The spectral characteristics of different Chinese herbal medicines are quite different. Even the Chinese herbal medicines from the same place of origin, under the irradiation of near-infrared and mid-infrared spectra, will show different spectral characteristics because of the different chemical composition and organic matter of inorganic elements. Therefore, these characteristics can be used to identify the types and origins of Chinese herbal medicines.

202 1 Question A of the National Mathematical Modeling Competition for College Students has serious mistakes, misleading many students to simplify the reflective panel into a plane.

The key of this topic is to determine the geometric shape of each reflective panel. The geometric shape of each spherical triangular reflective panel is determined by the radius of the reference sphere and the coordinates of each main cable node.

Figure 4 in the title shows that the radius of the reference ball is R=300, and the attachment 1 shows the coordinates of the main cable nodes in the reference state (attachment 1 the corresponding reference ball is R=300.4). First, the reference ball R=300 shown in Figure 4 is substituted into the attachment 1, and the geometric shape of each reflection panel is obtained (at this time, R=300.4 in the attachment 1 is unknown).

It is found that the main cable node is not on the reference sphere, which leads many people to think that the geometry of each reflection panel can not be calculated, so the spherical triangle is simplified into a plane triangle, and the so-called reference sphere is an approximate sphere formed by splicing plates.

The setting in the stem of this question is inconsistent with the core setting in the annex, which is seriously wrong and misleading, leading many students to calculate the spherical triangular mirror as a plane triangular mirror. I hope that the National Mathematical Model Association will pay attention to this issue and give an account of everyone's hard work and achievements.