透热转气

变异系数(CV)描述的是获得单位的预期收益须承担的风险。变异系数CV=标准差/持有期收益率。( )

简述微泡浮选柱的工作原理？

某学生早锻炼时不慎踝关节扭伤，2h后来到医务室就诊，正确的处理方法是 ( )。

A．热敷
B．冷敷
C．冷热敷交替使用
D．热水足浴
E．夹板固定

如果异步电动机轴上负载增加，其定子电流会减小。

Have you had a headache during a test Have you ever been so worried about something that you have a headache or even can’t sleep at night If so, then you know what stress is. Stress is what you feel when you are worried about something. This worry in your mind can make your body feel bad. You may feel angry, sad, scared, or afraid—all of which can give you a stomachache or a headache.
However, there are different kinds of stress. Some kinds of stress are good and others are bad. Good stress might happen when you’re called to answer questions in class or when you have to give a speech. This kind of stress can help you to get things better done. For example, you may do a better job on your test if the stress pushes you to prepare better before the test.
On the other hand, bad stress can happen if stress lasts too long. You may not feel well if your parents are fighting, if a family member is sick, if you’re having problems at school, or if anything else makes you unhappy every day. That kind of stress isn’t going to help you. And it can actually make you sick.
The best way to fight stress is to have a balanced life. Make sure you keep your SELF in mind: Sleep, Exercise, Leisure(休闲), and Food. If you get enough sleep and eat properly, and if you exercise and leave time for fun, you’ll probably feel less stressed.