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To explore a new formulation system of diamond bit matrix, three kinds of Fe-based pre-alloyed powder with low liquid phase content were utilized for the matrix fabrication of impregnated diamond bit (IDB). To this end, the D-optimal mixture design method was employed for the design of the experiment scheme which contained 16 groups of samples. The samples were fabricated under the same hot pressing sintering conditions, then tests on hardness, bending strength, and relative density were conducted. The results were analyzed by regression analysis, and so were the interrelations and interactions of formula components on matrix properties. Meanwhile, the fracture surface of samples after the bending strength test was observed by SEM. It was found that FAM1020 and FAM2120 have a positive effect on the bending strength of metal matrix composite. Besides, FAM2120 has a positive effect on the hardness of the matrix, but a negative effect on the bending strength of the diamond matrix composite. The interaction among the three powders can improve the performance of the matrix. According to the result, the Fe-based pre-alloyed bit matrix with low liquid phase content can meet the requirements of the diamond bit matrix. Based on this exploration experiment, an optimal formulation is concluded as 50 wt % X1, 30 wt % X2, 20 wt % X3.

A mammalian plasma membrane is a structure on which several layers of complexity are built. The first order of complexity comes from the heterogeneity of lipid-ordered domains. Gangliosides in concert with cholesterol are preferentially packed on the outer leaflet and form lipid-ordered domains, commonly known as lipid rafts. The formation and dynamics of these domains impact nearly all membrane protein functions and are an intensely studied topic. However, tools suited for lipid domain alteration are extremely limited. Currently, methyl-β-cyclodextrin (MβCD) appears to be the most common way to disrupt lipid domains, which is believed to operate via cholesterol extraction. This significantly limits our ability in membrane biophysics research. Previously, we found that N-(3-oxo-dodecanoyl) homoserine lactone (3oc), a small signaling chemical produced by Pseudomonas aeruginosa, is highly efficient in altering lipid-ordered domains. In this study, 3oc was compared with MβCD in a series of biochemical, biophysical, and cell biological analyses. Per molarity, 3oc is more efficient than MβCD in domain alteration and appears to better retain membrane lipids after treatment. This finding will provide an essential reagent in membrane biophysics research.

An iron-rich pre-alloyed powder was selected out, and the pre-alloying degree of matrix materials and the sintering temperature were considered to investigate the effect of the Fe-based pre-alloyed powder on the microstructure and holding strength of impregnated diamond bit matrix. And relative density and bending strength of the specimens were measured, and then the resulting fracture surfaces were analyzed using scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS). The results showed that the relative density, bending strength and plasticity of matrix materials are increased with the sintering temperature and the pre-alloying degree. The influence of the pre-alloying degree on them is more significant than that of the sintering temperature within the experimental parameters. Besides, Fe-based matrices have thermal corrosion effect on diamonds at high temperature sintering process. And the rate of diamond graphitization has a greatly increase with the sintering temperature changes from 900 °C to 1020 °C and the holding strength decreases. A low pre-alloying degree accelerates the rate of diamond graphitization. But an adequate pre-alloying degree of Fe-based matrix materials is conducive to improve the wettability of the matrix to diamonds, alleviate the diamond graphitization, reduce the diamonds' thermal damage and improve the holding strength. Besides, it can also greatly reduce the sintering temperature and broaden the sintering temperature range. In a word, it is feasible and reasonable that Fe-based pre-alloyed powders replace Fe elemental powders to fabricate impregnated diamond bits. And it has a good economic value and broad application prospect.

Stay ring is the foundation-bearing components of Francis turbine-generator unit and an important part of the flow components. It should not only have enough strength and rigidity, but also excellent hydraulic performance. As the unit capacity of Baihetan Hydropower Station reaches 1000MW, the priority should be on safety. After completing the turbine model acceptance test of Baihetan Hydropower Station Left Bank, it was found that the local stress at the tail of stay vanes was too high in the re-check analysis of the rigidity and strength of the stay ring. In order to ensure the stay ring has sufficient safety margin, the stay vane should be strengthened in design. After stay vane strengthened, the rigidity and strength of the stay ring are improved obviously. In this paper, the strengthen design, stiffness and strength analysis and model verification of turbine stay vane for Baihetan Hydropower Station Left Bank are analyzed and explained.

Molten inorganic salts containing solid nanoparticles with a stable and uniform dispersion have attracted great attention as efficient heat transfer and storage materials1,2 and for catalysis for chemical reactions3-5. Compared with those in aqueous suspensions6,7, electrophoretic deposition and electro-codeposition in molten inorganic salts containing nanoparticles, have not been reported in the literature. Here we report the possibility of electrophoretic deposition of nanoparticles and electro-codeposition of nanoparticles and metal ions in high-temperature molten salts. In molten fluorides and chlorides, a cell voltage of 1.2-1.5 V below the decomposition voltage of the electrolytes, was applied to perform the electrophoretic deposition of nanoparticles (e.g., TiB2 and ZrB2), resulting in compact and adhesive coatings. In molten chlorides containing TiB2 nanoparticles, with the introduction of electroactive specimen MoO3, the electro-codeposition of TiB2 nanoparticles and Mo-containing ions has been achieved to yield a dense and adhesive Mo/TiB2 nanocomposite coating with homogeneous distribution of Mo and TiB2, without the assistance of stirring of molten salts. These findings should present opportunities to synthesize various coatings and films via the proposed processes.

Electrophoretic deposition is a type of significant method for preparing coatings and films, which has been widely investigated in aqueous and organic suspensions. However, electrophoretic deposition in molten inorganic salts containing nanoparticles, have not been reported in the literature. Here we report the possibility of electrophoretic deposition of nanoparticles in molten inorganic salts. In two types of molten systems (fluorides (980 °C) and chlorides (710 °C)), the electrophoretic deposition of diboride nanoparticles (e.g., TiB2 and ZrB2) on different cathode substrates under cell voltages of 1.2–1.5 V (below the decomposition voltage of the electrolytes), has been successfully demonstrated, resulting in a compact TiB2 coating with hardness of 43.7 ± 2.8 GPa and a ZrB2 coating with a nanocrystal structure. Besides diboride nanoparticles, this proposed process should be applicable for a wider range of nanoparticles to produce more types of coatings and films.