According to the national standards, all kinds of commercial timber are classified according to their defects, which are usually divided into one, two, three and four grades.

Generally, high-grade wood is selected for structure and decoration. For the timber used in the load-bearing structure, according to theprovisions of the Code for Design of Timber Structures, the timber is classified according to the stress requirements of the load-bearing structure, that is, it is divided into three grades, and the appropriate grade of timber should be selected according to the stress types of the components during design.

For example, in the selection of load-bearing timber structures, according to their load-bearing characteristics, the first-class timber is used for tensile or flexural members; Second-class materials are used for bending or compression bending members; Third-grade materials are used for compression members and secondary bending members.

What is the sign on the back of the icon solid wood floor?

The icon solid wood floor has the logo, model and the number of revolutions of the wear-resistant layer on the back.

Can I fill in the implementation standard of wooden handicrafts at will?

Don’t scribble.

Because the implementation standard number is an important identification, and each standard has its specificpurpose and scope of application, if the implementation standard number is scribbled, it may lead to improper use or misuse, thus causing unnecessary risks and accidents.

Therefore, in theprocess of using standards, we should accurately check the implementation standard number and ensure the correct use of standards according to the requirements of standards.

What colors are the land, ocean and mountains on the globe?

Blue is the ocean (including all waters), green is theplain, yellow is theplateau, and white is the snow. Altitude is used to indicate the ups and downs of the mountain range.

According toproduct materials and functions, there arepaper globes,plastic globes, resin globes, stone globes, metal globes, solid wood globes, magnetic levitation globes, classical craft globes, electronicpoint reading voice globes, voice globes and video globes.

The globe is a necessary teaching aid in geography teaching inprimary and secondary schools. It is often used to explain the following contents:

First, the earth: understand the causes of the alternation of day and night and the change of seasons; Analyze the influence of the earth’s movement on the climate.

Second, the distribution characteristics of longitude and latitude lines: the length in the shape direction; Know the function of latitude and longitude net.

Third, the world’s land and sea: know thepositional relationshipbetween the seven continents and the four oceans and the latitude zone where they are located; Know theposition of sixplates; Understand the main topographic areas and the topographic features of major continents; Find the location of the date line.