4 results about "Spectrophotometry" patented technology

Provided are film-coated powders, coating compositions and coated materials that give off vivid and deep colors. The film-coated powders have a coating film on the surface of substrate particles, and has spectrophotometric characteristic in that, when the ratio of the length at 400 nm between 380 and 780 nm on measuring the reflection spectrum from the vertical reflection light of the film-coated powder (wavelength definition width L) to the height of the reflectance 100% in the vertical axis (reflectance definition width R), L/R is 5/2, then the ratio of the peak height (H) to the half-value width (W), H/W is at least 1.

Provided is a method for preparing a two-dimensional metallic photonic crystal structure in large area through femtosecond laser direct writing. The invention provides a method and experiment device for preparing the periodically-distributed two-dimensional photonic crystal structure with the feature size being the sub-micron dimension in one step in the large area by focusing identical-wavelength double-pulse femtosecond laser on the surface of metal through a plano-convex cylindrical lens, and the identical-wavelength double-pulse femtosecond laser is obtained based on the spectrophotometry of birefringent crystals and has the features of collinear transmission, cross polarization and picosecond time delay. Two-dimensional periodic structure patterns can be effectively regulated and controlled by changing the energy and the number of pulses of input laser, the thicknesses and the azimuth angles of the birefringent crystals and the like. Through the combined design of different linear polarization directions and the variable time delay feature of two femtosecond laser pulses and focusing of the cylindrical lens, preparation of the two-dimensional metallic photonic crystal structure within the large area is achieved conveniently and quickly. The novel preparation method adopting the double-pulse femtosecond laser with cross polarization and variable time delay has potential important applications in the field of material micro-nano processing and preparation.

The invention discloses a method for measuring the content of L-carnitine in infant foods and dairy products by spectrophotometry. According to the research, by utilizing a principle that free L-carnitine in the products can react with acetylcoenzyme to generate acetylcarnitine and free coenzyme, the amount of yellow substances generated by reaction between the free coenzyme and a color developingsolution is detected through the spectrophotometry, thereby indirectly calculating the content of the L-carnitine in a sample. An experimental result shows that the addition amount of an acetylcoenzyme solution is 80 [mu] L, the addition amount of a carnitine acetyltransferase solution is 100 [mu] L, the reaction time is 5 minutes, and accurate, economic and rapid detection requirements can be met.