The MIC behavior of 2205 duplex stainless steel (2205 DSS) caused by the marine Pseudomonas aeruginosa (P. aeruginosa) with different soaking time was investigated through electrochemical testing techniques. Results show that the surface of 2205 DSS plate presents a microstructure composed of continuous ferrite matrix with uniformly distributed elongated islets of austenite phase with (111) preferred orientation. The open circuit potential E_OCP, polarization resistance (R_p), and charge transfer resistance (R_ct) measured in the sterile medium were larger than those in the P. aeruginosa inoculated medium during the whole soaking period of 7 d, indicating that P. aeruginosa accelerated the corrosion of 2205 DSS; The maintaining passivity current density (i_p) of the 2205 DSS increases with the immersion time in both sterile and P. aeruginosa inoculated medium, whilst, the value of which during immersion in the bacterial solution was higher than that in the sterile solution for 1 d, 3 d, and 7 d respectively, the fact further proved that P. aeruginosa accelerated the corrosion process of 2205 DSS; Scanning electron microscopy (SEM) results show that the amount of bacteria adhering to the steel surface gradually increased with the immersion time in the bacteria solution. After soaking for 3 days, the bacteria on the steel aggregated to form small clusters, and the bacteria aggregated to form a bacterial biofilm after 7 days. The bacterial biofilm accelerates the occurrence of pits, and later resulting in severe localized corrosion. X-ray photoelectron spectroscopy (XPS) results revealed that the water soluble CrO₃ could form on the 2205 DSS surface in the P. aeruginosa inoculated medium, which may be the inducement responsible to the MIC related pitting corrosion.

Microstructure and high temperature tensile properties of five powder metallurgy FGH98 alloys with different Ta content were systematically investigated by optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscope (TEM) and high temperature tensile testing machine. The results show that: Ta can obviously eliminate the prior particle boundaries (PPB) and change the morphology of secondary γ'-phase. Ta can promote the generation of tertiary γ'-phase. Ta improved the high temperature tensile strength and yield strength of the alloys. When the Ta content was 2.4% (the same below), the alloy has the preferable plasticity. Alloys without Ta and with 1.2%Ta showed a crystalline-like fracture surface while the alloy with 2.4%Ta showed ductile fracture surface. Alloys with 3.6%Ta and 4.8%Ta exhibited transgranular and intergranular cleavage fractures. The alloy without Ta deformed mainly by generating a large number of twins and dislocations bypassing the γ'-phase. With the increasing Ta content, the dislocations shear the γ'-phase, therewith produce a large number of stacking faults.

Ti6Al4V (TC4) alloy was prepared by vacuum sintering of the pressed powder mixture of TiH₂, Ti and Al-V alloy. The effect of sintering temperature on the phase constituents, microstructure , density and mechanical properties of the alloy was characterised by XRD, metallography, mechanical tests and SEM fracture morphology. The result shows that the prepared alloy composed of hexagonal α-Ti phase and body-centered cubic β-Ti phase. The alloy presents a microstructure with equiaxed grains, as well as mesh basket or lath (lamellar and acicular) like structures. With the increase of sintering temperature and holding time, the equiaxed grains gradually disappeared, while the amount of lamellar- and acicular-like structures increase and which then were coarsened . The alloy sintered at 1150℃ presents a microstructure with better mesh basket like structures. TC4 Ti-alloyswith relative density of 96.9%~99.6%, tensile strength of 719.3~914.1 MPa, elongation at break of 6.2%~-9.4% and hardness of 313.2~364.8 HV can be obtained by the method. Among others, the alloy with the best mechanical property could be acquired by sintering at 1150℃, which shows tensile strength of 914.1MPa, elongation at break of 7.6% and hardness of 355.5 HV respectively. The fracture morphology was mainly ductile for the alloy prepared by sintering of powder mixture of Ti and pure TiH₂ , and it gradually turns into brittle-tough mixed fracture with the increasing amount of Al-V alloy powder was added, correspondingly, the tensile strength of the prepared alloys increased but the elongation at break decreased.

Porous high-N austenitic stainless steel was fabricated via powder metallurgy and its microstructure and properties were investigated. Results show that high temperature nitridation process promotes the phase transformation of the stainless steel from duplex phase to austenitic phase. Precipitations with different morphologies were observed in the microstructure. XRD results and TEM results identified that both the two precipitates with different morphologies are all CrN phase. With the increasing pore-forming agent the porosity of the prepared alloy increased, which could result in degradation of mechanical properties and corrosion resistance. The superior mechanical property of porous alloys fabricated by this method might be ascribed to the effect of solid solution strengthening of the solute N and precipitation strengthening of nitrides. With the increasing porosity, both of the corrosion tendency and corrosion rate increased for the as-fabricated porous high-N austenitic stainless steel. Among others, the alloy with 10% (mass fraction) pore former exhibits the best corrosion resistance. Besides, the increase of sintering temperature can enhance the densification of the as-prepared alloy, thus improves its corrosion resistance.

A lead-carbon battery, which possesses simultaneously advantages of lead-acid battery and supercapacitor, can be obtained by adding a certain amount of carbon into the lead-acid battery. So, it is particularly critical to create a new type of carbon with ideal specific capacitance and stability in acid solutions. We tried to synthesize such a new carbon material namely C-ZIF-8@AC via a two step process i.e. low temperature liquid phase method and high temperature calcination. The materials were characterized by field emission scanning electron microscope (FESEM), high resolution transmission electron microscope (HRTEM), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectrometer (FTIR) etc. The results show that the prepared C-ZIF-8@AC composed of carbon particles with polyhedral structure (ZIF-8 framework) grown uniformly on the surface of active carbon (AC) particles; After ZIF-8 has further been coupled with AC particles, the size of the formed C-ZIF-8 particles is reduced. Electrochemical results indicate that the elemental N in pyridine nitrogen and pyrropyrrole nitrogen of the C-ZIF-8 framework can enhance the specific capacitance of C-ZIF-8@AC, which is about 181 F/g, much higher than that of the simple AC. The C-ZIF-8@AC shows excellent cycling stability with 99% capacitance retention rate after 6000 cycles at the current density of 5 A/g, which is higher than that of the simple AC.

The composite materials of continuous Al₂O_3f/ZL210A alloy with 40% of Nextel610-Al₂O₃ fiber were fabricated via vacuum-pressure infiltration process, while the fiber was preheated at temperatures of 500, 530, 560 and 600℃, respectively before pressure-infiltration. The effect of fiber preheating temperature on the microstructure and mechanical properties of the composites of continuous Al₂O_3f/ZL210A alloy was investigated. The results show that the density of composites increases with the increase of fiber preheating temperature; Among others, the composite of continuous Al₂O_3f/ZL210A made out of the fiber Al₂O_3f preheated at 600℃ presents the highest density of 99.2%; The tensile strength of Al₂O₃ fibers extracted from the prepared composites depends significantly on their preheating temperature, namely the higher preheating temperature may results in the lower tensile strength, as an example, the extracted Al₂O₃ fiber, which was subjected to pre-heat treatment at 600 C, presents a rough surface morphology with tensile strength of only 1150 MPa; The fiber preheating temperature has a significant effect on the tensile strength of continuous Al₂O_3f/Al composites. Indeed, the composites fabricated with Al₂O₃ fibers, which were preheated at 500, 530, 560 and 600℃ respectively, possess corresponding tensile strength of 298, 465, 498 and 452 MPa. The existed defects and damages on fibers, as well as the interfacial reaction between fibers and the matrix may be the main factors affecting the strength of the composites of continuous Al₂O_3f/ZL210A alloy.

The electrochemical performance of lithium-ion capacitors with stabilized lithium metal powder/multi-walled carbon nanotubes composite as anode and activated carbon as cathode was investigated by means of galvanostatic charge/discharge (GCD) tests and electrochemical impedance spectroscopy (EIS). The results show that the introduction of stabilized lithium metal powder can eliminate the majority of the inherent irreversible capacity of carbon nanotubes and greatly improve the electrochemical performance of lithium-ion capacitors. The lithium-ion capacitors have a specific capacitance of 85.18 F/g at the current density of 0.05 A/g. The maximum energy density and power density reached 140.4 Wh/kg and 5.25 KW/kg respectively in the current range of 0.05~4 A/g. The continuous galvanostatic charge-discharge cycling tests revealed that the lithium-ion capacitors could maintain 82% of the capacity after 3000 cycles. In sum, the lithium-ion capacitors showed an excellent cycle performance with high energy and power density.

Three polymer fibers were prepared via electrospinning method with polyacrylonitrile (PAN), polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP) respectively as raw materials, and then carbon fibers with porous morphology were obtained by carbonizing the above three polymer fibers in nitrogen gas. The physical-chemical properties of the obtained carbon fibers were characterized by means of X-ray diffractometer, IR spectroscopy, thermal analysis and N₂ adsorption-desorption isotherm. The results show that the PAN-based carbon fiber has the largest specific surface area of 113.5 m²/g and the maximum adsorption capacity of about 560.2 g/kg on Congo red; Meanwhile, the effect of temperature and pH values on the adsorption properties of carbon fibers was also investigated. The results demonstrate that the higher the temperature is, the faster the adsorption rate is, while there is no significant change in the adsorption capacity; With the varying pH value of Congo red containing solutions, the three carbon fibers presented different adsorption performance: namely, in acidic solutions the PVA-based carbon fibers can maintain a high adsorption capacity, while the behavior of the PAN-based carbon fiber is just the opposite, however, the varying pH value of the Congo red solution had little effect on the adsorption activity of the PVP-based carbon fiber.

Carbon nanotubes of different proportions were added to the cement matrix to prepare cement-based materials, and the thermal expansion property of those materials was measured from room temperature to 600°C. While the materials were characterized by means of DSC/TG, XRD, pore size distribution diagrams, SEM images. The results show that the thermal expansion rate is positive from room temperature to 150°C, there is a slight expansion; the thermal expansion rate is negative and gradually decreases from about 150°C to 590°C, the specimen shrinks continuously. When the blending amount of carbon nanotubes is 0.3%, the thermal expansion curve is always below those with the amounts other than 0.3%, and the thermal expansion rate reaches a minimum value. This shows that when the amount of carbon nanotubes is 0.3%, the hydration reaction is sufficient and a large amount of hydrous calcium silicate gel is produced, and the shrinkage is obvious and the density is significantly improved. Therefore, the content of 0.3% carbon nanotubes can effectively prevent the emerge of abnormal expansion of local area for a heating pipe and therefore, improve the durability of the structure.

Red phosphor nanoparticles YVO₄:Eu³⁺,Bi³⁺ have been successfully prepared via a facile hydrothermal method with Y₂O₃, Eu₂O₃, HNO₃, Bi(NO₃)₃·H₂O, NH₄VO₃, NH₃·H₂O, HNO₃, EtOH and diethylene glycol (DEG) as raw materials and polyvinyl pyrrolidone (PVP) as accessory ingredient. The as-prepared products were characterized by XRD, SEM, IR and PL. The results show that, all the samples are well crystallized and assigned to be the tetragonal crystal structure as the YVO₄ phase. Their microstructure varied with the pH value of solutions. The YVO₄:Eu³⁺, Bi³⁺ nanoparticles exhibit simultaneously orange (at 594 nm) and red (at 619 nm) emissions. The broad orange-red emissions can be attributed to the ⁵D₀→⁷F₁ and ⁵D₀→⁷F₂ transition of Eu³⁺ ion in YVO₄ matrix. As the ratio of Eu³⁺/Bi³⁺ increases, the fluorescence intensities increase first and then weaken, while reach the strongest red emission at n_Eu³⁺/n_Bi³⁺=5. Besides, the pH value presents influence on the intensities of the YVO₄:Eu³⁺, Bi³⁺ nanoparticles to some extent. The YVO₄:Eu³⁺, Bi³⁺ nanoparticles prepared in the solution with pH = 10 exhibits the strongest red emission. Finally, the mechanism related with the Bi³⁺→Eu³⁺ energy transfer in YVO₄:Eu³⁺, Bi³⁺ nanoparticles was also discussed.