Abstract: A gene PpHSP21 with black spot disease resistance is isolated from Pyrus pyrifolia. A nucleotide sequence of the gene PpHSP21 is shown in SEQ ID NO. 1. An amino acid sequence of an encoded protein of the PpHSP21 gene is shown in SEQ ID NO. 2. By constructing the plant overexpression vector and silencing vector of the gene PpHSP21, the gene PpHSP21 is introduced into the plant by the Agrobacterium-mediated genetic transformation method, so that the gene PpHSP21 is able to be overexpressed in the plants, thereby significantly improving black spot disease resistance in plants. The discovery and identification of the gene PpHSP21 provide new genetic resources for stress resistance molecular design and breeding in plants, and to provide new genetic resources for the implementation of green agriculture. The development and utilization of the genetic resources is conducive to reducing agricultural production costs and achieving environmental friendliness.

Abstract: The present disclosure relates to a micron silver particle-reinforced 316L stainless steel matrix composite, including a 316L stainless steel matrix and silver particles uniformly distributed in the 316L stainless steel matrix. The silver particles have a weight 1% to 5% of the total weight of the composite; and the composite has a density of 7.9 g/cm3 to 8.2 g/cm3 and a relative density of more than 98%. The composite is prepared by the following method: mixing raw materials of a spherical silver powder and a spherical 316L stainless steel powder; subjecting a resulting mixture to mechanical ball milling to obtain a mixed powder; sieving the mixed powder and adding a resulting powder to a powder cylinder of an SLM forming machine; and charging an inert protective gas for printing to obtain the composite.

Abstract: The present disclosure relates to a micron silver particle-reinforced 316L stainless steel matrix composite, including a 316L stainless steel matrix and silver particles uniformly distributed in the 316L stainless steel matrix. The silver particles have a weight 1% to 5% of the total weight of the composite; and the composite has a density of 7.9 g/cm3 to 8.2 g/cm3 and a relative density of more than 98%. The composite is prepared by the following method: mixing raw materials of a spherical silver powder and a spherical 316L stainless steel powder; subjecting a resulting mixture to mechanical ball milling to obtain a mixed powder; sieving the mixed powder and adding a resulting powder to a powder cylinder of an SLM forming machine; and charging an inert protective gas for printing to obtain the composite.