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Carbon nanotubes are a new type of material with excellent properties, and their incorporation into cementitious materials can improve the microstructure and durability of the material. This paper reviews the research progress on the effect of nucleation, filling and bridging properties of carbon nanotubes on the microstructure and carbonation resistance of cementitious materials, and discusses the mechanism of the effect of the doping amount, dispersion method and length-to-diameter ratio of carbon nanotubes on the carbonation reaction of cementitious materials. The analysis shows that carbon nanotubes promote the hydration of cement by nucleation, increase the hydration product Ca(OH)2, increase the alkalinity of the matrix and slow down the carbonisation, and optimise the pore structure of the material and the compactness of the interfacial transition zone by combining the filling and bridging effects, inhibit the formation of microcracks and prevent the infiltration of CO2, thus optimising the microstructure of cement-based materials and enhancing their anti-carbonisation properties. Finally, the problems of the current research are analyzed and the prospects of its research are given. [ABSTRACT FROM AUTHOR]

Tn this paper, Co3O4 / Fe3O4 composite nanomaterials were prepared by sol-gel reaction and high temperature calcination method. By adjusting the concentration of Co(NO3)2 • 6H2O and Fe(NO3)3 • 9H2O in precursor, the content of two components in C03()i/FesOi can be adjusted, and the grain size of CO3O4/Fe3O4 can be changed by changing calcination temperature. The phase, morphology, and structure of Cog (人./F& (人 composites were characterized by XRD, SEM, XPS and N, adsorption desorption measurement. The results of thermal catalysis showed that with the increase of the molar ratio of Fe3O4 to Co3O4, the thermal catalytic activity of Co3O4 / Fe3O4 composites for isopropanol (TP A) degradation was continuously enhanced. When the molar ratio of Fe3O4 to Co3O4 was 0.5:1 and the calcination temperature reach 500°C, the composites showed the highest thermal catalytic activity and better stability. The Co3O4 / Fes Oi heterojunction could promote the separation of electrons and holes in the thermal catalytic redox reaction, and generated • O2?--radicals on the material surface, which could further oxidize with TP A, and finally realized the efficient degradation of TPA. [ABSTRACT FROM AUTHOR]

Electrochemical water splitting is one of the ways to produce clean energy. However, oxygen evolution reaction (OER), an important half-reaction involving complex four-electron transfer, significantly reduces the overall water splitting efficiesncy. Tn this paper, by means of interface engineering. Ni(OH)2/CeO2 hybrid particles were modified with Nis nanosheet arrays grown in situ on nickel foam (NF) by electrodeposition, so as to successfully prepare an efficient and stable OER composite electrode. Scanning electron microscopy (SEM), X-ray diffraction (XRT)) and X-ray photoelectron spectroscopy (XPS) were used to characterize and analyze the microstructure, phase composition and surface element valence of the electrode materials. Tn the 1.0 M KOH electrolyte, the overpotential required to drive the current density of 100 mA/cm² is only 330 mV, the Tafel slope is 150.7 mV/dec, and the durability can be maintained for at least 25 h. The excellent electrocatalytic performance is due to the synergistic catalytic effect of Ni(0H)2/CeO2 particles and Nis nanoarray and the promotion of Ce1+ cations on the formation of OER active components. This study confirms that rare earth compounds have certain potential in modifying sulfide catalysts and can be widely used in the field of energy catalysis. [ABSTRACT FROM AUTHOR]

Electrocatalytic nitrogen reduction (ENRR) under mild conditions is an environmentally friendly nitrogen fixation strategy, which is expected to replace the Haber - Bosch process with harsh conditions, high energy consumption and environmental pollution. The development of high-performance electrocatalytic catalysts is the key to solve the problems of the difficulty in dissociation of the N=N triple bond and the difficulty in adsorption of nitrogen. Tn this paper, we prepared non-noble metal nanoporous FeNbMoP alloy catalyst with self-supporting structure by electrochemical dealloying method and applied it to catalyze ENRR. The addition of nano-porous structure and non-metal lie element and transition metal Nb element improves the reaction activity. and the catalyst after optimization has the ammonia yield of 23.3/.tg h-1 cm-2. This study provides a new direction for the subsequent synthesis of high-performance ENRR catalysts. [ABSTRACT FROM AUTHOR]

Manganese oxides have attracted much attention due to their excellent structural diversity and novel physical and chemical properties. The common manganese oxides MnO2, Mn2O3, MnsO..] and MnO have broad application prospects in catalysis, magnetic applications, energy storage, and other fields. The reduction of material dimension might lead to the improvement of performance. Therefore, a lot of efforts have been made in the preparation of manganese oxide nanowires, especially in the hydrothermal synthesis of manganese oxide nano wires with different crystal structures. Tn this paper, the effects of growth parameters (reaction temperature, reaction time, pH value, etc.) on the structure and morphology of manganese oxide nanowires prepared in the hydrothermal preparation process were summarized, in order to provide a reference for the hydrothermal growth of manganese oxide nanowires with controllable size and good performance. [ABSTRACT FROM AUTHOR]

The traditional NiTi alloy has been widely used in many fields due to its superelasticity, shape memory effect and excellent bio compatibility. For example, it has been prepared into orthodontic arch wire and vascular stent in the biomedical field. However, biomedical equipment needs precision and miniaturization, and the traditional NiTi alloy has been unable to keep up with the development. The nanocrystalline NiTi alloy after severe plastic deformation has better tensile, compressive strength, plasticity and fatigue properties than the traditional coarse and ultra-fine grained NiTi alloy. Tt is expected to expand the scope of application in the biomedical field. Nanocrystalline NiTi alloy can be used in the manufacture of new medical devices and orthopedic bio--materials. The combination of NiTiAg with Ag not only has excellent mechanical properties, but also has antibacterial effect. W-NiTi composite material is formed by combining with W nanowire/belt to improve the radiation opacity and make the positioning and deployment of instruments and implants in the human body easier. Tn recent years, there is also a new surface modification technology, ultrasonic nanocrystalline surface modification, which produces nanocrystalline on the surface of NiTi alloy to improve fatigue and corrosion resistance. This paper mainly introduces the application of existing NiTi alloys and the application prospect of nanocrystalline NiTi alloys in biomedical field. [ABSTRACT FROM AUTHOR]

Graphite carbon nitride (g--CC3N3) has attracted wide attention due to its advantages of low cost, easy preparation, high chemical and thermal stability, and suitable band gap. However, g-CC3N3 prepared by traditional thermal polymerization method has the disadvantages of small surface area, easy aggregation and low photo catalytic activity. Tn this paper, carbon nitride nanosheets were prepared by a simple thermal oxidation method and tested through photoelectro chemi cal measurements. The effect of external bias on the direction of photocurrent was investigated by photochemical tests, and the reaction mechanism of electrode interface under photoelectric induction was discussed. The structure, morphology and optical properties of the samples were characterized by X-ray diffractometer (XRD), electron microscopy (SEM/HRTEM), X-ray photoelectron spectroscopy (XPS), photoluminescence spectroscopy (PL) and UV-Vis DRS. The effect of thermal oxidation on the structure and photoelectrochemical performance of carbon nitride in air atmosphere was systematically studied. The BET results showed that the specific surface area of the carbon nitride nanosheets (160.6 m²/g) was one order of maC3N3tude higher than that of the bulk g-CC3N3 (12.5 m²/g). Tn addition, the photocurrent density of g-CC3N3 with two-dimensional nanosheet structure is twice as high as that of the bulk g-CC3N3 under UV-vis light, and a lower OER potential was obtained. [ABSTRACT FROM AUTHOR]

With the increasing application of nanocellulose materials, it is found that some nanocellulose composites can improve its overall performance and have low cost and wide sources. Nanocellulose materials such as subnanometer cellulose crystal (CNC), microcrystalline cellulose (MC'C), nanocellulose (NFC), bacterial nanocellulose (BNC) and other materials are prepared by different methods. With the help of mechanical stretching, spinning, electric field, magnetic field and other methods, it is used to prepare directional alignment with high orientation and high performance. Nanocellulose materials with high strength and stiffness are used in textile industry, medical industry, optical devices and other fields. Tn this paper, these methods and materials are briefly discussed and the application characteristics of materials and methods are summarized. [ABSTRACT FROM AUTHOR]

Boron nitride（BN） ceramics have excellent properties such as high aspect ratio, high temperature resistance, high thermal conductivity and electrical insulation, widely used in electronic information, aerospace, metallurgy, machinery and other fields. 3D printing technology has low cost and time-saving compared with traditional processing methods, and is an important molding technology for the preparation of ceramic parts with complex three-dimensional structure. To this end, in this paper, based on the self-developed pneumatic new direct-write 3D printing material forming platform, ceramic slurries with different BN contents were prepared using BN and polyvinyl alcohol（PVA） as raw materials and binder, and ceramic preforms with different 3D structures were designed and prepared using the layer-by-layer stacking principle. By changing the rheological properties of the slurries, the BN 2D nanosheets were realized in the printing process under the shear. By changing the rheological properties of the slurry, the orientation of BN 2D nanosheets under the action of shear force was achieved during the printing process, and ceramic materials with high interplanar thermal conductivity were obtained. The effect of BN content on the molding quality of the ceramic parts was investigated, and the structure and microscopic morphology of the printed ceramic materials were characterized by XRD and SEM. The results show that the BN/PVA 85 slurry has good shear thinning and viscoelastic properties, and the yield stress in the linear viscoelastic region reaches 240 Pa, which is suitable for direct-writing 3D printing technology. the increased horizontal orientation of BN inside the part contributes to the enhanced interfacial thermal conductivity of the ceramic material, where the interfacial thermal conductivity of the BN/PVA 85 ceramic part is about 4.3 W/（m·K）. [ABSTRACT FROM AUTHOR]

Two-dimensional materials exhibit immense latent capacity in many domain with excellent performance, and monolayer MoSi2N4 materials have non-magnetic semiconductors and good stability. In this paper, first principles calculations based on density functional theory are used to study the photoelectric properties of intrinsic two-dimensional MoSi2N4 in nitrogen, silicon and molybdenum vacancies. The results show that compared with the intrinsic two-dimensional MoSi2N4, the band gap of the defective structure of the outer nitrogen and molybdenum atoms is greatly reduced, while the band gap of the inner nitrogen and silicon atomic defect structures is 0.781 eV and 0.736 eV, respectively. Moreover, the inner nitrogen defect changes the conduction type of two-dimensional MoSi2N4 from the original P-type to N-type semiconductor. Optical properties: Each defect structure causes different degrees of redshift in 2D MoSi2N4. Two-dimensional MoSi2N4 has excellent material properties, and the study of optoelectronic properties is of great significance for the new generation of optoelectronic devices.  [ABSTRACT FROM AUTHOR]

Polyimide（PI） material has become a hot precursor for the preparation of graphite cooling film in recent years because of its six-membered ring molecular structure and high carbon content. As a transition metal element, nickel is often used as the substrate for graphene catalytic growth. Doping nickel in the polyimide substrate can effectively improve its carbonization and graphitization degree and improve its thermal conductivity. However, pure nickel metal particles will deposit in the precursor of PI, polyamide acid（PAA）, which makes it difficult to disperse uniformly. In this work, the PI composite film was prepared by adding a metal complex soluble in organic solvent, nickel acetylacetone（Ni（acac）2）, into the PI matrix and graphitized at 2 700 ℃ to obtain a graphite film. The nickel obtained from the decomposition of Ni（acac）2 at high temperature can promote the carbonization of polyimide, and its solubility in organic solvent also significantly improves the dispersion of nickel in the PI matrix. Finally, the polyimide carbon film with a flat surface was prepared, and its thermal conductivity can reach 782 W/（m·K）, which is 30 times higher than that of the carbon film prepared by pure PI. The purpose of this paper is to analyze the carbonization process of polyimide catalyzed by metal complex Ni（acac）2 and the final carbon film structure, and explore the possibility of finally preparing high thermal conductivity graphite film.  [ABSTRACT FROM AUTHOR]

Traditional industrial ammonia production mainly comes from the Haber-Bosch method operated under high temperature and pressure, which requires high energy consumption and brings about large pollution. With electric energy as energy source and water as proton/electron source, nitrogen could be reduced to ammonia via the synergistic effect of voltage and catalyst. The electrocatalysis ammonia technology has gradually developed into one of the effective ways in ammonia synthesis. The key to the electrocatalytic ammonia synthesis technology is the design of catalysts and optimization of reaction systems. The reasonably design of high-efficiency electrocatalysts is considered as important approach to optimize the production kinetics and Faradaic efficiency. Here, the paper describes the primary classifications and research progress of electrocatalysts, which mainly include noble metal, transition metal, single-atom and non-precious metals. Then, the development of ammonia synthesis technology and reaction mechanism during the electrocatalytic ammonia production are elaborated. Moreover, the strategies for improving the activity in electrocatalytic ammonia production are reviewed, including surface morphology optimization, crystal defect engineering, composite material composition, phase interface, addition of additives, etc. Finally, the issues and challenges as well as development trends in the future are prospected. [ABSTRACT FROM AUTHOR]

Photocatalytic technology is an effective way to solve the two major problems of environmental problems and energy crisis. The development of efficient photocatalysts has become a research hotspot in this field. As new type of carbon nanomaterial, Carbon quantum dots（CQDs） have garnered much attention in the field of photocatalysis because of their unique up-conversion luminescence and excellent photogenerated electron transfer properties. In this paper, the mechanism of photocatalytic degradation of pollutants and the properties of carbon quantum dots was introduced, the research progress of photocatalytic degradation of organic pollutants in water by carbon quantum dots was reviewed with emphasis, followed by an outlook on their future and potential development. [ABSTRACT FROM AUTHOR]

Pollution of water resources is seriously endangering human health. Bismuth-based photocatalytic materials also show great potential in controlling organic pollution, with the advantages of green, efficient, clean and low cost. This paper briefly introduces the research progress of various bismuth-based photocatalytic materials in the degradation of organic wastewater, summarizes the modification methods of various bismuth-based photocatalysts and the degradation effects of various organic pollutants, and analyzes the factors affecting the efficiency of bismuth-based photocatalytic materials in the degradation of organic compounds in water. The future development of photocatalysis in the degradation of organic wastewater was also explored, and several proposals for the development of bismuth-based photocatalysis materials were presented. [ABSTRACT FROM AUTHOR]

In this paper, the effect of grain anisotropy on the electrochemical performance of anatase TiO2 was studied, which is significant for the improvement of supercapacitor material performance. Using hydrothermal synthesis, HF and H2SO4 were used as different acid morphology inducers, and tetrabutyl titanate was used as titanium source to prepare TiO2 in the form of platy and spherical microcrystals, which exposed different crystal faces. X-ray diffraction（XRD）, scanning electron microscopy（SEM） and transmission electron microscopy（TEM） confirmed that the crystal faces exposed by platyt TiO2 were highly active {001} planes, while the crystal faces exposed by spherical TiO2 were random. X-ray photoelectron spectroscopy（XPS） and specific surface and porosity analysis（BET） and corresponding electrochemical performance tests were used: the results showed that the specific surface area of platy TiO2（112.76 m~2/g） was 2.41 times that of spherical TiO2（46.88 m~2/g）, and the specific capacitance of platy TiO2 supercapacitor（174.0 F/g） is a spherical TiO2 supercapacitor specific capacitance（67.0 F/g）, while platy TiO2 supercapacitors exhibit higher cycle stability than spherical TiO2 supercapacitors. The excellent performance of platy TiO2 is mainly attributed to the high specific area and exposed highly active {001} crystal planes. [ABSTRACT FROM AUTHOR]

3D printing technology has been significantly developed in the construction field, and in order to address the concrete 3D printing industry to achieve sustainable development, this paper analyzes the causes of deterioration by conducting freezing resistance studies on 3D printed specimens and cast specimens with 0%, 50%, and 100% recycled coarse aggregate（RCA） substitution, combined with electron microscopy scans of the transition zone at the interface of 3D printed recycled coarse aggregate concrete（3DPRAC）. The results showed that the incorporation of RCA in the first 200 freeze-thaw cycles did not significantly reduce the mass and dynamic modulus of 3D printed concrete; after 600 freeze-thaw cycles the 3D printed recycled concrete with 100% RCA incorporation performed better than that with 50% RCA incorporation in the freeze-thaw cycles. Based on the construction characteristics of 3D printed recycled concrete stacked layer by layer, a 3DPRAC pore area concentration distribution model was proposed to reveal the 3DPRAC freeze-thaw damage deterioration mechanism. The established freeze-thaw damage model can better reflect the change pattern of 3DPRAC freeze-resistance performance. [ABSTRACT FROM AUTHOR]

Fe2O3 is considered to be a promising negative material for aqueous supercapacitors due to its advantages of low cost, non-toxicity, rich sources and environmental friendliness. However, it also suffers from the disadvantages of low conductivity, unsatisfactory cycling and rate performance. In this paper, N, S codoped-Fe2O3 was prepared on carbon fiber paper (CFP) by a hydrothermal method followed calcination process in the presence of thiourea under ambient atmosphere. The results demonstrated that calcination in thiourea didn't change the phase of Fe2O3, but changed its morphology from interconnected structure composed of nanowires to a dense film with porous structure. Due to the improved conductivity and the increased reaction active sites, N, S-Fe2O3 not only showed high specific capacitance (473.2 mF/cm², 2 mA/cm²), superior rate performance (85.5%, 2-20 mA/cm²) and good cycling stability (96%, 15 mA/cm², 10 000 cycles), but also exhibited higher electrochemical reaction reversibility and coulomb efficiency. Finally, asymmetric supercapacitors were assembled employing N, S-Fe2O3 and commercial activated carbon as negative and positive electrode, respectively, and the volume specific capacitance was 2.1 F/cm³(1 mA/cm²). By connecting two assembled supercapacitors in series, a series of LED lights (rated voltage of 3 V) could be successfully lit up, demonstrating its practical applications. [ABSTRACT FROM AUTHOR]

The use of green renewable cellulose nanocrystals (CNCs) with the ability to self-assemble photonic structures to construct flexible functional materials can provide rich visual information, reduce the cost and reduce the harm of non-degradable materials. However, due to the lack of effective soft energy consumption phase in the system, the photonic materials based on CNCs have shortcomings such as mechanical fragility and lack of dynamic optical response, which bring certain challenges to their functional expansion and application. Thus, according to the structural characteristics of CNCs, this paper introduces in detail the preparation methods and influencing factors of the current CNCs photonic membrane, and then summarizes the various synthesis and regulation strategies of the current CNCs photonic membrane from mechanical rigidity to mechanical flexibility and machine color responsiveness. At the same time, the promising application directions and future challenges of CNCs flexible functional photonic materials are emphasized in this paper. [ABSTRACT FROM AUTHOR]

BaTiO3 crystals have been widely used in the field of dielectric and piezoelectric components, but BaTiO3 has multiple phase transition temperatures, especially at room temperature, which will seriously damage the crystal quality. In order to improve the properties of BaTiO3, doping BaTiO3 crystals is considered. In this paper, based on first-principle calculation, the electronic structure and optical properties of BaTiO3 doped with different Ca contents, namely Ba1-xCaxTiO3 (x=0, 0.125, 0.25, 0.5), were calculated. It is found that BaTiO3 is a direct band gap semiconductor in terms of electronic structure, and its band gap width is 1.74 eV. Doping Ca leads to an increase in the band gap of BaTiO3. The density of states of BaTiO3 doped with Ca is larger than that of undoped BaTiO3, but the density of states decreases with the increase of doping content. In terms of optical properties, BaTiO3 doping with Ca results in a significant shift in the dielectric peak. After BaTiO3 is doped with Ca, its static dielectric constant becomes smaller. The light absorption of different wavelengths is different after BaTiO3 is doped with different Ca contents. When Ca is 0.125, the light absorption capacity decreases greatly. The research results of Ba1-xCaxTiO3 (x=0, 0.125, 0.25, 0.5) crystals in this paper show a broad application prospects in the field of optoelectronics and provide a theoretical basis for the growth and properties of this series of crystals as well. [ABSTRACT FROM AUTHOR]

Finding a satisfactory third component and obtaining high-performance MgB2 superconductor through simple chemical doping is of great significance to promote the practical process of MgB2. In this paper, three-dimensional carbon（3DC） and three-dimensional carbon supported nickel（3DC/Ni） powders were synthesized by salt template freeze-drying method, and MgB2 blocks containing these two additives were prepared by in-situ doping and solid-state sintering. The phase composition and micro morphology of 3 DC doped MgB2 and 3DC/Ni doped MgB2 were characterized by X-ray diffraction and scanning electron microscope. At the same time, the effects of the two additives on the superconductivity of MgB2 were investigated combined with magnetic measurement system. The results show that 3DC can form effective carbon doping and improve the current carrying performance of MgB2 in high field. After doping 3DC/Ni, under the synergistic effect of Mg-Ni low temperature liquid phase assisted sintering and 3DC providing nucleation sites, the grain connectivity of MgB2 and the flux pinning ability of MgB2 are improved. In this paper, the Ni particles synthesized by freeze-drying method solve the problem of easy agglomeration of small-size doping in nano scale, but the critical current density（Jc） of 3DC/Ni doped MgB2 is not significantly improved because Ni is a magnetic particle. Looking for a more effective metal nanoparticles is the direction of attempt in the future. [ABSTRACT FROM AUTHOR]

Armor-like superhydrophobic metal surface (ASMS) is prepared by sandblasting the aluminum plate surface to build the armored metal surface, and spraying the mixture of superhydrophobic silica and polyurethane to give the armored surface superhydrophobic performance. The microstructure and wettability of the ASMS were characterized by SEM and dynamic contact angle instrument, respectively. At the same time, the mechanical stability and chemical stability of ASMS were evaluated, and its self-cleaning performance was demonstrated. The results show that the ASMS exhibits a static water contact angle of 164° and a rolling angle of 2°. Subsequently, after mechanical stability tests such as average 3.67 N reciprocating friction and wear cycles for 80 times, tape tearing and wearing cycles for 100 times, and water impact for 50 times, the ASMS was able to maintain superhydrophobic performance, and its contact angle is greater than 150°. At the same time, after chemical stability tests such as immersion in strong acid (pH=2) and strong alkali (pH=12) for 72 h, UV irradiation (1.2 W/m~2) for 72 h, and thermal insulation at 200 ℃ for 2 h, ASMS can also maintain superhydrophobic performance, and its contact angle is greater than 160°. The surface preparation in this paper is simple, cheap and easy to batch prepare, which has a wide range of potential applications in the field of large-scale production of superhydrophobic metal materials. [ABSTRACT FROM AUTHOR]

The rapid hemostasis and healing of wounds is of great significance for the treatment of accidental bleeding. As a kind of extremely hydrophilic multi-dimensional network structure gel, hydrogel has great application advantages in hemostatic materials due to its excellent rheology, adhesion and injectability, especially in irregular wounds and deeper wounds. It has an irreplaceable hemostatic effect of other shape materials. Hydrogels such as natural polysaccharide polymers, proteins and synthetic macromolecular polymers have attracted extensive attention due to their high water absorption, biocompatibility, adhesion of blood cell, or activation of coagulation factors in the field of hemostatic materials, and have made great progress in research. In this paper, the preparation of various hydrogel hemostatic materials and the latest application research achievements in recent years are comprehensively reviewed, and the development prospects of hydrogel hemostatic materials are prospected. [ABSTRACT FROM AUTHOR]

Cellulose has the characteristics of renewable, degradable, environmental, pollution-free, etc. Using celluloses as raw materials, the prepared cellulose-based membrane material shows excellent properties of separation, adsorption, conduction, magnetic and stimulus-response, and is widely used in separation, conduction, packaging, adsorption, and other research fields. In this paper, the application of cellulosic materials in the fields of separation film, conductive film, packaging film, and adsorption film was reviewed, and its future development trend was prospected. [ABSTRACT FROM AUTHOR]

Electronic devices will generate electromagnetic waves when they work, and electromagnetic waves will cause electromagnetic pollution while their intensity exceeds a certain range, which can be harmful to people’s health and some precision instruments. In order to eliminate electromagnetic pollution, the research of microwave absorption materials has become more and more important. In recent years, MXene, a member of two-dimensional nanomaterial family, have shown great potential in microwave absorption with their excellent layered structure, rich functional groups and excellent electrical conductivity. Therefore, this paper focuses on the preparation of MXene and the microwave absorption mechanism, and introduces the construction method of 3D MXene composites and its recent progress in the microwave absorption direction. [ABSTRACT FROM AUTHOR]

With the continuous use of fossil fuels, the emission of CO2 increases significantly, which seriously affects nowadays’ ecology. In order to reduce the emission of CO2, it’s urgent to use clean energy to replace fossil fuels. Hydrogen energy has advantages of high heat value and zero CO2 emission, making it a good substitute of fossil fuels. However, its small density and low boiling point make it difficult to storage, which limits its large-scale application. At present, hydrogen energy is stored in high-pressure tanks, which have disadvantages of low hydrogen capacity, high cost of transportation and hydrogen embrittlement. The key point of large-scale commercial application of hydrogen is developing new kind of hydrogen storage materials and technologies. Hollow glass microspheres (HGMs) as a kind of hollow, small size and pressure-resistant material, have advantages of good stability, high hydrogen capacity, low cost and no hydrogen embrittlement, which make them have great potential in hydrogen storage. This paper reviews the development of hydrogen storage in HGMs, introduces the mechanism and influencing factors of hydrogen storage in HGMs and further introduces the research of hydrogen release rate and response time. [ABSTRACT FROM AUTHOR]

The introduction of phosphorus elements inside the epoxy resin by chemical modification can effectively improve its liquid oxygen compatibility, and this will also change the chemical properties of the epoxy resin, but the change of chemical properties remains to be studied. Since it is difficult to characterize some chemical properties in experimental studies, this paper made an in-depth study of the chemical properties of 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phospha-phenanthrene-10-oxide (ODOPB) modified epoxy resin molecules based on the density functional theory (DFT). In order to analyze the effect of chemical properties on grafting ODOPB functional groups into the epoxy resin molecules, the relevant properties of unmodified epoxy resin molecules were also studied and compared. The results showed that the bond dissociation energy and Laplace bond order on the main chain of the epoxy resin molecule increased after ODOPB modification, and the maximum values of the electrostatic potential and average local ionization energy decreased, indicating that grafting ODOPB can improve the thermal stability and liquid oxygen compatibility of the epoxy resin. This study provides the theoretical basis for the study of the ODOPB modified epoxy resin liquid oxygen compatibility mechanism on the molecular level. [ABSTRACT FROM AUTHOR]

In this paper, iron and tungsten co-doped lithium nickelate cathode materials (LiNi0.97 Fe0.02 W0.01) were synthesized by the sol-gel method, and the effect of double cation doping on the electrochemical perform-ance of lithium nickelate cathode materials was studied. The results show that the co-doping of iron and tungsten can significantly reduce the Li/Ni cation mixing, inhibiting the phase transition from H2 to H3, improving cycle stability and reducing the voltage platform decay. At a current density of 200 mA/g, the capacity retention of the LiNi0.97Fe0.02 W0.01O2 material after 100 cycles is 88.1%, while that of the LiNiO, material is only 62.9%. In addition, the LiNi0.97Fe0.02 W0.01O2 material also has more excellent rate performance (the discharge specific capacity is 126.3 mAh/g at a current density of 4000 mA/g). Therefore, the double cation doping is beneficial to improve the electrochemical performance of the cobalt-free high nickel layered oxide cathode material. [ABSTRACT FROM AUTHOR]

To tackle the low conductivity, unstable contact resistance, poor impact strength of conductive adhesive, this paper studies dendritic silver powders as conductive filler on the properties of conductive adhesive. The results show that compared with flake silver powder preparation of conductive adhesive, doping dendritic conductive silver glue show better electrical conductivity, whose volume resistivity decreased 0.8 X 10-3 Ω ⋅ cm. On this basis, the effects of surface treatments such as oleic acid and KI on the electrical conductivity and mechanical properties of the conductive adhesive were explored, and the mechanism of improving the conductive property of the conductive adhesive was analyzed. The results showed that the types of surface treatment agents had a selective effect on the properties of conductive adhesives. The conductive adhesives treated with KI had better conductive properties, and the conductive adhesives with dendritic silver powder as filler showed the lowest resistance (0.9 Ω). The conductive adhesive treated with oleic acid showed better mechanical properties, and the conductive adhesive with flake silver powder as filler had better shear force (570 N), which provided technical support for the research and development of conductive adhesive products. [ABSTRACT FROM AUTHOR]

CO2 is inert and difficult to be fixed, recycled and utilized. One of the effective ways to solve this problem is to prepare cyclic carbonate by cycloaddition reaction between CO2 and epoxides. M(Salen) catalyst is widely used in the cycloaddition reaction because of its simple synthesis and high catalytic activity. However, homogeneous M(Salen) catalyst is difficult to separate, recover and reuse from the product. Therefore, heterogeneous M(Salen) catalyst is an important research direction in this field. In this paper, SiO2 nanoparticles prepared by sol-gel method was used as an inorganic carrier to immobilize Co(III)-Salen complex. The supported catalyst (SiO2@Co(III)-Salen) was characterized by FT-TR, XRD, TGA and SEM, and effects of temperature, pressure, reaction time and catalyst dosage on the cycloaddition reaction of CO2 and propylene oxide were investigated. The optimal reaction conditions were obtained as follows; reaction temperature of 70°C, reaction pressure of 1.5 MPa, reaction time 6 h, and the molar ratio of catalyst to propylene oxide was 1: 500. The yield of cyclic carbonate can reach to 93%. In addition, recycling experiments indicated that the catalytic efficiency reduces significantly after one cycle, which may be caused by the aggregations of SiO2@Co(III)-Salen nanocomposites during the centrifugation process. [ABSTRACT FROM AUTHOR]

Excessive or radioactive I- and IO3- in industrial wastewater may cause thyroid lesions and even carci-nogenesis. It does harm to the ecological environment. Therefore, it is imperative to remove I- and IO3- from wastewater. Adsorption, membrane separation and chemical precipitation are the conventional methods. In recent years, in order to improve the removal efficiency and reduce the secondary pollution caused by the regeneration process of adsorbent, electrochemical and photochemical assisted adsorption have attracted attention of most researchers. In this paper, the basic principles of the above methods are introduced, and the progress of materials for treating iodine-containing wastewater such as ion-exchange resins, layered doublehydroxides,metal organic frame compounds, natural mineral materials, biomass materials and membrane materials are emphasized. Finally, the future research directions are prospected. [ABSTRACT FROM AUTHOR]

M-type barium ferrite (BaFe12O19, BaM) is an excellent hexagonal permanent magnet material with high saturation magnetization, magnetic anisotropy and remanence ratio. It not only plays an important role in promoting the development and manufacture of self-based circulators, but also makes the miniaturization process of microwave antennas and the development of new band radar easier to achieve in the future. In addition, M-type barium ferrite is also a typical double-dielectric magnetic material with good electromagnetic loss and resonance absorption characteristics. It can be used to fabricate absorbing materials with excellent performance, which can be used for harmful electromagnetic wave shielding in life and stealth technology of military aircraft. Therefore, the development and utilization of M-type barium ferrite materials have far-reaching influence on the future people's livelihood and military technology. In this paper, the common preparation methods of M-type barium ferrite in recent years are discussed and reviewed, especially the preparation of M-type barium ferrite single crystal materials. In addition, the crystal structure of M-type barium ferrite and its application as magnetic element in microwave devices are also introduced. [ABSTRACT FROM AUTHOR]

Mechanochromic polymers (MCPs), which can change color or fluorescence in response to mechanical stimuli, show applications in stress sensing and damage visualization. However, MCPs usually display only one color or fluorescence change under an external mechanical stimulus, which limits their use in multimodal analysis of stress and destruction sensing. Therefore, MCPs that exhibit multiple color changes at different intensities or under various types of external mechanical forces have become a research focus. In this paper, the research status of multicolor mechanochromic polymers, including the design strategy and mechanism, is introduced and discussed. [ABSTRACT FROM AUTHOR]

The traditional liquid electrolyte produce dendrites at the negative pole cycle, which cause short circuit of the battery. In addition, there areflammab, explos leak. Solid electrolyte can well solve the above safety problems, and have good stability, that replacement of liquid electrolyte, solid state electrolyte needs to satisfy the requirements, such as high ionic conductivity, wide electrochemical window, excellent chemical compatibility, simple preparation process, low cost and so on. Therefore, it is necessary to further develop high performance solid electrolyte and electrode/electrolyte interface modification materials to optimize and improve the electrochemical performance of solid state batteries. Metal organic frameworks and covalent organic frameworks compounds are newly developed porous materials with periodic structure, which have been widely used in the battery field. This paper reviews the applications and research progress of metal organic frameworks and covalent organic frameworks compounds in solid state lithium ion batteries. At last, how to improve the electrochemical performance of metal organic frameworks and covalent organic frameworks solid electrolytes give. [ABSTRACT FROM AUTHOR]

Soft magnetic composite materials have important applications in many fields. With the development of technology, the performance requirements of soft magnetic composite materials are constantly improving. In order to meet the application requirements of high frequency and high power working conditions, it is necessary to develop soft magnetic composites with low loss and high permeability. SiO2, as an insulating coating medium, has high resistivity and thermal stability, and can be coated on magnetic particles by a variety of methods, so it has been widely used in the field of developing new soft magnetic composites. This paper summarizes the application of sol-gel method, chemical liquid deposition method, reverse microemulsion method, chemical vapor deposition method, double-layer coating method and modified resin coating method in SiO2 insulation coating of iron-based soft magnetic composites. The characteristics of various insulating coating method are summarized and classified according to their characteristics. Some problems faced by SiO2 insulating coating at present are pointed out, and the development prospect of insulating coating methods is prospected. [ABSTRACT FROM AUTHOR]

In this paper, a highly active MgO expansive agent（MEA） with an active reaction time of 41 s was incorporated into ultra-high performance concrete（UHPC） and its effects on the workability, mechanical properties and volumetric stability of UHPC were investigated. Characterization of porosity and pore structure by mercury intrusion method, and the microscopic morphology of the hardened mortars were analyzed by SEM and EDS. The results showed that UHPC will reduce its fluidity and mechanical properties by incorporating MEA, but can significantly compensate for the early autogenous shrinkage of UHPC. The maximum doping of MEA should not exceed 12% of the total amount of cementitious materials. MEA decreases the porosity of UHPC, and refines it, especially for ＜ 50 nm pore size, which is an important reason for the ability of MEA to compensate for the autogenous shrinkage of UHPC. The microscopic test results showed that the main reason for the swelling is that the MEA hydrates in situ to form dense Mg (OH)2, the inhibited crystallization will generate crystallization pressure, which leads to volume expansion. From the EDS results, it can be seen that the boundary between MEA without cementing ability and its hydration products and cement slurry gradually blurs with curing age, and UHPC will tend to be denser. [ABSTRACT FROM AUTHOR]

To fabricate a new type of micro-nanorobot of helical carbon nanowires (HCNs), the truncation, filtration, and magnetic modification were studied for realizing the motion actuated by magnetic field. The treating method of nitric acid oxidation, ultrasonic vibration, and filter paper filtration was proposed to disperse and shorten into 2-8 μm in length. Magnetic modification methods on the surface of HCNs including magnetron sputtering, electroless plating, and hydrothermal growth of Fe3O4 nanoparticles were experimented and compared. The modification effect was evaluated by scanning electron microscopy and element analysis of energy dispersive X-ray spectroscopy. As a result, the HCNs with good magnetic characteristics were obtained. The magnetic-field driving experiments in a micro-channel showed that HCNs modified by magnetron sputtering realized the fast motion speed (3.35 μm/s) and the controllable trajectory motion accuracy ＜5 μm. [ABSTRACT FROM AUTHOR]

In this paper, boron nitride nanosheets (BNNS) were prepared by liquid phase mechanical stripping method and the double modified boron nitride nanosheets (KDBNNS) were prepared by silane coupling agent covalent modification and dopamine non-covalent modification. The reaction induced phase separation was used to distribute KDBNNS at the interface of epoxy resin (EP) and polyether sulfone (PES) to form a thermal conductive pathway. KDBNNS/PES/EP composites were prepared and characterized by Fourier transform infrared spectroscopy analysis, differential scanning calorimetry analysis (DSC), thermal weight loss analysis (TGA), and confocal scanning microscopy. It is observed that BNNS constructs a three-dimensional thermal conductive path in the ternary composite. Studies have shown that when the mass ratio of BNNS is only 3%, the thermal conductivity of the composite reaches 0.394 W/ (m·K), which is 103% higher than pure epoxy 0.194 W/ (m·K) [ABSTRACT FROM AUTHOR]

Aerogel materials have broad application prospects in the market of building thermal insulation materials because of their high porosity, strong compression resistance and low thermal conductivity. In this paper, Al2O3-SiO2 aerogel composite thermal insulation materials with different SiO2 content were prepared by sol-gel method using tetraethyl orthosilicate and sec butanol aluminum as raw materials. The effects of SiO2 doping amount on the crystal structure, micro morphology, mechanical properties and thermal conductivity of composite aerogels were studied. The results showed that Al2O3-SiO2 aerogel was mainly composed of polycrystalline boehmite. SiO2 doping inhibited the formation of γ-Al2O3 phase and hindered the occurrence of hydroxyl condensation reaction. H in AlO—H group was replaced by Si, forming a more stable Al—O—Si bond. Al2O3-SiO2 aerogel showed an open porous structure, and the doping of SiO2 improved the pore orientation of the aerogel, reducing the pore size and distributing evenly. With the increase of SiO2 doping, the compressive strength and specific surface area of Al2O3-SiO2 aerogel first increased and then slightly decreased, and the thermal conductivity first decreased and then increased. When the doping amount of SiO2 was 9 mol %, the maximum compressive strength of the aerogel was 40.92 MPa, which was 58.97% higher than that of the undoped aerogel. The maximum specific surface area was 257.33 m²/g, the lowest thermal conductivity was 0.022 W/（m·K）, and the thermal insulation performance was the best. In summary, the optimal doping amount of SiO2 was 9 mol%. [ABSTRACT FROM AUTHOR]

In recent years, with the rapid development of human society, the global fossil fuel resources have declined significantly, and the existing energy reserves are gradually unable to meet the needs of social development. Therefore, it has become a research hotspot to convert the energy that cannot be used in nature into renewable energy. As an important part of piezoelectric materials, piezoelectric polymer has high strength, high flexibility and high sensitivity to voltage. It can convert mechanical energy, thermal energy, sound energy and vibration energy in nature into electric energy. It has great potential in nanogenerators, sensors, biomedicine and other fields. However, most piezoelectric polymers have the problem of low Curie temperature, so developing new high temperature resistant polymers is an important development direction at present. In this paper, the research progress of several widely used piezoelectric polymers (polyvinylidene fluoride, nylon 11 and polyacrylonitrile） is firstly introduced, and then the development of high temperature resistance of these materials is discussed. [ABSTRACT FROM AUTHOR]

In this paper, bare and nano-CeO2 modified multi-scale WC-10Co4Cr powders and coatings were prepared. The powder fabrication process mainly involved ball milling of a mixture of 0.06-0.18 μm nano WC, 0.4-0.6 μm submicron WC, 2.2-2.6 μm micron WC, Co, Cr3C2, and nano CeO2, followed by spray drying and sintering. JP8000 HVOF spray system was used to deposit the WC-10Co4Cr coatings on 316 stainless steel substrates. The impact of nano-CeO2 on the microstructure of multiscale WC-10Co4Cr coating was analyzed by optical microscope, scanning electron microscope and X-ray diffractometer. The cavitation erosion resistance and cavitation behavior of the coatings were studied in fresh water medium. The cavitation mechanism of the coatings was further explored by comparing the microhardness, porosity and cracking toughness of the coatings. The results show that both the bare and nano CeO2 modified multiscale WC-10Co4Cr coatings prepared by HVOF are mainly composed of WC phase and amorphous CoCr with no obvious decarburization. The nano CeO2 modified multiscale WC-10Co4Cr coating has lower porosity of 0.25% compared to the bare multiscale WC-10Co4Cr coating（0.32%）. However, the microhardness of the nano CeO2 modified coating is lower(1 134 HV0.3), only 83% of that of the multi-scale WC-10Co4Cr coating. Similarly, the cracking toughness(5.27 MPa·m1/2) of nano CeO2 modified is 4% lower than that of the multiscale WC-10Co4Cr coating. In the multiscale WC-10Co4Cr coating, the nano CeO2 leads to the decline of the cavitation erosion resistance of the coating in fresh water, with the cavitation erosion rate reaching 1.64 times the rate of the multiscale WC-10Co4Cr coating in the stable cavitation stage. It is concluded that the addition of nano CeO2 reduces the porosity of the WC-10Co4Cr coating, while the mechanical properties of the coating decrease, thereby reducing the cavitation resistance of the coating. [ABSTRACT FROM AUTHOR]

Carbon quantum dots (CDs) are widely used in various fields due to their unique physical or chemical properties. Compared with traditional semiconductor quantum dots, the biggest advantages of CDs are low cytotoxicity, high biocompatibility, and at the same time being environmentally friendly. Obtaining carbon dots that meet the application conditions by selecting a specific synthesis or modification method is an urgent need for researchers. This paper reviews various top-down and bottom-up synthesis methods of CDs and describes their various properties after synthesis, in which the top-down method is biased towards producing a larger amount of Cdots, but the size and Cdots form is difficult to control. The bottom-up method can better control the size and shape of carbon dots, but the process is more complicated and time-consuming. The research progress of surface modification of CDs, including surface passivation and surface functionalization, was further discussed. Moreover, the characteristics of Cdots prepared by different synthesis methods or modification methods are quite different, extending their applications in various aspects, including cell imaging, fluorescence sensing, drug delivery, photocatalysis, ion detection, etc. Finally, we summarize and analyze the aspects of carbon dots that can be further explored, in order to provide references for more in-depth research and wider application of carbon dots. [ABSTRACT FROM AUTHOR]

In this paper, CaF2:20Yb2Er/Na@CaF2:Ce nanoparticles were prepared by thermal decomposition method, its NIR-Ⅱ luminescence performance and fluorescence lifetime were explored. The results show that the NIR-Ⅱ luminescence intensity is about 68 times that of CaF2:20Yb2Er when excited by 980 nm light source. And the fluorescence lifetime at 1 525 nm is 2.29 ms. In this sample, Yb3+ acts as sensitizer, Er3+ acts as activator, the local symmetry of the crystal field is destroyed after Na+ co-doping, and the fluorescence quenching in the luminescence center can be minimized with the construction of core-shell structure. After the introduction of Ce3+ into the shell structure, cross-relaxation effect generated from Er3+ and Ce3+ exists at the interface. Thus it can be seen that the combination of ion co-doping and core-shell structure construction is more conducive to the improvement of the NIR-Ⅱ luminescence performance. The CaF2:20Yb2Er/Na@CaF2:Ce nanoparticles have potential applications in the field of bioimaging. [ABSTRACT FROM AUTHOR]

The use of oily organic solvents in the production of water-resistant sandpaper causes the environmental problems. Meanwhile, phenolic resin adhesive will result in the shortcomings such as the brittleness of sandpaper. In order to solve these problems, the lignin modified phenolic resin was synthesized by adding toughening agents of polyethylene glycol (PEG) or polyvinyl alcohol(PVA). The lignin modified phenolic resin adhesive was prepared after ethanol dilution for water-resistant sandpaper. The water absorption, the mechanical properties and the grinding properties of modified resin roll-coated paper base were investigated. The results showed that the modified phenolic resin adhesive with solvent lignin and 1.0 wt% PEG 600 is good for low water absorption. The water absorption of the paper base was 0.035 g/(m²·s) with 130 min of the reaction time, 160 ℃ of the curing temperature and 10 min of the curing time. It was 20.45% lower than that of the paper base when the reaction time was 60 min. The wet tensile strength of paper base was 10.28 kN/m, and the z-direction tensile strength was 1 002.7 kPa when the reaction time was 150 min. They were 22.23% and 31.17% higher than those of 60 min, respectively. Paper base showed the lowest water absorption, the highest wet tensile strength and the moderate z-direction tensile strength, when 1.0 wt% PEG 600 was added and the solid content of modified resin was 25%. Water absorption, wet tensile strength and z-direction tensile strength were 0.036 g/（m²·s）, 10.56 kN/m and 886.4 kPa, respectively. The phenolic resins were modified by adding 0.8 wt% and 1.0 wt% PEG 600 as toughening agents. The solid content of the modified resin after dilution was kept between 25% and 30%. The sandpaper was made from the paper base treated with the modified resin, and the standard aluminum bar was ground with the sandpaper. The sandpaper showed no tearing or peeling after grinding for 30 min which meets the qualification requirements. [ABSTRACT FROM AUTHOR]

The two-dimensional material MXene with layered structure has attracted the attention of most researchers due to its outstanding conductivity, good hydrophilicity and rich surface chemical structure. This paper focuses on the advanced preparation methods and processes of transition metal carbonitrides, and reviews the research progress of their electrical aspects (including supercapacitors, battery materials and electrocatalysis). In MXene supercapacitors, compared with conventional aqueous electrolytes, organic electrolytes or ionic electrolytes can often provide higher output voltage, resulting in higher energy density. At the same time, the chemical properties of solvents also have a great influence on the molecular/ionic arrangement n MXene. As far as mxene based battery materials are concerned, the layered structure prepared by changing the assembly method of mxene sheet and electrode manufacturing method can prevent aggregation and reaccumulation, and the introduction of cation vacancy can also effectively improve the performance of MXene based battery materials. In add-on, several strategies. to improve the performance of MXene based material for electrocatalytic water de- composition are discussed. The purpose of this paper is to review the preparation, structure, application and op- ionization of MXene in electricity, and to discuss the future research direction and possible challenges. [ABSTRACT FROM AUTHOR]

In recent years, the development of sound-absorbing materials has advanced rapidly, and been widely used in traffic buildings and other areas. Tn this paper, the characteristics and research progress of sound absorption materials are reviewed, and the basic principle of sound absorption is discussed. Tn addition, starting from the preparation of sound absorbing materials, this paper mainly introduces the research progress of the sound absorbing characteristics and material structure of porous, resonant and composite sound absorbing materials. Tt is a key research direction that how to use the improvement of the internal structure of the material to achieve efficient noise reduction in the field of sound absorbing materials. Finally, the problem about how to correlate the damping loss factor of acoustic materials with the acoustic coefficient is put forward. And the sound absorption effect is studied based on the correlation. So the acoustic performance can be controlled by the design of material damping factor. [ABSTRACT FROM AUTHOR]

Aiming at the problems of insufficient flexural strength and low durability of cement concrete, this paper prepared concrete with different content of epoxy resin（0%, 3 wt%, 6 wt%, 9 wt%） by using epoxy resin as doping phase, and analyzed the influence of epoxy resin on the mechanical properties, micro appearance and durability of cement concrete. The results show that the doping of epoxy resin accelerates the hydration reaction, reduces the number of cracks and pores, and improves the density of concrete. The compressive strength and flexural strength both increased first and then decreased with the increase of resin doping. The compressive strength and flexural strength of the concrete with 6 wt% epoxy resin doping reached the maximum values of 43.8 and 7.9 Mpa respectively when cured for 28 d, which increased by 18.70% and 29.51% respectively compared with the concrete without resin doping. The chloride ion diffusion coefficient of concrete decreases first and then increases with the increase of resin doping amount. The chloride ion diffusion coefficient of concrete with 6 wt% epoxy resin doping content for 28 d is the lowest of 7.7×10-8 cm/s, and the chloride ion corrosion resistance is the best. When the number of freeze-thaw cycles reaches 80, the concrete with 6 wt% epoxy resin doping has the lowest mass loss rate of-0.13%, the highest relative dynamic elastic modulus of 94.86%, the lowest wear amount of 0.66 kg/m², and the wear amount reduction rate of 46.77%. It has excellent durability. [ABSTRACT FROM AUTHOR]

Mannitol and inositol, as sugar alcohol phase change materials with high latent heat, have wide application prospects in medium temperature thermal energy storage. The phase change temperature of binary sugar alcohol can be adjusted by changing the proportion of the sugar alcohol components, thus the temperature range of application is wider than that of one-component sugar alcohol. There are some problems such as leakage, oxidation and supercooling during the thermal cycles of sugar alcohols. Micro/nanoencapsulation of sugar alcohols and addition of nucleating agent are effective measures to solve the problems. In this paper, silicon carbide doped mannitol and inositol binary sugar alcohol nanocapsules were prepared. Phase change characteristics and thermal stability of the nanocapsules were studied by differential scanning calorimeter, scanning electron microscope, thermogravimetric analyzer and thermal cycling test, and the influence of silicon carbide was discussed. The results show that the nanocapsules have high phase change enthalpy, high encapsulation rate and high energy storage efficiency. The thermal decomposition temperature is higher than that of the binary sugar alcohol. The supercooling degree of the nanocapsules decreases by 32.2 ℃ compared with the binary sugar alcohol after thermal cycling. [ABSTRACT FROM AUTHOR]

In this paper, unsaturated polyester resin was selected as the matrix material, glass fiber as the reinforcing phase, and polyester glass fiber composites with different glass fiber doping（0, 5 wt%, 10 wt%, 15 wt% and 20 wt%） were prepared by molding process. The effects of glass fiber on the micro morphology, thermal stability, tensile properties and bending properties of the composites were analyzed. The results show that the glass fiber and unsaturated polyester in the polyester glass fiber composites are mainly physical effects, and the glass fiber can be closely combined with the polyester substrate after doping, and the distribution is directional. The decomposition temperature of polyester glass fiber composites first increases and then decreases with the increase of glass fiber doping, and the heat resistance improves. T50% of the composites with 15 wt% glass fiber doping reaches the maximum value of 368.47 ℃. The mechanical properties test shows that with the increase of glass fiber doping, the tensile strength and impact strength of polyester glass fiber composites first increase and then decrease, and the fracture elongation and bending strength continue to decrease. The mechanical properties of 15 wt% glass fiber doped polyester glass fiber composites are the best, with the maximum tensile strength of 26.1 MPa, the fracture elongation of 2.6%, the maximum impact strength of 8.1 MPa and the bending strength of 30.5 MPa. [ABSTRACT FROM AUTHOR]

CoFeB has the large saturation magnetization and low damping constant, which makes it a suitable material to fabricate the memory devices by controlling domain wall moving. In this paper, we investigate the kinetic interactions between spin waves and transverse domain walls in CoFeB nanostrips by means of micromagnetic simulations. The simulation results show that the speed and direction of domain wall movement are not only influenced by the spin wave frequency, but also closely related to the applied magnetic field strength and nanostrip’s width. When the spin wave frequency is low, the domain wall is difficult to be driven. As the spin wave frequency increases, the domain wall starts to move in the direction opposite to the propagation of the spin wave. With the increase of the strength of the applied magnetic field, the velocity of the domain wall moving in the reverse direction increases and then decreases until it becomes forward. When the spin wave frequency is higher than 7 GHz, the domain wall moves in the same direction as the spin wave propagation, and the velocity of the domain wall shows a multi-peak feature with the spin wave frequency, with the maximum velocity obtained to be 384 m/s. When the domain wall moves forward, its velocity gradually increases with the increase of the strength of the applied magnetic field. As the width of the nanostrip increases, both the mass of the domain wall and the inhomogeneity of the effective field increase, causing the maximum velocity of the domain wall to increase and then decrease. The use of CoFeB nanostrips can effectively improve the domain wall velocity, and the strength of the applied magnetic field and the width of the nanostrip have a significant effect on the domain wall velocity, which provides a new way to optimize the device performance. [ABSTRACT FROM AUTHOR]

The development of transition metal electrocatalysts with efficient and durable activity of oxygen evolution reaction（OER） is important for clean hydrogen production. In this paper, amorphous binary metal hydroxides CoFe（OH）x were prepared by the template method. The phase structure and micromorphology of the catalyst were characterized by using X-ray powder diffraction instrument（XRD）, Fourier transform infrared spectrum（FT-IR）, field emission scanning electron microscope（SEM）, and laser Raman confocal microscope Raman spectrometer（Raman）. The catalytic performance of the catalyst in the oxygen precipitation reaction was investigated by the standard three-electrode system in an alkaline solution of 1 mol/L KOH with a saturated N2 atmosphere. Because of the presence of a large number of defects and reactive sites in the amorphous structure as well as intermetallic synergy, the overpotential of CoFe（OH）x/65 was 288 mA at a current density of 10 mA/cm² by electrochemical testing. In addition, it showed good OER stability without significant weakening during 14 h of stable operation. [ABSTRACT FROM AUTHOR]