The tension mechanical properties of the [001]  β--SiC nanowires with different cross--sections were investigated using molecular dynamics simulation with Tersoff bond--order interatomic potential. The stress--strain curves were obtained and analyzed in order to elucidate the scale effect on the mechanical properties of the nanowires. The simulation results show that the  β--SiC nanowires exhibit large plastic deformation for at least 11% under axial strain at room temperature, which is rarely observed for their macro counterparts
especially at low temperature. It is also found that the influence of the cross section size of the nanowires on the mechanical properties is remarkable; with increasing of the size the tensile strength and Young's modulus of the nanowires increase.

In order to obtain the spatial distribution and its variation with time during the galvanic corrosion of hot dip galvanized steel if scratches occurred in the zinc coating, the heterogeneous wire beam electrode composed of zinc and mild steel wires was developed, and then the potential and current distributions of this electrode were acquired at different time. The results showed that zinc wires can provide enough cathodic protection to steel wires in seawater when surface area of zinc wires is ten times that of steel wires. The potential and current distributions were inhomogeneous among the zinc wires. The similar heterogeneous phenomenon also presented among the steel wires, and the hydrogen evolution occurred on their surfaces.

The corrosion behavior of three Fe--15Cr--xAl(x=0, 5, 10%) alloys below KCl--ZnCl₂ deposits in air was investigated at 600℃. Compared to their oxidation in air, all the alloys suffered from enhanced corrosion with the formation of non--protective porous scale, particularly in combination with internal attack of matrix. The corrosion rates decreased with increasing aluminum content. The effect of aluminum was mainly attributed to the enrichment of Al₂O₃ in the inner region of the scale, which may act as a barrier by retarding the rapid migration of the reactants.

Si nanocrystals have been fabricated in SiO₂ film using ion implantation followed by high-temperature annealing. The microstructure and optical properties of the samples with different Si⁺ implantation doses were investigated, and the growth mechanism and light emission mechanism were explored. The experimental results indicated that for small Si nanocrystals (<5 nm), the growth mechanism conforms to Ostwald ripening; while for the big ones (>10 nm), the coalescence of small nanoparticles through twinning is dominant. The
photoluminescence (PL) investigation showed that the PL spectrum intensity from the sample with an implantation dose of 3 ×10¹⁷/cm² dropped by a factor of 5 compared with that from the sample with an implantation dose of 8×10¹⁶/cm² . The correlation between microstructure and PL indicated that the microstructural defects, such as twinning and stacking faults inside the Si nanocrystals have a great influence on the PL intensity.

The MM200 friction tester was used to investigate the wear life of 3Cr13 coating prepared by high velocity arc spraying technique under dry friction. By use of constant–stress accelerated model, the relationship curves between the wear life and the three condition factors (load, coating thickness, rotational speed) were established respectively. The preliminary model of the wear life prediction of 3Cr13 coating was
constituted by multiple regression analysis, and correlation analysis of the influencing factors were carried
out at the same time. The results indicated that the cohesive delamination of coating was caused by the
increasing load. The adhesive delamination of coating was a result of decreasing of coating thickness. The
degree of furrow and micro–cutting was determined by rotational speed. The plain sequence of factors,
affecting wear life of the coating was the coating thickness, load, rotational speed.

Ultra–fine Mo–30Cu composite powders with the diameter of 17–30 nm were fabricated by sol–spray drying calcination and subsequent hydrogen reduction process. A series of phase transition occured during the preparation process of the composite powders, composite oxides of CuMoO₄ and MoO₃ were obtained after the compound–precursor Cu_7.6O₈ (NO₃)+(NH₄)₂ (Mo₄O₁₃)+(NH₄)₆(Mo₇O₂₄)(H₂O)₄+ Cu₄ Mo₅O₁₇+CuMoO₄ were calcined, and then changed into MoO ₂+Cu₂O+Cu after reduction at 300 ℃, and at last transformed into Mo+Cu composite powders after reduction at 700℃. Densification behavior during sintering, mechanical property and microstructure of the alloy were investigated. The metastable Mo(Cu) solid solution gradually changed into Mo and Cu during the green compact sintering in temperature range of 1050℃ to 1200℃. The fine grained alloy whose relative density can be up to 99.7% was achieved after Mo–30Cu composites sintered at 1050℃ for 60 min in H₂ atmosphere. The maximum tensile strength and elongation rate of the alloy are 755 MPa and 15.8%, respectively.

This study was concerning the carbonation and modification of carbon coating method of LiFePO₄. The structure and the electrochemical performance were characterized by TG-DTA, XRD, TEM and electrochemical performance testing. The results showed that different molecular weights and structures of the carbon sources resulted in different decomposition temperatures and structures of carbonized products, and the electrochemical performance of the LiFePO₄/C composite materials was effected by different carbon sources also.

The tensile tests were carried out to study the strain hardening behavior of a high manganese TRIP/TWIP steels with 18.8% manganese. The results indicated that, strain hardening behaviors are different during the deformation process. True stress-strain curve obeys Hollomon relationship partly. TRIP effect occurs in the initial plastic stage, and the strain hardening exponent in this stage is a constant. However, the value of n increases with true strain ε increasing, when true strain is between 0.14 and 0.35. Then the value of d2σ/dε2 is above zero. A lot of deformation twinning can be found, and the micro mechanisms are twins induced plasticity. TWIP effect dominates this stage. The mechanism of the last stage is some TRIP effect, and both phases have occurred plastic deformation.

In accordance with preparation process of open-cell aluminum foam, a novel simplified model of pore s structure was proposed to exploit the performance of the through-holes, which connect neighboring cells, on the elastic module and compressive collapse stress of porous aluminum alloy. It is shown that the results coincide with experiments in terms of elastic module and plastic collapse stress. Stress concentration neighboring the through-hole between neighboring cells was manifested by unit cell model. On account of significant effect of through-hole’s variation on porosity, the sensitivity of mechanical properties of open-cell aluminum alloy on porosity could be explained by stress concentration on the through-hole between neighboring cells.

As a novel kind of sensor and actuator materials, Ionic Polymer Metal Composite (IPMC) has been used in more and more engineering applications fields. And it is urgent to properly model IPMC considering electromechanical relationship to describe its properties. In this paper, an electromechanical model based on nonreversible thermodynamics and pure bending theories was proposed to describe and predict the electrical/mechanical performance of IPMC. The compact description was exhibited by the linear regime with two driving forces (electric field E and pressure gradient ∇p). The model was developed to account for the coupling of ion transport, electric field and elastic deformation to predict the response of the IPMC. The pure bending theory was used to approximately describe the stress characteristic of IPMC. The electromechanical model can explain the actuation and sensing effect of IPMC. The experiment results showed that the model can predict the IPMC responses under DC excitation with the error are within.

La_0.7Sr_0.3MnO₃ (LSMO) target has been prepared by a Sol–gel method and the film of LSMO with the thickness of 187 nm has been deposited on a (012)–oriented LaAlO₃ substrate using the pulsed laser deposition technique. The transport and photoinduced properties of the LSMO film at different annealing conditions have been investigated. The phase transition temperature decreases and the electrical resistivity of the film increases with increasing the annealing time. Photoinduced properties show that the laser induces the increases of the electrical resistivity in the metallic phase and the reduction in the insulation phase. The photoconduction (Δρ) increases, and then decreases with increasing the annealing time. It is found that there exists the max photoconduction about 0.013 Ωcm for the sample with the 40 minutes vacuum annealing, which is attributed to double exchange interaction.

Butyl methacrylate/styrene copolymer was synthesized with butyl methacrylate and styrene monomer by suspension polymerization, with BPO as initiator. The spinning liquid was prepared by dissolving synthetic copolymer into dimethyl acetylamide (DMAc) and then spun into fibers. The fiber with absorption function was obtained. The methacrylate/styrene copolymer were characterized by FTIR and ¹H nuclear magnetic resonance (NMR) spectrometer. The related performance of copolymer fiber were analysized by thermogravimetric analysis (TG), dynamic mechanical analysis (DMA) and single–wire power equipment. It showed that BMA/St70/30 copolymer fiber which had better absorptive ability for specific kinds of oil was prepared had good performance. Its per gram methacrylate/styrene copolymer fiber saturated absorbency of kerosene, petroleumether, gasoline was 3.7 g kerosene/g copolymer fiber, 5.3 g petroleum/g copolymer fiber, 4.1 g heptane/g copolymer fiber respectively.

Ceria–based precursors doped with calcium, calcium–samarium and calcium–gadolinium were prepared by an improved homogeneous precipitation method using ammonium oxalate as precipitant, high purity reagents Ce(NO₃)₃·6H₂O, Ca(NO₃)₂·4H₂O, Sm₂O₃ and Gd₂O₃ were used as raw materials, urea was used as pH adjuster of the mixed solution. The as–synthesized precursor were calcined at 700 ℃ for 4.5 h. The calcined powders were characterized by X–ray diffraction (XRD), scanning electron microscopy(SEM), and Brunauer–Emmett–Teller(BET) specific surface area measurements. The results show that the calcined powders have satisfactory characterizations when the initial hydrolysis pH is approximately 1, the total concentration of mixed cation ions is 0.5 mol/L, and the initial concentration of precipitant is 0.05 mol/L. The powders after calcined have a single cubic fluorite crystalline structure and higher phase purity, with spherical nano–sized particles about 34–39nm in diameter and narrow size distribution. In this study, doped ceria precursors were redispersed and washed in ethanol can alleviate the degree of agglomeration of the calcined powders.

SiC thin films were grown on Si substrates by magnetron sputtering. The structural and component changes of the films, pre and post high temperature annealing at different temperature and atmosphere conditions, were studied. The results show that the films are characterized by the amorphous microstructure and mainly composed of Si–C bondings, C–C bondings as well as a small mount of oxide impurity consorted with Si; the content of the C–C bondings decreased after annealing in vacuum, meanwhile the Si–C bondings content increased, annealing in vacuum is beneficial to the formation of SiC; after annealing at 800℃ in air, a thin dense layer of SiO2 formed on the surface, which prevented the oxygen from contacting with the film and effectively protected the inner SiC from oxidizing. SiC films have good thermal stability at 800℃ in air.

By means of two elementary parameters, a method has been put forward to calculate the specific surface area from porosity and pore diameter for metal foams. Using the relevant mathematicalphysical relationship between the specific surface area and the elementary parameters of porosity and pore diameter, the specific surface areas of two classes of metal foams, which were respectively prepared by different technologies of electrical deposition and high pressure permeating casting, are successfullycalculated out.

Microarc oxidation (MAO) coatings on magnesium alloy were prepared in silicate electrolyte under constant voltage mode. Cross-section morphologies, binding force and corrosion resistance of the coatings treated by micro arc oxidation and electrophoresis or direct electrophoresis were studied, respectively. The results show that electrophoresis coating can be prepared on the surface of MAO coating, and this technique is simpler than the traditional electrophoresis. The forces of physical binding and chemical bonding of the composite coatings were formed, and the grade of binding force is NO.1. The corrosion weight and surface morphology of the composite coatings are not changed under the neutral salt spray test for 800 h. The electrochemical stability of the microarc oxidation and electrophoresis coating is better, and corrosion current is decreased by 5 or 2 grades compared by the ceramic coating or direct electrophoresis coating.

NiOx electrochromic films with small grain size (<22 nm) have been prepared by using a liquid-nitrogen-cooled apparatus with a magnetron sputtering installation being equipped. When identical deposition parameters have been employed, relying on liquid nitrogen cooling substrates, the grain sizes of films can be controlled and reduced. The results showed that the electrochromic performance and the O/Ni rate of NiOx film prepared with cooling substrate were superior to that of NiOx film deposited without cooling substrate.

In order to understand the fundamental characteristics of thermocapillary convection in the detached solidification under microgravity, the finite-difference method is used to carry on numerical simulation. The result shows that: when Ma is small, the flow of molten liquid is steady and it only exists near the free surface. And with Ma increasing, the flow is expanded toward the inner part of molten liquid gradually and the velocity of flow on the free surface increases. On the contrary, the flow is unstable when Ma exceeds the critical Ma. The physical mechanism of this unstable thermocapillary convection can be explained as: there is a hysteresis between the variety of the velocity and the variety of the resistance.

The alloy with nominal composition Ni–33Al–31Cr–2.9Mo–0.1Hf–0.05Ho (%) has been directionally solidified by liquid metal cooling (LMC) and conventional high rate solidification (HRS) processes. Investigations reveal that the directionally solidified alloys are composed of primary dendritic NiAl, NiAl/Cr(Mo) eutectic cell and Hf solid solution. Compared with the conventional high rate solidification process, the liquid metal cooling process can provide higher thermal gradient and higher cooling rate. Higher thermal gradient widens the composition range of coupled zone and reduces the volume fraction of primary dendritic NiAl. Higher cooling rate restrains the diffusion and results in the refinement of the microstructure and the expansion of total contents of the solid solution elements (except Si) in NiAl and Cr(Mo) phases. In addition, casting defects including freckles, misoriented primary dendritic NiAl grains and discontinuities of primary dendritic NiAl grains decrease or even disappear completely in the directionally solidified alloys processed by liquid metal cooling process.

The three–point–bending fatigue behaviors of a new kind of Nb+V micro–alloyed forging steel for truck front axle have been studied by hydraulic servo fatigue testing machine. The effects of specimen size on the fatigue behavior and its origin have been considered. The S–N curves were plotted and the fatigue cracked surfaces were analyzed by SEM. The results showed that the specimen size has a significant influence on three–point–bending fatigue limit. The three–point–bending fatigue limit of specimen increased with decreasing the specimen size. There is little effect of specimen size on the morphology of fatigue fractured surfaces. The reasons for this specimen size effect are that there exist stress gradient in specimen for three–point–bending fatigue test and that the stress gradient in a smaller specimen is larger than that in a larger one.