Let's Get 7 in IELTS

Trees may be able to protect themselves from forest fires by serving as living batteries—housing small devices, which would measure temperature and humidity and broadcast the data from tree-to-tree.

Current Forest Service fire sensors are spread widely, and gaps in the network can miss localized temperature and humidity changes. Researchers at MIT have proposed a solution to those gaps—using the trees themselves to power a web of additional sensors. The scientists, a group of students and teachers from MIT’s Center for Biomedical Engineering, figured out that trees carry an electric charge due to a difference in acidity between the tree and the soil it sits in.

Batteries need to be replaced, but trees don’t, meaning the network would sustain itself, saving costs to maintain and recharge sensors and allowing for a much larger and more sensitive monitoring grid. The group's results were published in the journal PLoS ONE, and they’ve already started a commercial company to develop the sensors that can harness that tree-power. According to their commercial website, they’ve developed a converter to power these weather sensors, which “parasitically harvests metabolic energy from any large plant without significantly harming it.” They plan to test the network this spring.

broadcast

vt.
1. 廣播,播送
2. 廣為散播,傳佈
3. 播(種)
vi.
1. 廣播,播放
2. 參加廣播演出;發表廣播演說
a.[Z][B]
1. 廣播的,播音的
2. 散佈的;撒播的
n.
1. 廣播;廣播節目
2. 散佈;播種
ad.
1. 經廣播
2. 廣泛地;散佈地

acidity

n.
1. 【化】酸性;酸度
2. 酸味
3. 【醫】胃酸過多
4. (言語的)尖刻

英漢雙向醫學詞典
【拉】酸度；酸性

sustain

vt.
1. 支撐;承受,承擔
2. 維持,供養;支援
3. 支持,鼓舞
4. 忍受,禁得起
5. 遭受,蒙受
6. 【律】確認,認可
7. 證實,證明
8. 扮演

harness

n.[C][U]
1. 馬具,挽具
2. 挽具狀帶子;降落傘背帶;保險帶;安全帶
vt.
1. 給...上挽具;套(馬)[(+to)]
2. 治理,利用;控制,駕馭

parasitically 

ad.
1. 寄生地;寄生物引起地

harvests

n.
1. 收穫;收穫季節[C][U]
2. 收成,產量[C]
3. 結果;後果;成果[S]
vt.
1. 收割;收穫
2. 獲得,得到
vi.
1. 收割莊稼
metabolic  

a.
1. 變化的;新陳代謝的