What is the sound barrier? What is the specific effect
In the way of expression of their feelings deeply infected .This real emotional expression, so that writing transmission of a strong appeal, I also cried. I played for this essay excellent - in accordance with the general requirements of writing , Although it is not really good.I reason to give this essay excellent, because this essay has "some words" of quality. Some students in writing, write someone else's "bitter", write someone else's "Worry", write someone else's "strong", write someone else's "unfortunate", but put himself in the matter, so that their identity as "spectators." The author of this essay will be positioned in the "emotional center" to Simple words to express their true feelings: compassion and strong are in which we see not only the ruins, but the ruins of the sad and unyielding spirit of writing ability is a kind of emotional expression, and the expression of emotion The ability to be born, so your writing skills are born - but you sometimes ignore the grasp of this natural ability and dig. Please "own emotions" as the center of writing it, so that In the essay there is a "free heart."
At present, the market common sound barrier main material metal sound barrier, concrete sound barrier, PC sound barrier, glass steel sound barrier and so on. Metal sound barrier high cost, easy to rust; ordinary concrete from the major, low strength; PC sound barrier low hardness, poor UV resistance; FRP sound barrier cost is high, no fire. Magnesium sound barrier is made of modified magnesite cement as the base material of the new sound barrier, the current magnesia sound barrier with its unique advantages have been widely used in roads, light rail, railway, culverts, tunnels and other transportation areas.
A sound barrier is a facility that blocks sound waves between the sound source and the receiver, thereby reducing the noise in the area where the receiver is located. According to the sound barrier application environment, the sound barrier can be divided into traffic noise barriers, equipment noise attenuation noise barriers, industrial plant noise barriers three
