The novel visible light-induced carbon nitride (g-C₃N₄) and BiVO₄ composite photocatalysts were obtained through a simple mixing-calcination method. The physical and photophysical properties of the BiVO₄-g-C₃N₄ composites were investigated by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, UV-vis diffuse reflection spectroscopy, high-resolution transmission electron microscopy (HRTEM), photoluminescent (PL) spectroscopy, and BET surface area measurements. Photocatalytic oxidation ability of the prepared samples was examined by studying the degradation of rhodamine B (RhB) as a target pollutant under visible-light irradiation. The composite photocatalysts exhibited an enhanced photocatalytic performance in degrading RhB. The optimal g-C₃N₄ content of the composite photocatalysts was determined for the photodegradation activity. The improved photocatalytic activity of the as-prepared composite photocatalyst may be attributed to the enhancement of photo-generated electron-hole separation at the interface.

Phspho-olivine LiFePO₄ was synthesized from the relatively insoluble lithium source Li₂CO₃, proper iron and phosphorus sources (n(Li):n(Fe):n(P)=1:1:1) by a novel hydrothermal method. Afterwards, the optimal sample was mixed with glucose and two-step calcinated (500 °C and 750 °C) under high-purity N₂ to obtain the LiFePO₄/C composite. The resultant samples were characterized by X-ray diffraction (XRD), atomic absorption spectrometry (AAS), scanning electron microscops (SEM), transmission electron microscopy (TEM), energy dispersive spectrometry (EDS), elementary analysis (EA) and electrochemical tests. The results show that the optimal reaction condition is to set the reactant concentration at 0.5 mol·L⁻¹, the reaction temperature at 180 °C for 16 h duration. During the reaction course, an intermediate product NH₄FePO₄·H₂O was first synthesized, and then it reacted with Li⁺ to form LiFePO₄. The optimized LiFePO₄ sample with an average particle size (300 to 500 nm) and regular morphology exhibits a relatively high discharge capacity of 84.95 mAh· g⁻¹ at the first charge-discharge cycle (0.1C, 1C=170 mA·g⁻¹). Moreover, the prepared LiFePO₄/C composite shows a high discharge capacity of 154.3 mAh·g⁻¹ at 0.1C and 128.2 mAh·g⁻¹ even at 5C. Besides it has good reversibility and stability in CV test.

Tungsten carbide (WC) nanoparticles were fabricated from a novel refluxing-derived precursor. The precursor was prepared by acid hydrolysis of Na₂WO₄ with concentrated HCl in water followed by refluxing with ethanol and n-Dedocane, respectively. Then it was heat-treated to 1 200 °C for 2 h in vacuum to obtain WC nanoparticles. X-ray studies reveal the formation of hexagonal tungsten carbide and the grain size of 24.3 nm. SEM image shows WC nanoparticles with particle size of 20–60 nm. Long time refluxing results in alkane dehydrogenation and coke formation. The coke is the carbon source in the carbothermal reduction reaction. The novel route of two-stage refluxing is quite general and can be applied in the synthesis of similar carbides.

Zn₂SiO₄: Tb³⁺, Zn₂SiO₄: Ce³⁺, Zn₂SiO₄: Tb³⁺, Ce³⁺ phosphors were prepared by solidstate reaction at 1 150 °C for 2 h under a weak reducing atmosphere. Moreover, the XRD patterns and photoluminescence spectra were recorded and the effects of Tb³⁺ and Ce³⁺ concentration on the luminescent properties of as-synthesized phosphors were investigated. The emission spectra under ultraviolet light (333 nm) radiation showed a dominant peak at 542 nm attributed to the ⁵D₄→⁷F₅ transition of Tb³⁺, which was enhanced significantly (about 45 times) by the co-doping of Ce³⁺, indicating that there occurred an efficient energy transfer from Ce³⁺ to Tb³⁺. According to the Dexter’s energy transfer formula of multipolar interaction, it was demonstrated that the energy transfer between Ce³⁺ and Tb³⁺ was due to the electric dipolar-dipolar interaction of the resonance transfer.

Ba_0.65Sr_0.35TiO₃ (BST) nanocrystals doped with different concentrations of Er³⁺ ion were fabricated using sol-gel method. The structure and morphology of these BST nanocrystals were studied using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The X-ray diffraction patterns of all the nanocrystals prepared in the study correspond to polycrystalline perovskite BST structure. The blue and green upconversion luminescence properties of Er³⁺ doped BST nanocrystals were investigated under excitation by a 785-nm laser. The upconversion emission bands centered at 407, 523, and 547 nm can be attributed to ²H_9/2, ⁴I_15/2, ²H_11/2, ⁴I_15/2, and ⁴S_3/2, ⁴I_15/2 transitions of Er³⁺ ion, respectively. The upconversion mechanism was studied in detail, based on the laser power dependence of the upconverted emissions. In addition, we examined the dependence of the intensity of green upconverted luminescence on the doping concentration of Er³⁺ ions, and discussed the mechanism underlying the process.

TiO₂ thin films were fabricated by RF magnetron sputtering on titanium substrates and then implanted with different amounts of carbon. The microstructure, valence states and optical characteristics of each sample were investigated by X-ray diffraction, X-ray photoelectron spectroscopy and UV-vis diffuse reflection spectroscopy. Photoelectric property was evaluated under visible light using a xenon lamp as illuminant. The experimental results indicate that the implanting carbon concentration has a significant influence on film’s micro structure and element valence states. The dominant valence states of carbon vary as carbon content increases. Carbon ion implantation remarkably enhances the current density and photocatalytic capability of TiO₂ thin films. The optimized implanting content is 9.83×10¹⁷ ion/cm², which gives rise to a 150% increased photocurrent and degradation rate.

The properties of the carbonated brick made of steel slag-slaked lime mixture such as strength, drying shrinkage, water absorption and soundness were mainly investigated. The experimental results indicate that, after carbonation, the strength of the brick increases, its drying shrinkage reduces, and its soundness becomes eligible. The optimal slaked lime/steel slag (SL/SS) ratio for the carbonated brick is 0.2 and the as-prepared brick meets the requirements of the Chinese standard for MU20-grade building bricks, additionally, it also demonstrates prominent environmental benefits. The XRD and pore structure analyses indicate that the excellent properties of this carbonated brick are attributed to the formation of carbonate crystals and the dense structure due to the carbonation.

Strain-rate sensitivities of 55vol%–65vol% aluminum 2024-T6/TiB₂ composites and the corresponding aluminum 2024-T6 matrix were investigated using split Hopkinson pressure bar method. The experimental results showed that 55vol%–65vol% aluminum 2024-T6/TiB₂ composites exhibited significant strain-rate sensitivities, which were three times higher than the strain-rate sensitivity of the aluminum 2024-T6 matrix. The strain-rate sensitivity of the aluminum 2024-T6 matrix composites rose obviously with increasing reinforcement content (up to 60%), which agreed with that from the previous researches. But it decreased as the ceramic reinforcement content reached 65%. After high strain rates compression, a large number of dislocations and micro-cracks were found inside the matrix and the TiB₂ particles, respectively. These micro-cracks can accelerate the brittle fracture of the composites. The aluminum 2024-T6/TiB₂ composites showed various fracture characteristics and shear instability was the predominant failure mechanism under dynamic loading.

Mesoporous silica-zirconia supported phosphotungstic acid was synthesized by evaporation induced self-assembly method and used as oxidative desulfurization catalysts. The structural properties of as-prepared catalysts were characterized using various analytical techniques including X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, and nitrogen adsorption desorption. The experimental results showed that HPW was highly dispersed on mesoporous framework. The surface acidity of catalysts was analyzed by FTIR measurement of adsorbed pyridine.The surface Lewis acidity was improved with increasing the content of zirconium in the samples. The mesoporous composites were used as catalysts with H₂O₂ as oxidant for oxidative desulfurization of model fuel. The catalytic activity results showed that the surface Lewis acid sites acted as selective adsorption active sites for dibenzothiophene, which facilitated the sulfur removal from model fuel in the presence of arene. A slight decrease in activity of the recovered catalyst used in the proceeding rounds indicated the reusability of the catalyst.

Through the experiments and the numerical simulation of temperature field in multi-heat-source synthesis SiC furnace, in order to research the feature point in multi-heat-source synthesis furnace, the variation law of heat flux was studied and the multi-directional energy flow diffusion mechanism was revealed. The results show that, due to the shielding action between the heat-source and the superposition effect of thermal fields, the insulating effect is best in multi-heat-source synthesis furnace. The heat emission effect is good outside the common area between heat-sources, but the heat storage is poor. Compared with the synthesis furnace that heat source is parallelly arranged, the furnace of stereoscopic arrangement has a more obvious heat stacking effect and better heat preservation effect, but the air permeability of heat source connecting regions is worse. In the case with the same ingredients, the resistance to thermal diffusion and mass diffusion is higher in heat source connecting regions.

We put forward a new and ingenious method for the preparation of a new adsorbent by soaking, carbonizing and activating the mixture of hygroscopic salt and biomass material. The new adsorbent has high porosity, uniform distribution and high content of CaCl₂, and exhibits high adsorption performance. The ammonia uptake and specific cooling power (SCP) at 5 min adsorption time can reach as high as 0.19 g·g⁻¹ and 793.9 W·kg⁻¹, respectively. The concept of utilizing the biomass materials and hygroscopic salts as raw materials for the preparation of adsorbents is of practical interest with respect to the potential quantity of biomass materials around the world, indicating that there would be a new market for biomass materials.

SnS₂ nanoflakes were successfully synthesized via a simple hydrothermal process. The as-prepared SnS₂ samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen adsorption-desorption isotherms, and UV-vis diffuse reflectance spectroscopy (DRS). The photocatalytic activities of the as-prepared SnS₂ nanoflakes under visible light irradiation (λ>420 nm) were evaluated by the degradation of rhodamine B (RhB). The effect of hydrothermal temperatures on the photocatalytic efficiency of as-prepared SnS₂ nanoflakes was investigated. The experimental result showed that SnS₂ nanoflakes synthesized at the temprature of 160° had higher photocatalytic efficiency and good photocatalytic stability.

A new type of samarium ion activated luminescent glass ceramics with main crystal phase of melilite was prepared. The effect of heat-treatment temperature on the structure of glass ceramics was investigated by X-ray diffraction analysis (XRD), scanning electron microscope (SEM) and fluorescence spectrometer. In the Sm³⁺ doped SrO-MgO-SiO₂ glass ceramic, its excitation spectra are in the wavelength range of 350–500 nm, and its excitation peaks are at 360 nm, 374 nm, 404 nm, 417 nm, and 475 nm with the host excitation peak of 404 nm, showing a strong orange-red luminescence when using 404 nm violet to excite it, and its emission peaks are at 564 nm, 600 nm and 648 nm with the host emission peak at 600 nm. The increase in the heat-treatment temperature has no influence on the position of the fluorescent spectra. However, with the increase of heat-treatment temperature, the intensity of fluorescence spectrum shows an increasing tendency. The increase in the concentration of Sm³⁺ also improves the intensity of the fluorescent spectra. In the experimental concentration range (0.05mol%–0.30mol%), a special concentration quenching phenomenon happens.

SiC reinforced graphite composites were prepared via introducing carbide silicon into the natural graphite flakes (NGF) by hot-pressing process. Their physical and mechanical properties, including density, open porosity, flexural strength, and friction behavior were investigated. The addition of 30vol% SiC increased the bending strength of composites materials to 127 MPa, 2 times higher than 60 MPa of commercial pure graphite block. What was particularly interesting was that the as-obtained graphite composite with 30vol% SiC kept the same low friction coefficient of about 0.1 as pure graphite, and the wear resistance of composites increased.

An average failure index method based on accurate FEA was proposed for the tensile strength prediction of composite out-of-plane adhesive-bonded π joints. Based on the simple and independent maximum stress failure criterion, the failure index was introduced to characterize the degree of stress components close to their corresponding material strength. With a brief load transfer analysis, the weak fillers were prominent and further detailed discussion was performed. The maximum value among the average failure indices which were related with different stress components was filtrated to represent the failure strength of the critical surface, which is either the two curved upside surfaces or the bottom plane of the fillers for composite π joints. The tensile strength of three kinds of π joints with different material systems, configurations and lay-ups was predicted by the proposed method and corresponding experiments were conducted. Good agreements between the numerical and experimental results give evidence of the effectiveness of the proposed method. In contrast to the existed time-consuming strength prediction methods, the proposed method provides a capability of quickly assessing the failure of complex out-of-plane joints and is easy and convenient to be widely utilized in engineering.

Magnetically modified Fe-Al pillared bentonite (Fe₃O₄/Fe-Al-Bent) was prepared via chemical co-precipitation method and characterized by powder X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). A series of experiments were carried out to investigate the degradation of Orange II by the obtained heterogeneous catalysts in the presence of H₂O₂. The experimental result indicated that the synthetic materials had a high catalytic activity and good reusability.

CdS thin film was used as a suitable window layer for CdS/CdTe solar cell, and the properties of CdS thin films deposited by pulsed laser deposition (PLD), chemical bath deposition (CBD) and magnetron sputtering (MS) were reported. The experimental results show that the transmittances of PLD-CdS thin films are about 85% and the band gaps are about 2.38–2.42eV. SEM results show that the surface of PLD-CdS thin film is much more compact and uniform. PLD is more suitable to prepare the CdS thin films than CBD and MS. Based on the thorough study, by using totally PLD technique, the FTO/PLD-CdS(150 nm)/CSS-CdTe solar cell (0.0707 cm²) can be prepared with an efficiency of 10.475%.

Inorganic coating was fabricated on the surface of the porous Si₃N₄ ceramic by polymer derived (PD) and spraying technology, via using vinyl-polysilazane (PSN-1) as a preceramic polymer and Si₃N₄ and lithium aluminosilicate (LAS) powders as fillers. The phase and microstructure of the coatings were analyzed by X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM), respectively. The effect of the coatings on mechanical property and humidity resistance of the porous Si₃N₄ ceramic was investigated. The experimental results showed that we successfully fabricated the uniform and dense coating which preferably combined with the substrate upon the addition of fillers. The bending strength of the porous Si₃N₄ ceramic sprayed the coating increased by more than 18%, and the surface hardness increased by 1.7 times. The apparent porosity of the materials reduced by an average of 97.7%, and water absorption was below 0.5%. Therefore, the prepared coating with preferable density had an obviously moisture-proof and enhanced effect on the porous Si₃N₄ ceramic.

To acquire a well bonded interface between the copper and the diamond particles in diamond-copper matrix composites, an available process to apply a vapor deposited aluminum (Al) coating onto diamond particles was used to solve this interfacial problem. The diamond-copper matrix composites were prepared by spark plasma sintering (SPS) process and the effect of Al-coated diamond particles was demonstrated. The experimental results showed that the densification, interfacial bonding and thermal conductivity of Al-coated composites were evidently improved compared to those of the uncoated composites. A maximum thermal conductivity (TC) of 565 W/(m·K) was obtained in the coated composite containing 50vol% diamond particles sintered at 1 163 K. Additionally, the experimental data of thermal conductivity and coefficient of thermal expansion (CTE) were compared with the predictions from several theoretical models.

The high calcium type stone coal from Hubei province was leached by water and dilute acid separately after being roasted with different dosage of NaCl. The water leaching rate of vanadium (WLRV) was low and only 26.8% of vanadium can be leached by water when 4% NaCl was added, but the acid leaching rate of vanadium (ALRV) was relatively high. Calcium in the high calcium type stone coal is greatly superfluous relative to vanadium, hence, the calcium reacts with vanadium to form Ca(VO₃)₂, Ca₂V₂O₇ and Ca₃(VO₄)₂ orderly during the stone coal roasting process and high temperature is beneficial to the reactions between calcium and vanadium, which was validated by simulated reactions between pure calcium carbonate and vanadium pentoxide. These calcium vanadates are all water insoluble but acid soluble and this causes the low WLRV and relatively high ALRV. After calcium removal by HCl, the WLRV is highly enhanced and reaches about 50% when only 2% NaCl was added. If the HCl content is too high, the stone coal is easily sintered and the formed glass structure can enwrap vanadium, which leads the WLRV to decline. Single water leaching process is not appropriate to extract vanadium from high calcium type stone coal.

The inhibition effect of dimethylethanolamine (DMEA) and its composite with carboxylic acid was studied with the electrochemical tests. The experimental results indicate that DMEA is not a good inhibitor but the composite of DMEA with caprylic acid exhibits excellent inhibiting efficiency. The synergic mechanism of the organic corrosion inhibitors (OCIs) was studied with quantum chemical calculations. It is found that the DMEA forms a quaternary ammonium salt with the proton in carboxylic acid, and a cyclic complex formed between the salt and Fe may be responsible for the enhancement of inhibiting efficiency. The possible hydrogen bond formed between DMEA and carboxylic acid is not enough for the inhibiting effect. This work is helpful to proposing theoretical interpretation as well as developing a functional organic inhibitor to improve the durability of reinforced concrete contaminated with chloride.

Microstructural features including pore size distribution, cell walls and phase compositions of magnesium oxychloride cement foams (MOCF) with various MgO powders and water mixture ratios were studied. Their influences on compressive strength, water absorption and resistance of MOCF were also discussed in detail. The experimental results indicated that moderate and slight excess MgO powders (MgO/MgCl₂ molar ratios from 5.1 to 7) were beneficial to the formation of excellent microstructure of MOCF, but increasing water contents (H₂O/MgO mass ratios from 0.9 to 1.29) might result in opposite conclusions. The microstructure of MOCF produced with moderate and slight excess MgO powders could enhance the compressive strength, while serious excess MgO powders addition (MgO/MgCl₂ molar ratios = 9) would destroy the cell wall structures, and therefore decrease the strength of the system. Although MOCF produced with excess MgO powders could decrease the water absorption, its softening coefficient was lower than that of the material produced with moderate MgO powders. This might be due to the instability of phase 5, the volume expansion and cracking of cell walls as immersed the sample into water.

The micro-mechanical response of asphalt mixtures was studied using the discrete element method. The discrete element sample of stone mastic asphalt was generated first and the vehicle load was applied to the sample. A user-written program was coded with the FISH language in PFC3D to extract the contact forces within the sample and the displacements of the particles. Then, the contact forces within the whole sample, in asphalt mastic, in coarse aggregates and between asphalt mastic and coarse aggregates were investigated. Finally, the movement of the particles in the sample was analyzed. The sample was divided into 15 areas and a figure was drawn to show how the balls move in each area according to the displacements of the balls in each area. The displacements of asphalt mastic balls and coarse aggregates were also analyzed. The experimental results explain how the asphalt mixture bears vehicle load and the potential reasons why the rutting forms from a micro-mechanical view.

In order to understand the effect of powders ground from reactive sandstone replacing cement on reducing or suppressing alkali-silica reaction (ASR), and to identify the mechanism of suppressing ASR by this powders, mortar and paste containing reactive sandstone powders of four replacement levels ranging from 10wt% to 40wt% and four specific surfaces areas ranging from 210 m²/kg to 860 m²/kg were studied. The experimental results showed that incorporation of 40wt% reactive sandstone powders could suppress ASR effectively except for mortar containing reactive sandstone powders with specific surface area of 610 m²/kg, which disagreed with the most results reported that the higher reactive powder specific surface area, the smaller ASR expansion. By means of flame photometry, Fourier transform infrared spectroscopy (FT-IR) and thermo gravimetric analysis (TG), the mechanism of reactive sandstone powders on reducing or suppressing ASR was soluble alkalis type of reactive sandstone powders and the competition of liberating and bonding alkali of cement paste containing reactive sandstone powders, when the ability of alkali bonding was greater than the ability of alkali liberation, ASR caused by reactive sandstone was supressed effectively.

Recycled ceramic mixed sand (RCMS) was obtained by partially replacing ultra-fine sand with recycled ceramic coarse sand (RCCS). The effects of RCCS replacement rate on the apparent density, workability, compressive strength and splitting tensile strength of recycled ceramic concrete (RCC) were investigated. In addition, the relationship between the water-cement ratio and compressive strength of RCC was also studied. The experimental results indicate that the reusing of recycled ceramic aggregate can improve the cohesiveness and water retentiveness of fresh concrete and benefit the mechanical properties development. When the RCCS replacement rate is not less than 40%, the mechanical properties of RCC are superior to those of the reference concrete. Moreover, when recycled ceramic medium sand was completely used as fine aggregate, the maximum increase in both compressive strength and splitting tensile strength were obtained, comparing with those of reference concrete, the increment ratio was 19.85% and 32.73%, respectively. The microscopic analysis shows that the using of recycled ceramic aggregate can meliorate distinctly the structure of the interfacial transition zone (ITZ) and increase the compaction degree of cement paste. Furthermore, an expression of the compressive strength of RCC and the cement-water ratio is regressed and gains a good linear relativity. It is an effective way to recycle waste ceramic, and the consumption of recycled ceramic aggregate could reach from 26.9% to 47.6% of the total weight of aggregate in producing concrete.

The effect of carbonation on fatigue performance of ground granulated blast-furnace slag concrete was investigated. Based on the static compression tests of carbonated GGBS-concrete, the correlation between carbonation depth and compressive strength was analyzed and an equation between carbonation depth and compressive strength was put forward. Meanwhile, fatigue S-N curves of various carbonation depths were fitted, and the influence of carbonation on fatigue life and strength was studied. Carbonation has a dual effect on the fatigue behavior of GGBS-concrete. A fatigue equation based on the depth of carbonation was established. Also, the probabilistic distribution of fatigue life of carbonated concrete at a given stress level was modeled by the two-parameter Weibull distribution.

An accelerated laboratory method (saturated ammonium nitrate solution immersion method) was used to analyze the degradation of cement decalcification process. By studying the changes of intensity, volume, elastic modulus, quality, pH value, the Ca/Si, and mineral phase, it could be found that the first cement decalcification degradation process was the decalcification of calcium hydroxide, and then CSH gel, AFm, etc. The secondary ettringite deposition happened and the decalcification degradation depth was proportional to the square root of time. Moreover, the corresponding strength of cement would be gradually reduced, cement rock volume shrinkage occurred, pH values decreased, the surface elastic modulus decreased down to a certain level, and slightly changed and the Ca/Si was 3.1 from the beginning and lasted down to 1.3.

By measuring the expansion curves of a Nb bearing steel at different cooling rates by using Gleeble-3800 thermomechanical simulator, combining with metallographic analysis, different phase zones were determined. Also, precipitation behavior of Nb at different phase zones was investigated under ultra fast cooling conditions. The experimental results showed that adopting a proper deformation temperature, the ultra fast cooling process can restrain the precipitation of Nb at austenite phase zone. More quantities and smaller size precipitates of Nb can be found at the ferrite or bainite phase zone by controlling the ultra fast cooling ending temperature. With the increase of holding time at austenite, ferrite and bainite phase zones respectively, the volume fraction of precipitation, density, and average size of precipitates will increase obviously. With the decrease of early ultra fast cooling ending temperature, the density of Nb precipitates first increase (at ferrite phase zone) and then decrease (at bainite phase zone), the volume fraction of Nb precipitation decreases and precipitates can be refined. The optimal early ultra fast cooling ending temperature is located at ferrite phase zone. The combination of high rolling temperature with early ultra fast cooling technology opens the way for new cooling schedules and makes the production of high strength steels easier and cheaper by making full use of Nb precipitation strengthening effect.

NiCr micron-resistor was designed and prepared by magnetron sputtering and lithography on the substrate of silicon with different powers. It is found that there exists a big gap in the TCR between the annealed group and the un-annealed group. A series of tests were made to figure out the reasons lying behind the gap in the TCR between the annealed group and the un-annealed group. UV reflection results show that there is no increase in the concentration of free electrons after annealing. However, the data obtained from XRD reveal that the annealing does not have an obvious influence on the strain of thin films, but really increases the grain size of thin films. Therefore, the grain boundary scattering plays a dominant role in explaining the obvious difference in the TCR. Finally through appropriate methods, a micron-resistor for heating-up with a low TCR value was obtained.

TWIP steels with 70% cold-rolled reduction were heated at 500, 600, 700, 800, 900, 1000, and 1100 °C. Then, the properties before and after heating were examined through tensile and hardness experiments. The microstructures were also analyzed by optical microscopy and transmission electron microscopy. The relationship between the properties and microstructure was examined as well. Finally, the evolution process of cold-rolled microstructures during heating was discussed in detail. Moreover, some conclusions can be drawn, and the heating evolution characteristics are described.

Quenching experiments were performed at different cooling rates under non-directional solidification by differential thermal analysis, and the morphologic variation of primary phase, phase transition temperature and hardness change at the same quenching temperature were investigated. The experimental results show that, with the gradual decrease of the cooling rate from 25 K/min, the morphology of ferrite starts to transform experiencing the dendrite, radial pattern, Widmanstatten-like and wire-net. Sample starts to present the Widmanstatten-like microstructure at 10 K/min which does not exist at higher or lower cooling rates, and this microstructure is detrimental to the mechanical property. Except 10 K/min, the hardness decreases with decreasing cooling rate.

The effects of plastic deformation and H₂S on fracture toughness of high strength casing steel (C110 steel) were investigated. The studied casing specimens are as follows: original casing, plastic deformation (PD) casing and PD casing after being immersed in NACE A solution saturated with H₂S (PD+H₂S). Instrumented impact method was employed to evaluate the impact behaviors of the specimens, meanwhile, dynamic fracture toughness (JId) was calculated by using Rice model and Schindler model. The experimental results show that dynamic fracture toughness of the casing decreases after plastic deformation. Compared with that of the original casing and PD casing, the dynamic fracture toughness decreases further when the PD casing immersed in H₂S, moreover, there are ridge-shaped feature and many secondary cracks present on the fracture surface of the specimens. Impact fracture mechanism of the casing is proposed as follows: the plastic deformation results in the increase of defect density of materials where the atomic hydrogen can accumulate in reversible or irreversible traps and even recombine to form molecular hydrogen, subsequently, the casing material toughness decreases greatly.

Aiming at overcoming the difficulties in integral forming of thin-walled tubes with complex shapes, a novel forming method by inner and outer pressure through viscous was proposed. In this method, by dividing large deformation of the part into inner and outer pressure forming deformations, the limit deformation of tube part can be increased by several times. Meanwhile, the principle of viscous inner and outer pressure forming was provided, and key problems during the forming process such as reduction of the wall-thickness and instability wrinkling were analyzed. Thereby, the complex curved surface super-alloy GH3044 thin-walled tube with varying diameter ratio of 1.35 (the ratio between the maximum and minimum diameters of the part) can be integrally formed by this method. The experimental surface of the formed part is superior in quality and the wall-thickness distribution is uniform. The results show that the viscous inner and outer pressure forming can provide a new approach for integral forming of thin-walled tubes with complex shapes.

To obtain safety working before long-term early warning, we proposed a process for the preparation of luminescent films on metal substrate to detect the wear life. ZnO films were prepared on aluminum (Al) foils by the magnetron sputtering technique. The microstructure, tribological properties and photoluminescence (PL) spectra of ZnO films before and after the friction test were investigated. The microstructure of ZnO films grown on Al foils exhibited a closely packed hexagonal cone shape. ZnO films were grown along the orientation perpendicular to the substrate. The tribometric tests revealed that the average friction coefficient of ZnO films was lower and more stable than that of the substrate. The results of PL spectra indicated that the effect of Al element on ZnO films led to shifts of the defect related visible band. The luminescent center of ZnO films shifted from the emission peak at 510 nm before the friction to 647 nm after the friction, indicating that the green light shifted into the red light as the friction occurred. The visible light was helpful to understanding the failure characteristics during the friction and wear, and provide an early indicator of the impending failure.

A sensitive and selective method for the determination of ascorbic acid (AA) using [Cu(phen)₂]²⁺/multiwalled carbon nanotubes modified glassy carbon electrode was developed. Electrochemical behavior and surface characteristics of the modified electrode were studied using scanning electrode microscopy (SEM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The experimental results showed that the modified electrode enhanced the electrochemical response of AA and exhibited good analytical performance for AA determination from 10 to 1 042 μmol/L with a low detection limit of 9.67μmol/L (S/N=3). The modified electrode was also applied to the determination of AA in the Vitamin tablets and showed good recovery.

A novel biomimetic protein-resistant modifier based on cellulose-based polymeric liquid crystals was described (PLCs). Two types of PLCs of propyl hydroxypropyl cellulose ester (PPC) and octyl hydroxypropyl cellulose ester (OPC) were prepared by esterification from hydroxypropyl cellulose, and then were mixed with polyvinyl chloride and polyurethane to obtain composite films by solution casting, respectively. The surface morphology of PLCs and their composite films were characterized by polarized optical microscopy (POM) and scanning electron microscopy (SEM), suggesting the existence of microdomain separation with fingerprint texture in PLC composite films. Water contact angle measurement results indicated that hydrophilicity of PLC/polymer composite films was dependent on the type and content of PLC as well as the type of matrix due to their interaction. Using bovine serum albumin (BSA) as a model protein, protein adsorption results revealed that PLCs with protein-resistant property can obviously suppress protein adsorption on their composite films, probably due to their flexible LC state. Moreover, all PLCs and their composites exhibited non-toxicity by MTT assay, suggesting their safety for biomedical applications.

Ethylene glycol, glycerol, sorbitol, formamide, and urea were used as plasticizers for the preparation of thermoplastic starch (TPS) from corn starch. The properties of TPS were tested by analysis method. The results showed that TPSs were more highly plasticized with amines than alcohols. For the same type of plasticizer, the degree of plasticization decreased as the molecular weight of plasticizer increased. The relationship between plasticization degree and TPS properties was characterized and described by mechanical properties and water absorption. The experimental results showed that when the degree of plasticization increased, the tensile strength decreased and the elongation at breakage and water absorption increased.

A devised beating process was applied, which enabled the formation of slurry consisting of uniformly dispersed fibrillated polylactic acid (PLA) fibers with bamboo fiber, and the polymer material was obtained by a conventional papermaking process. Owing to the fast dewatering time, good repeatability and the facility to manufacture on a large scale, this process was used. It was revealed that the beaten PLA fiber was overall in machinery extrusion by the results of optical microscope and scanning electron microscope (SEM) observations. The improvement in the tensile index, burst index, tear index and other mechanical properties was considered as a key benefit as a result of adding bamboo fiber.

By using solution combustion synthesis method, several Li-Co delafossite catalysts were prepared via a highly exothermic and self-sustaining reaction. The prepared catalysts were characterized by XRD, SEM and the catalytic activities of the catalysts were evaluated by small sample experiment. It is shown that under loose contact conditions this catalyst can catalyze soot combustion at 360 °C, and the best prepared catalyst LiCo_0.9O₂ can ignite soot combustion below 300 °C. In the incompletely synthesized catalysts the Co cations shift to higher electrovalence, so the number of the surface adsorbed oxygen (O⁻) of the prepared delafossite catalysts increase and LiCo_0.9O₂ has the optimum catalytic activity.