文章来源:未知 文章作者:meng 发布时间:2010-04-14 00:48 字体: [ ]  进入论坛

In an electrifying1(令人振奋的,惊人的) first, Stanford scientists have plugged in to(对……很感兴趣) algae2(海藻) cells and harnessed a tiny electric current. They found it at the very source of energy production – photosynthesis3(光合作用) , a plant's method of converting sunlight to chemical energy. It may be a first step toward generating "high efficiency" bioelectricity(生物电) that doesn't give off carbon dioxide as a byproduct(副产品) , the researchers say. "We believe we are the first to extract electrons out of living plant cells," said WonHyoung Ryu, the lead author of the paper published in the March issue of Nano Letters. Ryu conducted the experiments while he was a research associate for mechanical engineering professor Fritz Prinz.

The Stanford research team developed a unique, ultra-sharp nanoelectrode made of gold, specially4 designed for probing inside cells. They gently pushed it through the algal cell membranes6(细胞膜) , which sealed around it, and the cell stayed alive. From the photosynthesizing cells, the electrode collected electrons that had been energized7 by light and the researchers generated a tiny electric current.

"We're still in the scientific stages of the research," said Ryu. "We were dealing8 with single cells to prove we can harvest the electrons."

Plants use photosynthesis to convert light energy to chemical energy, which is stored in the bonds of sugars they use for food. The process takes place in chloroplasts(叶绿体) , the cellular9 powerhouses that make sugars and give leaves and algae their green color. In the chloroplasts, water is split into oxygen, protons(质子,氢核) and electrons. Sunlight penetrates10 the chloroplast and zaps the electrons to a high energy level, and a protein promptly11 grabs them. The electrons are passed down a series of proteins, which successively capture more and more of the electrons' energy to synthesize(合成,综合) sugars until all the electron's energy is spent.

In this experiment, the researchers intercepted12(截取,拦截) the electrons just after they had been excited by light and were at their highest energy levels. They placed the gold electrodes in the chloroplasts of algae cells, and siphoned off(吮吸) the electrons to generate the tiny electrical current.

The result, the researchers say, is electricity production that doesn't release carbon into the atmosphere. The only byproducts of photosynthesis are protons and oxygen.

"This is potentially one of the cleanest energy sources for energy generation," Ryu said. "But the question is, is it economically feasible(可行的,合算的) ?"

Ryu said they were able to draw from each cell just one picoampere(微微安培) , an amount of electricity so tiny that they would need a trillion cells photosynthesizing for one hour just to equal the amount of energy stored in a AA battery. In addition, the cells die after an hour. Ryu said tiny leaks in the membrane5 around the electrode could be killing13 the cells, or they may be dying because they're losing out on energy they would normally use for their own life processes. One of the next steps would be to tweak(扭,用力拉) the design of the electrode to extend the life of the cell, Ryu said.

Harvesting electrons this way would be more efficient than burning biofuels, as most plants that are burned for fuel ultimately store only about 3 to 6 percent of available solar energy, Ryu said. His process bypasses(忽视,绕开) the need for combustion14(燃烧,氧化) , which only harnesses a portion of a plant's stored energy. Electron harvesting in this study was about 20 percent efficient. Ryu said it could theoretically reach 100 percent efficiency one day. (Photovoltaic光电的  solar cells are currently about 20-40-percent efficient.)

Possible next steps would be to use a plant with larger chloroplasts for a larger collecting area, and a bigger electrode that could capture more electrons. With a longer-lived plant and better collecting ability, they could scale up the process, Ryu said. Ryu is now a professor at Yonsei University in Seoul, South Korea.


1 electrifying f2081dbc620a5b326b713cef8349d30e     
v.使电气化( electrify的现在分词 );使兴奋
  • The dancers gave an electrifying performance. 舞蹈演员们的表演激动人心。
  • The national orchestra gave an electrifying performance of classic music. 国家交响乐团举行了一次古典音乐的震撼性演出。 来自辞典例句
2 algae tK6yW     
  • Most algae live in water.多数藻类生长在水中。
  • Algae grow and spread quickly in the lake.湖中水藻滋蔓。
3 photosynthesis A2Czp     
  • In apple trees photosynthesis occurs almost exclusively in the leaves.苹果树的光合作用几乎只发生在叶内。
  • Chloroplasts are the structures in which photosynthesis happens.叶绿体就是光合作用发生的地方。
4 specially Hviwq     
  • They are specially packaged so that they stack easily.它们经过特别包装以便于堆放。
  • The machine was designed specially for demolishing old buildings.这种机器是专为拆毁旧楼房而设计的。
5 membrane H7ez8     
  • A vibrating membrane in the ear helps to convey sounds to the brain.耳膜的振动帮助声音传送到大脑。
  • A plastic membrane serves as selective diffusion barrier.一层塑料薄膜起着选择性渗透屏障的作用。
6 membranes 93ec26b8b1eb155ef0aeaa845da95972     
n.(动物或植物体内的)薄膜( membrane的名词复数 );隔膜;(可起防水、防风等作用的)膜状物
  • The waste material is placed in cells with permeable membranes. 废液置于有渗透膜的槽中。 来自辞典例句
  • The sarcoplasmic reticulum is a system of intracellular membranes. 肌浆网属于细胞内膜系统。 来自辞典例句
7 energized bb204e54f08e556db01b90c79563076e     
v.给予…精力,能量( energize的过去式和过去分词 );使通电
  • We are energized by love if we put our energy into loving. 如果我们付出能量去表现爱意,爱就会使我们充满活力。 来自辞典例句
  • I am completely energized and feeling terrific. 我充满了活力,感觉非常好。 来自辞典例句
8 dealing NvjzWP     
  • This store has an excellent reputation for fair dealing.该商店因买卖公道而享有极高的声誉。
  • His fair dealing earned our confidence.他的诚实的行为获得我们的信任。
9 cellular aU1yo     
  • She has a cellular telephone in her car.她的汽车里有一部无线通讯电话机。
  • Many people use cellular materials as sensitive elements in hygrometers.很多人用蜂窝状的材料作为测量温度的传感元件。
10 penetrates 6e705c7f6e3a55a0a85919c8773759e9     
v.穿过( penetrate的第三人称单数 );刺入;了解;渗透
  • This is a telescope that penetrates to the remote parts of the universe. 这是一架能看到宇宙中遥远地方的望远镜。 来自《简明英汉词典》
  • The dust is so fine that it easily penetrates all the buildings. 尘土极细,能极轻易地钻入一切建筑物。 来自辞典例句
11 promptly LRMxm     
  • He paid the money back promptly.他立即还了钱。
  • She promptly seized the opportunity his absence gave her.她立即抓住了因他不在场给她创造的机会。
12 intercepted 970326ac9f606b6dc4c2550a417e081e     
拦截( intercept的过去式和过去分词 ); 截住; 截击; 拦阻
  • Reporters intercepted him as he tried to leave the hotel. 他正要离开旅馆,记者们把他拦截住了。
  • Reporters intercepted him as he tried to leave by the rear entrance. 他想从后门溜走,记者把他截住了。
13 killing kpBziQ     
  • Investors are set to make a killing from the sell-off.投资者准备清仓以便大赚一笔。
  • Last week my brother made a killing on Wall Street.上个周我兄弟在华尔街赚了一大笔。
14 combustion 4qKzS     
  • We might be tempted to think of combustion.我们也许会联想到氧化。
  • The smoke formed by their combustion is negligible.由它燃烧所生成的烟是可忽略的。
TAG标签: energy current cells plant