chocolate, one of the most popular foods in the world, can be seen in every corner of the world.but before 2018 npu-qmul summer camp, we have never imagined making our own chocolate in a lab.
at the beginning of the session, dr. zhang gave us a lecture about the chocolates, including their history and crystal structures. then, we were asked to make one good and one bad chocolate by using both dark and milk chocolates to see whether the physical and chemical properties would be different when we changed the crystal structure.
according to the information about six main crystal structures in them, we could know how to make good and bad chocolates. for bad chocolates, we needed to melt them at 46℃ and cool them down to room temperature. but to make good chocolates, we needed to follow four steps: melting at 46℃, cooling down to 26.5℃, heating to 31℃ and cooling down to room temperature. and after we finished our own samples, we had a chance to test their mechanical properties and see their micro-structure.
workshop–tabletidy
all the students and teachers in the summer school took part in the workshop activity about making a table tidy. at first, the teacher introduced the process. the students need to use a piece of plastic to make a table tidy via several steps. then it was the students’ time to act. the plastic board was marked according to the graft and cut into desired shape. then the electric drill was used to drill the board. next, the specific parts on the plastic were heated up to make it soft. the plastic was folded into certain angle after that. the magnet and sticky note were stuck on the table tidy at last. the activity increased the operational ability. it also familiarized us with some useful tools helpful in the future laboratory work.
practical–air vehicle manufacturing and competition
in this activity, we were asked to make a car with a diameter no more than 250 mm using 4 plastic lids, 8 drinking straws, 2 pieces of tissue paper, a roll of tape and a pair of scissors. the car moves the furthest distance driven by wind would win the competition. and in the actual process, we did find many delicate designs, such as making a sail and fans to increase the wind area or just simplifying the structure to reduce the internal friction.
li yifan
“cooperation enables a group to succeed.” in the experiment of making chocolate, i strongly realized how important a good teamwork could be. in my opinion, a good and efficient team means everyone must be clear about his/her assignment and be responsible for his/her part. at the same time, we must fully trust each other. so that it can save a great deal of time especially in doing simple but repetitive work.
“practicing is much more difficult than looking and imaging.” when i saw the blueprint, i thought it was not difficult to make a table tidy. but actually, it was not the case at all. i could not draw the parallel lines exactly, not to mention the circles. when i tried to cut shapes with a saw, i always thought that if i failed, i would not have a chance to change them. and the fear made me almost impossible to start. this was also the first time i knew that how horrible the electric saw could be, and how difficult it was to control. after that, i really understand how difficult and significant the practice is and why people always say that practice makes perfect.
“collective wisdom is always better than personal thinking.” to be honest, our final design was completely different from our original ideas. but we all believed that this was the best design we could think of, and it did not disappoint us. in the process of making the air vehicle, i strongly understood why discussion was so important. all of our views have a limitation and we cannot think of every single detail by ourselves. in the course of the discussion, not only will your ideas be complemented, but you'll also learn many other people's ways of thinking and perspectives.
zhang zexuan
in these two weeks, we finished three experiments in total. i did ‘how to make chocolate’ and ‘practical - air vehicle manufacturing and competition’ with my group members, and completed ‘workshop activity - table tidy’ by myself.
in the first two cooperative experiments, i have learned how to work in groups. we should cleanly define and separate roles before beginning a task, and respecting others is also important. during an experiment, enough communication is necessary, because we are a team and we need to understand each other. honestly, i am not good at cooperating with others, so i appreciate it that this summer school gives me the precious chance to learn and improve it. what’s more, when we were making an air vehicle, my group members showed me how to use the creative and critical thinking ingeniously. i think i have learned a lot from them.
when iwasdoing the experiment by myself, it truly improved my operational ability. i had many problems during the activity, and i needed toask forhelp from teachers and classmates. i think it is another practice. when i finished, i felt contented: this is made by myself. it may be not delicate enough, but it is priceless.
as students of the qmes, the practical and creative ability are necessary. and these practical courses have exercised these two abilities in a relaxing and enjoyable way. the real scientific practice cannot be easy like these, it may be more difficult. but it is the growth of experience, and the cultivation of interest, that can help students to explore more and become excellent students in sems.
zhang xiaoyang
in making the chocolate, i found it's of great importance to cooperate. we needed to make 4 different chocolatesin total. each one of us found what we were good at and did it as careful as possible. as long as everyone in a group finishes his own work, the task will be much easier.
the other day we did experiment, i had difficulty polishing the holes on it. i felt anxious when i thought i couldn't make it. however, i realized it doesn't matter if i couldn't make it perfect. as long as i did my best, i finished the task. at last, although my work was not smooth enough, i thought itwasperfect.
the last experimentwas making a vehicle. most people thought they were supposed to make a car with four wheels. but we thought out another plan– a vehicle with two wheels. as a result, vehicles with two wheels move further than that with four wheels. i thought this was the power of creativity. if we can find a new way that nobody has found, maybe we can do better than others. so, it's necessary to always be creative.
yang jiye
in the activity of how to make chocolate, i learned how different cooling methods would affect the quality of the chocolate. and via our actual practice, the differences could be seen clearly. what impressed mewas that we made the worst one because of the mistake in controlling the temperature. i learned that if we wanted to make things perfect, we cannot ignore any step. in the activity of making the table tidy,i felt the happiness of creating. i also got some basic skills to use the tools in the laboratory. one of my favorite parts in the whole summer school is the air vehicle competition. i think the idea of our group is great. we just used two wheels to reduce the friction. and we also added a small fan to push the vehicle forward. though our group did not win the competition, the experience of brain storming and group work were amazing.
liao wenxuan
during the summer school days, we had three meaningful activities: how to make good chocolate,air vehicle manufacturing and competition,and workshop activity - table tidy.
in the process of making chocolate, i felt that it was not easy to do an experiment. even the simple action of heating, cooling and reheating was done step by step according to the standard because a little deviation in operation could make a big difference.
in workshop activity - table tidy, i felt that to be a good engineer, theoretical knowledge is not enough. in air vehicle manufacturing and competition, i learned that it is not easy for a team tocome to a consensus. one person's idea to convince others must have clear logic and feasible operation. therefore, the idea of a team is not so easy to achieve. each member has his/her own ideas. to reach an agreement,one must learn how to express his/her ideas better and learn how to compromise.
by li yifan, zhang zexuan, zhang xiaoyang, yang jiye, liao wenxuan
