parts per million

简明释义

百万分之一的零件不合格率质量标准

英英释义

例句

1.To ensure safety, the maximum allowable limit for arsenic in food is set at 10 parts per million (百万分之一).

为了确保安全，食品中砷的最大允许限值设定为10 百万分之一 (百万分之一)。

2.The laboratory reported that the mercury levels in the fish sample were 0.3 parts per million (百万分之一).

实验室报告称鱼样本中的汞水平为0.3 百万分之一 (百万分之一)。

3.In some agricultural products, pesticide residues can be found in concentrations as low as 5 parts per million (百万分之一).

在一些农产品中，农药残留的浓度可以低至5 百万分之一 (百万分之一)。

4.The concentration of lead in drinking water was measured at 15 parts per million (百万分之一).

饮用水中铅的浓度被测量为15 百万分之一 (百万分之一)。

5.Air quality tests showed that the level of ozone reached 180 parts per million (百万分之一) on hot summer days.

空气质量测试显示，炎热夏季的臭氧水平达到了180 百万分之一 (百万分之一)。

作文

In the realm of environmental science and chemistry, the term parts per million (百万分之一) is frequently used to measure the concentration of substances in various contexts. This unit of measurement indicates how many parts of a substance are present in one million parts of a solution or mixture. It is particularly useful when dealing with very dilute solutions where traditional measurements, such as percentages, become impractical. For instance, in air quality studies, scientists often measure pollutants, such as carbon dioxide or sulfur dioxide, in parts per million (百万分之一). This allows for a more precise understanding of how these gases affect the environment and human health.The significance of parts per million (百万分之一) extends beyond environmental science. In the field of food safety, regulatory agencies monitor the levels of contaminants in food products. For example, the permissible limit of lead in drinking water is often expressed in parts per million (百万分之一). This ensures that consumers are protected from harmful substances that could pose serious health risks. Similarly, in pharmaceuticals, the purity of a drug is sometimes evaluated in parts per million (百万分之一), ensuring that the active ingredients meet safety standards before reaching patients.Moreover, the application of parts per million (百万分之一) is also prevalent in industrial processes. Manufacturers often need to control the concentrations of various chemicals in their production lines. For example, in semiconductor manufacturing, impurities can significantly affect the performance of electronic components. Therefore, maintaining certain levels of contaminants in parts per million (百万分之一) is crucial for ensuring the quality and reliability of the final products.Understanding parts per million (百万分之一) is essential for interpreting scientific data accurately. For instance, a reading of 400 parts per million (百万分之一) of carbon dioxide in the atmosphere indicates that for every million air molecules, 400 are carbon dioxide. This metric is vital for assessing trends in climate change and developing strategies to mitigate its impacts. As global temperatures rise, monitoring the concentration of greenhouse gases in parts per million (百万分之一) becomes increasingly important for policymakers and researchers alike.In conclusion, the concept of parts per million (百万分之一) serves as a fundamental measurement in various disciplines, providing insights into environmental health, food safety, industrial processes, and scientific research. Its ability to convey minute quantities makes it an invaluable tool in our efforts to understand and address complex issues affecting our world. By grasping the implications of parts per million (百万分之一), we can better appreciate the delicate balance of our ecosystems and the importance of maintaining safe and healthy environments for future generations.