Silico-manganese slag is a main solid waste produced from production of silicon-manganese alloy, which affects the environment. It is thus necessary to explore the corresponding disposal methods since the exsiting processing technology restricts the absorbing capacity. A microcrystalline cast stone was fabricated by the Petrurgic firing method with silico-manganese slag as a raw material. The bulk density, microhardness, flexural and compressive strength of the samples were determined. The influences of crystallization temperature and time on the phase structure and properties of the finished product were invesigated. The results show that a hot molten slag is cooled to 950 ℃ for 60 min and then annealed at 760 ℃, obtaing a microcrystalline cast stone with the superior properties. The microcrystalline cast stone has a compact structure, and the precipitated crystal phases are mainly clinopyroxene, diopside and aluminum diopside, as well as anorthite and wollastonite. The bulk density of the cast stone can reach 3.11×10³ kg·m^-3, the microhardness is 8.77×10³ MPa, and the flexural strength and the compressive strength are 86 MPa and 222.9 MPa, respectively.

To solve the problems of thermal shock resistance and radiation efficiency attenuation due to the high-temperature oxidation of silicon carbide porous ceramics used in high-temperature combustion of porous media, a silicon carbide billet was prepared by an organic foam impregnation method. Also, porous silicon carbide ceramics containing cordierite infrared radiation coating were fabricated on the surface of silicon carbide skeleton via in-situ reaction sintering. The results show that the vacuum impregnation slurry can coat the skeleton surface and completely fill up the triangular holes of the silicon carbide skeleton. The three-layered porous silicon carbide ceramics with a cordierite coating, the central layer of the silicon carbide skeleton and the cordierite filling layer were prepared by sintering at 1 350 ℃. The mechanical properties, thermal shock resistance and high-temperature wet oxidation resistance of porous silicon carbide ceramics are improved due to the formation of the three-layered structure. The compressive strength of porous silicon carbide ceramics is 1.18 MPa after heat-treatment at 1 350 ℃, and the residual strength retention rate is 67%. According to the results of porous media combustion experiments, the three-layered structure of silicon carbide porous ceramic with a surface reinforcement by cordierite infrared radiation coating can reinforce silicon carbide porous media burner radiation heat transfer process and increase the combustion efficiency, thus increasing the burner surface temperature by 140 ℃ and reducing the emissions of CO and NO_x pollutants in the burner.

Sewage sludge and household garbage are used as an alternative fuel in recent production of cement. However, the alternative fuel causes serious alkali attack and spalling of bauxite-SiC refractories for cement kiln lining, thus having an impact on the operation of the cement kiln. In this paper, the alkali vapor exposure was used to evaluate alkali attack on some raw materials like bauxite, mullite (M60) and molochite, which were used to prepare mullite-SiC composite refractory as a lining of cement kiln. The results show that the alkali attack resistance of these raw materials is closely related to their chemical composition, phase composition and microstructures. Bauxite with corundum and mullite as main phases is attacked by alkali to form a kaliophilite phase and induce cracks and loose structure, further enhancing gaseous alkali penetration and serious damage. Mullite (M60) with mullite as a main phase is attacked by alkali to form leucite and transient liquid phase. The resultant liquid phase prevents from the penetration of alkali, and the attack only occurs on the surface layer, so mullite (M60) exhibits a superior alkali attack resistance. Molochite with mullite and glass (the content of 46%) reacts with alkali vapor to form more liquid phase and leucite. As alkali vapor is dissolved in the glass phase of molochilte, the integrity of molochite is destroyed by alkali attack.

Aluminum nitrides are considered as high-performance thermal conductive substrate and packaging materials due to the remarkable properties, including high thermal conductivity, high electrical resistivity, low thermal expansion coefficient, low dielectric loss and excellent mechanical properties. This review represented the preparation techniques, properties and applications of AlN powders and ceramics. The challenges and implications for aerospace application were discussed. In addition, their potential applications for spacecraft electronics were also prospected.

Optoelectronic functional films and devices are widely used for applications in flat display, solid-state lighting, information transmission and storage, new energy and photochemistry. The research highlights in this field rely on developing protocols for further improving their performance. Additive manufacture, that is 3D printing as a simple, high-precision, no mold-required, material-saving, personalized and batch-oriented intelligent fabrication technology, has attracted recent attention. This review reported the major additive manufacture techniques for developing optoelectronic functional films and devices and their research progress via highlighting inkjet printing, electrohydrodynamic printing and direct writing capable of printing optoelectronic functional films with three-dimensional structures and deliberating the challenges in realizing complex shape and in-situ multiscale modulation in microstructure. Aerosol jet printing was emphasized with great potential for simultaneously controlling the nano-and micro-structures during printing optoelectronic functional films via exploiting the microreactor capabilities of aerosols. Carbon-based materials and MXene were taken as examples for demonstrating the functionality and applicability of additive manufacture techniques in printing optoelectronic functional films and devices. Recent studies on the additive manufacturing of advanced optoelectronic functional materials and devices were summarized, i.e., developing new material and ink formulation, printing process control and new additive manufacturing processes. In addition, the future development was also prospected for next-generation additive manufacture protocols endowing the functionality of in-situ multiscale modulation of microstructures during the printing process, thus favoring the development of high-performance optoelectronic functional materials and devices in the future.

Cement hydration is a key process to determine most properties of cementitious materials. Clarifying the mechanisms of cement hydration intersects both academic and practical interests. Recent research work on Portland cement hydration kinetic models was reviewed. The hydration simulation models, such as GEMS thermodynamic calculation, HymoStruc3D and CEMHY3D and other hydration simulation models and their limitations were discussed. The application of quasi-elastic neutron scattering and nuclear magnetic resonance methods in the evolution of water states and the development of pore structure during cement hydration process were summarized. In addition, this review also gave the future developemt and challenges in this field.

Refractory castables are green materials for the development of refractory industry due to their advantages of low energy consumption, simple process and convenient mechanized construction. However, water-containing castables are prone to structural damage and even explosive spalling during the heating process of drying, so as to shorten the service life of components and cause economic and resource losses under the combined action of thermal stress caused by temperature gradient and internal pressure caused by water vapor. From the perspective of the anti-spalling of castables, this review represented the basic mechanism of explosive spalling, the microstructure and spalling resistance of typical bonding systems, anti-spalling means, test methods and numerical simulation, and gave the future related research aspects.

Lithium cobalt oxide is a leading cathode material for 3C electronic products because of its high bulk energy density, excellent rate capacity and good cycle performance. The existing gram capacity of lithium cobalt oxide material in practical application is approximately 65% of the theoretical capacity, and this material has a potential for further development. In this paper, a lithium ion cobalt oxide cathode material was coated with lithium ion conductor material LiAlSiO₄ by a sol-gel method. The effects of LiAlSiO₄ and heat treatment temperature on the structure, morphology and electrochemical properties of the material were investigated. The results show that during the heat treatment, Al³⁺ enters the LiCoO₂ lattice to form a solid solution LiCo_1-xAl_xO₂, and an inert coating layer is formed on the surface of the lithium cobalt oxide particles LiAlSiO₄ coating, effectively improving the cycle and rate performance of the lithium cobalt oxide material at a high voltage. The optimum overall performance of the lithium cobalt oxide material coated with LiAlSiO₄ can be obtained at a heat treatment temperature of 600 ℃. In a voltage range of 2.75-4.55 V, the specific discharge capacity at room temperature at 0.5 C rate is 209.3 mA·h/g, and the discharge specific capacity after 50 cycles is 201.6 mA·h/g (at a capacity retention rate of 96.3%), and the specific capacity is 160.0 mA·h/g at 8 C.

The morphology of nanomaterials can affect their electrochemical performance. It is a challenge to design metal oxide nanostructures with controllable morphology/size and good electrical conductivity for their application in electrochemical supercapacitors and other energy storage devices. NiMn₂O₄ electrode materials with different amounts of polyvinylpyrrolidone (PVP) were prepared by a co-precipitation method. The effect of PVP (0, 0.2, 0.4, 0.8 g) amount on the microstructure and capacitance properties of NiMn₂O₄ was investigated. The results show that the microstructure of NiMn₂O₄ changes from an agglomerated granular to loose flocculent and fine powder with the increase of PVP content. The optimum capacitance performance of NiMn₂O₄ can be obtained at PVP amount of 0.4 g, and the specific capacitance of NiMn₂O₄ is 1 464 F/g at a current density of 1 A/g. At PVP amount of 0.8 g, the excessive amount of PVP is easy to cause residue in NiMn₂O₄ in the cleaning process. During the electrochemical test, the amount of active substances involved in the redox reaction is relatively reduced, leading to the decrease of the capacitance performance of NiMn₂O₄-0.8. The specific capacitance is 1 010 F/g when a current density is 1 A/g.

SnO₂ is widely investigated as one of anode materials for lithium-ion batteries due to its natural abundance, low discharge potential (less than 1.5 V) and high theoretical capacity. However, the low electrical conductivity and large volume expansion (300%) during Li⁺ insertion/extraction results in the poor cyclability and rate capability of SnO₂, thus restricting its practical applications. In this study, SnO₂@C/rGO nanocomposites were prepared by an one-step hydrothermal method with SnCl₂, L-ascorbic acid and GO as reactants. The L-ascorbic acid-derived amorphous carbon served as a spacer to inhibit the stacking of rGO sheets and acted as a coupling agent to strongly anchor SnO₂ nanoparticles on the rGO sheets. The as-obtained SnO₂@C/rGO nanocomposite delivers a specific capacity of 731 mA·h/g after 180 cycles at a current density of 0.1 C (1 C= 783 mA/g) and a high reversible capacity of 410 mA·h/g at a large current rate of 5 C. This study provides a promising route for the preparation of high-performance SnO₂ anode materials.