公筷行动英语

排放冷却是对流冷却的另一种。与再生冷却不同，用于排放冷却的冷却剂对推力室冷却吸热后不进入燃烧室参与燃烧，而是排放出去。直接排放冷却剂会降低推力室比冲，因此需要尽可能减少用于排放冷却的冷却剂流量，同时只在受热相对不严重的喷管出口段采用排放冷却。还有一种是辐射冷却，其热流由燃烧产物传给推力室，再由推力室室壁想周围空间辐射散热。辐射冷却的特点是简单、结构质量小。主要应用于大喷管的延伸段和采用耐高温材料的小推力发动机推力室。在组织推力室内冷却时，是通过在推力室内壁表面建立温度相对较低的液体或气体保护层，以减少传给推力室室壁的热流，降低壁面温度，实现冷却。内冷却主要分为头部组织的内冷却（屏蔽冷却）、膜冷却和发汗冷却三种方法。推力室采用内冷却措施后，由于需要降低保护层的温度，所以燃烧室壁面附近的混合比不同于中心区域的最佳混合比（多数情况下采用富燃料的近壁层），造成混合比沿燃烧室横截面分布不均匀，使燃烧效率有一定程度的降低。膜冷却与屏蔽冷却类似，是通过在内壁面附近建立均匀、稳定的冷却液膜或气膜保护层，对推力室内壁进行冷却，只是用于建立保护层的冷却剂不是喷注器喷入的，而是通过专门的冷却带供入。冷却带一般布置在燃烧室或喷管收敛段的一个横截面上。沿燃烧室长度方向上可以有若干条冷却带。为提高膜的稳定性，冷却剂常常经各冷却带上的缝隙或小孔流入采用发汗冷却时，推力室内壁或部分内壁由多孔材料制成，其孔径为数十微米。多孔材料通常用金属粉末烧结而成，或用金属网压制而成。此情况下，尽可能使材料中的微孔分布均匀，是单位面积上的孔数增多。液体冷却剂渗入内壁，建立起保护膜，使传给壁的热流密度下降。当用于发汗冷却的液体冷却剂流量高于某一临界值，在推力室内壁附近形成的是液膜。当冷却剂流量低于临界值流量时，内壁温度会高于当前压力下的冷却剂沸点，部分或全部冷却剂蒸发，形成气膜。除了以上热防护外，还有其他热防护方法如：烧蚀冷却、隔热冷却、热熔式冷却以及室壁的复合防护等。3 高焓气体发生器热防护方案综合上述方法结合实际情况，便得到高焓气体发生器的热防护方法。高焓气体发生器的燃烧室与液体火箭发动机的不同，省去前面的推力室部分，使得其结构更简单而有效。那么，所涉及到的热防护即为对燃烧室室壁的热防护部分。由于燃料进入燃烧室内迅速分解并放出大量

获悉中国在提倡全民公筷行动 Learn that Chinese public encourages Chinese people to use public chopsticks.

The use of chopsticks and spoons is not affectation, but for the sake of civilization and hygiene. This can not only protect themselves, but also protect others, which embodies a social responsibility. Let's work together to advocate new eating habits and healthy habits! Even if the epidemic is over, good eating habits will benefit us for life!使用公筷公勺不是矫情，而是为了文明和卫生。这既能保护自己，也能保护他人，更体现了一份社会责任。公筷公勺、举手之劳，让我们共同努力，倡导吃饭新风尚、健康好习惯！即使疫情过去，好的餐饮习惯也会让我们受益终生！

Table Manners The main difference between Chinese and western eating habits is that unlike the West, where everyone has their own plate of food, in China the dishes are placed on the table and everybody shares. If you are being treated by a Chinese host, be prepared for a ton of food. Chinese are very proud of their culture of cuisine and will do their best to show their hospitality. And sometimes the Chinese host use their chopsticks to put food in your bowl or plate. This is a sign of politeness. The appropriate thing to do would be to eat the whatever-it-is and say how yummy it is. If you feel uncomfortable with this, you can just say a polite thank you and leave the food there. Eating No-no's Don't stick your chopsticks upright in the rice bowl.Instead,lay them on your dish. The reason for this is that when somebody dies,the shrine to them contains a bowl of sand or rice with two sticks of incense stuck upright in it. So if you stick your chopsticks in the rice bowl, it looks like this shrine and is equivalent to wishing death upon a person at the table! Make sure the spout of the teapot is not facing anyone. It is impolite to set the teapot down where the spout is facing towards somebody. The spout should always be directed to where nobody is sitting, usually just outward from the table. Don't tap on your bowl with your chopsticks.Beggars tap on their bowls, so this is not polite.Also, when the food is coming too slow in a restarant, people will tap their bowls. If you are in someone's home,it is like insulting the cook. Drinking Gan Bei! (Cheers! “Gan Bei” literally means “dry [the] glass”) Besides beer, the official Chinese alcoholic beverage is Bai Jiu,high-proof Chinese liquor made from assorted grains. There are varying degrees of Bai Jiu. The Beijing favorite is called Er Guo Tou, which is a whopping 56% alcohol. More expensive are Maotai and Wuliangye. Of course, the main difference on the Chinese dinner table is chopsticks instead of knife and fork, but that’s only superficial. Besides, in decent restaurants, you can always ask for a pair of knife and fork, if you find the chopsticks not helpful enough. The real difference is that in the West, you have your own plate of food, while in China the dishes are placed on the table and everyone shares. If you are being treated to a formal dinner and particularly if the host thinks you’re in the country for the first time, he will do the best to give you a taste of many different types of dishes. The meal usually begins with a set of at least four cold dishes, to be followed by the main courses of hot meat and vegetable dishes. Soup then will be served (unless in Guangdong style restaurants) to be followed by staple food ranging from rice, noodles to dumplings. If you wish to have your rice to go with other dishes, you should say so in good time, for most of the Chinese choose to have the staple food at last or have none of them at all. People in China tend to over-order food, for they will find it embarrassing if all the food is consumed. When you have had enough, just say so. Or you will always overeat!