Batteries can power anything from small sensors to large systems. While scientists are finding ways to make them smaller but even more powerful, problems can arise when these batteries are much larger and heavier than the devices themselves. University of Missouri(MU) researchers are developing a nuclear energy source that is smaller, lighter and more efficient.

    “To provide enough power, we need certain methods with high energy density (密度)”，said Jae Kwon, assistant professor of electrical and computer engineering at MU. “The radioisotope (放射性同位素) battery can provide power density that is much higher than chemical batteries.”

    Kwon and his research team have been working on building a small nuclear battery, presently the size and thickness of a penny, intended to power various micro/nanoelectromechanreal systems (MNEMS) Although nuclear batteries can cause concerns, Kwon said they are safe.

    “People hear the word 'nuclear' and think of something very dangerous,” he said, “However, nuclear power sources have already been safely powering a variety of devices, such as pace-makers, space satellites and underwater systems.”

    His new idea is not only in the battery's size, but also in its semiconductor(半导体). Kwon's battery uses a liquid semiconductor rather than a solid semiconductor.

    “The key part of using a radioactive battery is that when you harvest the energy, part of the radiation energy can damage the lattice structure(晶体结构) of the solid semiconductor,” Kwon said, “By using a liquid semiconductor, we believe we can minimize that problem.”

    Together with J. David Robertson, chemistry professor and associate director of the MU Research Reactor, Kwon is working to build and test the battery, In the future, they hope to increase the battery's power, shrink its size and try with various other materials. Kwon said that battery could be thinner than the thickness of human hair.

    Snoring(打鼾) is noisy breathing during sleep. It is a common problem among all ages and it influences about 90 million American adults. People most at risk are males and those who are overweight, but snoring is a problem of both genders, although it is possible that women do not present this complaint as frequently as men.

    Snoring is often the loud or harsh sound that can occur as you sleep. You snore when the flow of air makes the tissue in the back of your throat vibrate(颤动) as you breathe. The sound most often occurs as you breathe in air, and can come through the nose, mouth or both two organs. It can occur during any stage of sleep.

    About half of people snore at some point in their lives. Snoring is more common among men, though many women snore. It appears to run in families and becomes more common as you get older. About 40 percent of adult men and 24 percent of adult women are habitual snorers. Men become less likely to snore after the age of 70.

    Sleeping on your back may make you more likely to snore. You may snore when your throat or tongue muscles are relaxed. And substances(物质) that can relax these muscles may cause you to snore. These include alcohol, muscle relaxants and other medicine.

    Snoring can be a nuisance to your partner and anyone else nearby. You may even snore loudly enough to wake yourself up. Though, in many cases people do not realize that they snore. Snoring can also cause you to have a dry mouth when you wake up.

    Light snoring may not disrupt your overall sleep quality. Heavy snoring may be connected with a risk factor in the heart disease, stroke and many other health problems. So never take it lightly.

    Unemployment in the United States is still high at 6.7％. But for job seekers, especially those with college educations, researchers say finding a job can be as easy as logging(登录)on to a computer. It used to be that looking for a job meant hurrying around, knocking on doors and turning to ads. But that's changing, thanks to the Internet. A new report says, for college graduates, looking for a job is getting easier. More than 80 percent of the jobs are available online.

    At the height of the depression(萧条), in the U. S. the highest unemployment rate was 10％, just a little more than two million jobs were being posted each month. But as the recovery takes hold, the job picture looks increasingly bright.

    That's great news for Hamilton. Only once has he ever applied in person for a job at a shopping mall. He said, "I think my generation—the idea of going door to door, out knocking and saying, hey are you hiring? —like that—doesn't exist anymore…those days are gone. Just go online.''

Kim Dancy recently graduated with a master's degree in Public Policy. She found her dream job as an education policy researcher. But she says finding the perfect job online takes a lot of perseverance. She said, "It can be really frustrating and it takes a long time, but if you applied for enough positions and really do your homework you will get somewhere.

    The report's findings suggest careers in Science, Technology, Engineering and Math provide the greatest opportunities, with salaries that range between $30 to $45 an hour. But for maximum income and satisfaction, workers must be prepared to move and change jobs at least every five years.

    Ever walked to the shops only to find, once there, you've completely forgotten what you went for? Or struggled to remember the name of an old friend? For years we've accepted that a forgetful brain is as much a part of aging as wrinkles and gray hair. But now a new book suggests that we've got it all wrong.

    According to The Secret Life of the Grown-up Brain, by science writer Barbara Strauch, when it comes to the important things, our brains actually get better with age. In fact, she argues that some studies have found that our brain hits its peak between our 40s and 60s — much later than previously thought.

    Furthermore, rather than losing many brain cells as we age, we keep them, and even produce new ones well into middle age. For years it's been assumed that brain, much like the body, declines with age. But the longest, largest study into what happens to people as they age suggests otherwise.

    This continuing research has followed 6,000 people since 1956, testing them every seven years. It has found that on average, participants performed better on cognitive (认知的) tests in their 40s and 50s than they had done in their 20s. Specifically, older people did better on tests of vocabulary, verbal memory (how many words you can remember) and problem solving. Where they performed less well was number ability and perceptual speed — how fast you can push a button when ordered. However, with more complex tasks such as problem-solving and language, we are at our best at middle age and beyond. In short, researchers are now coming up with scientific proof that we do get wiser with age.

    Neuroscientists are also finding that we are happier with aging. A recent US study found older people were much better at controlling and balancing their emotions. It is thought that when we're younger we need to focus more on the negative aspects of life in order to learn about the possible dangers in the world, but as we get older we've learned our lessons and are aware that we have less time left in life: therefore, it becomes more important for us to be happy.

Amid the coronavirus outbreak, the U. S. Department of Homeland Security recommends having at least a two - week supply of water and food.

Potatoes

Shelf life: 2 to 5 weeks if stored in a cool, dry, dark place

Yukon Gold, red, and fingerling potatoes will last from two to three weeks. Larger white potatoes can last for three to five weeks. Sweet potatoes have about the same shelf life. Don't store them next to onions, however. The two might go together well in cooking, but raw, each gives off gases and moisture that might cause the other to spoil faster.

Tea

※Shelf life: 6 to 12 months past "sell - by" date

Dried tea leaves, whether loose (in a sealed container) or in teabags (in an unopened box) can easily last a year or more if they're not subjected to damp or humidity. However, the tea does tend to lose flavor over time.

Peanuts

● Shelf life: 1 to 2 months

Peanuts in their shell, especially when kept cool and dry, are perfectly happy in the cupboard for as long as two months.

Canned fruits and vegetables

● Shelf life: 1 to 2 years past "sell – by" date

Canning is an extremely efficient means of preserving food. Generally speaking, if canned foods aren't subjected to extreme heat, their contents should stay good for two years or more. Be aware, however, of dented cans or those with swollen tops, which may indicate the presence of bacteria inside.

San Francisco Fire Engine Tours

San Francisco Winery Tour 

Running: February 1st through April 30th 

This delicious tour goes through the city on its way to Treasure Island where we will stop at the famous Winery SF. Here you can enjoy 4 pours of some of the best wine San Francisco has to offer. (Included in ticket price)

Departing from the Cannery(罐头食品厂): Tour times upon request 

Duration: 2 hours 

Price: $90

Back to the Fifties Tour 

Running: August 16th through August 31st 

This tour transports you back in time to one of San Francisco's most fantastic periods, the 1950s! Enjoy fun history as we take you through San Francisco for a free taste of ice cream. 

Departing from the Cannery: 5: 00 pm and 7: 30 pm 

Duration: 2 hours 

Price: $90

Frightening Halloween Tour 

Running: October 10th through October 31 st

Join us for a ride through the historical Presidio district. True fire gear(服装)is provided for your warmth as our entertainers take you to some of the most exciting parts of San Francisco. 

Departing from the Cannery: 6: 30 pm and 8: 30 pm 

Duration: 1 hour and 30 minutes 

Price: Available upon request

Holiday Lights Tour 

Running: December 6th through December 23rd 

This attractive tour takes you to some of San Francisco's most cheerful holiday scenes. True fire gear is provided for your warmth as you get into the holiday spirit. 

Departing from the Cannery: 7: 00 pm and 9: 00 pm 

Duration: 1 hour and 30 minutes 

Advance reservations(预订)required.