Knowledge about spring

The knowledge about springs is as follows:

1, at midnight, Niu Jiao women get up. Planting trees in the Ming dynasty is the vernal equinox, which will usher in the vernal equinox and solar terms. After eating the vernal equinox, the day becomes a little longer. After the vernal equinox, the direct point of the sun is in the northern hemisphere, and it gradually moves northward to the northern hemisphere. The days are getting longer and the nights are getting shorter and shorter.

2. The vernal equinox is one of the earliest solar terms in ancient China. As early as 3000 years ago, Zhou was on the vernal equinox, and the ceremony of offering sacrifices to heaven and sun continued until the Qing Dynasty, which was exclusively enjoyed by the royal family. In ancient times, it was also called the equinox of Japan and China, the equinox of day and night, and the mid-spring moon. On this day, the sun shines directly at the equator of the earth day and night.

3. Spring, also known as spring, is the first season of the year. March, April and May of the solar calendar are in the northern hemisphere, and November begins in the southern hemisphere. For example, in Australia, the climate is warm and mild in spring, and it seldom rains in most parts of China. Everything is animistic, the climate is changeable, and it is warm and cold at first.

4. Many people are allergic to pollen in spring. Everyone thinks that flowers in spring are easy to cause pollen allergy, but this is actually a misunderstanding. Zhu, director of the Allergy Department of tongji hospital affiliated to Tongji Medical College, Huazhong University of Science and Technology, said that brightly colored flowers such as peach blossoms and rape blossoms are not easy to cause allergies. These flowers are insect-borne flowers.

Their pollen grains are big, heavy and sticky, so they can't float in the air. They can only attract bees for pollination, and only a few people are allergic to them. The pollen of trees, grasses and small wildflowers is called wind-borne flowers, which is the main cause of pollen allergy. Some pollen is too small to be seen by the naked eye, very light and rich. When the wind blows, a large number of pollen floats in the air, and people are easily sensitized after contact and inhalation.

5. Rain: It began to rain and gradually increased. The rainy season means that it begins to rain and the rainfall gradually increases. In the Yellow River valley, the birthplace of the 24 solar terms, it was cold before the rain, but it was snowing and raining unpleasantly. After the rain, the temperature can generally rise above 0℃, with less snow and more rain. However, in the warm southern region, even in the dead of winter, rainfall is not uncommon.