A new method for preparing SiC particle-reinforced aluminum matrix composites was introduced. In order to improve the ingot surface and homogeneity of structure, low frequency electromagnetic field was applied during the direct chilling casting process. The experimental results show that the new method can be used to prepare SiC particle-reinforced aluminum matrix composites; under the effects of the low frequency electromagnetic field, the microstructure of ingot is refined and the distribution of SiC particles is improved.

In order to establish a simple, sensitive, and fast reliable detection method to determine the magnolol, FeWO₄ nanoflower was synthesised through a solvothermal technique and FeWO₄ nanoflower modified carbon paste electrode (CPE) was developed. The voltammetric behavior of magnolol on the modified electrodes was studied using cyclic voltammetry (CV), linear sweep voltammetry (LSV), and differential pulse voltammetry (DPV). The experimental results showed that the modified electrode remarkably enhanced the electrochemical response of the magnolol and exhibited a wide linear range for determination of the magnolol from 1.0×10^-7 to 1.0×10^-4 mol/L with a low detection limit of 5.0×10^-8 mol/L.

Amorphous La_0.7Zn_0.3MnO₃ (LZMO) films were deposited on p⁺-Si substrates by sol-gel method at low temperature of 450 °C. The Ag/LZMO/p⁺-Si device exhibits invertible bipolar resistive switching and the R _HRS/R _LRS was about 10⁴-10⁶ at room temperature which can be kept over 10³ switching cycles. Better endurance characteristics were observed in the Ag/LZMO/p⁺-Si device, the V _Set and the V _Reset almost remained after 10³ endurance switching cycles. According to electrical analyses, the conductor mechanism was in low resistor state (LRS) governed by the filament conductor and in the high state (HRS) dominated by the traps-controlled space-charge-limited current (SCLC) conductor.

WO₃ nanowires were fabricated by a hydrothermal method, which proceeded at 170 °C for 48 h in a solution containing C₂H₁₀N₆H₂SO₄ as a dispersant and Na₂WO₄ as a starting material. The nanowires exhibit a well crystallized one-dimensional structure with 20 nm in diameter and several microns in length. The physicochemical properties of WO₃ were compared using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX) and UV-vis spectroscopy (UV-Vis). The photoactivity of the as-perpared WO₃ nanowires was evaluated through the photodegradation of methylene blue (MB) in aqueous solution. The experimental results demonstrate that addition of C₂H₁₀N₆H₂SO₄ salt in the WO₃ nanowires synthesis process can enhance its photocatalytic activity obviously.

Gold nanoparticles (GNPs) modified hierarchical meso-macroporous (HMMP) SiO₂ layer on the surface of Au film electrode was developed as a novel enzyme immobilization matrix for biosensors construction. HMMP SiO₂-Au bilayer film electrodes were in-situ fabricated with magnetron sputtering process and templating method. The as-prepared HMMP SiO₂ films were characterized by SEM, TEM, and cyclic voltammetry (CV). The modified layer of HMMP SiO₂ has interconnected pore channels, and the sizes of macropores and mesopores are about 330 nm and 9 nm, respectively. The HMMP SiO₂ modified gold film electrodes not only have no diffusion barrier for electrochemical probes, but also exhibit good electrochemical properties. In addition, the activity and stability of the immobilized enzyme can be commendably retained in HMMP SiO₂. The biosensor exhibits an excellent bioelectrocatalytic response to glucose with a linear range of 1.0×10^-4 M-1.0×10^-2 M, high sensitivity of 18.0 μA·mM^-1·cm^-2, as well as good reproducibility and stability.

A hybrid material of carbon microspheres (CMSs) with Ag decoration (Ag/CMSs) was developed. Poly (3-hexylthiophene):Ag/CMSs composite film was prepared by spin-coating. Scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectrometry, X-ray diffraction, thermogravimetric analysis and cyclic voltammetry were employed to analyze the morphologies, structures, thermal properties and energy levels of Ag/CMSs. The optical property of the composite films was characterized by ultraviolet-visible spectrophotometry and fluorescent spectrometry. The results indicate that silver nanoparticles (Ag NPs, d = 10-20 nm) are distributed on the surface of CMSs. LUMO and HOMO energy levels of Ag/CMSs are -3.97 and -5.52 eV, below the vacuum energy level, respectively, indicating that it is feasible to use Ag/CMSs as an electron acceptor. Ag NPs are blended into the active layer to trigger localized surface plasmon resonance, and consequently enhance light harvesting. The coupling of surface plasmons and excitons increased the probability of exciton dissociation.

A novel poly(methyl-methacrylate)/silica aerogel (PMMA/SA) dual-scale cellular foam was synthesized with internal mixing followed by the supercritical carbon dioxide foaming process. The effects of silica aerogel content on the microstructural and mechanical performance of the foams were investigated by SEM, TEM analysis, and mechanical tests. The experimental results suggest that the employment of silica aerogel granule as addictive can distinctly improve the morphological feature as well as the mechanical performance in comparison to neat PMMA foam by uniformizing cell size distribution, decreasing cell size and increasing cell density. And dual-scale cells including micrometric cells of 3-10 μm and nanometric cells of about 50nm existed in the structure of foams resulting from the retained original framework structure of silica aerogel, which has not been described in other studies with the addition of various fillers. Furthermore, the mechanical strength was significantly elevated even with a small amount of silica aerogel resulting from the unique microstructure, decreased cell size and enhanced cell walls. The compressive strength was 18.12 MPa and the flexural strength was 18.90 MPa by adding 5wt% and 2wt% silica aerogel, respectively. These results demonstrate the potential to synthesize PMMA/SA dual-scale cellular foams to be used as structural materials with the advantages of low density and high strength.

The influence of surface state on the moisture sensitivity of carbon fiber was analyzed by applying a T800 grade carbon fiber with five different surface conditions, namely, with and without surface oxidation, in the presence or absence of sizing agent. The interfacial properties of their composites in the presence of two epoxy matrices (respectively EP07 and EP10) were also characterized by micro-droplet tests. The overall results show that both oxidized and sizing-coated fibers have higher moisture equilibrium content than that of the pristine unsurface-treated fiber, due to higher amount of activated carbon groups. After moisture absorption of the carbon fibers, almost all the fiber/epoxy systems show decrease in the interfacial shear strength and the unsurface-treated fiber system exhibits the largest decline. Moreover, both interfacial shear strength and interlaminar shear strength of carbon fiber/EP10 composite demonstrate better water resistance performance than that of the carbon fiber/EP07 composite, consistent with DSC results of the two resins.

Novel Bi₂S₃/BiOCl photocatalysts were successfully synthesized via a facile biomolecule-assisted solvothermal method and biomolecule L-cysteine was used as the sulfur source. The structures, morphology, and optical properties of the synthesized samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, transmission electron microscopy (TEM), and UV-vis diffuse reflectance spectroscopy (DRS). The presence of Bi₂S₃ in the Bi₂S₃/BiOCl composites could not only improve the optical properties but also enhance the photocatalytic activities for the degradation of Rhodamine B (RhB) under visible-light irradiation (λ > 420 nm) as compared with single Bi₂S₃ and BiOCl. Especially, the sample displayed the best performance of the photodegradation when the feed molar ratio of BiCl3 and L-cysteine was 2.4:1, which was about 10 times greater than that of pure BiOCl. The enhanced photocatalytic activities could be ascribed to the effective separation of photoinduced electrons and holes and the photosensitization of dye. Moreover, the possible photodegradation mechanism was also proposed, and the results revealed that the active holes (h⁺) and superoxide radicals (•O₂ ⁻) were the main reactive species during photocatalytic degradation.

The Mg/MoS₂ composites were prepared by ball milling under argon atmosphere, and the effect of MoS₂ on the crystal structure and hydrogen storage properties of Mg was investigated. It is found that 10 wt% of MoS₂ is sufficient to prevent particle aggregation and cold welding during the milling process. The crystallite size of Mg will remain constant at slightly less than 38.8 nm with the milling process due to the size confinement effect of MoS₂. The dehydrogenation temperature of MgH₂ is reduced to 390.4-429.4 °C due to the crystallite size reduction. Through fitting by Johnson-Mehl-Avrami model, it is found that Mg crystal grows by three dimension controlled by interface transformation during the process of MgH₂ decomposition. MoS₂ has a weak catalyst effect on the decomposition of MgH₂ and activation energy of 148.9 kJ/mol is needed for the dehydrogenation process calculated by the Arrhenius equation.

With Al foil, Cu foil and steel mesh as the metal interlayers, respectively, three types of alumina/epoxy/metal laminated composites were fabricated with epoxy resin adhesive as a binder via a simple process. The impact tests were performed and the fracture patterns and impact response of all the three laminates were analyzed. The experimental results indicate that the absorbed energy is mainly determined by metal interlayer. The peak load depends on not only alumina substrate but also metal interlayer. The Al₂O₃/epoxy/Cu laminates sustain the maximum peak load and Al₂O₃/epoxy/steel mesh laminates have the largest threshold energy for penetration. The fracture analysis shows that the main damage modes are Al₂O₃ matrix cracking and metal deformation for lower impact energies, and complete breakage and penetration for higher impact energies.

(1-x)CaTiO₃-xNi_0.5Zn_0.5Fe₂O₄ (0 ≤ x ≤ 1.0) composite ceramics were synthesized by a conventional solid state reaction method. The phase formation, microstructure, and dielectric and magnetic properties were investigated by X-ray diffraction, scanning electron microscopy, precision impedance analysis, and vibrating sample magnetometry, respectively. The results indicate that the composite ceramics are composed of both perovskite phase CaTiO₃ and spinel phase Ni_0.5Zn_0.5Fe₂O₄. The maximal relative density for 0.5CaTiO₃-0.5Ni_0.5Zn_0.5Fe₂O₄ composite ceramics reaches 97.8%, as it has been sintered at the temperature of 1260 °C for 3 h. Dielectric constant and loss tangent of (1-x)CaTiO₃-xNi_0.5Zn_0.5Fe₂O₄ composite ceramics show dispersion in the low frequency range. Their phase transition temperature of the dielectric constant shifts to lower temperatures with the increase of Ni_0.5Zn_0.5Fe₂O₄ content. This phenomenon is attributed to that the phase transition temperature of CaTiO₃ is higher than that of Ni_0.5Zn_0.5Fe₂O₄. The saturation magnetization of (1-x)CaTiO₃-x Ni_0.5Zn_0.5Fe₂O₄ composite ceramics increases with the Ni_0.5Zn_0.5Fe₂O₄ ferrite content.

BiVO₄ photocatalysts were synthesized by a surfactant free hydrothermal method without any further treatments, and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS), Raman spectroscopy, and Brunauer-Emmett-Teller (BET) surface area techniques. The photocatalytic activity was evaluated for the degradation of the methylene blue (MB) under visible light irradiation. Seen from the structural and morphological characterization, it is stated that the obtained samples present monoclinic phase, and the pH value has significant influence on the morphologies. The enhanced photocatalytic performance was associated with its crystallinity, unique morphology, band gap energy, BET specific surface area, surface charge and adsorption capacity. The recycle experiments results show that the BiVO₄ photocatalysts have excellent photo-stability, and we deduced a possible mechanism by examining the effects of the active species involved in the photocatalytic process for MB photocatalytic degradation.

Using Ba(OH)₂·8H₂O as phase change material (PCM) and water as heat transfer fluid (HTF), we numerically simulated annular finned-tube heat exchangers. In order to measure and analyze the impact of parameters in the heating/cooling process, temperature changes of different monitoring points, fin widths, and fin pitches as key parameters were considered and applied. The experimental results show that the heat exchange process can be divided into three stages within a certain time. The faster heat transfer rate is associated with the greater temperature difference between PCM and HTF. Furthermore, fins width and pitch affect dramatically the heat charging/discharging rate. The large fins width or small fins pitch is beneficial for extending the heat exchange surface, leading to improve heat transfer efficiency.

We studied the effects of sintering temperature on FeCuCo based pre-alloyed powder for diamond bits. The FeCuCo composite was fabricated by co-precipitation method. With the addition of tungsten carbide (WC), sintering under different temperatures was investigated. Mechanical properties of the FeCuCo based matrix were systematically studied. The structure of the composite was evaluated by X-ray diffraction (XRD) and scanning electron microscope (SEM) was used to analyze the surface of the powder and matrix. The suitable sintering temperature was determined through differential scanning calorimeter (DSC). Micro drilling experiments were performed, and 820 °C was identified to be the ideal sintering temperature, at which the matrix shows the best mechanical properties and drilling performance.

We prepared Pb-0.3wt%Ag/Pb-WC (WC stands for tungsten carbide, the same below) composite inert anodes by double-pulse electrodeposition on the surface of Pb-0.3wt%Ag substrates, and investigated the electrochemical properties of the composite inert anodes, which were obtained under different forward pulse average current densities from 2 A/dm² to 5 A/dm² and WC concentrations from 0 g/L to 40 g/L in bath. The kinetic parameters of oxygen evolution, corrosion potential and corrosion current of the composite inert anodes were obtained in a synthetic zinc electrowinning electrolyte of 50 g/L Zn²⁺ and 150 g/L H₂SO₄ at 35 °C, by measuring the anodic polarization curves, Tafel polarization curves and cyclic voltammetry curves. The results show that Pb-0.3wt%Ag/Pb-WC composite inert anodes obtained under forward pulse average current density of 3 A/dm² and WC concentration of 30 g/L in an original acid plating bath, possess higher electrocatalytic activity of oxygen evolution, lower overpotential of oxygen evolution, better reversibility of electrode reaction and corrosion resistance in [ZnSO₄+H₂SO₄] solution. The overpotential of oxygen evolution of the composite inert anode is 0.926 V under 500 A/m² in [ZnSO₄+H₂SO₄] solution, and 245 mV lower than that of Pb-1%Ag alloy; the corrosion current of the composite inert anode is 0.95×10^-4 A which is distinctly lower than that of Pb-1%Ag alloy, showing the excellent corrosion resistance.

A new corona protection varnish was prepared by using epoxy/montmorillonite nano-composite and pure epoxy resin as adhesives respectively. The adhesive with different amounts of organic montmorillonite (OMMT) was mixed with 1200 mesh silicon carbide (SiC) by different weight ratios. The surface states of the varnishes with various adhesives were observed by powerful optical microscope. Some properties of the varnishes were analyzed during the enduring time under 5kV/cm DC, such as the relation of change in nonlinear coefficient, natural surface resistivity, and surface temperature variation. The results showed that the amounts of OMMT had little effect on the natural surface resistance of the varnish but had important influence on the nonlinear property of the varnish. When the range of the OMMT content was 2wt% to 6wt%, the nonlinear coefficient of all materials with epoxy/OMMT nano-composite adhesive was higher than that with pure epoxy resin adhesive. The surface temperature of the varnish with epoxy/OMMT nanocomposite adhesive was all lower than that with the pure epoxy resin adhesive under high electrical field strength.

Carbon nanoparticles (C-dots) were prepared by refluxing the combustion soots of candles and corn stalk in nitric acid. The synthesized C-dots were characterized. The results showed a sharp increase in oxygen content and a sharp decrease in carbon content after oxidation. The C-dots had -OH and -CO₂H groups introduced which made them hydrophilic. However, their difference was also obvious. The C-dots from candle soot had a 10-45 nm broad particle size distribution, and those from corn stalk soot had a 6-18 nm relatively small and narrow size distribution. The C-dots were mainly of sp ² and sp ³ carbon structure different from the C-dots of diamond-like structure from candle soot. Interestingly, two kinds of C-dots all exhibited unique photoluminescent properties. The obtained C-dots have potential applications in a broad range of areas.

The synthesis of Nd³⁺, Y³⁺:CaF₂ nanopowder was conducted by azeotropic distillation method, which effectively dehydrated hydrous CaF₂ and prevented forming hard agglomerates. X-ray diffraction (XRD), scanning electron microscopy (SEM), scanning calorimetries-thermalgravimetry (DSC-TG), Fourier transform infrared spectroscopy (FT-IR) and absorption spectroscopy were performed to characterize the powder properties. The experimental results showed that products obtained by azeotropic distillation were single phased, rather monodispersed, successfully prevented the hard agglomerate formation and effectively removed the residual water inside the as-prepared precipitate than that of the direct drying. The absorption spectra showed a wider and stronger absorption bands around 792 nm, which should be profitable for LD pumping.

ZnO-B₂O₃-SiO₂-Al₂O₃-Na₂O glass doped with nucleating agent TiO₂ was prepared with melting-quenching method and the effect of nucleating agent on the crystallization behavior and phase evolution of this glass was investigated by differential thermal analysis (DTA), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The experimental results show that the glass transition temperature and the first crystallization temperature decrease from 630 °C and 765 °C to 595 °C and 740 °C, respectively, with introduction of TiO₂ into glass. There is no diffraction peaks in the XRD pattern but it is no longer transparent for the base glass without nucleating agent after heat treatment, which suggests the serious phase separation occurred, and the observation by SEM indicates that the phase separation is developed by nucleation and growth mechanism. However, there are two different crystals ZnAl₂O₄ and NaAlSiO₄ present in the glass containing TiO₂ after heat treating at 575 °C for 2 h and 740 °C for 6 h, respectively. What is interesting is that NaAlSiO₄ disappears as the crystallization time at 740 °C increases from 6 h to 12 h, and more ZnAl₂O₄ crystal is formed, namely, the further formation of ZnAl₂O₄ is at cost of NaAlSiO₄ with increasing crystallization time. And observation of the morphology of glass ceramics shows great difference with increasing crystallization time. Moreover, the ability of ZnO-B₂O₃-SiO₂-Al₂O₃-Na₂O glass ceramics against attacking of 1M HCl solution is increased by the crystals precipitated in heat treatment process.

Spark plasma sintering (SPS) was used to weld the ceramics, eg, Cr₃C₂ and metal, Ni in this paper. It is found that the SPS can weld the Cr₃C₂ and Ni plates at lower temperatures and shorter holding time comparing with that of hot-pressing (HP). The binding strength was 113 MPa when the temperature was 1000 °C by SPS, compared with 10 MPa by HP at the same temperature. SPS remarkably enhances the atom diffusion in welding.Thermodynamics analysis at different welding temperatures and holding times of SPS or HP shows that the local temperature gradient, different from the past effects of by-passing current, is the dominative mechanism of the SPS welding.

The dynamic shear modulus G of soil was determined using a dynamic triaxial test system (DTTS) together with a fitting method. First, a novel linear relationship between G and damping ratio λ was proposed, which was used to select the appropriate G. Then, a hyperbolic model was constructed using the optimized parameters a and b representing the intercept and slope, respectively, from the linear regression of 1/G and dynamic shear strain γ _d. Finally, the differences between the tested and predicted results for G were analyzed for different soil types. The experimental results show that this linear relationship can overcome the shortcomings of the nonlinear relationship found in the large deformation stage and can predict λ in the hysteresis loop that is not closed case. In addition to Baoji loess, G was slightly larger (10%) than the experimental curve in the elasto-plastic stage; however, the experimental results show that the attenuation curve of G for Baoji loess is greater than the calculated value in the elasto-plastic stage. The test and analysis results will improve the knowledge of the dynamic properties of soils and also provide reliable values of G for further evaluation of seismic safety at engineering sites.

In order to study the size effect on the AE rate ‘a’ value, three kinds of mix ratios were set up by different particle sizes and water cement ratios, 45 cement mortar specimens with five different heights were tested under axial compression. And the whole damage processes were monitored by full-digital acoustic emission acquisition system, followed by an analysis of mechanical behavior and AE activity. The experimental results show that the height of the cement specimen has significant effects on the compressive strength and the acoustic emission rate ‘a’ value, but a slight effect on the accumulated AE hits number, which is analyzed from aspects of failure process of cement mortar specimens.

Service life of reinforced concrete structures usually was designed on the basis of one selected deteriorating mechanism as for instance carbonation, chloride penetration, and frost action. It could be shown in the meantime by numerous authors, however, that combined actions such as chloride penetration under mechanical load or chloride penetration in combination with freeze-thaw cycles may shorten the service life of reinforced concrete structures more than individual processes acting alone. We have found that chloride penetration is accelerated significantly by freeze-thaw cycles. Frost damage not only reduces mechanical strength and elastic modulus but migration of chloride is facilitated in the damaged pore structure. Chloride penetration can be retarded by the addition of silane emulsion to the fresh concrete. In this way Integral Water Repellent Concrete (IWRC) can be produced. Migration of water and ions dissolved in water can not be prevented by integral water repellent treatment but it is slowed down. The combination of damage mechanisms and the protective measures by integral water repellent treatment have to be taken into consideration in realistic service life prediction and design.

Based on the erosion resistant coefficient, the effects of water-cement ratio, air-entrained, silica fume content and sand ratio on the sulfate attack resistance of air-entrained silica fume concrete were studied by orthogonal experiments in order to explore its sulfate attack resistance under dry-wet condition. A more significant model of concrete resistance to sulfate attack was also established, thus this work provided a strategy reference for quantitative design of sulfate attack resistant concrete. The experimental results show that dry-wet cycle deteriorates the concrete resistance to the sulfate attack, and leads to the remarkable declines of concrete strength and sulfate resistance. Air bubbles in the air-entrained silica fume concrete lower and delay the damage resulted from the crystallization sulfate salt. However this delay gradually disappears when most of the close bubbles are breached by the alternative running of the sulfate salt crystallization and the permeating pressure, and then the air bubbles are filled with sulfate salt crystallization. The concrete is provided with the strongest sulfate resistance when it is prepared with the 0.47 water-binder ratio, 6.0% air-entrained, 5% silica fume and 30% sand ratio. The erosion resistant coefficients K ₈₀ and K ₁₅₀ of this concrete are increased by 9%, 7%, 9%, and 5% respectively as compared with those of concretes without silica fume and air entraining.

Three different types and sizes of coarse aggregate were chosen, and the alternating current (AC) impedance of cement paste samples with and without aggregate was measured at different curing ages. Based on Song’s equivalent circuit model, the electrical properties from the AC impedance results were obtained, and the resistance of connected pores RCCP was used to characterize the microstructure of the interfacial transition zone (ITZ). The results show that the RCCP of concrete sample with aggregate is lower than that of cement paste sample, which indicates that the introduction of aggregate in cement paste makes the ITZ porous. Furthermore, for the same type of aggregate, an increase in particle size leads to a more porous ITZ, which accounts for the “water effect” and a larger aggregate would accumulate a thicker water film around it. In addition, for the same size of aggregate, the physical interaction between aggregate and cement paste is dominant in early age, and the microstructure of the ITZ around limestone aggregate is denser, which mainly depends on its rough surface and high water absorption. However, the microstructures of the ITZ around granite and basalt aggregates are denser in later age, which may be due to their higher chemical activity, and the chemical interaction between them and cement paste resulting in the generation of more hydrates. AC impedance spectroscopy thus proves to be powerful for evaluation of the microstructure of the ITZ.

The corrosion of ECR glass fiber was investigated by the analysis methods of weight loss ratio under different acids and at various durations. Weight loss, leaching of cations, and surface composition of ECR glass fiber were analyzed. The corrosion mechanism of ECR glass fiber in acid environment was also discussed. The experimental results showed that the corrosion degree of ECR glass fiber in different acids obeyed the order: HNO₃>H₂SO₄>HCl. The acid effects on corrosion of ECR glass fiberis were totally different. Hydrochloric acid mainly destroyed the network structure of [AlO₄], while sulfuric acid and nitric acid mainly destroyed the structure of [SiO₄]. The acid resistance of ECR glass fiber is much better than that of E glass fiber due to the generation of intermediate product silicic acid gel Si(OH)₄ during ion exchange. It can adhere to the glass surface to form a thin film and hinder the proceeding of corrosion.

The total utilization amount of red mud is limited due to its high content of alkali, heavy metals and naturally occurring radioactive element. In order to rationalize the use of red mud, a typical field road cement using dealkalized red mud (content of alkali lower than 1%) as raw material was firstly prepared in this paper. Then, a preliminary research on the radioactivity of the red mud based field road cement has been carried out. For that reason, two samples of raw materials were prepared. One was with ordinary raw materials, as the control group (CG), the other was with 23w % red mud, as the experimental group (EG). The clinkers were acquired by sintering the above two raw materials at 1 400 °C. Subsequently, the two types of cement prepared by the above two kinds of clinkers were tested by measuring the normal consistency, setting time, mechanical strength and drying shrinkage. Meanwhile, the hydration products of the two types of cement were examined by XRD analysis at the curing age of 6 hours, 1, 3, 7, and 28 days, respectively. The radioactivity of the two kinds of cement clinkers was then measured by gamma-ray spectrometry. The experimental results indicate that the main mineralogical phases components in the EG field road cement clinkers are C₃S, C₂S, and C₄AF, the 28 days flexural and compressive strength of the EG field road cement mortars could be up to 8.45 and 53.2 MPa, respectively. The radioactive measuring results of the EG field road cement show that the value of radium equivalent activity index (Ra_eq) is 254.8 Bq/Kg^-1, which is lower than the upper limit.

The aim of the present study was to investigate the influence of heavy metals on the polymorph transformation of tricalcium silicate. Heavy metal (0.1wt% to 3.0wt%) of Cr, Zn, Cu, Ni and Pb (in oxides form) was added into the raw mixtures and then sintered together three times at 1450 °C for 2 h. The f-CaO content of doped C₃S was determined by the glycerol-ethanol method, and their polymorph transformation was investigated by means of XRD and FTIR. Thermal analysis (DTA/DTG) was conducted to determine the reaction temperatures and mass losses during the sintering process of raw mixtures. The concentration of heavy metal in C₃S after sintering was determined by ICP-AES. The experimental results indicate that heavy metal doping contributes to a higher symmetry of C₃S except for Pb. Addition of up to 3.0wt%, Cr will lead to a decomposition of C₃S into C₂S and CaO; Zn will cause a transformation from T1 to M2 polymorph, and then to R polymorph; Cu and Ni cause a gradual transformation from T1 to T2 and then to M1 and/or M2 polymorph. During the sintering process, all the Pb releases into atmosphere because of evaporation.

The carburized graded cemented carbide with the addition of some (Ti, Ta) C was analyzed in detail. The micro-structure and element distribution were measured by using optical microscopy and X-ray photoelectron spectrometry along the gradient direction. The experimental results showed that a large amount of solid solution phases were formed and distributed like clusters in the surface layer of cemented carbide. The cobalt migration was not very notable and the Co-rich layer was close to the surface of cemented carbide.

To develop advanced high speed steel with high vanadium content, a kind of vanadium content 9% high speed steel in the form of circular ring was spray formed under certain thermal conditions. The carbides topography of as-cast and as-sprayed 9V steel were observed. The effects of post thermo-mechanical processing (hot isostatic pressing and hot forging) and heat treatment on the microstructure and carbides distribution were investigated. The spray formed 9V steel typically consists of fine, homogeneous and angular-shaped MC carbides with diameters ranging from 1 to 2 μm. Spray formed 9V steel shows an excellent hot workability following increase of forging ratio due to fine homogeneous carbides. After heat treatment, spray formed 9V steel is composed of MC carbides, martensite and retained austenite. The hardness value of heat treated materials is inversely proportional to the volume fraction of residual austenite. Fine dispersed MC carbides have significant influences on the dislocation motion of spray formed 9V steel.

Based on quasicontinuum (QC) multiscale simulation method, a series of simulation models were set up for bending and compressing rod-shaped microstructure of single crystal Cu. The effects of structural parameters on typical mechanical properties were analyzed, such as elastic modulus, elastic limit, yield strength, and Poisson’s ratio. According to the analysis of displacement, inner stress and strain energy, the mechanisms of deformation and failure were also revealed. The experimental result shows that the mechanical properties exhibit obvious size effect during the bending and compression process. In the bending simulation, when the span-thickness ratio is more than 10, the elastic modulus rises slightly with the increase of strain. And the smaller the beam is, the faster the elastic modulus grows. Meanwhile, when the span-thickness ratio keeps constant the elastic modulus will decrease with the growth of the beam sizes. However, in the compression model, the size effect on Poisson’s ratio is not remarkable. The dimensional change in one direction cannot influence the mechanical parameters greatly. Mechanical twins and dislocation contribute to the compression behaviour greatly. Meanwhile, the stress concentration can also be found in the inner partial area and the strain energy decreases abruptly after the crush of beam microstructure.

In order to improve the wear resistance and restrain nickel release of TiNi alloys, the Mo modified layers on TiNi substrates were obtained using the double glow plasma surface alloying technique. Scanning electron microscopy (SEM), glow discharge optical emission spectroscopy (GDOES) and X-ray diffraction (XRD) were employed to investigate the morphology, composition and structure. Microhardness test and scratch test were performed to analyze the microhardness and coating/substrate adhesion. Tribological and electrochemical behaviors of the Mo modified layers on TiNi were tested by the reciprocating wear instrument and electrochemical measurement system. The Ni concentrations in Hanks’ solution where surface electrochemical tests took place were measured by mass spectrometry. The surface-modified layer contained a Mo deposition layer and a Mo diffusion layer. The X-ray diffraction analysis revealed that the modified layers were composed of Mo, MoTi, MoNi, and Ti₂Ni. The microhardnesses of the Mo modified layers treated at 900 °C and 950 °C were 832.8 HV and 762.4 HV, respectively, which was about 3 times the microhardness of the TiNi substrate. Scratch tests indicated that the modified layers possessed good adhesion with the substrate. Compared with as-received TiNi alloy, the modified alloys exhibited significant improvement of wear resistance against Si₃N₄ with low normal loads during the sliding tests. Mass spectrometry displayed that the Mo alloy layers had successfully inhibited the Ni release into the body.

Hardwood residue (HR), a byproduct of paper industry, was liquefied by using polyethylene glycol 400 (PEG400) and ethylene carbonate (EC) as the liquefaction solvents, and concentrated sulfuric acid as the catalyst to produce bio-polyols (HRLP), which were used to synthesize polyurethane (PU) foams. The effects of conditions on the properties of HRLP and modified PU foams were investigated and the mechanism of biomass liquefaction was discussed. The optimum conditions of liquefaction were obtained as follows: reaction temperature of 160 °C, reaction time of 60 min, ratio of PEG400/EC of 8:2 (w/w), and ratio of liquid/solid of 5:1 (w/w). The characterization of HRLP modified PU foams suggested that HRLP could partially replace the petroleum polyols to synthesize PU foams. With the increase of the replacement percentage of HRLP, the apparent density and compressive strength of the foams increased firstly, and then decreased. Meanwhile, the thermal stability was improved slightly.

We prepared graphene(GE) with a mean size of 3087 nm. The transition of graphene oxide (GO) to GE was confirmed by UV-visible spectroscopy, Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The experimental results of optical microscopic observation indicated that the GE ranged from 5 to 20 μg /mL did not affect the cell morphologies of the PC12 cells. The results of cell viability and membrane integrity assay supported that of optical microscopic observation and demonstrated that the GE ranged from 5 to 20 μg/ mL presented no obvious cytotoxicity. However, reactive oxygen species (ROS) assay suggested that an elevation of ROS level could be detected when the GE ranged from 20 to 100 μg/ mL. These results showed that the GE ranged from 5 to 10 μg/ mL presented an excellent in vitro biocompatibility and was one kind of potential biomaterials for neural tissue engineering.

Waste packaging polyethylene (WPE) was used to modify raw asphalt by melt blending the components at 190 °C for 1 h in a simple mixer and subsequently machining them at 120 °C for 1 h in a high-speed shearing machine. The effect of modification on the degree of the penetration, the softening point and the ductility of the asphalt was studied using fluorescent microscopy, infrared spectrometry, component changes and various other techniques. The experimental results showed that no chemical reactions took place in the components themselves (saturate, aromatic, asphaltene and resin) during the modifications. The softening point and penetration of the asphalt were found to be closely related to the resulting contents of the asphaltene, saturate and resin components. In addition, aromatics were identified as having the greatest impact on the ductility of the asphalt.

The main objective was to study the anticorrosion performance of poly(o-toluidine)/nano ZrO₂/epoxy composite coating. Poly(o-toluidine)/nano ZrO₂ composite was prepared by in situ polymerization of o-toluidine monomer in the presence of nano ZrO₂ particles. Fourier transformation infrared spectroscopy (FT-IR), UV-visible spectroscopy (UV-vis), X-ray diffraction (XRD), Scanning electron microscopy (SEM), and Thermogravimetric analysis (TGA) were used to characterize the composition and structure of the composite. Poly(o-toluidine)/nano ZrO₂ composite was mixed with epoxy resin through a solution blending method and the three components poly(o-toluidine)/nano ZrO₂/epoxy composite coating was coated onto the surface of steel sample by the brush coating method. The anticorrosion performance of poly(o-toluidine)/nano ZrO₂/epoxy composite coating on steel sample was studied by polarization curve and electrochemical impendence spectroscopy in 3.5% NaCl solution as corrosion environment and also compared with that of poly(o-toluidine)/epoxy composite coating and pure epoxy coating. It was observed that the composite coating containing poly(o-toluidine)/nano ZrO₂ composite has got higher corrosion protection ability than that of poly(o-toluidine). The electrochemical measurement results demonstrated that poly(o-toluidine) fillers improve the electrochemical anticorrosion performance of epoxy coating and the addition of nano ZrO₂ particles increases the tortuosity of the diffusion pathway of corrosive substances.