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The SiC coating prepared on graphite substrate can effectively solve the corrosion and powder loss problems of graphite material in environments with high temperature and corrosive gas. In this paper, a SiC coating was prepared on the surface of graphite substrate. The deposition process parameters were adjusted and optimized to realize rapid manufacturing of high - performance SiC coating with the aim of providing theoretical basis and technical support for SiC coating’ application on the surface of graphite substrate. An industrial - grade chemical vapor deposition equipment was employed to prepare the silicon carbide coating on the surface of graphite substrates using methyl trichlorosilane (MTS) and H2 as raw materials. The effects of furnace pressure and sample position on the microstructure and thermal fatigue resistance of the coating were studied by analysis and testing methods such as scanning electron microscopy, X - ray diffractometer and vacuum thermal cycling. Results showed that when the furnace pressure was 2.0 kPa, a high - purity silicon carbide coating with single grain growth orientation could be prepared. As the furnace pressure increased, the deposition rate and thermal fatigue resistance of the coating both showed a non - monotonic change of first rising, then falling and then rising again. When the furnace pressure was 2.0 kPa, the silicon carbide coating had the highest deposition rate and the best thermal fatigue resistance. The coatings prepared with different sample positions were all pure SiC coatings, and the closer the substrate suspension position to the air distribution plate, the faster the coating deposition rate was and the better thermal fatigue resistance the coating showed. When the furnace pressure was 2.0 kPa and the sample position was 300 mm, a SiC coating with good thermal fatigue resistance could be quickly prepared.

Our previous study has demonstrated that sulfated Chinese yam polysaccharide (SCYP) can improve immunomodulatory activity in Raw 264.7 cells. However, its anti‐inflammatory is little known. In this study, the anti‐inflammatory effects of SCYP were systematically investigated via the Lipopolysaccharides (LPS)‐induced Raw264.7 cell model, Caco‐2/Raw264.7 co‐culture system, and acute inflammation mice model. The results suggested SCYP promoted the cell proliferation and have no toxicity in Raw264.7 and Caco‐2 cells at the concentration of 200 µg/mL. Moreover, when treated with SCYP, the production of pro‐inflammatory cytokines (interleukin [IL]‐1β, IL‐6, and tumor necrosis factor‐α) reduced significantly in Raw264.7 via the MAPK/NF‐κB pathway. In the Caco‐2/Raw264.7 co‐cultured system, SCYP could regulate inflammation reaction by improving intestinal barrier, which might prevent systemic inflammation. Further, systemic inflammation was alleviated by SCYP in LPS‐induced acute inflammation mice through MAPK/NF‐κB pathway. Practical Application: These results supported that SCYP may be used as an anti‐inflammation agent in the functional food field. [ABSTRACT FROM AUTHOR]

Similitude laws can be used to extrapolate the vibration characteristic of a small, inexpensive, and easily tested model into structural behavior for the full-size prototype. In this article, a systematic similitude approach is proposed to predict the natural frequency, mode shape, and vibration response of composite laminated plates. The emphasis of this article is to predict the vibration characteristic of composite laminated plates in an effective and convenient way. Sensitivity analysis (SA) is introduced to improve the prediction accuracy of natural frequency. For distortion similarity, the prediction accuracy is improved close to 5%. Modal assurance criterion (MAC) measures the consistency of mode shapes of the full-size prototype and scaled models. The influence of stacking sequence on mode consistency is investigated. Similitude based on virtual mode and statistical energy (SVMSE) is proposed to extrapolate the transient response of the prototype to simulate the shock environment, such as satellite–rocket separation, etc. In conclusion, the prediction accuracy of natural frequency, mode consistency, and response coincidence are considered comprehensively to extrapolate the vibration characteristic of the full-size laminated plates. [ABSTRACT FROM AUTHOR]

In order to increase the application of CO2 in cementitious materials and to develop new additives for cement-based materials, the effect of lithium carbonate (Li2CO3) on the properties of Portland cement (PC) paste was investigated. The hydration heat of fresh paste was tested and the hydration products were characterized using XRD, TG–DTA, SEM and MIP. The results showed that both the initial and final setting time of the PC paste was prolonged with increasing Li2CO3 content. While, the compressive strength of the hardened PC paste at 1 day, 7 days and 28 days increased initially and then decreased. When the content of Li2CO3 was 0.09wt%, the initial and final setting time was increased by 19.8% and 27.7%, and the compressive strength at the age of 1 day, 7 days and 28 days was increased by 47.6%, 21.2% and 14.0%, respectively. Hydration heat, TG–DTA, XRD, SEM, pore structure and other tests showed that Li2CO3 promoted the formation of AFt, and prolonged the arrival time of hydrated calcium silicate peak, but increased the formation of hydrated calcium silicate. Especially when the Li2CO3 content was below 0.09wt%, the pore structure was also optimized. Based on the above results, when the content of Li2CO3 is not greater than 0.09wt%, not only the setting of the Portland cement paste can be retarded, but also the early strength can be enhanced. This can provide a good reference for the use of Li2CO3 in the preparation of new Portland cement-based material admixtures. [ABSTRACT FROM AUTHOR]