C
Plants can’t communicate by moving or making sounds, as most animals do. Instead, plants produce volatile compounds, chemicals that easily change from a liquid to a gas. A flower’s sweet smell, for example, comes from volatile compounds that the plant produces to attract insects such as bugs and bees.
Plants can also detect volatile compounds produced by other plants. A tree under attack by hungry insects, for instance, may give off volatile compounds that let other trees know about the attack, In response, the other trees may send off chemicals to keep the bugs away- or even chemicals that attract the bugs’ natural enemies.
Now scientists have created a quick way to understand what plants are saying: a chemical sensor(传感器) called an electronic nose. The “e-nose” can tell compounds that crop plants make when they’re attacked. Scientists say the e-nose could help quickly detest whether plants are being eaten by insects. But today the only way to detect such insects is to visually inspect individual plants. This is a challenging task for managers of greenhouses, enclosed gardens that can house thousands of plants.
The research team worked with an e-nose that recognizes volatile compounds. Inside the device, 13 sensors chemically react with volatile compounds. Based on these interactions, the e-nose gives off electronic signals that the scientists analyze using computer software.
To test the nose, the team presented it with healthy leaves from cucumber, pepper and tomato plants, all common greenhouse crops. Then the scientists collected samples of air around damaged leaves from each type of crop. These plants had been damaged by insects, or by scientists who made holes in the leaves with a hole punch (打孔器).
The e-nose, it turns out, could identify healthy cucumber, pepper and tomato plants based on the volatile compounds they produce. It could also identify tomato leaves that had been damaged. But even more impressive, the device could tell which type of damage – by insects or with a hole punch – had been done to the tomato leaves.
With some fine tuning, a device like the e-nose could one day be used in greenhouses to quickly spot harmful bugs, the researchers say. A device like this could also be used to identify fruits that are perfectly ripe and ready to pick and eat, says Natalia Dudareve, a biochemist at Purdue University in West Lafayette, Ind. who studies smells of flowers and plants. Hopefully, scientists believe, the device could bring large benefits to greenhouse managers in the near future.
49. We learn from the text that plants communicate with each other by______.
A. making some sounds B. waving their leaves
C. producing some chemicals D. sending out electronic signals
第1题:
通信速度最快的总线是
A.LIN总线
B.CAN总线
C.FlexRay总线
D.MOST总线
第2题:
关于MOST网络的特点,以下描述正确的是:()
A.双向传输
B.使用两条光纤绞接在一起
C.传输速率介于LIN与CAN之间
D.MOST150速度可以达到150Mbit/S
第3题:
3、MOST总线与CAN总相比,对电磁干扰不敏感。
第4题:
汽车空调、后视镜、座椅等应用哪种总线进行数据传输
A.LIN总线
B.CAN总线
C.FlexRay总线
D.MOST总线
第5题:
2、奔驰W211车门控制单元连接的总线系统属于 。
A.CAN -B
B.CAN- C
C.CAN -D
D.MOST
第6题:
在车载网络系统中 CAN-B、CAN-C和MOST等总线通过 模块进行数据交换。