The brain of an insect isn't very big. But insects are somehow still able to make lots of important decisions. Bees, ants and roaches(蟑螂) build hives(巢穴)with thousands of workers doing specialized work. The jobs are done without a head or even a plan. How do insects manage this?
To solve the mystery, scientists in Belgium spent months building robotic roaches and then putting them among real roaches. The final goal of the research is to find out how the simple behavior of individuals gives rise to a collective decision. The roach is a good starting point for trying to answer the big question because its social system is simple enough for scientists to study.
The first step was to build robots that real roaches would accept as their own. Although the robotic roaches don't look much like the real thing, they have similarities with them in three key ways: they naturally head toward dark areas, they are influenced by the behavior of other roaches, and even more importantly, they smell like roaches.
The next step was getting the robotic and real roaches to work together on common tasks. In experiments, the robots would collectively head towards a dark place, copying the behavior of natural roaches. That got the researchers wondering: if you program the robotic roaches to go woward the lighted place, would the real roaches follow, going against their natural instincts.(本能) ?
They will – it turned out. Many of the real roaches followed the robots to a lighter shelter. But influence turned out to be a two- way street. On occasion, the real roaches were able to override the programming of the robot roaches and get them to turn into dark hiding places. Being social creatures, both the robotic and natural roaches were paying attention to and following the example set by others.
In theory, it would be possible to create a robot that could influence collective decision-making in humans. To do this, researchers would have to invent a robot that people would accept. Fortunately, the technology isn't there yet.
With the development of modern science and technology, the functions of cellphones have changed greatly. The only difference may be that they fit in your pocket and you pay by the minute to use them. Some of the things a cellphone can do for you will be available this year:
Surf at speed
Cellphones that let you use the Web have been around for years. So, what's new? Well , faster third-generation (3G) networks that let you surf at anywhere. Possible choices are from IJG Electronics VX 8000 and Motorola V1150.Listen as you go.
There is no doubt that it is about to change. Sony Ericsson's new W8001 can hold around 150 songs in its 500 MB memory. And Samsung's SPH-V5400 even comes with a l. 5 GB hard drive. Mobile phones may eventually replace miniMP3 players, especially for teens. Say cheese.
Camera cellphones are not new either but most of them have limitations: around l- megapixel (百万像素 ) . However new technology has made 2-megapixel units more common ,and 3-megapixel units are showing up soon. Some 2-megapixel models, like Sony Ericsson's K7501, offer limited zoom and focus controls. Portable TV.
You say you like "watching TV"? That's what Samsung MMA700 wants to give you. The new model lets users watch popular TV programmes~ for a fee. Other choices are Nokia's 6620, Sanyo's MM740 and NEC's N940.
The above are just a handful of what you ' ll see in the coming months. Further down the road, your mobile phone may play a host of other roles, such as mobile credit card, position locator and so on. So what is there that a cellphone can't do?
A. The NEC model lets you watch public TV - no fee.
B. Without a cellphone, you can do nothing in your daily life.
C. Nowadays, new cellphones are much cheaper than old ones.
D. Today's do-it-all mobiles have a lot in common with the computer.
E. This then allows a carrier to send video, music, and games to your phone.
F. Others, like LG's recent A7110, can even capture 30 minutes of full-motion video.
G. The problem with most cellphone MP3 players is that they hold only a handful of songs.
注意: 1.每处错误及其修改均仅限一词；2.只允许修改10处, 多者（从第11处起）不计分。
Failure is common in our life. No one can avoid them. When we fail in doing something, we often feel very depressing. Sometimes failure can make us lose hearts. So no one is willing to fail. On the contrary, success can bring us sense of pride. If one enjoys his continuous success in his career, he will have confidence to himself. Therefore, failure is the mother of success. A failure doesn't mean one can never be successfully. Those who are always afraid failure will never succeed. In a word, as long as we can get some lessons and experiences from our failure, we'll be sure to succeed.
A team of engineers at Harvard University has been inspired by Nature to create the first robotic fly. The mechanical fly has become a platform for a series of new high-tech integrated systems. Designed to do what a fly does naturally, the tiny machine is the size of a fat housefly. Its mini wings allow it to stay in the air and perform controlled flight tasks.
“It's extremely important for us to think about this as a whole system and not just the sum of a bunch of individual components (元件),” said Robert Wood, the Harvard engineering professor who has been working on the robotic fly project for over a decade. A few years ago, his team got the go-ahead to start piecing together the components. “The added difficulty with a project like this is that actually none of those components are off the shelf and so we have to develop them all on our own,” he said.
They engineered a series of systems to start and drive the robotic fly. “The seemingly simple system which just moves the wings has a number of interdependencies on the individual components, each of which individually has to perform well, but then has to be matched well to everything it's connected to,” said Wood. The flight device was built into a set of power, computation, sensing and control systems. Wood says the success of the project proves that the flying robot with these tiny components can be built and manufactured.
While this first robotic flyer is linked to a small, off-board power source, the goal is eventually to equip it with a built-in power source, so that it might someday perform data-gathering work at rescue sites, in farmers' fields or on the battlefield. “Basically it should be able to take off, land and fly around,” he said.
Wood says the design offers a new way to study flight mechanics and control at insect-scale. Yet, the power, sensing and computation technologies on board could have much broader applications. “You can start thinking about using them to answer open scientific questions, you know, to study biology in ways that would be difficult with the animals, but using these robots instead,” he said. “So there are a lot of technologies and open interesting scientific questions that are really what drives us on a day to day basis.”
—What a pity！Stella _______ here to see you.
学 生 | 安全隐患多（ 体育运动损伤，交通事故，食物中毒……） |
注意安全, 多学点急救知识 | |
一人安全, 全家幸福 | |
校 长 | 校园安全,师生共同重视 |
严禁校园骑车; 教学区内,不得进行球类运动 | |
上下楼梯, 靠右慢行 | |
教室无人,确保窗关门锁 | |
上学及回家路上遵守交通规则 |
On December 12th, 2009, our school held a flag-raising ceremony in the playground with the theme “For your safety, for your life!”
