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Semiconductor photocatalytic technology has shown great prospects in converting solar energy into chemical energy to mitigate energy crisis and solve environmental pollution problems. The key issue is the development of high-efficiency photocatalysts. Various strategies in the state-of-the-art advancements, such as heterostructure construction, heteroatom doping, metal/single atom loading, and defect engineering, have been presented for the graphitic carbon nitride (g-C

Al-Mn-Fe-Si strips were fabricated via both the twin-roll casting (TRC) and the more conventional route, direct-chill casting (DC). The two types of strips prepared were subjected to thermal exposure at a series of temperatures. Uniaxial tensile tests after the thermal exposure showed that while the DC strip presented a ∼74% decrease in the yield strength and ∼35% decrease in the ultimate tensile strength (UTS) after being exposed to 350 °C for 12 h, the TRC strip, in contrast, maintained its strength at temperatures up to ∼460 °C for the same duration. Systematic microstructure characterization revealed that the different thermal stability in the strength of the two types of strips arised from their distinct evolution in grain morphology and second phase particles during the thermal exposure. The calculation based on Cahn-Lucke-Stuwe (CLS) model suggested that due to the highly supersaturated solute atoms, at the beginning of the thermal exposure, the TRC strip experienced a strong solute drag which reduced the grain boundary migrating velocity to a value that is orders of magnitude smaller than that in the DC strip. With the progress of the thermal exposure, the solute atoms precipitated out, forming densely distributed second phase particles. For one thing, these particles stabilized the grain structure by inducing Zener pinning pressure which could be ten times higher than that in the DC strip, depending on the temperature. For another, they acted as dislocation obstacles and compensated for the strength loss owing to decreasing solution hardening. Both effects contributed to the TRC strip's fairly stable strength regarding thermal exposure below 460 °C. The present work could guide the direct application of the TRC strips in the industry. The results should also be helpful for the development of a fundamental framework for designing advanced TRC Al strips with improved mechanical properties at elevated temperatures.

Heteroatom-doped carbon materials have demonstrated great potential in the electrochemical reduction reaction of CO2 (CO2RR) due to their versatile structure and function. However, rational structure control remains one challenge. In this work, we reported a unique carbon precursor of soft template-containing porous poly(ionic liquid) (PIL) that was directly synthesized via free-radical self-polymerization of ionic liquid monomer in a soft template route. Variation of the carbonization temperature in a direct pyrolysis process without any additive yielded a series of carbon materials with facile adjustable textural properties and N species. Significantly, the integration of soft-template in the PIL precursor led to the formation of hierarchical porous carbon material with a higher surface area and larger pore size than that from the template-free precursor. In CO2RR to CO, the champion catalyst gave a Faraday efficiency of 83.0% and a current density of 1.79 mA cm−2 at −0.9 V vs. reversible hydrogen electrode (vs. RHE). The abundant graphite N species and hierarchical pore structure, especially the unique hierarchical small-/ultra-micropores were revealed to enable better CO2RR performance.

The natural gas hydrate resources in the South China Sea alone are about 85 trillion cubic meters. In the drilling process of marine gas hydrate, the natural gas hydrate will decompose and produce gas, as the rising of temperature and dropping of the pressure in the annulus. This process will have a significant impact on drilling safety. Therefore, it is necessary to study the wellbore temperature distribution during the drilling of marine hydrate layer. In this paper, the wellbore temperature distribution of safe drilling in hydrated formation is taken as the research goal, and the research status of relevant domestic and international wellbore temperatures was investigated. According to the characteristics of the marine environment and reservoir-forming characteristics of hydrate reservoirs in the South China Sea, the wellbore temperature distribution model of offshore drilling wellbore under the condition of hydrate decomposition was established. The temperature distribution curve of drilling straight wellbore in hydrate layer of South China Sea was obtained. When drilling the hydrate reservoir, the distribution regularity of the wellbore temperature is similar to that of the conventional offshore drilling wellbore. However, the temperature of the wellbore annulus near the hydrate decomposition site is lower than the ambient temperature, mainly due to the hydrate decomposition endothermic. In this paper, the sensitivity analysis of several main parameters of the wellbore temperature distribution of drilling straight wellbore in hydrate layer of South China Sea was carried out. Through the conduction of experiment and numerical simulation, we have get some new findings: (1) The hydrate saturation has little effect on the wellbore temperature; (2) As the drilling fluid displacement increases, the annulus temperature of the wellbore above the mudline increases, and the temperature of the wellbore below the mudline decreases continuously; (3) As the density of the drilling fluid increases, the temperature at the wellhead decreases, and the temperature at the bottom of the well increases slightly; (4) The greater the rate of penetration of the well, the temperature at the upper part of the wellbore decreases, and the temperature at the bottom of the wellbore increases; Among them, the penetration rate has the most obvious effect on the annular temperature. The results are expected to be helpful to guide the drilling process of marine gas hydrate and offer some references.

Owing to the advantages of ultra-wide bandgap and rich material systems, gallium oxide (Ga2O3) has emerged as a highly viable semiconductor material for new researches. This article mainly focuses on the growth processes, material characteristics, and applications of Ga2O3. Compared with single crystals and the epitaxial growth of other wide-bandgap semiconductors, large-size and high-quality β-Ga2O3 single crystals can be efficiently grown with a low cost, making them highly competitive. Thanks to the availability of high-quality single crystals, epitaxial films, and rich material systems, high-performance semiconductor devices based on Ga2O3 go through a booming development in recent years. The defects and interfaces of Ga2O3 are comprehensively analyzed owing to their significant influence on practical applications. In this study, the two most common applications of Ga2O3 materials are introduced. The high breakdown electric field, high working temperature, and excellent Baliga's figure-of-merit of Ga2O3 represent an inspiring prospect for power electronic devices. In addition, the excellent absorption in deep-ultraviolet band provides new ideas for optoelectronic detectors and ensures the dramatic progress. Finally, the summary, challenges, and prospects of the Ga2O3 materials and devices are presented and discussed.

Constructing a heterojunction photocatalyst is a significant method to enhance photocatalytic activity because it can promote the separation of photogenerated carriers. Herein, amorphous/crystalline contact Bi2S3/Bi4O7 heterostructure was successfully synthesized by in-situ sulfidation of Bi4O7. The amorphous Bi2S3 is diffused on the surface of Bi4O7 rod, enhancing the visible light response and improving the transport of photogenerated carriers. Various characterizations confirm that the rapid separation of photogenerated carriers leads to increased photocatalytic performance. The optimized Bi2S3/Bi4O7 heterostructure photocatalyst (BiS-0.15) exhibits the highest Cr(VI) reduction (0.01350 min−1) and RhB oxidation (0.08011 min−1) activity, which is much higher than that of pure Bi4O7 and Bi2S3/Bi4O7 mixture under visible light irradiation. This work provides new insights into the construction of efficient novel photocatalysts.

Photocatalyst fabrication process plays the central role in photocatalytic hydrogen (H2) evolution reaction. Herein, we synthesize Na+ functionalized porous graphitic carbon nitride nanorods (Na-CNNR) via a facile one-pot calcination method. The morphology and size of Na-CNNR are controllable by changing the amount of sodium salt; both sodium salt and air are essential to the unique structure and oxygen doping. The obtained Na-CNNR contains abundant oxygen in the graphitic carbon nitride (CN) plane. The optimized Na20-CNNR (20 wt% Na2S2O3•5H2O to dicyanamide) photocatalyst exhibits a high surface area with enhanced visible light absorption. Besides, Na20-CNNR displays fast charge transfer and high carrier separation rate characterized by photoluminescence (PL) spectroscopy and electrochemical test. Through time-resolved transient absorption spectra analysis, the trapped unreactive electron accumulation can be highly restrained, favoring efficient active electron de-trapping and transfer. The optimized Na20-CNNR sample exhibits the highest photocatalytic H2 evolution rate of 7.46 mmol/h/g under visible light irradiation (>400 nm, 100 mW/cm2), which is up to 85 times that of the bare CN and 27 times that of Na+ doped graphitic carbon nitride nanoparticles (Na20–CNNP). Meanwhile, the cyclability tests indicate that Na20-CNNR displays robust stability over 24 h.

Acyl-CoA synthetase long-chain family member 4 (ACSL4) is an important isozyme for polyunsaturated fatty acids (PUFAs) metabolism that dictates ferroptosis sensitivity. The role of ACSL4 in the progression of ischemic stroke is unclear. Here, we found that ACSL4 expression was suppressed in the early phase of ischemic stroke and this suppression was induced by HIF-1α. Knockdown of ACSL4 protected mice against brain ischemia, whereas, forced overexpression of ACSL4 exacerbated ischemic brain injury. ACSL4 promoted neuronal death via enhancing lipid peroxidation, a marker of ferroptosis. Moreover, knockdown of ACSL4 inhibited proinflammatory cytokine production in microglia. These data identify ACSL4 as a novel regulator of neuronal death and neuroinflammation, and interventions of ACSL4 expression may provide a potential therapeutic target in ischemic stroke.

Low-cost, flexible and safe battery technology is the key to the widespread usage of wearable electronics, among which the aqueous Al ion battery with water-in-salt electrolyte is a promising candidate. In this work, a flexible aqueous Al ion battery is developed using cellulose paper as substrate. The water-in-salt electrolyte is stored inside the paper, while the electrodes are either printed or attached on the paper surface, leading to a lightweight and thin-film battery prototype. Currently, this battery can tolerate a charge and discharge rate as high as 4 A g−1 without losing its storage capacity. The charge voltage is around 2.2 V, while the discharge plateau of 1.6–1.8 V is among the highest in reported aqueous Al ion batteries, together with a high discharge specific capacity of ∼140 mA h g−1. However, due to the water electrolysis side reaction, the faradaic efficiency can only reach 85% with a cycle life of 250 due to the dry out of electrolyte. Benefited from using flexible materials and aqueous electrolyte, this paper-based Al ion battery can tolerate various deformations such as bending, rolling and even puncturing without losing its performance. When two single cells are connected in series, the battery pack can provide a charge voltage of 4.3 V and a discharge plateau as high as 3–3.6 V, which are very close to commercial Li ion batteries. Such a cheap, flexible and safe battery technology may be widely applied in low-cost and large-quantity applications, such as RFID tags, smart packages and wearable biosensors in the future.

In this paper, we present a high-order arbitrary Lagrangian Eulerian (ALE) method for compressible single-material flow on adaptive moving unstructured meshes. The discretization of system is implemented by Runge-Kutta Discontinuous Galerkin (RKDG) method. The vertex velocity is given by the approach of mesh movement from G. Chen et al. (2008) [8] . The new mesh can be automatically redistributed and concentrated on the regions with large gradient value of the variables. A HWENO reconstruction is used to eliminate false oscillations which maintains compactness of DG methods. In addition, we prove the property that the material derivatives of the Lagrangian basis functions are equal to zero with which the scheme is shown to satisfy the geometric conservation law (GCL). Furthermore, the scheme is conservative for mass, momentum and total energy. Numerical examples are presented to illustrate the good performance and high-order accuracy of the scheme.

High-quality CsPbBr3 thin films have been fabricated by pulse laser deposition (PLD) technique and severed as an interlayer for n-ZnO/p-GaN heterojunction ultraviolet (UV) photodetector. The self-powered photodetectors based on n-ZnO/CsPbBr3/p-GaN heterojunction exhibited a high peak responsivity of 44.53 mA/W and detectivity of 2.03✕1012 cm·Hz1/2W−1 under zero bias voltage, which has increased ∼30 and ∼178 times than that of the n-ZnO/p-GaN device, respectively. Meanwhile, the photodetector with excellent stable and reproducible characteristics were also demonstrated and the photoresponse time has been drastically shortened by inserting the CsPbBr3 interlayer. The key role of the CsPbBr3 interlayer, as a carrier transport layer, has been demonstrated by the energy-band diagram. The enhanced performances of n-ZnO/p-GaN heterojunction make them promising application in self-powered photodetectors.

Inspired by the mussel foot protein and chitosan-based macromolecular adhesives, a series of chitosan-graft-polypeptides were synthesized by ring-opening polymerization of three N-carboxyanhydrides (NCAs) - 3,4-dihydroxyphenylalanine-N-carboxyanhydride (DOPA-NCA), cysteine-NCA (Cys-NCA) and arginine-NCA (Arg-NCA) - using partial-NH2-protected chitosan as an initiator. These copolymers demonstrated good biodegradability and low cytotoxicity. The results of lap-shear adhesion test showed that the maximum lap-shear adhesion strength on the porcine skin and aluminum sheet were 195.97 ± 21.1 kPa and 3080 ± 320 kPa, respectively, and the maximum tensile adhesion strength on bone was 642.70 ± 61.1 kPa. The rat experiment in vivo showed that these copolymers exhibited good hemostatic performance and can promote the healing of skin wound and bone fracture. It is expected that thesecopolymeric adhesives will have broad applications in hemostasis and soft tissue adhesions.

s In this paper, the ethanol vapor deflagration with different fuel pool location and area were experimental studied in a reduced sized tunnel with a size of 3 m✕0.3 m✕0.25 m. There were two fuel pans were set in the tunnel, the first fuel pan with a diameter of 10 cm was fixed in the center of the tunnel, and this one was heated by a PID temperature control heater. The another one (with a diameter of 10 cm or 15 cm) was separately set at 25 cm, 50 cm, 75 cm, 100 cm, and 125 cm according to test conditions. The characteristics of deflagration flame propagation, flame structure and the pressure were analyzed. The study found that the complex liquid-gas two-phase coupling effect was showed during the deflagration progress in the tunnel that the combustible vapor required for the duration of deflagration was controlled by the vapor phase transition process of flammable liquid distributed in the tunnel. The flammable ethanol vapor is a necessary condition for explosion. On the contrary, the flame of explosion promotes the evaporation of ethanol liquid. When the area of the leak source is constant, the explosion pressure and the flame speed decrease as the distance from the leak source to the explosion source increases. When the position of the leak source in the tunnel is constant, the explosion pressure and the explosion flame speed increase as the area of the leak source increases. In particular, when the fuel pan is 25 cm from the center of the explosion source, the overpressure at a fuel pan with a diameter of 15 cm is nearly 2.6 times that at 10 cm, and the flame propagation speed is about 1.2 times.

On the basis of BODIPY platform, a terpyridyl-substituent BODIPY-Copper complex (Cu(II)-BTPY) was rationally designed and synthesized as a redox reaction fluorescent sensor for detecting HNO over reactive oxygen species (ROS) and reactive nitrogen species (RNS) with impressive selectivity in living cells under mild and neutral conditions. The BTPY exhibits relatively high fluorescence quantum efficiency as much as 34.8% and presents large stokes shift, about 62 nm. When a series of transition metal ions were exploited to investigate the fluorescence quench towards BTPY, copper ion (Cu2+) gave the optimal result. After the fluorescence of the probe being effectively quenched in the presence of Cu2+, it can be in turn recovered through the reduction of Cu2+ into Cu+ by HNO accompanying with a visually observable fluorescence response. Still, the sensing mechanism was evidently confirmed by EPR and ESI-MS measurement. In addition, the employment of BTPY for imaging dyes was also presented in vivo.

Exploring active catalyst materials for solar-driven photocatalytic water splitting into oxygen has proven extremely challenging, mostly due to poor oxygen-evolving efficiency originating from intrinsically sluggish oxygen evolution reaction (OER) kinetics. Ag3PO4 has been actively pursued as a promising photocatalyst for oxygen evolution from water-splitting. However, its low OER efficiency is a long standing problem. Both the construction of Z-scheme Ag3PO4-based composite photocatalytic systems and the optimization of surface morphology and interfacial contact in heterojunctions photocatalysts would be beneficial for boosting OER efficiency. Here we report on the fabrication of Ag3PO4/fish scale-like graphitic carbon nitride (g-C3N4) sheet composites with well-defined heterostructures and intimate interfacial contact driven by electrostatic assembly. The Ag3PO4/modified g-C3N4 composites photocatalyst reveals significantly enhanced oxygen-evolving activity under light-emitting diode (LED) illumination. Effective surface modification of g-C3N4, strong interfacial interactions between two semiconductors and tandem Z-scheme-type pathway for more efficient charge transfer synergistically accelerates the redox capability of Ag3PO4 for OER. This work may provide new insights into the design and construction of high-performance solar-driven Z-scheme photocatalytic water splitting systems.

Recently, the serious heavy haul railway tunnel fire that always resulted in the enlarger of the fire area have attracted much attention due to its great threat to people's life and property. As to this type of large area fire ascribed to multiple fuel source in tunnel, its burning always controlled by the ventilation, and it could be generally divided into three major regions: fuel-rich and hypoxic central zone, reaction zone, and burned out zone near the entrance due to the lack of the oxygen in the middle of the tunnel, however, the temperature distribution of this type fire in tunnel could not be reflected by the existing empirical models well. In order to predict the temperature distribution induced by the large area fire in tunnel well, an extended three-part model was proposed on the basis of the analysis of the special fire characteristic. And the fitting correlations for ceiling temperature of the continuous multiple fire sources were obtained based on a series of experiments. What’s more, the revised vertical temperature correlations based on the McCaffrey’s model were also obtained. It can be seen that the vertical temperature in the centerline of the tunnel remained nearly constant as the number of fire sources increases.

Photoelectrocatalytic (PEC) technique for hydrogen evolution from water splitting and pollutant degradation is one of the most sustainable and environmental approaches for wastewater treatment and energy regeneration. Herein, a porous graphitic carbon nitride (g-C3N4)/reduction graphene oxide (rGO) structure (CNG) is constructed via a solvothermal approach. By using a facile electrophoretic deposition method, CNG is deposited on nickel (Ni) foam with the formation of highly active CNG-Ni foam photoanode. rGO were utilized to load g-C3N4, and also acts as the bridge for accelerating the rate of electron transfer from g-C3N4 to Ni foam. The resulted photoanode exhibits an excellent photoelectrochemical performance for synergistic pollutant degradation and H2 evolution under visible light irradiation (λ > 420 nm). Such excellent PEC activity is attributed to the strong visible-light absorption and fast electron transmission of the as-obtained photoanode. The visible light-driven photocurrent value of the optimal photoanode can be well maintained up to 24 h, indicating its high stability during the PEC process. This work also shows significance for paving a facile route to fabricating highly active photoelectrodes for environmental and energy applications.

Panax ginseng is being used for medicinal treatment and health tonic for over 2000 years in orient countries. As transplanting is necessary during ginseng cultivation, selection of ginseng seedling is of economic importance for ginseng production. The objective of this study was to determine the effects of seedling size on post-planting performance, yield and ginsenoside content. Ginseng seedlings from two cultivars (‘Kangmei01’ and ‘Xinkaihe01’) were classified into three grades, and a field experiment was carried out to investigate seedling performance of different grades in 2013–2015 and 2014–2016. Larger size ginseng seedlings generally had higher stem height, stem diameter and leaf area for all growth seasons, but the differences were not significant between adjacent grades sometimes. Larger size ginseng seedlings also resulted in greater main root length, root diameter, single root weight, yield and seed number per plant at harvest. In contrast, smaller size seedlings had higher increase index of single root weight and yield as well as higher ginsenoside content in main root at harvest. Different grades of ginseng seedlings did not show difference in survival rate at each growth season and rootlet ginsenoside content at harvest. The results suggested that larger ginseng seedlings had greater aerial part and gained higher yield, while smaller ones showed higher relative growth rate and contained larger amounts of ginsenosides.

Hydrogel electrolyte is especially suitable for solid-state Al-air batteries targeted for various portable applications, which may, however, lead to continuous Al corrosion during battery standby. To tackle this issue, an ethanol gel electrolyte is developed for Al-air battery for the first time in this work, by using KOH as solute and polyethylene oxide as gelling agent. The ethanol gel is found to effectively inhibit Al corrosion compared with the water gel counterpart, leading to stable Al storage. When assembled into an Al-air battery, the ethanol gel electrolyte achieves a much improved discharge lifetime and specific capacity, which are 5.3 and 4.1 times of the water gel electrolyte at 0.1 mA cm−2, respectively. By studying the gel properties, it is found that a lower ethanol purity can improve the battery power output, but at the price of decreased discharge efficiency. On the contrary, a higher polymer concentration will decrease the power output, but can bring extra benefit to the discharge efficiency. As for the gel thickness, a moderate value of 1 mm is preferred to balance the power output and energy efficiency. Finally, to cater the increasing market of flexible electronics, a flexible Al-air battery is developed by impregnating the ethanol gel into a paper substrate, which can function normally even under serious deformation or damage.