1. Why Green Leaf would Yellow
As days get shorter and temperature cool, the production of chlorophyll(叶绿素) slows down and eventually stop
Carotenoids(类胡萝卜素) always present in leaves
In fall and winter, the grow speed decrease and the tree would reabsorb the nutritions in the leaf
2. Wild Mushroom Grow
Mycelium（菌丝）can live in the soil, wood etc for a long periods of time without producing mushrooms
Ideal condition: right temperature, a certain amount of moisture and suitable organic matter
Cultivating: wild mushroom can harbor competitors and pathogens, you must sterile tools (无菌环境)
- Why still grow in wild: natural balance, huge quantity of spores
How mushroom spread their spores?
- Air current
- Rain drop
- Animal
3. 上火
Possible scientific explanation:
- Mouth ulcers could be caused by a variety of reasons
- Viral infection, stress, vitamin deficiencies
- Sore throat might be a sign of viral or bacterial infection
- Constipation can be due to a range of factors including diet
Sweet fruit
- High sugar intake, overtime, it can contribute to weight gain
- Oral health: sugar from the fruit can be utilized by bacteria to produce acids
- Nutrient Imbalance
4. Relationship between Distance and Depth of Field
Depth of field: range in a photo where the subject appear acceptably sharp
- Subjective measurement
Generally speaking
- The closer, the shallower
- The farther, the deeper
Simplified Math Model
$$
D O F=2 u^2 N c / f^2
$$
- U is the focus distance: the closer, the difference larger
- N is f number: large hole the light spread widely and diffusely
- C is the circle of confusion
- F is the focal length: magnify the blurring level
5. Dog Taste System
1700 taste buds compared to human 9000
More tuned to water
What’s tasty for dog
- Fatty foods
- Meat
- Sweet