学术交流英语稿子

The first ppt (0—0:20）

Good morning everyone ! My name is Arvin. I come from the university of Science and Technology of China.Today I will discuss how to extract the hdyrogen by a new method.

The second ppt （0:20—1:00）

At present our environment is suffering from serious pollution, the blue sky has disappeared. We have to face the dreaded PM2.5 almost everyday. Why ? Why our environment become so bad. One of the important reasons is the overuse of fossil fuels, such as coal and oil. These fossil fuels have a great impact on our environment.

The third ppt （1:00—1:45）

Currently, the more serious problem is that the fossil energy is also vanishing rapidly. For the developing countries like china, the annual demand for energy is very large. However, Coal reserves can be only mined for 152 years and we can only use 40 years of oil. So it is emergency to find a apporpriate alternative.

The fourth ppt （1:45—2:35）

Hydrogen is a wonderful substitute,because it is a clean energy and also have high calorific value. There are a variety of ways to produce hydrogen. Such as biological、water electrolysis and Chemical methods. However, there methods are too expensive or unfriendly to the environment. So we propose a new method for producing hydrogen, we

obtain hydrogen by the reaction of aluminum with water.

The fifth ppt （2:35—3:20）

If we want to use this way to extract hydrogen, we should solve two challenging problem, on the one hand, there is a native thin oxide layer on the aluminum surface which prevent water from reacting with aluminum. On the other hand, How to save the activated aluminum powder is also a big problem. Due to the activated aluminum powder is easy to be oxidized by air.

The sixth ppt （3:20—3:58)

In order to activate the aluminum, firstly, we add some additives into the aluminum to make alloys. Then alloy was milling with the salt. Salt can not only activate the aluminum but also protect it from air oxidation. With these methods, the aluminum can react with water at room temperature to release hydrogen.

The seventh ppt (3:58—4:58)

Next I will introduce some of the factors that affect the hydrogen evolution reaction. The first factor is temperature. From this graph, we can see that the conversion yield enhanced steadily with the increase of reaction time. And the hydrogen generation rate increases sharply when we increase the temperature of water.

The Eighth ppt (4:58—5:50)

The second factor is salt-to-aluminum mole ratio. This a indicates

salt-to-aluminum mole ratio. The following points can be concluded from this graph. First, the hydrogen evolution rate increases with the increase of the mole ratio, the total reaction time is shorter When the mole ratio is higher. Second, the conversion yield can reach sixty percent when the mole ratio is 1. However, if we raise the mole ratio above 1.5, the reaction efficiency can reach one hundred percent. Third, There is no significant difference betweeen the case with a=4 and a=7.

The ninth ppt （5:50—6:48）

The final factor is the effect of additives on hydrogen generation rate. From this picture we can see that hydrogen generation rate of alloys are greater than corresponding powders have no additives, The effect of adding Bi on the reaction rate is the most obvious, and the effect is the best. Additives also have the ability to omit delay time.

The Tenth ppt （6:48—7:40）

I have introduced that there is a dense oxide film on the surface of the aluminum. So we activate the aluminum by mechanical milling of aluminum and salt. Then we studied the effect of the salt-to-aluminum mole ratio on the hydrogen generation rate. And we find that the optimum salt-to-aluminum mole ratio was 4. Finally, we studied the effect of additives on hydrogen generation rate, Adding 7 wt% sillcon, graphite or bismuth additives can greatly increase the rate.

The eleventh ppt （7:40—8:50）