7矿井瓦斯(Mine Gases).pptxVIP

Mine Gases Introduction General properties of gases Gas accumulation and stratification Gases derived from combustion processes Gases from explosives Natural occurrences of gases New Words and Expressions Outline 通过学习，熟记propane 丙烷、carbon dioxide 二氧化碳、Stratification 分层、Buoyancy 浮力、Turbulence 湍流、hydrocarbon 碳氢化合物（烃类）、carbon monoxide 一氧化碳等专业词汇，达到英文与中文相互熟练翻译的程度； 深入理解Introduction、General properties of gases等内容，达到熟练阅读和正确、通顺地翻译的程度； 了解Gases derived from combustion processes、Gases from explosives、Natural occurrences of gases等内容，达到比较熟练和比较通顺翻译的程度。 Objectives It is generally assumed when referring to gases in the mining environment that the interest is in toxic gases, however, the concentration of nontoxic gases, such as oxygen, can be of importance. 一提到矿山环境中的气体，人们一般想当然地关心有毒气体。然而，无毒气体的浓度，例如氧气，也很重要。 注: assumed 想当然的 1 Introduction Gases in the mine environment come from different sources. The major concern about most gases is their toxicity to workers. If the concentration of and exposure time to a gas are sufficient, illness or death may result. 矿山中的气体来源很多。人们对大多数气体主要关注的是它们对工人产生的毒性。如果某种气体的浓度足够大，人们暴露在该气体中的时间足够长，就可能导致疾病或者死亡的产生。 1 Introduction During an emergency when a toxic gas or gases are released into the workplace, the concentration of the toxins can exceed normal workplace standards. This situation may pose a short-term or acute risk because of the increased toxicity of the higher concentration. As well, the reduction of oxygen in the air may also pose a risk to life because oxygen is needed to sustain life. 当某种或几种有毒气体释放到工作场所这种突发事件发生时，毒素的浓度会超过工作场所的正常标准。这种情况可能造成短期或严重的危险，因为它产生了高浓度的毒性物质。同时，空气中氧气的减少对生命形成了危险，因为氧气是维持生命所必须的。 1 Introduction The term gas refers to the physical state of a substance at room temperature and normal atmospheric pressure that, when unconfined, expands to fill the space it occupies. At reduced temperatures or high pressures, a gaseous substance can exist in a different physical state. Examples include the liquid propane gas and the solid dry ice that, at r