The effect of Ca or Y (2 % and 3 %, mass fraction, respectively) on hot tearing behavior of Mg-1.5% Zn alloy was investigated using a constrained rod casting (CRC) apparatus equipped with a load cell and data acquisition system. Tear volumes were quantified by wax penetration method. The experimental results show that the addition of Ca or Y could significantly decrease the hot tearing susceptibility (HTS) of the Mg-1.5Zn alloys due to that they could reduce the solidification temperature range (ΔT) for vulnerable regions. The reduction in ΔT may correspondingly imply the decrease of the HTS. In addition, the HTS further reduces with the higher amount of Ca or Y. It is observed that some of the formed cracks are possible to be healed by the subsequent refilling of the remained liquids during the final solidification stage, while the propagation of hot cracks along the dendritic and grain boundaries may be ascribed to the interdendritic separation or liquid film rupture.

Hierarchically porous iron (Ⅲ) trimesate Fe-MIL-100 were synthesized by hydro-thermal route of HF free in a large scale, with ironic nitrate and trimesic acid as raw materials. The structure and morphology of Fe-MIL-100 were characterized by X-ray diffraction (XRD), N₂ physical adsorption, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TG). The effect of temperature, HNO₃ addition, time and post-treatment on the structure of Fe-MIL-100 were investigated. The results show that the prepared Fe-MIL-100 has high crystallinity with BET surface area up to 1744 m²/g. The prepared materials have good thermal stability, which can withstand temperature up to 520 ^°C before decomposition in nitrogen.

The compression deformation behavior of ultra-high strength dual phase steel (UHS-DP1000) was investigated by strain rates from 0.05 s^-1 to 10 s^-1 at temperatures from 950°C to 1150°C. The influence of deformation temperature and strain rate on the hot flow curves was analyzed. Then a constitutive model for hot deformation of the steel UHS-DP1000 was established based on the dislocation density theory. The relevant softening mechanism of the steel was revealed in terms of the following two aspects that by low strain rates (lower than 0.05 s^-1) at high temperatures the dynamic recrystallization (DRX) softening mechanism was more evident, while by strain rates higher than 0.1 s^-1 the dynamic recovery (DRV) softening mechanism was dominant. The two softening mechanisms worked simultaneously by strain rates in a range between 0.05 s^-1 and 0.1 s^-1. The stress-strain values predicted by the present model for the steel UHS-DP1000 are well agreed with those acquired from experiments, which further confirmed that the established constitutive model could give an accurate estimate for the flow stress of high temperature deformation of the steel UHS-DP1000.

Silver nano-particles were deposited on the surface of aramid fibers by a two-step process i.e. firstly coarsening the surface of aramid fibers with sodium hydroxide and then Ag electroless plating. The Ag-plated aramid fibers were characterized by scanning electron microscope (SEM), atomic force microscope (AFM), X-ray photoelectron spectrometer (XPS) and X-ray diffractometer (XRD). The mechanical properties, thermal stability, and electrical resistance of the Ag-plated aramid fibers were examined by thermogravimetric analyzer (TG) and digital multimeter. The results show that the plated Ag is homogeneous and compact; The plating process had little impact on the mechanical properties of the aramid fiber, while the Ag-plating could enhance its thermal stability; The electrical resistivity is as low as 0.52 Ω/cm. And the Ag-layer exhibits good stability in hot- and cold-water cyclic test or in salt solution.

With capric acid (CA), lauric acid (LA), palmitic acid (PA), and myristic acid (MA) as raw materials, four kinds of ternary eutectic mixtures were prepared in consideration of the theoretical thermal property of the formed mixtures with the mass ratio of the three selected raw materials. Then LA-MA-PA/SiO₂ composite phase change materials were prepared by sol-gel method and their structure and performance were characterized. The results show that LA-MA-PA was uniformly filled into the three-dimensional network of SiO₂ and there was no chemical reaction between LA-MA-PA and SiO₂. LA-MA-PA/SiO₂ presented as smooth spherical particles with 3 μm in diameter, which exhibit smooth surface and good dispersibility. While the LA-MA-PA/SiO₂ exhibited high-performance in energy storage with little leakage even after 100 thermal cycling. The phase change temperature and latent heat of the LA-MA-PA/SiO₂ were determined to be 29.6℃ and 91.1 J/g.

Para-aramid fiber was modified with phosphoric acid (PA) and then was characterized by means of scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction(XRD). The mechanical behavior of the modified fiber (PPTA) was evaluated via measurement of the tensile strength and force-displacement curve of monofilament. The results show that the maximal fracture force of the modified fibers shifted to lower displacement region in force-displacement curves and the tensile strength of the monofilament decreased due to the damage of the skin region of PPTA fiber induced by PA-modification. Some aramid groups can be hydrolyzed during PA-modification process, thus decreasing the monofilament tensile strength of the modified PPTA fibers. In addition, the crystallinity of the modified fibers was improved because the original para-crystalline skin region was peeled off from the surface of PPTA fiber by PA-modification, hence resulting in the decrease of toughness of PA-modified fiber. The monofilament tensile strength of PPTA fiber decreased remarkably once it was modified with PA with concentration of higher than 40%(mass fraction), which can be attributed to the decrease of crystallinity.

The ceramic coating B-1000 was applied on the foamed electro-heating alloy NiCr20 through vacuum impregnation and high-temperature fusion sintering. The isothermal oxidation behavior at 1000℃ and thermal shock behavior between 1000℃ and 20 ^oC of the foamed electro-heating alloy with and without ceramic coating were investigated in air. The resistance to oxygen inward migration of the coating was evaluated by tensile test at 1000 ^oC in air. The results showed that the thin ceramic coating was uniform, dense, and well- adhesive to the substrate, which improved the oxidation resistance and thermal shock resistance of the foamed alloy NiCr20 significantly. The apparent tensile strength of the foamed electro-heating alloy NiCr20 with the coating B-1000 kept c.a. 2 MPa after air oxidation at 1000^oC for 20 h.

Composite films of regenerated silk fibroin/carboxymethyl chitosan were successfully prepared by quadratic freezing-drying method with glutaraldehyde as cross-linking agents, and then of which the physicochemical performance was characterized. The results show that the composite materials show a three-dimensional porous structure with uniform pore distribution; while there exists intermolecular hydrogen bonds between the silk fibroin and the carboxymethyl chitosan, thus they are compatible with each other; Among others, the prepared composite presents the best mechanical property and good thermal stability when the mass ratio of the regenerated silk fibroin to the carboxymethyl chitosan was 1:1 and the glutaraldehyde content was 0.20%. The composite material has also good biodegradability and biocompatibility.

ZnO nano-cones with various aspect ratios were synthesized via a solvothermal reaction of zinc acetate with n-butylamine and tetrahydrofuran or ethanol by varying dosage of n-butylamine and temperature. The possible growth mechanism was proposed. The products were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM) and ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS). Photocatalytic activity of ZnO nano-cones in degradation of methyl orange (MO) was investigated, and the results show that ZnO nano-cones show superior photoreactivity, compared to ZnO powders as a benchmarking. The superior intrinsic photocatalytic activity can be attributed to the high percentage of exposed {001} facets of ZnO nano-cones with small aspect ratio.

A visible-light catalytic composite material of regenerated cellulose supported SnS₂ (SnS₂/regenerated cellulose) was synthesized via microwave-assisted heating method at 120℃ with SnCl₄ and thioacetamide as the source of Sn and S respectively. The obtained SnS₂/regenerated cellulose was characterized by power X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-vis diffuse reflectance spectra (DRS) and specific surface areas (BET). The results show that the prepared SnS₂ is a phase with hexagonal crystal structure and the composite exhibited a nano-sized lamellar structure with 0.52 nm of interlayer spacing. In comparison with the simple SnS₂, the composite SnS₂/regenerated cellulose has larger absorption band for visible light and specific surface area. Furthermore, the microwave heating method can greatly reduce the synthesis temperature and the reaction time. The composite prepared at 120℃ for 20~80 min exhibited excellent photocatalytic performance. The removal efficiency for Rhodamine B (20 mg/L) can reach 100% within 3 h by the composite under visible light irradiation, and the degradation ratio of RhB can still reach 88% by the composite even after five cycles of use/regeneration.

Composites of SiC/h-BN ceramic were fabricated by pressureless sintering at 1700oC for 2 h. The sintered samples were alternately infiltrated with solutions of silica sol and phenolic in vacuum, and then pyrolyzed at 1450oC for 1 h. The density, flexural strength and Vickers hardness of SiC/h-BN composites before and after infiltration- and pyrolyzation-treatment were investigated, and the strengthening mechanism of the composites was analyzed. The results show that the relative density and mechanical properties of SiC/h-BN composites were improved significantly after infiltration- and pyrolyzation-treatment, as an example, the relative density of increased from 69.7% to 74.9%, and the flexural strength increased near 1.5 times for the composite SiC/20 mass% h-BN; XRD patterns and microstructure of the prepared composite revealed that the SiC particles formed during the pyrolyzation-treatment were nano-sized, which precipitated on the inner wall of pores of the sintered composite SiC/h-BN, Therewith, of which the resistance to crack propagation along grain boundaries was obviously increased, i.e., the mechanical properties of SiC/h-BN composite were improved.