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The BxN electrode could be used as a new lightweight Na-ion batteries anode with high capacity, cyclability, and desired rate performance.

Developing covalent organic frameworks (COFs) with good electrical conductivity is essential to widen their range of practical applications. Thermal annealing is known to be a facile approach for enhancing conductivity. However, at higher temperatures, most COFs undergo amorphization and/or thermal degradation because of the lack of linker rigidity and physicochemical stability. Here, we report the synthesis of a conductive benzoxazole-linked COF/carbon hybrid material (BCOF-600C) by simple thermal annealing. The fused-aromatic benzoxazole and biphenyl building units endow the resulting COF with excellent physicochemical stability against high temperatures and strong acids/bases. This allows heat treatment to further enhance electrical conductivity with minimal structural alteration. The robust crystalline structure with periodically incorporated nitrogen atoms allowed platinum (Pt) atoms to be atomically integrated into the channel walls of BCOF-600C. The resulting electrocatalyst with well-defined active sites exhibited superior catalytic performance toward hydrogen evolution in acidic media.

Na-ion batteries (SIBs) are emerging as a promising alternative to Li-ion batteries for large-scale energy storage in light of abundant Na resources and their low cost. Development of appropriate electrode materials that can conquer some critical issues such as low theoretical storage capacity and sluggish redox kinetics resulting from the larger radius of Na is urgently needed for their practical applications. In this work, boron-rich 2D B

Owing to lightweight, abundant reserves, low cost, and nontoxicity, B-based two-dimensional (2D) materials, e.g., borophene, exhibit great potential as new anode materials with higher energy density for Li-ion batteries (LIBs). However, exfoliation of borophene from the Ag substrate remains the most daunting challenge due to their strong interfacial interactions, significantly restricting its practical applications. In this study, through first-principles swarm-intelligence structure calculations, we have found several Boron-rich boron nitride BxN materials (x = 2, 3, 4, and 5) with increased stability and weakened interactions with the Ag(111) substrate compared with δ6-borophene. A high cohesive energy and superior dynamical, thermodynamic, and mechanical stability provide strong feasibility for their experimental synthesis. The obtained BxN materials exhibit a high mechanical strength (94-226 N/m) and low interfacial bonding with the Ag substrate, from -0.043 to -0.054 eV A-2, significantly smaller than that of δ6-borophene. Among them, B3N and B5N exhibit not only a remarkably high storage capacity of 1805-3153 mAh/g but also a low barrier energy and open-circuit voltage. Moreover, B2N showed a cross-sheet motion with a low barrier of 0.24 eV, which is unique compared with the in-plane diffusion in most other 2D electrode materials restricted by their quasi-flat geometry. BxN also exhibits excellent cyclability with improved metallic conductivity upon Li-ion intercalation, showing great potential in LIB applications. This study opens up a new avenue to explore B-rich 2D electrode materials in energy applications and provide instructive insights into borophene functionalization and exfoliation.

Powder densification for specified shaped metal-organic frameworks (MOFs) is desirable for most applications. The obtainment of such properties is challenging, one of which is the rapid crystal-to-amorphous transition (framework collapse) of MOFs under pressure. Herein, we found that the residual guests of the MOF-5 synthesis process could form binding groups based on the hydrogen-bonding networks of water. The improved processability and ease of compression, which did not promote rapid structure collapse, can be achieved in the guest-loaded MOF-5. Correspondingly, enhanced volumetric specific surface area and methane uptake of MOF-5 were obtained. This work focuses on a commonly neglected but positive function of the residual guests in MOFs, besides supporting the framework. MOFs loaded with multiple types of guests show attractive mechanical properties via guest-guest and guest-host interactions for powder densification, highlighting their commercial applications.

Ultra-low wear or non-wear of moving parts is highly desirable because wear limits the service life and reliability of components, particularly under high temperatures. In this study, VN/Ag composites were prepared using vacuum hot-pressing sintering, and their microstructure and high-temperature tribological behaviour were studied. The results demonstrated that the tribological properties of VN ceramics remarkably improved because of metallic Ag. In particular, negative wear was detected in the VN/Ag composites at 700 °C. During the high-temperature tribology process, the evolution of Ag, V2O5, Ag3VO4, and AgVO3 caused by Ag and VN on the worn surface played a significant role in lubrication. In addition, the cell volumes of AgVO3 and Ag3VO4, which were produced via the expansive tribochemical reaction, were 75% and 103% larger than the sum of the cell volumes of VN and Ag. The cell volume expansion compensated for the mechanical damage caused by the wear, possessed an excellent role in wear reduction, and thus contributed to the improvement of high-temperature lubricating materials with high reliability and long service lives.

Flexible metal–organic framework (MOF) materials have the ability to perform stimulated sudden volume contractions, and thus attract increasing attention for use in potential applications such as: actuators or sensors. Here, the structural transition of MIL-53(Cr) loaded with a high concentration of CH3OH (CH3OH) guest molecules, which cause internal pressure due to guest–guest interactions, was investigated. The pressure triggering the structural transition can be enhanced by high guest molecule loadings (1 CH3OH per unit cell (UC): 5 MPa, empty: 53 MPa, 7 CH3OH per UC: 90 MPa, and 8 CH3OH per UC: 280 MPa). The asymmetrical and small distortion of the organic–inorganic connections are the main microscopic characteristic of the structural transition of MIL-53(Cr) with a high CH3OH loading. The external pressure and the internal pressure, instead of the adsorption of the guest molecules, became dominant in the structural transition of MIL-53(Cr). Current studies showed that the high-pressure response of the flexible MOF structure may broaden the acceptable pressure range in future actuator or sensor applications.

Objective The aim of the present study is to explore the frequency of small intestinal bacterial overgrowth (SIBO) and orocecal transit time (OCTT) in patients with nonalcoholic fatty liver disease (NAFLD). Patients and methods 103 patients with NAFLD and 49 healthy controls were enrolled. Clinical indicators such as BMI, liver function, blood lipids, homeostasis model assessment-insulin resistance (HOMA-IR), serum endotoxin of NAFLD patients were collected and examined. FibroTouch was used to detect the controlled attenuation parameter (CAP) and liver stiffness measurement (LSM). SIBO and OCTT were measured by the lactulose hydrogen breath test. Results The incidence of SIBO in NAFLD patients (58.3%) was significantly higher than that in healthy controls (26.5%). The level of serum endotoxin in NAFLD patients was higher than that in healthy controls. The levels of CAP, LSM, serum endotoxin, alanine transaminase, asperate aminotransferase and HOMA-IR in SBIO-positive NAFLD patients were higher than those in SIBO-negative patients. There was no significant difference in glutamyl transpeptidase triglyceride, low density lipoprotein and BMI between the two groups. OCTT in NAFLD patients was longer than that in healthy controls. It was also observed that OCTT in SIBO-positive NAFLD patients was significantly delayed compared with SIBO-negative NAFLD patients. Conclusions Patients with NAFLD exhibit the increased incidence rate of SIBO and prolonged OCTT; SIBO in NAFLD patients maybe a contributing factor to the elevated transaminase, hepatic steatosis, progression of liver fibrosis and prolonged OCTT.

The properties of the porous ceramics are known not only related to the pore-solid composite model, but also have a significant grain-size effect. In this study, a phase field simulation is carried out to study the effect of different micropores on the grain growth kinetics of porous ceramics, and results indicate that the average grain size and distribution are highly influenced by the topological shape of the second-phase. The efficiency of the grain boundary migration is determined by the pinning forces applied in the interaction of the grains and pores. The pining forces are calculated based on Zener Theory, and results indicate that the maximum pinning force is highly dependent on the second-phase shape, and the contacting mode between the grain boundaries and second-phase pores is the determining factor of the grain boundary migration in porous materials.

Background Nerve growth factor (NGF) and enteric glial cells (EGCs) are associated with visceral hypersensitivity and gastrointestinal motility disorder, which may represent the pathogenesis of functional dyspepsia (FD). This study aimed to investigate the expression of NGF, its high affinity receptor tropomyosin receptor kinase A (TrkA) and the EGC activation marker glial fibrillary acidic protein (GFAP) in the gastric mucosa of patients with FD and the association of these proteins with dyspeptic symptoms. Methods Gastric mucosal biopsies taken from 27 FD patients (9 epigastric pain syndrome (EPS) patients, 7 postprandial distress syndrome (PDS) patients and 11 EPS overlap PDS patients) and 26 control subjects were used for analysis. The expression of NGF, TrkA and GFAP was examined, and the association of these proteins with dyspeptic symptoms, including epigastric pain, postprandial fullness, early satiation and epigastric burning, was analysed. Results The expression levels of NGF, TrkA, and GFAP in the gastric mucosa were significantly higher in the EPS group, the PDS group, and the EPS overlap PDS group than in the healthy control group. There was no significant difference between the FD subgroups. TrkA colocalized with GFAP, which indicated that TrkA was localized to EGCs, and the expression of TrkA in EGCs was significantly higher in the FD group than in the control group. Changes in the expression of NGF, TrkA, and GFAP were positively correlated with epigastric pain, postprandial fullness and early satiation but had no significant relationship with epigastric burning. Conclusions The increased expression of gastric NGF, TrkA and GFAP might be involved in FD pathophysiology and symptom perception.

Herein, we used first-principles calculations and the particle swarm optimization technique to predict a highly incompressible W0.5Al0.5N phase with the space group R3¯m(166). Our results reveal that this phase, which was characterized by a negative formation enthalpy, is thermodynamically and dynamically stable, as revealed by the absence of imaginary modes in the phonon spectra. Furthermore, its energetic stability at a pressure of 15 GPa indicates a feasible strategy for experimental synthesis. The high performance stems from the optimized octahedral coordination between N and W/Al. Additionally, the good elastic parameters with BH of 310 GPa, GH of 206 GPa, and HV of 27 GPa confirm that it has preferable mechanical behaviors among the various W0.5Al0.5N phases and is even superior to those of the experimentally well-established NaCl-type phase. Based on the recently developed strain–stress method, it is shown that the ideal indentation strength of R3¯m(166) is about 32.7 GPa in the (1 1¯ 0) [0 0 1] direction, which is in excellent agreement with estimated HV. Therefore, our findings open the possibility for producing a new class of transition metal aluminum nitrides that have a broad range of applications.

Polymers with excellent comprehensive performance toward enhanced stability and mechanical strength are attractive for matrix loading of tunable porous and inherently brittle metal−organic frameworks (MOFs). Polyethersulfone (PES) with high mechanical strength (elastic modulus = ~2.6 GPa) is one of the best polymeric materials widely applied in gas and liquid separations but hindered by its ability to adhere to MOFs surface. The combination of the interface width, porosity, atomic density, and hydrogen bonding number and strength strongly influences MOFs/PES compatibility. ZIF-8 is one of the most frequently investigated MOFs, and exhibits excellent interface compatibility with PES, which is confirmed by both computational and experimental analyses. The desired porosity and adsorption properties of ZIF-8 are retained in ZIF-8/PES composites. This study sheds light on the theoretical understanding and characterization of hybrid material systems with diverse differences between brittle MOFs and stiff polymers.

To date, compared with that of lithium oxygen batteries, the operation of lithium air batteries is still a great challenge due to the highly deteriorated cathode performances in air, including worse discharge capacities and OER/ORR dynamics. Herein, we propose hydroxylated carbon black as an improved deposition support, which not only functions as a conductive agent, but also improves the morphology of the discharge products. These improvements can significantly enhance the discharge properties and chargeability of the gas cathode, particularly in simulated air or ambient air. For example, the hydroxylated carbon black doubles the energy output of the air cathode in ambient air. It is believed that increased defects and hydroxyls on the hydroxylated carbon surface might play an important role. By the first principle calculation, it is revealed that a strong affinity between the hydroxyls and Li2O2 occurs, and this facilitates the nucleation of Li2O2. It is believed that the promoted nucleation can restrain the growth of the discharge products due to the competitive relationship between nucleation and growth of new phase in chemical reactions. Finally, smaller Li2O2 nanosheets formed on the hydroxylated carbon cathode instead of the dense discharge product layer, avoid the block of the porous cathode, thus benefiting the electrochemical performances. These results show that besides developing better catalysts, hydroxylation of carbon matrix is also an effective strategy to enhance the electrochemical performances of the lithium air battery.

The phase separation in Fe-40%atCr-5at%Mo alloy is investigated by implementing a model based on Cahn–Hilliard equation. Solute diffusion of three elements are simulated and discussed in the 2D condition. A statistical analysis is performed to investigate the microstructural change during the spinodal decomposition. A droplet-matrix pattern is achieved with the Cr rich and Mo rich droplets embedded in Fe rich matrix, and the Cr rich and Mo rich droplets have the approximatively same shape and distribution. The number and average size of Cr rich and Mo rich droplets keep changing with a decreased change rate, and the size distribution of droplets has a significant change with time. The concentration distributions of Cr and Mo are different and form core-shell structures in the Fe rich matrix. Temperature is an active promotion factor to the phase separation in Fe-40%atCr-5at%Mo alloy. Simulated diffusion behavior of Mo and Cr in Fe–Cr–Mo ternary alloys is in good agreement with that predicted by the theory.

The microstructure evolution during solidification of pure Aluminum metal with gas bubble nucleation and growth is modeled and simulated by the phase-field method. Interface microstructure formation in the presence of gas bubble is simulated to investigate the interaction between gas bubble and microstructural evolution, and also a pressure correction equation is implemented to study the effect of pressure difference between the bubbles and melts. Results indicate that pressure difference between gas bubble and the liquid melt can significantly affect the gas atoms diffusion near the gas–liquid interface, which will lead to the bubble growth velocity change. These simulation results are in agreement with experimental observations.

A promising lead-free ferroelectric material, Bi0.5Na0.5TiO3 (BNT), was recently proposed as an oxide ion conductor. In a survey of BNT perovskite-structured oxides that exhibit ionic conductive grain, it was found to be highly sensitive to stoichiometry and the synthesis processes. The conduction mechanism and defect properties of these BNT therefore could be greatly influenced. Herein, we show composites made by a ferroelectric matrix of acceptor-doped BNT with a slight amount of Ag2O in which the defect and transport properties could be tailored through different sintering atmospheres. The bulk conductivity increased dramatically by ∼2800 times to 1.36 mS cm−1 at 502 °C.

Based on nonsubsampled contourlet transform (NSCT) and modified pulse coupled neural network (MPCNN), the paper proposes an effective method of image fusion. Firstly, the paper decomposes the source image into the low-frequency components and high-frequency components using NSCT, and then processes the low-frequency components by regional statistical fusion rules. For high-frequency components, the paper calculates the spatial frequency (SF), which is input into MPCNN model to get relevant coefficients according to the fire-mapping image of MPCNN. At last, the paper restructures the final image by inverse transformation of low-frequency and high-frequency components. Compared with the wavelet transformation (WT) and the traditional NSCT algorithm, experimental results indicate that the method proposed in this paper achieves an improvement both in human visual perception and objective evaluation. It indicates that the method is effective, practical and good performance.Based on nonsubsampled contourlet transform (NSCT) and modified pulse coupled neural network (MPCNN), the paper proposes an effective method of image fusion. Firstly, the paper decomposes the source image into the low-frequency components and high-frequency components using NSCT, and then processes the low-frequency components by regional statistical fusion rules. For high-frequency components, the paper calculates the spatial frequency (SF), which is input into MPCNN model to get relevant coefficients according to the fire-mapping image of MPCNN. At last, the paper restructures the final image by inverse transformation of low-frequency and high-frequency components. Compared with the wavelet transformation (WT) and the traditional NSCT algorithm, experimental results indicate that the method proposed in this paper achieves an improvement both in human visual perception and objective evaluation. It indicates that the method is effective, practical and good performance.

Bi4Ti3O[Formula: see text]/Bi2S3 heterostructures with enhanced visible light photocatalytic activity are successfully synthesized via a two-step synthesis route based on a sol–gel hydrothermal method and a subsequent hydrothermal-ion exchange reaction technique. The structures, composition, morphologies and light absorption capability of Bi4Ti3O[Formula: see text]/Bi2S3 heterostructures are verified by XRD, XPS, SEM, TEM and UV-Vis diffuse reflectance spectra, respectively. Results indicated that Bi2S3 nanorods are grown on the surface of the spherical structure assembled by criss-cross nanosheets of Bi4Ti3O[Formula: see text] after ion exchange reaction. The photocatalytic tests reveal that the Bi4Ti3O[Formula: see text]/Bi2S3 heterostructures showed much higher photocatalytic activity than pure Bi4Ti3O[Formula: see text] or Bi2S3. The tight interconnection between the two semiconductors will facilitate the photoinduced carriers’ separation. Owing to the easy preparation and excellent property, the obtained Bi4Ti3O[Formula: see text]/Bi2S3 heterostructures may be promising photocatalysts for practical application.

RE site ionic radius has a critical influence on the properties of double perovskite oxide Ba2RENbO6. In this paper, the electronic structures and elastic properties of Ba2RENbO6 (RE = Ho, Er, Yb) have been calculated by using the plane-wave pseudopotential density functional theory, and the effect of the different RE site ions on the structures and properties of Ba2RENbO6 is discussed. Results indicate that Ba2RENbO6 (RE = Ho, Er, Yb) are all direct bandgap semiconductors with a bandgap of 0.95 eV, 1.26 eV and 2.36 eV, respectively. With the decrease of the RE site ionic radius of Ba2RENbO6 (RE = Ho, Er, Yb), RE–O and Nb–O covalent bonds are enhanced, and the elastic constants ([Formula: see text], [Formula: see text], [Formula: see text]), elastic modulus ([Formula: see text], [Formula: see text], [Formula: see text]), [Formula: see text], Poisson’s ratio ([Formula: see text]), the Debye temperature [Formula: see text], Gruneisen parameters [Formula: see text] all show a trend of increase. The elastic and thermodynamic properties are all improved with the decreasing radius of RE site ion.