The SiO₂ in the molybdenum tailings is purified by high-temperature heating and pickling, and the surface is modified with methylhydrogen-containing silicone oil and dimethyl diethoxysilane(DDS).The results show that the impurities such as calcium and magnesium can be effectively removed, and the purified content of silicon oxide can reach 84.3%. When methyl hydrogen-containing silicone oil is used as a modifier, the activation degree of modified slag can reach 77.6%, and the maximum contact angle can reach 116°. Methyl hydrogen-containing silicone oil can be effectively grafted onto the surface oftailing particles. When dimethyl diethoxy silane is used as a modifier, the activation degree can reach 95%, the contact angle can reach 130°, and dimethyl diethoxy silaneis uniformly coated on the surface of tailing particles. The application of modified molybdenum tailings silica in ammonium hydrogen phosphate extinguishing agent shows that it can improve the water repellency of ammonium hydrogen phosphate extinguishing agent.

Carbon foams were prepared via molten salt-assisted combustion synthesis with polyvinyl chloride (PVC) as a carbon source, magnesium powder (Mg) as a reducing agent, ferrocene (Fc) as a catalyst and different kinds of molten salts (i.e., NaCl, KCl, and MgCl₂) as a porogen. The products were characterized by X-ray diffraction, scanning electron microscopy, Raman spectroscopy and specific surface area measurement. The electromagnetic shielding specimens were prepared with carbon foam as an absorbent and paraffin as a binder. The electromagnetic shielding effectiveness of the samples in the frequency range of 8.2-12.4 GHz was tested by a rectangular waveguide method. The results show that the optimum foaming effect is achieved when NaCl is used as a porogen, and the well-developed hollow spherical carbon foams with the pore sizes of 100-500 nm are obtained after washing and leaching. Molten salts have a positive effect on the graphitization degree and micro-morphology of carbon foams, in which NaCl shows an optimum accelerating-effect. The combustion synthesized products have a good electromagnetic shielding performance. The carbon foams with NaCl as a molten salt have an optimum electromagnetic shielding efficiency (i.e., up to 39.5 dB).

A hypothesis on 'centroplasm of cement-based composite' was proposed by Wu Zhongwei 60 years ago. Although his hypothesis is rather advanced, it has not been clarified so far. The innovation of the hypothesis is to break the conventional boundaries between cement chemistry and concrete chemistry. In his hypothesis, concrete should be regarded as a holistic system with hierarchy and openness. Effect of interface between centroplasm and matrix is extended to be negative and positive. Pore is considered as a negative centroplasm although it is "empty", thus being benefit to some properties of products. In addition, his hypothesis also gives the corresponding model and some further research aspects.

Composite red luminescent material Sr₂MgSi₂O₇: Eu²⁺, Dy³⁺/light conversion agent is a kind of long-afterglow luminescent material prepared with a light conversion agent and Sr₂MgSi₂O₇: Eu²⁺, Dy³⁺ at a certain mass ratio. This material has excellent characteristics (i.e. high brightness and good stability) of Sr₂MgSi₂O₇: Eu²⁺, Dy³⁺. Also, it can emit a red light. In this paper, silane coupling agent (i.e. KH560), aluminate-coupling agent (i.e. DL-411-A), zircoaluminate coupling agent (i.e. LD-139-3) and their composite coupling agents (i.e. A: composite of silane coupling agent and aluminate coupling agent; B: composite of silane coupling agent, aluminate coupling agent and aluminum zirconium coupling agent) were used to prepare the composite red luminescent materials. The effects of coupling agent on the luminescence properties were investigated. The surface morphology, phase structure and luminescence properties of the composite luminescent materials were characterized by scanning electron microscope, X-ray diffractometer, fluorescence spectrometer and afterglow luminance meter. The results show that three coupling agent all can improve the luminescence performance of composite luminescent materials, and the composite coupling agent has a better effect. The surface of Sr₂MgSi₂O₇: Eu²⁺, Dy³⁺ becomes coarse and adheres to the massive light conversion agent particles when a composite coupling agent B is used. In this case, the emission peak intensity of the sample is increased by 1.89 times at 605 nm, but decreased by 72% at 470 nm, the initial afterglow brightness is increased by 1.86 times, and the color purity is enhanced by 1.87 times.

Double-layer TiO₂-SiO₂/SiO₂ composite anti-reflective thin films with W transmittance line type were prepared by a sol-gel method, and the refractive index of TiO₂ and composite TiO₂-SiO₂ thin films was regulated. The preparation condition on the TiO₂ thin film refractive index was investigated. The phase, film components, refractive index and transmittance of the films were characterized by field emission scanning electron microscopy, energy disperse spectroscopy, ellipsometry and ultraviolet-visible-infrared spectrophotometry, respectively. The transmittance line type of double-layer composite films was simulated by a software named TFcal. The results show that the pH value of sol system is more crucial to the refractive index of TiO₂ thin films, and the refractive index decreases when the pH value increases, compared to the ratio of H₂O/Ti. Meanwhile, the pH value derived hydrolysis rate has an effect on the refractive index of the final film. The composite TiO₂-SiO₂ films used as the bottom layer of the films system are obtained when the mixture mole ratio of Ti/Si is 1.2∶1.0 and the refractive index is 1.68. The double-layer TiO₂-SiO₂/SiO₂ composite thin films obtained have an antireflection effect in the wide optical wavelength range of 380-1 100 nm, and the maximum transmittance can reach to 97%.

The porous α-Fe₂O₃ was used as solid support, and silver nanoparticles were integrating into the pore of α-Fe₂O₃ through hydrothermal synthesis. Four different amounts of AgNO₃ were added into the growth media for optimizing the surface-enhanced Raman scattering (SERS) performance of Fe₂O₃-Ag. The structure and component of the Fe₂O₃-Ag nanocomposites were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and N₂ adsorption. The experimental results show that the BET surface area and enhancement factor of the Fe₂O₃-Ag nanocomposite are 26.57 m²/g and 10²-10³ respectively, when the dosage of AgNO₃ is 6.5% (in mass), exhibiting the best SERS enhancement. The Fe₂O₃-Ag nanocomposite provides not only the SERS enhancement but also a good adsorption performance, which could be further used for absorption and detection of various samples.

In order to improve the electron transport rate of TiO₂ photoanode, multi-walled carbon nanotubes (MWCNTs) were loaded in TiO₂. TiO₂/MWCNTs composite sols were formed by a sol-gel hydrothermal method, and the uniform TiO₂/MWCNTs composite films were formed by an electro-hydrodynamic method. The films were optimized with TiCl₄. The samples were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffractometer and ultraviolet-visible absorption spectroscopy. The photoelectric properties of dye-sensitized solar cells (DSSCs) based on TiO₂/MWCNTs composite photoanodes and SnO₂/MWCNTs counter electrode were analyzed by electrochemical impedance spectroscopy and current density-voltage curve measurement. The results show that the addition of MWCNTs considerably accelerates the transport of electrons in the films and decreases the recombination of electrons with oxidized dye and I₃^-; The DSSC with a CNT-0.12 (0.12%, in mass) composite photoanode shows the optimal performance (i.e., V_oc=0.70 V, J_sc=13.0 mA/cm², η_FF=0.64, η=5.80%), and the power conversion efficiency is 30.6% greater than that of DSSC with a pure TiO₂ photoanode (i.e., η=4.44%).

F-doped SnO₂ (FTO) thin films with the thickness of 20-400 nm were prepared via reactive magnetron sputtering at 150-300 ℃ using Sn+SnF₂ as a target, and the prepared FTO films were further treated by ultraviolet (UV) irradiation. The effects of film thickness and UV irradiation time on the structural, optical and electrical properties of FTO films were investigated. The results show that the crystallinity of FTO films improves and the preferred orientation remains (211) plane with the increase of film thickness or substrate temperature. Meanwhile, the compressive stress existed in the films increases and the conductive properties of films degrade. The transmittance of the films firstly decreases and then increases, and their energy gap (E_g) firstly increases and then becomes stable when the film thickness increases. Increasing substrate temperature can increase the transmittance and E_g of the films. UV irradiation can increase the carrier concentration of the films, thus enhancing the conductive properties of the film, but it has little effect on the transmittance of the film. In addition, the influence of film thickness on the structural, optical and electrical properties of FTO films was discussed, and the mechanism of improving the optical and electrical properties of FTO film by UV irradiation was analyzed. This study could provide a reference for the preparation of FTO thin films by magnetron sputtering technology and the improvement of their properties.

The stability and electronic structures of the arsenene/WS₂ van der Waals heterostructure at different electrical field intensities and strains were investigated via the first-principles calculation based on the density functional theory. The calculation results show that the arsenene/WS₂ heterostructure possesses a type-II band alignment and an indirect band gap. Moreover, the external electrical field modulates the band gap and brings the band alignment transition from type-Ⅱ to type-Ⅰ in the heterostructure. In addition, the band gap can be effectively tuned by the strain, while the type-Ⅱ band alignment is robust under the strain.

The stable GaInSe₂ monolayer as a Janus structure with an indirect band-gap was investigated via first-principles electronic structure calculations. The intrinsic correlation between GaInSe₂ monolayer and its binary analogues (GaSe and InSe monolayers) was investigated in terms of atomic structure and electronic property. The calculation results of atomic structure and phonon frequency dispersion indicate that GaInSe₂ monolayer has a dynamically stable Janus structure with the similar hexagonal geometry as GaSe and InSe monolayers. The electronic band structures show that GaInSe₂ monolayer and its binary analogues are all indirect band-gap semiconductors. It is noted from the strained Janus model that work functions and coherent strains of GaSe and InSe constituents essentially determine the electronic structure of GaInSe₂ monolayer. GaInSe₂ monolayer can be converted into direct band-gap semiconductor when the strain in atomic plane is decreased less than a critical value. Therefore, GaInSe₂ monolayer can be applied to 2-dimensional or surface photoelectric materials under the mechanical conditions below the critical strain. Further, the band-edge character and band-gap width can be effectively controlled by modifying the strains in atomic plane of GaInSe₂ monolayer, which is of great significance for the potential application in field effect nanotransistors.