TiC/TiAl composites with different TiC content were fabricated by rapid heating technique of spark plasma sintering (SPS). The effect of TiC particles on microstructure and mechanical properties of TiAl matrix was investigated. The results indicate that grain sizes of TiAl matrix decrease and mechanical properties are improved because of the addition of TiC particles. The composites display a 26.8% increase in bending strength when 10wt% TiC is added and 43.8% improvement in fracture toughness when 5wt% TiC is added compared to values of TiC-free materials. Grain-refinement and dispersion-strengthening were the main strengthening mechanism. The improvement of fracture toughness was due to the deflexion of TiC particles to the crack.

Density function theory and discrete variation method (DFT-DVM) were used to study the adsorption of [Au(AsS₃)]²⁻ on the surface of kaolinite. The correlation among structure, chemical bond and stability was discussed. Several models were selected with [Au(AsS₃)]²⁻ in different directions and sites. The results show that the models with gold on the edge of kaolinite basal layer contain pincerlike bond among gold and several oxygen atoms and form strong Au−O covalent bond, so these models are more stable than those with gold above or under the layer. The models with gold near to [AlO₂(OH)₄] octahedra are more stable than those with gold near to the vacancy without aluminium. These two stable tendencies in kaolinite-[Au(AsS₃)]²⁻ are stronger than that in kaolinite-Au systems. The interaction between [Au(AsS₃)]²⁻ and kaolinite is stronger than that between gold and kaolinite, and this interaction is strong enough to form the surface complexes.

BaTiO₃/PVDF nanocomposites were prepared via in-situ growth of nanosized BaTiO₃ particles in PVDF matrix by using the sol-gel method. The present elements of BaTiO₃/PVDF nanocomposites were analyzed by an electron probe X-ray microanalyser. Nanosized BaTiO₃ grown in the composite films was characterized by an X-ray diffractometer and a transmission electron microscope, and the dielectric properties of the composite films were measured. The distribution of BaTiO₃ nanoparticles in-situ grown in the PVDF matrix was examined using a scanning electron microscope.

To study the osteogenic ability of tissue-engineered bone constructed by compounding zinc-sintered bovine cancellous bone with rabbit marrow stromal cells (MSCs) in vivo, the zinc-sintered bovine cancellous bone of beta-tricalcium phosphate (TCP) type was prepared by sintering the fresh calf cancellous bone twice and then loading it with zinc-ion. The rabbit MSCs were cultured, induced and seeded onto the zinc-sintered bovine cancellous bones. The tissue-engineered bones were then implanted into the rabbits' back muscles. The newly formed bone tissues were observed by histological methods and the areas of new osseous tissues were measured at the end of the 4th and 8th week. The zinc-sintered bovine cancellous bones alone were implanted on the other side as control. The osteogenic activity of MSCs was identified by alkaline phosphatase (ALP) staining and calcification nod chinalizarin staining. At the end of 4th week, a small amount of new bone tissues was observed. At the end of 8th week, there were many newly formed bone mature tissues. Moreover, the area of the latter was significantly larger than that of the former (P<0.01), while in the control group there was no new bone formation. The tissue-engineered bone, which was constructed by combining zinc-sintered bovine cancellous bone with MSCs, has satisfactory osteogenic capabilities in vivo.

TiO₂ nanometer thin films with photocatalytic antibacterial activity were prepared by the sol-gel method on fused quartz and soda lime glass precoated with a SiO₂ layer. The thin films were characterized by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The results show that sodium and calcium diffusion into nascent TiO₂ film is effectively retarded by the SiO₂ layer precoated on the soda lime glass. The antibacterial activity of the films was determined. The crystalline of TiO₂ nanometer thin film has important effects on the antibacterial activity of the film.

Modified sensing membranes based on fluorecence quenching were prepared by the sol-gel method, using formamide as the drying control chemical additive, tetraethoxysilane as the main material, Ru (phen)₃ Cl₂ as the indicator. The membrane with the optimum thickness of 20–50μm is uniform and crack-free, in which the indicator has a very small leaking rate. The membrane is immersed in water for 50h, the membrane sensing parameter M decreases by less than 5%. The fiber optic oxygen sensor with the sensing membrane has a detection limit of 5×10⁻⁶ M (ppm), a response time of less than 30s, excellent reproducibility and stability.

(Ni_0.81 Fe_0.19)_0.66 Cr_0.34 has a high resistivity and a crystal structure close to that of Ni_0.81 Fe_0.19. The electrical and X-ray diffraction measurements prove that a thin NiFeCr seed layer induces a well (111)-orented Ni_0.81 Fe_0.19 film. Post-annealing treatment improves the magnetic properties of (Ni_0.81Fe_0.19)_0.66 Cr_0.34(45Å)/Ni_0.81Fe_0.19 (150Å)/Ta(55Å) thin film prepared under a deposition field, whereas the inter-diffusion of NiFe/Ta deteriorates the magnetoresistance properties of the film.

Polyacrylate-based conductive coatings were prepared from polyacrylate emulsion as matrix and carbon black (CB) whose surface was treated with titanate coupling agent as conducting particles. One kind of organic crystal was added to study its effects on the electrical conductivity and PTC (positive temperature coefficient) effect of the conductive coatings. Experimental results show that the coatings containing only polyacrylate emulsion and CB exhibit an excellent electrical conductivity but bad PTC effect, and when organic crystal is added, PTC effect is characterized and can increase by 2 orders of magtitude. The critical transformation temperature of polyacrylate emulsion/CB PTC composites is decided by melting point of organic crystals.

The microemulsion copolymerizations of acrylic acid (AA), acrylamide (AM), N-methylol acrylamide (NMA), methylmethacrylate (MMA), butyl acrylate (BA) and acrylonitrile (AN) initiated by the redox initiator ammonium persulfate (APS) and N, N, N′, N′-tetramethylethylenediamine (TMEDA) at ambient temperature were investigated. With this process high solids-content (44.0 wt%) and small (less than 50 nm) particle diameter copolymer latexes were attained. The effects of surfactants, the mechanical stabilities and application properties as an environmentally friendly self-crosslinking pigment printing binder with multifunctional groups were studied.

High performance liquid chromatography with a C18 reverse-phase column was used to separate the five components in cough syrup, including acetaminophen, p-aminophenol, caffeine, chlorphenamine maleate and guaifenesin. The mobile phase consists of 15wt% acetonitrile, 0.004mol/L sodium heptyl sulfonate, 0.03 mole/L potassium di-hydrogen phosphate and triethylamine (volume ratio 13:40:44:3), the pH of which is adjusted to 3.0 by phosphoric acid. The contents of the five components are analyzed on an ultraviolet spectrophotometer at 254nm, with a flow rate of 0.4 mL/min. The results show that the calibration curves are linear in a certain range. The average recovery of five components is between 96.31% and 102.3%.

Defects of polymer-derived Si−C−O fibers were intensively studied by the SEM and TEM techniques and their originations were also discussed on the basis of factors experiments. The defects were found mainly in the form of strumaes, pits and splits on surfaces as well as microflaw networks, porosity clusters and inclusions in the bulk. Factors experiments reveal that a nonuniform or an insufficient curing would result in larger-sized strumaes or interior microflaws. Gas evolution rates due to different firing rates have a great influence on the formation of internal microflaws or porosity clusters and some oxidation-induced pits or splits may be formed on surfaces because of a trace of oxygen or water vapor accumulated from the flowing inert atmosphere during pyrolysis.

A novel topological index W_F is defined by the matrices X, W and L as W_F=XWL. The topological index WF based on the distance-related matrix of molecular graphs is used to code the structural environment of each atom-type in a molecular graph. Good QSPR models have been obtained for standard formation enthalpy of methyl holides. The result indicates that the idea of using multiple matrices to define the distance-related matrix topological index is valid.

Grafting reaction of methyltriethoxysilane on sepiolite surface was studied. The structure of the salinized product before and after thermal treatment was characterized by XRD, TG-DTA, SEM and IR. It is found that the silicon monomers are grafted on the external surface of sepiolite via silicon hydroxyls. The thermal stability remains unchanged after silanization.

To explain the growth mechanism of Al₂O₃/Al Lanxide composites, the dynamics of the directed oxidation of Al−Mg−Si alloys are analyzed. The experimental methods to produce Lanxide composites by directed oxidation of metal melts at high temperatures are presented. The effect of the processing factors on the microstructures and properties of Al₂O₃/Al composites and enforced Al₂O₃/Al composites is also analyzed. Compared with sintering ceramic composites, the advantages of Lanxide process and Lanxide materials are as following: it is a near net shaped process; the process is very simple; the microstructures and properties of Lanxide materials can be adjusted; and this process can be used to infiltrate ceramic fiber or particle preforms.

Al−Cr-pillared montmorillonite was synthesized by using bentonite and Al−Cr pillaring solutions as starting materials. The basal spacing and specific surface areas of the materials were significantly increased relative to those of untreated clays. When the Al/Cr molar ratio (R) was 0.10, the d(001) value and specific surface area of pillared montmorillonite were 1.9194 nm and 165.7 m²g⁻¹, respectively. Thermal stability of the materials was determined using calcined tests and X-ray diffraction (XRD) analysis. The materials formed at different R(0.05;0.10;0.15;0.25) exhibit a high thermal stability at 300°C, especially at initial R=0.10, the basal interlayer spacing of materials is stabilized at 1.7313 nm after calcined at 500°C for 2 h. Adsorption behavior of the materials was studied by adsorption experiments. The results show that the Al−Cr-pillared montmorillonites exhibit much stronger adsorption capacity on Cr⁶⁺ in aqueous solution than untreated clays do.

Effect of SiO₂ content and sintering process on the composition and properties of Pure Carbon Reaction Bonded Silicon Carbide (PCRBSC) ceramics prepared with C−SiO₂ green body by infiltrating silicon was presented. The infiltrating mechanism of C−SiO₂ preform was also explored. The experimental results indicate that the shaping pressure increases with the addition of SiO₂ to the preform, and the pore size of the body turned finer and distributed in a narrower range, which is beneficial to decreasing the residual silicon content in the sintered materials and to avoiding shock off, thus increasing the conversion rate of SiC. SiO₂ was deoxidized by carbon at a high temperature and the gaseous SiO and CO produced are the main reason to the crack of the body at an elevated temperature. If the green body is deposited at 1800°C in vacuum before infiltration crack will not be produced in the preform and fully dense RBSC can be obtained. The ultimate material has the following properties: a density of 3.05–3.12 g/cm³, a strength of 580±32MPa and a hardness of (HRA)91–92.3.

A new kind of functionally graded materials (FGM) with density gradient has come to show great potentials as flier-plates for creating quasi-isotropic compression waves. In order to meet the demand of lower density in the front face for such flier-plate, Mg with a low density of 1.74 g/cm³ is selected to make a Mg−Ti FGM. Mg−Ti alloys with various weight ratios were sintered by spark plasma sintering (SPS) technique at relative low temperatures, and the processing of densification is mainly investigated. It is found that, up to 75wt% Ti, the Mg−Ti alloys can be fully densified at 560°C due to the conglutination of Mg and the formation of a small amount of Mg−Ti solid solution. Finally, the Mg−Ti FGM with a density gradient from 1.74 g/cm³ to 3.23 g/cm³ is successfully fabricated.

Friction stir welding (FSW), a new solid-state welding technology invited in the early 1990s, enables us weld aluminum alloys and titanium alloys etc. The processing of FSW, the microstructure in FSW alloys and the factors influencing weld quality are introduced. The complex factors affecting the properties are researched.

By using high pure Magnesium (99.9 wt%) as matrix and multi-walled bended carbon nanotubes (CNTs) as reinforced phase, carbon nanotubes/magnesium matrix composite was prepared by the foundry method under the argon gas protection, and its mechanical properties were tested. The interface structure and component of plating and un-plating carbon nanotubes were analyzed by TEM and EDS, and the action mechanism was discussed. The experiment results show that the CNTs can strengthen mechanical properties of the nanotube-reinforced Mg matrix composite, the tensile strength and elongation ratio are greatly improved. Furthermore, the plating CNTs are better than un-plating CNTs in strengthening effects. The tensile strength is inereased by 150% and the elongation ratio is increased by 30% than that of matrix when content of CNTs is 0.67 wt%.

Ultrafine Ti(C,N)-based cermet was sintered by SPS from 1050°C to 1450°C and its sintering properties, such as porosity, mechanical properties and phase transformation, were investigated by optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and differential scanning calorimeter (DSC). It is found that the spark plasma sintering properties of Ti(C,N)-based cermet differ from those of conventional vacuum sintering. The liquid phase appearance is at least lower by 150°C than that in vacuum sintering. The porosity decreases sharply below 1 200°C and reaches minimum at 1 200°C, and afterwards it almost keeps invariable and no longer increases. SPS remarkably accelerates the phase transformation of Ti(C,N)-based cermet and it has a powerful ability to remove oxides in Ti(C,N)-based cermets. Above 1 350°C, denitrification occurred. Fresh graphite phase formed above 1 430°C. Both the porosity and graphite are responsible for the poor TRS.

High refractive index TiO₂ thin films were deposited on BK7 glass by reactive electron—beam (REB) evaporation at pressure of 2×10⁻² Pa, deposition rate of 0.2 nm/s and at various substrate temperatures from 120°C to 300°C. The refractive index and the thickness of the films were measured by visible spectroscopic ellipsometry (SE) and determined from transmission spectra. Optical properties and structure features were characterized by UV-VIS, SEM and XRD, respectively. The measurement and analysis on transmission spectra of all samples show that with the substrate temperature increasing from 120°C to 300°C, the refractive indices of thin films increase from 1.7 to 2.1 and the films after heat treatment have higher refractive indices due to its crystallizing. The XRD analysis results indicate that the structure of TiO₂ thin films deposited on BK7 glass at substrate temperatures of 120°C, 200°C and 300°C is amorphous, after post-annealing under air condition at 400°C for 1 hour, the amorphous structure is crystallized, the crystal phase is of 100% anatase with strong preferred orientation (004) and the grain size of crystalline is within 3.6–8.1 nm, which is consistent with results from SEM observation.

The effect of the deferent rubber content substituted for fine aggregate on the mortar performance was studied. The effects of the rubber coated with the coating materials on the mortar compressive strength, bending strength and impact work were discussed. The optimum rubber powder content and the suitable coating material were found. Through the electrical probe test-BEI, SEI and calcium ion distribution, and the slight crack and the interface between the rubber and cement matrix are analyzed. The results show that the rubber powder coated with the surface treatment materials A, B and C has the capability of absorbing a large amount of energy under the compressive and flexural load and the slight cracks of R-C were controlled and restrained.

Activation of the slag cement was performed using a composite activator. Experimental results show that the performance of the cement is remarkably improved. The fineness and specific surface area of the cement are increased by 23.7% and 1.4%, and 3 d flexural strength and compressive strength are enhanced by 20.9% and 22.9%, respectively. Microstructure and phase composition of the hydrates were analysed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results indicate that Ca(OH)₂ in the hydrates decrease obviously. The morphology of the other hydrates appears to be flocculent, with a dense structure. The improvements of the properties is related to the microstructural changes.

The hydration and pore structure of sulphoaluminate MDF cement were studied by X-ray diffractometer (XRD), scanning electron microscope (SEM) and mercury intrusion porosimeter (MIP) etc. The experimental results indicate that hydration products of the materials are entringites (AFt), aluminium hydroxide and CSH (I) gel etc. Due to its very low water-cement ratio, hydration function is only confined to the surfaces of cement grains, and there is a lot of sulphoaluminate cement in the hardenite which is unhydrated yet. Hydration reaction was rapidly carried under the condition of the heat-pressing. Therefore cement hydrates AFt, CSH (I) and aluminium hydroxide gel fill in pores. The expansibility of AFt makes the porosity of MDF cement lower (less than 1 percent) and the size of pore smaller (80 percent pore was less than 250Å), and enhances its strength.

The space effects of oval-shaped furrow pit slopes were analyzed by the elastic mechanics principle. The interaction of limit equilibrium slope angle, friction coefficient, cohesion and horizontal radius of ovalshaped furrow pits has been derived. The oval trumpet-like rock mass is homogeneous and elastic while only loaded by its dead weight. The interaction indicates that the deeper an oval-shaped furrow pit is excavated, the greater the limit equilibrium slope angle. Both the theory base for reducing stripping waste rock in an oval-shaped furrow pit and the basic way to determine the configuration of a stable slope were developed from the mentioned interaction. The theory includes the preceding principles of stability analysis of slopes. Compared with the configuration determined by traditional theory of slope stability, a great quantity of stripping waste rock can be reduced by that determined in this paper under stable conditions.

The genetic algorithm was used in optimal design of deep jet method pile. The cost of deep jet method pile in one unit area of foundation was taken as the objective function. All the restrains were listed following the corresponding specification. Suggestions were proposed and the modified. The real-coded Genetic Algorithm was given to deal with the problems of excessive computational cost and premature convergence. Software system of optimal design of deep jet method pile was developed.

The factors influencing mechanical performances of viscoelastic material are studied. The proper finite element model for dynamical calculating the passive control of wind-earthquake resistance is constructed. A combined element stiffness matrix of damper-brace system is deduced. At last, the theoretical deduction is verified by comparing the theoretical results with experimental ones.

The key technology and the main mechanism of microcrystallizing leucite to reinforce dental glass ceramics were investigated. The feedstock powders were selected, mixed according to the ratios of the theoretical composition of leucite, ball—milled, melted at 1600°C and then cooled to room temperature quickly. The cooled clinkers were ball—milled again to 4 μm. After cold—isostatic pressure molded and air sintered at 1500°C for 1 h, the dental glass ceramics were fabricated. They have following characteristics: excellent mechanical properties (mean compressive strength is 206. 6 MPa), low sintering temperature and good reoccurrence to keep steady quality.