What's more, when a vibration test was performed in this condition, no loosening occurred, indicating that a self-locking effect is present even if the nut is not fully tightened.
You would recognize a self signed certificate by the fact that subject and issuer fields contain the same string while there is no certificate attribute set indicating this is a ca certificate.
自签署证书的特征是，主题和颁发者字段包含相同的字符串，而且没有设置表示这是ca证书的证书属性。
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Usage: It is used for the products measuring, speed indicating, self-stopping of textile fabric equipments for plastic leather, capet, papermaking etc.