Conclusion Higher residential greenness reduces the risk of preschool myopia and astigmatism; the benefits of residential greenness were mediated through reduced daily screen time.

Stresses have great influences on the mechanical performance and corrosion resistance of pipelines. Magnetic Barkhausen noise (MBN) as an effective non-destructive testing method for evaluating stress in ferromagnetic materials has been widely studied in recent decades. Different from traditional MBN methods based on a time-varying magnetic field, this paper proposed a novel MBN method to induce Barkhausen noise based on rotating permanent magnets, which achieves efficient stress measurement in pipelines. Under different rotating speeds, the characterization of surface tangential excitation field induced by rotating permanent magnets are analyzed by Hall measurements and extrapolation method. Experimental results validate that the proposed method has a good detectability and sensitivity of stress measurement in pipelines.

With the increasing design requirements of grid-connected microgrid, the capacity configuration of microgrid should not only consider the cost, but also consider other design objectives, uncertainty of renewable energy and load demand. Therefore, a multi-objective function considering annual comprehensive cost and grid dependence is established. The k-medoids method was used to obtain the data and probability of typical and extreme days, which was added into the optimization as uncertain scenes. The Multi-Objective Cuckoo Search algorithm (MOCS) is used to solve the proposed model. Then the obtained non-dominated optimal solution set was treated with Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) method, which can obtain the optimal compromise solution from the set. The optimal compromise solution is the final configuration of this Wind-PV-Battery microgrid.

For efficient electrolysis of water for hydrogen generation or other value-added chemicals, it is highly relevant to develop low-temperature synthesis of low-cost and high-efficiency metal sulfide electrocatalysts on a large scale. Herein, we construct a new core-branch array and binder-free electrode by growing Ni

Engineering defects in crystalline electrocatalysts is an effective approach to tailor the electronic structure and number of active sites, which are essential for the intrinsic activity of the hydrogen evolution reaction (HER). Unlike previously reported methods, we demonstrate a confinement effect using a mesoporous template for in situ fabrication of cationic W vacancies in as-prepared ordered mesoporous tungsten phosphide (WP) nanostructures by adjusting the nonstoichiometric ratio of the precursor elements. With a plenty of W vacancies and ordered mesoporosity, the as-prepared catalyst WP-Mesop exhibits better catalytic performance than the catalysts without mesopores and/or vacancies. The WP-Mesop shows an ultralow overpotential of 175 mV in acid and 229 mV in alkaline at 100 mA cm-2 and stability of 48 h without structural collapse in both acid and alkaline media. Meanwhile, density functional theory calculations further reveal that the activation barrier for HER can be lowered by introducing cationic W vacancies. This strategy can be extended to generate cationic defects in other transition metal phosphides to improve their HER activities.

Ion migration has been recognized as a critical step in determining the performance of numerous devices in chemistry, biology, and material science. However, direct visualization and quantitative investigation of solid-phase ion migration among anisotropic nanostructures have been a challenging task. Here, we report an in-situ ChemTEM method to quantitatively investigate the solid-phase ion migration process among coassembled nanowires (NWs). This complicated process was tracked within a NW and between NWs with an obvious nanogap, which was revealed by both phase field simulation and ab initio modeling theoretical evaluation. A migration "bridge" between neighboring NWs was observed. Furthermore, these new observations could be applied to migration of other metal ions on semiconductor NWs. These findings provide critical insights into the solid-phase ion migration kinetics occurring in nanoscale systems with generality and offer an efficient tool to explore other ion migration processes, which will facilitate fabrication of customized and new heteronanostructures in the future.

Semisynthetic artemisinins and other bioactive peroxides are best known for their powerful antimalarial activities, and they also show substantial activity against schistosomes-another hemoglobin-degrading pathogen. Building on this discovery, we now describe the initial structure-activity relationship (SAR) of antischistosomal ozonide carboxylic acids OZ418 (2) and OZ165 (3). Irrespective of lipophilicity, these ozonide weak acids have relatively low aqueous solubilities and high protein binding values. Ozonides with para-substituted carboxymethoxy and N-benzylglycine substituents had high antischistosomal efficacies. It was possible to increase solubility, decrease protein binding, and maintain the high antischistosomal activity in mice infected with juvenile and adult Schistosoma mansoni by incorporating a weak base functional group in these compounds. In some cases, adding polar functional groups and heteroatoms to the spiroadamantane substructure increased the solubility and metabolic stability, but in all cases decreased the antischistosomal activity.

This paper presents a pyroelectric approach for the synthesis of metal–BaTiO3 hybrid nanoparticles (NPs) and demonstrates the enhanced performance on the degradation of dye solution using such hybr...

Lithium-sulfur batteries (LSBs) are considered to be one of the most promising alternatives to the current lithium-ion batteries (LIBs) to meet the increasing demand for energy storage owing to their high energy density, natural abundance, low cost, and environmental friendliness. Despite great success, LSBs still suffer from several problems, including undermined capacity arising from low utilization of sulfur, unsatisfactory rate performance and poor cycling life owing to the shuttle effect of polysulfides, and poor electrical conductivity of sulfur. Under such circumstances, the design/fabrication of porous carbon-sulfur composite cathodes is regarded as an effective solution to overcome the above problems. In this review, different synthetic methods of porous carbon hosts and their corresponding integration into carbon-sulfur cathodes are summarized. The pore formation mechanism of porous carbon hosts is also addressed. The pore size effect on electrochemical performance is highlighted and compared. The enhanced mechanism of the porous carbon host on the sulfur cathode is systematically reviewed and revealed. Finally, the combination of porous carbon hosts and high-profile solid-state electrolytes is demonstrated, and the challenges to realize large-scale commercial application of porous carbon-sulfur cathodes is discussed and future trends are proposed.

To achieve high-speed scanning of defect detection, this paper proposes a motion-induced eddy current (MIEC) thermography method, which utilizes the relative movement between permanent magnet array and the inspected object to induce the eddy current. Specifically, a set of circumferentially arranged permanent magnets rotating in a steel pipe is used to implement the proposed method. Numerical simulation and experimental studies are conducted to investigate the MIEC and thermal distribution influenced by speed, crack orientation, and lift-off effects. The results show that thermal contrast of the crack rises with its orientation to MIEC flowing path changing from parallel to perpendicular; thermal contrast decreases sharply with the lift-off distance of the magnet array increasing. One merit of the proposed MIEC thermography is that MIEC intensity (thermal contrast) increases with scanning speed and benefits the defect detection.

Lithium-ion batteries, with high energy density (up to 705 Wh/L) and power density (up to 10,000 W/L), exhibit high capacity and great working performance. As rechargeable batteries, lithium-ion batteries serve as power sources in various application systems. Temperature, as a critical factor, significantly impacts on the performance of lithium-ion batteries and also limits the application of lithium-ion batteries. Moreover, different temperature conditions result in different adverse effects. Accurate measurement of temperature inside lithium-ion batteries and understanding the temperature effects are important for the proper battery management. In this review, we discuss the effects of temperature to lithium-ion batteries at both low and high temperature ranges. The current approaches in monitoring the internal temperature of lithium-ion batteries via both contact and contactless processes are also discussed in the review. Keywords: Lithium-ion battery, Temperature effect, Internal temperature, Battery management, Thermal management

The commercialization of proton-exchange membrane fuel cells (PEMFCs) is hindered by the extensive use of expensive Pt catalysts due to the sluggish kinetics of oxygen reduction reaction (ORR) at the cathode. This report presents a new strategy to boost ORR through photovoltaic (PV)-driven potential manipulation with a hybrid device that combines PV and fuel cell (FC). Rotating disk electrode (RDE) tests show that the ORR performance of the Pt catalyst has been improved by 2–3 orders of magnitude with this new strategy. This configuration also displays better performance for higher applied potential and for less Pt loading. For PV-driven FC, large enhancement of output power has been demonstrated, which shows the boosting of the output power from FC through the potential manipulation using PV. The combination can boost the output of performance, which is due to the capability of potential manipulation by PV. This is not the effect that can be solely achieved by the simple sum of outputs of a PEMFC with a PV, but the result of the combination of such two different output characteristic power sources, which was boosted especially by the advantage of the light controlled PV. A model FC/PV hybrid device was used to demonstrate the potential application of such enhancement in solar-hydrogen hybrid electric vehicle.

As a ubiquitous solar-thermal energy conversion process, solar-driven evaporation has attracted tremendous research attention owing to its high conversion efficiency of solar energy and transformative industrial potential. In recent years, solar-driven interfacial evaporation by localization of solar-thermal energy conversion to the air/liquid interface has been proposed as a promising alternative to conventional bulk heating-based evaporation, potentially reducing thermal losses and improving energy conversion efficiency. In this Review, we discuss the development of the key components for achieving high-performance evaporation, including solar absorbers, evaporation structures, thermal insulators and thermal concentrators, and discuss how they improve the performance of the solar-driven interfacial evaporation system. We describe the possibilities for applying this efficient solar-driven interfacial evaporation process for energy conversion applications. The exciting opportunities and challenges in both fundamental research and practical implementation of the solar-driven interfacial evaporation process are also discussed. The thermal properties of solar energy can be exploited for many applications, including evaporation. Tao et al. review recent developments in the field of solar-driven interfacial evaporation, which have enabled higher-performance structures by localizing energy conversion to the air/liquid interface.

Lithium (Li) metal is extremely attractive for rechargeable high–energy density batteries, but suffers from uncontrolled dendrite growth, infinite relative volume change and poor solid electrolyte interphase (SEI). Herein, we report large-scale fabrication of lithium−graphite hybrid (LGH) anodes through a facile one-step stirring molten process. Li metal shell is uniformly combined with commercial graphite core forming high-quality LGH anodes. Impressively, the mass loading of Li metal can be precisely controlled in the LGH and avoids vast excess of Li in full cells. Compared to plain Li foil, the as-obtained LGH possesses stable graphite hosts for Li metal and can effectively reduce local current density during stripping/plating process, thus mitigating dendrite formation and stabilizing interface. Consequently, symmetric cell with LGH electrodes exhibit ultra-stable cycling and low polarization even in carbonate electrolytes. The LGH shows stable operation at 5 mA cm−2 for 100 cycles, with a capacity of 1.5 mAh cm−2 and Li utilization of 25% per cycle. Furthermore, the LGH–Li4Ti5O12 prototype cells are further demonstrated with highly improved capacity retention. All these superiorities make the LGH as promising anodes for next-generation high-performance electrochemical energy storage.