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GH2132 alloy， as one of the representative materials of high-temperature alloys based on Fe-25Ni-15Cr，has become a widely used high-temperature material below 650 ℃ due to its excellent comprehensive properties. At present，the research on GH2132 alloy mainly focuses on three aspects： solid solution heat treatment，solid solution + aging heat treatment，and direct aging heat treatment. This article summarizes recent research on the alloy in these three aspects and analyzes the impact of heat treatment processes on microstructure and properties. During the solid solution treatment process of GH2132 alloy，attention should be paid to the effect of the dissolution of Laves and M3B2 phases on grain size to prevent grain coarsening. The alloy after solid solution exhibits the characteristics of low strength and high plasticity. The formulation of aging treatment process needs to be combined with solid solution treatment process，taking into account the influence of coupling effect and preventing occurrence γ′ → η transform and reduce the reinforcement effect. The microstructure of GH2132 alloy is sensitive to deformation，and the larger the deformation，the lower the aging temperature or shorter the aging time should be chosen.

A modular metabolic engineering for Escherichia coli was designed for efficient production of β-nicotinamide mononucleotide (β-NMN). First, eight enzymes involved in the shunt metabolic pathways of nicotinamide (NAM) and β-NMN were inactivated to reduce the additional consumption of precursors and products by chassis cells. Second, by introducing BcNaiP, BmPnuC, 5-phosphoribosyl-1-pyrophosphate synthetase (Prs) and nicotinamide phosphoribosyl transferase (Nampt) and deleting the regulatory protein PurR, an engineered strain N12’ was obtained, which could accumulate 0.34 g/L β-NMN in shake-flask fermentation. Then, we found that the Nampt enzyme from Comamonadaceae bacterium had higher activity and caused less burden on the chassis cells. By further strengthening the expression levels of BmPnuC and Prs, the β-NMN titer of the engineered strain N18 was increased to 1.36 g/L in shake-flask fermentation. Finally, after fed-batch fermentation for 38 h, the β-NMN titer reached 10.2 g/L, and the molar conversion rate of NAM to β-NMN was 74.5%. This engineered strain has the advantages of clear genetic background, no nutritional defects, and no need for induction and therefore, has a good prospect for industrial application.