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Protein adsorption preferentially occurs and significantly affects the physicochemical reactions once the biodegradable magnesium alloys as bone replacements have been implanted. To date, interactions mechanisms between Mg implants and proteins remain unclear at a molecular level. Thereby, a combination of molecular dynamic (MD) simulations and experimental exploration is used to investigate the adsorption behavior and conformational change of bovine serum albumin (BSA), a representative protein of blood plasma, upon the surface of micro-arc oxidation (MAO) coated Mg alloy AZ31. The influences of absorbed proteins on the cytocompatibility of MAO coating are evaluated by virtue of cytotoxicity assay. Results indicate that the negatively charged O atoms (BSA) exhibit strong interaction with Mg2+ ions of Mg(OH)2, revealing that BSA molecules are ionically adsorbed on the AZ31 surface. Interestingly, MD simulation reveals that MAO coating demonstrates superior ability to capture BSA molecules during the process of adsorption owing to strong electric attraction between the negatively charged O atoms in BSA molecules with Mg atoms of MgO in MAO coating. Moreover, the α-helix part of absorbed BSA molecules on AZ31 substrate and MAO coating markedly decreases with an increase in β-sheet, β-turn and unordered contents, which is attributed to the reduction in the number of hydrogen bonds in BSA molecules. Furthermore, the adsorbed BSA molecules improve the cytocompatibility of MAO coating since the positively charged -NH3+ group and β-sheet content of absorbed BSA molecules mediate the cell adhesion by interacting with the negatively charged cell membrane.

Granular bed filters can effectively filter adhesive dust in high-temperature flue gas. In this study, polyvinyl chloride (PVC) powder was used as adhesive dust, and the mixture of PVC and ash powder was used to simulate solid and adhesive mixed dust. The effects of gas temperature, velocity, and inlet adhesive dust mass content on dust distribution in granular bed (GBF) were discussed. Results show that the mixed dust mainly accumulates on the upper part of the granular bed, and the mass of the collected dust decreases exponentially from the upper layer to the bottom layer in the GBF. The adhesive dust content collected in each layer differs from that of the incoming dust, and their deviation varies approximately linearly along with the depth of the bed. The total dust distribution and adhesive dust content deviation are influenced by gas temperature and inlet adhesive dust content but independent of gas velocity. The correlations of dust distribution of solid and adhesive mixed dust are presented based on the experimental results.

Air-cored planar inductors play an important part in enabling high power-density, low weight, and low-profile design of high-frequency switched-mode power applications. However, the absence of ferromagnetic core in these inductors makes the magnetic field distribution in them different from that in the cored inductors and the transformers. Due to this difference, the conventional winding loss calculation models like the one-dimensional Dowells model are not suitable for these inductors. Therefore, in this paper, an improved two-dimensional analytical winding loss model for multi-layered air-cored inductors with a single-turn per layer is proposed based on the fundamental electromagnetic field solution incorporating the two-dimensional boundary values and the edge effect in its formulation. The finite element method (FEM) simulation and experimental results validate the proposed model's high-accuracy and engineering precision over a wide frequency range (up to 10MHz). Furthermore, the results ensure the proposed analytical model to be an efficient, easier, and better substitute for the FEM based calculation approach.

Due to the electrical, thermal, and mechanical stress, the insulating materials of cable undergo a slow aging process in service, which leads to the decline of insulation performance. Besides, friction frequently occurs when the cable is moving or vibrating, which will easily cause mechanical damage including frays and chafes. Both aging and damage will cause the characteristic impedance to change. Therefore, it is of great significance for the safe operation of the cable to analyze the variations of characteristic impedance and to make an effective diagnosis. In this paper, a two-dimensional model of the cable containing defects is firstly built, and the characteristic impedance of the model is calculated by the finite element method (FEM). Meanwhile, a quantitative analysis of the characteristic impedance under two defect types is carried out. Secondly, combining the space-time focusing of time-reversal and the time-frequency characteristics of reflectometry, the time-reversal time-frequency domain reflectometry (TRTFDR) is proposed to diagnose the cable faults. Based on the distributed parameters calculated by the FEM, the TRTFDR simulation model is established to study the judgment of different faults. Finally, the validity of this method is verified by experiments.

Combining suitable microstructure and dielectric-magnetic synergy effect is conducive to achieve lightweight, broadband, and high-efficiency microwave absorbing materials within low filler loading. Herein, porous carbon polyhedrons coupled with bimetallic CoNi alloys were synthesized by using metal-organic frameworks (MOFs) as a template and subsequent pyrolysis treatment. Electromagnetic analysis indicated that the existence of metal Ni element could influence the wave attenuation capacity effectively, resulting in frequency selective wave absorption performance. Additionally, the pyrolysis temperature was also closely related to wave absorption intensity. The Co2Ni1/C/PVDF composites calcined at 800 °C possessed outstanding wave absorption performance at an ultra-low filler loading of 5 wt%. The minimum reflection loss value achieved -52 dB (10.8 GHz) under the matched thickness of 3 mm. Moreover, the broadest effective absorption bandwidth (RL

The energy-conversion storage systems serve as crucial roles for solving the intermittent of sustainable energy. But, the materials in the battery systems mainly come from complex chemical process, accompanying with the inevitable serious pollutions and high energy-consumption. Natural mineral resources display various merits, such as unique architecture, adsorption capability and rich active sites, which have captured numerous attentions with remarkable advancements. Recently, the minerals compounds, containing 1D structure (halloysites, attapulgites, sepiolite), 2D structure (montmorillonite, vermiculite, molybdenite) and 3D structure (diatomite, pyrites), have been applied in plenty of fields. Aiming at their energy-storage applications, the significant utilizations in electrodes, separators, electrolyte and metal-protection were detailedly reviewed in lithium-ions battery, lithium-sulfur battery, solid-state battery and so on. However, it should be acknowledged that, the simple minerals hardly meet the demand of energy-storage systems, due to their inferior conductivity and less active substances. Thus, series of modified manners are applied for the evolution of phase (from silicate mineral to Si), the incorporating with carbon/polymer and the tailoring of surface traits, which were in-depth discussed as following. The work was expected to summarize the traits about mineral compounds from different architectures, whilst offering significant guidelines for exploring mineral-based materials in energy-storage systems.

A gradient nano self-lubricating ceramic cutting tool material was prepared by vacuum hot-pressing sintering technique. The composition of each layer is designed in a gradient so that the nano-sized solid lubricant content is gradually reduced from the surface to the center, and residual compressive stresses are formed in the tool surface. The components and microstructure of the prepared ceramic tools showed gradient changes, with clear and well-bonded interfaces between the gradient layers. Compared with the mechanical properties of homogeneous tool, the flexural strength, fracture toughness, and hardness of this ceramic tool were increased by 74.0%, 3.9%, and 5.0%, respectively. The gradient design had little effect on the friction coefficient, but the improved mechanical properties and the presence of residual compressive stresses in the surface layer improved the wear resistance of the tool. The higher the friction speed and load, the more effectively the gradient design will improve the wear rate.

Scalable fabrication of membrane substrates, having high strength, customizable pore size, high gas and water permeation, has been key issue in recent years due to the rapid growth of engineered separation processes. This work provides a novel fabrication method for porous Al2O3 membrane substrates (PAS) by using suspension emulsions as pore forming agents and gel-tape-casting as a shaping method. The substrates displayed a smooth surface and a porous internal structure. By adjusting the volume ratio of water and oil from 1:1 to 1:4, the average pore size increased from 0.53 to 1.06 μm. Moreover, the porosity increased from 50.7% to 75.8%, in contrast, the bending strength decreased from 46.7 ± 1.5 to 17.3 ± 1.1 MPa. In addition, the permeability of the N2 and water was improved from 8.13 × 105 to 5.10 × 106 L m−2 h−1 bar−1 and 5.02 × 103 to 1.84 × 104 L m−2 h−1 bar−1 respectively and as a result, this can qualify the membranes for a wide range of applications.

Poly(ethylene oxide) (PEO) and its derivatives based gel polymer electrolytes (GPEs) are severely limited in advanced and safe lithium-ion batteries (LIBs) owing to the intrinsically high flammability of liquid electrolytes and PEO. Directly adding flame retardants to the GPEs can suppress their flammability and thus improve the safety of LIBs, but results in deteriorative electrochemical performance. Herein, a novel GPE with chemically bonded flame retardant (i.e. diethyl vinylphosphonate) in cross-linked polyethylene glycol diacrylate matrix, featuring both high-safety and high-performance, is designed. This as-prepared GPE storing the commercial 1 mol L−1 LiPF6 electrolyte resists high temperature of 200 °C and cannot be ignited as well as possesses a high ionic conductivity (0.60 mS cm−1) and good compatibility with lithium. Notably, the LiFePO4/Li battery with this GPE delivers a satisfactory capacity of 142.2 mA h g−1 and a superior cycling performance with a capacity retention of 96.3% and a coulombic efficiency of close to 100% for 350 cycles at 0.2 C under ambient temperature. Furthermore, the battery can achieve steady charge–discharge for 100 cycles with a coulombic efficiency of 99.5% at 1 C under 80 °C and run normally even at a high temperature of 150 °C or under the exposure to butane flame. Differential scanning calorimetry manifests significantly improved battery safety compared to commercial battery systems. This work provides a new pathway for developing next-generation advanced LIBs with enhanced performance and high safety.

Riboflavin (RF) is one of the necessary vitamins. If human body lacks RF, it will lead to inflammation and dysfunction of mouth, lips and skin. Thus sensitive and accurate determination of RF is necessary. Here, an electroactive covalent-organic framework nanobelt (COFTFPB-Thi) with thickness of 1.4 nm was prepared by amine-aldehyde condensation reaction between thionine and 1, 3, 5-tris (p-formylphenyl) benzene, which was then grown vertically on three-dimensional porous carbon derived from kenaf stem (3D-KSC) for double signal ratiometric electrochemical detection of RF. The resulted 3D-KSC/COFTFPB-Thi showed two reduction peaks at −0.08 V and −0.23 V, which came from the reduction of COFTFPB-Thi and the conjugated structure of COFTFPB-Thi, respectively. In the presence of RF, those RF molecules near the electrode surface were oxidized at 0.6 V. Then some oxidized RF (RFox) adsorbed on COFTFPB-Thi would oxidize COFTFPB-Thi into COFTFPB-Thi(ox) while other RFox adsorbed on 3D-KSC kept unchanged. When the potential was scanned from 0.6 V to −0.6 V, both COFTFPB-Thi(ox) and RFox adsorbed on 3D-KSC were reduced at −0.08 V and −0.45 V accordingly, while the reduction peak of −0.23 V of the conjugated structure of COFTFPB-Thi kept constant. When j-0.45/j-0.23 was used as the response signal, the detection limit was 44 nM and the linear range was 0.13 μM −0.23 mM. By using j-0.08/j-0.23 as the response signal, a detection limit of 90 nM and a linear range of 0.30 μM-0.23 mM (S/N = 3) were obtained. By using double signals, the measurement results can be corrected to make the results more accurate and reliable. The sensor also showed good selectivity, reproducibility and stability, which provided a good application prospects.

Bulk metallic glasses (BMGs) are thermodynamically metastable. As such, crystallization occurs when a BMG is thermally annealed at a temperature above the glass transition temperature. While extensive studies have been performed on the crystallization kinetics of BMGs, most of them have focused on the amorphous-to-crystalline structural ordering, and little attention has been paid to chemical distribution and its relationship with the structural ordering during the crystallization process. In this paper, a new approach, with simultaneous differential scanning calorimetry (DSC) and small angle neutron scattering (SANS) measurements, was applied to study in situ the crystallization of a Zr45.5Cu45.5Al9 BMG upon isothermal annealing at a temperature in the supercooled liquid region. Quantitative analysis of the DSC and SANS data showed that the structural evolution during isothermal annealing could be classified into three stages: (I) incubation; (II) amorphous-to-crystalline structural ordering; (III) continuous chemical redistribution. This finding was validated by composition analysis with atom probe tomography (APT), which further identified a transition region formed by expelling Al into the matrix. The transition region, with a composition of (Cu,Al)50Zr50, served as an intermediate step facilitating the formation of a thermodynamically stable crystalline phase with a composition of (Cu,Al)10Zr7.

Though the function of peptide based nanotubes are well correlated with its shape and size, controlling the dimensions of nanotubes still remains a great challenge in the field of peptide self-assembly. Here, we demonstrated that the shell structure of nanotubes formed by a bola peptide Ac-KI3VK-NH2 (KI3VK, in which K, I, and V are abbreviations of lysine, isoleucine, and valine) can be regulated by mixing it with the salt sodium tartrate (STA). The ratio of KI3VK and STA had a great impact on shell structure of the nanotubes. Bilayer nanotubes can be constructed when the molar ratio of KI3VK and STA was less than 1:2. Both the two hydroxyls and the negative charges carried by STA were proved to play important roles in the bilayer nanotubes formation. Observations of different intermediates provided obvious evidence for the varied pathway of the bilayer nanotubes formation. Based on these experimental results, the possible mechanism for bilayer nanotubes formation was proposed. Such a study provides a simple and effective way for regulating the shell structure of the nanotubes and may expand their applications in different fields.

The development of novel materials with ion-selective nanochannels has introduced a new technology for harvesting salinity gradient (blue) energy, namely nanopore power generators (NPG). In this study, we perform a comprehensive analysis of the practical performance of NPG in both coupon-size and module-scale operations. We show that although NPG membrane coupons can theoretically generate ultrahigh power density under ideal conditions, the resulting power density in practical operations at a coupon scale can hardly reach 10 W·m−2 due to concentration polarization effects. For module-scale NPG operation, we estimate both the power density and specific extractable energy (i.e., extractable energy normalized by the total volume of the working solutions), and elucidate the impact of operating conditions on these two metrics based on the interplay between concentration polarization and extent of mixing of the high- and low-concentration solutions. Further, we develop a modeling framework to assess the viability of an NPG system. Our results demonstrate that, for NPG systems working with seawater and river water, the gross specific extractable energy by the NPG system is very low (~0.1 kW·h·m−3) and is further compromised by the parasitic energy consumptions in the system (notably, pumping of the seawater and river water solutions and their pretreatment). Overall, NPG systems produce very low net specific extractable energy (

The uneven growth of thermally grown oxides (TGOs) in thermal barrier coating systems is an important cause of cracking failure at the coating interface in high-temperature environments. The doping of rare earth elements in the bonding layer can effectively inhibit the formation of spinel oxides in the TGO and improve the high-temperature oxidation resistance of the coating. However, a single rare earth element has a limited effect on inhibiting TGO failure. In this study, a NiCoCrAlYHf coating was prepared using a supersonic flame spraying (HVOF) technique. The effects of HfO2 doping on the high-temperature oxidation behaviour of the coatings and diffusion behaviour of metallic elements in the coatings were investigated at 1100 °C. The results showed that the nano-sized HfO2 filled the pores between the powder particles and improved the hardness of the coating. During the high-temperature oxidation process, the oxides formed by Hf and Y had a large size and low solubility, which effectively blocked the diffusion of Al. This slowed the generation of spinel oxides, effectively inhibited the growth of the TGO, it inhibits the initiation and propagation of cracks within the coating, reduces damage to the coating from tensile and compressive stresses at the interface, and improved the high-temperature oxidation resistance of the coating.

The copper particle size and the interface of Cu and ZnO showed strong impacts on the formation of methanol and CO in CO2 hydrogenation over Cu@ZnO catalysts.

Metal hydrides can theoretically store H2 at extremely low temperatures in anodic nickel-metal hydride batteries (Ni-MHBs). However, the evolution kinetics of H2 was retarded at low temperatures and the H2-storing capacity of the battery was reduced. Annealing temperature was hypothesized to be the key to regulate the phase composition and therefore, improve the electrochemical kinetics and performance in cold operating conditions. A new-type of La1.9Y4.1Ni20.8Mn0.2Al H2-storage alloy was prepared and annealed at 1098, 1148, 1223 and 1323 K. At the annealing temperature of 1148 K, the alloy exhibited various crystalline structures and H2 channel modifications, a high H2 desorption plateau, resistance to oxidation/corrosion and favourable kinetic characteristics. All the measurements was performed at a temperature of 243 K, resulting in a maximum discharge specific capacity of 298.6 mAh g−1, low-temperature discharge rate of 80.5%, and high-rate dischargeability of 62.8% at a current density of up to 300 mA g−1.

To the best of our knowledge, this is the first time to report the preparation of a dotted nanowire arrayed by 5 nm sized palladium and nickel composite nanoparticles (denoted as PdxNiy NPs) via a hydrothermal method using NU and PdO·H2O as the starting materials. The samples prepared at the mass ratio of NU to PdO·H2O 1:1, 1:2 and 2:1 were, respectively, nominated as catalyst c1, c2 and c3. The chemical compositions of all synthesized catalysts were mainly studied by using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), revealing that metallic Ni was one main component of all prepared catalysts. Surprisingly, the main diffraction peaks appearing in the XRD patterns of all prepared catalysts were assigned to the metallic Ni rather than the metallic Pd. Very interestingly, as indicated by the TEM images, a large number of dotted nanowires arrayed by numerous equidistant 5 nm sized nanoparticles were distinctly exhibited in catalyst c1. More importantly, when being used as electrocatalysts for EOR, all prepared catalysts exhibited an evident electrocatalytic activity towards EOR. In the cyclic voltammetry (CV) test, the peak current density of the forward peak of EOR on catalyst c1 measured at 50 mV s−1 was as high as 56.1 mA cm−2, being almost 9 times higher than that of EOR on catalyst c3 (6.3 mA cm−2). Particularly, the polarized current density of EOR on catalyst c1 at 3600 s, as indicated by the chronoamperometry (CA) experiment, was still maintained to be around 1.47 mA cm−2, a value higher than the latest reported data of 1.3 mA cm−2 (measured on the pure Pd/C electrode). Presenting a novel method to prepare dotted nanowires arranged by 5 nm sized nanoparticles and showing the significant eletrocatalytic activities of the newly prepared dotted nanowires towards EOR were the major contributions of this preliminary work.

The development of hydrogen evolution activity (HER) electrocatalyst that can run durably and efficiently under the large current density is of special significance but still challengeable for the massive production of hydrogen. Herein, a CoP/Ni(OH)2 nanowire catalysts grown on Co foam (CF) with a three-dimensional heterojunction structure has been successfully prepared by electrodepositing nickel hydroxide on the surface of cobalt phosphide. The prepared CoP/Ni(OH)2–15 min sample reveals a superior HER activity and stability. It merely requires ultralow overpotentials of 108 and 175 mV to 100 and 500 mA cm−2, respectively. In addition, the long-term stability test shows that the catalyst (CoP/Ni(OH)2–15 min) can operate stably for at least 70 h at 400 mA cm−2. Utilizing NiFe-LDH/IF with high OER activity, the NiFe-LDH/IF || CoP/Ni(OH)2–15 min catalyst system possesses the same outstanding performance for overall water splitting (OWS), which can accomplish ≈ 500 mA cm−2 at 1.74 V in 1 M KOH electrolyte. Moreover, the NiFe-LDH/IF || CoP/Ni(OH)2–15 min couple can work for more than 80 h at 500 mA cm−2, indicating its a great prospect in the area of electrolysis water. Such excellent catalytic performance is mainly attributed to the armor effect of Ni(OH)2, which can not only promote the rapid decomposition of water molecules, but also prevent the loss of phosphorus and enhance the synergistic effect of CoP and Ni(OH)2. This work can offer a significant reference for the design with high-performance and durable transition metal phosphide electrocatalysts.

Developing highly efficient, durable, and non-noble electrocatalysts for the sluggish anodic oxygen evolution reaction (OER) is the pivotal for meeting the practical demand in water splitting. However, the current transition-metal electrocatalysts still suffer from low activity and durability on account of poor interfacial reaction kinetics. In this work, a facile solid-state synthesis strategy is developed to construct transition-metal sulfides heterostructures (denoted as MS2/NiS2, M = Mo or W) for boosting OER electrocatalysis. As a result, MoS2/NiS2 and WS2/NiS2 show lower overpotentials of 300 mV and 320 mV to achieve the current density of 10 mA·cm-2, and smaller Tafel slopes of 60 mV·dec-1 and 83 mV·dec-1 in 1 M KOH, respectively, in comparison with the single MoS2, WS2, NiS2, as well as even the benchmark RuO2. The experiments reveal that the designed heterostructures have strong electronic interactions and spontaneously develop a built-in electric field at the heterointerface with uneven charge distribution based on the difference of band structures, which promote interfacial charge transfer, improve absorptivity of OH-, and modulate the energy level more comparable to the OER. Thus, the designed transition-metal sulfides heterostructures exhibit a remarkably high electrocatalytic activity for OER. This study provides a simple strategy to manipulate the heterostructure interface via an energy level engineering method for OER and can be extended to fabricate other heterostructures for various energy-related applications.

Wearable sensors have been widely studied because of their small size, light weight, and potential for the noninvasive tracking and monitoring of human physiological information. Wearable flexible sensors generally consist of two parts: a flexible substrate in contact with the skin and a signal processing module. At present, wearable electronics cover many fields, such as machinery, physics, chemistry, materials science, and biomedicine. The design concept and selection of materials are very important to the function of a sensor. In this review, we summarize the latest developments in flexible materials for wearable sensors, including developments in flexible materials, electrode materials, and new flexible biodegradable materials, and describe the important role of innovation in material and sensor design in the development of wearable flexible sensors. Strategies and challenges related to the improvement of the performances of wearable flexible sensors, as well as the development prospects of wearable devices based on flexible materials, are also discussed.

Coordination polymers have received immense attention for proton conduction owing to their highly tunable and designable structures. Herein, based on the flexible ligand 5-(4-pyridine)-methoxyisophthalic acid (H2L), two novel highly chemically stable indium coordination polymers (In-CPs), InL(H2O)Cl·H2O (In–L–Cl) and InL(H2O)(NO3) (In–L–NO3), were synthesized through solvothermal methods. In–L–Cl and In–L–NO3 are isostructural, in which every individual In(III) atom connects to L2− to form a single layer, and coordinated Cl− and NO3− are inserted into the windows of the interlayers. Both of them possess high water and chemical stability. More importantly, the abundant Cl− and NO3− exposed in the interlayer can act as hydrogen bond acceptors to facilitate the formation of a dense hydrogen bonding network, thus improving proton transfer efficiently. Electrochemical impedance spectroscopy shows that In–L–Cl and In–L–NO3 display optimized proton conductivities of 1.88 × 10−3 and 1.00 × 10−3 S cm−1 at 100% relative humidity (RH) and 80 °C, respectively. The difference in proton conductivity of In–L–Cl and In–L–NO3 likely stems from the variations in the hydrogen bonding networks formed by lattice water and the different electronegativities of the coordinated anionic functional sites. This study provides an alternative way to prepare highly proton-conductive CPs.

A method of reconstructing the original partial discharge (PD) signal to improve the accuracy of PD localization in cross‐linked polyethylene (XLPE) cables is presented here. XLPE cables, extremely sensitive to PDs, are the most popular underground cables in urban grids. The conventional PD localization methods, based on evaluation of the arrival times of PD pulses in the time domain, are negatively affected by the dispersion and attenuation of PD signals propagating in the power cable. A method for the accurate localization of PDs realized through inverse frequency domain modelling (IFDM) is presented here. The method, eliminating the systematic localization error caused by the dispersion and attenuation, significantly improves the localization accuracy. The locations of the PD are identified by comparing peak values of the initial PD signals reconstructed from different extracted pulses. A method for evaluating the propagation constant of the cable is also presented. The efficiency of the accurate localization method was verified by laboratory experiments. Besides, the inherent limitations of the conventional PD localization method for longer cable tests are discussed. The inevitable location error in the conventional methods does not exist in the new method.

The interfacial reaction between alloys and ceramic materials is an important factor to influence the quality and service performance of the turbine blade. In this paper, three typical height sections of 120mm, 160mm and 210mm were selected, and the interface reactions between DD6 single crystal superalloy and silica based ceramic cores were investigated by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS). The results showed that the infiltration degree of the melt alloy increases with the increase of reaction time. The thickness of the reaction layer could be over 0.3mm when the reaction time increased up to 70min. The main reasons of forming the infiltration layer were the infiltration of the Al element and the interfacial reaction between the Al element and the ceramic core. There formed an aluminum deficient layer on the metal surface because of the interface reaction between the alloy and the ceramic core. The dense layer formed by interfacial reaction on the surface of the core will cause some difficulties for core leaching. Keywords: DD6 single crystal superalloy; Silica based ceramic core; Interface reaction

The interfaces between DZ40M directional solidified superalloy and ceramic mould (SiO2-base core and Al2O3-base shell) was studied by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The results showed that there was a serious interface reaction between DZ40M and ceramic cores，which resulted in many reaction pits (~100μm deep), Si rich residue alloys and Zr rich subglobose oxides on the inner surface. And the interface reaction between DZ40M and ceramic shell induced a ~50μm of pink sand burning layer. The thermal analysis showed that the reactions between DZ40M and core or shell were similar: the active alloy constituents (Zr, Al, Ti and Cr) were oxidized and became oxides or solid solution with the core or shell components (SiO2, Al2O3 or Fe2O3), but the interface characterization of DZ40M/core and DZ40M/shell was different because the shell had the main content of Al2O3 and impurity of Fe2O3, while those of the core were SiO2 and CaO, respectively.

Bone defects accompanied by infection or inflammation can significantly delay the healing process. To simultaneously achieve controlled release of local antibiotics for infection control and bone healing, bone-implantable delivery systems have been considered as a promising strategy. This study aims to improve drug loading capacity of bone-implantable delivery systems by introducing hollow structure mesoporous bioactive glass nanospheres (HMBGs) through a sol–gel process. Particularly, such core–shell bimodal-porous structured nanoparticles were prepared through a sacrificing template using cetyltrimethylammonium bromide (CTAB) as surfactant. It was found that varying the amount of CTAB during the synthesis process is a simple and effective approach for tuning the particle size, morphology, and structure of HMBGs. For in vitro drug release, HMBGs could sustain storage and release of vancomycin hydrochloride (VAN) via diffusion-controlled mechanism, thereby inhibiting the bacteria growth in the subsequent bacterial study. Moreover, HMBGs incorporated with VAN provided a biomimetic microenvironment favored by cell adhesion and proliferation. These findings support the compatibility of HMBG nanoparticles with antibiotics and their potential application in the treatment of infectious bone defects.

Advanced oxidation technology is considered to be the most potential wastewater treatment technology. As one of the advanced oxidation technologies, the three-dimensional electrochemical system (3DES) is often used to treat industrial wastewater that is difficult to degrade. Sulphonated phenolic resin (SMP) was treated as a characteristic pollutant in sulfonated drilling wastewater. The separate effect of current, the dosage of particle electrodes, chloride ion concentration and initial pH on chlorinated by-products were analyzed by response surface methodology (RSM). Results showed that current is the most dominant factor, followed by the dosage of particle electrodes. The ultraviolet-electrolysis (UVEL) system was implemented by adding ultraviolet light under the optimal electrolysis (EL) system. The chemical oxygen demand (CODcr) and total organic carbon (TOC) removal rates of the UVEL system were respectively increased by 19% and 29.39% compared with the EL system, the concentration of chlorinated by-products was also reduced by 534.4 mg/L when the UV irradiance was 5.24 mW/cm2. These results indicated that the UVEL system degrades SMP more thoroughly. The enhanced reaction mechanism of the UVEL system and the possible degradation pathway for SMP were proposed by controlling free radical quenching experiments and the product of EL and UVEL processes. The results showed that the high degradation efficiency of the UVEL system could be attributed to the synergistic degradation mechanism present in the UVEL system, where the photolysis of active chlorine species (ACl) promotes the increase of hydroxyl radical (·OH). HIGHLIGHTS Current is the most important factor affecting ACl change.; ACl is the main active substance to degrade SMP in EL system.; The synergism degradation mechanism existing in the UVEL can be attributed to the additional increase of ·OH.; Less chlorinated by-products were produced in the UVEL degradation system.

There is an urgent need for high-safety and high-energy lithium-ion batteries to satisfy the rapidly increasing need for energy storage. Nickel-rich layered cathodes have been at the forefront of the revolution for batteries due to their relatively high capacity and low cost. However, with the increase of nickel content, the batteries suffer from severe safety concerns, which caused by thermal runaway. Here we show that the ultraconformal cathode-electrolyte interphase (CEI) protective skin with high inorganic content dramatically enhances the safety of high-energy practical Li-ion pouch cells. We find that the robust CEI skin significantly improves the intrinsic thermal stability, mitigates the evolution of oxygen resulting from phase transition, and effectively suppresses the associated parasitic reactions between the delithiated cathodes and electrolyte. The in-situ CEI engineering strategy is simple and suitable for practical industrial manufacture, and it provides design ideas for aggressive nickel-rich cathodes towards safe and high-energy batteries.

Two-dimensional materials are among the most efficient optical materials for Q-switched pulse applications, rising to unprecedented heights. Although the exploration of 2D nanomaterials has attract...

Antimicrobial resistance in Gram-negative bacteria has become one of the leading causes of morbidity and mortality and a serious worldwide public health concern due to the fact that Gram-negative bacteria have an additional outer membrane protecting them from an unwanted compound invading. It is still very difficult for antimicrobials to reach intracellular targets and very challenging to treat Gram-negative bacteria with the current strategies. Here, we found that (o-(bromomethyl)phenyl)boronic acid was incorporated into poly((2-N,N-diethyl)aminoethyl acrylate) (PDEA), forming a copolymer (poly(o-Bn-DEA)) having both phenylboronic acid (B) and ((2-N,N-diethyl)amino) (DEA) units. Poly(o-Bn-DEA) exhibits very strong intramolecular B-N coordination, which could highly promote the covalent binding of phenylboronic acid with lipopolysaccharide (LPS) on the outer membrane of E. coli and lodge poly(o-Bn-DEA) on the LPS layer on the surface of E. coli. Meanwhile, the strong electrostatic interaction between poly(o-Bn-DEA) and the negatively charged lipid preferred tugging the poly(o-Bn-DEA) into the lipid bilayer of E. coli. The combating interactions between covalent binding and electrostatic interaction form a tug-of-war action, which could trigger the lysis of the outer membrane, thereby killing Gram-negative E. coli effectively without detectable resistance.

Increasing the intrinsic conductivity of LiFePO4 can improve its electrochemical performance. Solving this problem can be achieved by P-site doping of LiFePO4 powder. Here, B-Mg co-doped LiFePO4 is successfully synthesized by solvothermal methods. The physical and electrochemical properties of all samples are systematically characterized with various characterization methods. In particular, proper B ion doping is determined to be beneficial to electronic conductivity, which induces the rearrangement of the PO43+ electron cloud. Also, doping with Mg can balance the problems of oxygen vacancies caused by doping B, thereby smoothing the transmission path of lithium ions, resulting in enhanced electrochemical performance. Moreover, XRD and SEM results illustrated that co-doping B and Mg do not change the LiFePO4 structure but promote the formation of a uniform and small particle. Compared with other samples, LiFeMg0.02P0.98B0.02O4 demonstrates superior electrochemical performance, which showed a specific discharge capacity of 147.4 mAh g−1 at 1 C and a corresponding capacity retention rate of 98.6% after 100 cycles. Even at 10 C, the discharge capacity still maintains 114.9 mAh g−1. The results of this work indicate that enhancing electronic conductivity and balancing oxygen vacancy are attributed to high electrochemical performance.

The rational design of the surface structure and morphology characteristics of the catalyst at atomic level are the key to improve the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) in lithium-oxygen (Li-O2) battery. Here a series of cobalt phosphide (CoP) electrocatalysts with a variety of index facets are successfully prepared including concave polyhedrons CoP exposing with (2 1 1) crystal planes (CoP CPHs) spherical nanoparticles CoP exposed with (0 1 1) crystal planes and polyhedron particles CoP exposing with (0 1 1) and (1 1 1) crystal planes. The results show that CoP CPHs based Li-O2 battery presents a large discharge capacity of 33743 mA h g−1 at current density of 50 mA g−1 and a remarkable long cycle life of up to 950 h. The experimental results demonstrates that the CoP CPHs electrode exposing with high-index (2 1 1) facets based Li-O2 battery exhibits an extremely low overpotential (0.67 V) ultrahigh specific capacity (33743 mAh g−1) and remarkable long-term stability of up to 950 h. Most importantly density functional theory (DFT) calculations demonstrate the excellent electrocatalytic activity of high-index (2 1 1) facets as compared to the low-index (0 1 1) and (1 1 1) planes are because of the existence of large density of atomic steps edge ledge sites and kinks which supply a wide space for breaking chemical bonds and increasing the reaction activity for oxygen electrode.

Bifunctional photocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) have attracted growing interest to understand the mechanisms governing different evolution reactions, and the bifunctional activity of a single type of crystalline photocatalyst has gained especial attention. We herein report the high photocatalytic OER and HER activities of Bi2WO6 nanoplates (BWO NPs) which are synthesized by a simple hydrothermal method, and the switchable OER and HER performances controlled by the pH value of the precursor solvent. In the pH range from 4 to 9, the thickness of BWO NPs along the [0 0 1] direction exhibits interesting dependence on the pH value, which decreases as the pH value increases. Correspondingly, the BWO NPs obtained at the pH value of 7 (BWO-7) show the highest photocatalytic OER activity, while the BWO NPs synthesized at the pH value of 9 (BWO-9) exhibit the highest photoactivity towards HER. The electronic band structure analysis indicates that the highest photocatalytic OER activity is related to the band alignment of the valence band maximum of Bi2WO6, which determines the efficient separation of photogenerated electrons and holes as well as the fast charge transfer kinetics. The crystal facet evolution resulting from thickness reduction promotes the exposure of {0 0 1} facets for HER and decreases the exposure of {1 0 0} and {0 1 0} facets for OER. This work provides new insights into the combined effects of crystal facets and electronic band structures on photocatalysis.

Interconnectivity is the key characteristic of bone tissue engineering scaffold modulating cell migration, blood vessels invasion and transport of nutrient and waste. However, efforts and understanding of the interconnectivity of porous Mg is limited due to the diverse architectures of pore struts and pore size distribution of Mg scaffold systems. In this work, biomimetic hierarchical porous Mg scaffolds with tailored interconnectivity as well as pore size distribution were prepared by template replication of infiltration casting. Mg scaffold with better interconnectivity showed lower mechanical strength. Enlarging interconnected pores would enhance the interconnectivity of the whole scaffold and reduce the change of ion concentration, pH value and osmolality of the degradation microenvironment due to the lower specific surface area. Nevertheless, the degradation rates of five tested Mg scaffolds were no different because of the same geometry of strut unit. Direct cell culture and evaluation of cell density at both sides of four typical Mg scaffolds indicated that cell migration through hierarchical porous Mg scaffolds could be enhanced by not only bigger interconnected pore size but also larger main pore size. In summary, design of interconnectivity in terms of pore size distribution could regulate mechanical strength, microenvironment in cell culture condition and cell migration potential, and beyond that it shows great potential for personalized therapy which could facilitate the regeneration process.

Heating tower heat pumps are increasingly used in subtropical areas due to their frost-free characteristics. The spray heating tower (SHT) solves the fouling problem suffered by the packing heating tower and ensures thermal performance. However, the heat and mass transfer characteristics of SHT have not been fully revealed and the power consumption of SHT is higher than that of packing heating towers. In the present study, the effects of tower height, air temperature, solution concentration/type, and liquid to gas ratio on the thermal performance of SHT were analyzed using a mathematical model. The heat and mass transfer characteristics of SHT with 100% thermal efficiency and/or 100% tower effectiveness were investigated. The results showed that when thermal efficiency approached 100% and liquid to gas mass ratio was 0.28, evaporation and condensation occurred at the bottom and top of the tower, respectively. Based on the parametric analysis results, a parameter design strategy to reduce pump power consumption while ensuring thermal performance was determined, which reconciled the contradiction between power consumption and thermal performance of SHT. The results of this investigation may provide a reference for the design and operation of SHT.

The development of low-cost and eco-friendly aqueous electrolytes with a wide voltage window is the key to achieving safe high energy density supercapacitors (SCs). In this work, a molecular crowding electrolyte is prepared by simulating the crowded environment in living cells. Ion transport in the molecular crowding electrolyte can be effectively improved via reducing the molecular weight of the crowding agent, polyethylene glycol (PEG). The results show that PEG with a molecular weight of 200 (PEG200) can significantly improve ionic conductivity while maintaining a wide voltage window. These advantages enable commercial activated carbon-based SCs to work at 2.5 V with high energy density, outstanding rate performance and good stability for more than 10, 000 cycles. On this basis, three series of molecular crowding electrolytes using sodium perchlorate, lithium perchlorate, and sodium trifluoromethanesulfonate as salts are developed, demonstrating the versatility of PEG200 for wide-voltage aqueous electrolytes.

Core-shell particles are considered to be one of the primary strengthening and toughening methods of cermet. In this study, a (W,Ti,Ta)C based cermet was prepared by vacuum hot pressing sintering technology with the addition of c-BN@Al2O3 (Al2O3 coated c-BN). Localized high residual stress around the core-shell particles causes the strengthening and toughening mechanism at short distances behind the crack tip, such as crack deflection, secondary cracks, crack branching, and grain pull-out, even at a small volume fraction of 10 vol%. Compared with cermet without Al2O3 and c-BN, the flexural strength and fracture toughness of the cermet with 10 vol% c-BN@Al2O3 are increased by 35.62% and 28.45%, reaching 1462 ± 49 MPa and 13.68 ± 0.51 MPa m1/2, respectively.

Although transition metal phospho-sulfides deliver outstanding electrochemical performance, complex preparation methods hindered their further development. Herein, we report a facile one-step electrodeposition approach to deposit interconnected nanowalls-like nickel cobalt phospho-sulfide (Ni-Co-P-S) nanosheets onto the surface of carbon cloth. The thin Ni-Co-P-S nanosheets with multi-components and synergetic effects delivered rich active sites, further enhancing reversible capacitance. Therefore, the as-prepared Ni-Co-P-S electrode materials exhibit excellent electrochemical performance in a three-electrode system, showcasing a high specific capacitance of 2744 F/g at 4 A/g. The full supercapacitors based on Ni-Co-P-S as positive electrode and active carbon as negative electrode showcase a high specific capacitance of 110.9 F/g at 1 A/g, impressive energy density of 39.4 Wh/kg at a power density of 797.5 W/kg in terms of excellent cycling stability (91.87% retention after 10,000 cycles). This simple electrodeposition strategy for synthesizing Ni-Co-P-S can be extended to prepare electrode materials for various sustainable electrochemical energy storage/conversion technologies.

A smelting multiple recrystallization strategy and its effects on the morphology, composition, and defects of CsPbBrI2 film were investigated. An optimal number (n = 2) of recrystallization cycles improved the crystallinity and phase purity, minimized the grain boundaries, and optimized the crystal structure, yielding a high-quality perovskite film with significantly reduced defects density. The corresponding photovoltaic devices exhibited a champion efficiency of 16.02% under AM 1.5 G illumination and presented an even higher indoor efficiency of 33.50% under an LED (2956 K, Pin: 334.41 μW/cm2). This recrystallization method offers a promising strategy for developing high-performance indoor and outdoor photovoltaics. Direct recrystallization in the cells was also explored to achieve enhanced stability and longer lifetime in humid conditions.

There is a challenge to increase the application range of chalcogenide materials due to the fixed photoelectric properties and complex preparation process. To solves the problem, bulk ceramics with different doping ratios should be investigated. Here, the influence of the doping ratio of molybdenum MO and Ga oxide on the composition, structure, morphology and luminescence properties of bulk ceramics is studied, the optimal doping ratio in this range is determined by analysis of mass loss and volume shrinkage. The cubic crystal structure is confirmed by X-ray diffraction results. The results showed that molybdenum was successfully doped Mo into the matrix material is revealed by Raman spectroscopy. The X-ray fluorescence is used to study the composition ratio changes of bulk ceramics before and after sintering. The molecular structure model of Mo–ZnSe/ZnS with different concentration is constructed. The X-ray photoelectron spectroscopy shows the spin orbits of Zn 2p and S 2p, as well as the +3 valences in terms of Mo and Ga. The optical performance is enhanced the light-emitting band is enlarged to the near infrared region. All the work suggest that this new compound has an improved micro-structural, optical and electrical properties. This research can provide theoretical and experimental reference for the doping research of chalcogenide materials and new optoelectronic devices.

Food packaging with efficient antibacterial ability is highly desirable and challenging in facing the crisis of microbial contamination. However, most present packaging is based on metal-based antibacterial agents and requires a time-consuming antibacterial process. Here, the unique packaging (CC/BB films) featuring aggregation-induced emission behavior and photodynamic inactivation activity is prepared by dispersing self-assembled berberine-baicalin nanoparticles (BB NPs) into a mixed matrix of sodium carboxymethylcellulose-carrageenan (CC). The superiority of this design is that this packaging film can utilize sunlight to generate reactive oxygen species, thus eradicating more than 99% of E. coli and S. aureus within 60 min. Also, this film can release BB NPs to inactivate bacteria under all weather conditions. Surprisingly, the CC/BB nanocomposite film presented excellent mechanical performances (29.80 MPa and 38.65%), hydrophobicity (117.8°), and thermostability. The nanocomposite film is validated to be biocompatible and effective in protecting chicken samples, so this work will provide novel insights to explore safe and efficient antibacterial food packaging.

Microrobots have attracted considerable attention due to their extensive applications in microobject manipulation and targeted drug delivery. To realize more complex micro-/nanocargo manipulation (ie.g/i., encapsulation and release) in biological applications, it is highly desirable to endow microrobots with a shape-morphing adaptation to dynamic environments. Here, environmentally adaptive shape-morphing microrobots (SMMRs) have been developed by programmatically encoding different expansion rates in a pH-responsive hydrogel. Due to a combination with magnetic propulsion, a shape-morphing microcrab (SMMC) is able to perform targeted microparticle delivery, including gripping, transporting, and releasing by "opening-closing" of a claw. As a proof-of-concept demonstration, a shape-morphing microfish (SMMF) is designed to encapsulate a drug (doxorubicin (DOX)) by closing its mouth in phosphate-buffered saline (PBS, pH ∼ 7.4) and release the drug by opening its mouth in a slightly acidic solution (pHlt; 7). Furthermore, localized HeLa cell treatment in an artificial vascular network is realized by "opening-closing" of the SMMF mouth. With the continuous optimization of size, motion control, and imaging technology, these magnetic SMMRs will provide ideal platforms for complex microcargo operations and on-demand drug release.

In order to solve the transient heat transfer problem of the laminated structure, a semianalytical method based on calculus is adopted. First, the time domain is divided into tiny time segments; the analytical solution of transient heat transfer of laminated structures in the segments is derived by using the method of separation of variables. Then, the semianalytical solution of transient heat transfer in the whole time domain is obtained by circulation. The transient heat transfer of the three-layer structure is analyzed by the semianalytical solution. Three time-varying boundary conditions (a: square wave, b: triangular wave, and c: sinusoidal wave) are applied to the surface of the laminated structure. The influence of some key parameters on the temperature field of the laminated structure is analyzed. It is found that the surface temperature of the laminated structure increases fastest when heated by square wave, and the maximum temperature can reach at 377°C, the temperature rises the most slowly when heated by the triangular wave, and the maximum temperature is 347°C. The novelty of this work is that the analytical method is used to analyze the nonlinear heat transfer problem, which is different from the general numerical method, and this method can be applied to solve the heat transfer problem of general laminated structures.

In this study, a nitrogen-doped 3D porous starch-derived carbon/SnO2/carbon (PSC/SnO2/C) composite is synthesized with porous starch as a carbon source by biological enzymatic hydrolysis. Compared with the traditional complex acid-base reagent method, the biological enzymatic method is more environmentally friendly and economical, and it can also naturally introduce nitrogen sources and dope the carbon layer. Many mesoporous nanostructures provide enough buffer space and promote the ions' and electrons’ transmission rate. The formation of the Sn–O–C bond between SnO2 and carbon ensures the stability of the structure. As a result, the PSC/SnO2/C composite exhibits a high initial discharge capacity (1802 mAhg−1 at 0.2 A g−1 for LIBs and 549 mAh g−1 at 0.1 A g−1 for SIBs) and good cycle stability (701 mAh g−1 at 0.2 A g−1 after 100 cycles for LIBs and 271 mAh g−1 at 0.1 A g−1 after 100 cycles for SIBs). This synthesis method can prepare other energy storage systems such as fuel cells, supercapacitors, and metal ion batteries.