The capacity fade of spinel lithium manganese oxide in lithium-ion batteries is a bottleneck challenge for the large-scale application. The traditional opinion is that Mn(II) ions in the anode are reduced to the metallic manganese that helps for catalyzing electrolyte decomposition. This could poison and damage the solid electrolyte interface (SEI) film, leading to the the capacity fade in Li-ion batteries. We propose a new mechanism that Mn(II) deposites at the anode hinders and/or blocks the intercalation/de-intercalation of lithium ions,which leads to the capacity fade in Li-ion batteries. Based on the new mechanism assumption, a kind of new structure with core-shell characteristic is designed to inhabit manganese ion dissolution, thus improving electrochemical cycle performance of the cell. By the way, this mechanism hypothesis is also supported by the results of these experiments. The LiMn_2-xTi _xO₄ shell layer enhances cathode resistance to corrosion attack and effectively suppresses dissolution of Mn, then improves battery cycle performance with LiMn₂O₄ cathode, even at high rate and elevated temperature.

The electronic structures of bulk Bi₂Te₃ crystals were investigated by the first-principles calculations. The transport coefficients including Seeback coefficient and power factor were then calculated by the Boltzmann theory, and further evaluated as a function of chemical potential assuming a rigid band picture. The results suggest that p-type doping in the Bi₂Te₃ compound may be more favorable than n-type doping. From this analysis results, doping effects on a material will exhibit high ZT. Furthermore, we can also find the right doping concentration to produce more efficient materials, and present the “advantage filling element map” in detail.

Triangular-pyramidal ω-Bi₂O₃ is successfully synthesized via a one-step wet-chemical method. XRD, SEM, and UV-vis have been employed to characterize the as-prepared samples. Structural characterization by XRD confirms the formation of triclinic ω-Bi₂O₃ with high purity. The well-defined flower-like Bi₂O₃ structures consisted of many triangular-pyramids are formed. Preparative parameters, such as concentration of PEG 6000, have great effects on the morphology and the particle size. The obvious absorption edge for ω-Bi₂O₃ powder is located at about 493 nm, which corresponds to the optical band gap energy of 2.73 eV.

We prepared a series of glass samples under the different simulated atmosphere. Systematic evaluation about the performances of the glasses fabricated under the different simulated atmosphere indicates that the increase of the H₂O:CO₂ ratio under the simulated atmosphere will decrease the softening point temperature, microhardness, viscosity, and chemical resistance, while increase the thermal expansion coefficient. Through the analysis of the hydroxyl content and network structure according to the IR transmitting spectra and NMR spectra, the structural origin of the evolution of the performances for the samples fabricated under different simulated atmosphere was elucidated. According to the feedback information from the customers, despite the decrease of some performances, the glass produced under oxy-fuel combustion can also fulfill the requirements of the engineering applications. Therefore, the technique of oxy-fuel combustion is worthy to be promoted in glass industry.

Metal-organic framework (MOF) material MIL-53(Al) with high thermal stability was prepared by a solvothermal method, serving as a support material of cerium doped copper catalyst (Ce-Cu)/MIL-53(Al) material for CO oxidation with high catalytic activity. The catalytic performance between the (Cu-Ce)/MIL-53(Al) and the Cu/MIL-53(Al) catalytic material was compared to understand the catalytic behavior of the catalysts. The catalysts were characterized by thermogravimetric-differential scanning calorimetry (TG-DSC), N₂ adsorption- desorption, X-ray diffraction (XRD), and transmission electron microscopy (TEM). The characterization results showed that MIL-53(Al) had good stability and high surface areas, the (Ce-Cu) nanoparticles on the MIL-53(Al) support was uniform. Therefore, the heterogeneous catalytic composite materials (Ce-Cu)/MIL-53(Al) catalyst exhibited much higher activity than that of the Cu/MIL- 53(Al) catalyst in CO oxidation test, with 100% conversion at 80 °C. The results reveal that (Cu-Ce)/MIL- 53(Al) is the suitable candidate for achieving low temperature and higher activity CO oxidation catalyst of MOFs.

The Ag/Mg_0.2Zn_0.8O/ZnMn₂O₄/p⁺-Si heterostructure devices were fabricated by sol-gel spin coating technique and the resistive switching behavior, conduction mechanism, endurance characteristic, and retention properties were investigated. A distinct bipolar resistive switching behavior of the devices was observed at room temperature. The resistance ratio R _HRS/R _LRS of high resistance state and low resistance state is as large as four orders of magnitude with a readout voltage of 2.0 V. The dominant conduction mechanism of the device is trap-controlled space charge limited current (SCLC). The devices exhibit good durability under 1×10³ cycles and the degradation is invisible for more than 10⁶ s.

The MoS₂ microspheres with high specific surface area assembled by ultrathin nanosheets have been successfully synthesized by a facile and environmentally friendly reaction in a closed reactor at moderate temperatures. The solid-state assembly was realized by a simple calcination process, and the annealing temperature played a key role in the formation of the final microspheres. The influences of reaction temperature were carefully investigated. A possible formation mechanism about the solid-state assembly was proposed based on the experimental results.

Na₂O-Al₂O₃-SiO₂ glass-ceramics doped with Er³⁺ ions were synthesized by the conventional melt quenching technique at a low melting temperature. The samples were characterized by differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-vis-NIR scanning spectrophotometry, and fluorescence spectrometry. The results show that the main crystalline phase of glass-ceramics is nepheline.The best heat-treatment process is at 520 °C for 2 h. Because the up-conversion luminescence and near infrared luminescence properties of glass doped with Eu³⁺ are studied in detail.

Fe₃O₄/carbon nanotubes (Fe₃O₄/CNTs) nanocomposites were prepared by polylol high-temperature decomposition of the precursor ferric chloride and CNTs in liquid triethylene glycol. After surface modification with hexanediamine, folate was covalently linked to the amine group of magnetic Fe₃O₄/CNTs nanocomposites. The products were characterized by Fourier-transform infrared spectroscopy, transmission electron microscopy, and vibrating sample magnetometry. Then Fe₃O₄/CNTs were used as a dual-drug carrier to co-delivery of the hydrophilic drug epirubicin hydrochloride and hydrophobic drug paclitaxel. The results indicated that the Fe₃O₄/CNTs had a favorable release property for epirubicin and paclitaxel, and thus had potential application in tumor-targeted combination chemotherapy.

Multi-walled carbon nanotubes (MWNTs) were incorporated into precursor-derived ceramics made from a polysilazane. A ceramic nanocomposite reinforced with about 35 vol% of carbon nanotubes (CNTs) was fabricated by infiltrating CNT-preform with liquid-phased polymeric precursor followed by pyrolysis. The nanocomposite has a dense structure without micro-cracks. The results reveal that the nanocomposite has lower indentation hardness but higher fracture energy than non-reinforced ceramic from the microindentation tests results. The effect of the CNTs on the mechanical properties of the nanocomposite should be discussed accordingly.

Good fluidity (low viscosity) of highly concentrated kaolin is highly needed in paper-coating industry. We put forward an effective route to improve the viscosity concentration of Beihai kaolin slurries. The effects of various factors such as solid content, pH, dispersant content, and urea-intercalation on the viscosity of kaolin slurries were investigated. The results revealed that the viscosity of kaolin slurries significantly decreased with decreasing solid content or with increasing pH and dispersant content. It was worth noting that urea-intercalation was proven to be an efficient method for promoting the dispersion of highly concentrated kaolin as compared with adding dispersant. The intercalation ratio of urea-intercalated kaolin was increased from 17.36% with 2% of urea addition to 81.30% with 6% of urea addition. Meanwhile, the viscosity concentration of raw kaolin slurry was improved from 65.0% to 70.13% after the intercalation of urea with 6% addition, which was attributed to finer particle size, increased pH value and more negative charges of urea-intercalated kaolin. Therefore, the route is effective to improve the dispersion of highly concentrated kaolin for paper-coating.

Effects of rare earth oxides (Y₂O₃, La₂O₃, and Er₂O₃) on the viscosity, thermal expansion, and structure of alkali-free boro-aluminosilicate glasses were investigated by the rotating crucible viscometer, dilatometry and FT-IR absorption spectra. The results showed that the melting temperature of alkali-free boro-aluminosilicate glasses decreased from 1 697.55 to 1 662.59, 1 674.37 and 1 640.87 °C with the introduction of 1 mol% La₂O₃, Y₂O₃ and Er₂O₃, respectively. However, the glass transition temperature T _g, dilatometric softening temperature T _d and coefficient of thermal expansion of alkali-free boro-aluminosilicate glasses increased when adding the rare-earth oxides. At high temperatures, incorporating rare earth oxides into glass resulted in the peak at about 1 085 cm^-1 towards lower wavenumber and the absorption band in the region of 850-1 260 cm^-1 broader, which indicated that rare earths acted as network modifiers and increased the numbers of non-bridging oxygen in the glass melts. However, the rare earths had an opposite effect and accumulated the glass structure at low temperatures near T _g.

Chemical co-precipitation method was used to synthesize tin-doped indium oxide (ITO) nanoparticles, and the subsequent solution co-blend was employed to fabricate ITO/PVB nanocomposites. UV(Ultra-violet)-Vis(Visible)-NIR( Near Infrared) spectra show that the addition of ITO nano particles can significantly enhance the thermal insulating efficiency of ITO/PVB nanocomposites. With increasing ITO content, the thermal insulating efficiency is increased. UV is almost fully absorbed by all ITO/PVB nanocomposites. Vis transmittance-haze spectra reveal that ITO/PVB nanocomposites exhibit higher Vis transmittance over 71.3% and lower haze below 2% when ITO content is in the range of 0.1 wt%-0.7 wt%. The UV-Vis -NIR spectroscopy shows that, under the premise of over 70% transmittance to the visible light, the screening effect of the NIR can be enhanced by 80% with 0.7% ITO/PVB nanocomposite membrane compared with the undoped PVB. The thermal insulating tests indicate that, in comparison with the pure PVB film, nanocomposite films with 0.1 wt%-0.9 wt% ITO can reduce temperature by 3-8 °C. The results show that this novel nanocomposite can be used for energy-saving glass.

Ag loaded mesoporous silica-embedded TiO₂ nanocomposites were successfully synthesized via two different routes, including one-pot solvothermal method and solvothermal-chemical reduction method, both using Titanium (IV) n-butoxide (Ti(OC₄H₉)₄) as a precursor, formic acid as a solvent and reducing agent, silver nitrate as a silver source and tetraethyl silicate (TEOS) as a stabilizer. The transmission electron microscopic (TEM) images showed that silica-embedded anatase TiO₂ sample exhibited approximately rhombic shape and Ag nanoparticles could be embedded into the nanocomposites or deposited on the surface with high dispersion. The N₂ adsorption-desorption isotherms indicated that the silica-embedded anatase TiO₂ had obvious mesoporous structure with a BET specific surface area of 203.5 m²·g^-1. All Ag loaded silica-embedded TiO₂ composites showed a higher photocatalytic H₂-generation activity from water splitting under simulative solar light irradiation than that of TiO₂ products. The maximum H₂ production rate (6.10 mmol·h^-1·g^-1) was obtained over 2% Ag/silica-embedded TiO₂ nanocomposites (2% Ag/MST) prepared by solvothermal-chemical reduction method, which was 20 times that achieved on the silica-embedded TiO₂ sample. The enhanced photocatalytic H₂-evolution activity of Ag loaded mesoporous silica-embedded TiO₂ nanocomposites can be attributed to the multi-function of surface Ag co-catalyst, mesoporous structure, and embedding of silica.

The diffusion property of sulfur on the soda-lime-silicate float glass surface was studied by using secondary ion mass spectroscopy(SIMS). According to the Fick`s Second Law, two models of diffusion of sulfur on the glass surface were built. When the diffusion of sulfate (S⁶⁺) is considered uniquely, the concentration-depth profile of sulfur can not be fitted very well, especially on the top surfaces of the air side and tin side of float glass. So the diffusion of sulfide (S^2-) on the profile of sulfur can not be ignored. The concentration-depth profile of sulfur on both sides of glass can be fitted more exactly when both S⁶⁺ and S^2- are considerd. Based on the above-mentioned fitting results, it is concluded that the diffusion coefficents of S⁶⁺ and S^2- of tin side are larger than those of the air side. Moreover, the diffusion coefficents are related to the contacted medium.

The cobalt sulfide/graphene oxide (CoS/GO) nanocomposite was synthesized by a simple hydrothermal reaction. The products as-synthesized were characterized by XRD, SEM, TEM, BET-BJH and TG. The electrochemical property and impedance of the CoS/GO nanocomposite were studied by cyclic voltammetry and EIS analysis, respectively. The results show that the presence of the GO enhances the electrode conductivity, and then improves the capacitance property of the CoS/GO nanocomposite. The galvanostatic charge/discharge measurement results show that the CoS/GO nanocomposite has a high specific capacitance (550 Fg^-1) and long cycle life (over 1 000 cycles).

Al-doped zinc oxide (AZO) and Ga-doped zinc oxide (GZO) thin films with the same doping concentration (3.6 at%) were deposited on glass substrates at room temperature by direct current (DC) magnetron sputtering. Consequently, we comparatively studied the doped thin films on the basis of their structural, morphological, electrical, and optical properties for optoelectronic applications. Both thin films exhibited excellent optical properties with more than 85% transmission in the visible range. The GZO thin film had better crystallinity and smoother surface morphology than the AZO thin film. The conductivity of the GZO thin film was improved compared to that of the AZO thin film: the resistivity decreased from 1.01 × 10^-3 to 3.5 × 10^-4 Ω cm, which was mostly due to the increase of the carrier concentration from 6.5 ×10²⁰ to 1.46 × 10²¹ cm^-3. These results revealed that the GZO thin film had higher quality than the AZO thin film with the same doping concentration for optoelectronic applications.

A series of Sr_1–1.5xY _xTiO₃ (x = 0–12) solid solutions were synthesized by a solid state reaction process. The effects of reaction temperature and dopant on the crystallinity, microstructure and morphology of Sr_1–1.5xY _xTiO₃ (x=0–0.12) were investigated. Pure and single-phase perovskite-type Sr_1–1.5xY _xTiO₃ (x<0.08) solid solutions were obtained at 1 400 °C for 6 h. The perovskite-type SrTiO₃ and pyrochlore-phase Y₂Ti₂O₇ coexisted for x = 0.08–0.12, leading to an unstable and unfavourable solid solution structure for long-term immobilization of the ⁹⁰Sr. The X-ray diffraction patterns for Rietveld refinement analysis confirmed the formation of a Sr_1–1.5xY _xTiO₃ (x = 0–0.12) continuous solid solution. Stretching and bending vibrations were assigned in the infrared region. The SrTiO₃ grain size increased with Y content. The leaching behavior of Y³⁺ from the waste forms of Sr_1–1.5xY _xTiO₃ was controlled by its structural change.

Al _xO _y films by DC reactive magnetron sputtering were annealed in air ambient at 500 °C for 1 h with different heating rates of 5, 15, and 25 °C/min.Then heat treatments at 900 °Cwere carried out on these 500 °C-annealed films to simulate the high-temperature application environment. Effects of the annealing heating rate on structure and properties of both 500 °C-annealed and 900 °C-heated films were investigated systematically.It was found that distinct γ-Al₂O₃ crystallization was observed in the 900 °C-heated films only when the annealing heating rates are 15 and 25 °C/min. The 500 °C-annealed film possessed the most compact surface morphology in the case of 25 °C/min. The highest microhardness of both 500 °C-annealed and 900 °C-heated films were obtained when the annealing heating rate was 15 °C/min.

We put forward a first-principles density-functional theory about the impact of pressure on the structural and elastic properties of bulk CaN₂, SrN₂ and BaN₂. The ground state properties of three alkaline earth diazenides were obtained, and these were in good agreement with previous experimental and theoretical data. By using the quasi-harmonic Debye model, the thermodynamic properties including the debye temperature Θ _D, thermal expansion coefficient α, and grüneisen parameter γ are successfully obtained in the temperature range from 0 to 100 K and pressure range from 0 to 100 GPa, respectively. The optical properties including dielectric function ε(ϖ), absorption coefficient α(ϖ), reflectivity coefficient R(ϖ), and refractive index n(ϖ) are also calculated and analyzed.

The influences of different nano–SiO₂ (NS) contents on the mechanical properties and rheological behavior of sulfoaluminate cement (SAC) based composite materials were studied. Results show that with increasing content of NS, the apparent viscosity, and shearing strength of fresh paste gradually increase but the fluidity decreases. With a dosage of 3.0% NS, the tensile and flexural strengths of mortars at 56 days were increased by 87.0% and 84.6%, respectively, compared with that in the absence of NS, indicating that the toughness of hardened mortars is significantly improved. Besides, the exothermic peaks of hydration are obviously increased and will earlier occur, and the second and the third peaks appear 2.61 hours and 2.56 hours earlier, respectively than that in the absence of NS, and the hydration of SAC before 8 hours is accelerated. The forming mechanism of strengths was revealed by scanning electron microscopy (SEM), hydration heat, X-ray diffraction (XRD) and derivative thermogravimetry (DTG). The micro-aggregate filling effect and nucleation effect at early age and weak pozzolanic effect at late age of NS make the microstructure more compact, which obviously enhances the strength of SAC mortars.

Using the detection principle of infrared thermal imaging technique and the detection principle of DRH thermal conductivity tester laboratory, we investigated the infrared thermal image inspection, coefficient of thermal conductivity, apparent density, and compressive strength test on C80 high-strength concrete(HSC) in the presence and absence of polypropylene fibers under completely heated conditions. Only slight damages were detected below 400 °C, whereas more and more severe deterioration events were expected when the temperature was above 500 °C. The results show that the elevated temperature through infrared images generally exhibits an upward trend with increasing temperature, while the coefficient of thermal conductivity and apparent density decrease gradually. Additionally, the addition of polypropylene fibers with appropriate length, diameter, and quantity contributes to the improvement of the high-temperature resistance of HSC.

Acid rain can deteriorate the performance of reinforced concrete structure. Combined with the characteristics of acid rain in China, the properties of steel fiber reinforced concrete subjected to acid rain were studied. The effects of steel fiber content and pH value of acid rain on the mass loss, erosion depth, neutralization depth, and splitting tensile strength of tested concrete were investigated. The mercury intrusion pore (MIP) test was used to analyze the influence of steel fiber on the acid rain resistance of concrete matrix. The results show that the corrosion of steel fiber reinforced concrete subjected to acid rain results from the combined effect of H⁺ and SO₄ ^2- in the acid rain, and steel fiber can improve the acid rain resistance of the tested concrete by improving the pore structure and enhancing the tie effect of the concrete matrix. The experiment further indicates that the optimum content of steel fiber is 1.5% compared to the various mixing proportion in this tests. The tested concrete mass loss and splitting tensile strength decrease followed by increasing as a function of corrosion time when the pH value of the simulation solution is 3 or 4, while they decrease continuously in the simulation solution at pH 2. Thanks to the tie effect of steel fiber, the spalling of concrete matrix is significantly improved, and the erosion depth and neutralization depth are less than those of conventional concrete.

The aim of this study is to provide the quantificational change laws of strength, stiffness, and deformation capacity of frost-damaged concrete relating to a united index, the data were obtained by different researchers. Then the index of relative compressive strength (RCS) was introduced as the indicator of frost damage and a large number of mechanical performance testing data of frost-damaged concrete were collected and analyzed. By curve fitting, the correlations between RCS and the initial elastic modulus, the strain at peak compressive stress, and biaxial compressive strength, and tensile strength, and the strain at peak tensile stress were established. Thereafter, the analytical stress-strain response of frost-damaged concrete under monotonic loading was presented using RCS and compared with that of the experimental data. Moreover, an isotropic elastoplastic damage model of frost-damaged concrete subjected to repeated loading was established. Finally, we can systematically estimate the effects of frost-damage on the mechanical performance of concrete, which can be provided for the numerical simulation of frost-damaged concrete structures.

Carbon nanotubes (CNTs) were synthesized by the electric heating catalytic chemical deposition method (CCVD) using acetylene (C₂H₂) as the carbon source and nitrogen (N₂) as carrier gas, and nickel catalyst was loaded by electroplating. The electric heating method, as a new method, electrifies the carbon fiber directly by using its conductivity. The morphology and structure of CNTs were characterized by SEM and TEM, and the surface properties of carbon fibers before and after the growth of CNT were characterized by Raman spectroscopy. The experimental results show that the electric heating method is a new method to produce CNT, and can grow a large number of CNTs in a short time, the crystallization degree and surface average crystallite size of carbon fiber increased after the growth of CNT on it. In addition, electroplating loading catalyst can also be used as an ideal loading way, which can control the number, shape, and distribution of nickel particles by controlling the plating time.

Ti/Cu/N coatings with different Cu contents were deposited on titanium alloy surface by the DC magnetron sputtering technique. XPS and FESEM were employed to characterize the composition and structure of the coating on the Ti6Al4V substrates. In addition, The adhesion force, friction, and wear properties of the Ti/Cu/N coatings were investigated. The experimental results showed that the coarse particles of the coatings would grow more and the surface roughness increased with the increase of copper content in the coatings; The coatings showed a strong adhesion force; The friction coefficient of the coating of the samples was less than the substrate, reaching 0.19 at least. The wear resistance of the coatings could be improved by optimizing and controlling the relative content of Ti, Cu, N elements on the titanium alloy surface, especially the 10.98 at% contents of the copper. The sample C2 kept the best wear resistance.

The development of lead-free solders has emerged as one of the key issues in the electronics packaging industries. Bi-Sn-Ag eutectic alloy has been considered as one of the lead-free solder materials that can replace the toxic Pb-Sn eutectic solder without increasing soldering temperature. We investigated the effects of temperature gradient and growth rate on the mechanical, electrical and thermal properties of the Bi-Sn-Ag ternary eutectic alloy. Bi-47 wt%Sn-0.68 wt%Ag alloy was directionally solidified upward with different temperature gradients (G=2.33-5.66 K/mm) at a constant growth rate (V=13.25 μm/s) and with different growth rates (V=6.55-132.83 μm/s) at a constant temperature gradient (G=2.33 K/mm) in the growth apparatus. The microstructures (λ), microhardness (HV), tensile stress (σ), electrical resistivity (ρ), and thermal properties (ΔH, C _p, T _m) were measured on directionally solidified samples. The dependency of the λ, HV, σ, and ρ on G and V was investigated. According to the experimental results, λ values decrease with increasing G and V, but HV, λ, and ρ values increase with increasing G and V. Variations of electrical resistivity (ρ) for cast samples with the temperature in the range of 300-400 K were also measured by using a standard dc four-point probe technique. The enthalpy of fusion (ΔH) and specific heat (C _p) for the same alloy was also determined by means of differential scanning calorimeter (DSC) from heating trace during the transformation from eutectic liquid to eutectic solid.

The fatigue behavior during high cycle fatigue testing and the tensile behavior of 5A06 aluminum alloy considering the anisotropy were studied. Two types of specimens including longitudinal specimen (parallel to the rolling direction) and transverse specimen (perpendicular to the rolling direction) were prepared. Infrared thermography was employed to monitor the temperature evolution during the fatigue and tensile tests. The temperature evolution curves in the two directions were contrastively analyzed. It is found that the temperature evolution during fatigue process possesses four stages: initial temperature rise stage, slow temperature decline stage, rapid temperature rise stage, and finial temperature decline stage. The heat generating mechanisms of the four stages are discussed. Obvious differences can be found between the longitudinal specimen and transverse specimen in fatigue strength and fatigue life. The fatigue strength and fatigue life of longitudinal specimen are higher than those of transverse specimen. During the tensile and fatigue testing process, the fracture temperature in the transverse direction are higher than that in the longitudinal direction. The fatigue strength prediction by means of infrared thermography has a good consistency with that by the traditional method.

The hot deformation behaviors of two medium carbon ultra-high strength steels with different niobium contents were investigated by using Zener-Hollmom parameter and processing map, and the effect of niobium addition on the hot deformation behavior of medium carbon steel was determined. The hot compression tests were conducted on a Gleeble-3500 thermo-mechanical simulator deformed at temperatures from 850 to 1 200 °C and strain rates from 0.001 to 1 s⁻¹. The processing maps of two test steels were built at a true strain of 0.7 based on dynamic materials model (DMM). There are two peak efficiency domains and two flow instability regions in both test steels. However, the peak efficiency domains of Nb-bearing steel move to higher temperature due to the inhibition of dynamic recrystallization (DRX), and the instability domains of Nb-bearing steel are enlarged due to the precipitation of Nb-containing particles during hot deformation. The optimum process parameters of Nb-bearing and Nb-free steels for industrial production were determined according to the processing map and the microstructural observation.

The passive film-induced stress and the susceptibility to SCC of 7050 aluminum alloy in 3.5% sodium chloride solution at various pH values were investigated by slow strain rate testing (SSRT) and flowing stress differential method. The results showed that the passive film-induced stress and the susceptibility to SCC decreased with increasing pH values when pH≤7, while they increased with increasing pH values when pH >7. However, the corrosion type was interpreted as exfoliation corrosion when pH=1 and 14, and there was no film formed on the surface of the specimens. The whole variation plots of film-induced stress and the SCC susceptibility with pH values were both presented as a valley shape. The symbol and amount of the film-induced stress were related to the compositions of the passive film, which were analyzed using X-ray photoelectron spectroscopy (XPS).

To improve the bioactivity and corrosion resistance of AZ91D magnesium alloy, hydroxyapatite (HAp) coatings with novel microstructured morphologies were prepared successfully on AZ91D substrates via a facile hydrothermal method. Different chelating agents including polyaspartic acid (PASP) and ethylenediaminetetraacetic acid (EDTA) were introduced to investigate their effects on the morphology and corrosion resistance of the coated magnesium alloys. The results revealed that the coating prepared with PASP was composed of many uniform urchin-like microspheres, while the coating prepared with EDTA consisted of many flower-like particles. Moreover, the crystallinity of the coating prepared with EDTA was much higher than that of the coating prepared with PASP. Electrochemical tests revealed that the corrosion resistance of the substrate was significantly improved after being coated with each coating. Immersion test of the coated samples in simulated body fluid (SBF) demonstrated that the coatings could be biodegraded gradually and induce the formation of calcium phosphate particles.

Two kinds of Mn-Si-Mo low carbon steels were designed to study the effects of Mn on the microstructures and properties of hot rolled low carbon bainitic steels. To reduce the production cost, a very low Mo content of 0.13% was added in both steels. After hot rolling, the mechanical properties of samples were tested. Microstructure was observed and analyzed by optical microscope and transmission electron microscope. The results show that the strength of tested steels increases with the increase in Mn content, while the elongation decreases. When Mn content increases, the bainite microstructure increases. The results can provide a theoretical basis for composition design and industrial production of low cost low carbon bainitic steels.

Multilayer iridium coating was manufactured on tungsten carbide substrates by a double glow plasma process. As comparison, monolayer was also produced. The microstructure and morphology were observed using scanning electron microscopy. Grain orientation and phase were determined using X-ray diffraction. The residual stress of the coating was studied by glancing incidence X-ray diffraction. The adhesive force of the coating was measured by a scratch tester. The results showed that both monolayer and multilayer had a polycrystalline phase with a strong (110) reflection. The coating had an excellent adhesion with no evidence of delamination. The adhesive force of the monolayer and multilayer was about 50 and 43 N, respectively. The interfacial reaction between the substrate and the layer occurred and a new WIr phase was found due to the high-temperature deposition process. The residual stress in the monolayer and multilayer was -1.6 and -1.1 GPa, respectively.

Fly ash floating bead (FAFB) was modified by the nonionic surfactant polyethylene glycol (PEG) under various concentrations to improve its hydrophobility, and then PEG modified FAFB composited with polyaniline (FAFB-PEG/PAn) by emulsion polymerization method using different feed ratios of FAFB-PEG. The chemical structure, phase structure, microstructure, conductivity, and dielectric properties were studied by FT-IR, XRD, SEM, four-probe technique, and LCR digital bridge, respectively. It was demonstrated that the optimal concentration of PEG was 1 mol/L and the corresponding grafting ratio was 1.42 %. The phase structure of FAFB was not destroyed after modification by PEG, while the surface became smoother and could be coated by PAn successfully according to SEM technique. Compared to that of dodecylbenzenesulfonic acid doped PAn (PAn-DBSA), the conductivity of FAFB-PEG/PAn was decreased by 10-100 times after introduction of various amounts of FAFB-PEG, especially the value could be decreased to 0.01 S cm^-1 if 50 wt% of FAFB-PEG was provided. Additionally, the dielectric constant and loss factor of FAFB-PEG/PAn composites gradually decreased with increasing amount of FAFB-PEG in the frequency range of 100 KHz-2 MHz, namely, the dielectric constant could be still kept at 500 and correspondingly the loss factor decreased to 4.7 at 100 KHz if 50 wt% of FAFB-PEG was provided. The leaking current phenomenon derived from PAn-DBSA could also be weakened by FAFB-PEG.

Layered organic-inorganic hybrids (C _nH_2n+1NH₃)₂(CH₃NH₃) _m-1Pb _mI_3m+1 containing monolayer (m=1) and bilayer (m=2) perovsikte were synthesized by reactions in solution. The influences of the reactant ratio, solvent, reaction temperature, and reaction time on the structures of the products were investigated. The structures and the properties of the hybrids were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and ultraviolet and visible (UV) absorption spectroscopy. The XRD patterns and the SEM images demonstrate that the pure bilayer perovskite hybrids are obtained. The UV-vis spectra indicate that the number of the inorganic perovskite layer (m) has greater impact on the band gap than the number of the carbon atoms (n). The band gap of bilayer hybrids (around 1.9 eV) is significantly less than that of monolayer hybrids (around 2.2 eV).

Using the ab initio plane-wave ultrasoft pseudopotential method based on generalized gradient approximation (GGA), we investigated the band-gap tuning in monolayer phosphorene (MLP) and bilayer phosphorene (BLP) by external electric fields applied perpendicular to the layers. The band continuously decreases with increasing applied electric fields, eventually rendering them metallic. For MLP, the phenomenon is explained in the light of the giant Stark effect, which is essentially characterized by the interlayer spacing, for the rate of change of bandgap with applied external field. The atomic distance and charges also contribute to the semiconductor-metal transition. The BLP is more sensitive to electric fields than MLP, since their charges are rearranged among bilayers and the bandgap can dramatically drop in terms of electronic field. The results show the bandgap will change for the fabrication of novel electronic and photonic devices.

Cell surface of aquatic organisms constitutes a primary site for the interaction and a barrier for the nano-TiO₂ biological effects. In the present study, the biological effects of nano-TiO₂ on a unicellular green algae Chlamydomonas reinhardtii were studied by observing the changes of the cell surface morphology and functional groups under UV or natural light. By SEM, the cell surface morphology of C. reinhardtii was changed under UV light, nano-TiO₂ with UV light or natural light, which indicated that photocatalysis damaged cell surface. It was also observed that cell surface was surrounded by TiO₂ nanoparticles. The ATR-FTIR spectra showed that the peaks of functional groups such as C-N, -C=O, -C-O-C and P=O, which were the important components of cell wall and membrane, were all depressed by the photocatalysis of nano-TiO₂ under UV light or natural light. The photocatalysis of nano-TiO₂ promoted peroxidation of functional groups on the surface of C. reinhardtii cells, which led to the damages of cell wall and membrane.