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1 实验材料青霉素小药瓶1个,1号干电池3节,小灯泡(2.5 V,0.3 A)1个,缝衣钢针(长度5.0～7.0 cm)2枚,导线3根,胶带1卷,食盐,纯碱,蔗糖,纯净水。2 组装实验装置(1)将青霉素小药瓶上的铝皮去掉,清洗药瓶及瓶塞。(2)使缝衣钢针穿线孔朝上、针尖朝下插入瓶塞,最好使钢针插在塞子内部的小圈壁上,以利于固定,并使两针保持相对最大距离,调整插入长度,使钢针下部尖端正好触及瓶底。
1 Experimental material: 1 penicillin vial, 3 cells of No. 1 dry cell, 1 bulb (2.5 V, 0.3 A), 2 needles (5.0 to 7.0 cm in length), 3 wires, 1 roll of tape, Salt, soda ash, sucrose, pure water. 2 Assemble the experimental device (1) Remove the aluminum skin from the penicillin vial and clean the vial and stopper. (2) Insert the sewing needle with the threading hole up and the needle tip down into the stopper. It is better to insert the needle into the small circle inside the stopper to facilitate fixing and keep the two needles at the maximum distance. Adjust the insertion. The length makes the tip of the needle just touch the bottom of the bottle.