问题 计算题

右下图是某药厂生产的葡萄糖注射液的标签,其溶质葡萄糖的化学式为C6H12O6

试计算:

(1)配制一瓶5%葡萄糖注射液需要葡萄糖       g;

蒸馏水      mL。(假设该葡萄糖注射液的密度为1g/mL)

(2)葡萄糖的式量为             

(3)葡萄糖中碳、氢、氧三种元素的质量比为       

(4)90g葡萄糖中所含碳元素的质量与          g麦芽糖(C12H22O11 )中所含碳元素的质量相等。  

答案

(1)25    475 (2)180 (3)6:1:8 (4)85.5

题目分析:

(1)一瓶葡萄糖注射液的质量=500ml×1g/mL=500g

葡萄糖的质量=500g×5%=25g 

水的质量=500g-25g=475g

(2)葡萄糖的相对分子质量=12×6+12+16×6=180

(3)葡萄糖中碳、氢、氧三种元素的质量比=12×6:12:16×6=6:1:8

(4)设麦芽糖的质量为x,那么90g× 72/180 ×100%=72X/270  ×100%

X=85.5g

单项选择题

People from East Asia tend to have more difficulties than those from Europe in distinguishing facial expressions - and a new report published online in Current Biology explains why.

Rachael Jack, University of Glasgow researcher, said that rather than scanning evenly (均匀 的) across a face as Westerners do, Easterners fix their attention on the eyes.

"We show that Easterners and Westerners look at different face features to read facial expressions," Jack said. "Westerners look at the eyes and the mouth in equal measure, whereas Easterners favor the eyes and neglect (忽略) the mouth. "

According to Jack and her colleagues, the discovery shows that human communication of emotion is more complex than previously believed. As a result, facial expressions that had been considered universally recognizable cannot be used to reliably convey emotion in cross cultural situations.

The researchers studied cultural differences in the recognition of facial expressions by recording the eye movements of 13 Western Caucasian and 13 East Asian people while they observed pictures of expressive faces and put them into categories : happy, sad, surprised, fearful, disgusted, angry,

or neutral. They compared how accurately participants read those facial expressions using their particular eye movement strategies.

It turned out that Easterners focused much greater attention on the eyes and made significantly more errors than did Westerners. "The cultural difference in eye movements that they show is probably a reflection of cultural difference in facial expressions," Jack said. " Our data suggest that whereas Westerners use the whole face to convey emotion, Easterners use the eyes more and mouth less. "

In short, the data show that facial expressions are not universal signals of human emotion. From here on, examining how cultural factors have diversified these basic social skills will help our under- standing of human emotion. Otherwise, when it comes to communicating emotions across cultures, Easterners and Westerners will find themselves lost in translation.

What were the people asked to do in the study()

A. To make a face at each other.

B. To get their faces impressive.

C. To classify some face pictures.

D. To observe the researchers’ faces.

单项选择题