The microstructures, components, thermal stability, specific heat capacity and thermal conductivity of basalt sample were studied. Besides, as a comprehensive result of thermal expansion and contraction process, both the friction coefficient and wear rate of the basalt sample were also characterized. Our results indicate that basalt is an excellent candidate to be used as thermal energy storage material for concentrated solar power plants, and also provide a strategy for solar energy utilization in volcanic area with excellent geographical environment.

A film with “brick-and-mortar” structure was prepared by layer-by-layer (LBL) technique using polyvinyl alcohol (PVA) and polymethyl methacrylate (PMMA) as the flexible material or “mortar” and mica as the rigid material or “brick”. The film deposited on a glass slide after self-assembly cycles had a thickness of 3 µm thick and an uneven, wavy surface. The film exhibits enhanced mechanical properties, i e, the hardness and indentation modulus values could reach 6.14 and 68.41 GPa, respectively. The hardness and elastic toughness were found to be depended on three factors, i e, the ratio of PVA to mica, the number of self-assembly cycles, and the pretreatment method of the mica suspension. The self-assembly process was driven by formation of the hydrogen bonds between the silanol groups of mica and the hydroxyl groups of PVA and carbonyl groups of PMMA.

Epitaxial LaNiO₃ (LNO) thin films prepared from the sols modified with polyethyleneimine (PEI) were grown on single-crystal LaAlO₃, (LaAlO₃)_0.3(SrAlTaO₆)_0.7, and SrTiO₃ substrates, respectively, using a simple polymer assisted deposition (PAD). The epitaxial structure, surface morphologies and transport of the LNO films were studied by X-ray diffraction (θ/2θ symmetric scan, ω-scan, and in-plane φ-scan), the field emission scanning electron microscopy, and a standard dc four-probe method. It is found that, compared with that of LNO bulk, the c-axis parameter of the LNO film increases under compressive strain and decreases under tensile strain. All the LNO films exhibit metal properties in the temperature-dependent resistivity. The resistivity of the LNO films shows an increasing trend with the lattice mismatch strain changing from compressive to tensile. It is suggested that the oxygen vacancy compensated by more Ni²⁺ changed from Ni³⁺ in the film increases with the strain changing from compressive to tensile, which results in the increase of the resistivity.

It is interesting to explore a novel oxyfluoride glass with good glass stability to be applied in optical communication and optical windows at infrared (IR) wavelength. We demonstrated a new glass of Ga₂O₃-doped ZrF₄−BaF₂−LaF₃−AlF₃−NaF (ZBLAN) glass using a melt-quenched technique. The effect of Ga₂O₃-doping on glass properties and structure was characterized by differential thermal analysis (DTA), IR spectra, Raman spectra, and X-ray diffraction (XRD). It is found that the glass thermal stability (ΔT) increases by 14% when the addition of Ga₂O₃ reaches 1mol%. With the increase of Ga₂O₃ content, the density and refractive index of the glasses increase. Ga₂O₃-doping does not affect the IR cut-off edge and maintains the transmittance near 90% in the range of 2.5–5 µm, which is almost equal to the undoped sample. Ga₂O₃-doping hardly changes the initial coordinated structure of Zr⁴⁺ according to the results of IR spectra and Raman spectra. Ga³⁺ holds in the interstice site of the network coordinated with F⁻ and the part of O²⁻ introduced by Ga₂O₃ is coordinated with Al³⁺ forming Al−O bond. This study offers a new glass composition that may be potentially used in fabricating mid-IR optical fiber and large-size glasses for IR windows.

The wear behavior of titanium silicon carbide MAX phase was investigated. Samples of highly pure Ti₃SiC₂ and containing 8% of TiC, sliding dryly against Corundum counterpart, were tested at various speeds increasing from 5 to 60 m/s and under applied pressure of 0.1–0.8 MPa. The sliding-wear tests were performed on Tribometer, at room temperature of 15 °C with a relative humidity of 10%. The expermental results show that the presence of TiC particles can be beneficial to reducing the wear rate for certain ranges of sliding speed and applied pressure. The sliding-wear performances were expressed as a mathematical model, obtained through a modelling by the method of design of experiment. The influence of TiC impurities on the wear behaviors was also investigated. It is concluded that the wear mechanisms of samples are more affected by the presence of TiC under the effect of applied pressure compared with that of the sliding speed.

Hydrothermal (HT) ZnO substrates were usually used as seeds for the vapor growth of ZnO crystals. In this work, ZnO bulk crystals were grown using the relatively low-cost GaN/Al₂O₃ substrates as seeds by chemical vapor transport (CVT). With the increase of growth time, the dislocation densities in the crystal decreased from about 1×10⁶ to 6×10³ cm⁻². The carrier concentration decreased from 1.24×10¹⁹ to 1.57×10¹⁷ cm⁻³, while the carrier mobility increased from 63.8 to 179 cm²/(V·s). The optical transmittance in the VISNIR wavelength increased significantly in combination with the decreasing dislocation densities and impurity concentrations. The dislocation lines and related fast diffusion paths gradually decreased and disappeared in the late growth stage, and the crystal qualities were consequently improved. The experimental results show that the properties of as-grown ZnO crystals are comparable with bulk ZnO grown on the HT substrates to some extent. The GaN/Al₂O₃ seeds may have a potential application value in the industrial production of ZnO single crystals.

Nd³⁺, Er³⁺ ions doped 0.9(Ge_0.25Ga_0.10S_0.65)-0.1CsBr chalcohalide glass were prepared via melt-quenching method, and heat treated at 360 °C in high purity Ar gas atmosphere for different hours for the early stage of crystallization. The effect of heat treatment durations on visible upconversion luminescence and near infrared emission from Nd³⁺ ions and Er³⁺ ions were investigated. The specimens kept amorphous status until the heat treatment duration extended to 10 hours, for Ga₂S₃ nano-crystal formation in glass matrix. The stark splitting in visible upconversion luminescence center at 600 nm from Nd³⁺ ions weakened, and disappeared, and the shape of infrared emission centered at 1 550 nm from Er³⁺ ions changed, with the heat treatment duration increased. The lifetime of Nd³⁺: ⁴F_3/2 level and Er³ ₊: ⁴I_13/2 level dropped, then increased with heat treatment duration increased. X-ray diffraction patterns and transmission electron microscope images confirmed the amorphous state and Ga₂S₃ nano-crystals formation in glass matrix. The rare earth ions local environment changes with heat treatment duration were proposed, based on the emission and lifetime changes. This research will be helpful for the understanding of rare earth doped chalcohalide crystallization mechanism and processes.

Ho doping 0.825K_0.5Na_0.5NbO₃-0.175Sr(Yb_0.5Nb_0.5)O₃ (KNN-SYbN-x%Ho) transparent ceramics were prepared by solid-state sintering method. The structure, ferroelectric, energy storage, and optical properties of KNN-SYbN-x%Ho were explored. With the addition of Ho, under the excitation of a 980 nm laser, the ceramics exhibit up-conversion luminescence properties with wavelengths of 550 nm and 670 nm, however, the ceramics change from pseudo-cubic phase to triphase-orthorhombic phase and the light transmittance decreases. The addition of Ho significantly enhances the ferroelectric properties and the energy storage performance of KNN-SYbN-x%Ho ceramics. When x=0.15, the residual polarization P _r = 9.11 μC/cm², while x=0.20, the maximum energy storage density W _rec reaches 0.26 J/cm³, and the energy storage efficiency η reaches 87.1%.

Using CaCO₃, Sc₂O₃, and CeO₂ as raw materials, we prepared the CaSc₂O₄:Ce³⁺ green phosphors for white light LEDs via a high-temperature solid-phase method in a reducing atmosphere. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), fluorescence spectroscopy and other means were used to characterize the phase structure, apparent morphology, and photoluminescence properties of the product. CaSc₂O₄ was synthesized under a reducing atmosphere (95% N₂+5% H₂) at 1 400 °C for 4 hours. Upon excitation with a blue light (450 nm wavelength), CaSc₂O₄:Ce³⁺ displays a broadband green emission peak at 525 nm. The color coordinates of CaSc₂O₄:7% Ce³⁺ emission peak are (0.3712, 0.5940), and the product morphology is 1 μm granular. Hence, it acts as a green phosphor suitable for white LEDs that can be excited by blue light.

The crystal structure and morphology of the mineralization products were studied by scanning electron microscopy (SEM) and X-ray diffraction (XRD), and the thermal properties were studied by thermogravimetric-differential scanning calorimetry (DSC) analysis. The changes of microorganism quantity and enzyme activity in pore solution with time were measured. The experimental results show that microorganism quantity and enzyme activity in pore solution reach the maximum at 50–60 h, mineralization curing begins at this time, the strength of microbial mineralized steel slag reaches the maximum. This study provides a good selection basis for selecting the optimum mineralization system for the production of microbial mineralized steel slag products. Bacterial mineralization can accelerate the rate of carbon sequestration in the mineralization process. The compressive strength of steel slag with 1.5% bacterial can reach up to 55.6 MPa. The microstructure and thermal properties of calcium carbonate precipitate induced by the enzymes of bacillus subtilis differs from the chemical precipitation in pore solution of steel slag. Through the analysis of the mineralized products of steel slag, the reaction rate of free calcium oxide and free magnesium oxide in steel slag after the addition of microorganisms is significantly increased, which improves the stability of steel slag as cementitious material. Meanwhile, the production of calcium carbonate, the main mineralized product, is significantly increased.

A theory of superconductivity based on Bose-Einstein statistics was proposed, which can lead to a formula for T _C (critical temperature) similar to that of BCS theory, and provide a possible explanation for the complexity of isotope effect and the normal state energy gap in copper-oxides. We proceeded from a 3-dimensional harmonic oscillator model to equivalent the superconducting state to a two-dimensional Bose-Einstein condensate bound longitudinally, and pointed out the application conditions of the theory. Under this scheme, we analyzed some typical structural features in copper oxides that favor the production of high-temperature superconductivity. We also discovered that combining this theory with an alternative mechanism -strong coupling to local spin configurations-provided some useful hints for exploring new superconducting materials. In addition, we pointed out a possible link between the phenomenon of superconductivity and magnetostriction, then we proposed some combinations of elements as possible candidates for high temperature superconducting materials based on those analysis.

Owing to porous structure, stable chemical properties, low cost and available raw material, biomass carbon aerogel is a promising adsorbent framework material. Herein, a pomelo peel-based carbon aerogel was prepared by hydrothermal-freeze drying-high temperature carbonization method and modified with Tri-n-ocylamine (N235) and γ-Glycidyloxypropyltrimethoxysilane (KH560) via impregnation process. The as-prepared adsorbents exhibit superior adsorption performance for iodide in simulated and oilfield brines, and the highest adsorption amount of iodide in oilfield brine can reach 0.58 mmol/g. It is also demonstrated by adsorption kinetics and isotherms that iodide is adsorbed through chemical adsorption. Protonation of tertiary amide group in N235 and epoxy group in KH560 may be the main reason for the highly selective adsorption of iodide.

In the cemented paste backfill (CPB) method, which can also be used for fortification purposes in mines, different additive materials with pozzolanic properties can be employed as substitutes instead of cement that is the main binder. One of the most popular pozzolanic materials that can be employed instead of cement is fly ash, which is thermal power plant tailings. But the compositions of fly ash and tailings used in high amounts in the CPB method, as well as the chemical structures that these materials form by interacting with the cement binder, affect the mechanical properties of the material depending on time. In this study, fly ash with 4 different chemical compositions (TFA, SFA, YFA, and CFA) was used as a cement substitute in CPB. By substituting fly ash with different chemical compositions in different proportions, CPB samples were created and their strength was elucidated according to 28, 56, and 90-day curing times. The results of the study revealed that TFA with the highest CaO/SiO₂ and SO₃ ratios remained stable at the strength values of 6 MPa (total 9% binder) and 10 MPa (total 11% binder) in the long term. However, CFA with the lowest CaO/SiO₂, SO₃, and the highest SiO₂+Al₂O₃+Fe₂O₃ ratios resulted in the greatest strength increase at a 20% substitution rate (11% of the total binder). Nevertheless, it was found that the SFA, which is in Class F, increased its strength in the early period based on the CaO rate.

C30 coral aggregate concrete with chlorella control effect was prepared by adding nano-TiO₂ and hydrophobic material, and the effects of nano-TiO₂ and hydrophobic material on the basic properties of C30 coral aggregate concrete and chlorella control effect under different experimental conditions were compared. The experimental results show that nano-TiO₂ and hydrophobic materials have a certain degree of influence on the basic properties of concrete, but the influence is not significant. Under long-term immersion, nano-TiO₂ and hydrophobic materials can inhibit the growth of Chlorella vulgaris. The maximum fluorescence value of concrete is decreased by 53.6% after adding TiO₂, and the maximum fluorescence value of concrete is prolonged by 20% (1 day). The maximum fluorescence value of concrete is decreased by 67.7% after adding hydrophobic materials, and the maximum fluorescence value of concrete is also prolonged by 20% (1 day); Under the condition of simulated tidal water, the inhibition effect of Nano-TiO₂ on the growth degree and growth rate of Chlorella vulgaris is weakened, at this time the maximum fluorescence value of concrete mixed with nano-TiO₂ is decreased by 50.5%, and the maximum fluorescence value is only prolonged by 14.3%; while the inhibition of hydrophobic materials on the growth degree and growth rate of Chlorella vulgaris is enhanced significantly, and the maximum fluorescence value of concrete with hydrophobic materials is decreased by 80.3%; the maximum fluorescence time is prolonged by 114.3%.

A new and more ecologically sound cementing material known as “bio-cement” has been found to have the capacity to consolidate loose gravel into sand columns offering a certain degree of strength, and to fill and repair cracks in concrete to restore resilience. The typical representative is the microbial induced calcium carbonate deposition technology(MICP) and enzyme induced calcite precipitation (EICP). As part of this research, EICP with soybean urease as the core was studied. The test results show that soybean urease activity is significantly affected by pH and urea concentration values, while the external nickel source is not found to impair a stimulating effect on activity. When the concrete specimens were immersed in the composite solution of soybean urease, urea, and calcium chloride after having been subjected to a high temperature, a continuous layer of white precipitations quickly appeared on the surface of the specimens. Measured using a metalloscope, the thickness of the precipitations was found to reach up to 2.0 mm, while the surface water absorption rate was reduced by 70%. The effects of this combined outcome are believed to significantly protect and improve the durability of the concrete specimens previously subjected to a high temperature. At the same time, the composite solution is shown to be capable of cementing fly ash, with the cubic strength of the finished samples reaching 4.0 MPa after 3 days. Results from the use of a scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction(XRD), reveal that both the white precipitations on the surface of the concrete specimens and the cement binding the fly ash particles are calcite crystals. It is concluded from these preliminary study results that the use of soybean urease as a bio-cement had proved successful.

The resin-sand mixture was proposed to be used as the surface course, and cement permeable concrete was used as the base course; such two kinds of materials were combined to prepare water-permeable brick with a composite structure. The compressive strength, flexural strength, and permeability were studied by using adjusting the contents of carbon fiber, quartz powder, cement, sand, and surfactant. The study shows that the hydrophilicity of the resin-sand mixture can be improved after any amount of resin is replaced by quartz powder; by using the surfactant, the interface energy of the particles can be reduced so that the water permeability of the surface course can be promoted effectively. However, the mechanical properties of the surface course were negatively affected by the surfactant. With the optimal process consideration in the experiments, the properties about compressive strength, flexural strength, and permeability of the composite permeable brick can meet the requirements of the specifications of resin-sand based water permeable brick JGT 376–2012 (compressive strength was higher than 35 MPa, the flexural strength exceeded 5.19 MPa, and the average permeability coefficient was higher than 2.3×10⁻² cm/s). There are no obvious pores on the surface course and only water molecules can pass through it, therefore, the surface of the permeable brick cannot be blocked up by solid substances, and the permeability of such permeable brick can be improved effectively in this way.

According to the morphological characteristics of crushed stone, the sphericity was introduced to establish the theoretical calculation model of volume fraction of interfacial transition zone (ITZ) around crushed stone. The sphericity of crushed stone was obtained by image processing technology and numerical statistics. The experimental results show that when the maximum particle size of coarse aggregate is less than 31.5 mm, the practical sphericity is generally around 0.75, while the sphericity of sand is generally above 0.85. And the closer to 1 the practical sphericity is, the smaller the ITZ volume fraction (V _ITZ) is, that is, the closer to spherical shape the aggregate is, the lower the ITZ content in concrete is. The V _ITZ and ITZ thickness in concrete and mortar have a linear relationship, and the ITZ content in concrete is lower than that in mortar at the same aggregate volume fraction.

Considering the economic and environmental benefits associated with the recycling of polyester (PET) fibres, it is vital to study the application of fibre-reinforced cement composites. According to the characteristics of the wind-blown sand environment in Inner Mongolia, the erosion resistance of the polyester fibre-reinforced cement composites (PETFRCC) with different PET fibre contents to various erosion angles, velocities and sand particle flows was investigated by the gas-blast method. Based on the actual conditions of sandstorms in Inner Mongolia, the sand erosion parameters required for testing were calculated by the similarity theory. The elastic-plastic model and rigid plastic model of PETFRCC and cement mortar were established, and the energy consumption mechanism of the model under particle impact was analyzed. The experimental results indicate that the microstructure of PETFRCC rafter hydration causes a spring-like buffering effect, and the deformation of PETFRCC under the same impact load is slightly smaller than that of cement mortar, and the damage mechanism of PETFRCC is mainly characterized by fiber deformation and slight brittle spalling of matrix. And under the most unfavorable conditions of the erosion, the erosion rate of 0.5PETFRCC is about 57.69% lower than that of cement mortar, showing better erosion resistance.

In order to predict the corrosion trendency of X100 pipeline steel in flowing oilfield produced water, the effect of flow rate on the corrosion behavior of X100 pipeline steel was studied under general dynamic condition and simulated real working condition at the flow rate of 0.2, 0.4, and 0.6 m·s⁻¹. Potentiodynamic polarization curves and electrochemical impedance spectroscopy were used to study the corrosion behavior of X100 steel. Energy dispersive spectroscopy, X-ray diffraction and scanning electron microscopy were used to analyze corrosion product composition and micromorphology. The experimental results show that the corrosion is more serious under simulated real working conditions than that under the general dynamic conditions. In any case the corrosion current density increases with the increase of the flow rate, and the total impedance value decreases. The corrosion products include Fe₃O₄, Fe₂O₃, and FeOOH. The mass transfer and electrochemistry were simulated by flow coupled in COMSOL software. The multiphysical field coupling simulation results are closer to the engineering practice than the single flow field simulation, and similar results from the experiments were obtained. Both experimental and simulation results reveal that the higher flow rate is, the more serious corrosion appear and the more corrosion products accumulate. By combining experimental and COMSOL simulation data, the corrosion process model of X100 steel was proposed.

The orientation relationships, carbon partitioning and strengthening mechanism of a novel ultrahigh strength steel were analyzed in depth during the complex process of heat treatment. The experimental results reveal that the (011)α//()γ, [100]α//[011]γ orientation relationships can be drawn between martensite and retained austenite. The position and angle of martensite and retained austenite are shown more clearly from the stereographic projections. Moreover, the calculated results show that the carbon content near the austenite interface is the highest in the shorter carbon allocation time. With the further increase of time, its carbon content gradually decreases. Furthermore, a model of the relationship between yield strength and strengthening mechanism was established. It was proved that the main strengthening components contributing to the yield strength include Orowan strengthening, grain-size strengthening and dislocation hardening. The main strengthening mechanism of steel in this experiment is dislocation strengthening.

In order to solve the problem that the vulcanizing agent utilization rate is low and the dilution effect of copper slag is poor, the vortex stirring dilution method was used to improve the conditions of the dilution kinetics and copper recovery. The water model was used to simulate the effect of copper slag dilution. Under the premise of keeping the Reynolds number consistent, silicone oil and glass beads were used instead of copper slag and vulcanizing agent. Based on the relationship between voltage and concentration, the PC6D dual-channel particle concentration measuring instrument was used to study the stirring speed and the insertion depth of the stirring paddle in model experiments, and the suitable conditions were speed 250 rpm and insertion depth 70 mm. The fire dilution of copper slag was done under the conditions. After stirring and sedimentation, the Fe₃O₄ in slag decreased from 22.58% to 4.65%, and the copper content of the slag decreased from 2.94% to 0.34%. The copper recovery was 88.44%.

The solidification and corrosion behavior of the Ti/B added Zn-Al-Mg alloys were experimentally investigated by means of microstructure characterization and electrochemical test. The basic calculations were carried out to predict the characteristics of the Ti-added Zn-Al-Mg alloys. The Zn-Al-Mg ingots with minor doping of Ti/B were prepared and solidified under different cooling rate, including air cooling, water quenching and furnace cooling. The scanning electron microscopy (SEM) and the X-ray diffraction method (XRD) were used to determine the microstructures and phase types of the alloy samples. It could be discovered that trace TiAl₃ particles were dispersed in the Ti/B added alloy samples which provide the heterogeneous nucleation sites to refine the size of the dendrites and the eutectic microstructures. More fined microstructures with the addition of both Ti and B were obtained compared with those with the merely addition of Ti, and the water cooled alloys presented the finest microstructures due to the fastest cooling rate. It could also be noticed that with the increasing solidification rate, the percentage of the MgZn₂ phase turned out to be higher because of the Mg₂Zn₁₁↔MgZn₂ transition, which is in consistent with the results in the actual hot-dip galvanizing process. Electrochemical experiments in the previous work included methods the of the Tafel polarization test and the electrochemical impedance spectroscopy test (EIS). Results show that the quenched Zn-Al-Mg alloy with the addition of both Ti and B takes on best corrosion resistance. Consequently, the addition of certain amount of Ti/B elements and the appropriate elevation of the cooling rate will be the practicable approaches to optimize the microstructure and the corrosion resistance of the Zn-Al-Mg coatings in the actual galvanizing process.

To elucidate the diffusion behavior of carbon atoms within the austenite region, the decarbonization of 72LX steel bloom was investigated. Experimental studies were performed to obtain the depth profiles of the decarburized layers within the temperature range of 950–1 250 °C. The findings show that, within a temperature range of 950–1 200 °C, both the depth of the decarburization layer of the grain interior (h _in) and the depth of the decarbonization effect zone of the grain boundary (h _b) increase concurrently with increasing holding temperatures and times and an inflection point is observed at 1 200 °C. By measuring the change in the sample diameter before and after the experiment, the change in the radius reduction of h _Fe causes by oxidation is obtained. Minimal changes are observed in h _Fe when the temperature is below 1 050 °C. As the temperature increases to 1 100 °C, a sudden change in h _Fe is observed, which corresponds to a rapid increase in oxidation. At temperatures above 1 100 °C, a more gradual change is observed. From the experimental results, a two-dimensional decarburization mathematical model is established and the carbon diffusion coefficients at different temperatures are obtained by simulation and regression fitting. The simulation values obtain from the carbon diffusion model matched well with the experimental values, thereby confirming the accuracy of the simulation process.

High-temperature tensile tests were conducted for high corrosion resistant weathering steel S450EW. The morphologies of fracture microstructures, dislocations and precipitates were investigated by field emission scanning electron microscopy and transmission electron microscopy. The high-temperature plastic deformation behavior and brittle mechanism of S450EW steel were also studied. The experimental results show that the ductility troughs appear at 700–850°C and 650–900°C when the strain rates are 3×10⁻³ and 1.5×10⁻² s⁻¹, respectively. With the increase of strain rates, the ductility trough moves to the lower temperature side. The hot ductility is best when the cooling rate is 5 °C/s before deformation at 750 °C and the area reduction rate reaches 60.56%. Fine second phase particles and inclusions precipitated before and during deformation provide effective core positions for microcracks or microvoids formation during deformation process. It is also easy to cause stress concentration which results in microcracks or microvoids between grains during deformation and ultimately causes damage along the grain boundaries. The precipitated particles inhibit austenite dynamic recrystallization and therefore enhance intergranular fracture along austenite grain boundaries. The deformation induced proeutectoid ferrite films distribute along the austenite grain boundaries hinder the dynamic recrystallization. The deformation concentrated on network ferrite films produces damage of grain boundaries.

The dissolution behavior of delta ferrites in martensitic heat-resistant steel was studied. And the reason why the dissolution rate of delta ferrites decreased with dissolution time was discussed. The experimental results show that the chemical compositions of delta ferrites negligibly change with dissolution time. The decrease of dissolution rate of delta ferrites with dissolution time should be attributed to the change of shape and distribution of delta ferrites. The shape of delta ferrites tends to transfer from polygon to sphere with dissolution time, causing the decrease of specific surface area of delta ferrites. The distribution position of delta ferrites tends to transfer from boundaries of austenite grains to interior of austenite grains with dissolution time, decreasing the diffusion coefficient of alloy atoms. Both them decrease the dissolution rate of delta ferrites.

To understand the solidification pathway and microstructure evolution of Mg-9Al-2Ca alloy, the cooling curve of the alloy solidified under furnace cooling was measured and the water-quenched samples were observed. The experimental results show that the matrix phase of α-Mg dendrites is first generated at 596 °C during the solidification process, then the eutectic phases of Al₂Ca and Mg₁₇Al₁₂ are formed at 518 and 447 °C, respectively, and the solidification is terminated at 436 °C. In the process of solidification, the seaweed dendrites of α-Mg get coarser and are gradually transformed into the global dendrites; besides, the secondary dendrite arms spacing (SDAS) of α-Mg as well as the solid fraction are both increased, while the increasing rate of SDAS of α-Mg and the solid fraction in the temperature region of 600–550 °C is faster than that in the temperature region of 550–436 °C. And a power function relationship can be used to illustrate the change of the SDAS and the solid fraction with the temperature of solidification.

The influence of the electromagnetic energy on the microstructure of Al−5Ti−B grain refiner was discussed. In this study, the electromagnetic energy was applied above the liquid phase line temperature. Compared with Al−5Ti−B without electromagnetic energy applied, the experimental results show that the size of secondary particles is reduced and its size distribution becomes more uniform. Simultaneously, the secondary phase particles are uniformly spread in the matrix response to the electromagnetic energy. Moreover, when adding Al−5Ti−B with electromagnetic energy to the pure aluminum melt, it is clear that the electromagnetic energy has a significantly impact on refining properties of Al−5Ti−B. The mean size of pure aluminum is reduced by 27.6% in maximum with more uniform size distribution. The change in the microstructure is attributed to the electromagnetic energy changes the melt structure. With the electromagnetic energy entry into the system, the electromagnetic energy reduces the size of atomic clusters and increases the number of atomic clusters, thus the number of nuclei increases.

Natural rubber/styrene-butadiene-styrene (NR/SBS) membrane was prepared by solution blend, and then used for recovery of butanol from its dilute solution by pervaporation (PV). The thermodynamic and mechanical properties of NR/SBS blend membrane were characterized by TGA and tensile test, respectively. A layer of relatively dense blend membrane with the thickness of about 37 µm was closely cast on a layer of porous polyvinylidene difluoride (PVDF) support. And there was no obvious phase separation observed between the interface of two layers. Both flux and separation factor increased with increasing feed temperature. Butanol flux increased as feed concentration increased consistently. The blend membrane which got the best performance obtained membrane separation factor of 28.8 with total flux of 2695.2 g/m²h at 70 °C when feed concentration was 4.00wt%.

A series of degradable polyesters was synthesized via melt polymerization of 3,6-dioxaoctane-1,8-dioic acid and five different diols, catalyzed by antimony trioxide (Sb₂O₃). The polymers were characterized by FT-IR and ¹H NMR spectroscopy, gel permeation chromatography (GPC) and differential scanning calorimetry (DSC) analysis. The polydispersity index (PDI = M _w/M _n) of the polyesters ranged from 1.55 to 1.99, the weight-average molecular weight (M _w) from 1.8 × 10⁴ to 3.2 × 10⁴ Da, the melting point from 63 to 123 °C, and the highest decomposition temperature observed was 363 °C. The influence of the structure of the polymer chain on hydrolytic degradability was investigated with tests performed at three different values of pH. The findings obtained provide useful insight for the molecular design and the synthesis of degradable polyesters.

Poly(nickel 1,1,2,2-ethenetetrathiolate) (poly[Na _x(Ni-ett)]) is one of the most promising n-type organic thermoelectric materials which can be used in wearable devices. However, the conventional solution method is time-consuming and the prepared poly[Na _x(Ni-ett)] usually has poor crystallinity, which does not benefit for achieving high thermoelectric performance. Here, a new one-step solvothermal method under the high reaction temperature and high vapor pressure was developed to prepare poly[Na _x(Ni-ett)] with a quite short period. The experimental results show crystallinity and electrical conductivity are greatly enhanced as compared with those prepared by conventional solution method. As a result, a maximum ZT value of 0.04 was achieved at 440 K, which is about four times of the polymer prepared by the conventional solution method. This study may provide a new route to enhance the TE properties of n-type organic thermoelectric materials.

The bio-based epoxy nanocomposite (GAER/DOPO-POSS) was prepared from gallic epoxy resin (GAER) and polyhedral oligomeric silsesquioxane (which containing 9,10-dihydrogen-9-oxo-10-phosphorus-phenanthrene-10-oxide groups, called DOPO-POSS). The polyhedral oligomeric silsesquioxane containing epoxy groups (E-POSS) was grafted onto aminated graphene oxide (E-GO), then the novel POSS-E-GO was obtained. The POSS-E-GO was used as modifier for GAER/DOPO-POSS nanocomposite. The influences of POSS-E-GO content on mechanical properties, dynamic mechanical properties and thermal stability of GAER/DOPO-POSS nanocomposites were determined. The experimental results show that POSS-E-GO can significantly improve the toughness of the GAER/DOPO-POSS nanocomposite. When 0.5wt% POSS-E-GO was added in GAER/DOPO-POSS nanocomposite, the impact strength of the nanocomposite was 4.74 kJ/m² higher than that in the absence of POSS-E-GO, meantime the initial thermal degradation temperature was 277 °C.

The synthesis of mesoporous β-tricalcium phosphate (β-TCP) powder was performed by using the microemulsion approach, with hexadecyltrimethyl ammonium bromide (CTAB)/cyclohexane/n-octyl alcohol microemulsion system. The influences of different pH values and calcination temperatures on the phase composition of the β-TCP powder were studied. The in vitro proliferation of bone marrow mesenchymal stem cells (BMSCs) in the suspensions of β-TCP powders with meso-structure was studied. The phase composition, mesoporous structure, powder morphology, cell morphology and the optical density (OD) were characterized through X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Fourier transform infrared (FTIR) spectroscopy, N₂ adsorption-desorption isotherms, inverted phase contrast microscopy and Multiskan spectrum, respectively. The mesoporous β-TCP powder with specific surface area of 12.85 m²/g and the average pore size 7.11 nm was obtained through the microemulsion approach (100 g/L CTAB/250 mL/L cyclohexane/250 mL/L n-octyl alcohol) with a controlled pH of 7.0, after calcinating the powder at 800 °C. It was confirmed that mesoporous β-TCP powder benefits the activity of BMSCs more than the non-mesoporous β-TCP powder.