概括
植物的叶子吸收大气中的多双 (PCB),取决于物种的不同数量. 工厂类型之间的这种一致差异为具有成本效益的大气PCB监测提供了一个潜在的方法.
科学领域:
- 环境化学环境化学
- 植物生物学 植物生物学
- 大气科学 大气科学
背景情况:
- 多双 (PCB) 是持久性有机污染物,已知存在于大气中.
- 众所周知,植物叶子与大气污染物相互作用,包括PCB蒸气.
- 植物物种中污染物吸收的变化是一个公认的现象.
研究的目的:
- 为了研究植物叶片中大气中多双 (PCB) 的积累.
- 量化不同植物物种中叶子和大气中的PCB度之间的关系.
- 评估使用植物叶片分析用于大气PCB监测的潜力.
主要方法:
- 控制暴露实验或对各种植物物种的实地采样.
- 在植物叶片和环境空气中分析PCB度.
- 计算积累因子和评估物种间的变化.
主要成果:
- 植物叶子明显从大气中积累了PCB.
- 在植物物种之间观察到一致的差异积累因子.
- 这一因素在广泛的PCB度范围内保持稳定.
结论:
- 植物物种表现出不同的能力来积累大气中的PCB.
- 不同积累因子的稳定性表明了对物种特定校准的潜力.
- 叶片PCB分析为大气PCB监测提供了一个有希望的,具有成本效益的方法.
相关概念视频
01:29Covalent Bonds
When two atoms share electrons to complete their valence shells they create a covalent bond. An atom’s electronegativity—the force with which shared electrons are pulled towards an atom—determines how the electrons are shared. Molecules formed with covalent bonds can be either polar or nonpolar. Atoms with similar electronegativities form nonpolar covalent bonds; the electrons are shared equally. Atoms with different electronegativities share electrons unequally, creating polar bonds.A Covalent...
02:04Polytene Chromosomes
Polytene chromosomes are giant interphase chromosomes with several DNA strands placed side by side. They were discovered in the year 1881 by Balbiani in salivary glands, intestine, muscles, malpighian tubules, and hypoderm of larvae Chironomus plumosus. Hence, these are also called "Salivary gland chromosomes." These are found in insects of the order Diptera and Collembola; in certain organs of mammals; and synergids, antipodes of flowering plants. Polytene chromosomes are also regularly...
01:23Ions, Molecules, and Compounds
Ions - When an atom participates in a chemical reaction that results in the donation or acceptance of one or more electrons, the atom becomes positively or negatively charged. This frequently happens for most atoms to have a full valence shell. This can happen either by gaining electrons to fill a shell that is more than half-full or by giving away electrons to empty a shell that is less than half-full, thereby leaving the next smaller electron shell as the new, full valence shell. An atom with...
01:08Covalent Bonds
Overview
When two atoms share electrons to complete their valence shells, they create a covalent bond. An atom's electronegativity—the force with which shared electrons are pulled towards an atom—determines how the electrons are shared. Molecules formed with covalent bonds can be either polar or nonpolar. Atoms with similar electronegativities form nonpolar covalent bonds; the electrons are shared equally. Atoms with different electronegativities share electrons unequally, creating polar bonds.
When two atoms share electrons to complete their valence shells, they create a covalent bond. An atom's electronegativity—the force with which shared electrons are pulled towards an atom—determines how the electrons are shared. Molecules formed with covalent bonds can be either polar or nonpolar. Atoms with similar electronegativities form nonpolar covalent bonds; the electrons are shared equally. Atoms with different electronegativities share electrons unequally, creating polar bonds.
01:26Alveoli and Alveolar Ducts
The respiratory zone of the human body, which stands in contrast to the conducting zone, comprises the structures that actively participate in the exchange of gases. The initiation of this zone is marked by the terminal bronchioles converging into respiratory bronchioles, the tiniest bronchiole classification. The respiratory bronchioles give way to the alveolar ducts that opens into a congregation of alveoli. Actively involved in gas exchange, alveoli resemble tiny sacs similar to clusters of...
01:30The Electrical Double Layer
In the region where two bulk phases meet, an intricate electric charge distribution arises due to charge transfer, ion adsorption, molecular orientation, and charge distortion. This complex distribution is commonly referred to as the electrical double layer.When a solid electrode interfaces with ions in an electrolyte solution, the speed of electron transfer dictates the rates of oxidation and reduction. The electrode acquires a charge through the escape of atoms into the solution as cations or...