We proposed a new approach to construct zeolitic imidazolate frameworks-67 (ZIF-67) powders directly on carbon cloth without any conductive agent and adhesion agent and the ZIF-67 nanoparticles on carbon cloth were successfully converted into hollow Co₃O₄ nanostructure via a facile calcination process. Compared with original ZIF-67 powders, the Co₃O₄@CC electrode materials had admirable specific capacitance of 1 164.8 F·g⁻¹ at an area current density of 2.5 mA·cm⁻². Furthermore, the rate performance remained 42.4% of initial value when the current density was increased to 30 mA·cm⁻² and the specific capacitance maintained 93.4% of initial capacity after 5 000 cycles at an area current density of 10 mA·cm⁻². This strategy may have potential prospect for the application of MOFs in the energy storage and conversion field.

We presented a simple yet convenient hydrothermal approach for the large-scale synthesis of uniform cylindrical silver (Ag) single-crystalline nanowires with diameters of about 25 nm and lengths of 1–4 µm. Poly(vinyl pyrrolidone) (PVP) was used as a reducing agent, and AgCl was used as a precursor to deliberately control [Ag⁺] at a low degree in the overall reaction process through its dynamic equilibrium by directly reducing AgCl with PVP at a quasi-equilibrium growth condition. The as-obtained products were characterized by powder X-ray diffraction (XRD) patterns, field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), infrared spectra (IR) and Raman spectra. Factors such as [PVP], reaction temperature, time, and species of reducing agents and precursors were investigated to have strong influences on the morphologies and structures of the resultant Ag nanostructures. The wire diameter can conveniently be adjusted between 25 and 50 nm by simply adjusting [PVP], reaction temperature and reducing agent species. The as-synthesized silver nanowires can be self-assembled into perfect order arrays after being dried on tin foil due to the PVP coating on the surface, the circular cross-section and the uniform diameter of the Ag nanowires. These special silver nanowires with a core-shell structure as well as their spontaneous self-assembly of order arrays are expected to provide potential applications in flexible conductors, dielectric materials, electromagnetic shielding materials and nano-devices.

A combination of experimental measurements and numerical analysis was utilized to study the low-velocity impact damage of domestic carbon fiber-reinforced composites (CFRCs). The results indicated that the low-velocity impact damage induced pits and longitudinal cracks on the front side, oblique cracks and delaminationin on the back side. The pit depth increased with the increasing impact energy. It was demonstrated that the numerical analysis strain history curve was similar to the experimentally measured strain history curve, which verified the accuracy of numerical analysis in which the Hashin failure criterion was used. The work provides basic data and theoretical basis for the promotion and application of the domestic carbon fiber, and demonstrates the feasibility of replacing imported carbon fibers with domestic carbon fibers.

Using lignite-based hypercoal as raw material, KOH as activator and CuO as microwave absorber, we prepared hypercoal-based activated carbons by microwave-assisted activation. The pore structure and the electrochemical performance of the activated carbons were tested, and the effects of adding CuO in the activation reaction process were also investigated. The activated carbons prepared were characterized by nitrogen adsorption-desorption, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The specific surface area and mesoporous ratio of the hypercoal-based activated carbon are 1 257 m²/g and 55.4%, respectively. When the activated carbons are used as the electrode materials, the specific capacitance reaches 309 F/g in 3 M KOH electrolyte. In comparison with those prepared without CuO absorber, the specific capacitance increases by 11.6%. It was proved that the addition of microwave absorber in microwave-assisted activation was a low-cost method for rapidly preparing activated carbon, and it could effectively promote the development of the pore structure and improve its electrochemical performance.

A novel solid-gas reaction preparation technology was used to adjust the composition and microstructure of the composite crystal materials by changing the preparation parameters. Compared with the commonly used sol-gel method, acid base neutralization sedimentation method, hydrothermal method, and gas phase deposition method, the technology was relatively simplified and the elemental composition was controllable, without the use of openings and additives. A kind of multi-element composite porous metal oxide was obtained by pre-intercalation and decarburization. In order to increase the porosity of MoO₃ material and promote the adsorption and diffusion of reactant molecules, the microstructure of MoO₃ was studied. The preparation process of porous molybdenum trioxide by solid gas combination process was discussed, which provides an innovative idea for the design and preparation of new materials with a large specific surface area and other desirable properties.

We obtained the reaction mechanism of cerium with oxygen by means of density functional theory (DFT) under the explosive or detonation situation. The energy level order of cerium was calculated and the potential energy profile was plotted. The properties of the bonds of all special structures in the reaction path were analyzed using the method of the electron localization function (ELF). The results indicate that the final reaction pathway can be expressed as Ce+O₂→FC→TS→IM→O-Ce-O, and the formation of Ce₂O₃ has not been found. In addition, the ELF diagram of the final product CeO₂ shows that Ce bonds with both O atoms and the bond angles <O, Ce, O> increase significantly.

Silicon carbide ceramics with different thicknesses/diameter ratios were prepared by using ultra-fine silicon carbide powder with the sintering additives of 1.0 wt% boron and 1.5 wt% carbon. The influence of thickness/diameter ratio on the microstructure and density of SiC ceramics was investigated in detail. The experimental results show that the addition of boron and carbon sintering aids can promote the densification process of SiC ceramic, leading to the low sintering temperature and improve mechanical properties. At 1950 °C, SiC ceramic with a density of 99% exhibits Young’s modulus, hardness, and flexural strength of 476 MPa, 28.3 GPa, and 334 MPa, respectively. It is found that long holding time has a positive effect on the uniformity of the microstructure and density distribution of SiC ceramics with large thickness/diameter ratios. Additionally, the sintering additive of boron can solid-solve into SiC, and then facilitate the phase transformation of SiC to form 6H-SiC and 4H-SiC composite ceramics.

Aluminum-matrix boron carbide (B₄C_p/Al) is a kind of neutron absorbing material widely used in nuclear spent fuel storage. In order to improve the tensile property of B₄C_p/Al composites, a new type of nano-Al₂O₃ particle (Al₂O_3np) reinforced B₄C_p/Al + Al₂O_3np composites were prepared by powder metallurgy method. The Monte Carlo particle transport program (MCNP) was used to determine the influence of Al₂O_3np on the thermal neutron absorptivity of composites. The universal material testing machine and scanning electron microscope (SEM) were used to study the mechanical properties, microstructure and fracture morphology of B₄C_p/Al composites. The results indicated that the neutron absorption properties of B₄C_p/Al composites were not affected by the addition of nano-Al₂O₃ particles in the range of 1 wt%–15 wt%. The addition of Al₂O_3np can obviously reduce the grain size of B₄C_p/Al matrix metals thus improve the tensile strength of the composites. The addition threshold of Al₂O_3np is about 2.5 wt%. Both B₄C_p and Al₂O_3np change the fracture characteristics of the composites from toughness to brittleness, and the latter is more important.

To investigate the transport characteristics of chloride ions in cement-based materials, the Mori-Tanaka (M-T) prediction scheme of the effective diffusion coefficient in composites containing single-phase and multi-phase inclusions is systematically deduced based on the theory of composite mechanics and porous medium. The volume fraction, morphology and distribution of aggregates, as well as the interfacial transition zone (ITZ) are fully taken into consideration in this proposed model. The results show that the algorithm of M-T prediction scheme with high accuracy is relatively simple.

Tetragonal zirconia (T-ZrO₂) ceramic nanopowders stabilized with 3 mol% Y₂O₃ were synthesized via polyacrylamide gel method, using ZrOCl₂·8H₂O and Y(NO₃)₃·6H₂O as raw materials. The effect of temperature on phase composition and morphology of YSZ nanopowders and sintering behavior of YSZ ceramics was investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Vickers hardness tester. The aging-resistance of YSZ ceramics was measured by means of aging experiments. The results demonstrated that the phase composition of YSZ ceramic nanopowders had no obvious change and it was composed of T-ZrO₂. Particle size of well-dispersed YSZ ceramic nanopowders increased from 17 to 35 nm with increasing calcining temperature from 600 to 800 °C. There was noticeable negative correlation between calcining temperature and the relative density of YSZ ceramic at the same sintering temperature. The aging experiments showed that water vapor facilitated tetragonal to monoclinic phase transformation, and the sample that had smaller grain size exhibited better aging-resistance. It can be concluded that when the calcining temperature is 600 C and sintering temperature is 1 550 C, the relative density and hardness of YSZ ceramic arrive at the peak of 96.64% and 11.135 GPa respectively, and it has less microcracks and excellent aging-resistance.

To promote the photocatalytic performance TiO₂ and enlarge its application in visible region, carbon doped TiO₂ (C/TiO₂) composites were synthesized by wet impregnation method using sucrose as a precursor and used for phenol photocatalytic reaction. The synthesized products were characterized by Nitrogen adsorption-desorption isotherms (BET), X-ray diffraction (XRD), transmission electron microscopy (TEM) and UV-visible diffuse reflectance spectroscopy (UV-vis) techniques. The results showed that the obtained TiO₂ was anatase phase in the C/TiO₂ products, and its crystallite size was 11.7 nm, respectively. Carbon amount and calcined temperature of C/TiO₂ can promote phenol removal. In this experiment, 5% carbon and 500 °C are the best choice for photocatalyst preparation. Under the UV light irradiation, 5%C/TiO₂ (500 °C, 2 h) exhibited the efficiency of 70.0% for phenol degradation within 150 min whereas TiO₂ (500 °C, 2 h) had 53.0% in the same duration of time. Also 5%C/TiO₂ (500 °C, 2 h) has higher photocatalytic performance under sunlight than pure TiO₂. A combination of factors that include the smallest crystalline size, higher anatase percent, less band gap energy value and more oxygen vacant resulted in higher photocatalytic activities of 5%C/TiO₂ (500 °C, 2 h).

The corrosion behavior and the effects of temperature on critical chloride content (C _crit) of steel fibers in RPC were analyzed by a pH meter, ion chromatography, mercury intrusion porosimetry (MIP), and electrochemical techniques. It was found that the suspension pH value, the chloride binding capacity, and the total porosity of RPC were lower than those of high-performance concrete (HPC). The pore structure of RPC mainly consisted of gel pores. The C _crit values of steel fibers in RPC and HPC at 20 °C were 1% and 2%, respectively. When the temperature reached 50 °C, the C _crit value of steel fibers in HPC decreased significantly, whereas it remained unchanged in RPC. The corrosion rate of corroded fibers in both RPC and HPC started to decrease with the rise in temperature.

A specially developed ultrasonic measurement apparatus (UMA) was used to in situ monitor the setting process of fly ash blended cement paste. Combined with the results of Vicat Needle tests, isothermal calorimetric measurement, XRD analysis, SEM morphology and compressive test, the influence of curing temperature (20, 40, 60, and 90 °C) and fly ash content (0,10%, 20% and 30%) on the setting and hydration process of fly ash blended cement paste was analyzed. The results show that setting and hardening process of fly ash blended cement paste at elevated temperature can be clearly identified into three stages including dormant stage, acceleration stage and deceleration stage. The increasing of curing temperature greatly accelerates the setting and hardening process. However, the content of fly ash does not have significant effect on the setting in condition of 90 °C. Besides, the initial and final setting time of cement paste is correspondent with the time of duration of dormant stage and the time of UPV value is 1 500 m/s (T1500), respectively. Thus, the UMA can be used to determine the initial and final setting time of cementitious material under different curing temperatures. The compressive test results indicate that the paste with 20% fly ash presents higher compressive strength than the plain paste at curing temperatures of 90 °C. Therefore, appropriate amount of fly ash is beneficial for concrete in the high temperature curing conditions.

The brine-freeze-thaw durability (defined as the durability under freeze-thaw cycles in Qinghai salt lake brine) of concrete (ordinary Portland cement concrete (OPC), high performance concrete (HPC-a), high performance concrete with steel fiber (HPC-b), and high performance concrete with high Young’s modulus polyethylene fiber (HPC-c)) was systematically investigated by the relative dynamic elastic modulus, the relative mass, the appearance, the scanning electron microscopy, and the X-ray diffraction. In addition, the low-temperature physical and chemical corrosion mechanism and a crack density model after the modified relative dynamic elastic modulus being taken into consideration were proposed. The results show that the deterioration of OPC is the severest, followed by HPC-a, HPC-c and HPC-b. The admixture or the fiber is mixed into concrete, which can improve the brine-freeze-thaw durability of concrete. The critical mass growth of the failure of concrete is 3.7%. The cause of the deterioration of concrete under the brine-freeze-thaw cycles is physical and chemical corrosion, not freezing and thawing. The crack density model can effectively describe the deterioration evolution of concrete.

Cement pastes containing 0%, 15%, 25% and 35% fly ash were prepared. After being cured for 90 days, all fly ash blended cement pastes were crushed and ground into powders with a particle size less than 80 µm and then the powders were immersed in alkali solutions. Adsorption characteristics of K⁺ and Na⁺ ions in the pastes were investigated. Meawhile, the desorption characteristics of the adsorbed alklai ions and the inherent K⁺ and Na⁺ ions in the pastes were also investigated. Results showed that the contents of K⁺ and Na⁺ ions adsorbed by the pastes increased with increasing the substitution levels of fly ash and/or the concentrations of alkali solutions. Each paste was characterized by having the same adsorption capacity for K⁺ or Na⁺ that was essentially independent of alkali concentration. Adsorption mechanism of K⁺ and Na⁺ ions by the pastes is believed to be an effect of charge compensation of the C-S-H gel. Adsorption-desorption of the adsorbed K⁺ and Na⁺ ions in the pastes is reversible. The inherent K⁺ and Na⁺ ions in the pastes entered rapidly into the deionized water during the first 120 minutes, and then they were released at a relatively slow rate. A steady-state alkali partition was reached at about 720 minutes. Some K⁺ and Na⁺ ions which were originally “bound” by the hydration products were considered to be released into de-ionized water. Leaching tests showed that there was no significant effect of fly ash on the retaining of available alkalis in the pastes. A part of the released alkali ions exists in the pore solutions and the other part may be physically adsorbed by the hydration products.

The binder properties were determined in accordance with Chinese standard such as ductility test, which allowed to measure the distance in centimeters that a standard briquette of asphalt had been stretched before breaking. Then, penetration test was carried out in order to know some properties of the asphalt, which are the hardness and the softness. Finally, softening point test was carried out in order to determine the temperature at which the bitumen attains a particular degree of softening under the specification of the test. According to Chinese standard for performance tests, firstly, Marshall test was carried out in order to measure the theoretical density, air voids, voids filled with asphalt, stability, flow, and voids in mineral aggregate of asphalt specimens. Secondly, Freeze-thaw splitting test was carried out in order to determine Splitting strength ratio. Finally, dynamic stability (rutting) test was carried out to determine average dynamic stability. Beside the tests carried out, the gradation of the extracted aggregate in accordance with American Association of State Highway and Transportation Officials was carried out to determine the dimensions of the particles weight distribution. Furthermore, both the percentage of recycled asphalt pavement materials and binder in mixture were determined to know how much of the new material during the mixture was needed. However, two specimens were used to evaluate the performance of recycled asphalt pavement materials. One specimen of recycled asphalt pavement materials was ten years old, and another one of recycled asphalt pavement materials was five years old. The results show that the conditions of the environment such as moisture, temperature, and age, decrease the ductility and penetration properties of binder when increase the softening point property of binder. Then the gradation of recycled asphalt pavement aggregate is of the required values to reuse in the mixture, while the flow ratio, the splitting strength ratio, and the dynamic stability ratio, are less than the required value test. With regard to the properties of mixture of recycled asphalt pavement material binder with rejuvenator, the results show that when the penetration and ductility versus percentage of rejuvenator increase, softening point versus percentage of rejuvenator decreases. Also, when the bitumen and rejuvenator percentage increase, the air voids decrease. Consequently, voids filled with asphalt and voids in the mineral aggregate increase. Moreover, the theoretical density and stability values decrease in a mixture containing four-point fifty percent to six percent of bitumen and rejuvenator, whereas the flow values increase. More interestingly, with four percent to four-point fifty percent mixture ratio of bitumen and rejuvenator, density, stability, and flow values increase. The splitting strength ratio values of mixtures and the dynamic stability test (rutting test) values of mixtures with forty percent of specimen one and specimen two respectively are greater than the required value of the standard test. In addition, the high percentage of rejuvenator increases the rut of pavement, in the same manner, the low percentage of rejuvenator induces low rut. In conclusion, the binder content from recycled materials without rejuvenator seems not be sufficient to be reused on the new pavement while the aged recycled material seems to be performed better than no aged recycled material with rejuvenator into bitumen. Then, the rejuvenator can influence the bitumen properties and performance of the pavement. Finally, the pavement made by only recycled pavement materials as a base layer appears to be more economical but cannot be more effective than the pavement made by mixture of new and recycled pavement materials as a base layer.

Five kinds of mortars with density grades of 500, 600, 700, 800, and 900 kg/m³ were prepared. Their thermal conductivity and compressive strength were measured, and the morphological changes before and after simulated tunnel fire were observed. To investigate the fire resistance, the interfacial temperature of a 30 mm thick aerogel-cement mortar and self-compacting concrete (SCC) in a simulated tunnel fire with the maximum temperature of 1 100 °C for 2.5 h was tested and recorded. The results showed that as the density decreased, both compressive strength and thermal conductivity of the aerogel-cement mortar exhibited an exponential decrease. The effective fire resistance time of the mortar with 500, 600, 700, 800, and 900 kg/m³ for protecting SCC from tunnel fire were 97 min, 114 min, 144 min, > 150 min, 136 min, respectively. 700–800 kg/m³ was the optimum density for engineering application of tunnel concrete fireproof coating.

A new hot mixed epoxy asphalt system was developed. The reaction process of epoxy resin was characterized by Fourier transform infrared spectroscopy (FTIR). The viscosity was investigated by Brinell viscometer when epoxy resin was mixed with asphalt. The glass transition temperature (T _g), homogeneity, thermal stability and viscoelasticity of epoxy asphalt were analyzed by differential scanning calorimetry (DSC), metallographic microscope, thermogravimetric (TG) and dynamic mechanical analysis (DMA). The results showed that the viscosity of epoxy resin modified asphalt reached 1 000 mPa·s for more than 180 minutes at 180 °C, while the best construction process is mixing at 180 °C for 2 hours and curing at 60 °C for 4 days. The particle size of asphalt is less than 50 µm. In addition, the mechanical properties of the materials are uniform within the specified pavement thickness.

Triisopropanolamine (TIPA) was used as an early strength component to study its effects on mortar strength, cement paste setting time and early hydration characteristic of cement. And the early strength mechanism of TIPA at low temperature of 5 °C was also discussed. The results showed that, at 5 °C, the incorporation of TIPA promoted the condensation of cement paste, shortened the initial and final setting time, and accelerated the strength development of specimens at all ages, among which the strength after 3 d increased significantly. The 1, 3, 7, and 28 d compressive strength ratios of the mortars mixed with 1% TIPA could reach 196%, 179%, 160% and 110% respectively, and the mortar strength after 3 d exceeded that of the contrast sample cured at 20 °C. Under low temperature condition, TIPA could promote the hydration reaction of cement, shorten the induction period and advance the acceleration period. Furthermore, the maximum heat release rate and cumulative heat release quantity would be all increased, and the cumulative heat release of the cement mixed with TIPA hydrated for 12 h and 7 d increased 73% and 38% respectively. TIPA could shorten the nucleation and crystal growth (NG) stage and increase its hydration degree significantly, so it promoted cement hydration reaction. Additionally, the hydration reaction rates in phase boundary reaction (I) phase and diffusion reaction (D) phase were increased, and the duration of I process was prolonged, thereby the development of specimen strength would be accelerated. TIPA did not obviously change the types of hydration products, but increased the content of Ca(OH)₂ in the samples and the degree of cement hydration. After hydration to 7 d, large amounts of hydration products, whose surface was smooth, were formed and bonded into sheets, and the structural density of samples improved significantly.

BiOI nanosheets with high sorption capacity were successfully prepared by the simple hydrothermal method followed by calcination. The features of the as-obtained BiOI nanosheets were characterized by X-ray diffraction (XRD), Fourier transform infrared spectra (FT-IR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and specific surface area analyzer (BET). BiOI was used as an adsorbent to explore its sorption properties of benzidine by changing initial concentration, pH and time. Results showed that BiOI had high sorption activity for benzidine, and it was found that the BiOI in this paper exhibited higher sorption capacity than traditional BiOI, which could be mainly attributed to the large specific surface area of the sample and the existence of unsaturated sites in the sample. Meanwhile, the optimal sorption conditions were explored, the actual maximum sorption capacity of BiOI could reach 66.67 mg/g. In addition, the synthesized sample’s reusability without obvious deterioration in performance was demonstrated by five cycles. The sorption process was in accordance with the Langmuir model and the pseudo-second-order kinetic model.

To study the effect of some parameters, such as, length and fraction of glass fiber (GF), and the fraction of maleic anhydride grafted polypropylene (PP-g-MAH), on the mechanical properties of glass fiber reinforced polypropylene (GF/PP) composites, tensile tests, bending tests and impact tests were conducted. Scanning electron microscope (SEM) was used to characterize the fracture mechanisms of the composites. The results show that, compared with 3 mm GF, 9 mm GF can significantly improve the strength of the composite better. Addition of PP-g-MAH, a kind of grafting agent, into the PP-30% LGF composite can result in a better mechanical properties because of the strengthening of the bonding interface between the matrix and the fiber. When the mass fraction of GF is 30% and the PP-g-MAH fraction is 6%, the mechanical properties of the composite are the best.

The effect of homogenization treatment on the corrosion behavior and corrosion mechanism of Mg-Y alloys in 3.5 wt% NaCl solution was investigated by electrochemical characterization, immersion testing and SEM observations. The diffusion kinetics model of Mg-Y alloy was established, and the homogenization system was determined. With increasing of homogenization temperature and time, the Mg₂₄Y₅ phase gradually decreased, which increased the self-corrosion potential and the high-frequency arc radius. The corrosion resistance of the five alloys could be given as follow: Mg-0.25Y < Mg-8Y < Mg-15Y < Mg-5Y < Mg-2.5Y. The Mg- (0.25, 2.5 and 5) Y show localized corrosion in a wide range and small depth, while Mg- (8 and 15) Y showed localized corrosion in a smaller range and larger depth.

The semisolid A356 alloy strip was prepared by a novel continuous micro fused-casting process. The microstructure evolution and mechanical property of A356 aluminum alloy strip with different nozzle temperatures were investigated. The nozzle temperature had great influences on the microstructure and property primarily accompanied with the crystal change in the fused-casting area through the cooling conditions. The results showed that the semisolid A356 alloy strip samples fabricated by micro fused-casting demonstrated good performances and uniform structures with the nozzle temperature at 593 °C and the stirring velocity at 700 r/min. The fine grains of the primary α-Al phase with average grain size of 51 µm and shape factor up to 0.71 were obtained under the micro fused-casting process, and the ultimate average vickers hardness came up to 83.39±0.89 HV, and the tensile strength and elongation of the A356 alloy strip reached 245.32 MPa and 7.85%, respectively.

We have developed a controlled-release drug carrier. Smartly controlled-release polymer nanoparticles were firstly synthesized through RAFT polymerization as the controlled-release core. The structural and particle properties of polymer nanoparticles were characterized by nuclear magnetic resonance spectroscopy (¹H-NMR), scanning electron microscope (SEM) and X-ray spectroscopy (EDX). Mesoporous materials were selected as the shell materials to encapsulate the smart core as the stable shell. The mesoporous shell was characterized by transmission electron microscopy (TEM) and scanning electron microscope (SEM). All the results showed that a well-defined core-shell structure with mesoporous structure was obtained, and this controllable delivery system will have the great potential in nanomedicine.