An economic and green approach for the controllable synthesis of porous functionalized graphene materials as microwave absorbers was proposed in this paper. POROUS RGO@Ni nanocomposites were synthesized by a simple one-pot method based on solvothermal treatment of Ni(acac)₂ and graphene oxide without adding additional reducing agents. The structure and morphology of the as-prepared hybrid materials were characterized by XRD, Raman spectroscopy, XPS, VSM, SEM and TEM. The results show that uniform Ni spheres of about 900 nm in diameter homogeneously distributed on graphene sheets and form a porous structure. The electromagnetic data demonstrated that RGO@Ni nanocomposites exhibited significantly excellent electromagnetic wave (EMW) absorption properties, probably originating from the unique 3D porous structure and synergistic effect. The minimum reflection loss (RL_min) and maximum effective absorption bandwidth (EAB) of RGO@Ni nanocomposites are -61.2 dB and 6.6 GHz, respectively.

PbTiO₃ (PTO) ferroelectric thin films were synthesized by a sol-gel process, where different concentration (0.2%, 0.5%, 0.8%, mole ratio) of PbTiO₃ nanoplates with large spontaneous polarity were introduced to the sol system to manipulate the growth and microstructures of PbTiO₃ films. The products were then characterized by means of X-ray diffractometer(XRD), scanning electron microscope (SEM), transmission electron microscope (TEM). The effect of PTO nanoplates on the growth mechanism of PTO films was investigated by in-situ XRD. It was found that nanoplates dramatically affected the growth process and crystallographic orientation of PbTiO₃ films, giving rise to a preferred orientation of (100) in PbTiO₃ films. In addition, an effective control of grain size of PbTiO₃ films ranging from 100 nm to 2 μm has been realized by altering the concentration of nanoplates. According to results of SEM, TEM and in-situ XRD analysis, the grains in solid-state films exhibited the growth characteristics of orientation related gathering of gains, similar to that in liquid phase. This growth behavior can be attributed to the strong electrostatic force originated from polar surfaces of nanoplates, which induced the adsorption and oriented alignment of small grains, accounting for the orientation and grain size evolution.

Regarding to conditions of the fusion-related tungsten (W) divertor, the etching behavior of polycrystalline W under the irradiation of low-energy and high-flux hydrogen ions, namely the flux of ca 10²² ions/m²·s, dose of 1.0×10²⁶ ions/m² and energy of 5~200 eV was investigated by means of scanning electron microscopy SEM with EBSD and conductive atomic force microscopy. The findings suggest that the sputtering yield of W is strongly dependent on the ions energy, the sputtering rate increases rapidly with the increase of H ions energy; After irradiation, a texture of parallel stripes with a special orientation for every grain may emerge on the irradiated surface, but the distribution of defects on both sides of every stripe is obviously different, which means that the etching of W surface is preferentially occur along a certain face of W crystal grains.

The hot deformation behavior of electron beam cold hearth melting TC4 Ti-alloy at 850~1100℃, by strain rate 0.01~10 s^-1 were investigated through a series of thermal simulation compression experiments via Gleeble-3800 thermal simulator. According to the true stress-true strain curve, the influence of deformation parameters on rheological stress was analyzed, and the Arrhenius constitutive model and DMM processing maps was established. The results show that the flow stress decreases with the increase of deformation temperature, and the flow stress decreases with the increase of strain rate. The hot deformation activation energy was Q=746.334 kJ/mol and Q=177.841 kJ/mol for the TC4 Ti-alloys composed of (α+β) two-phase and β phase respectively. The error analysis of the model was carried out by correlation coefficient method and relative average error. The correlation coefficient R²=0.995 and the relative average error AARE=5.04%, which indicates that the established model is accurate and can accurately predict the thermal deformation flow stress. The best processing area of the alloy is within the temperature range of 1000~1100℃ and strain rate range of 0.01~0.1 s^-1.

Nanocellulose adsorbent (AA/AM-g-NC) from cotton linter was successfully prepared by high pressure homogenization with the assistance of an ionic liquid. The cotton linter was first swelled, hydrolyzed and grafted with acrylic acid and acrylamide in an ionic liquid (1-butyl-3-methylimidazolium hydrogen sulfate ([Bmim]HSO₄)), and then further treated by high pressure homogenization and finally AA/AM-g-NC was obtained. The AA/AM-g-NC adsorbent was characterized and used as adsorbent to adsorb methylene blue. The results show that after the treatment of high pressure homogenization assisted with hydrolysis and graft in ionic liquid AA/AM-g-NC illustrated as crosslinked net with fibril. The crystalline of AA/AM-g-NC remained as cellulose Ⅰ type, with a little increase in the crystallinity. The appearance of functional group from acrylic acid and acrylamide on the AA/AM-g-NC surface was proved. The sorption process towards methylene blue was pH value dependent, spontaneous, exothermic and followed the Langmuir adsorption isotherm. And the adsorption kinetic is closer to the quasi-second order kinetic equation and controlled by both intraparticle diffusion and surface diffusion.

Transparent MSe₂@N-doped carbon film was synthesized using a metal metalloporphyrin (M-TCPP, M=Ni,Fe) thin film as a template in the presence of selenium powder in nitrogen atmosphere, and the MSe₂@N-doped carbon film was used as the counter electrode (CE) in Co-mediated bifacial dye-sensitized solar cells (DSSCs). The morphology, structure and electrochemical performance of MSe₂@NCF were characterized, while the difference of charge transfer process and photovoltaic performance of the cells was discussed when irradiated at the front and rear of the DSSC. The NiSe₂@N-doped carbon film achieves admirable PCEs of 8.19% and 6.02% when irradiated at the front and rear of the device, respectively, which is comparable performance to that of a cell with a Pt CE (PCEs of 8.46% and 6.23%).

A novel dual-network hydrogel AG/PVA/CB[7] was prepared with natural polymer agarose (AG) as the first physical crosslinking network, polyvinyl alcohol (PVA) as the second physical crosslinking network, and cucurbituril[7] (CB[7]) as the crosslinking agent. The morphology, structure, crystallinity and crosslinking mode of the AG/PVA/CB[7] hydrogel were characterized by SEM, FT-IR and XRD. The mechanical properties, swelling properties and re-healing properties of the hydrogel were investigated. The results show that the hydrogel presents high strength and re-healing properties. The mechanical properties of the hydrogel may be enhanced by cross-linking the polymer chains with hydrogen bonds and microcrystals. The mechanical properties of the hydrogel were not only increased with the increase of freeze-thaw times but also improved by the addition of crosslinking agent CB[7]. After 5 freeze-thaw cycles, the hydrogel presents tensile strength of 0.37 MPa, young's modulus of 0.23 MPa and equilibrium swelling rate of 140%.

Low-cycle fatigue behavior for two type of specimens, sampling along rolling direction (RD) and transvers direction (TD) respectively of the rolled sheet of Al-5.4Zn-2.6Mg-1.4Cu alloy was comparatively assessed at room temperature. The results show that for all imposed total strain amplitudes the alloy along both RD and TD directions exhibits the stable cyclic stress response behavior. The cyclic stress amplitude of the alloy along TD direction is higher than that along RD direction for the same total strain amplitude, while the fatigue life of the alloy along RD direction is significantly longer than that along TD direction. For the Al-5.4Zn-2.6Mg-1.4Cu alloy sheet, the plastic strain amplitude and elastic strain amplitude are linearly related to the number of reversals to failure. In addition, under the loading condition of low-cycle fatigue the fatigue cracks initiate transgranularly at the free surface of fatigue samples and propagate transgranularly.

The effect of double quenching and tempering (DQT) treatment as well as the conventional quenching and tempering (CQT) treatment on the microstructure and impact toughness of a high strength low alloy steel were investigated. The results show that compared with the CQT treatment, the impact toughness improved a lot, while the yield strength just slightly decreased for the DQT treated steel. These changes were characterized by optical microscope (OM), scanning electron microscope (SEM), electron back scatter diffraction (EBSD) and transmission electron microscope (TEM). It follows that in comparison to the CQT treatment, the DQT treatment led to a finer microstructure, namely, the size of prior austenite grain and the effective grain were refined, and the density of the high angle misorientation was increased, while the frequency of deflection for the crack propagation for the DQT treated steel was much higher than the CQT treated one. The superior toughness of the DQT treated steel can be attributed to the finer microstructure.

In order to simulate the nitriding corrosion behavior of ferritic stainless steels in selective catalytic reduction (SCR) system of commercial vehicle, urea corrosion tests were carried out on three ferritic stainless steels (436L, 439M and 441) used in exhaust system of commercial vehicles. The influences of alloy composition and inclusions on high temperature urea corrosion resistance of ferritic stainless steels were investigated. The results show that under the synergistic effect of high temperature fatigue and oxidation, the high temperature and high nitrogen environment results in the rapid precipitation of chromium nitride particles at grain boundaris and in the local area of the ferritic stainless steels, resulting in chromium depletion. As 436L and 441 ferritic stainless steels contain higher Nb and Mo, thy present significantly higher resistance to high temperature urea corrosion rather than 439M. Moreover, due to the fine dispersion of inclusions in 436L and 441 stainless steels, the probability of nucleation and precipitation of chromium nitride on inclusions is also reduced, which is another cause for improving the resistance to high temperature urea corrosion of the relevant steels.