essential nutrient element

Cadmium is not an essential nutrient element for plants , but iron is the essential one .

镉是植物的非必需元素，而铁是植物生长发育过程中必不可少的元素。

Cadmium is one of the most toxic heavy metals and is not an essential nutrient element for plant , animal and human being .

镉是动物和植物的非必需元素，也是毒性最大的重金属之一。

Zinc is an essential nutrient element for biological organisms , but it is toxic to plant , animal and human at excess levels .

锌是生物必需微量元素，但过多时对动植物都有毒害。

Selenium ( Se ) is an essential nutrient element for human beings . Many diseases may be caused by Se deficiency or Se excess .

硒（Se）是人体必需的营养元素之一，缺乏或过量都会使人产生多种病症。

Nitrogen and phosphorus compounds are very essential nutrient element for all forms of life in the water . However , too much of it can lead eutrophication .

氮磷化合物是水中所有生命的基本营养元素，但是过量的氮和磷又会引起富营养化。

Orthophosphate is an essential nutrient element for phytoplankton in ocean environment , and plays an important role in the marine biogeochemical cycle of phosphorus .

活性磷是海洋浮游植物生长所必需的物质基础，在磷的海洋生物地球化学过程中扮演着重要角色。

DMA is an essential nutrient element for healthy growth and development of infants and children . It is also effective in treating and preventing cardiovascular diseases and cancers .

它具有多种与我们身体健康有密切关系的生理功能，是婴幼儿健康成长过程中不可缺少的营养因子，同时对防治心脑血管疾病和抗癌也有很好的功效。

Magnesium has excellent biocompatibility and is an essential nutrient element for human . So it has good prospects as the biological material . Poor corrosion resistance of magnesium alloys provide a guideline for the development of biodegradable metallic materials in the medical field .

同时，镁具有良好的生物相容性，镁离子是一种人体必需的营养素，因此镁合金作为生物材料具有很好的发展前景。