【推荐2】A new keyboard can tell whether you are its owner. The keyboard records information about the typing pattern and sends it to a computer program. The program then checks to see if the typing pattern and sends it to a computer program. The program then checks to see if the pattern matches the right user, If not, an alarm sounds, and the computer locks the typist out. It locks out anyone else, even if than person knows password. What’s more, this device needs no batteries. It harvests all the person knows your password. What’s more, this device needs no batteries. It harvests all the energy it needs from the action of your typing. Besides, the keyboard is also self-cleaning and the keys are free of damage from water, oil and dirt.

The keys of the new keyboard are made of the same inexpensive plastic that might be found on any other standard keyboard. But instead of being smooth, the keys have millions of tiny plastic nanowires（纳米线）on their surface area to every key, increasing the gffective contact area between the plastics and fingers. This ensures that there’s enough power to run the keyboard as someone types.

Liming Dai, a scientist, did not work on the new keyboard, but he thinks the design could be important in getting better performance from a variety of devices. “It could also be applied to a touch screen, for instance,” Dai says. “Then smartphones and notepads could harvest energy from the action of someone typing or drawing.”

“Future work might make the keyboard even more useful,” Dai adds. “A later design might build tiny capacitors（电容器）onto the nanowires,” he suggests. Capacitors are little devices that temporarily store electric charges. Those might then LEDs to light a Keyboard in the dark.

Zhonglin Wang is a co-designer of the new keyboard. His team has build a working model of the keyboard. “If a company decides to fund（投资）its production, this keyboard could be in stores in as little as two years,” says Wang.

【推荐3】Have you noticed that as time goes on and technology advances, things seem to keep getting smaller and smaller? That’s especially true with that machine we call the “computer.”

What exactly is a computer? Webster’s Collegiate Dictionary defines a computer as “a usually programmable electronic device that can store, retrieve (检索), and process data.” Others think a computer as anything that transforms information in a meaningful way.

For thousands of years, people have tried to improve their lives by inventing machines to make certain tasks easier. Some people believe a simple mechanical device called an “abacus” was one of the earliest forms of a computer. Ancient people used the device to perform simple calculations (计算).Archaeologists (考古学家) have found evidence that the ancient Greeks used the abacus as early as the 5th century B.C.

Modern computers were developed much more recently. The first modern electronic computer—known as the Electronic Numerical Integrator and Computer or ENIAC—became operational in 1946. Weighing more than 30 tons, ENIAC took up as much space as 1,800 square feet. Since then, computers have become much smaller and much more powerful. While ENIAC could perform 5,000 addition problems per second, many of today’s laptop computers weigh just a few pounds and can perform several billion operations per second.

Today’s computers keep getting smaller and smaller. Large desktop computers gave way to laptops. Laptops have developed into a wide variety of even smaller computing devices, such as netbooks and tablet computers. Many people even carry computers with them everywhere they go. Smartphones, or cellphones, fit easily into a pocket and allow their users to make telephone calls, surf the Internet and conduct business.

So what’s the smallest computer available today? As of 2015, the smallest computer is just one cubic millimeter. However, today’s computer manufacturers are constantly producing newer and smaller models at a rate too fast to keep up with. Whatever is the smallest today will probably be replaced with something even smaller tomorrow!