parts per million

简明释义

百万分之几

英英释义

例句

1.During the experiment, we found that the sample contained 25 parts per million of mercury.

在实验过程中，我们发现样本中含有25百万分之一的汞。

2.The concentration of lead in the water was measured at 10 parts per million, indicating a potential health risk.

水中铅的浓度测量为10百万分之一，这表明存在潜在的健康风险。

3.To ensure quality, the manufacturer tests for contaminants at levels below 1 parts per million.

为了确保质量，制造商测试污染物的水平低于1百万分之一。

4.The food safety standards require that pesticide residues do not exceed 5 parts per million.

食品安全标准要求农药残留不得超过5百万分之一。

5.In the air quality report, carbon dioxide levels were noted to be around 400 parts per million.

在空气质量报告中，二氧化碳水平被记录为大约400百万分之一。

作文

Understanding the concept of parts per million is essential in various fields, including environmental science, chemistry, and engineering. The term parts per million (ppm) refers to a measurement that indicates the concentration of one substance in a million parts of another. This unit of measurement is particularly useful when dealing with very dilute solutions or when measuring trace amounts of a substance in a mixture. For example, if we are discussing the concentration of pollutants in water, saying there are 10 parts per million of a particular contaminant means that for every million molecules of water, there are 10 molecules of that contaminant.In environmental science, understanding parts per million is crucial for assessing air quality and the presence of greenhouse gases. For instance, carbon dioxide (CO2) levels in the atmosphere are often expressed in ppm. As of recent reports, CO2 concentrations have surpassed 400 parts per million, which raises significant concerns about climate change and its impact on global temperatures. Monitoring these levels helps scientists understand trends over time and make predictions about future climate scenarios.Moreover, in the field of chemistry, parts per million is a common way to express the concentration of substances in solutions. For example, when preparing a chemical solution, a chemist may need to dissolve a specific amount of solute in a large volume of solvent. If a chemist states that a solution has a concentration of 500 parts per million, it implies that there are 500 grams of solute in one million grams of solution. This precise measurement is vital for conducting experiments and ensuring safety in laboratories.Engineering applications also rely heavily on the concept of parts per million. In manufacturing processes, especially in the semiconductor industry, controlling the purity of materials is critical. Even a tiny contamination level measured in parts per million can lead to defects in microchips, impacting performance and reliability. Engineers must monitor and maintain the quality of raw materials to ensure they meet stringent specifications, often expressed in ppm.In conclusion, the measurement of parts per million is a fundamental concept that spans multiple disciplines. Whether it is assessing environmental pollutants, preparing chemical solutions, or ensuring the quality of materials in engineering, understanding this unit of measurement is crucial. It allows professionals to communicate effectively about concentrations and ensures that they can make informed decisions based on accurate data. As we continue to face challenges related to pollution and resource management, the importance of accurately measuring and interpreting parts per million will only grow, highlighting the need for awareness and education on this topic among both professionals and the general public.

理解“百万分之一”这一概念在多个领域中是至关重要的，包括环境科学、化学和工程。术语百万分之一（ppm）指的是一种测量，表示一种物质在另一种物质的一百万部分中的浓度。这种测量单位在处理非常稀溶液或测量混合物中微量物质时尤为有用。例如，如果我们讨论水中污染物的浓度，说明某种污染物的浓度为10 百万分之一，意味着每一百万个水分子中有10个该污染物分子。在环境科学中，理解百万分之一对评估空气质量和温室气体的存在至关重要。例如，二氧化碳（CO2）在大气中的浓度通常以ppm表示。根据最近的报告，CO2浓度已超过400 百万分之一，这引发了人们对气候变化及其对全球气温影响的重大担忧。监测这些水平有助于科学家了解随时间变化的趋势，并对未来的气候情景做出预测。此外，在化学领域，百万分之一是一种常用来表达溶液中物质浓度的方式。例如，当准备化学溶液时，化学家可能需要将特定量的溶质溶解在大量溶剂中。如果化学家声明某溶液的浓度为500 百万分之一，则意味着在一百万克溶液中有500克溶质。这一精确的测量对于进行实验和确保实验室安全至关重要。工程应用也严重依赖于百万分之一的概念。在制造过程中，尤其是在半导体行业，控制材料的纯度至关重要。即使是以百万分之一计量的微小污染水平也可能导致微芯片缺陷，从而影响性能和可靠性。工程师必须监测和维护原材料的质量，以确保它们符合严格的规格，这些规格通常以ppm表示。总之，百万分之一的测量是一个跨越多个学科的基本概念。无论是评估环境污染物、准备化学溶液，还是确保工程材料的质量，理解这个测量单位都是至关重要的。它使专业人员能够有效地沟通浓度，并确保他们能够基于准确的数据做出明智的决策。随着我们继续面临与污染和资源管理相关的挑战，准确测量和解释百万分之一的重要性只会增加，这突显了在专业人士和公众中提高对此主题认识和教育的必要性。