Four Nb-Si based ultra-high temperature alloys with compositions of Nb-22Ti-16Si-4Hf-3Al-xCr (x = 0, 3%, 5% and 10%, atomic fraction) were prepared by vacuum non-consumable arc melting and then heat-treated at 1450℃ for 50 h. The effects of Cr content on the microstructure and room-temperature fracture toughness of the alloys were investigated. The results showed that the Cr addition did not change the crystal structure of the silicide γ(Nb, X)₅Si₃. The amount of γ(Nb, X)₅Si₃ rose while that of the eutectic Nbss/γ(Nb, X)₅Si decreased with the increasing Cr content. Furthermore, a low melting point of three-phase eutectic composed of Nbss, (Nb, X)₅Si₃ and Cr₂(Nb, X) was observed in Cr-containing alloys and its amount gradually increased with the increasing Cr addition. After 1450℃/50 h heat-treatment, the original Nbss dendrites as well as eutectic colonies disappeared, and the microstructural uniformity was significantly ameliorated. The alloys with 0, 3% and 5% Cr were all composed of phases Nbss and γ(Nb, X)₅Si₃, while three-phase equilibrium of Nbss, γ(Nb, X)₅Si₃ and Cr₂(Nb, X) was observed in the alloy with 10% Cr. However, the room-temperature fracture toughness of the as-cast alloys exhibited a decreasing trend with Cr addition.

Effect of heat treatment on the microstructure and mechanical properties of a high Nb-containing TiAl alloy sheet was investigated, which was fabricated by directly hot-rolling a packed alloy ingot. The obtained sheet mainly consisted of remnant coarsening lamella, recrystallized γ grains and strip-like β phase along rolling direction. Followed by variant heat treatments, the coarse lamella and β phase were eliminated, and various typical microstructures were appeared, such as duplex, near fully lamellar and fully lamellar ones. Mechanical properties of the sheet with duplex microstructure were tested at room and high temperatures respectively. The results showed that the strength and ductility of the sheet at room temperature were improved after heat treatment. The brittle-ductile transition temperature was in the range of 850-900℃, and the corresponding fracture mode transformed from transgranular fracture to the nucleation and coalescence of voids.

The Pt counter electrode was prepared on fluorine-doped tin oxide (FTO) glass by spin-coating and then thermal-decomposition of the precursor of H₂PtCl₆?6H₂O. The influence of the number of spin coating-annealing treatment on the amount of deposited platinum and light transmittance for the electrode, as well as the photovoltaic performance of dye sensitized solar cells assembled with the counter electrode was investigated. It was found that the optimal power conversion efficiency of 6.78% was obtained for cells assembled with Pt/FTO counter electrode after five spin coating-annealing treatments, which was higher than that of the cell assembled with the traditional counter electrode prepared by magnetron sputtering technique. Thereafter, the required concentration and volume of H₂PtCl₆?6H₂O precursor for the process could be further optimized in terms of the optimal number of spin coating-annealing and the amount of deposited platinum on the FTO glass counter electrode to ensure the best power conversion efficiency of dye sensitized solar cells. Furthermore, a novel Pt/FTO counter electrode was prepared by a one-step drop coating-annealing process, which exhibited high transmittance and low deposited platinum and then the power conversion efficiency could reach to 6.92% for cells assembled with such Pt/FTO counter electrode.

Nanoparticles of carbon encapsulated nickel (Ni@C NPs) were in-situ synthesized by direct current arc-discharge plasma method through evaporating pure Ni in methane atmosphere. Transmission electron microscopy observation revealed that the nanoparticles (Ni@C NPs) exhibited an encapsulation structure with Ni metal as core and carbon 3-5 nm in thickness as shell. The BET surface area of the prepared Ni@C NPs is 38.82 m²g^-1 according to N₂ adsorption-desorption isotherm. Surface modification with hydrogen peroxide was carried to graft oxygen-containing groups on carbon, which can improve the wettability and hydrophilicity of the Ni@C NPs. Then the effect of contact time, adsorption time and pH values on the adsorption of methylene blue was systematically investigated with the surface modified Ni@C NPs as adsorbent. The adsorption kinetics was analyzed with pseudo-first-order and pseudo-second-order models and the adsorption isotherm of methylene blue onto Ni@C NPs was fitted by Langmuir and Freundlich models. In addition, the result of recycling experiments for 5 cycles showed that a recovery rate 69.4% for the adsorbent could be reached. Furthermore, results of trial separation of Ni@C NPs by applied magnetic fields show that the magnetic field assisted separation technology is efficient means for the recycling and reuse of this adsorbent.

Phase change and humidity control composite materials of hexadecanol-palmitic acid-lauric acid/SiO₂ were prepared with SiO₂ as carrier material and hexadecanol-palmitic acid-lauric acid as phase change material. The effect of processing parameters on performance of humidity- and temperature-control of the composite materials was investigated by uniform design and multivariate nonlinear regression. The results show that their effect may be ranked as a sequence as follows: mole ratio of absolute alcohol to tetraethyl orthosilicate > solution pH value > mole ratio of hexadecanol-palmitic acid-lauric acid to tetraethyl orthosilicate > ultrasonic wave power > mole ratio of deionized water to tetraethyl orthosilicate. The optimal processing parameters are as follows: solution pH value 2.68, ultrasonic wave power 113 W, mole ratio of deionized water to tetraethyl orthosilicate 9.03, mole ratio of absolute alcohol to tetraethyl orthosilicate 5.22, mole ratio of decanoic-palmitic acid to tetraethyl orthosilicate 0.51.

A nickel-based (Ni⁰) composite coating, which was reinforced with 20%WC and 6% graphite particles and has a texture-like section morphology, was fabricated on steel substrate by vacuum cladding technology. Then its microstructure and tribological property under dry friction condition were characterized in comparison with other three coatings (Ni⁰, Ni⁰+20%WC and Ni⁰+6% graphite). The results show that the WC particles evenly distributed in the nickel-based (Ni⁰) alloy coatings and formed a special 3D reticular microstructure. The Ni-based alloy coating is mainly composed of γ-Ni solid solution, hard phases (Cr₇C₃, Cr₂₃C₆, CrB) and eutectic phases (Ni₃Si, Ni₃B). The cladd composite coating consisted of Ni⁰ with WC and graphite particles exhibits the highest wear resistance among the test coatings. The combination of texture-like structure (which was composed of WC particles and nickel base alloy) and graphite lubricant promoted the abrasion resistance of the composite coating by about 9.6 times in comparison to the pure Ni⁰ coating.

Copolymer AKPM-g-PAN was prepared by copolymerization of maleic anhydride grafted krill protein (AKP) and polyacrylonitrile (PAN), then AKPM-g-PAN composite fibers were prepared by wet spinning, whilst there mechanical and thermal properties were investigated. The results show that: the best condition for preparation of AKPM-g-PAN are: the ratio of AKP, maleic anhydride and PAN is 2: 2: 12.5, the initiator is 10% (mass fraction) PAN, and the reaction temperature is 60℃. The molecular weight of the polymer obtained after grafting polymerization by the optimal process condition was 158010. The fracture strength of AKPM-g-PAN composite fibers increased with increasing concentration of spinning solution, whilst increases first and then decreases with the increase of the concentration and temperature of the coagulation bath; and the addition of AKP leads to increase of water retention rate of composite fiber, influencing polyacrylonitrile original regularity of molecular chain, and lost of a part of crystallization ability.

Composites 45 steel/T2 copper and 304 Stainless steel/T2 copper were prepared by high-temperature vacuum casting. The interface bonding strength, microstructure, microhardness and composition change of the phase boundary zone of the composites were investigated by SEM observation, EDS analysis, XRD and mechanical property test. The results show that interdiffusion occurred of alloy elements Fe, Cr and Cu of the two substrates resulting in formation of phases such as a new iron carbon compounds (CFe_15.1) and solid solution Cu_0.81 Ni_0.19, and Cr-Ni-Fe-C, there existed a dentate interdiffusion layer of about 60 to 70 microns without obvious intermetallics in the transition zone and its microhardness is about 183 and 119HV for 45-T2 and 304-T2 respectively; tensile/shear strength of the composite are 278/263MPa and 217/201 MPa respectively for 45/T2 and 304/T2; break occurs in the copper side with typical ductile fracture characteristics. Cu element plays an important role in improvement of the stability and strength of the substrates 304 stainless steel and 45steel.

Cross-linked gelatin has been prepared using ferulic acid as cross-linking agent in a previous article. The moisture sorption isotherm of the cross-linked gelatin was determined gravimetrically at 25℃. The gel strength and the viscosity of solutions with different concentrations of cross-linked gelatin were determined by texture analyzer and Ubbelohde viscosimeter, respectively. The results show that for the salt saturated solutions with the same water activity, the equilibrium moisture content of the cross-linked gelatin is slightly lower than that of the non cross-linked gelatin in the solutions with low water activity, but the former is slightly higher than the latter when the water activity is high. The moisture sorption isotherm data were mathematically fitted to the GAB model. The critical concentration of the cross-linked gelatin solution to form gel is 0.7% g/mL, which was similar to that of the non cross-linked gelatin solution. Above the critical concentration, the gel strength of the cross-linked gelatin increases with the increase of its concentration, but it is obviously lower than that of the non cross-linked gelatin for the same concentration. The intrinsic viscosity of the cross-linked gelatin is 354.38 mL/g, but that of the non cross-linked gelatin is 85.80 mL/g.

The compatibility between 2 modifiers Styrene-Butadiene-Styrence Block Copolymer (SBS) and Sasobit and 70#A base asphalt was comparatively studied by means of solubility calculation, measurement of difference of segregation softening point, differential scanning calorimetry and atomic force scanning microscope. The results show that the solubility parameter can not reflect the influence of molecular weight on polymer compatibility, due to the asphalt and modifiers all have multiphase structures with high molecular weight, a complex structure should be expected for the bland of the asphalt and a modifier. The compatibility of the modified asphalt can not be simply evaluated as a whole by Hildebrand theoretical calculation formula. Adding Sasobit into base asphalt can not only increase the glass transition temperature of the base asphalt, but also change the shape of its endothermic peak curve significantly, so Sasobit has good compatibility with base asphalt. However, adding the two modifiers SBS and Sasobit can greatly reduce the compatibility between modifier and base asphalt.

For the influence of stress ratio on fatigue life, fatigue tests of TC18 titanium alloy produced by build-up welding (TC18 by BW) samples were carried out under three stress ratios (R=0.5、R=0.06、R=-1), to draw three fatigue limits and 6 S-N curves of “stress amplitude life model ” and “ three-parameter model ”. Based on the integral relationship of the crack growth rate and fatigue life and considering both of mathematical models of fatigue life, a systematic investigation of the relationship between stress ratio (R) and fatigue life curve (S-N) was performed to build the fatigue life mathematical model (R-S-N). According to the modified formula proposed in this paper, the establishment of two R-S-N mathematical models, applicable for TC18 by BW materials. The results show that “stress amplitude” model can accurately predict moderate fatigue life, and “three-parameter fatigue” model is more suitable for the prediction of long-life area. The predictive value of two proposed R-S-N mathematical models are in better agreement with the experimental values, they can accurately predict the fatigue curve under any stress ratio in engineering.