Using the seasonal FGM(1,1) model to predict the air quality indicators in Xingtai and Handan

L F Wu1, Nu Li2, Ting Zhao2

  • 1College of Economics and Management, Hebei University of Engineering, Handan, 056038, China. wlf6666@126.com.

Related Concept Videos

Indicators02:39

Indicators

Certain organic substances change color in dilute solution when the hydronium ion concentration reaches a particular value. For example, phenolphthalein is a colorless substance in any aqueous solution with a hydronium ion concentration greater than 5.0 × 10−9 M (pH < 8.3). In more basic solutions where the hydronium ion concentration is less than 5.0 × 10−9 M (pH > 8.3), it is red or pink. Substances such as phenolphthalein, which can be used to determine the pH of a solution, are...
60.4K
Seasoning of Wood01:15

Seasoning of Wood

Seasoning of wood is a crucial process aimed at reducing and stabilizing the moisture content within the wood to prevent future shrinkage, structural damage, or aesthetic issues once the wood is used in construction. Wood naturally swells when it absorbs moisture and contracts as it dries.
Achieving equilibrium moisture content is the goal of seasoning; this is the point where the wood's moisture content stabilizes to align with the moisture levels of the surrounding environment. Proper...
499
Biological Clocks and Seasonal Responses02:45

Biological Clocks and Seasonal Responses

The circadian—or biological—clock is an intrinsic, timekeeping, molecular mechanism that allows plants to coordinate physiological activities over 24-hour cycles called circadian rhythms. Photoperiodism is a collective term for the biological responses of plants to variations in the relative lengths of dark and light periods. The period of light-exposure is called the photoperiod.
41.7K
Predicting Molecular Geometry02:27

Predicting Molecular Geometry

VSEPR Theory for Determination of Electron Pair Geometries
45.7K