天气预报15天查询> 其他> 音分为哪两类

音分为哪两类

更新时间: 2020-10-28 00:00:00     

音是由物体振动发出的,分为乐音和噪音两种。<br>声音是由物体振动产生的声波。是通过介质(空气或固体、液体)传播并能被人或动物听觉器官所感知的波动现象。最初发出振动(震动)的物体叫声源。声音以波的形式振动(震动)传播。声音是声波通过任何介质传播形成的运动。<br>声音是一种波。可以被人耳识别的声(频率在20Hz~20000Hz之间),我们称之为声音。

关键词: 分为

如有意见、反馈、侵权或投诉等情况,请联系:

电话:
邮箱:

我们将会在48小时内给与处理!

版权所有 Copyright ? 2009-2020 tianqiyubao3.com

页面:/news/view-805469/ | 耗时:0.3216 s | 内存:1.89 MB | 查询:4 | 缓存读取:4 写入:0 | 加载文件:23
select * from tbl_Articles WHERE ArticleID=805469 LIMIT 0,1
select * from tbl_Articles_data WHERE ArticleID=805469 LIMIT 0,1
select * from tbl_Articles_sphinx where id=805469 LIMIT 0,1
SELECT ArticleID,Title FROM tbl_Articles WHERE ArticleID IN(444020,1634372,236963,3369302,2151531,131087,1282945,796818,3192072,2840318,1342953,256909,1389661,2541781,1119205,1130114,2157951,2136505,3419929,352557,1124963,451909,2195223,316705,264722,1096687,123669,1129661,3149084,741697) ORDER BY field (ArticleID,444020,1634372,236963,3369302,2151531,131087,1282945,796818,3192072,2840318,1342953,256909,1389661,2541781,1119205,1130114,2157951,2136505,3419929,352557,1124963,451909,2195223,316705,264722,1096687,123669,1129661,3149084,741697)