Ti
3
SiC
2
/SiC composites exhibit distinctive physical and chemical properties, which include unique-layered structures, excellent tribological properties, high thermal and electrical conductivity, ...etc. These properties bestow it significant potential applications. In recent years, there has been a notable advancement on the study of Ti
3
SiC
2
/SiC composites. Therefore, it is necessary to arrange a comprehensive overview of their research progress. In this review, the synthesis methods of Ti
3
SiC
2
/SiC composites are summarized, and these methods include sintering, molten salt, chemical vapor deposition, electrophoretic deposition, and other solid–liquid permeation synthesis methods. In addition, the different physical forms formed by Ti
3
SiC
2
/SiC composites are reported on their properties and important applications, specifically friction devices, microwave shielding and absorbing materials, materials for high-temperature applications, and other uses such as coating treatments. By exploring these innovative approaches, we can gain a better understanding on the synthesis and applications of Ti
3
SiC
2
/SiC composites.
Carbide-derived carbon (CDC) coatings with dimple (CDC@GSiC coating) and loosely dispersive particles structures (CDC@RBSiC coating) were prepared on two kinds of SiC substrates by using chlorination ...at 1,000 °C in a 5 vol.% Cl
2
–Ar gas. Microstructural effect makes the two CDC coatings exhibit different frictional behavior in ambient pressure and in vacuum. For the CDC@RBSiC coating, the friction coefficient was from 0.08 to 0.12 at ambient pressure and is sensitive to evacuation from ambient pressure to 10
3
Pa while it was as high as 0.42 up to a pressure of 10
−4
Pa. Progressive evacuation does not vary the friction coefficient of the CDC@GSiC coating up to 10
−3
Pa. The wear of the CDC@GSiC coating was low with a maximum depth of 8 μm and much lower than that of the CDC@RBSiC coating (70 μm). The dimples on the surface and pores in the CDC@GSiC coating are reservoirs for ion liquid (IL), and the IL impregnated CDC@GSiC coating shows very low friction and wear at ambient pressure and in vacuum.
The ancestors of Gossypium arboreum and Gossypium herbaceum provided the A subgenome for the modern cultivated allotetraploid cotton. Here, we upgraded the G. arboreum genome assembly by integrating ...different technologies. We resequenced 243 G. arboreum and G. herbaceum accessions to generate a map of genome variations and found that they are equally diverged from Gossypium raimondii. Independent analysis suggested that Chinese G. arboreum originated in South China and was subsequently introduced to the Yangtze and Yellow River regions. Most accessions with domestication-related traits experienced geographic isolation. Genome-wide association study (GWAS) identified 98 significant peak associations for 11 agronomically important traits in G. arboreum. A nonsynonymous substitution (cysteine-to-arginine substitution) of GaKASIII seems to confer substantial fatty acid composition (C16:0 and C16:1) changes in cotton seeds. Resistance to fusarium wilt disease is associated with activation of GaGSTF9 expression. Our work represents a major step toward understanding the evolution of the A genome of cotton.
Ti
SiC
-PbO-Ag composites (TSC-PA) were successfully prepared using the spark plasma sintering (SPS) technique. The ingredient and morphology of the as-synthesized composites were elaborately ...investigated. The tribological properties of the TSC-PA pin sliding against Inconel 718 alloys disk at room temperature (RT) to 800 °C were examined in air. The wear mechanisms were argued elaborately. The results showed that the TSC-PA was mainly composed of Ti
SiC
, Pb, and Ag. The average friction coefficient of TSC-PA gradually decreased from 0.72 (RT) to 0.3 (800 °C), with the temperature increasing from RT to 800 °C. The wear rate of TSC-PA showed a decreasing trend, with the temperature rising from RT to 800 °C. The wear rate of Inconel 718 exhibited positive wear at RT and negative wear at elevated temperatures. The tribological property of TSC-PA was related to the tribo-chemistry, and the abrasive and adhesive wear.
Ti
SiC
/CaF
composites were prepared by the spark plasma sintering (SPS) process. Both the microstructure of Ti
SiC
/CaF
and the influence of test temperature on the tribological behavior of the Ti
...SiC
/CaF
composites were investigated. The synergistic effect of friction and oxidation was evaluated by analyzing the worn surface morphology. The results showed that Ti
SiC
/CaF
were still brittle materials after adding CaF
, which was in agreement with Ti
SiC
. The hardness, relative density, flexural strength and compressive strength of the Ti
SiC
/CaF
composites were slightly lower than those of Ti
SiC
, and the addition of CaF
decreased the decomposition temperature of Ti
SiC
from 1350 to 1300 °C. Simultaneously, as the temperature of the test increased, the friction coefficient of Ti
SiC
/CaF
showed a downward trend (from 0.81 to 0.34), and its the wear rate was insensitive.
Abstract The Ti 3 SiC 2 /Cu composites were synthesized by spark plasma sintering (SPS) at 950°C, 1000°C, and 1050°C, and the as‐formed composites were oxidized at 700°C, 800°C, and 900°C. The ...effects of the sintering temperature and the oxidation temperature on the anti‐oxidation of the composites at high temperatures were explored. The samples were characterized by X‐ray diffraction, optical microscopy, scanning electron microscopy, energy dispersive spectroscopy, and X‐ray photoelectron spectroscope. The results indicated that the sintering temperature significantly improved the oxidation resistance of the composites. With the increase of the sintering temperature, the weight gain of the oxidation of the composites decreased and the optimum sintering temperature was 1050°C. At an identical sintering temperature, with the increase of the oxidation temperature, the weight gain of the oxidation of the composites first decreased and then it increased. Thus, when the oxidation temperature was 800°C, the composites exhibited an excellent oxidation resistance (oxidation weight gain: .0042 × 10 −5 g/mm 2 ). The anti‐oxidation behavior of the composites benefited by the formation of an oxide layer. The oxide layer was composed by TiO 2 , CuO, and amorphous SiO 2 .
•Astragalus membranaceus-Curcuma wenyujin showed a significant effect on inhibiting tumor growth and metastasis of colon cancer in vivo, especially at the proportion of 2:1.•UPLC-Q/TOF-MS ...metabolomics was used to explore the metabolites in the serum of colon cancer tumor-bearing mice.•Twenty-three endogenous metabolites were tentatively identified as the colon cancer biomarkers and eight metabolic pathways were found disordered in the serum of colon cancer tumor-bearing mice.•Astragalus membranaceus-Curcuma wenyujin showed partially callback effect on the CC-related biomarkers.•The correlation result of R language analysis showed that hypoxanthine, xanthosine, 7-methylxanthine, 11,12-epoxyeicosatrienoic acid, L-aspartic acid, all-trans-retinoic acid and dihomo-γ-linolenic acid have a significant correlation with the occurrence of colon cancer, and they can be used as a clinical potential diagnostic indexs.
Metabolomics, an important part of systems biology, can reveal the complex pathogenesis of many diseases and mechanism of Chinese materia medica (CMM). Astragalus membranaceus-Curcuma wenyujin (AC) was a classic drug pair that has a good clinical effect on gastrointestinal inflammation and many tumors. Our previous research proved that AC can inhibit tumor growth and metastasis especially the colorectal cancer (CRC), also promote the normalization of tumor blood vessels, but its optimal ratio and the specific mechanism is still not clear. In this study, colon cancer mice of orthotopic transplantion model was used to screen the best proportion, UPLC-Q-TOF/MS metabolomics analysis method was established to explore the pathogenesis of colon cancer and the molecular mechanism of AC. The correlation analysis of metabolite changes and tumor growth was analyzed by R language. The result showed that AC at the ratio of 2:1 showed the best effect on inhibiting tumor growth, also the liver and spleen metastasis rate. A total of 23 potential biomarkers were detected in the serum of colon cancer mice by the analysis of Progenesis QI (Version 2.4) software. Among this, 11 metabolites including purines, steroids, phytosphingosine and l-palmitoylcarnitine were up-regulated in CC mice, while 12 metabolites like amino acids, deoxyribose and dihydrobiopterin were down-regulated in CC mice. After the treatment of AC for 15 days, 8 biomarkers were up-regulated, and 9 biomarkers down-regulated. Especially, AC at the ratio of 2:1 showed a significant callback effect on metabolic biomarkers, such as hypoxanthine, xanthosine, 7-methylxanthine, all-trans-retinoic acid, dihomo-γ-linolenic acid. 8 metabolic pathways: Aminoacyl-tRNA biosynthesis, Nicotinate and nicotinamide metabolism, Phenylalanine, tyrosine and tryptophan biosynthesis, Valine, leucine and isoleucine biosynthesis, Phenylalanine metabolism, Caffeine metabolism, Retinol metabolism, Alanine, aspartate and glutamate metabolism were selected as the model group disturbed metabolic pathways after the enrichment of MetaboAnalyst 4.0 online analysis software. And compared with the model group, Valine, leucine and isoleucine biosynthesis, Aminoacyl-tRNA biosynthesis, Caffeine metabolism pathway and Retinol metabolism pathways were altered after the intervention of AC. The correlation analysis results showed that various endogenous metabolites in serum have a strong correlation with tumor weight, such as hypoxanthine, which provides a basis for the selection of clinical markers. The results showed that AC can partially regulate metabolic disorder of CC mice by reversing the changes of metabolites, so as to inhibit the growth and metastasis of colon cancer, especially at the ratio of 2:1. These findings can provide a scientific basis for exploring the diagnostic biomarkers of colon cancer, and for clinical application of AC in the treatment of CRC program.
Abstract The corrosion behaviors of Ti 3 SiC 2 /Cu composites synthesized by spark plasma sintering technique were investigated at 900°C in three molten salts including NaCl, Na 2 SO 4 , and Na 2 CO ...3 , and the related corrosion mechanism was discussed. The morphology and composition of the composites after corrosion were characterized by scanning electron microscopy and X‐ray photoelectron spectroscopy. The results indicated that the weight gain per unit surface area of the composites was negative in molten Na 2 CO 3 , while it was positive and relatively small in molten NaCl and Na 2 SO 4 . The high weight loss of the composites in molten Na 2 CO 3 was owing to that in molten Na 2 CO 3 , an oxidation layer of the composites was dissolved, and oxygen diffused through the layer to corrode the substrate inside. Thus, in the molten Na 2 CO 3 , the composites exhibited a worse corrosion resistance. However, in molten NaCl and Na 2 SO 4 , an oxidation layer containing SiO 2 and TiO 2 was formed on the surface of the composites, inhibiting its further corrosion. Conclusively, the composites showed better corrosion resistance in molten NaCl and Na 2 SO 4 .
PDF
