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In this paper, an enhanced thermal model is proposed for pouch batteries, which can be used for a battery management system (BMS) at low temperatures and high current rates. This thermal model integrates a virtual resistance model (VRM) and post resistance model at low temperatures. Firstly, based on the Arrhenius equation, the resistance model at low temperatures (from 0 °C to -10 °C) and high discharge rates (from 3.125C to 12.5C) is extrapolated from the resistance model under room temperature conditions. In this context, the resistance model at low temperatures is regarded as the VRM. In comparison to the experimental results, the maximum error of this VRM is 0.851 mΩ. Additionally, the equivalent post resistance model of the pouch battery, including that of the positive electrode and negative electrode, is also given for low temperatures. Finally, the complete thermal model for pouch batteries is validated at low temperatures and high discharge rates. The temperature evolution at different points on the battery, along with the heat generation properties of the battery, are simulated under cyclic pulse current and constant current working conditions. For cyclic pulse current, the maximum mean error in terms of temperature evolution is 0.72 °C, and for constant current working conditions, the maximum mean error is 0.79 °C.

Well-ordered hierarchically mesoporous/microporous carbon materials have been successfully fabricated by using dual soft-templating approach through compressed CO2. Pluronic F127 and different type of surfactants, including nonionic, cationic, and anionic surfactants, were used as dual templates to investigate the influence on the morphology and nanostructure of the as-prepared carbon samples. TEM, SEM, N2 sorption, wide-angle and small-angle XRD analysis were employed to reveal the well-ordered hierarchically micro-mesoporous structure with 2D hexagonal symmetry by using compressed CO2. The prepared HPC samples with different pressures as the catalyst carriers have been functioned by chlorosulfonic acid for the fructose conversion into HMF. Chlorosulfonic acid concentration, catalyst dosage and reaction temperature have been optimized for fructose-to-HMF transformation with the obtained catalyst. The performances of as-made HPC–SO3H samples in HMF yield and reaction rate of fructose-to-HMF transformation have been investigated. The stability of the samples was also conducted in the dehydration of fructose to HMF for five cycles. The possible catalytic mechanism by using hierarchically porous carbon materials as catalyst support for fructose-to-HMF transformation was proposed.

The as-solution-treated Sm2Co17-type magnets exhibiting a single 1:7H phase with different average grain sizes (D) are designed. Anisotropy of bending strength (Rbb) and compressive strength (Rmc) of the magnets was investigated. Moreover, the Rbb increases from 86 to 173 MPa with D decreasing from ∼52 to ∼18 μm for group c//h samples. The Hall-Petch correlation was employed to reveal the effect of grain size on mechanical properties of the magnets, giving deep understand the mechanical anisotropy characteristics. The relatively high Hall-Petch coefficient KRbb (0.79 MPa·m1/2) gives rise to the largest Rbb (173MPa) for group c//h samples. The mechanical anisotropy of the samples is well explained based on crystal structure and grain size features (grain boundaries). Grain refinement is an effective way to enhance the mechanical properties of Sm2Co17-type sintered magnets.

Hollow mesoporous metals have unique potential for catalysis, but their precise synthesis and further elaboration of their structure–performance relationships are still huge challenges. Herein, we ...

How to achieve uniform mixing of highly viscous fluids with low energy consumption is a major industry demand and one of the hot spots of mixing research. A typical multistage rotor-stator mixer (MRSM) equipped with a distributor was investigated to disclose the effects on the mixing performance and power consumption for highly viscous fluids via numerical simulation, considering the influence factors associated with different geometric parameters of both MRSM and the distributor. The mixing index and power consumption are used to evaluate the performance of the mixers. The dimensionless correlations for the mixing index and the power consumption are established considering the factors including the flow rate, rotor speed, the number of mixing units. Adopting the optimized mixer with the distributor (X1-T1), the mixing index increases to 0.85 (obviously higher than 0.46 for the mixer T1 without a distributor), meanwhile the corresponding power consumption is about 1/5 of that of T1 achieving the same mixing effect. It illustrates that the distributor can significantly improve the mixing of highly viscous fluids in the MRSM without the cost of large power consumption. These results would provide a guidance on the design and optimization of multistage rotor-stator mixers in industrial applications.

Cocrystallization integrates the merits of high energy and insensitivity between energetic molecules to obtain energetics with satisfying performance. However, how to obtain supramolecular synthons accurately and rapidly for predicting the structure and property of cocrystal remains a challenging problem. In this research, an efficient systematic search approach to predict CL-20/2,4-DNI cocrystal has been proposed that 2,4-DNI revolves around CL-20 with a stoichiometric ratio of 1:1 in accordance with the specified rules (hydrogen bond length: 2.2–3.0 A; search radius: 6.5 A; the number of hydrogen bond: 1–3). Eight possible supramolecular synthons were obtained by combining quantum chemistry with molecular mechanics. Crystal structure prediction indicated that there are four structures in cocrystal, namely P21/c, P212121, Pbca and Pna21, and CL-20/2,4-DNI cocrystal is likely to be P21/c and the corresponding cell parameters are Z = 4, a = 8.28 A, b = 12.17 A, c = 20.42 A, α = 90°, β = 96.94°, γ = 90°, and ρ = 1.9353 g/cm3. To further study the intermolecular interaction of CL-20/2,4-DNI cocrystal, a series of theoretical analyses were employed including intermolecular interaction energy, electrostatic potential (ESP), Density of State (DOS), Hirshfeld surface analysis. The C–H⋯O hydrogen bonds are demonstrated as the predominant driving forces in the cocrystal formation. The mechanical properties and detonation properties of CL-20/2,4-DNI cocrystal implies that the cocrystal shows better ductility and excellent detonation performances (9257 m/s, 39.27 GPa) and can serve as a promising energetic material. Cocrystal structure predicted was compared with the experimental one to verify the accuracy of systematic search approach. There is a less than 8.8% error between experiment and predict results, indicating the systematic search approach has extremely high reliability and accuracy. The systematic search approach can be a new strategy to search supramolecular synthons and identify structures effectively and does have the potential to promote the development of energetic cocrystal by theoretical design.

Inspired by the biosystems, the artificial smart membrane to control the mass transport and molecular conversion has attracted increasing attention in the fields of membrane separation, desalination, nanofiltration, healthcare and environmental remediation. However, the trade-off limitations in polymeric membranes greatly hinder the development of smart membranes with high permeability and manipulability. Recently, inspired by the unique physical/chemical properties of two-dimensional (2D) materials, 2D materials-based smart membranes (2DSMs) with the ability of intelligent regulation under different stimuli are highly suitable for membrane applications. According to the desired properties, the 2DSMs with abundant functional groups can be designed through chemical modification to change the original properties and obtain tunable interlayer spacings under different external conditions. In this review, we summarize the recent progress on artificial smart membranes based on 2D materials. The design concept and fabrication strategy of 2DSMs are first introduced. Following that, the developed 2DSMs are introduced and classified by the type of responsive stimuli, including pH, magnetic field, electric field, light and temperature. Then, the 2DSMs exhibiting unique performances as membrane separation, pressure sensors, blue energy harvesting, photoelectrochemical sensors and biomimetic devices are presented. Finally, the perspectives and challenges in the developments of 2DSMs are discussed

A TD-tilted basal texture in Mg alloys often generates a strong planar mechanical anisotropy. Unfortunately, there has been not a quantitative study on this issue. In the present study, the mechanisms for the anisotropy of tensile yield strength in RD-TD plane were quantitatively studied for a Mg-2Zn-1Ca alloy with different grain sizes and textures. Here, RD and TD refer to the rolling direction and transverse direction of the plate. The results show that there is a strong planar yield anisotropy (∼ 24 ± 5 MPa), regardless of grain size, while this yield anisotropy is absent in texture with a circular distribution of basal poles. The examination of microstructure and X-ray diffraction analysis reveals that, besides basal slip as the predominant mode under both RD-tension and TD-tension, prismatic slip in RD-tension and both prismatic slip and extension twinning in TD-tension are also important. The parameters of Hall-Petch relation are also used to further analyze the mechanism for yield anisotropy. The changeable intercept, σ 0 , and invariant Hall-Petch slope, k, between RD-tension and TD-tension are rationalized accounting for this anisotropy. The reasons why there are different σ 0 and similar k between TD-tension and RD-tension are quantitively discussed. At last, a texture design for decreasing the planar yield anisotropy is given.

Droplet-based microfluidic technology can be utilized as a microreactor to prepare novel functional monodisperse microcapsules. In this study, a droplet-based microfluidic chip with surface modification, which allowed the one-step preparation of double emulsion microcapsules. An O/W/O double emulsion using polyethylene (glycol) diacrylate (PEGDA) solution as the intermediate water phase was prepared by regulating the hydrophilicity and hydrophobicity of the chip surface, with PEGDA microcapsules prepared using UV polymerization. And then anti-tumor drug paclitaxel and neurotoxin 6-OHDA were encapsulated in microcapsules for drug and toxicology evaluation, respectively. Compared to controls, drug-loaded microcapsules caused a significant increase in the death rate of PC12 cells. This indicates that the obtained drug-loaded microcapsules could be used in drug evaluation and potentially in drug screening and delivery.

The new near-α TNW700 titanium alloy is a potential candidate material for high performance ultrasonic/hypersonic aircrafts, which is designed for short-term service at 700°C. This study systematically investigated the superplastic deformation microstructure evolution and mechanism of TNW700 alloy at different strain rates and true strains at 925°C. Results show that TNW700 alloy exhibits excellent superplastic behavior in a constant strain rate range of 0.0005 to 0.005 s−1 with elongation above 400%. The peak stress decreases with decreasing strain rate, which is related to the increase of β-phase volume fraction caused by the increase of thermal exposure time. In addition, significant strain hardening is observed in early-middle stage of superplastic deformation, and flow softening is followed in middle-late stage. To rationalize these complex flow behaviors, electron backscatter diffraction (EBSD) and high resolution transmission electron microscopy (HRTEM) were used to characterize the microstructure. Strain hardening is correlated to the synergistic effect of β grain growth, dislocation accumulation, silicide precipitate, and solid solution strengthening of α phase. Continuous dynamic recrystallization (CDRX) induced the fragmentation of primary α grains in middle-late stage of superplastic deformation, and the refinement of α grains, the increase of β phase volume fraction and dynamic dislocation recovery are main causes of high strain softening. In addition, EBSD and TEM observations confirmed texture randomization, fine equiaxed primary α grains and intragranular dislocation movement, indicating that grain boundary sliding (GBS) accommodated by dislocation sliding / climb is the dominant superplastic deformation mechanism of TNW700 alloy.

In the present study, we have prepared glutathione capped gold and platinum alloy nanoclusters (Au-PtNCs) in a controlled way by employing the hydrothermal method and optimized through adjusting the ratio of raw materials, reaction temperature, and time. Compared with the corresponding monometallic gold and platinum nanoclusters, the alloy nanoclusters' catalytic activity is improved dramatically in the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) in the presence of H2O2. And the maximum velocity is calculated to be 106 × 10−8 M∙s−1 for TMB as substrate, being much better than that of other reported metallic nanoclusters and nanoparticles. Further study shows that the high catalytic activity mainly attributes to the synergistic effect of gold and platinum. Besides, they have been applied to determine H2O2 in the presence of TMB, which shows high sensitivity with a limit of detection (LOD) at 100 nM. The proposed method has been used to determine H2O2 in milk and contact lens solutions, which shows very good recovery and exhibits high practical application potential. Therefore, the present study provides a new type of alloy nanoclusters with high peroxidase-like activity, which will inspire more research interests on doping and alloying with Pt to improve the catalytic activity of metal nanoclusters.

High oxygen concentration oxy-fuel circulating fluidized bed (CFB) combustion technology is a high efficiency and low cost oxy-fuel combustion technology, which also has high potential of optimization and efficiency improvement. In this research, energy efficiency is analysed to acquire the effects of flue gas recirculation mode, preheating temperature and oxygen purity on the net efficiency and energy consumption of the 50% oxy-fuel combustion system, so as to obtain the further optimization strategy. The following results are obtained by simulation. The optimal extraction position of recycled flue gas (RFG) is gas preheater outlet, and the net power generation efficiency increases by 0.23% to 25.08%. As the preheating temperature increases from 230 to 400 °C, the net efficiency increases by 1.19% to 26.04%. The net efficiency increases first then decreases as the oxygen purity at ASU outlet increase from 89% to 97.4%, and the optimal value is the 94%. Finally, the optimal system is obtained when RFG is extracted from gas preheater outlet, the preheating temperature is 400 °C and the oxygen purity at ASU outlet is 94%. The net efficiency of the optimization system reaches 27.4%, increasing by 2.55%.

Structure, magnetic properties and ductile of melt-spun Fe83-xSi4B13-yCyCux (x = 0–1.7; y = 0–8) alloys were investigated. The addition of 1.7 at.% Cu in a Fe83Si4B13 amorphous alloy generates abundant α-Fe crystals by providing nucleation sites, and further C doping promotes the growth of the crystals by suitable turning amorphous-forming ability, hence they increase saturation magnetic flux density (Bs) and slightly worse magnetic softness of the as-spun alloys. The as-spun Fe81.3Si4B7C6Cu1.7 alloy possesses a combined structure of a fully amorphous layer in wheel side surface and predominating nanocrystalline structure with gradually enlarged α-Fe crystal, whose average size and volume fraction are determined as about 12 nm and 32%, respectively, therefore superior soft magnetic properties and ductile with a high Bs of 1.74 T, coercivity (Hc) of 32.7 A/m, effective permeability (μe, at 1 kHz) of 3200 and high relatively strain at fracture (ef) of 3.61% can be achieved directly in this alloy by only using melt-spinning. The annealing at 578 K releases internal stress, promotes the growth of the α-Fe crystals and remains the amorphous layer of the Fe81.3Si4B7C6Cu1.7 alloy, then improves the soft magnetic properties and maintains the superior ductile with increasing the Bs and μe to 1.80 T and 14,100, respectively, lowering the Hc to 9.4 A/m and slightly reducing the ef to 2.39%. The combination of superior soft magnetic properties and ductile and simplified synthesis process entitles the Fe-Si-B-C Cu nanocrystalline alloys great potentials in high performance electromagnetic applications.

Photocatalytic technology can solve various environmental pollution problems, especially antibiotic pollution. A novel La-doped MIL-53(Al)/ZnO composite material was successfully synthesized by a combination of hydrothermal method and calcination, showing high photocatalytic degradation percent of sulfamethazine (SMT). The 2 mol% La MIL-53(Al)/ZnO photocatalyst shows the highest degradation efficiency toward SMT (92%) within 120 min, which is 4.1 times higher than pure ZnO (increased from 18% to 92%). In addition, the degradation analysis of SMT by high performance liquid chromatography proves that the products are CO2 and H2O. The improved photocatalytic activity is mostly caused by the following factors. (1) Doping La ions can decrease the band gap of ZnO, enhance light response, and effectively enhance the separation rate of photo-generated holes and electrons. (2) MIL-53(Al) can adsorb SMT and promote the separation of electron. This work shows that the synthesized La-doped MIL-53(Al)/ZnO photocatalyst is expected to be used as a green and effective method for treatment of environment water pollution.

Silicon (Si) is an ideal anode material for lithium ion batteries (LIBs) because of its high gravimetric capacity (3579 mAh g−1). However, Si anode undergoes sharp volume expansion during the charge/discharge process and then easily fragments to forfeit electronic contact, thereby forming dead Si, especially for micron-sized Si particles. We prepared a free-standing Si-based film anode, in which the micron Si particles are embedded by a coupled network of carbon nanotubes and the micro-nano structure is anchored by a carbon nanocoating layer. The networks can catch the nanominiaturized Si particles and provide continuous electrical contact during long cycling, thereby reviving the fragmented Si and maintaining lithium storage properties. This Si anode exhibits an ultra-high specific capacity of 3385.2 mAh g−1. The excellent cycling performance of 2345.3 mAh g−1 remained after 100 cycles at a current density of 0.3 A g−1. The pouch LIB based on the Si anode showed outstanding rate capacity and flexibility. This strategy is expected to solve the volume expansion and promote the application of the micron Si-based materials.

Electrochemically deposited sensors and DNA biosensors have been widely used in the food industry, and various other fields due to their high sensitivity, fast response, easy operation, no pollution, and low price. A rare earth electrochemically deposited gadolinium ferricyanide thin film modified glassy carbon electrode, and the investigation of electrocatalytic oxidation of guanine by GaHCF/GCE is reported. We deposited electrochemically a rare earth terbium ferricyanide thin film modified glassy carbon electrode. OH was investigated through various characteristics such as capacitance–voltage, Differential Pulse Voltammetric and many more by the comparison of catalytic oxidation signal of guanine with ·OH in Fenton reaction.

Room-temperature thermoelectric materials provide promising solutions for energy harvesting from the environment, and deliver a maintenance-free power supply for the internet-of-things (IoTs). The currently available Bi2Te3 family discovered in the 1950s, still dominates industrial applications, however, it has serious disadvantages of brittleness and the resource shortage of tellurium (1 × 10−3 ppm in the earth's crust). The novel Mg3Sb2 family has received increasing attention as a promising alternative for room-temperature thermoelectric materials. In this review, the development timeline and fabrication strategies of the Mg3Sb2 family are depicted. Moreover, an insightful comparison between the crystallinity and band structures of Mg3Sb2 and Bi2Te3 is drawn. An outlook is presented to discuss challenges and new paradigms in designing room-temperature thermoelectric materials.

Aluminum-based composite abradable seal coatings are pivotal to improving the efficiency of aero engines or gas turbines. However, the adhesive transfer frequently occurs between metallic blade tips and aluminum-based composite coatings, resulting in engine vibration and even jam. Many past studies had tried to solve this problem by reducing coating hardness, improving lubrication, or strengthening blade tips, but all had failed. In this paper, we proposed a novel epoxy-based composite abradable seal coating, eliminating adhesive transfer by changing metal-to-metal scraping pair to metal-to-polymer scraping pair. The coating was developed via a hierarchical structure design. Large spherical pores were uniformly distributed in the continuous epoxy matrix with fine graphite dispersion. By adding 20 vol.% graphite and 50 vol.% hollow microspheres, a self-lubricating epoxy-based coating of 0.26 friction coefficient with thermal conductivity of 0.28 W/(m·K), coating HR15Y hardness at 54.8, and bonding strength at 18.7 MPa can be reached. When the metallic blades scrape the epoxy-based composite coating, no adhesive transfer occurs. Besides, a smooth scraped surface is formed by pseudoplastic deformation. This epoxy-based composite abradable seal coating opens a new way to improve the efficiency and reliable operations of air engine compressors.

The present work studies the dynamic stability of a parametric amplification model of a vibrating beam micro-gyroscope with consideration of the size-dependent effect and the fringing field effect. Four piezoelectric layers are bonded to the surfaces of the cantilever beam, which are additional components compared with conventional micro-gyroscopes. The cantilever beam will be subjected to steady and time varying axial excitations due to the application of the DC and AC voltages piezoelectric actuation. The axial excitation may provide parametric amplification to enlarge the transverse vibrations and enhance the sensitivity of the micro-gyroscope. The stability of the gyroscopic system is determined by using Floquet theory, and the stability boundaries are obtained by harmonic balance method. The effect of the damping, size-dependent, fringing field, tip mass, electrostatic and piezoelectric DC voltages on the dynamic stability of the vibrating beam micro-gyroscope is investigated. As studying the stability in most literatures, they always discussed non-gyroscopic system while this paper considering the gyroscopic system is relatively new. We also investigate the waveform and phase diagrams of arbitrary points inside and outside the stability boundaries based on the numerical calculation, these results are to verify the correctness obtained by harmonic balance method. Finally, the effect of angular speeds on the stability analysis of the gyroscopic system is studied for the first time.

Piezophotonics is a great interesting field of physics that has led to a number of important technologies, such as light source, smart sensors, and mechatronics. In this work, we reported Pr-doped (Bi0·5Na0.5)TiO3-based lead-free ceramics with strong red photoluminescence emission and large strain response (d33∗ = 460 pm/V, S = 0.32 %). The PL emission can be quenched by decreasing the intensity by 93 % after electrical polarization (E = 50 kV/cm). The local structure and electric field-induced structural changes were systematically investigated to reveal the significant distinction in photoluminescence properties caused by electrical polarization. The results indicated that polarization treatment eliminates the structural inhomogeneities and establishes a long-range ferroelectric tetragonal and rhombohedral distortion. The crystal structure transformed irreversibly from a non-ergodic to a normal ferroelectric state. PL quenching originated from the decreased distortion of octahedral due to the transition from a non-ergodic state to a highly ordered symmetrical structure. Meanwhile, the enlarged domain structure contributed to the photoluminescence quenching effect. Our findings demonstrate that an electric field can be a robust tool for adjusting the photoluminescence property and provide insights into the relationship between the structure and PL properties of BNT-based ceramics under an external stimulus.

Thermal barrier coating (TBC) materials perform an increasingly important role in the thermal or chemical protection of hot components in a gas turbine. In this study, a novel high entropy hafnate (Y0.2Gd0.2Dy0.2Er0.2Yb0.2)2Hf2O7 was synthesized by solution combustion method and investigated as a potential TBC layer. The as-synthesized (Y0.2Gd0.2Dy0.2Er0.2Yb0.2)2Hf2O7 possesses a pure single disordered fluorite phase with a highly homogeneous distribution of rare earth (RE) cations, exhibiting prominent phase stability and excellent chemical compatibility with Al2O3 even at 1300 °C. Moreover, (Y0.2Gd0.2Dy0.2Er0.2Yb0.2)2Hf2O7 demonstrates a more sluggish grain growth rate than Y2Hf2O7. The thermal conductivity of (Y0.2Gd0.2Dy0.2Er0.2Yb0.2)2Hf2O7 (0.73-0.93 W m−1 K−1) is smaller than those of components RE2Hf2O7 and many high entropy TBC materials. Beside, the calculated thermal expansion coefficient (TEC) of (Y0.2Gd0.2Dy0.2Er0.2Yb0.2)2Hf2O7 (10.68 × 10−6/K, 1100 °C) is smaller than that of yttria-stabilized zirconia (YSZ). Based on the results of this work, (Y0.2Gd0.2Dy0.2Er0.2Yb0.2)2Hf2O7 is suitable for the next generation TBC materials with outstanding properties.

Electromagnetic wave (EMW) absorbing materials have excellent potential for various applications in civil engineering and the military. In this study, siliconboron carbonitride (SiBCN) ceramics with excellent EMW absorption capability and oxidation resistance were obtained by adjusting the boron content. The results revealed that the graphite crystallite size in the SiBCN ceramics increased from 3.42 to 3.78 nm, whereas the thickness of the oxide layer decreased from 16.6 to 8.2 μm. The highest electrical conductivity and permittivity for the SiBCN ceramics were obtained when the boron content was 5%. The minimum reflection loss was −35.25 dB at 10.57 GHz and a ceramic thickness of 2.0 mm. At a temperature of 600 °C, the SiBCN ceramic exhibited excellent EMW attenuation ability; particularly, the minimum reflection loss reached −29.18 dB at 9.65 GHz and a ceramic thickness of 2.5 mm. The superior EMW absorption properties of the SiBCN ceramics at high temperatures can be ascribed to the synergistic effect of relaxation and conductivity. The results suggest that boron could enhance the transformation of amorphous carbon into crystalline graphite and increase the number of heterointerfaces and conductive paths. This work provides a method for obtaining SiBCN ceramics with excellent EMW absorption properties.

Despite the continuously increased requirement on automated synthesis of medicines for distributed manufacturing and personal care, it remains a challenge to realize automated synthesis which requires solid-liquid phase reactions. In this work, we demonstrated an automated solid-liquid synthesis for gadopentetate dimeglumine, the most widely used magnetic resonance imaging (MRI) contrast agent. The high-efficiency reaction was performed in a 3D microfluidic chip which was fabricated by femtosecond laser micromachining. The structure of the chip realized 3D shear flow which was essential for highly efficient mixing and movement of the solid-liquid mixtures. Ultraviolet visible (UV–vis) spectrometer was employed for in-line analysis to help automation of this system. Comparing with the round-bottom flask system, this synthetic system showed significantly higher reaction rate, indicating the advantage of the 3D microfluidic technology in micro chemical engineering.

A special structure named tetrahedral twin was found in a cold-drawn CoCrFeNi high-entropy alloy. Crystallographic characterization using convergent beam electron diffraction indicated that the three-dimensional (3D) tetrahedral twins were achieved through the intersection of each couple of twin layers in four {111}FCC planes, which was caused by the low stacking fault energy and the special plane strain state during deformation. The calculation results revealed that the tetrahedron-morphological twins could result in significant stress concentration, thereby considerably deteriorating the plasticity of the high-entropy alloy.

Yttria-stabilized zirconia coatings were prepared by atmospheric plasma spraying, and the bonding strength of the coatings was determined by tensile testing. The microstructure of the coating, including grains and pores, was characterized using scanning electron microscopy and electron backscatter diffraction. The results show that the higher the proportion of columnar grains, the higher the bonding strength. The large misorientation at the small grains leads to large stress, which is easy to fracture in the tensile process, so the existence of small grains leads to poor bonding strength. By using image processing, pores were classified as holes, cracks, and microcracks, and their proportions were calculated. It was found that both holes and transverse and vertical cracks in pores linearly affected the bonding strength; the influence of holes was the greatest, and the influence of microcracks was the smallest. In conclusion, the smaller the porosity, the greater the bonding strength of the coating.

A one-step hydrothermal treatment was used to deposit a nano silver-loaded magnesium-aluminum hydrotalcite (Ag/Mg-Al) layered double hydroxide (LDH) coating onto the surface of a Mg-Zn-Ca alloy to improve the corrosion resistance and antibacterial properties of magnesium alloys for biomedical applications. The effect of experimental parameters such as temperature and time on the microstructure, compositions, and corrosion resistance of the Ag/LDH coating during the hydrothermal treatment was investigated to optimize the preparation process. Additionally, the in vitro degradation performance, antibacterial performance and biocompatibility of the coating were evaluated to determine the optimal preparation condition. The results show that when the LDH–NO3– coating is prepared at 110 °C for 10 h, the constituting silver particles (dimensions, 10–30 nm) are obtained, while the corrosion current density and the corrosion rate decrease to 4.41 μA/cm2 and 0.27 mm/year, respectively. The antibacterial experiment demonstrates that the coating effectively inhibits the reproduction of Escherichia coli while offering remarkable biocompatibility.

An accurate estimation for the magnetostrictive effect in highly grain-oriented electrical steel sheet (HGO-ESS) is helpful for determining the deformation and vibration originating from magnetostriction during the design stages of electrical equipment such as the motor and power transformer. In this paper, a Preisach-based magnetostriction model for HGO-ESS is proposed to simulate the normal and shear magnetostriction properties under alternating and rotating magnetic fields. In the model, the Everett function databases are constructed and identified by using a set of measured symmetric magnetostriction butterfly loops under different rotating magnetic field conditions. The measurement butterfly loops are measured by a round-type two-dimensional single strain tester (R-2-D-SST). Finally, the simulation data and measurement data under different rotational magnetization conditions are compared to verify the effectiveness of the proposed model.

Sodium salts of mono- and di- carboxylic acids (glycolic, fumaric and benzoic acid) were studied as corrosion inhibitors for AM50 alloy in pH neutral aqueous NaCl environment. Hydrogen evolution, electrochemical and surface characterization techniques were employed to reveal their corrosion inhibition mechanism, whilst the molecular features of inhibitors were investigated by quantum chemical calculation. All inhibitors reduced anodic dissolution of AM50 and their efficiency generally increased with time and concentration from 5 mM to 100 mM. The inhibition mechanism can be described as physisorption of inhibitive molecules on the surface of the intrinsic oxide layer followed by chemisorption with Mg2+ and Al3+, and the difference in inhibition action among these inhibitors was explained on the molecular scale.

Ta-doped Bi3.25La0.75Ti3O12(BLTT)/ZnO films were fabricated on Pt(111)/Ti/SiO2/Si substrates by a magnetron sputtering method. Firstly, ZnO crystal thin films were grown on the substrates by a reactive sputtering method. Then, BLTT thin films were deposited on the ZnO layers at room temperature and post-annealed at 600 °C. The micromorphology, ferroelectric and dielectric properties of BLTT/ZnO films were analyzed. The XRD analysis shows that ZnO buffer layer significantly reduces the crystallization temperature of BLTT thin film. The TEM results show that lamellar BLTT grains are grown on ZnO layer at a certain angle with few elements diffusion at the interface of ZnO phase and Bi4Ti3O12 phase. The ferroelectric properties indicate that BLTT/ZnO films exhibit different remanent polarization and coercive fields under electric field with different directions. The novel mechanism of tailoring ferroelectric properties may open new possibilities for designing special ferroelectric devices.

The macromolecular architecture is the crucial factor in determining the arrangement of the ordering structures, which because of the multiscale feature may exhibit distinct melting behaviors and induces the so-called memory effect to affect the following recrystallization. Until present, the correlation between the occurrence of memory effect and the intrinsic molecular structure is still far from the comprehensive understanding. In this work, four kinds of 1-butene/α-olefin random copolymers were designed and synthesized using the (pyridyl-amino) hafnium catalyst to introduce the different branches. The branch length was precisely controlled by the specific α-olefin comonomers, which include 1-hexene, 1-decene, 1-tetradecene, and 1-octadecene, while the branch density was tuned by the incorporation. As expected, the incorporation of α-olefin co-units to poly(1-butene) backbone decreases the non-isothermal crystallization kinetics and the degree of crystallinity. More interestingly, the resulting linear branch is able to induce the occurrence of memory effect and the threshold concentration of co-units (i.e., branch density) decreases with increasing the branch length. Based on the results of these 1-butene/α-olefin copolymers with designable branches, a direct correlation with the occurrence of memory effect and the fraction of amorphous region was established, which quantitatively indicates the degree of local segregation of the crystallized poly(1-butene) sequences by the α-olefin co-units.

Resistive random-access memory (RRAM) is a promising technology to develop nonvolatile memory and artificial synaptic devices for brain-inspired neuromorphic computing. Here, we have developed a STO:Ag/SiO2 bilayer based memristor that has exhibited a filamentary resistive switching with stable endurance and long-term data retention ability. The memristor also exhibits a tunable resistance modulation under positive and negative pulse trains, which could fully mimic the potentiation and depression behavior like a bio-synapse. Several synaptic plasticity functions, including long-term potentiation (LTP) and long-term depression (LTD), paired-pulsed facilitation (PPF), spike-rate-dependent-plasticity (SRDP), and post-tetanic potentiation (PTP), are faithfully implemented with the fabricated memristor. Moreover, to demonstrate the feasibility of our memristor synapse for neuromorphic applications, spike-time-dependent plasticity (STDP) is also investigated. Based on conductive atomic force microscopy observations and electrical transport model analyses, it can be concluded that it is the controlled formation and rupture of Ag filaments that are responsible for the resistive switching while exhibiting a switching ratio of ~103 along with a good endurance and stability suitable for nonvolatile memory applications. Before fully electroforming, the gradual conductance modulation of Ag/STO:Ag/SiO2/p++-Si memristor can be realized, and the working mechanism could be explained by the succeeding growth and contraction of Ag filaments promoted by a redox reaction. This newly fabricated memristor may enable the development of nonvolatile memory and realize controllable resistance/weight modulation when applied as an artificial synapse for neuromorphic computing.

Large battery packs are used in electric vehicles. Heat is generated when the battery pack is being used. Therefore, it is necessary to predict battery heat generation. An enhanced electro-thermal model is developed to describe the temperature distribution inside a battery pack. It combines the dynamic resistance model and the current distribution model. The resistance model is affected by the thermal and electrical parameters, while the current distribution model considers the interaction between cell status and current variation in the parallel branch. The proposed model can accurately predict the temperature change of cells in the pack under static and dynamic current conditions. Experiments are conducted to validate the prediction accuracy. Most of the average absolute errors (AEave) between the predicted value and test value displayed on the experimental device do not exceed 0.4 °C under static current conditions, and all of them are below 0.1 °C under dynamic current conditions. The two existing models, namely the state-of-charge (SOC)-dependent resistance model [R(SOC)] and SOC-T-dependent resistance model [R(SOC, T)], have AEave values of 1.6 and 0.54 °C when the pack is discharged at 0.5 C. In contrast, the AEave value achieved by our proposed model is 0.4 °C. Under dynamic current conditions, the maximum AEave s are 0.42 °C for the R(SOC) model, 0.26 °C for the R(SOC, T) model, and 0.16 °C for the proposed model. These results demonstrate that the proposed model provides more accurate predictions of the temperature rise inside the pack than the popular existing models.

Synergistically tuned noble metals and intentionally formed complex heterostructured nanomaterials can enhance the required application effectiveness but at the cost of tedious synthesis routes, expensive chemicals, and sophisticated instruments. To overcome such demerits, herein, we report on the oleic acid-mediated convenient co-precipitation route using water–hexane as a biphasic solvent for CuO synthesis in the form of nano feathers (CuO-NF), solid/hollow hexagonal thin sheets (CuO-HS), and mega sheets (CuO-MS) at room temperature. The exotic CuO nanoarchitectures achieved were tested and compared with control samples (CuO-IS) for CO2 sensing, natural sunlight induced dye degradation, and catalytic CO2 reduction. Among the various CuO nanostructures synthesized, CuO-HS depicted higher oxygen deficiency, electronic conductivity, and visible light absorption. Most of the solid/hollow hexagonal thin sheets depicted an edge length in the 50–350 nm range with an observed thickness as low as 5 nm. The CuO-HS microsensor demonstrated ultrasensitivity (Rg/Ra = ∼85), dominant selectivity (>6 gases), repeatability (98.7%), CoV (1.3%), and LoD (4.3 ppm) at 32 °C towards CO2 in 20–5000 ppm. The role of structural defects in sensing was confirmed from operando UV-Vis-DRS & PL. Rapid dye degradation in natural sunlight shown by CuO-HS was primarily attributed to the lower charge reunification. Additionally, CuO-HS facilitated methanol formation within 3 h at a rate of 53 and 18 μmol g−1 in the presence of artificial solar and natural sunlight, respectively. Dye degradation and CO2 photoreduction pathways were probed using HPLC and GC-MS, respectively.

Nitrogen doping can improve the electrocatalysis performance of hard carbon (HC) as a promising anode material in sodium-ion batteries, but is very challenging to controllably decrease the content of low-active graphitic-N in C–N configurations for raising the HC anode performance. Here an iodine-predoping approach is used to effectively restrain graphitic-N formation and its mechanism is further revealed, in which iodine preferentially occupies the vacancy sites of graphitic-type carbon to directionally induce nitrogenous species bonding with the vacancy sites of pyridinic- and pyrrolic-type. Experimental characterizations and theoretical calculations solidly confirm the mechanism. As expected, the controllably constructed HC anode exhibits the highest reversible capacity of 483.1 mAh g−1 at 30 mA g−1 among all reported HC works, while delivering a long lifespan up to 6000 cycles decaying only 0.0096% per cycle at 1 A g−1. This work sheds light on viable fundamentals for controllably constructing desired C–N configuration for host materials.

Although solar energy is promising for water purification, there is still a room for further improving the solar steam generation efficiency. Herein, an environmental energy-enhanced solar steam evaporator is fabricated by immersing a cellulose acetate fiber-based cigarette filter (CF) in an aqueous solution of polyvinyl alcohol (PVA) followed by freeze-drying and decorating with MXene sheets. The presence of MXene is to absorb solar light and convert solar energy to thermal energy for efficient water evaporation, while the porous PVA network generated inside the pores of the filter during the freeze-drying process accommodates the dispersed MXene sheets and interconnects the CF and MXene. Because of the constructed PVA/MXene network inside the CF porous architecture and the hydrophilic feature of both MXene and PVA, the resultant MXene/PVA modified CF (MPCF) is highly hydrophilic and competent for rapid upward transfer of water. Interestingly, in addition to the normal energy input by the incident solar light, the large-area sidewall of MPCF gains thermal energy from the environment in the forms of heat convection and heat radiation to enhance the solar steam generation efficiency, resulting in an ultrahigh water evaporation rate of 3.38 kg m−2 h−1 with an outstanding evaporation efficiency of 132.9%.

Mineralization of the ZIF-8 in the presence of biomacromolecules has been demonstrated to be a general way for making bioentities@ZIFs composites. The ZIF-8 crystals permit controlled storage and utilization of the bioentities, thus can benefit drug delivery, cold-chain breaking etc. With the increasing needs on personal care and distributed manufacturing, automated synthesis controlled by a computer becomes the next challenge. In this work, we designed an automatic synthesis system to prepare PEG mineralized ZIF-8 composite particles. This system is based on flow chemistry with the microfluidic chips fabricated by femtosecond laser micromachining. The particles were synthesized and monitored automatically. Furthermore, this synthesizer could be extended for fabrication of vaccine particles under remote control through internet.

Nickel hydroxide, as a high high-efficiency electroactive material, is a promising electroactive material for advanced hybrid supercapacitors due to its high theoretical capacity, low-cost, and good thermal and chemical stabilities. Although various nanostructures of nickel hydroxide have been widely reported for energy storage devices, such as nanoparticles, nanosheets, nanoflowers, and so on, nickel hydroxide with one-dimensional nanowire morphology has been rarely investigated until now. Meanwhile, previous reports have shown that the energy storage performance of α-Ni(OH)2 is superior to other types of nickel hydroxides. Based on the above points of view, α type Ni(OH)2 nanowires with three-dimensional (3D) reticulation containing SO42− (abbreviated as NSOH NWs) were successfully obtained by a sulfate assisted hydrothermal approach in the present work and further employed as an electroactive material in hybrid supercapacitors (HSCs). The formation mechanism of the NSOH and the effects of SO42− are also discussed. Thanks to its novel 3D porous morphology and α-type phase structure, the as-prepared NSOH NW electrode presents a high specific capacity of 246.3 mA h g−1 at 1 A g−1, along with a good cycling stability of 91.7% after 4000 cycles. Meanwhile, the as-assembled NSOH NWs//AC HSCs can provide a high energy density of 59.8 W h kg−1 at a power density of 830.3 W kg−1. The HSCs also show 91.5% specific capacity retention after 10 000 cycles. All above results manifest that the proposed NSOH NWs with 3D reticulation have significant potential for advanced HSC applications.

Hydrogen evolution from electrochemical water splitting under alkaline conditions is an ongoing challenge for the requirement of a simultaneous balance to be achieved between the water dissociation step and the hydrogen adsorption on the catalysts. Herein, Bi2O3, an inactive catalyst for hydrogen evolution reaction (HER) aroused by its unfavourable hydrogen adsorption Gibbs free energy (ΔGH*), is activated by an in-situ phase engineering strategy for efficient HER electrocatalysis in alkaline media. Via this strategy, two-dimensional (2D) dual active Bi2O3 nanosheets with both BixNi alloy phases and α-Bi2O3 were fabricated to simultaneously catalyse the water dissociation step and the hydrogen formation step during the alkaline HER. In combining with the advantages of 2D nanomaterials and dual active catalytic sites, this phase engineered Bi2O3-based catalyst exhibited simultaneously accelerated water dissociation and optimized ΔGH* and thus excellent HER performance. The modulated catalyst demonstrated an overpotential of 127 mV (at j = 10 mA cm-2) and a Tafel slope of 92 mV dec-1 in 1 M KOH, which is exceptional compared with other Bi2O3-based HER electrocatalysts. This work not only provides an innovative way to activate HER-inferior bismuth oxide-based catalysts, but also offers new insights into the design of dual active catalysts for sluggish alkaline HER catalysis.

Computational screening of 231 adsorbent/water working pairs from experimental water adsorption isotherm database for AHPs is carried out based on effective coefficient of performance and effective temperature lift under practical working condition.

Power chips with high power dissipation and high heat flux have caused serious thermal management problems. Traditional indirect cooling technologies could not satisfy the increasing heat dissipation requirements. The embedded cooling directly inside the chip is the hot spot of the current research, which bears greater cooling potential comparatively, due to the shortened heat transfer path and decreased thermal resistance. In this study, the thermal behaviors of the power chips were demonstrated using a thermal test chip (TTC), which was etched with microchannels on its substrate’s backside and bonded with a manifold which also fabricated with silicon wafer. The chip has normal thermal test function and embedded cooling function at the same time, and its size is 7 × 7 × 1.125 mm3. This paper mainly discussed the influence of width of microchannels and the number of manifold channels on the thermal and hydraulic performance of the embedded cooling structure in the single-phase regime. Compared with the conventional straight microchannel structure, the cooling coefficient of performance (COP) of the 8×-50(number of manifold distribution channels: 8, microchannel width: 50 μm)structure is 3.38 times higher. It’s verified that the 8×-50 structure is capable of removing power dissipation of 300 W (heat flux: 1200 W/cm2) at a maximum junction temperature of 69.6 ℃ with pressure drop of less than90.8 kPa. This study is beneficial to promote the embedded cooling research, which could enable the further release of the power chips performance limited by the dissipated heat.

Supercapacitors with excellent electrochemical performance are considered the most promising candidates to meet the increasing energy demand. Herein, we developed a novel electrode material for supercapacitors, polyaniline (PANI)-3-aminopropyl triethoxysilane (APTEs)-titania nanowires (TNW), which was synthesized on potassium doped titanium foil via a simple two-step procedure. In the composite, the nano-mesh structure formed by APTEs-coated TNW serves as the framework for the growth of PANI nanoparticles, and PANI nanoparticles act as the electrochemically active part. The specific capacitance of PANI-APTEs-TNW of up to 315.16 mF cm−2 at 0.2 mA cm−2 in 1.0 M H2SO4 solution is achieved, while that of PANI-TNW is 271.67 mF cm−2. Meanwhile, the capacitance retention rate of PANI-APTEs-TNW is 86.8% after 1000 cycles under 1.5 mA cm−2. Compared to PANI-TNW, the better capacitive behavior of PANI-APTEs-TNW is attributed to the anchoring effect of APTEs, which is highly interactive and exhibits compact structures between the TNW and PANI nanoparticles, resulting in a stable structure during the rapid charge-discharge process. This strategy is characterized by its good electrochemical properties, simple equipment, low cost of raw materials, and large-area preparation. Thus, our findings provide an effective method for the design of high-performance supercapacitors and promote their practical applications.

The scarcity of two-dimensional (2D) magnetic nanostructures has hindered their applications in spintronics, which is attributed to that most magnetic materials exhibit non-van der Waals (nvdWs) structure and it is hard to reduce their thickness to 2D nanostructures. Thus it is eager to develop a promising strategy for free-standing 2D magnetic nvdWs nanostructures. We have achieved free-standing 2D nvdWs hexagonal FeSe with a thickness of 2.9 nm by the reaction between oleylamine-Se complex and Fe2+ with the assistance of Cl-, where the synergetic effects of Cl- and -NH2 lead to the anisotropic growth. Inspiringly, the 2D hexagonal FeSe exhibits intrinsic antiferromagnetic order rooted in Fe2+ and semiconductor nature. In addition, the temperature variation would result in the chemical environment changes of Fe2+, responsible for the temperature-dependent magnetic transitions. This work promotes the potential applications of 2D hexagonal FeSe and the preparation of other 2D nvdWs materials.

While serious stability issues impede the commercialization of perovskite solar cells (PSCs), two-dimensional (2D) perovskites based on fluorinated bulky cations have emerged as more intrinsically stable materials. However, the influence of fluorination degree of the bulky aromatic cation on the performance of resulting PSCs has not been scrutinized. Here, 2D perovskites (FxPEA)2PbI4 (x = 1, 2, 3, 5) are grown in situ on the surface of the three-dimensional (3D) perovskite and demonstrate effective passivation of the surface defects of 3D perovskite. The power conversion efficiency (PCE) of the optimized devices were boosted from 20.75% for the control device to 21.09%, 22.06%, 22.74% and 21.86% for 2D/3D devices treated with 4-fluorophenethylamine iodide, 3,5-difluorophenylethylamine iodide, 2,4,5-trifluoroethylphenylethylamine iodide, and 1,2,3,4,5-pentafluorophenylethylamine iodide, respectively. We firstly reported two unexplored RP-type layered perovskites with F2PEAI and F3PEAI as bulky cations. The combined experimental and theoretical analysis revealed the reasons behind the various morphology, device performances, dynamic behavior, and humidity stability. The best performing F5PEAI-treated device retaining 95.0% of its initial PCE under ambient atmosphere (with RH of 60% ± 5%) without encapsulation for 300 h storage. This work provides useful guidance for selecting fluorinated bulky cations with different molecular electronic properties, which will play an essential role in further improving the performance/stability of PSCs for the sake of further commercialization.

As a practical microwave absorber, besides satisfying the basic broadband absorption performance, the density, cost, and process complexity are considerable factors in radar stealth and electromagnetic protection field as well. Here, a simple and economical structural absorber (SA) is proposed to remarkably broaden the absorption bandwidth of biochar from banana peel. By optimizing the size parameters of the unit cell, the optimal SA shows more than 90% absorption in the frequency range from 3.4 to 18 GHz by employing a lightweight porous carbon derived from sustainable biomass. The lightweight porous biochar endows SA low-density properties with surface density of only 0.574 g cm-2. In such SA, the greatly enhanced absorption performance is mainly originated from the synergistic effect of microscopic and macroscopic scales. By optimizing the pattern design of SA, the effective impedance is matched with free-space in a wide frequency, thus dissipating more electromagnetic waves through multiple resonances and edge scattering effects. Additionally, whether transverse electric or transverse magnetic polarizations, stable broadband absorption can be maintained in a wide incidence angle. Thus, this work provides a new prospect for waste utilization of banana peel and a facile low-cost route to greatly extend the microwave absorption bandwidth.

Sm3+ doped LaBMoO6 phosphors were prepared by using the solid-state reaction method. The microstructure, morphology, chemical element composition, absorption, luminescent performance, decay life and thermal stability of Sm3+ doped LaBMoO6 samples were studied. Sm3+ doped LaBMoO6 phosphors mainly emit orange light at 596 nm with a decay lifetime of milliseconds under the excitation of 405 nm. The chromaticity coordinates of Sm3+ doped LaBMoO6 samples are located in the orange region, which also have great thermal stability. The Sm3+ doped LaBMoO6 phosphors can be used as orange-emitting materials in W-LED devices.