问题 问答题 简答题

试样的制备的基本程序?制备试样时应注意事项

答案

参考答案:

试样制备的基本程序有以下几个步骤:

破碎粗碎、中碎、细碎、粉碎;过筛;混匀;缩分

试样制备的注意事项有以下几点:

1)制样时,应先对所有的工具及设备用刷子刷净,不应有其他样品粉末残留

2)破碎样品时,应尽量防止样品小块或粉末飞散,如果偶然跳出大颗粒,必须拣回。

3)要避免样品在制备过程中被玷污,因此要避免机械、器皿污染,以及样品和样品之间的交叉污染。

制备好的合格试样应及时封存保管,贴上统一的试样标签,以便识别。标签应注明试样名称、检验项目、取样日期、制样人等项目。试样交付给测试者时应有签收手续。

单项选择题
单项选择题

After winning a big game, athletes are often asked how they feel. Usually athletes say how (1) it is to win this big game. On the contrary, the fact is that losing a big game, or in my case, all the games, can be even harder.

From the spectators’ point of view, last year’s basketball (2) for my high school team was nothing (3) of an embarrassment. And (4) 0 and 20 is certainly nothing to be proud of, that season had a bigger impact on me than any other. As a team captain, I knew it probably wouldn’t be the (5) year, but did I ever think we would lose every game Of course not. Since six of our top players had graduated, it was clear that we were a (n) (6) team who would struggle. The struggle began earlier than expected, (7) , as our team center was suspended (禁赛) for the season, and two key members decided to (8) for some reason. At this point, dropping out probably passed through every player’s mind, but in the end, we all stuck if out, (9) to work still harder.

Then there came a time when even our (10) and given up on us. Personally, I felt like it was (11) worthwhile giving my all. I thought, if even the coach doesn’t believe in us, why should I But just as my hope began to (12) , a teammate called a meeting. He said," Nobody thinks we are going to win, but, as teammates and friends, we (13) it to each other to go all out every game. "

It was that moment that (14) me how to be a leader. It hit me that I certainly didn’t (15) the role. As a leader you can never quit (16) the team who looks up to you. It is one (17) to be named captain, feel great and go through the motions, but it is quite another to be a real captain and make sure everyone realizes their full (18) all the time.

I am sure it is great to go through without losing and bringing home awards. But in all honesty, I (19) the fact that my team lost every game last year. It may not help me to become a better basketball player, but it already has made me a better leader, and (20)

10().

A.fans

B.classmates

C.sponsor

D.coach