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Ballistic impact and sealed chamber tests were performed on the steel-encased reactive material projectile (SERMP) to understand its behind-plate overpressure effect when impacting the thin aluminum plates. The reactive material encased with a 1.5 mm thick 30CrMnSiNi2A steel shell was launched onto the initially sealed test chamber with a 3 mm thick 2024-T3 thin aluminum cover plate. Moreover, the overpressure signals in the test chamber were recorded by pressure sensors. The experimental results indicate an unusual behind-plate overpressure effect: as the density of the projectile increases from 6.43 g/cm3 to 7.58 g/cm3 by increasing the content of tungsten powder, although its total chemical energy decreases, it produces a higher behind-target overpressure at a lower impact velocity. A theoretical model is proposed to predict the reaction length of reactive material inside the projectile based on one-dimensional shock wave theory to understand this unexpected result. In addition, the deviation between the actual energy release and the theoretical calculation results, also the variation of overpressure rise time are analyzed and discussed. As the analyses show, when the SERMP successfully penetrates the cover plate, an increasing density of the reactive material inside the projectile always means that the delaying rarefaction wave effect, an increase of its internal pressure and strain rate levels. These factors lead to the increase of the overpressure limit velocity and reaction extent of the reactive material, while the overpressure rise time decreases.

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.

AlSn20Cu alloy is currently one of the most widely used bearing materials, and its microstructure is the most important indicator in application. In this paper, AlSn20Cu alloy ingots were prepared by two methods: ordinary casting and semi-continuous casting, and deformation and annealing process of the two ingots were studied. Scanning electron microscope (SEM) and Image Pro Plus software were used to observe and analyze the evolution of the microstructure, and the morphological information such as the average grain size and area fraction of the Sn phase was quantitatively characterized. The effects of casting method, deformation temperature, deformation amount and annealing temperature on the morphology of Sn phase were studied in this paper. Compared with ordinary casting, the cooling rate of semi-continuous casting is higher, so the Sn phase is smaller, the casting defects are less, and the deformability of the alloy is better. The AlSn20Cu alloy prepared by ordinary casting has better deformability at about 140 °C, while the AlSn20Cu alloy prepared by semi-continuous casting can be rolled and deformed at room temperature. When the deformation is greater than 40%, after annealing at 250 °C, the average grain size of the Sn phase in the AlSn20Cu alloy prepared by semi-continuous casting is around one hundred square microns and the area fraction is more than 10%, and the Sn phase morphology is better than ordinary casting alloy under any processing conditions.

The wettability of graphene is critical for numerous applications but is very sensitive to its surface cleanness. Herein, by clarifying the impact of intrinsic contamination, i.e., amorphous carbon, which is formed on the graphene surface during the high-temperature chemical vapor deposition (CVD) process, the hydrophilic nature of clean graphene grown on single-crystal Cu(111) substrate was confirmed by both experimental and theoretical studies, with an average water contact angle of ∼23°. Furthermore, the wettability of as-transferred graphene was proven to be highly dependent on its intrinsic cleanness, because of which the hydrophilic, clean graphene exhibited improved performance when utilized for cell culture and cryoelectron microscopy imaging. This work not only validates the intrinsic hydrophilic nature of graphene but also provides a new insight in developing advanced bioapplications using CVD-grown clean graphene films.

Traditional inorganic materials exhibit rigidity owing to the lack of polymer chains in polymer materials or atom slipping in metals. However, nanometerization has been recently proposed for the conversion of inorganic oxide materials into flexible materials. Herein, the flexible inorganic luminescent material, CaTiO3:0.2%Pr3+, was synthesized through electrospinning, and the macroscopic flexibility of pure inorganic CaTiO3:0.2%Pr3+ was achieved. The flexible membrane was characterized via X-ray diffraction, thermogravimetry, scanning electron microscopy (SEM), and photoluminescence analyses. The grain size was analyzed at various calcination temperatures via SEM, and the results suggested that the increase in the calcination temperature resulted in the growth of crystal grains. Studies have reported that the growth of crystal grains is beneficial for improving the luminescence performance; however, to obtain better flexibility, smaller crystal grains are required. This study provides an important reference for the design of flexible inorganic materials.

The flow stress curves of a Nb–Ti microalloyed C–Mn–Al high strength steel were obtained by hot compression experiment with Gleeble-1500 thermal simulator at the temperatures from 900 to 1100 °C and strain rates from 0.01 to 30 s−1. Firstly, strain-compensated physical constitutive models considering the temperature dependence of Young's modulus (E) and austenite self-diffusion coefficient (D) with creep stress exponent 5 and variable stress exponent $$n^{\prime}$$ were established, respectively. Secondly, the traditional apparent Arrhenius constitutive model was established to compare the accuracy of the models. The results show that the physical constitutive model with exponent $$n^{\prime}$$ has higher accuracy to predict the flow stress of the experimental steel (correlation coefficient R = 0.992, average absolute relative error δ = 3.83%) than the model with exponent 5 (correlation coefficient R = 0.990, average absolute relative error δ = 10.54%). This is because when the stress exponent in the physical constitutive model is 5, it means that the deformation mechanism considered is only slip and climb, and the constitutive model with variable stress exponent $$n^{\prime}$$ considers all the deformation mechanisms comprehensively, so the prediction accuracy is higher. The correlation coefficient R of the Arrhenius constitutive model is 0.991, and the average absolute relative error δ is 4.58%. Therefore, the physical constitutive model with exponent $$n^{\prime}$$ has the highest prediction accuracy in this study, thus can be an alternative way to predict the flow curves of steels.

We experimentally design an integrated system composed of a conveyor belt and a posts array, which can simultaneously implement the function of size separation and transportation of disk particles. Differently sized particles through the post array exhibit two types of distinct migration modes that are responsible for the size separation. Furthermore, the dividing line between the two migration modes depends on the critical radius found in experiment. The relationship between the separation efficiency and the length of the post array and the packing fraction of particles is investigated quantitatively. Finally, a simplified model is proposed to predict a critical particle radius which is verified to be in accordance with experimental measurements. This research has a potential application prospect in some fields of industry.

Cryo-electron microscopy (cryo-EM) has emerged as a vital tool to reveal the native structure of beam-sensitive biomolecules and materials. Yet high-resolution cryo-EM analysis is still limited by the poorly controlled specimen preparation and urgently demands a robust supporting film material to prepare desirable samples. Here, we developed a bilayer Janus graphene membrane with the top-layer graphene being functionalized to interact with target molecules on the surface, while the bottom layer being kept intact to reinforce its mechanical steadiness. The ultraclean and atomically thin bilayer Janus membrane prepared by our protocol on one hand generates almost no extra noise and on the other hand reduces the specimen motion during cryo-EM imaging, thus allowing the atomic-resolution characterization of surface functional groups. Using such Janus membranes in cryo-EM specimen preparation, we were able to directly image the lithium dendrite and reconstruct macromolecules at near-atomic resolution. Our results demonstrate the bilayer Janus design as a promising supporting material for high-resolution cryo-EM and EM imaging.

Effects of different solution treatments on microstructure, texture and mechanical properties of 6A16 aluminum alloy sheet were investigated by electron back-scattered diffraction (EBSD) and tensile test. The results show that among the five solution treatments, with the increase of solution temperature and solution time, the average grain size increases and the yield strength of the alloy sheet gradually increases. The maximum elongation at break of the sheet is at 545 °C, and it increases with the increase of solution time. Therefore, the mechanical properties of the sheet are the best when the solution treatment is 545 °C for 5 min.

The second phase dissolution of Al-9.2Zn-2.0Mg-1.9Cu alloy conducted by various temperatures of 2h was researched with the help of optical microscope (OM), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), electrical conductivity and differential scanning calorimetry (DSC) analysis. The results gave rise to the second phase existence of Mg(Zn,Cu,Al)2 and Fe-containing phases in the as-extruded alloy. When the alloy solution treated with a temperature varied from 450°C to 470°C, a small quantity of Mg(Zn,Cu,Al)2 phase still existed in the alloy while its content exhibited a decrement trend with the solution temperature rose. For the alloy solution treated at a temperature of 475°C, Mg(Zn,Cu,Al)2 phase dissolved into the matrix completely while Fe-containing phase still remained. The electrical conductivity of quenched alloy decrease with the solution temperature increase and reached a minimum value at 470°C, and then rose slightly for the solution temperature of 475°C.

To solve the problem of difficult utilization of steel slag, the liquid steel slag was modified and the air-quenching granulation process was carried out to make steel slag into a value-added end product: air-quenching granulated steel slag. The granulated slag was tested to analyze the variation rule of slag properties under different modification conditions. Based on the phase diagram of CaO–Si2O–FeO–MgO–Al2O3 slag system, the feasibility of blast furnace (BF) slag as modifier was determined. When the addition of BF slag was increased from 0% to 35%, following results were obtained. The slag fluidity was improved, and the air-quenching temperature range was expanded. Then, the yield of air-quenched steel slag increased, while the granulation rate, the degree of sphericity, the compactness were decreased. Furthermore, the air-quenching granulation process could substantially improve the stability and the amorphous content of steel slag. The maximum removal rate of free CaO was above 80% and the amorphous content was up to 95%. Taking the factors of yield and properties of granulated steel slag into full consideration, the optimum proportion of BF slag is around 15%.

The rapid development of the automotive industry has led to the accumulation of a large number of waste tires that contain a lot of reusable energy. Macromolecular organics in waste tires can be crack small molecule organics via pyrolysis. In this experiment, thermogravimetry (TG) and pyrolizer-gas chromatography/mass spectrometry (PY-GC/MS) were used to study the pyrolysis behavior of waste tires with different particle sizes, and the effect of temperature and particle size on the pyrolysis products of waste tires under low-temperature pyrolysis conditions, respectively. The volatile substances in waste tires decomposed intensively at 300-500�C and were completely pyrolyzed at 500�C. The content of limonene in the pyrolysis product was significant, and the yield of limonene could reach 27.73% when the waste tire particles were 0.180-0.250 mm and the pyrolysis temperature was 380�C. The mechanism of limonene formation from waste tires was discussed. This study indicated that raw material particle sizes and pyrolysis temperature could change the components and content of pyrolysis products.

Developing n-type materials with high peak and/or average ZT (ZT is the figure of merit) is an urgent need for the lower ZT of the existing n-type BiTeSe materials compared with the p-type BiSbTe materials. Here, we demonstrate that liquid-phase sintering can lead to lowered thermal conductivity and an improved power factor in n-type Ag2Se, which originates from the greatly lowered electronic thermal conductivity attributed to the decreased mobility and improved Seebeck coefficients because of increased effective mass. Benefiting from this, the maximum ZT (ZTmax) of ∼1.21 and the average ZT (ZTave) of 1.06 are successfully achieved in polycrystalline Ag2Se. In this work, ZTave is the highest reported value, being 26% larger than that of Ag2Se reported. Our work shows that liquid-phase sintering to achieve improved thermoelectric (TE) performance opens a great opportunity for designing prospective thermoelectrics.

The gold deposits in the Jiaodong Peninsula constitute the largest gold mineralized province in China. The mineralization shows common characteristics in their tectonic setting, ore-forming fluid and metallogenic system. Sulfidation and fluid immiscibility are two important mechanisms controlling gold precipitation, both of which consume sulfur in the ore-forming fluids. The escape of H2S from the main ore-forming fluids and the decrease of total sulfur concentration not only lead to the efficient precipitation of gold, but also result in the crystallization of reducing minerals such as pyrrhotite and oxidizing minerals such as magnetite. Quartz solubility shows strong dependence on temperature, pressure, and CO2 content. The dependence of quartz solubility on pressure is weak at low temperatures, and progressively stronger at higher temperatures. Similarly, the temperature dependence of quartz solubility is relatively low at low pressures, but becomes gradually stronger at high pressures. The results of solubility modeling can constrain the dissolution and reprecipitation behavior of quartz in the ore-forming veins and the formation mechanism of different types of quartz veins. The multi-stage mineralization fluid activity resulted in the complex dissolution structure of quartz in the Jiaodong gold veins. Pyrite in the main metallogenic period in the Jiaodong gold deposits shows complex microstructure characteristics at single crystal scale. The trace elements (mainly the coupling of As- and Au-rich belt) and sulfur isotope composition also display a certain regularity. The As-rich fluids might have formed by the initial pulse of ore-forming fluids through As-rich metasedimentary strata, while the As-Au oscillation zone at the margin of pyrite grains is related to the pressure fluctuation caused by fault activity and the local phase separation of fluids. There is a temporal and spatial evolution of gold fineness in the Jiaodong gold deposits. Water/rock reaction (sulfidation) was the main ore-forming mechanism of early gold mineralization, forming relatively high fineness gold, while significant pressure drop in the shallow part accompanied by fluid phase separation promoted the late gold mineralization, forming low fineness gold. Under cratonic destruction setting, dehydration of the amphibolite and granulite facies metamorphic lower-crust resulted in the formation of Au-CO2-rich ore-forming fluids, which rose along the deep fault and secondary structure, and formed the largescale fault-controlled gold deposits in Jiaodong.

Perforated structure is the mechanical weak link of polymer-bonded explosive (PBX). Improving its mechanical property may promote the reliability and effectiveness of weapon system. In this study, strengthening of the perforated PBX plate is conducted by employing surface coating. Digital image correlation (DIC) analysis results suggest that the regional applied epoxy coating layer is able to improve the mechanical properties of the plate. By confining the deformation and releasing the stress concentration around the perforation, the coating layer enhances the load carrying ability and energy dissipation capacity of the plate significantly. This investigation may provide a convenient and effective structure modification method for energetic material, and at the same time, lay foundation to the performance optimization of weapon system.

Defect-rich metal-based nanomeshes have been regarded as potential effective catalysts for electrocatalytic water splitting, in which nanopores are beneficial to increase active sites and enhance the mass transfer. However, facile synthesis of metal-based nanomeshes still remains a great challenge. Herein, we report the cost-efficient ultrathin nickel molybdenum nanomeshes (NiMoO4) for overall water splitting. The NiMoO4 possesses outstanding oxygen evolution reaction property (239 mV@10 mA cm−2), together with an exceptional cycling stability. Notably, phosphorus (P)-doping endows the NiMoO4 nanomeshes a superior hydrogen evolution reaction property (144 mV@−10 mA cm−2). We also prepare a double electrode system with NiMoO4 and P-doped NiMoO4, and evaluate the performance of overall water splitting (1.68 V @10 mA cm−2). The key point of the processing route developed here is the synergistic effect between defect engineering and element doping, which provide a guiding insight for the development of novel catalysts for their practical applications.

Moisturizing strategy that controls the water evaporation rate of the wet material and thus the relative humidity in the drying chamber was proposed for hot air drying of mushroom slices for the first time. To assess the effectiveness of moisturizing strategy, drying kinetics, moisture diffusivities, mass transfer coefficients, surface color and rehydration capacity of dried products, energy and exergy efficiencies were evaluated. Mushroom slices were dried at constant drying temperature of 60 °C and air velocity of 3 m/s. The strategies of moisturizing for 0, 15, 30, and 45 min were applied in the initial drying stage. Compared to the continuous dehumidifying strategy (moisturizing time is 0 min), the strategies of moisturizing for 15 and 30 min reduced drying time by 5% and 15%, respectively. The proper moisturizing time (30 min) enhanced the heat transfer by increasing the enthalpy of the drying air, improved surface color, and increased rehydration capacity of dried mushroom slices by reducing cell shrinkage. The energy utilization and energy utilization ratio of drying process varied from 0.16 to 3.48 kJ/s and 0.065 to 0.572, respectively, while the exergy efficiency varied from 8.04% to 84.66%. The strategy of moisturizing for 30 min reduced 23.4% total energy utilization compared to continuous dehumidifying strategy. Both the highest average energy utilization ratio, i.e. 0.156 and average exergy efficiency, i.e. 70.19% were obtained for moisturizing time of 30 min. The increase of moisturizing time from 30 to 45 min showed an adverse impact on drying time, energy utilization ratio, exergy loss, and exergy efficiency due to the inhibition of water evaporation. This study shows that moisturizing strategy can be considered as a promising method to enhance energy and exergy efficiency of hot air dryer with the improvement of products quality and sustainability of drying systems.

In recent years, with the urgent need of the country to vigorously promote the transformation and upgrading of the construction industry and the modernization of the construction industry, it has been proposed to vigorously develop prefabricated buildings and increase the proportion of prefabricated buildings in new buildings. The prefabricated concrete building is a concrete structure with prefabricated components in the factory and processing and connection on the construction site. Because of its fast construction speed and good overall benefits, it is widely promoted. For prefabricated buildings, the key technology is the connection of structural nodes, and most of the component connections use concrete sleeve connections. The quality of the sleeve grouting material is very important. The basic formula of the grouting material leads to different and different mechanical properties. Conditions apply. This article starts with different sleeve grouting patents, summarizes different functions and characteristics, and provides a reference for the next development of sleeve grouting.

Second phase dissolution of Al-Zn-Mg-Cu alloys during solution treatment was closely associated with the content of main alloying elements. In present work, the phase characteristics of several Al-Zn-Mg-Cu alloys with various main alloying contents were investigated, and the second phase dissolution of these alloys during solution treatment was analyzed. The results showed that the extrusion alloys possessed abundant second phases, mainly including Mg(Zn,Cu,Al)2 phase and Fe-rich particles. The DSC analysis proved that the larger endothermic peak corresponded to the alloy with larger main alloying content, and the XRD spectrogram also backed up the advantage of Mg(Zn,Cu,Al)2 phase. After solution treated at 450°C, the residual phases remained in the alloys and the quantity of them were positively correlated with the main alloying content. With the increase of solution temperature, the electrical conductivity of the alloys showed a decremental trend, while the alloys with relatively low main alloying contents exhibited an inversion at the solution temperature of 475°C. The SEM observation demonstrated that no Mg(Zn,Cu,Al)2 phase was observed in the alloys with relatively low main alloying contents while seldom still remained in the alloy with high main alloying content after solution treated at 470°C. After solution treated at 475°C, Mg(Zn,Cu,Al)2 phase completely dissolved into the matrix for the alloy with high main alloying content. The statistics of residual phase quantity also proved this.

Earphones are often exported to foreign countries by sea as consumer goods. In view of the humid marine environment, the earphone packaging box is often placed with anti-mold chips to prevent mold, while the volatilization of the anti-mold chips will also cause corrosion problems. In this study, a large number of aluminum earphone connectors were corroded in the process of ocean transportation, and the corrosion products were located in the left earphone connector close to the anti-mold chips. It’s determined that sulfate and nitrate ions lead to the corrosion of the aluminum connectors, and these are the volatilization products of the anti-mold chips. This conclusion was further confirmed by the simulation test, which was carried out on the anti-mold chips and aluminum connectors at 85 °C, 85% RH humidity for 72 h. The aluminum connectors were obviously corroded, and the morphology and composition of the corrosion products were the same as those on the actual earphones. The corrosion was successfully prevented by a PTFE coating on the surface of aluminum connectors. Keywords: Earphones; Anti-mold chip; Aluminum; Corrosion; PTFE coating

As a natural cellulose fiber, kapok fiber is much easier to degrade due to its thin wall structure of fiber in the process of storage and use. In this work, a finishing modification was designed and developed to prevent kapok fiber from degradation. Dopamine was polymerized in situ and deposited on the surface of kapok fiber, which was operated in the mixed solvents of ethanol:water (1:1 in volume) to overcome the strong buoyancy. Polyethyleneimine (PEI) was introduced to assist dopamine polymerization and improve the load rate. An optimum dosage, 1.0 g/l of PEI could afford the highest loading rate of 32.1% of polydopamine (PDA), and remarkably improve loading fastness. As a multi-amino polymer, PEI could reduce Ag+ and chelate with metal silver (Ag). The PDA/Ag covered kapok fiber and nonwovens showed good antibacterial activity and better mechanic strength, which would be more suitable for durable oil absorption and sound absorption materials than pure kapok fiber.

Emission of fine dusts and nitrogen oxides (NOx) causes increasingly serious environmental pollution problems during the industrial combustion of solid fuels. This study was designed to develop an integrated filtration material for both fine dust removal and denitration applications. Polyphenylene sulfide (PPS) needle-punching fibrous felts (NPFFs) were employed as the main materials to get rid of the fine dusts in the high-temperature flue gas. We further loaded manganese oxides (MnO2) onto PPS NPFFs as the ammonia selective catalytic reduction (NH3-SCR) catalysts to reduce NOx existed in the high-temperature flue gas. An in-situ deposition process was utilized to load MnO2 onto the PPS NPFFs. And a plasma pretreatment method was firstly employed to activate the PPS NPFFs before the in-situ deposition process to help improve the catalyst load rate. This notably increased the denitration activity in comparison with those without plasma pretreatment. We also found that all the PPS/MnO2 NPFFs exhibited significantly enhanced dust-removal properties compared with pure PPS NPFFs. Overall, the novel PPS/MnO2 NPFFs with stable structure, great handling convenience, excellent dust-removal property as well as high denitration performance, were designed and developed in this study, which showed great application potential in the high temperature fuel gas purification field.

The atomic diffusion in transition metal dichalcogenides (TMDs) van der Waals heterojunctions (HJs) strongly modifies their optoelectronic properties in the nanoscale. However, probing such localized properties challenges the spatial resolution and the sensitivity of a variety of analytic tools. Herein, a multimodal nanoscopy (based on tip enhanced Raman spectroscopy (TERS) and photoluminescence (TEPL)) combined with the Kelvin probe force microscopy (KPFM) method was used to probe such nanoscale localized optoelectronic properties induced by atomic diffusion. Chemical vapor deposition (CVD)-grown lateral bilayer (2L) WS2/MoS2 HJs were imaged with a spatial resolution better than 40 nm via TERS and TEPL mapping by using intrinsic Raman and photoluminescence (PL) peaks. The contact potential difference (CPD), capacitance, and PL variation in a nanoscale vicinity of the HJ interface can be correlated to the local stoichiometry variation determined by TERS. The diffusion coefficients of W and Mo were obtained to be ∼0.5 × 10-12 and ∼1 × 10-12 cm2/s, respectively, by using Fick's second law. The obtained results would be useful to further understand the localized optoelectronic response of the TMDs HJs.

Inorganic perovskite absorbers are promising candidates for next-generation photovoltaics due to their good thermal and light stabilities. Halide-mixed CsPbIxBr3−x reach a compromise between its structural tolerance and absorption edge, yet the power conversion efficiencies (PCEs) of the asfabricated cells can be considerably limited by the nonideal quality of solution-processed films. Here we demonstrated a fumigation strategy on colloidal perovskite films using dual-O-donor ethyl acetate (EA). By in-situ monitoring this stage with grazing-incidence wide-angle X-ray scattering technology, we reveal that EA fumigation would impose ripening barrier on colloidal inorganic perovskites and hence slow down the nucleation rate, leading to an intermediate state for processing high-crystallinity and oriented perovskite films with improved photophysical properties. An optimized PCE of 16.6% was finally yielded upon wide-bandgap (1.9 eV) perovskite absorber.

This paper proposes and designs a (Graphene/TiO2/Metal/TiO2/Graphene)N structure based on the symmetrical periodic arrangement of graphene photonic crystals, metals and titanium dioxide. In a single layer of this structure, nano-scale metal materials are used as the center. Graphene and titanium dioxide materials are arranged symmetrically to form a period. The transfer matrix method is used for the numerical simulation study of the GPC (Graphene Photonic Crystals) structure in the ultraviolet, visible light and near-infrared ranges. The optical response of the GPC structure under different parameters (periods, TiO2 thickness and metal layer thickness) is analyzed. The results are displayed in the ultraviolet, visible light and near-infrared band, this structure can accurately shield and reflect ultraviolet and near-infrared, while maintaining a high transmittance in the visible band, which is conducive to improving the growth quality and yield of plants. Greenhouse covering materials have high potential application prospects in the field of agriculture.

Both microstructure inhomogeneity and mechanical property diversity along the thickness direction in rolled thick aluminum plates have been considered to have a remarkable impact on the performance and properties of the products made from the plates. In this study, scanning electron microscopy (SEM) and electron backscattered diffraction (EBSD) characterizations of microstructure and texture types along the thickness directions of Al7055 thick plate specimens prepared using two conditions, hot-rolling and solution-quenching, were performed. To examine the mechanical properties, uniaxial tensile tests were also carried out on specimens machined from both types of thick plates, using a layered strategy along the thickness direction. The results indicate that both the microstructure and mechanical properties are inhomogeneous under the two conditions. Furthermore, it is evident that there is a hereditary relationship between the mechanical properties of the two plates—areas with higher yield strength in the as-hot-rolled plate correspond to areas with the higher yield strength in the as-solution-quenched plate

The fatigue crack growth of Al-Zn-Mg-Cu alloy can be adjusted by different aging treatments. In the present work, a high Zn-containing Al-Zn-Mg-Cu alloy was treated by single, double and triple stage aging treatments and typical T6, T79 and T77 states were selected by tensile properties. Fatigue crack growth under these aging states was tested and related fracture morphology and precipitation characteristics were observed. The results showed that fatigue crack growth resistance for the alloy was T6

In the present work, an efficient four-step strategy to fabricate the Fe-Co-P porous nanowire arrays in situ grown on a self-supported carbon cloth (denoted as Fe-Co-P/CC) for developing excellent HER activity is reported. The four steps include the preparation of the CoFeZn-precursor by a hydrothermal reaction, the formation of pore-forming agent (ZnO) after annealing treatment, the alkaline etching of ZnO, and phosphorization. Particularly, the alkaline-etched porous Fe-Co-P nanowire-arrays contribute to enhancing the catalytic activity by the exposure of more electrochemical active sites. The as-prepared Fe-Co-P/CC which was prepared by the rational Co-Fe molar ratio, as a binder-free electrocatalyst, shows a high-performance HER with a small overpotential of 121 mV in 1 M KOH and 124 mV in 0.5 M H2SO4 at a current density of 10 mA·cm−2, as well as a good Tafel slope value of 118 mV/dec and 85 mV/dec in alkaline and acid media, respectively, owing to the well-optimized pore-structures and active sites. Additionally, the catalyst almost maintains its electrochemical activity for about 24 and 16 h under alkaline and acidic conditions, respectively. This work provides a new idea for the synthesis of high-efficiency, binder-free electrodes for high-purity hydrogen production.

A 100 kW solid target was successfully developed for the CSNS phase one. Tungsten was selected as the CSNS target material and a layer of tantalum with a thickness of only 0.3mm as a protective layer. Eleven target blocks were fixed in parallel in a stainless steel target container with 1.2mm gap between each block. Using a specially designed spreader, the target plug can be easily replaced. The parameters of the target were stable and normal in the course of more than a year of operation, the temperature rise of the target cooling water inlet and outlet increased as the proton beam power increased.

A bandpass filtering nano-film based on high refractive index materials is designed in this paper, it shows high transmittance for red light and high reflectance for visible light. The structure of the nano-filtration membrane is simple, which is composed of three nano-films with the overall thickness no more than 100 nm. At normal incidence, the red light (620-760nm) transmittance of the filter film is above 0.6, and the reflectance is below 0.05. At oblique incidence from 0 to 45 degree, the red light transmittance of the filter film under both TM and TE wave mode are all above 0.5, which achieve the transmission of red light in a wide range of incident angles. The light transmittance of the nano-filtration membrane was calculated by transfer matrix method (TMM), it is verified by finite-difference frequency-domain (FDFD) method, and the field distribution of the typical wavelength in the film was calculated. The thickness variation of each layer effects the transmittance of light wave in nano-film was studied. The passband of this filter is easy to be modulated, the bandwidth and waveband of the transmitted light can be modulated as long as changing the thickness of the film, which can be applied to medical or scientific research fields that requires specific light waveband.

The C60 concrete blocks with surface crack damage under high temperature environment were soaked by adding appropriate amount of soybean urease into the CO(NH2)2-CaCl2 solution, the soybean urease mineralized calcium carbonate were characterized, and the effect of repairing concrete surface crack damage were evaluated by the surface sedimentation of C60 concrete blocks in the study. The experimental results showed that the activity of soybean powder was statistically significant, and its productivity of urease was comparable with that of urease-producing bacteria. After immersion in a soybean solution, a layer of complete and continuous white sediment covered the concrete surface. The cracks on the concrete surface were completely shielded, and the rising temperature on infrared thermal image of the concrete after repair was lower than before. Besides, through analysis by SEM, EDS, and XRD, the products formed after repair were found to be calcite-type CaCO3 with high purity, and the crystals exhibited different morphological features. The above results indicate that soybean urease can regulate and induce the formation of calcium carbonate, and the precipitate is innocuous and harmless, suitable for a new type of concrete crack repair material.

The effects of three different drying tecnologies (PVD, THC-HAD, and IR-HAD) on drying kinetics, microstructure, energy consumption, and quality, that is, rehydration ratio (RR), color parameters (...

Although single-particle cryogenic electron microscopy (cryo-EM) has been applied extensively for elucidating many crucial biological mechanisms at the molecular level, this technique still faces critical challenges, the major one of which is to prepare the high-quality cryo-EM specimen. Aiming to achieve a more reproducible and efficient cryo-EM specimen preparation, novel supporting films including graphene-based two-dimensional materials have been explored in recent years. Here we report a robust and simple method to fabricate EM grids coated with single- or few-layer reduced graphene oxide (RGO) membrane in large batch for high-resolution cryo-EM structural determination. The RGO membrane has decreased interlayer space and enhanced electrical conductivity in comparison to regular graphene oxide (GO) membrane. Moreover, we found that the RGO supporting film exhibited nice particle-absorption ability, thus avoiding the air–water interface problem. More importantly, we found that the RGO supporting film is particularly useful in cryo-EM reconstruction of sub-100-kDa biomolecules at near-atomic resolution, as exemplified by the study of RBD-ACE2 complex and other small protein molecules. We envision that the RGO membranes can be used as a robust graphene-based supporting film in cryo-EM specimen preparation.

Perovskite solar cells (PSCs) have been attracting increasing attention in recent years because of their exceptional high efficiency with incredible developments. However, the poor contact between the hole transport layer (HTL) and perovskite layer still limits the further development of power conversion efficiency (PCE) for inverted solar cells, particularly for inorganic HTL based devices. Herein, potassium salt (KI, KSCN and KNO3) modified nickel oxides are selected as HTLs to improve the photovoltaic performance of an inverted device. We found that all potassium salts play positive roles in optimizing the photovoltaic parameters. Through the modification of potassium salts, higher charge recombination impedance and strong photoluminescence quenching were achieved, which means retarded carrier nonradiative recombination and quick charge transfer at the interface. Besides, KI modified NiOX could improve the perovskite film coverage and reduce trap densities. Thus, the champion device based on a KI modified NiOX film attained a PCE of 20.10% with an enhanced fill factor of 0.812. The findings demonstrate that potassium doping is an effective route to improve the performance of inverted planar PSCs.

Unlike silicon carbide ceramic, the alumina ceramic and zirconia ceramic are by its very nature weakly absorbing in visible and near infrared wavebands. Therefore, open-cell foams made of such ceramics are rarely used in applications requiring strong absorption of radiation energy, such as solar absorbers. In order to improve the potential of such foams, open-cell foams with dual-scale pores were digitally designed in the limit of geometric optics. The first-order pores are obtained by Voronoi tessellation technique and then the second-order pores are realized by the design of 'porous strut'. A Monte Carlo Ray-tracing method is applied in the dual-scale foam structure for radiative transfer calculation. The parameterized study is conducted on the radiation absorption of alumina foam sheets and zirconia foam sheets. The results show that for the present cases, the designed dual-scale alumina foams with strut porosity p s = 0.3 can increase the normal absorptance within the wavebands from 0.4 μm to 7.0 μm by 62.7% than the foams with single-scale pores. For the zirconia foams, this increase is 115.9% within the wavebands from 1.2 μm to 7.6 μm. The findings can provide strong confidence on dual-scale foams to enhance the absorption of radiation energy in potential applications.

Graphite-like carbon nitride (g-C3N4) has attracted great attention for pollutant degradation and clean energy production. The heterojunctions of bismuth halide (BiOX, X = Cl, Br, I) and g-C3N4 are proposed to overcome the shortcomings of the g-C3N4 photocatalyst, such as low charge separation rate and high charge recombination rate. This review paper systematically discusses the progress in synthesis, structure, and applications of heterojunction photocatalytic composites made of g-C3N4 and BiOX based on the understanding of their photocatalytic reaction mechanism. We clarify and summarize structural mechanisms of a single and compound semiconductor to reveal the factors that affect photocatalytic performances. We discuss and compare advantages and disadvantages of versatile preparation processes. Particularly, we focus on the understanding of the structure and characteristics of type II, Z-type, n-n, and p-n heterojunctions and their applications, specifically in pollutant degradation, H2 production by water splitting, CO2 reduction, and medical sterilization. The future prospects of g-C3N4/BiOX composites are also discussed from aspects of their preparation, application, and research methods. This work may offer a good avenue and data reference to develop novel g-C3N4 photocatalytic materials to meet the ever-increasing environmental pollution and energy shortage.

Metal halide perovskites (MHP) are an emerging class of semiconducting materials with superior optoelectronic properties, which have achieved notable success in photoelectric device applications. As a classical technique in the semiconductor industry, epitaxy has indeed advanced the perovskite technology in the recent years by enabling the material combinations with a coherent interfacial lattice as well as combined complementary functionalities, which are not available in the single-phase constituents. In this review, we start with the basic principles and chemical techniques for the epitaxial growth of MHP-based materials. We summarize the epitaxial structures of perovskite solids, which are categorized by the combined materials and compare their performance in photoelectric devices including solar cells, photodetectors, and light-emitting diodes (LEDs). The impact of lattice strain and band structure at the substrate/perovskite interface, which can affect the energy conversion process, are then discussed after the epitaxial cases. We finally outline the future directions for perovskite epitaxy, targeting the in situ monitoring of the surface atomic kinetics during the growth, precise interfacial structure characterization, and the upscaling fabrications, which might further benefit the performance and application of perovskite-based devices.

Organic–inorganic hybrid perovskite materials have attracted enormous attention owing to their extraordinary progress in both power conversion efficiency and stability. However, nonradiative carrier recombination occurring in the perovskite films and interface hinders its commercial viability as the next-generation photovoltaics. Doping with metal cations has been demonstrated to be efficacious for controlling charge transport and reducing charge recombination for perovskite solar cells. Herein, we report the homogeneous doping of entire perovskite solar cells by alkali cations via a dopant diffusion strategy from the hole transport layer. It was found that Rb+ ions enhanced the conductivity and optimized the energy level alignment. The diffused Rb+ ions within the perovskite layer could further reach the bulk films with modulated electronic states. The power conversion efficiency of the perovskite solar cell based on 1.0% Rb+-doped NiOx boosts to 21.80% with a high fill factor of 0.824. Unencapsulated Rb+-doped NiOx photovoltaic devices maintained 93.3% of their initial efficiency after storage in air for 1200 h.

Fuel-driven dissipative supramolecular assemblies in biology, such as actin filaments and microtubules contribute to the formation of complex, dynamic structures in living organisms and give rise to emergent functions such as motility, homeostasis, self-healing, and camouflage. Several synthetic dissipative supramolecular materials have been created using chemicals or light as fuel, with the goal of furthering our understanding of biological systems and creating synthetic materials that have life-like dynamic properties. However, electrical energy, one of the most common energy sources, has remained mostly unexplored for such purposes. Here we demonstrate the use of electrically fueled dissipative assembly as a new platform for creating active supramolecular materials. Through an electrochemical redox reaction network operating in mild aqueous buffers, a transient and highly active supramolecular assembly based on a redox-sensitive cysteine derivative is achieved by applying an electric potential. The dissipative self-assembly as well as its emergent properties can be spatiotemporally controlled by modulation of electrical signals on patterned microelectrodes. Using electrical energy as a readily available and clean fuel, we are able to create dissipative supramolecular materials rapidly (in seconds to minutes) and repetitively under mild conditions with directional and spatiotemporal control. As electronic signals are the default information carriers in modern technology, the described approach offers a promising opportunity to integrate active materials into electronic devices for bioelectronics applications.

Intermediate annealing on anisotropy and mechanical properties of an Al-0.78Mg-0.90Si-0.65Zn-0.16Cu (wt. %) alloy was investigated by tensile test, optical microscope (OM) and electron back-scattered diffraction (EBSD). The results indicated that alloy sheet displayed various microstructure after without intermediate annealing, intermediate annealing treatment at 350°C for 2 h, 450°C for 2 h and 500°C for 5 min. Compared with the alloy without intermediate annealing, the alloy exhibited equiaxed grain with 35.0µm after annealing at 500°C for 5 min, grain orientation of the alloy was distributed randomly, and plastic strain ratio value of 45° direction was more than 0.6. The anisotropy of the sheet was significantly reduced. Annealing at 500°C for 5 min was suitable for the production process of automobile body sheets.

In order to analyze aging behavior of an Al-8.0Zn-1.8Mg-2.0Cu alloy, the microstructure of the alloy subjected to T6 and T76 states are investigated by transmission electron microscopy (TEM) and high-resolution electron microscopy (HREM). Based on the precipitate observations, precipitate size distributions and average precipitate size are extracted from bright-field TEM images projected along 〈110〉Alorientation with the aid of an imaging analysis. The results indicate that the main precipitates are GPI zone, GPII zone and η' phase in the T6 alloy while η' phase and η phase in the T76 alloy. The bright-field TEM observations reveal that the matrix precipitates for the T6 alloy have small size and dispersive distribution while that for the T76 alloy has big size and sparse distribution. Both have discontinuously distributed grain boundary precipitates. Quantitative structural information including precipitate size distribution and average precipitate size has been calculated by an image analysis based on the bright-field TEM images projected along 〈110〉Alorientation. The results show that the T6 alloy has a narrower precipitate size range than the T76 alloy and thus the T6 alloy possesses a smaller average precipitate size than the T76 alloy.

Aging treatments of an Al-9.0Zn-2.0Mg-2.0Cu alloy, which belongs to high strength aluminum alloy widely used in aerospace industry, are investigated by various techniques, including hardness, electrical conductivity, mechanical properties, transmission electron microscopy (TEM) and high-resolution electron microscopy (HREM). The result shows that hardness and conductivity for one-step aging treatment increase with aging time prolongs while those for two-step aging treatment exhibit increment and decrement, respectively. Besides, the ultimate tensile strength (UTS) and yield strength (YS) for one-step and two-step aging treatments show slow increase and obvious decrease, respectively. Based on these, typical T6 and T76 aging regimes are extracted for microstructure observation. The matrix precipitates for the T6 alloy have small size and dispersive distribution while that for the T76 alloy has big size and sparse distribution. The grain boundary precipitates for both exhibit discontinuous distribution and the T76 alloy has larger size and broader precipitate free zones. The selected area diffraction patterns and HREM observations reveal that main precipitates for the T6 alloy are GPI zone, GPII zone and η' phase while for the T76 alloy are η' phase and η phase.

Three methods of shade (MI), open sun (MII) and new designed of solar (MIII) drying were used for peppermint dehydration. The air velocity (u) and temperature (Td ) of MI, MII and MIII were 0.5, 0....

In current work, the effects of drying temperature (60, 65, 70, and 75 °C), vacuum pressure duration (VPD; 6, 9, 12, and 15 min), and ambient pressure duration (APD; 2, 3, and 4 min) on drying kine...

The development of an environmentally friendly binder can immensely benefit and promote the BF slag fiber industry. Accordingly, in this study, fiber insulation pipes were prepared using water glass, polyvinyl alcohol (PVA), and PVA–glutaraldehyde (GA); moreover, their bulk density, moisture absorption capacity, and thermal conductivity coefficient were measured and compared. The results demonstrated that the values of these three parameters depend on the binder concentration and dosage under certain fiber quality, pipe sizes, and manufacturing process conditions. The best binder composition was proven to be that of PVA–GA, prepared using 3 wt% PVA and 5 wt% GA herein, which facilitated reduction in the bulk density and improvement of the waterproof properties and insulation performance of the slag fiber pipes.