parts per million

简明释义

百万分之……百万分之几

英英释义

例句

1.The concentration of lead in the water was measured at 10 parts per million (百万分之一).

水中铅的浓度测量为10 百万分之一 (百万分之一)。

2.In this experiment, we found that the soil contained 50 parts per million (百万分之一) of arsenic.

在这个实验中，我们发现土壤中含有50 百万分之一 (百万分之一) 的砷。

3.The environmental report indicated that the mercury levels in the fish were 2 parts per million (百万分之一).

环境报告指出，鱼类中的汞含量为2 百万分之一 (百万分之一)。

4.The manufacturer claims that their product has a sodium content of only 5 parts per million (百万分之一).

制造商声称他们的产品钠含量仅为5 百万分之一 (百万分之一)。

5.Air quality standards dictate that ozone levels should not exceed 180 parts per million (百万分之一) during the summer months.

空气质量标准规定，夏季臭氧水平不得超过180 百万分之一 (百万分之一)。

作文

The concept of parts per million (ppm) is a crucial measurement used in various scientific disciplines, particularly in chemistry and environmental science. It refers to the number of units of a substance in a million units of total solution or mixture. This measurement is particularly useful when dealing with very dilute concentrations of substances, such as pollutants in air or water. For example, if a water sample has a concentration of 1 ppm of a certain contaminant, it means that there is one part of that contaminant for every million parts of water. 百万分之一的概念在科学研究中具有重要意义，特别是在化学和环境科学领域。它指的是在总溶液或混合物中的一百万个单位中某种物质的单位数量。这种测量在处理非常稀薄的物质浓度时尤其有用，例如空气或水中的污染物。In environmental studies, parts per million is often used to express the concentration of greenhouse gases, heavy metals, and other hazardous substances. For instance, scientists monitor the levels of carbon dioxide (CO2) in the atmosphere, which is measured in ppm. As of recent data, CO2 levels have been reported to be around 400 ppm, indicating a significant increase over the past century due to human activities such as burning fossil fuels and deforestation. This rise in ppm is alarming because it correlates with climate change and global warming. 百万分之一通常用于表达温室气体、重金属和其他有害物质的浓度。例如，科学家监测大气中二氧化碳（CO2）的水平，这通常以ppm为单位进行测量。根据最近的数据，二氧化碳的水平已经达到约400 ppm，这表明由于燃烧化石燃料和森林砍伐等人类活动，过去一个世纪内这一数值显著增加。这种ppm的上升令人担忧，因为它与气候变化和全球变暖相关联。Moreover, in industrial applications, parts per million is vital for quality control and safety standards. Manufacturers must ensure that the levels of certain chemicals in their products do not exceed specified ppm limits to protect consumer health and comply with regulations. For instance, the permissible limit for lead in drinking water is set at 15 ppb (parts per billion), which is equivalent to 0.015 ppm. This strict regulation highlights the importance of monitoring and controlling contaminants at very low concentrations. 在工业应用中，百万分之一对于质量控制和安全标准至关重要。制造商必须确保其产品中某些化学物质的含量不超过规定的ppm限值，以保护消费者健康并遵守法规。例如，饮用水中铅的允许限值设定为15 ppb（十亿分之一），这相当于0.015 ppm。这一严格的规定突显了在非常低浓度下监测和控制污染物的重要性。In conclusion, understanding parts per million is essential for anyone involved in scientific research, environmental protection, or industrial manufacturing. It provides a standardized way to quantify very small concentrations of substances, allowing for better analysis and decision-making. As we continue to face challenges related to pollution and resource management, the significance of ppm will only grow, underscoring the need for accurate measurements and responsible practices. 总之，理解百万分之一对于任何参与科学研究、环境保护或工业制造的人来说都是至关重要的。它提供了一种标准化的方法来量化物质的非常小的浓度，从而使分析和决策更加准确。随着我们继续面临与污染和资源管理相关的挑战，ppm的重要性将愈加凸显，强调了准确测量和负责任实践的必要性。