A new niobate compound was synthesized for the first time in Na ₂ O-BaO-Li ₂ O-ZnO-Nb ₂ O ₅ system by solid state reaction. The new compound was studied by X-ray diffraction, electron probe, X-ray microanalysis, chemical analysis and SEM. The result of X-ray powder diffraction shows that NaBa ₂ Li _0.6 Nb _4.8 Zn _0.2 O ₁₅ belongs to orthorhombic tungsten bronze structure, with space group Pba2(32)and lattice parameters a = 12.6115(2)Å, b=12.4981(2)Å, C = 3.9479(3)Å.The X-ray powder diffraction lines of the compound were well indexed.

A rapid method for the determination of impurity elements, such as Zn, Ni, Co, Cr, Cu, Cd and Pb in manganese tetroxide was developed, using inductively coupled plasma atomic emission spectrometry (ICP-AES). The critical instrumental parameters such as sample flow rate and radio frequency incident power were thoroughly optimized. The effect of matrix was also examined. The sensitivity was investigated using calibration curves obtained in presence of the matrix. The obtained recoveries for Ni, Co, Cr, Cu, and Cd at the μg g⁻¹ level were satisfactory and practically independent of the matrix used for the calibration standards. The recoveries of Pb and Zn were less sufficient. The method can be applied for routine analysis and quality control purposes at μg· g⁻¹ level of concentration.

Crystal characteristics of tooth enamel and dentin were investigated using XRD, SEM, and EPMA methods. The results show that the mineral phase in enamel is HA and in dentin is HA and minor whitlockites. The dentin HA and the enamel HA have different crystallinity, the crystallinity of enamel HA is much higher than that of dentin HA. The average particle size of the enamel HA and dentin HA are 897 Å and 309 Å, respectively. The HA in enamel is regularly arranged, and in dentin the (irrangement of HA is different from the enamel HA in the same section. Both the enamel and the dentin are mainly consisted of Ca, P, O, and C, and the trace elements Mg, Sr, Al, Na, and K. The dentin contains more trace elements than the enamel. However, the incorporation of trace elements in both dentin and enamel are very limited. Other impurities such as F and Cl are less than their detection limit. The a and c values of enamel HA are 9.433 Å and 6.896 Å, and those of the dentin HA are 9.498 Å and 6.896 Å, respectively. The expansion in a value results from those the larger size of [CO₃]²⁻ group substituing for the smaller [OH]⁻ group in the channel, and replacement of [OH]⁻ by [CO₃]²⁻ dominates the change in cell parameter, taking into account of other trace elements.

The relation among electronic structure., chemical bond and thermoelectric property of Ca₃ C0₄ O₉ was studied using density function and discrete variation method (DFTDVM). The gap between the highest valence band (HVB) and the lowest conduction band (LCB) shows a semiconducting property. Ca₃ Co₄ O₉ consists of CoO₂ and Ca₂ CoO₃ two layers. The HVB and LCB near Fermi level are only mainly from O(2) 2_p and Co (2) 3d in Ca₂CoO₃ layer. Therefore, the semiconducting or thermoelectric property of Ca₃ Co₄ O₉ should be mainly from Ca₂ CoO₃ layer, but it seems to have no direct relation to the CoO₂ layer, which is consistent with that binary oxides hardly have a thermoelectric property, but trinary oxide compounds have quite a good thermoelectric property. The covalent and ionic bonds of Ca₂ CoO₃ layer are both weaker than those of Co0₂ layer. Ca plays the role of connections between CoO₂ and Ca2 CoO₃ layers in Ca₃ CO₄ O₉, decrease the ionic and covalent bond strength, and improve the thermoelectric property.

The microwave magnetic properties of the ball milled FeCo particles were investigated as functions of ball milling time (t) using microwave electromagnetic parameters analysis techniques. The results show that the imaginary part of intrinsic dynamic permeability (μ_i) of the ball-milled particles is much bigger than that of raw powders. μ_i strongly depends on t and exhibits several slightly damped ferromagnetic resonances. These phenomena are in qualitative agreement with the formation of the corresponding microstructure or the Aharoni s model of non-uniform exchange resonance modes. The present microwave permeability behavior indicates that nanocrystalline materials with the same grain size may exhibit different properties that depend upon the microstructure, which provides a possibility for manufacturing high performance microwave absorber.

In view of the higher temperature of largesize Ni/MH battery in electric vehicle, the effect of temperature on electrochemical performances of hydrogen storage alloy Ml(NiCoMnTi)₅ was investigated systematically. The results show that the electrochemical performances of alloy vary drastically with temperature changing. As temperature rises, the hydrogen equilibrium pressure increases, the width of hydrogen desorption plateau decreases and the gradient increases, leading to a decline of capacity. When temperature rises from 20 °C to 80 °C, the discharge capacity of the alloy decreases from 309.11 mA· h· g⁻¹ to 227.64 mA · h · g⁻¹, but the high rate dischargeability is improved markedly. Higher temperatures also bring about a significant decrease in the cycling stability and selfdischarge property. X-ray diffraction analysis indicates that the alloy has a single phase with CaCu₅-type LaNi₅ structure.

The aim of this study is to show how fractal analysis can be effectively used to characterize the texture of porous solids. The materials under study were carbon papers, the backing material of the gas diffusion layer (GDL) in Proton Exchange Membrane Fuel Cell (PEMFC). The fractal dimensions were calculated by analyzing data from mercury porosimetry. The polytotrafluoroethylene (PTFE) treated carbon paper shows a significantly high fractal dimension value than pure sample, and the high fractal dimension signifies that the physical complexity of the pore surface is enhanced. The fractal dimension can be used as a valid parameter to monitor the textural evolution of the samples as the treatment progresses, as this behaves in a similar way to other textural parameters. The use of fractal analysis in conjunction with the results of classical characterization methods leads to a better understanding of textural modifications in the processing of materiah.

Two different PAN precursors with various comonomers were wet-spun. The properties and structural changes of PAN precursors and their evolution during preoxidation and carbonization process were characterized by the use of DSC, FTIR and traditional parameters, e g, tensile strength. It is demonstrated that acrylamide (AAM) is very effective to make the DSC peak be separated compared to methyl acrylate(MA). As a result, carbon fibers developed from AAM-contained precursors have a better tenacity compared to those developed from MA-contained ones.

Multi-walled carbon nanotubes were fabricated by the pyrolysis of acetylene with naturally occurring marine manganese nodules as a novel catalyst at an elevated temperature. The nanotube product was examined by transmission electron microscopy. The method is expected to be the simplest one to synthesize carbon nanotubes due to unnecessary synthesis of catalyst.

This work mainly investigated the influences of some factors, such as, synthesis methods, precursor alternatives, and vacuum heat-treating process, etc, on the fluorescent characteristics of the semiconductor quantum dots synthesized by aqueous phase. The research results indicate that the fluorescent characteristic of water-solution sample prepared from Na₂ S0₃ precursor was sensitive to water bath heating time, and specially, its photoluminescence spectrum shows the unique phenomenon of double excitation and emission peaks. Meanwhile, the fluorescent characteristic of water-solution sample prepared from NaBH₄ precursor is slightly influenced by water bath heating time, and the surface of CdSe quantum dots could be passivated by the excessive amount of NaBH₄ precursor, which results in the effective decrease of surface traps and great enhancement of quantum yield. Furthermore, the fluorescent emission peaks of samples could be sharpened by vacuum heat-treating process, with its spectral full width at half of maximum (FWHM) around 30–40 nm, so the emission peaks become redshifi, of which the intensity greatly increases.

V₂ O₅ nanotube arrays in porous anodic alumina (PAA) template were obtained from V₂ O₅ sols prepared by melt quenching method. X-ray powder diffraction and selected area electron diffraction investigations demonstrate that V₂ O₅ nanotubes are orthorhombic. Results by scanning electron microscopy and transmission electron microscopy results show that V₂ O₅ nanotubes with a uniform diameter form highly ordered arrays. The diameter and length of the nanotubes depend on the pore diameter and the thickness of the PAA template used. It is proved that the sol-gel template process is a cost-saving, simple and readily-controlled method to prepare metal oxides nanomaterials. Owing to the quantum size effect, the optical absorption edge of V₂ O₅ nanotubes in PAA exhibits a significant blue shift with respect to that of bulk V₂ O₅.

92WC-8 Co powder mixture with superfine-tungsten carbide was respectively sintered by spark plasma sintering(SPS) and sintering isostatic pressure (SIP). Complete dense samples with 200 nm WC grains and 94.2 HRA hardness were prepared by spark plasma sintering at 1 150 °C and under 4.5 kN for 5 minutes. SIP was carried out at 1 400 °C for 30 minutes with a result of 300–400 nm WC grains and 93 HRA hardness. The results show that sintering temperature is greatly decreased by SPS, sintering time is largely shortened and WC grain growth is effectively retarded. Micropores and drawbacks in superfine-cemented carbide made by SPS are greatly declined, which is very useful to improving mechanical properties.

The rods that were shaped from nanocrystalline WC-10.21 Co-0.42 VCI Cr₃ C₂(wt%) composite powders by using powder extrusion molding (PEM) were investigated. The nanocrystalline WC-10.21 Co-0.42 VC/Cr₃ C₂ (wt%) composite powders were prepared by the spray thermal decomposition-continuous reduction and carburization technology. In order to improve the properties of rods shaped by using powder extrusion molding, the cold isostatic pressing (CIP) technology was used before or after debinding. Specimens were sintered by vacuum sintering and hot isostatic pressing (HIP). The density, Rockwell A hardness, magnetic coercivity, and magnetic saturation induction of sintered specimen were measured. The microstructure of the green bodies and the sintered specimens was studied by scanning electron microscopy (SEM). Results show that the rod formed by using powder extrusion molding after debinding and followed by cold isostatic pressing can be sintered to 99.5% density of composite cemented carbide rods with an average grain size of about 200–300 nm, magnetic coercivity of 30.4 KA/m, Rockwell A hardness of 92.6 and magnetic saturation induction of 85%. Superfine WC-10Co cemented carbide rods with excellent properties were obtained.

C⁺ ion beam-assisted deposition was utilized to prepare deposit diamond-like carbon (DLC) film. With the help of a series of experiments such as Raman spectroscopy, FT-IR spectroscopy, AFM and nanoindentation, the DLC film has been recognized as hydrogenated DLC film and its tribological properties have been evaluated. The ball-on-disc testing results show that the hardness and the tribological properties of the DLC film produced by C⁺ ion beam-assisted deposition are improved significantly. DLC film produced by C⁺ ion beam-assisted deposition is positive to have a prosperous tribological application in the near future.

La_0.7 Ca_0.3 CrO₃ powder consisting of superfine and uniform particles (100-200 nm) were synthesized using a glycine-nitrate process (GNP). The sintering and electronic conducting properties of La_0.7 Ca_0.3 CrO₃ were investigated in the sintering temperature range of 1 200–1450 °C. The desired morphology of the powder significantly improved its sinterability. La_0.7 Ca_0.3 CrO₃ ceramics sintered at 1 250–1450 °C show high relative densities above 95%. The ceramics sintered at 1 250–1400 °C have very similar electronic conducting properties, providing electronic conductivities around 55 Ω⁻¹ cm⁻¹ at a measuring temperature of 800 °C. Further increasing the sintering temperature to 1450 °C led to an apparent degradation of electronic conducting properties. This research demonstrates the advantage of the GNP in producing La_0.7 Ca_0.3 CrO₃ with respect to the enhanced sintering properties and superior electronic conducting properties.

The catalytic performance of perovskite composite oxide catalyst La_0.9 K_0.1 CoO₃ coated on catalyst supports by traditional solid state reaction method and sol-gel method were investigated by a series of experiments. The result shows that the catalytic performance of the La_0.9 K_0.1 CoO₃ perovskite composite oxide catalyst synthesized by sol-gel method is superior to that synthesized by solid state reaction method, having lower ignition temperature of the diesel soot particulates, lower start temperature of NO_x treatment, and lower concentration of by-product CO.

The ratio of Fe-Al compound at interface, which could determine the quantity of Fe-Al compound at the interface of steel-mushy Al-20Sn bonding plate, was used to characterize the interfacial structure of steel-mushy Al-20Sn bonding plate quantitatively. The effect of ratio of Fe-Al compound at interface on interfacial shear strength was investigated perfectly. The results show that the relationship between ratio of Fe-Al compound at interface and interfacial shear strength is S =3.3+1.91t -0.0135 t² (where t is ratio of Fe-Al compound at interface and S is interfacial shear strength). When the ratio of Fe-Al compound at interface is 71%, the largest interfacial shear strength 70.9 MPa is got. This reasonable ratio of Fe-Al compound at interface is a quantitative criterion of interfacial embrittlement. When the ratio of Fe-Al compound at interface is higher than 71%, interfacial embrittlement will occur.

The microstructure and mechanical properties of a new-type of cermets cutter (tool A) with nano-TiN modification and its cutting properties in cutting gray cast iron are investigated. SEM and TEM observations of the microstructure of the above material reveal that nano-TiN modified cermets possess a finer microstructure than conventional cermets. In the cutting tests, for comparison, cemented carbide cutter (YG8, tool B) was also utilized. The cutting results show that the cutting properties of tool A are superior to those of tool B. It is also found that the predominant failure mode of tool A is normal wear and micro-spoiling under lower cutting quantities, and that chipping occurs under higher cutting quantities. SEM analysis reveals that cohesion, oxidation and diffusion wear become very apparent at a higher cutting speed. On the contrary, grain wear also exists but is not apparent.

The nanostructures of the ball milled FeCo particles were characterized as functions of the ball milling time (t) using quantitative X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM) analysis techniques. The results show that the nanocrystalline bcc FeCo particles are available using carbonyl iron and cobalt powders as the start materials during the high-energy ball milling. At the early stage of ball milling, Co powders are easily mashed into nanocrystalllites, by which the surface of the larger Fe particles of about 80–150 nm is coated. With t increasing, the refinement of grain size and the incorporation of defects including dislocations, disclinations and grain boundaries happen, and then FeCo alloy with a certain layered structure is formed, finally the layered structure disappears with the formation of isotropic grains having a steadystate grain size in the nanometer regime after a certain period of t.

SiCp/Al composites containing high volume fraction of SiC particles were fabricated by spark plasma sintering (SPS), and their thermophysical properties, such as thermal conductivity (TC) and coefficient of thermal expansion (CTE), were characterized. The electric field in the vacuum column was calculated and the generation condition of the spark was analyzed. Spark can be generated by a low current if the cavity in the green body is large enough. A high relative density of the composites was successfully achieved through the optimization of sintering parameters. The measured TCs of the SiCp/Al composites fabricated by SPS are higher than 195 W/ m · K.

Continuous extruding/ extending forming process for A20/7 alloy in semisolid state was proposed through installing extending die at the outlet of shearing-cooling-rolling (SCR) machine. A series of experiments to produce flat bar of A 2017 alloy were carried out. The forming process, metal flow behavior in die and microstructure and mechanical property of products were investigated. It is shown that if the pouring temperature of melt was higher, the die was filled with semi-solid slurry with low solid fraction and periodical cracks would occur on the product surface; If its pouring temperature was lower or the preheating temperature of die was lower, semisolid slurry would solidify rapidly and block the die after entering the cavity. The analysis of mass flow trace shows that the semi-solid slurry moves forward layer by layer and fills the die extending caviiy in radiation manner and the velocity of mass flow in the central area of extending cavity and exit of mould is the maximum, and then decreases gradually from the center to both sides of die wall. By increasing the die extending angle, the velocity of mass flow becomes more homogeneous. Under rational process control and die design, the A2017 flat bar with transverse section of 10 × 50 mm and with good surface and fine equiaxed grains can be obtained by continuous extruding/ extending forming process. The product’s tensile strength and elongation are 420.5 MPa and 14.2%, respectively.

The effect of rectangle wave pulse current on solidification structure of ZA27 alloy was studied. The results show that the wave pattern relies on the frequency range of harmonic wave and the energy of pulse current within the frequency range of pulse current. Imposed pulse current could induce the solidification system to oscillate. The frequency range and the relevant energy distribution of pulse current exert an influence on the amount of atoms involved for forming critical nucleus, the surface states of clusters in melt, the oscillating state of melt on the surface of clusters, the active energy of atom diffusion, the frequnce response of the resonance of bulk melt and the absorbability of the solidification system to the external work. Rectangle wave pulse current involves rich harmonic waves; the amplitudes of high order of harmonic waves are higher and reduce slowly, so it has a better effect on inoculation and modification.

Lead zirconate titanate (PZT)/polyvinylidene fluoride (PVDF) 0-3 piezoelectric composites doped with polyaniline (PANI) were obtained by hot-press method. The polarization properties of the composites were characterized by XRD and P-E hysteresis loops at room temperature. And the dielectric and piezoelectric properties were also measured. The results show that the poling of PZT could be effectively carried out and the dielectric constant ε_r, and dissipation tanδ increase monotonously by increasing the volume fraction of PANI in the composite. The piezoelectric constant d₃₃, and the planar electromechanical coupling factor k_p increase while the mechanical quality factor Q_m decreases with the increase in the content of PANI. The d₃₃, k_p and Q_m show the extremum values at 8 vol%-10 vol% PANI.

CdS thin films were deposited by ILGAR(ion lay gas reaction) method. The effect of annealing temperature under N₂ atmosphere on the structural, chemical, topographical development and optical and electrical properties of CdS thin films was investigated by XRD, SEM, XPS, UV-VIS and two-probe technique. It is found that the cubicphase of as-deposited CdS film transforms to hexagonal phase with a perfected orientation along (002) plane at 300 °C. The band gap decreases with increasing annealing temperature until 300 °C, which is consistent with the grain growth. The fall of dark and light resistivitiy is obvious with increasing annealing temperature, corresponding to the continuous grain growth and deviation of stoichiometry at higher temperature. The smooth and uniform surface of as-deposited films becomes rougher through thermal treatment, which is related to grain growth and sublimation of CdS at a higher annealing temperature.

The bentonite was modified using Cabentonite as a matrix and octadecyl/hexadecyl ammonium chloride as the cover agent, based on hydrothermal process. The organic gel with 5.0 Pa · s viscosity was synthesized by dispersing it into the dimethyl benzene-methyl alcohol system fully. The optimum process conditions for organic modification were that the coating agent dosage is 22 g/L, reaction time is 90 minutes and the pH value of pulp is 10. X-ray diffraction (XRD) analysis indicates that the d (001) value of the modified bentonite is 20. 532 Å. The influence of gel temperature on its viscosity characteristic was studied. By analyzing the transmssion electron microscopy (TEM) images and observing the dispersed gel, the nanometer effect of the organic gel was discussed.

A super absorbent material was prepared with the super absorbent resin (SAR) and inorganic gel. The SAR of the carboxymethyl cellulose grafting acrylic acid (CMC-AA) was copolymer synthesized using the method of inversephase suspension polymerization. The influences of the monomer concentration, neutralization degree, the initiator, dispersion agent, cross-linking agent, reaction and drying temperature on the grafting copolymer properties were examined. Meanwhlie, its properties was investigated and the model for absorption mechanism of this absorbent composite was proposed.

New liquid free radical-cationic hybrid photopolymer, consisting of acrylate-based photocurable resin and epoxy-based photosensitive resin for stereolithography by UV laser was developed. The experiment results indicated that the hybrid photopolymer exhibits advantages of both the acrylate-based photosensitive resin and the epoxy-based photosensitive polymer contained in the hybrid system with relatively high photospeed and low linear shrinkage. Stereolithography parts without obvious distortion were built on the stereolithography apparatus HRPLA-I from this hybrid resin successfully and efficiently.

Alumina sols with a molar ratio of 1:50 between aluminum sec-butoxide (ASB) and H₂O were fabricated by adding various amounts of nitric acid. The particle shape, zeta potential, polydispersity and effective particle size of alumina sol were examined by a TEM, a zeta PALS granularity analyzer and a zetaPALS zeta potential analyzer, respectively. By analyzing the change of zeta potential and double-layer thickness with nitric acid concentration, the potential energy curves of colloidal particles were mapped on the basis of DLVO theory, and the effects of nitric acid concentration on the stability of alumina sols were intensively studied. The results show that for the alumina sols with a mol ratio of 1:50 between ASB and H₂O, the total interaction energy of the colloidal particle is at a maximum when the nitric acid concentration is 0.22 mol/L. Therefore, the stability of the colloid reaches optimum at the nitric acid concentration of 0.22 mol/L.

The homogeneous GeS₂-In₂ S₃-Csl glassy samples were prepared by conventional meltquenching method. When the molar ratio of In₂ S₃, to Csl remains 1, the mm-crystalline region can extend to the composition 0.4 GeS₂ -0.3In₂S₃ 0.3 Csl. And with the addition of Csl, the glassforming ability of this serial glass reaches its maximum at the composition 0.8 GeS₂ −0.1 In₂ S₃ −0.1 Csl. According to the Raman spectra, the microstructure of these glasses is mainly constituted by [GeSt] and [lnS_4−xIx] telrahedra, which are interconnected by the bridging sulfur atoms; meanwhile, the ethaneliked structural units [S₃ Ge−GeS₃] can be formed because of the lacking of sulfur;Cs⁺ ion, which is added from Csl, exists as the nearest neighbor of I-ion in the glassy network.

Zinc aluminosilicate glosses containing Li2 O, ZnO, Al₂O₃ and SiO₂ were prepared by conventional melting and quenching technique, and subsequently converted to transparent glass-ceramics by controlled nucleation and crystallization. The glass was melted in a platinum crucible at 1 600 °C for 2 h and then two-step heat treated for the nucleation and the crystal growth. The nucleation and crystallization temperatures were determined by differential thermal analysis. Specimens heat-treated on different schedules were analyzed by the X-ray diffraction to determine crystalline phases. Scanning electron microscopy was used to study the glass-ceramics morphology, the grain size and distribution in the residual glass matrix. The reorganization of the amorphous solid was confirmed by FT-IR spectroscopy. The transmittance was measured by a UV-Vis-NIR scanning spectrophotometer.

The objective of this study is to investigate the local stress fluctuation in two-phase composite by homogenization method. The composite was described by homogeneous macro structure and periodical micro structure simultaneously and the mechanical response of the composite can be described based on both macro and micro dimensional scales. Micro and macro homogenization problems can be formulated. The effective material properties of the composite and the local stress field in the microstructure of the composite can be determined by solving these equations.

Polyester fibre and floc xylogen fibre were used to prepare fibre-asphalt binder. An SHRP’ s dynamic shear rheometer (DSR) was employed to investigate the rheology characteristics of fibre-asphalt binder, and the flow resistance of binder was revealed by combining the rutting parameter, G * / sinδ. The results indicate that both kinds of fibres remarkably improved the high temperature performance of asphalt binder. At the same time, the reinforcement mechanism of the fibres in the asphalt binder was also analyzed.

The resistance response to temperature change of carbon fiber reinforced cementbased composites (CFRC) is reported, which shows some outstanding phenomena of positive temperature coefficient (PTC) of resistance and negative temperature coefficient (NTC) of resistance during the temperature rising. The influences of carbon fiber, cementbased matrix and thermal cycles on the characteristics of temperatureresistivity for the system were also discussed. Because of the special characteristics for temperatureresistivity, carbon fiber cement based composites can be useful in structure with the function of alarm for fire.

The effect of the ground granulated blast-furnace slag (GGBFS) addition, the modulus n (mole ratio of SiO₂ to Na₂ O) and the concentration of sodium silicate solution on the compressive strength of the material, i e alkali-activated carbonatite cementitious material (AACCM for short) was investigated. In addition, it is found that barium chloride has a satisfactory retarding effect on the setting of AACCM in which more than 20% (by mass) ground carbonatite was replaced by GGBFS. As a result, a cementitious material, in which ground carbonatite rock served as dominative starting material, with 3-day and 28-day compressive strength greater than 30 MPa and 60 MPa and with continuous strength gain beyond 90 days was obtained.

The mix designs and specimen preparation for the dry process and wet process of sulfur rubber concrete (SRC) were investigated. The compressive strength, corrosion-resistance and toughness were studied and discussed. The results show that SRC is corrosionresistanct. Although the compressive strength of SRC decreases with increasing rubber content, the toughness increases instead. Adding micro-filler will improve the compressive strength of SRC. There is a threshold value for the sulfur content, at which the compressive strength and the workability of SRC reach an optimum balance. The bond between rubber particles and surrounding sulfur is strong due to the vulcanization process that generates cross-links through S-C bonds.

This research indicates that the gradient of internal relative humidity (IRH) decreases rapidly within 1-day curing age in HPC. The amount of water imported by pre-wetted light-weight aggregate can regulate IRH of concrete. By importing a proper amount of water, the process of the decline of IRH can be delayed and the autogenous shrinkage can be reduced. The relationship among the amount of water imported by pre-wetted lightweight aggregate, IRH and AS was established. The result provides a new method of reducing early AS and enhancing early cracking resistance of HPC.

The effects of Ethylene-Vinyl Acetate copolymer (EVA) latex as an additive or a glass fiber surface modifier on the properties of Glass-Fiber (GF)/Magnesium Oxychloride Cement (MOC) composites was studied. The mechanical properties, water resistance and aging resistance of the cured GF/MOC composites were estimated and chemical ingredients analysis and morphological study of the GF/MOC composites were also performed. It is found that EVA added to the MOC matrix could substantially improve the interfacial adhesion, water resistance and aging resistance of GF/MOC composites. EVA treatment on glass fibers resulted in decreasing initial flexural strength of GF/MOC composites while enhancing the soft coefficients. In addition, the drying time and dilution of the EVA treatment on glass fibers also had an obvious effect on the properties of GF/ MOC composites. However, excessive EVA interfered with the growth of the 5Mg(OH)₂ · MgCl₂ · 8H₂O crystal and the properties of GF/MOC composites.

A research project was conducted to manufacture eco-cement for sustainable development using cement kiln dust (CKD) and granular blast furnace slag(GBFS). In the project, the burning process and mineral compositions of CKD clinker were investigated. Different mineralizers such as CaSO₄ and CaF₂ sulfur and alkali content were considered. The strength of CKD and GBFS eco-cement were evaluated. The results indicate the CKD clinker can not only form ordinary cement clinker minerals such as C₃S, C₂S and C₄AF, but also form such high-reactive minerals as C₄ A₃ S and C₁₁ A₇, · CaF₂. The CKD and GBFS eco-cement will have the similar strength to the Portland cement grade 32.5 when blend proportion is properly applied.

Hydration heat evolution, non-evaporative water, setting time and SEM tests were performed to investigate the effect of fine steel slag powder on the hydration process of Portland cement and its mechanism. The results show that the effect of fine steel slag powder on the hydration process of Portland cement is closely related to its chemical composition, mineral phases, fineness, etc. Fine steel slag powder retards the hydration of portland cement at early age. The major reason for this phenomenon is the relative high content of MgO, MnO₂, P₂ O₅ in steel slag, and MgO solid solved in C₃ S contained in steel slag.

Using the laser granularity survey technology, X-ray powder diffraction, scanning electron microscopy (SEM) and infrared spectrum analysis methods, we studied the microscopic structure and chemical bonds changes of β-C₂ S monomineral under the high energy ball grinding function. The result indicates that, continuously under the mechanical power, β-C₂ S crystal size would decrease, the micro strain and the effective Beff parameter would increase, and the amorphous phases would be presented. Furthermore, the mechanical power would cause Si-O bond broken and reorganized, the specific surface area would increase, the energy of micro-powder agglomeration vibration would be enhanced and the crystal would be disordered. Finally, β-C₂S was caused to have the mechanochemical change and the activity enhancement.