Mo-C codoped TiO₂ films were prepared by RF magnetron cosputtering. Ultraviolet-visible spectroscopy, atomic force microscopy, X-ray photoelectron spectroscopy, energy dispersive X-ray Analysis and X-Ray Diffraction were used to study the influences of codoping on energy gap, surface morphology, valence states of elements, ions content and crystal structure, respectively. The concentration of photogenerated carriers was measured by studying photocurrent density, while catalytic property was evaluated by observing degradation rate of methylene blue under visible light. A Mo-doped TiO₂ film, whose content of Mo had been optimized in advance, was prepared and later used for subsequent comparisons with codoped samples. The result indicates that Mo-C codoping could curtail the energy gap and shift the absorption edge toward visible range. Under the illumination of visible light, codoped TiO₂ films give rise to stronger photocurrent due to smaller band gaps. It is also found that Mo, C codoping results in a porous surface, whose area declines gradually with increasing carbon content. Carbon and Molybdenum doses were delicately optimized. Under the illumination of visible light, sample doped with 9.78at% carbon and 0.36at% Mo presents the strongest photocurrent which is about 8 times larger than undoped TiO₂ films, and about 6 times larger than samples doped with Mo only.

To develop an efficient and bio-compatible way to improve the thermal and mechanical properties of addition type liquid silicone rubber (LSR), a series of modified LSR samples were prepared by introducing octavinyl-polyhedral oligosilsesquioxanes (VPOSS) and high purity silicon sol singly or in combination before vulcanization. Significant correlation was found between the loading rate of VPOSS and thermal properties. However, mechanical properties were negatively correlated with VPOSS content within the range experimented, which may be ascribed to material defect caused by uneven distribution and aggregation. Furthermore, test results approved that the introducing of silicon sol indeed affected the stabilities of the polymer by restraining the material defect caused by the aggregation of POSS molecules and improving cross link density. For example, adding 10%-20% of silicon sol into VPOSS(1.0%) modified LSR will increase tear resistance by 43.9%-85.7%, elongation at break by 31.7%-57.3%, residue at 800 °C in N₂ atmosphere by 32.0%-37.9%, residue at 650 °C in air atmosphere by 70.9%-91.6%, respectively. This work proves that, to incorporate VPOSS into LSR by hydrosilylation, and to use silicon sol as dispersant and reinforce filler can become an efficient way to improve the mechanical property, thermal stability and bio-compatibility of LSR in the future.

To improve the electrochemical performances of α-MnO₂ as electrode materials for supercapacitors, Sn-doped α-MnO₂ in the presence of the doping amount of 1%-4% was successfully synthesized by hydrothermal method. As-prepared α-MnO₂ presents nanorod shape and no other impurities exist. By ultraviolet-visible absorption spectroscopy, it is convinced that the band gaps of α-MnO₂ decrease with increasing Sn-doping amount. Cyclic voltammetry investigation indicates that undoped and doped α-MnO₂ all have regular capacitive response. As the scan rate enlarged, the profiles of curves gradually deviate from rectangle. Compared with undoped α-MnO₂, doped α-MnO₂ has larger specific capacitance. The specific capacitance of 3% doped α-MnO₂ reaches 241.0 F/g while undoped α-MnO₂ only has 173.0 F/g under 50 mA/ g current density in galvanostatical charge-discharge measurement. Enhanced conductivity by Sn-doping is considered to account for doped sample’s enhanced electrochemical specific capacitance.

In order to improve the oxidation resistance of TiAl alloy, silicide coatings were prepared by pack cementation method at 1273, 1323, and 1373K for 1-3 hours. Scanning electron microscopy (SEM), energy dispersive spectrometry (EDS) and X-ray diffraction (XRD) were employed to investigate the microstructures and phase constitutions of the coatings. The experimental results show that all silicon deposition coatings have multi-layer structure. The microstructure and composition of silicide coatings strongly depend on siliconizing temperatures. In order to investigate the rate controlling step of pack siliconizing on TiAl alloy, coating growth kinetics was analyzed by measuring the mass gains per unit area of silicided samples as a function of time and temperature. The results showed that the rate controlling step was gas-phase diffusion step and the growth rate constant (k) ranged from 1.53 mg²/(cm⁴·h²) to 2.3 mg²/(cm⁴·h²). Activation energy (Q) for the process was calculated as 109 kJ/mol, determined by Arrhenius' equation: k = k ₀ exp[–Q/(RT)].

Pure copper plates were coated by Ni-TiC dipulse current plating method. The effects of adding different concentration(ranging from 0.5 g/L to 3.0 g/L) of attapulgite nano particles to the plating bath on the surface morphology, wear resistance, and oxidation resistance of Ni/TiC/Attapulgite nano-composite coatings were investigated. The experimental results show that the composite coating is flat and compact with adding 3.0 g/L in the bath, and the coating preferred orientation is changed from the planes (111) to (200). The coefficient of the composite coatings decreases from 0.68 to 0.18 with increasing content of attapulgite in the bath, a mixed mode of adhesive-abrasive wear occurs for all coatings, and the wear mechanism shows a transition from adhesive-abrasive to predominantly abrasive wear mechanism when the concentration of attapulgite is beyond 1.5 g/L in electrolyte. The oxidation resistance of composite coatings is the best prepared when adding attapulgite particles at 0.5 g/L in the bath, the oxide mainly consists of a NiO phase by X-ray analysis.

Learning from the process of biominerals formation provides tremendous ideas for developing advanced synthesis techniques. According to the structure formation of tooth enamel, a recombinant amelogenin his-AmelX was designed and constructed. The protein was over-expressed and could be conveniently purified in one-step heat treatment. The mineralization process of hydroxyapatite was initiated by enzyme AP and regulated by the recombinant amelogenin. Effects of solution pH value and mineralization duration were studied. It was demonstrated that his-AmelX could induce the nucleation of apatite and quicken the growth rate at pH 7.0-7.4, while impeded hydroxyapatite growth at pH 6.8. Moreover, a much denser layer of hydroxyapatite was achieved with the addition of his-AmelX. The present study may not only provide insight into the formation of natural biomaterials but also open a new path to prepare materials under environmentally benign conditions.

A novel gap-plasmon of Fe₃O₄@Ag core-shell nanoparticles for surface enhanced fluorescence detection of Rhodamine B (RB) was developed. Fe₃O₄@Ag core-shell nanostructures with Ag shell and Fe₃O₄ core were synthetized by self-assembled method with the assistance of 3-mercaptopropyl trimethoxy silane (MPTS). To study the RB fluorescence enhanced by gap-plasmon, the fluorescence properties of RB on the substrates with different nanogap densities were systematically investigated, and the results showed that the fluorescence intensity of RB on Fe₃O₄@Ag core-shell NPs substrate was much stronger than that on bare glass substrate, and the fluorescence intensity was further improved by using multilayer Fe₃O₄@Ag core-shell NPs substrate which had higher nanogap density. Different from the mechanism that is based on the maximum overlap of the surface plasmon resonance (SPR) band and emission band, the mechanism of the fluorescence enhancement in our work is based on the localized surface plasmon (LSP) and the gap plasmon near-field coupling with the Fe₃O₄@Ag core-shell NPs. Besides, the detection limit obtained was as low as 1×10^-7 mol/L, and the Fe₃O₄@Ag core-shell NPs substrate had high selectivity for RB fluorophores. It was demonstrated that the Fe₃O₄@Ag core-shell NPs substrate had activity, good stability, and selectivity for fluorescence detection of RB. And the detection of RB by the surface plasmon enhanced fluorescence was more convenient and rapid than the traditional detection methods in previous works.

The friction reducing properties of sulfonated graphene as a lubricating additive were investigated using a four-ball machine tester with high carbon chromium bearing steels GCr15 (SAE52100) friction pairs. The microscopic morphology, elemental composition, and self-repairing properties were observed and analyzed by using scanning electronic microscopy (SEM), X-ray diffraction (XRD) and digital microscopy. The relationships among sulfonated graphene ethanol solution concentration, friction coefficient, and abrasion loss were revealed. It was found that the optimal concentration of ethanol solution with the addition of sulfonated graphene was 0.15g/mL and the coefficient of friction was only 0.105 under certain condition. Then the stable chemical properties and good anti-corrosion properties of the metal-graphene layer were further confirmed using salt spray corrosion test. In summary, sulfonated graphene can be used as a new kind of self repairing additive, and it has excellent wear-resistant and self-repairing performances.

The longitudinal tensile properties of SiC_f/Ti-6Al-4V composites with different fiber volume fractions were simulated by the Monte Carlo 2-D finite element model. The random distribution of fiber strength was expressed by the two-parameter Weibull function. Meanwhile, contact elements and birth-death elements were used to describe the interfacial sliding process after debonding and fiber breakage (or matrix cracking) respectively, which was realized by subroutine complied in ANSYS-APDL (ANSYS Parametric Design Language). The experimental results show that the yield stress and ultimate tensile strength of SiC_f/Ti-6Al-4V composites increase with increasing fiber volume fraction, while the corresponding strain of them is just on the contrary. In addition, almost the same failure mode is obtained in SiC_f/Ti-6Al-4V composites with various fiber volume fractions when the interfacial shear strength is fixed. Finally, the tensile strength predicted by finite element analysis is compared with that predicted by Global load-sharing model, Local load-sharing model and conventional rule of mixtures, thus drawing the conclusion that Local load-sharing model is very perfect for the prediction of the ultimate tensile strength.

ZrC coatings were deposited on graphite substrates by low pressure chemical vapor deposition (LPCVD) with the Br₂-Zr-C₃H₆-H₂-Ar system. The effects of deposition time on the microstructures and growth behavior of ZrC coatings were investigated. ZrC coating grew in an island-layer mode. The formation of coating was dominated by the nucleation of ZrC in the initial 20 minutes, and the rapid nucleation generated a fine-grained structure of ZrC coating. When the deposition time was over 30 min, the growth of coating was dominated by that of crystals, giving a column-arranged structure. Energy dispersive X-ray spectroscopy showed that the molar ratio of carbon to zirconium was near 1:1 in ZrC coating, and X-ray photoelectron spectroscopy showed that ZrC was the main phase in coatings, accompanied by about 2.5mol% ZrO₂ minor phase.

A new method regarding mesomechanics finite-element research is proposed to predict the peak shear strength of mudded intercalation materials on a mesoscopic scale. Based on geometric and mechanical parameters, along with the strain failure criteria obtained by sample’s deformation characteristics, uniaxial compression tests on the sample were simulated through a finite-element model, which yielded values consistent with the data from the laboratory uniaxial compression tests, implying that the method is reasonable. Based on this model, a shear test was performed to calculate the peak shear strength of the mudded intercalation, consistent with values reported in the literature, thereby providing a new approach for investigating the mechanical properties of mudded intercalation materials.

The objective of the present work was to determine the influence of the neutral salt spray corrosion on the wear resistance of HVOF sprayed NiCr-Cr₃C₂ coating with intermediate layer. Ni-Zn-Al₂O₃ coatings as interlayers were prepared by low pressure cold spray (LPCS) between NiCr-Cr₃C₂ cermet coatings to form a sandwich structure to enhance the corrosion resistance properties. The tribological properties were examined using the UMT-3 fricition and wear tester by line-contact reciprocating sliding under dry and salt spray one week corrosion. The morphology, element distribution, and phase compositions of the coating and worn sufaces were analyzed by using scanning electron microscopy, energy dispersive spectrometry, and X-ray diffraction respectively. The corrosion behavior of the coating was studied by the open-circuit potential, the electrochemical impedance spectroscopy, potentiodynamic polarization, and salt spray corrosion methods. It is found that the sandwich structured coating has better corrosion resistance than the single layer coating. The results show that under dry wear conditions, the wear mechanism is abrasive and adhesive wear, whereas under salt spray corrosion conditions it becomes corrosion wear. The friction coefficient of the sandwich structured coating after salt spray corrosion is slightly lower than the dry friction coefficient, but the weight of the wear loss is lower than that under dry condition.

The effect of Mo on the morphology, crystal structure and hydrogen sorption properties of Mg/C composites prepared by reactive milling was studied. Transmission electron microscopic (TEM) observation shows that Mg/C composites prepared with the addition of Mo are of nanoscale with particle size about 20-120 nm after 3 h of milling under 1 MPa H₂. MgH₂ of tetrahedral crystal structure predominates in the materials with the geometric shape of oblique hexagonal prism. From X-ray diffraction (XRD) and hydrogen content studies, Mo and crystallitic carbon have a synergistic effect on promoting the hydrogenation rate in the reactive milling process. From differential scanning calorimetric (DSC) studies, the dehydrogenation peak temperature of the Mg/C materials with Mo is lowered to 299-340 °C.

This study presents the use of chicken eggshells waste utilizing palm kernel shell based activated carbon (PKSAC) through the modification of their surface to enhance the adsorption capacity of H₂S. Response surface methodology technique was used to optimize the process conditions and they were found to be: 500 mg/L for H₂S initial concentration, 540 min for contact time and 1 g for adsorbent mass. The impacts of three arrangement factors (calcination temperature of impregnated activated carbon (IAC), the calcium solution concentration and contact time of calcination) on the H₂S removal efficiency and impregnated AC yield were investigated. Both responses IAC yield (IACY, %) and removal efficiency (RE, %) were maximized to optimize the IAC preparation conditions. The optimum preparation conditions for IACY and RE were found as follows: calcination temperature of IAC of 880 °C, calcium solution concentration of 49.3% and calcination contact time of 57.6 min, which resulted in 35.8% of IACY and 98.2% RE. In addition, the equilibrium and kinetics of the process were investigated. The adsorbent was characterized using TGA, XRD, FTIR, SEM/EDX, and BET. The maximum monolayer adsorption capacity was found to be 543.47 mg/g. The results recommended that the composite of PKSAC and CaO could be a useful material for H₂S containing wastewater treatment.

We investigated mechanical properties of concretes made with impurity aggregates of different combinations. Besides the mechanisms were explored by EDS, CT, and hardness testing. The results showed that fully rust-stained and surface rust-stained sandstone aggregate had significant adverse impact on the compressive strength of concrete while sandstone aggregate had a much more obvious impact on the ultimate tension of concrete. Concrete crack was more prone to expand along surfaces and the micro-hardness of interfacial transition zone of different aggregates was ranked in decreasing trend as sandstone, slate, SR sandstone, marble, and FR sandstone. The cluster growth of long needle-like ettringite crystal and strong preferential growth trend of Ca(OH)₂ crystals would result in wider interfacial transition zone range of concretes made with fully rust-stained sandstone and marble aggregate, respectively. Therefore, the impurity aggregate content should be strictly controlled during aggregate selection.

In order to investigate water and chloride ion transport in damaged concrete, three types of concrete were prepared, freeze-thawing (F-T) cycling and compressive loading were adopted to induce damage to concrete. Ultrasonic pulse velocity technique was used for evaluating the damage degree of concrete, and the defects of damaged concrete were also detected by X-CT. Water absorption and chloride ion penetrability were used for describing the transport properties of damaged concrete. Effects of damage degree on the water absorption rate and chloride ion penetrability were investigated in detail and the relationships were also established. The results show that the water absorption of concrete makes various responses to damage degree due to the difference of concrete type and damage method. For same concrete with similar damage degree, the water absorption rate of F-T damaged concrete is usually larger than that of concrete damaged by loading. The chloride ion penetrability of damaged concrete increases linearly with increasing damage degree, which is more sensitive to damage degree if the original penetrability of sound concrete is higher.

Silver nanoclusters (NCs) embedded in soda-lime glass was synthesized by the electric fieldassisted diffusion (EFAD) and successive annealing. The samples were characterized by UV-Vis absorption spectroscopy, photoluminescence spectroscopy, X-ray photoelectron spectroscopy (XPS), and lifetime measurements. The experimental results show that the growth of silver clusters is favored by the annealing temperature and dwell time. The as-diffused and annealed glass samples show photoluminescence around 550 nm under UV excitation, which can be associated with the presence of L-center and Ag₃ ⁺ cluster. And the increasing of the annealing temperature and dwell time results in an appearance of the SPR peak and the decreasing of the luminescence intensities because the Ag₃ ⁺ clusters grow up into the Ag nanoparticles.

Hexagonal boron nitride ceramic (h-BN) based on the nitridation of B powders was obtained by reaction sintering method. The effects of sintering temperature on the mechanical properties and microstructure of the resultant products were investigated and the reaction mechanism was discussed. Results showed that the reaction between B and N₂ occurred vigorously at temperatures ranging from 1 000 °C to 1 300 °C, which resulted in the generation of t-BN. When the temperature exceeded 1 450 °C, transformation from t-BN to h-BN began to occur. As the sintering temperature increased, the spherical particles of t-BN gradually transformed into fine sheet particles of h-BN. These particles subsequently displayed a compact arrangement to achieve a more uniform microstructure, thereby increasing the strength.

To reveal the complicated mechanism of the multicomponent mass transfer during the growth of ternary compound semiconductors, a numerical model based on Maxwell-Stefan equations was developed to simulate the Bridgman growth of CdZnTe crystal. The Maxwell-Stefan diffusion coefficients in the melt were estimated. Distributions of Zn, Cd, and Te were calculated with variable ampoule traveling rate and diffusion coefficients. The experimental results show that Zn in melt near the growth interface decreases and diffuses from the bulk melt to the growth interface. For Cd, the situation is just the opposite. The coupling effects of Zn and Cd diffusions result in an uphill diffusion of Te at the beginning of the growth. Throughout the growth, the concentration of Te in the melt keeps low near the growth interface but high far from the growth interface. Increasing the ampoule traveling rate will aggravate the segregation of Zn and Cd, and hence deteriorate the uniformity of Te. We also find that not only the diffusion coefficients but also the ratios between them have significant influence on the species diffusions.

The SO₄ ^2- concentration distributions in surface region of cement mortar immersed in sulfate solution at early stage were measured by layered sampling method combined with chemical analysis, and the diffusion coefficients of SO₄ ^2- anions in surface region of mortar into internal area were calculated by means of instantaneous plane diffusion theory. The experimental results showed that the SO₄ ^2- concentration gradually reduced when the diffusion depth increased in the surface region of mortar. Diffusion coefficient (D) was relevant with the concentration and kind of environmental sulfate solution, which reduced with immersion time at the beginning, and then rose slowly after a period of time. The calculation of initial diffusion coefficient (D ₀) and starting time of deterioration (t_∞) caused by sulfate attack was further attempted based on the data of diffusion coefficient, and it was found that D ₀ and t∞ were all relevant with concentrations of sulfate and different kind of sulfate as well.

In order to distinguish the filling effect and volcanic activity and explore the ways motivating the activity of rich-silicon iron ore tailing(IOT), inert quartz was brought in as the correction standard, the influences of fineness, calcination, thermal curing system and some other factors were investigated by IR, XRD, MIP, and so on microscopic methods. The experimental results show grinding and calcination can only change the amorphous state of SiO₂, and IOT do not have volcanic activity in concrete cured under room temperature condition. Thermal curing systems can stimulate the activity of IOT, especially mortar cured by autoclave curing system can consume a large amount of Ca(OH)₂ and hard calcium silicate and has a closer structure. When the specific surface area of IOT powder is 800 m²/kg, and 30% cement is replaced by IOT powder, the mortar strength with IOT powder is even higher than that with cementonly.

Three kaolinite samples applied for paper coating were collected from America (KA), Brazil (KB), and China (KC), respectively. Parameters such as average bond length of Si-O and Al-O (l_(Si-O) and l_(Al-O)), tetrahedral rotation angles (α), changes of tetrahedral flattening angles (τ) and octahedral flattening angles (ψ) comparative to ideal angle, particle layer thickness (T) and basal z corrugation (Δz) were analyzed by XRD and Rietveld method. The experimental results indicated that Δz _KA > Δz _KC > Δz _KB. KB has a regular structure and KA has a disorder structure, α_KA > α_KC > α_KB, Δτ_KA > Δτ_KC > Δτ_KB, and Δψ_KA> Δψ_KB >Δψ_KC. KA has unstable tetrahedron and octahedron. KB and KC have stable tetrahedron and octahedron, respectively. In the process of manufacture, kaolinite structure may be broken from places with unstable tetrahedron and octahedron. l(Si-O)_KA > l(Si-O)_KB > l(Si-O)_KC and l(Al-O)KA > l(Al-O)_KC > l(Al-O)_KB. What only considered is the effect of bond length, KA may be most easily broken in the manufacture. Compared with bond lengths of KA and KB, Si-O, and Al-O of KB and KC may be easily broken, respectively. T _KA < T _KC < T _KB. KB should be delaminated to finer particles, or it would hinder its dispersibility.

The lattice dynamic, elastic, and thermodynamic properties of BeSe were investigated with first principles calculations. The phase transition pressure from the zinc blende (B3) to the nickel arsenide (B8) structure of BeSe was determined. The elastic stability analysis suggests that the B3 structure BeSe is mechanically stable in the applied pressure range of 0-50 GPa. Our lattice dynamic calculations show that the B3 structure is lattice dynamically stable under high pressure. Within the quasiharmonic approximation, the thermodynamic properties including the constant volume heat capacity and constant pressure heat capacity are predicted.

The effects of four sand contents on the compressive, flexural and splitting-tensile strength of cement mortars were evaluated. Moreover, we experimentally investigated the pore structure of cement mortar brought about by changing the sand content and water/cement ratio. The changes in the pore structure were quantified by measuring the porosity and pore size distribution obtained by using mercury intrusion porosimetry (MIP) technique. The test results show that the strengths of cement mortar increase with increasing sand content. It is also suggested that the traditional water/cement ratio law can be applied to cement mortar with different sand contents, provided that a slight modification is introduced. Sand content is an important parameter influencing the pore structure of cement mortar. Moreover, there is a good relationship between the pore structure and strength of cement mortar.

A novel photocatalytic cement based material was prepared. The distribution of TiO₂ on the surface of cement was characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD), which showed the relationship of photocatalysis and presence of TiO₂. TiO₂ also had an impact on cement hydration, which was studied by thermal analysis. With 300 W UV illuminations, formaldehyde and benzene were degraded efficiently by the prepared photocatalytic cement based materials. 15wt% TiO₂/cement showed the highest degradation efficiency and capability. The results show that formaldehyde and benzene can be degraded within 4 and 9 hours, respectively. Besides, inorganic ions can induce TiO₂ agglomeration. As a result, the presence of inorganic ions in cement is unfavorable for degradation. The photocatalytic cement based materials were fabricated and the degradation efficiency of formaldehyde was measured on building roof under sunlight illumination. Formaldehyde in glass chamber can be degraded thoroughly within 10 days.

We present the specific ab-initio calculations that detail the variations of perovskite BaZrO₃ caused by in-plane strain. Specifically, the internal relaxation, which was not captured in the widely used biaxial strain model, was included in a complementary manner to lattice relaxation. Density functional theory as well as a hybrid functional method based on a plane wave basis set was employed to calculate the lattice structure, elastic constants, electronic properties and optical properties of perovskite BaZrO₃. The lattice parameter c exhibited a clear linear dependence on the imposed in-plane strain, but the Poisson’s ratio caused by internal relaxation was smaller than the elastic deformation, indicating an “inelastic” or “plastic” relaxation manner caused by the introduction of internal relaxation. As a result, the related electronic and optical properties of perovskite BaZrO₃ were also strongly affected by the in-plane strain, which revealed an effective way to adjust the properties of perovskite BaZrO₃ via internal relaxation.

Series Bi₃NbO₇/Bi₂Zn_2/3Nb_4/3O₇ (BN/BZN) composites were synthesized through a facile solid state reaction method. The products were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and UV-vis diffuse reflectance spectroscopy(DRS). When BN: BZN=0.1 mole ratio, the BN/BZN composite showed the best visible-light-driven photocatalytic performance, which decomposed nearly 100% of RhB (10 ppm, pH=3-4) within 40 min. The results demonstrated that in-situ solid state synthesis of BN/BZN composites could be an efficient strategy to develop new photocatalyst for environmental remediation.

The objective of this paper was to develop a comprehensive evaluation method and index to evaluate the performance of sealants and fillers for cracks in asphalt concrete pavements using the method of principal component analysis. The performance experiments including cone penetration, softening point, flow, resilience and tension at low temperature respectively were conducted by reference of ASTM D5329 for eight sealants and fillers often used in China. There by a principal component model was developed and weight of every index was calculated. The experimental results show that there are significantly different performances for sealants and fillers often used in China. Principal component analysis is an objective method that evaluates and selects the performance of sealants and fillers for cracks in asphalt concrete pavements.

To reveal the influence of mechanical activation on the performance of fly ash, the microanalysis (the energy spectroscopy, XRD and SEM), the distribution size of particle of fly ash and cement paste intensity of various age for different grinding time were studied. The relationships of the activity and the composition of fly ash, microstructure and the distribution of particle size by mechanical activation of fly ash were obtained. The internal glass beads with activity were released by grinding fly ash for a certain time. The particle specific surface area was improved and the hydration reaction of the interface and the surface active center was increased by grinding. The granularity distributing of fly-ash trended towards optimization. The polar molecules or ions were easier to intrude into the internal cavity of the vitreous body. The active silica and alumina of fly ash were rapidly depolymerized. Each performance index of fly ash was increased before grinding for 20 min. Cement paste intensity of various age increased along with the grinding time, and the early strength increase range was big, but the later period intensity increase range hastened slightly. The internal part of vitreous of fly ash was destroyed if the fly ash continued to be ground and the activity of fly ash was reduced. It is suggested that Guozhuang's fly ash should be ground for 20 min.

The nanostructure of cementitious materials has important effects on concrete properties. The effects of rice husk ash (RHA) on cement hydration product phases and interfacial transition zone (ITZ) in mortar were investigated from the nano-scale structure perspective. The experimental results indicate that, with the increase of RHA dosages of samples, the volume fraction of high-density calcium-silicate-hydrate (HD C-S-H) in porosity and hydration product phases increases. The volume fractions of HD C-S-H in C-S-H of samples show an increasing trend with the increase of RHA dosages. RHA decreases the thickness of ITZ and increases the matrix elastic moduli of samples, however, the RHA dosoges hardly affect the thickness and elastic moduli.

For refining grain and obtaining excellent properties, the experiments of asymmetric and symmetric monotonic hot rolling were carried out to investigate the role of shear strain on the microstructures and mechanical properties of V-microalloyed steel. The study demonstrates that the gradient ferrite distribution and dispersive pearlite through the sheet thickness are observed in asymmetric rolled specimen, and the homogeneous microstructure with ferrite and large pearlite is found in symmetric rolled specimen. The average grain size in asymmetric rolled specimen is smaller than the one in symmetric rolled specimen. The styles of precipitate morphology in asymmetric rolled specimen are random precipitate and obvious interphase precipitate, while the ones in symmetric rolled specimen are random precipitate and unobvious interphase precipitate. The additional shear strain results in the microstructure difference between asymmetric rolled specimen and symmetric rolled specimen. The impact energy of asymmetric rolled specimen, 58 J, is more than the one of symmetric rolled specimen, 48 J. Both deflection-energy curve and fracture morphology show that the fracture style of asymmetric rolled specimen is ductile, and the ones of symmetric rolled specimen are brittle and ductile.

Two kinds of simulated concrete pore solutions (SPSs) were treated with different amounts of synthetic calcium silicate hydrate (C-S-H). The variation of the [Cl^-]/[OH^-] ratio in SPS was measured and the corrosion susceptibility of carbon steel in the SPS was investigated with potentiodynamic polarization, EIS and weight lose tests. The experimental results showed that for the SPS at pH 12.5, as the amount of C-S-H increases, the [Cl^-]/[OH^-] ratio increases thereby causing an increase in the corrosion susceptibility of the steel. While for the SPS at pH 9.7, with increasing C-S-H amount, the drop amplitudes of both [Cl^-]/[OH^-] ratio and steel corrosion rate first decrease and then increase, and a 3% C-S-H addition shows the best inhibition effect. XPS results demonstrate that after C-S-H treating in pH 12.5 SPS the [Fe³⁺]/[Fe²⁺] ratio in the film on steel surface is reduced while in pH 9.7 SPS the [Fe³⁺]/[Fe²⁺] ratio is increased. The different effects of the C-S-H amount on the two SPSs and the steel corrosion behavior result from the influences of C-S-H on the SPS pH, which is related to the composition of the SPS.

Micro compression and micro extrusion experiments of ultrafine grained titanium cylindrical specimens in diameters of 4, 2, and 1 mm prepared by equal channel angular pressing (ECAP) were conducted on the micro plastic forming test machine. The effects of specimen size, grain size, deformation temperature and extrusion speed on the flow stress and forming properties of the ultrafine grained pure titanium were investigated. The flow stress of ultrafine grained pure titanium specimen decreases with decreasing specimen size. The yield limit of pure titanium with refined grain prepared by ECAP is significantly greater than that of coarse grained specimen. Also the research results show that the flow stress of specimen increases with decreasing deformation temperature and with the increase of the strain rate, and the ultrafine grained pure titanium possesses good micro forming properties at deformation temperature of 300 °C.

We investigated the influences of process parameters on the head curvature of pure titanium sheet in hot rolling process and proposed the controlling means. First, the thermal simulation experiments for pure titanium TA1 were carried out to investigate the hot deformation behaviors of pure titanium in the temperature range of 700-800 °C with strain rate range of 1-20 S^-1, and the processing map was established to determine optimized deformation parameters. Then, the finite element model has been constructed and used to analyze the effect of process parameters on the direction and severity of head curvature of pure titanium sheet. The process parameters considered in the present study include workpiece temperature, work roll diameter, pass reduction, oxide scale thickness of workpiece surface, and interface friction coefficient. The simulation results show that the workpiece temperature and the interface friction coefficient are the two main factors. The proposed controlling means was carried out on a hot rolling production line and solved the head curvature problem effectively. The rolling practices indicate that the rolling yield is improved greatly.

At the initial rolling temperature of 250 to 400 ℃, AZ31B magnesium alloy sheets were hot rolled by four different rolling routes. Microstructures and mechanical properties of the hot-rolled magnesium alloy sheets were analyzed by optical microscope and tensile tests respectively. Based on the Hall-Petch relation, considering the average grain size and grain size distribution, the nonlinear fitting analysis between the tensile strength and average grain size was carried on, and then the prediction model of tensile strength of hot-rolled AZ31B magnesium alloy sheet was established. The results indicate that, by rolling with multi-pass cross rolling, uniform, fine and equiaxial grain microstructures can be produced, the anisotropy of hot-rolled magnesium sheet can also be effectively weakened. Strong correlation was observed between the average grain size and tensile property of the hot-rolled magnesium alloy sheet. Grain size distribution coefficient d _CV was introduced to reflect the dispersion degree about a set of grain size data, and then the Hall-Petch relation was perfected. Ultimately, the prediction accuracy of tensile strength of multi-pass hot-rolled AZ31B magnesium alloy was improved, and the prediction of tensile property can be performed by the model.

The objective of this study was to investigate the effect of a new combined micro/nanoscale implant surface feature on osteoblasts’ behaviors including cell morphology, adhesion, proliferation, differentiation, and mineralization in vitro. A new micro/nano-hybrid topography surface was fabricated on commercial pure titanium (Cp Ti) by a two-step sandblasted acid-etching and subsequent alkali- and heattreatment (SA-AH). The conventional sandblasted/acid-etching (SA) treatment and alkali and heat (AH) treatment were also carried out on the Cp Ti as controls. Surface microstructures of the Ti disc samples were assessed by scanning electron microscopy (SEM). The neonatal rat calvaria-derived osteoblasts were seeded on these discs and the initial cell morphology was evaluated by SEM and immunofluorescence. Initial adhesion of the cells was then assayed by DAPI staining at 1, 2, and 4 h after seeding. The Cell Counting Kit-8 (CCact K8) assay, gene expression of osteoblastic markers (ALP, Col 1, OCN, BSP, OSX, Cbfα1) and Alizarin Red S staining assays were monitored respectively for cell proliferations, differentiation and mineralization. The results show significant differences in osteoblast’s behaviors on the four kinds of Ti surfaces. Compared with Cp Ti surface, the SA and AH treatment can significantly promote cell adhesion, differentiation and mineralization of osteoblasts. In particular, the combined SA and AH treatments exhibit synergistic effects in comparison with the treatment of SA and AH individually, and are more favorable for stimulating a series of osteogenous responses from cell adhesion to mineralization of osteoblasts. In summary, this study provides some new evidence that the integrated micro/nanostructure on the Cp Ti surface may promote bone osseointegration between the Ti implantbone interfaces in vitro.

Fluorenone-based polyamines, as novel light-emitting polymers, were synthesized by the condensation polymerization of 3,6-dibromo-9-fluorenone with different aromatic diamines by palladiumcatalyzed aryl amination reaction. The structures of the polymers were characterized by means of FT-IR, 1H NMR spectroscopy and elemental analysis. The experimental results show a good agreement with the proposed structures. TGA measurement exhibits that the polymers possess good thermal stabilities with high decomposition temperatures (T ₅≥400 °C). Due to the photo-induced intramolecular charge-transfer (ICT) of fluorenone-based polyimines, these polymers show significantly strong photonic luminescence in N,Ndimethylacetamide.

The aim of this study is to investigate the asphalt mixture anisotropy of both the modulus and Poisson’s ratio due to air voids using a discrete element modeling simulation method. Three three-dimensional cubic digital samples of asphalt mixture with different shapes of single air void were built using discrete element software PFC ^3D. The aggregate gradation, air voids and mastic included in the digital samples were modeled using different contact models, with due consideration of the volumetric fractions of the different phases. Laboratory uniaxial complex modulus test and indirect tensile strength test were conducted to obtain material input parameters for numerical modeling. Simulation of the uniaxial cyclic compressive tests was performed on the three cubic samples loaded in three different directions. Dynamic modulus in three directions and Poisson’s ratio in six directions were calculated from the compression stress-strain responses. Results show that both the modulus and Poisson’s ratio are dependent on the preferential orientation of air voids. The anisotropy of the modulus and Poisson’s ratio increases as the pressure loading on the asphalt mixture increases. Compared to the modulus, Poisson’s ratio due to air voids has been shown to be more anisotropic. The maximum of Poisson’s ratio and modulus is shown to be up to 80% and 11% higher than the minimum, respectively.

For the purpose of alleviating the adverse effect of paste aging on the properties of corn starch film, a series of electroneutrally quaternized/sulfosuccinylated starches (EQSS) with different degrees of substitution (DS) were synthesized via the quaternization/sulfosuccination of acid-thinned corn starch (ATS) by varying the amounts of N-(3-chloro-2-hydroxypropl) trimethylammonium chloride, maleic anhydride, and sodium hydrogen sulfite. The influence of paste aging on the properties of starch film cast from heat-induced starch paste was investigated and the properties were explored in terms of tensile strength, elongation, work at break, degree of crystallinity, and flex-fatigue resistance. The experimental results showed that the paste ageing generated adverse influence on the elongation, work at break, and flex-fatigue resistance of starch film. Further experiments showed that electroneutral quaternization/sulfosuccination of starch were able to alleviate the negative effect of paste ageing on the elongation, work at break, and flex-fatigue resistance, thereby obviously enhancing the elongation, work at break and flex-fatigue resistance, and thus reducing the drawback of brittleness. The enhancement depended on the amounts of the substituents introduced. With the increase in DS value, the elongation and work at break as well as flex-fatigue resistance continuously rose, whereas the tensile strength gradually reduced.

Relationship between K₂O-Al₂O₃-SiO₂ system dental glass ceramics and Al₂O₃ ceramics was investigated. 4 groups of glass ceramic with the same components but different thickness (0.8, 1.2, 1.6, and 2.0 mm) were sintered on Al₂O₃ base ceramics according to the same thermal treatment system of leucite micro-crystallization reported in previous literatures. The products of each group were analyzed by polarizing microscope, X-ray diffractometer, and an INSTRON material testing machine. Under the thermal treatment system, leucite crystals were formed in samples of each group, and dispersed evenly. Meanwhile, the compressive strengths of group 3 and group 4 were higher than those of group 1 and group 2. Samples of group 3 showed better mechanical properties than others. The conclusions are drawn that Leucite crystals can be controlled in K₂O-Al₂O₃-SiO₂ system glass ceramic-Al₂O₃ ceramic composite material, and the thickness of glass ceramic has a notable influence on the compressive strength of this ceramic composite material.

We developed poly lactic-co-glycolic acid (PLGA) microspheres loaded with cefquinome and tested their effectiveness in a mouse model. The microspheres were prepared by optimizing several key parameters such as PLGA molecular weight, drug/polymer ratio, internal water volume and ethyl acetate. Drug loading efficiency, stability, in vitro release and tissue distribution in mouse were evaluated. The average particle size of the microspheres was 27.84 μm. The drug loading efficiency was 64.57%. The in vitro release of cefquinome from microspheres after 4 h was about 40% compared with over 90% for the drug alone. The concentration of cefquinome in lung reached 25 μg/g 0.25 h after injection, and kept at 10 μg/g 4 h after injection. However, the concentration of cefquinome was very low in other organs even 0.25 h after injection. In conclusion, Cefquinome-loaded PLGA microspheres are compatible as an effective lung-targeting drug delivery system and have a good sustained release efficacy.