在英语中,coal(煤炭)这个单词是可数名词还是不可数名词?
Coal 不同的情况下,可数、不可数都可以用。
coal KK: [] DJ: [] n. 1. 煤[U]不可数 2. (燃烧中的)煤块[C] 可数3. 木炭[U] 不可数
vt. 1. 给...加煤 2. 把...烧成炭
vi. 1. 上煤,加煤 The ship called at Boston to coal. 船停靠在波士顿上煤。
Modern industrial society burning too much coal, oil and natural gas, a large number of exhaust emissions, the fuel combustion after release large amounts of carbon dioxide gas into the atmosphere caused by the greenhouse effect causes global warming. Because carbon dioxide has the function of heat absorption and heat insulation. With a lot of people cut down trees for greenhouse gas is absorbed by trees. North and south two polar ice melt, sea level rise, coastal areas will be flooded. The solution can be protect trees Cut use of fossil fuels and use clean energy
Air Pollution
空气污染
There are many chemicals that pollute the air. 污染空气的化学品有好多种。In cities, the major source of pollution is carbon monoxide. Carbon monoxide is caused most of the time by gasoline-powered motor vehicles.在城市里,主要的污染源是一氧化碳。多数时间,一氧化碳是由用汽油做动力的机动车产生的。 You might have felt some of the effects of air pollution in big cities.在大城市里,人们可能已感觉到一些空气污染的影响。 If you have ever visited a big city, you might have noticed that your eyes burned or that you had trouble breathing. 如果你参观过一个大城市,你可能已注意到,你的眼睛发烧,或者呼吸困难。Air pollution is a problem in big cities because cars, homes, and factories give off many kinds of harmful substances, or pollutants, into the air.空气污染在大城市里是一个问题,因为汽车、家庭和工厂向空气中排放出很多种有害的物质或污染物。
Concern about air pollution has recently focused on indoor pollution. 关于空气污染的担忧最近一直集中于室内污染。Indoor pollutants include tobacco smoke, gases from stoves, car exhaust in attached garages, and chemicals used for cleaning. 室内污染物包括香烟烟雾、烤炉的气体、在附属的车库中汽车的废气。Of special concern is a radioactive gas called radon. 其中特别引起关心的是称为氡气的放射性气体。Radon comes from traces of uranium and radium that exist in practically all rocks and soil. 氡来自于实际上存在于所有石头和土壤中的痕量铀和镭。Scientists think that every year as many as 30,000 of the 125,000 lung cancer deaths in the U. S. may be caused by radon. 科学家认为,每年,美国12万5千名肺癌死亡中有多达3万人可能是由氡引起的。
Sulfur dioxide is another kind of air pollutant.二氧化硫是另一种空气污染物。 It is released into the air when coal is burned.它在煤的燃烧时释放到空气中。 The sulfur dioxide combines with water in the air, forming sulfuric acid. 二氧化硫与空气中的水结合,形成硫酸。This weak acid becomes part of rainwater, which falls to the earth. 这种弱酸变成酸雨的一部分,降落到地球上。The acid rain harms living things and also damages buildings and other structures.酸雨有害于有生命的东西,也会损伤建筑和其他结构。
Some factories that burn coal have taken steps to cut down on acid rain. These factories have placed devices called scrubbers on their smokestacks. 有些燃煤的工厂已采取步骤来减少酸雨。这些工厂已在他们的烟囱上放置了称为洗涤器的装置。The scrubbers remove sulfur dioxide as it is released from burning coal.洗涤器在二氧化硫于煤燃烧而释放出来时,除去二氧化硫。
Place a few drops of hydrochloric acid on a piece of limestone.在一块石灰石上放几滴盐酸。 The reaction will cause a fizzing.化学反应会引起嘶嘶声。 This is similar to the results of acid rain.这与酸雨的结果类似。 In a few years, acid rain can have a dangerous effect on wildlife and eat away at buildings.在少数几年中,酸雨可以对野生动植物产生有害的影响并侵蚀建筑物。
Trees are an important wildlife resource that does more than provide peace and beauty. They add oxygen and water to the air. 树木是一种主要的动植物资源,它们做出了比提供宁静和美丽更多的贡献。They act as windbreaks and have a cooling effect on temperatures.它们起到了防风物的作用,而且对气温有冷却作用。 Their presence slows the runoff of rainwater, and their root systems hold the soil. Together, both functions prevent harmful soil erosion.它们的存在减缓了酸雨的流失量,它们的树根系统则保持了土壤。加在一起,这两种功能防止了有害的土壤侵蚀。
固定碳含量是指去除水分、灰分和挥发分之后的残留物,它是确定煤炭用途的重要指标。从100减去煤的水分、灰分和挥发分后的差值即为煤的固定碳含量。根据使用的计算挥发分的基准,可以计算出干基、干燥无灰基等不同基准的固定碳含量。
发热量(Q)
发热量是指单位质量的煤完全燃烧时所产生的热量,主要分为高位发热量和低位发热量。煤的高位发热量减去水的汽化热即是低位发热量。发热量的国标单位为百万焦耳/千克(MJ/KG)常用单位大卡/千克,换算关系为:1MJ/KG=239.14Kcal/kg1J=0.239cal1cal=4.18J。如发热量5500Kcal/kg,5500Kcal /kg=5500/239.14=23MJ/kg。
胶质层最大厚度(Y)
烟煤在加热到一定温度后,所形成的胶质层最大厚度是烟煤胶质层指数测定中利用探针测出的胶质体上、下层面差的最大值。它是煤炭分类的重要标准之一。动力煤胶质层厚度大,容易结焦;冶炼精煤对胶质层厚度有明确要求。
粘结指数(G)
在规定条件下以烟煤在加热后粘结专用无烟煤的能力,它是煤炭分类的重要标准之一,是冶炼精煤的重要指标。粘结指数越高,结焦性越强。
煤灰灰熔融性温度(灰熔点)
在规定条件下得到的随加热温度而变化的煤灰熔融性变形温度(DT)、软化温度(ST)、常用软化温度(ST)来表示。灰熔融性温度越高,煤灰不容易结渣。因锅炉设计不同,对灰熔融性温度要求也不一样。煤灰熔融性温度的高低,直接关系到煤作为燃料和汽化原料的性能,煤灰熔融性温度低,煤灰容易结渣,增加了排渣的难度,尤其是固态排渣的锅炉和移动床的汽化炉,煤灰熔融性温度要求较高。
哈氏可磨指数(HGI)
哈氏可磨指数是反应煤的可磨性的重要指标。煤的可磨性是指一定量的煤在消耗相同的能量下,磨碎成粉的难易程度。可磨指数越大,煤越容易磨碎成粉。在发电煤粉锅炉和高炉喷吹用煤中,可磨指数是质量评价的一个重要指标。
焦渣特征(CRC)
煤炭热分解以后剩余物质的形状。根据不同形状分为8个序号,其序号即为焦渣特征代号。
1---粉状。全部是粉末,没有相互粘着的颗粒。
2---粘着。用手指轻碰即成粉末或基本上是粉末,其中较大的团块一碰既成粉末。
3---弱粘性。用手指轻压既成小块。
4---不熔融粘结。用手指用力压才裂成小块,焦渣上表面无光泽,下表面稍有银白色光泽。
5---不膨胀熔融粘结。焦渣形成扁平的块,颗粒的界限不易分清,焦渣上表面有明显的银白色金属光泽,下表面银白色光泽更明显。
6---微膨胀熔融粘结。用手指压不碎,焦渣的上下表面均有银白色金属光泽,但焦渣表面具有较小的膨胀泡。
7---膨胀熔融粘结。焦渣的上下表面均有银白色金属光泽,明显膨胀,但高度不超过15mm。
8---强膨胀熔融粘结。焦渣的上下表面均有银白色金属光泽,焦渣高度大于15mm。
好多煤炭网站都有,可以自己去看看。