One-dimensional, diluted magnetic semiconductor nanofibers have attracted increasing attention for their unique magnetic properties, large specific surface area, and high porosity. These qualities lead to excellent performance in magneto-optical devices, magnetic resonance imaging, ferrofluids and magnetic separation. The purpose of this study is to fabricate P-type one dimensional CuAlO₂-based diluted magnetic semiconductor nanofibers. First, we fabricated CuAl_0.95Co_0.05O₂ nanofibers with an average diameter of 1 μm with the electrospinning method. The annealed nanofibers were thermally treated at a temperature of 1 100 °C and then shrunk to a diameter of about 650 nm. We used X-ray diffraction measurements and Raman spectra to confirm that the CuAl_0.95Co_0.05O₂ nanofibers had a single impurity free delafossite phase. The X-ray photoelectron spectroscopy analysis indicates that Co was present in the +2 oxidation state, resulting in an room temperature ferromagnetism in the CuAl_0.95Co_0.05O₂ fiber. This contrasts with nonmagnetism in pristine CuAlO₂ fiber. The coercivity (H _c) value of 65.26 Oe and approximate saturation magnetization (M _s) of 0.012 emu/g demonstrate good evidence of ferromagnetism at room temperature for CuAl_0.95Co_0.05O₂ nanofibers.

A new technique to synthesize poly(diphenylsilylenemethylene) (PDPhSM) matrix nanocomposite thin films containing metal nanoparticles such as Ni, Al, Zn, and W produced by pulsed laser ablation has been developed. First, 1,1,3,3-tetraphenyl-1,3-disilacyclobutane (TPDC) films were deposited on 4 cm² silicon substrates cut from c-Si wafers by conventional vacuum evaporation under a pressure of 4.0×10⁻³ Pa; then metal nanoparticles were deposited onto the TPDC films by pulsed laser ablation; finally the TPDC films with metal nanoparticles were heated in an electric furnace in an air atmosphere at 553 K for 10 min to induce ring-opening polymerization of TPDC. The results indicate that it is easy to synthesize metal/PDPhSM nanocomposite thin films by pulsed laser ablation. The morphologies and size of metal nanoparticles are closely related to the kinds of metal. Also, the polymerization efficiency depends on the kinds of metal nanoparticles deposited on the TPDC monomer films by pulsed laser ablation. In addition, The laser ablated metal nanoparticles penetrate into the TPDC monomer films during pulsed laser ablation while the DC sputtered metal nanoparticles just lay on the surface of TPDC films.

Sulfur/graphene composites with different sulfur contents were prepared by two-step synthesis, where graphene was regarded as a carrier of sulfur active substance. The surface structure and crystal form of the composites obtained were characterized and compared by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). It was found that sulfur was partially coated by graphene. The graphene folds provided more nano-pores and electron transport channels for sulfur. From TGA results, the sulfur contents of the sulfur/graphene composites measured were about 42.32 wt%, 54.94 wt%, and 65.23 wt%. Electrochemical tests demonstrated that sulfur/graphene composite (x=54.94 wt%) cathode exhibited better capacity retention (40.13%) compared with the pure cathode (20.46%), where an initial discharge capacity was up to 1 500 mAh·g⁻¹ and it remained about 600 mAh·g⁻¹ after 30 cycles. Furthermore, the electrochemical reaction mechanism and the state of reaction interface for Li/S battery were analyzed by cyclic voltammogram and AC-impedance spectra. The results indicated that the sulfur/graphene composite with a sulfur content of 54.94 wt%, based on a two-step synthesis, contributed to improving electrochemical properties of lithium/sulfur battery

Pr³⁺ doped ZnO quantum dots (QDs) were successfully synthesized by sol-gel process. X-ray diffraction (XRD) and X-ray Phtoelectron spectroscopy (XPS) were used to analyze the microstructure variation of ZnO QDs and the chemical environment of Pr³⁺ with increasing Pr³⁺ doping concentrations. Most of Pr³⁺ ions distribute on the surface of ZnO QDs while a few of them penetrate into the ZnO lattice to substitute Zn²⁺ which causes the lattice distortion and the change of the crystal size. With increasing concentration of Pr³⁺ ions, the crystal size of ZnO QDs firstly increases and then decreases meanwhile the amorphization gradually increases. New Pr-O-Zn bonds formed after Pr³⁺ doping and Pr³⁺ ions have at least two chemical bonding environments: one is Pr-O-Zn bond and the other is Pr-O bond surrounded by oxygen vacancies.

The effect of TiO₂ on the crystallization behaviors of the glass ceramics prepared from granite tailings was investigated by differential scanning calorimetry (DSC), X-ray diffraction (XRD), and field emission scanning electron microscopy (FESEM). The results showed that the crystallization peak temperature decreased firstly, and then increased with the increase of TiO₂ content. The optimum addition amount of TiO₂ was 8 wt%. With a single-step heat treatment at 924 °C for 1 h, augite precipitated as the only crystalline phase both on the surface and in the interior. The avrami parameter of the sample was 3.25, suggesting a two-dimensional crystallization mechanism. The activation energies for phase separation and crystallization of augite were 321.75 and 698.83 kJ/mol, respectively.

The in-situ synthesized mullite bonded SiC ceramics for solar thermal tower plant were prepared from Silicon carbide (SiC), manufactured aluminum hydroxide (Al(OH)₃) and Suzhou kaolin via semi-dry pressing and pressureless firing. The results indicate that sample B3 (designed mullite content 15 wt%) fired at 1 400 °C exhibited optimal performance with a bending strength of 97.41 MPa. Sample B3 can withstand 30-cycles thermal shock without cracking (wind cooling from 1 100 °C to room temperature), and the bending strength after thermal shock decreased by 17.92%. When the service temperature is 600 °C, the thermal diffusivity, specific heat capacity, thermal conductivity and heat capacity are 6.48×10⁻² cm²·s⁻¹, 0.69 kJ·kg⁻¹· K⁻¹, 9.62 W·m⁻¹·K⁻¹ and 977.76 kJ·kg⁻¹, respectively. The XRD and SEM results show that SiC, mullite, α-quartz, and tridymite are connected closely, which gives the material a good bending strength. After 30-time thermal shock cycles, the structure of samples becomes loose. SiC grains are intersectingly arranged with rodshape mullite, exhibiting a favorable thermal shock resistance. The addition of Al(OH)₃ and Suzhou kaolin can accelerate the synthesis of mullite, thus to reduce the firing temperature effectively. The volume effect of tridymite is relatively small, improving the thermal shock resistance of materials. A higher designed mullite content yields a lower loss rate of bending strength. The mullite content should not be more than 15 wt% or else the bending strength would be diminished.

Erbium dihydride thin films were prepared by pulsed laser deposition on Si(100) substrates using erbium target under different low hydrogen pressures. The properties of these films were examined by atomic force microscopy, X-ray diffractometer, transmission electron microscopy, and Fourier transform infrared spectroscopy and UV-vis spectroscopy. Surface morphology reveals the smooth surface of these films (RMS: from 0.503 to 2.849 nm). The presence of obviously-broadened peaks for diffraction planes (111) suggests a presence of very tiny crystallites distributed along a preferred crystallographic orientation. Transmission electron microscopy investigations confirmed the formation of tiny crystallites due to the implantation of erbium ions. Due to the increase of nominal H concentration, the intensity of the broad absorbance from 190–260 nm increased.

The hybrid films of low-density polyethylene (LDPE) embedded with zinc oxide (ZnO) particles were prepared by melt-blending process. X-ray diffraction (XRD) results illustrate that ZnO particles are distributed in the LDPE matrix and FTIR results show that no chemical bonds form between ZnO particles and LDPE matrix. The measurements of the dielectric properties of the hybrid films show that the dielectric constant of the composites reinforces and dielectric loss increases with increasing ZnO weight fraction. Moreover, the thermal properties of the LDPE/ZnO hybrid films are improved and the results of optical properties studied by ultraviolet-visible (UV-Vis) spectrometer show that the inclusion of ZnO particles can improve the anti-UV properties of the films. The improvements of the dielectric, optical and thermal properties demonstrate that the hybrid film will be a promising material in the food package and engineering fields.

The energy band-gap and related factors of tantalum pentoxide with hexagonal phase were investigated using hybrid functional B3LYP and sX-LDA methods. The results showed that both sX-LDA and B3LYP techniques reveal the indirect semiconductor nature of δ-Ta₂O₅, whereas the obtained value of energy band-gap is much higher than previous theoretical reports but closer to the experimental data. The optical bandgap of δ-Ta₂O₅ is expected to originate from the O 2p→Ta 5d transition which may benefit from the d-s-p hybridization.

A novel core-shell structure Ag@Al₂O₃ nano-particles were synthesized and doped into polyimide as conductive fillers to prepare the composite films with high dielectric properties and low dielectric loss. The morphology and structures of the Ag@Al₂O₃ nano-particles were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), and UV-visible spectroscopy. All the results proved that the Ag@Al₂O₃ nano-particles had a typical core-shell structure, for the Ag particles were coated by Al₂O₃ shell and the average sizes of Ag@Al₂O₃ particles were between 30 to 150 nm. The as-prepared Ag@Al₂O₃ nanoparticles were doped into the polyimide with different mass fractions to fabricate the Ag@Al₂O₃/PI composite films via in-situ polymerization process. SEM analysis of composite films showed that the Ag@Al₂O₃ nanoparticles homogeneously dispersed in polyimide matrix with nanoscale. As dielectric materials for electronic packaging systems, the Ag@Al₂O₃/PI composites exhibited appropriate mechanical properties and enhanced dielectric properties, including greatly enhanced dielectric constant and just a slight increase in dielectric loss. These improvements were attributed to the core-shell structure of fillers and their fine dispersion in the PI matrix.

This work aimed to analyze the glass material used for sealing the end of a thermal collector in a parabolic trough solar power plant. Based on matched sealing requirements and application performance of glass and Kovar alloy 4J29, one borosilicate glass material (GD480S), whose expansion coefficient was similar to that of Kovar alloy 4J29, was studied. Moreover, the effect of the ratio of SiO₂ to B₂O₃ on the glass properties was explored in detail by Fourier transform infrared spectroscopy. As the SiO₂ to B₂O₃ ratio in the glass increased from 4.18 to 5.77, the expansion coefficient showed a decreasing trend from 4.95×10⁻⁶/°C to 4.55×10⁻⁶/°C. In addition, the water resistance performance improved, enabling the glass material to seal well with the alloy for application in a trough solar power plant. Thus, the increase in the SiO₂ to B₂O₃ ratio made the glass structure more compact and improved the glass performance to meet the requirements of an industrial tubular receiver.

A rapid-heating method in the absence of electric/magnetic field was achieved by introducing a self-propagating-combustion (SHS) as heating source. The effect of heating rate on the alumina grain growth was explored based on this rapid-heating method. Comparing with the alumina prepared by two different heating ratios (greater than 1 000 °C/min in SHS and about 50 °C/min in common pressureless sintering furnace), it was revealed that the rapid heating could promote the grain growth greatly without pressure during sintering. However, if a pressure was applied simultaneously, the grain growth would be almost completely restrained. Since these observations are quite different from the expectation, a new grain growth model was proposed.

An adequate hardness of MoS₂/Cu composites has not been achieved if these materials are applied under the extreme wear conditions. Therefore, Mo-reinforced MoS₂/Cu composites were prepared by powder metallurgy (P/M) methods. The electrical sliding wear properties in the absence or presence of Mo-reinforced MoS₂/Cu composites were tested by HST-100 high speed electric-tribometer. The hardness, electrical conductivity, density, and microstructure of MoS₂/Cu composites were observed. Mo-reinforcement MoS₂/Cu composites are of good electrical conductivity, while the hardness of Mo-reinforcedment MoS₂/Cu composites is about 33.3% higher than that of MoS₂/Cu composites. With the addition of Mo, composites show better wear properties under high speed and large electric current due to the improvement of hardness. The effects of current intensity and sliding velocity on the wear properties of the tested materials are complicated, and the wear mechanisms of MoS₂/Cu composites are mainly abrasive wear and adhesive wear with arc erosion.

Highly oriented calcium carbonate lamellas are exquisite structure produced by biomineralization. Strategies mimicking nature have been developed to synthesize inorganic materials with excellent structures and optimal properties. In our strategy, egg white protein and zinc ion were employed in the solution to induce the crystallization of calcium carbonate, resulting in the macroscopic aragonite laminate with an average length of 1.5 mm, which was comprised of single-crystalline tablets. During the crystallization at initial stage, it was found that the particles displayed the characteristics of amorphous calcium carbonate, which was then transformed into the sophisticated structured aragonite through a multistage assembly process. The rebuilt nacre structure in vitro was achieved owing to the synergistic effects of egg white protein and zinc ion.

Crystalline metal-organic framework cobalt (II) benzenetricarboxylate Co₃(BTC)₂·12H₂O (MOF-Co) has been prepared using solvothermal method. The reaction of cobalt (II) nitrate and 1,3,5-benzenetricarboxylic (BTC) acid in a mixed solution of N,N-dimethylformamide (DMF)/C₂H₅OH/H₂O (1:1:1, v/v) at low temperature for short reaction times produced this crystalline compound. Compared with traditional hydrothermal method, a mixed solution method for the synthesis of crystalline metal complex was found to be highly efficient. After water molecules were removed from this metal complex, its exposed nodes served as active sites. When this MOF-Co was employed in the oxidation of CO, it showed good catalytic properties causing 100% conversion of CO to CO₂ at low temperature of 160 °C.

The synthesis of Friedel’s salt (FS: 3CaO·A1₂O₃·CaCl₂·10H₂O) by the reaction of calcium chloride with sodium aluminate was investigated. Factors affecting the preparation of Friedel’s salt, such as reaction temperature, initial concentration, titration speed, aging time and molar Ca/Al ratio were studied in detail. XRD, SEM images and particle size distribution show that the reaction temperature, aging time and molar Ca/Al ratio have significant effect on the composition, crystal morphology, and average particle size of the obtained samples. In addition, the initial CaCl₂ concentration and NaAlO₂ titration speed do not significantly influence the morphology and particle size distribution of Friedel’s salt. With the optimization of the operating conditions, the crystals can grow up to a average size of about 28 μm, showing flat hexagonal (or pseudo-hexagonal) crystal morphology. Moreover, two potential mechanisms of Friedel’s salt formation including adsorption mechanism and anion-exchange mechanism were discussed. In the adsorption mechanism, Friedel’s salt forms due to the adsorption of the bulk Cl⁻ ions present in the solution into the interlayers of the principal layers, [Ca₂Al(OH⁻)₆·2H₂O]⁺, in order to balance the charge. In the anion-exchange mechanism, the free-chloride ions bind with the AFm (a family of hydrated compounds found in cement) hydrates to form Friedel’s salt by anion-exchange with the ions present in the interlayers of the principal layer, [Ca₂Al(OH⁻)₆·2H₂O]⁺-OH⁻.

We put forward a new approach for the synthesis of Ag@AgCl plasmonic photocatalyst via a hydrothermal-deposition-photoreduction method. The cetylmethylammonium chloride (CTAC) was used alone as both a source of reactants and surfactant. The structure of the prepared photocatalyst was determined by XRD, SEM, EDX and UV-Vis spectroscoscopy. The photocatalytic properties were investigated by degradation of an organic pollutant, Rhodamine B, under visible light irradiation. The results reveal that the experimental conditions have a great effect on the morphology of Ag@AgCl crystals. Ag@AgCl crystal is cubic and the Ag@AgCl sample which is photoreduced for 40 min exhibits the highest photoactivity, and 80.6 % RhB is degraded after irradiation for 2 hours using this catalyst. The high photocatalytic activity observed is attributed to the surface plasmon resonance effect of Ag nanoparticles.

Copper oxide thin films were prepared by a direct-current magnetron sputtering method followed by a thermal annealing treatment at 100–500 °C. The obtained films were characterized by X-ray diffraction, UV-vis absorption spectroscopy, scanning electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy. With the increase of the annealing temperature, it was found that the films transformed sequentially from amorphous to single-phase Cu (100 °C), mixed-phase of Cu and Cu₂O (150 °C), single-phase Cu₂O (200 °C), then to mixed-phase of Cu₂O and CuO (300 °C), and finally to single-phase CuO (400–500 °C). Further analyses indicated that the Cu/Cu₂O thin films and the Cu₂O thin films presented no further oxidation even on the surface in air atmosphere. Additionally, the visible-light photocatalytic behavior of the copper oxide thin films on the degradation of methylene blue (MB) was also investigated, indicating that the films with pure Cu₂O phase or Cu/Cu₂O mixed phases have excellent photocatalytic efficiencies.

New phosphors Sr₂ZnSi₂O₇: M (M=Mn²⁺, Tb³⁺) were synthesized through solid-state reaction, and their photoluminescent properties under UV and VUV region were investigated. The results showed that Sr₂ZnSi₂O₇:Mn²⁺ emitted green light with the strongest emission peak centered at 525 nm, and its quenching concentration under 254 and 147 nm excitation occurred at x = 0.08 and 0.06, respectively. Sr₂ZnSi₂O₇: Tb³⁺ emitted green light with the strongest emission peak centered at 541 nm, and its quenching concentration under 254 and 147 nm excitation also appeared at y = 0.25. At 147 nm excitation, the emission intensities of Sr₂Zn_0.94Si₂O₇: 0.06Mn²⁺ and Sr_1.75ZnSi₂O₇: 0.25Tb³⁺ phosphors were 54% and 36% of that of Zn_1.96SiO₄:0.04Mn²⁺, respectively. And their decay times (τ_1/e) were about 3.18 ms and 3.9 ms, respectively.

Residual stresses and deformation of static bonding multi-layer Pyrex7740 glass and aluminum have important effects on performances of bonding parts. The stress and strain finite element analysis of anodic bonding can optimize the structure and process design, reduce the workload of the experiments, shorten the production cycle, improve the bonding quality, and reduce the process costs. In this paper, residual stresses and deformation in the static bonding two-layer (glass/aluminum), three-layer (glass/aluminum/glass), five-layer(glass/aluminum/glass/aluminum/glass)and seven-layer (glass/aluminum/glass/aluminum/glass/aluminum/glass) samples have been analyzed using nonlinear finite element simulation software MARC. The simulation results show that the shear stress distribution and deformation distribution in different multi-layer glass and aluminum samples are similar. The stress distribution along thickness at different typical positions in all multi-layer samples has characteristics of pulse pattern, which has pulse peak at the position of transition layers and then decreases abruptly to the minimum value at the positions of glass and aluminum. The maximum shear stress is located in the outside surface area in the transition layer between the top unconstrained glass layer and aluminum layer. The displacement distribution along thickness in all multi-layer samples increases gradually from the constrained bottom glass layer to the top unconstrained glass layer with abrupt step increase in the aluminum layers. The maximum deformations occur in aluminum layers. It is found that the minimum deformation distortion and the minimum shear stress occur in the three-layer static bonding sample.

An appropriate proportion of alkali activated slag cement, abbreviated as AASC later, was determined based on strength test of paste specimens. Results showed that AASC prepared from 14% low modulus water glass and blast furnace slag presented its compressive strength of hardened cement paste of 69.6, 84.0 and 91.8 MPa at 3, 7, and 28 d curing ages respectively. Flowability of the fresh tailings-cement pastes and the strength development of hardened tailings-cement paste were also tested both in the cases with addition of AASC and Portland cement. The fresh tailings-cement paste added with AASC presented much better flowability and the corresponding hardened paste presented higher compressive strength, especially the long term strength, than those added with Portland cement. Therefore, tailings paste added with AASC allowed lager solid content than that of Portland cement in order to keep the similar flowability. SEM observation on the microstructure of the hardened tailings-AASC mixture pastes showed obvious cementation effect. MIP measurements also showed that the total porosity of the hardened tailings-cement pastes decreased, and the portion of larger pore also decreased when the dosage of AASC increased. It is believed that AASC is more suitable to be used as a binder for the stabilization of zinc-lead tailings and for its backfilling operation than Portland cement.

A self-made AMPS-modified polyacrylic acid superplasticizer and two others of the same type but with different molecular structures, which are commercially available, are used in this study to investigate the effect of a 2-acrylamide-2-methyl propylene sulfonic (AMPS)-modified polyacrylic acid superplasticizer on the properties of cement-based materials. In the experiments, initial fluidity, 1 and 2 h fluidity over time after admixtion, bleeding rate of the net cement mortar, and adsorption capacity and rate of cement particles are determined by adding different dosages of the three superplasticizers into the cement paste to characterize the dispersivity and the dispersion retention capability of each superplasticizer. Water-reducing rates of three kinds of mortars are simultaneously determined to characterize the water-reducing capacity of each superplasticizer, as well as the 3 and 28 d compressive strengths to characterize the compression resistance. Results show that water-reducing effect and fluidity better maintain the capability of the AMPS-modified polyacrylic acid superplasticizer than the two commercially available polyacrylic acid superplasticizers, and the compressive strengths after 3 and 28 d show significant growth. In conclusion, the effects of water reduction and strengthening of the AMPS-modified polyacrylic acid superplasticizer are evidently better than those of the two commercially available polyacrylic acid superplasticizers.

The chemical and physical interactions in the interfacial transition zone (ITZ) between three different types of coarse aggregates (limestone, granite and basalt) and cement paste were investigated. The results show that all the aggregates are chemically active. Significant amounts of Ca²⁺, K⁺, and Na⁺ are absorbed by all the aggregates from the cement solution, granite and basalt also absorb significant amounts of OH⁻ and release significant amounts of Si⁴⁺ into cement solution. The XRD, EDXA and pore structure results of the ITZ also show that more clinkers participate in the cement hydration in the ITZ of granite and basalt, and more hydrates are generated, hence resulting in a denser ITZ structure with a lower content of macropores. Although the limestone has the least activity, the connection between it and cement paste is tight, due to its rough surface and higher water absorption. Whereas the granite with smooth surface and lower water absorption has a loose connection with cement paste, many pores and cracks are visible, which is very detrimental to the concrete durability.

Polymer modification in the field of construction engineering has a history nearly 90 years. Mechanical properties, water resistance, chemical resistance and durability to some extent have been improved by different polymer modification although those modifications are classified into physical modification. To obtain better performance of cementitious materials, chemical modifications have been tested. In this study, epoxy has been designed as a predominant modifier in the modified system with its corresponding hardener. Amino sulfonate, the additive, has been used to improve the system’s workability. Functional silane, as it has special functional groups, was used to set up the connections among epoxy, cement moiety and amino sulfonate. The investigation carried out by IR, Raman spectroscopy, DSC and NMR reveals that the chemical connections have been set up among all the components in the modified system. Flexural tests results present the good effect of the chemical modification as the flexural strength and strain have been improved substantially.

Physical and mechanical properties variations of lithium slag were systematically investigated by three different ways such as physical, chemical activation, physical-chemical combined activation. Mechanisms of the cementitious properties and hydration process of lithium slag composite cement were studied by XRD and SEM. The results showed that specific surface area increased from 254 to 700 m²/kg while median particle size decreased from 14.97 to 8.45 um with the increase of grinding time. Physical, chemical activation and combined activation improved the strength and hydration degree of lithium slag composite cement. Compared with original lithium slag, the flexural strength and compressive strength of mortars were improved significantly with the increase of grinding time. A higher strength of the cement with the lithium slag was attained; The sample with 10% lithium slag got the highest strength when the grinding time was 10 min; the compressive strength was higher than OPC at 28 days, which increased by 12.3%. When the Na₂SO₄ content was 0.6%, the compressive strength increased by 1.4%; when the Al₂(SO₄)₃·18H₂O content was 0.4%, the compressive strength increased by 5.8% at 28 days. Compared with the late strength, the improving degree of early strength was larger with the incorporation of activator. The results of XRD and SEM were consistent with the results of mechanical properties; it is also evident that lithium slag composite cement hydration products were mainly AFt, Ca(OH)₂, CaSO₄·2H₂O, and C-S-H gel.

Effects of modified triethanolamine as cement grinding aids on particles characteristics and mechanical property of cement were studied, and its reaction mechanism was analyzed by IR, Zeta potential, SEM, XRD and TG-DTA. The results show that the content of 3–32 μm particles for cement with 0.015% modified triethanolamine(M-TEA) is increased by 12.4%, and the compressive strengths of cement with 0.03% M-TEA are increased by 5.5 and 8.2 MPa at 3 and 28 days, respectively. And both the grinding and enhancement effects of M-TEA on cement are better than triethanolamine. The mechanism analysis shows that M-TEA not only has the amino and hydroxyl groups of TEA, but also has the ester, carbonyl, carboxyl groups which easily combine with metal ions of cement minerals, resulting in that M-TEA can promote surface adsorption and shield the unsaturated charges in the surface and crack section of particles, thus particles reunion is prevented and grinding efficiency is improved. Enhancement of M-TEA on cement mainly lies in that it can promote or induce hydration reaction of cement mineral with gypsum and water, which accelerates formation of hydration products, and then improves the structure and morphology of cement hydration products, thus the uniformity and compactness of product structure is increased.

AC impedance is a new method to study the changes of pore structure and the hydration degree during the hydration and hardening process of cement paste by the change of the electrochemical parameters. Employing AC impedance method, we studied the hydration and hardening process of cement paste with fly ash and slag, and analyzed the influence of different hydration age, water-binder ratio and mineral admixture on the impedance parameters. Moreover, we compared the results with those by the conventional porosity testing method and X-ray diffraction method. The results showed that AC impedance could be taken as a new technology in cement and concrete research.

Dissolution of cement clinker minerals involves a number of physical and chemical processes, and the simulation of dissolution processes helps to understand cement hydration conveniently. Dissolution model of cement clinker minerals was set up based on simulation theory of geochemical reaction equilibrium, PHREEQC simulation software provided by United States Geological Survey (USGS) was employed for thermodynamic calculation of C-S-H system. Stability of C-S-H system with low Ca/Si ratio at normal temperature was also explored. The results show that many phase assemblages coexist with the aqueous phase depending on its composition. The most stable product varies with different Ca/Si ratio of C-S-H system. Active SiO₂ will consume excessive CH, so the Ca/Si ratios of C-S-H system decrease, C-S-H with low Ca/Si ratio becomes the most stable product, and this is the thermodynamic driving force of secondary pozzolanic reaction.

In-situ observation of microstructural evolution during heating and soaking process was carried out for a high nickel steel using HTCLSM. Dark phases were observed when soaking at 900 °C. Results showed that the number of the dark phases culminated in about 50 s during soaking at 900 °C. With the increase of soaking time the area proportion of the dark phases increased and reached the maximum value in about 3 min. When temperature rose from 900 °C, the dark phases remained steady initially, but started to dissolve into the matrix at about 1 060 °C and completely disappeared at 1 132 °C. When the specimen soaked at 900 °C was cooled down to room temperature (RT), the dark phases kept stable. Energy spectrum analysis results showed that the dark phases contained much more Cr and Mn elements than the matrix and were also rich in V. Tensile test results showed that the dark phase strengthened the steel with the maximum tensile strength obtained after soaking at 900 °C for 3 minutes.

Continuous annealing simulation tests were conducted by using a continuous annealing thermomechanical simulator. Holding times of 5, 60, 180, and 480 seconds for an intercritical annealing temperature of 820 °C were adopted to investigate the evolution of the microstructure and mechanical properties of ferrite-bainite dual-phase steel. The ferrite-bainite dual-phase steel was characterized by high strength and low yield ratio due to the presence of the constituents (polygonal ferrite, bainite, martensite and retained austenite) of the steel microstructure. Specimen 3 exhibits the highest value of A50 (7.67%) and a product of R _m × A ₅₀ (10453MPa%) after a 180s holding. This is likely attributed to the presence of a C-enriched retained austenite in the microstructure. And the effect of martensite islands and carbide precipitate is thought to be able to contribute in strengthening the present steel. It is expected that equilibrium of austenite fraction would be reached for reasonable intercritical holding period, regardless of the heating temperature. The results suggest that long increasing holding times may not be needed because the major phase of the microstructure does not change very significantly. It is favorable for industrial production of DP steels to shorten holding times.

The rheological behavior of semi-solid AZ91D magnesium alloy was investigated in isothermal steady state condition. The effects of stirring temperature and shearing rate on apparent viscosity of semi-solid alloy slurry at steady state were discussed. The results show that the apparent viscosity of semisolid AZ91D alloy increases with increasing solid fraction. It increases slightly before the solid fraction reaches a certain value, about 0.4, and then goes up rapidly after the solid fraction reaches the critical value. However, the apparent viscosity decreases with increasing shearing rate, and the reduction amplitude is higher when the solid fraction is higher. According to the experimental data, an empirical equation that shows the effect of solid fraction and shearing rate on the apparent viscosity of semi-solid AZ91D alloy can be built as η _a=9.7×10⁻²exp(13.87f _s)γ^−0.58.

The casting and annealing technologies were applied to fabricate the La_0.8Mg_0.2Ni_3.3Co_0.2Si _x (x = 0–0.2) electrode alloys. The effects of Si content and annealing temperature on the structure and electrochemical performances of the alloys were investigated systematically. The analyses of XRD and SEM show that all the alloys possess a multiphase structure, involving two main phases (La, Mg)₂Ni₇ and LaNi₅ as well as a residual phase LaNi₃. The addition of Si brings on an evident increase in the LaNi₅ phase and a decrease in the (La, Mg)₂Ni₇ phase, without altering the main phase component of the alloy, which also makes the lattice constants and cell volumes of the alloy enlarged. Likewise, the annealing treatment engenders the same action on the lattice constants and cell volumes as adding Si. Simultaneously, it gives rise to the variation of the phase abundance and the coarsening of the alloy grains. The electrochemical measurements indicate that the addition of Si ameliorates the cycle stability of the as-cast and annealed alloys significantly, but impairs their discharge capacities clearly. Similarly, the annealing treatment makes a positive contribution to the cycle stability of the alloy evidently, and the discharge capacity of the alloy shows a maximum value with annealing temperature rising. Furthermore, the high rate discharge ability (HRD) first augments and then declines with the rising of Si content and annealing temperature.

The phenolic emulsifiers used in emulsified asphalt of micro-surfacing, which was the most important tools in the road maintenance, were investigated by control technology. Many factors influencing this reaction were studied and three kinds of phenolic emulsifiers were prepared without catalyst in ethanol. The performance was researched that 2-({2-[2-(2-Amino-ethylamino)-ethylamino]-ethyl-amino}-methyl)-4-nonyl-phenol (abbreviated as TETA) could be used in micro-surface. With addition of 0.5 % demulsifier, the mixing time was extended to 120 seconds obviously, and the cohesion torque (60 min) was 2.8 N*m, which satisfied the opening traffic time shorter than 1 h. The wet track abrasion (6 d) was lower than 807 g/m², with interfacial modifier added, but the load wheel was increased with interfacial modifier increasing. When the TETA: demulsifier: interfacial modifier =3:1:3, excellent performance was obtained and the experimental results met the International Slurry Surfacing Association (ISSA) standard. The synthesis process of this emulsifier is simple and the performance used in micro-surface was excellent, so this kind of emulsifier could have a better application future.

Compressive and sealing characteristics of PTFE under cyclic loading-unloading at room temperature are studied in order to evaluate the cyclic sealing performance of control valve comprehensively. The unloading characteristics are different from the loading ones, therefore there is hysteresis between the unloading and loading curves. Compressive hysteresis is the main factor that causes sealing hysteresis. The leakage rate of PTFE complies with the power law before it enters the relatively stable region. Lastly, the effect of working pressure on the compressive and sealing characteristics is discussed. The experimental results show that the working pressure has little effect on compressive deformation but has a great influence on leakage rate.

Sodium bentonite, graphite, light calcium carbonate and diatomite were used as parent minerals for the mineral-based porous granulated material (MPGM) which was tested for the removal of methyl orange (MO), a cationic dye, from aqueous solution. The adsorption capacity was evaluated under the conditions of varied initial pH, adsorbent dosage, dye concentration, temperature, reaction time, and static regeneration. Experimental results showed that the maximum capacity of MPGM adsorbing MO was more than 80 mg·g⁻¹. The adsorption equilibrium and kinetics of MPGM followed typical pseudo-first-order and Langmuir adsorption models respectively. The thermodynamic parameters of ΔG ^○, ΔH ^○ and ΔS ^○ showed that the adsorption was an endothermic and spontaneous process without remarkable change. The spent MPGM was regenerated 5 times and probable pathway for the efficient and re-utilizing adsorbent has been proposed. The results indicate that MPGM has a structure of silicon-aluminium-calcium-carbon, and could be employed as porous, low density, and large specific surface area alternatives for the removal of cations dyes from industrial wastewater.

To investigate the effects of polyethylene glycol cross-linking on the mechanical properties, 80 porcine aortic valves were harvested, decellularized, and introduced with sulfhydryl. Then the valves were randomly assigned into 5 experimental groups and 1 control group (n=16). For the valves in those experimental groups, branched polyethylene glycol diacrylate (PEG) of 5 different molecular weights (3.4, 8, 12, 20, 40 kDa) were synthesized and cross-linked with them respectively. The efficiency of the cross-linking was determined by measuring the amount of residual thiol group and the mechanical properties of the cross-linked valve leaflets were assessed by uni-axial planar tensile testing. The efficiency of the PEG 20 kDa group was 70.72±2.33%, obviously superior to that of the other groups (p<0.05). Tensile test proved that branched PEG cross-linking can significantly enhance the mechanical behaviors of the decellularized valve leaflet and the Young’s modulus of each group was positively correlated with the molecular weight of PEG. It was concluded that branched PEG with the molecular weight of 20 kDa can effectively cross-link the decellularized porcine aortic valves and improve their mechanical properties, which makes it a promising cross-linker that can be used in the modification of decellularized tissue engineering valves.

Ramie fiber (RF) was used to reinforce the polypropylene (PP). The composites were prepared with a melting hybrid technology. Tests had been performed on PP and composites with different RF contents (10 wt%, 20 wt%, and 30 wt%). By using SEM, DSC, TGA, electronic universal testing machine, HDT-VICAT tester and coefficient of linear expansion tester, the effects of the RF loading were assessed on the basis of morphologies, mechanical and thermal properties as well as vicat softening temperature and CTE of the resulting composites. The results show that the thermal degradation temperature of the PP/RF composites becomes lower with higher fiber content. The crystallization rate of the PP matrix is accelerated by the unmodified RF. Because of the inferior interfacial bonding strength between RF and PP, the tensile strength of composites decreases by the presence of RF. And the RF used is relatively long compared with the diameter, the impact strength of the composites is improved by the unmodified RF. The vicat softening temperature of composites can be increased by about 5 °C in the presence of RF compared with PP. The CTE is reduced significantly in the presence of RF. Generally speaking, impact strength, crystallization rate, vicat softening temperature and CTE of PP/RF composites could be improved in the presence of RF. The tensile strength is decreased and thermal degradation temperature of composites becomes lower, but these should not affect most subsequent normal uses of the composites. As the unmodified RF is used directly, no hazardous waste is produced during the fabrication process, combined with the low price, so, a facile and economic preparation pathway is given by using unmodified natural fiber to reinforce polymer and composites with good performance obtained.

The objective of this study was to investigate the effects of mineralized bone nodules, formed in vitro by bone marrow stromal cells (BMSCs), on the new bone formation in bone defect and on implant surface. The mineralized bone nodules were generated by culture of Lewis rats BMSCs on titanium disks in osteogenic induction medium. The gap-healing animal model was used to create the bone defect facing the disk. The titanium disks in the presence of B group or in the absence of NB group bone nodules were randomly placed into one of the rat distal femurs. This self-control design was used to compare the bone formation in defects and on titanium surface, by Micro-CT, fluorescence staining, histological and histomorphometric analysis. The new bone formation parameters in bone defect area of B group were significantly higher than those of NB group at 2 weeks, including bone volume fraction, trabecular thickness and bone area ratio. The bone nodules pre-stained with Alizarin red disappeared mostly at 2 weeks, while the red fluorescence reappeared in the newly formed bone away from the disk surface. For the bone-implant contact, B group showed lower values than NB group at 2 weeks, but no significant difference was found at 4 weeks. Our results indicate that the mineralized bone nodules can be resorbed in vivo and promote the early osteogenesis in the bone defects, and bone nodules may be applicable for new bone generation in bone defect or modification of tissue engineering scaffold.

The stability parameters of implants (ITV, ISQ & PTV) according to different sizes of controlled bone defects made in implant osteotomies were analyzed and the correlation among the three kinds of implant stability parameters was tested in this study. 45 tapped screw-type dental implants were inserted in three types of implant osteotomies made in 8 fresh-frozen pig femoral bones: Type1 — without coronal bone defect, Type2 — with 3 mm coronal bone defects, and Type3 — with 6 mm coronal bone defects. The insertion torque values, ISQ & PTV of implants were measured and analyzed statistically. It is concluded that the circumferential coronal bone defects statistically influence the primary stability of implants; ITV, ISQ and PTV are suitable and available to detect the peri-implant coronal bone defects in 3 mm increments, and ITV and PTV are more sensitive to coronal cortical bone loss. There was a strong correlation between ITV and ISQ.