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The 45 steel was sealing treated for various time in 6%(volume fraction)KH560 solution after the hot-dip aluminizing-anode oxidation. An Al-Al2O3-silane composite coating was formed on the surface of the 45 steel. The microstructure of composite coating was studied. The corrosion resistance of composite coating and its effect on the galvanic corrosion between the 45 steel and 30%(mass fraction)Cf/nylon6 composite were investigated. The results show that the silane coating effectively seals the cracks in Al2O3 coating, prevents the corrosive liquid from attacking the substrate. Hence, the corrosion resistance of the 45 steel is improved. Meanwhile, the good insulation property of the Al-Al2O3-silane composite coating can reduce the driving force of the galvanic corrosion between the 45 steel and 30%Cf/nylon6 composite, consequently, the galvanic corrosion resistance of 45 steel also is improved. After treated with the optimal KH560 treatment process for 5 min, the self-corrosion current density of the hot-dip aluminized 45 steel decreases by 3 orders of magnitude compared with that of the single hot-dip aluminized sample while the electrochemical impedance increases by 2 orders of magnitude, and the galvanic corrosion current density between the 45 steel and 30%Cf/nylon6 composite decreases by about 75%.

TiC-CoCrFeNi composite was fabricated by mechanical alloying and consequently vacuum hot pressing sintering, and the effects of milling time on the microstructure and mechanical properties of the composite was investigated. The results show that a single-phase solid solution with fcc structure is obtained after milled for 10h of Co, Cr, Fe and Ni powders. TiC and Cr7C3 structured carbides are formed and dispersed in the CoCrFeNi solid solution after hot pressing sintered at 1200℃ for 1h. Milling time has a significant effect on the size and amount of TiC and Cr7C3 structured carbides, which can affect the mechanical properties of the composite. When the milling time reaches 10h, the hardness and yield strength of the composite reach the maximum values of 671HV and 1440MPa, respectively, which is probably attributed to the dramatically increasing of nano-sized TiC in sintered bodies.

As a kind of fuel with low‐carbon emissions, hydrogen‐rich syngas has a large resource potential and is a promising alternative energy resource. A series of experiments in a constant volume combustion bomb are carried out to investigate the effects of turbulence and diffusional–thermal (DT) instability on a hydrogen‐rich syngas turbulent premixed flame. The flow field in the constant volume combustion bomb is calibrated, and the turbulent flow field's homogeneity and isotropy were investigated. The effects of different speeds of fan (1366–4273 rpm), hydrogen fractions (55%–95%), pressures (1.0–3.0 bar), and equivalence ratios (0.6–1.0) on the hydrogen‐rich syngas turbulent premixed flame are studied. According to the analyses, the flow field in the experimental device exhibits good homogeneous and isotropic characteristics. With the increase of turbulence intensity, equivalence ratio, hydrogen fraction, or pressure, the turbulent flame propagation speed increases gradually. As the hydrogen fraction increases or the equivalence ratio decreases, the effective Lewis number decreases, and the effect of DT instability on the flame increases. The research in this article is crucial for the clean and efficient utilization of hydrogen‐rich syngas and the design of related burners. [ABSTRACT FROM AUTHOR]

Herein, CoCrxCuFeMnNi (x = 0, 0.5, 1.0, 1.5, and 2.0, in molar ratio) high‐entropy alloys (HEAs) are prepared through vacuum hot‐pressing sintering. The influences of Cr content on the microstructure and the corrosion behavior in 3.5% NaCl solution are studied. The alloys are mainly composed of two face‐centered cubic (FCC) phases, namely, Cr–Co–Fe–Mn–Ni (or Co–Fe–Mn–Ni)‐rich FCC1 phase and Cu–Mn–Ni‐rich FCC2 phase. With the increase of Cr content, The FCC1‐phase area expands and the FCC2 phase area shrinks. In 3.5% NaCl solution, the corrosion current density (icorr) and average corrosion rate (Vcorr) of the HEAs decrease with the increase in Cr content. The icorr and Vcorr of Cr2.0 alloy are lower at 1.87 × 10−6A cm−2 and 0.02 mm year−1, respectively. The increase of transfer resistance (Rp) and decrease of relative thickness (CPE1−1) of the passivation film indicate that the more difficult it is for ions in the corrosive medium to pass through the capacitor layer, the better the corrosion resistance of the alloy. Improvement of the corrosion resistance is mainly due to the formation of denser Cr2O3 passivation film and reduction of the segregation degree of Cu in the FCC2 phase. [ABSTRACT FROM AUTHOR]

Halenia (Gentianaceae) originated from the mountain regions of East Asia, and diversified in America following long migrations via Beringia. While Halenia elliptica, one species of the genus in China, migrated toward high latitudes in China. Spur length of H. elliptica is highly variable. We examined the relationship between spur length and mating pattern along a latitude gradient. Field experiments were performed in two populations of H. elliptica, and we found that this species could produce seeds via both autonomous selfing and the aid of pollinators, suggesting a mixed mating system. In seven populations of H. elliptica along a latitudinal gradient, we found a trend of decrease in spur length with the increase of latitude. Based on molecular data from 11 microsatellite loci, we found that multilocus outcrossing rate decreased with the increase of latitude while the estimated inbreeding depression increased significantly, indicating that a high degree of inbreeding depression might have prevented evolution toward complete selfing in the high latitude populations with short spur length, and thus maintained mixed mating system of H. elliptica. Our results suggest that the mixed mating system of this species might be helpful in overcoming pollinator scarcity in newly colonized populations toward high latitudes after its origination in the mountain regions of China, and the decrease of spur length in the high latitude populations could result from reduced resource allocation to pollinator associated traits. [ABSTRACT FROM AUTHOR]

Pollination systems and associated floral traits generally differ between core and marginal populations of a species. However, such differences are rarely examined in plants with a mixed wind- and bumblebee-pollination system, and the role of wind pollination during range expansion in ambophilous plants remains unclear. We compared floral traits and the contributions of bumblebee and wind pollination in refugium and marginal populations of the ambophilous plant Aconitum gymnandrum. We found that most floral traits differed between the two populations, and those traits associated with the shift to wind pollination were pronounced in the marginal population. Bumblebee visitation rates varied significantly, but were generally low in the marginal population. Wind pollination occurred in both populations, and the efficiency was lower than that of bumblebee pollination. Two types of pollen grains, namely round and fusiform pollen, were transported to a stigma by bumblebees and wind, but fusiform pollen contributed to wind pollination to a larger degree, especially in the marginal population. Our results suggest that wind pollination was enhanced by pollen dimorphism in the marginal population of A. gymnandrum, and wind pollination may provide reproductive assurance when bumblebee activity is unpredictable during range expansion, indicating that ambophily is stable in this species and shift in pollination system could be common when plants colonize new habitats. [ABSTRACT FROM AUTHOR]