4results about How to "The preparation method is reasonable" patented technology

The application provides an edible active coating for preventing dry consumption under an ultralow temperature condition and a preparation method, and belongs to the technical field of active packaging. The application combines double-layer coatings, inhibits free radical oxidation generated by freezing through an inner antioxidant, and effectively locks water and blocks external oxygen permeation through the synergistic effect of an outer high-barrier structure, thereby significantly improving the freezing preservation effect of food, and the raw materials are natural and safe, the preparation method is reasonable, and the application has good practical application value. The application solves the problems of poor effects of edible freezing protection coatings suitable for extremely cold environments in the prior art.

The application discloses a kind of buried copper block circuit board and its manufacturing method, the manufacturing method includes: the two outer layers of core plate are copper foil layer, and window position A is provided on the non-line area of one outer layer;Core plate is double-sided inner layer pattern production, to make inner layer circuit pattern and pad on the two outer layers of core plate respectively, and make a plurality of flow blockings on one outer layer of core plate, which are surrounded outside window position A;The insulating layer is covered on the two outer layers of core plate, and window position B is provided on the insulating layer adjacent to flow blocking, which is opposite to window position A;Based on window position, insulating layer and core plate are windowed;After the copper block gap with rough surface is placed in window, it is compressed and handled, and in the process of compression, the flow of colloid in window is controlled by flow blocking, so that copper block is firmly combined with insulating layer and core plate together.The manufacturing method is simple and reasonable, easy to implement, the reliability and stability of the obtained circuit board product are high, and the market demand is met.

The application provides N-(3,5,6-trimethylpyrazine-2-methylene)-huperzine A and a synthetic method and application thereof. A structural formula is as follows: a preparation method thereof comprises the following steps: (1) carrying out bromination reaction on tetramethylpyrazine to obtain 2-bromomethyl-3,5,6-trimethylpyrazine; (2) carrying out condensation reaction on huperzine A and 2-bromomethyl-3,5,6-trimethylpyrazine to obtain N-(3,5,6-trimethylpyrazine-2-methylene)-huperzine A. The compound not only has acetylcholinesterase inhibition effect, but also can prevent brain nerve tissue aging and cell apoptosis by eliminating ROS and free radicals and resisting oxidative damage, so as to intervene in the development of Alzheimer's disease.

The application discloses a low-temperature high-strength neutral soldering paste and a manufacturing method thereof. The soldering paste has the following raw material formula in percentage by weight: 87-92% of tin-based alloy powder, 3.5-5% of activating agent, 0.5-1.2% of reinforcing agent, 0.5-2% of thixotropic agent and 2-6% of solvent. The alloy components in the tin-based alloy powder and their percentage by weight are as follows: 90-95% of Sn, 2-5% of Ag, 0.2-1% of Cu and 2-6% of Bi. The activating agent is composed of dimethylol propionic acid, sodium phosphate and ammonium fluoroborate according to a weight ratio of 1: (0.1-0.4): (1.5-2). The reinforcing agent comprises reinforcing alumina particles subjected to metallization treatment, and the reinforcing alumina particles have a nanoscale particle size. The soldering paste has the characteristics of low welding temperature, good wettability, improved solder joint shear strength, neutral no post-welding corrosion and the like, and is suitable for precise welding scenes.