“One thing I enjoy about my job is that I can work on something that is actually active,” says Game McGimsey, an American volcanologist (火山学家). Part of his job includes keeping an eye on Alaska's many active volcanoes and giving people a heads-up when a volcano might erupt (喷发).

    Like most jobs in the sciences, volcanology requires a lot of education. McGimsey received an undergraduate degree in geology at the University of North Carolina, then landed an internship (实习期) with a geologist at the USGS (美国地质勘探局) whose area of expertise was volcanoes. After earning a graduate degree at the University of Colorado, McGimsey accepted a job with the USGS and has been with the Alaska Volcano Observatory for 25 years.

    Volcanoes can influence the world in ways we might not think about. For example, on Dec. 15, 1989, a 747 jetliner (a large airplane) flew through a thick ash (灰) cloud produced by Mount Redoubt, an Alaskan volcano that hadn't erupted in 25 years. The ash caused all four engines to die, and the plane's electronics went dead.

    “The plane was within several thousand feet of flying into the mountains below when the pilots got a couple of the engines restarted and landed safely in Anchorage,” McGimsey says. It cost nearly $80 million to repair the damage to the plane.

    Such situations show just how dangerous volcanoes can be. However, volcanologists know the risks and are prepared to protect themselves.

    “There is certainly a higher danger level in volcanology than some other jobs,” McGimsey admits. “We understand how serious the danger is, and we don't like taking unnecessary chances. We avoid getting too close to an erupting volcano, because it's not worth injury or death simply to get a rock or a photograph.”

    In the waters off Brisbane, Australia, a seven­foot­long sand tiger shark swims in pain. A two­foot­long spike sticks out of her side. It's a piece of fishing equipment that the shark ate carelessly. After traveling into her body, the spike punctured(刺) through the shark's stomach.

    A man swimming in the water notices the shark. Then, he warns Sea World Marine Park in the nearby town of Gold Coast. Sea World sends a 12­person team from its rescue center to where the shark was discovered in Moreton Bay Marine Park. Soon, they find her lying on the seafloor. "She'll die without help，"says Trevor Long, leader of the rescue center.

    Using an onboard crane(吊车), the rescuers move the shark into their boat's 13­foot­long tank(缸). Then Dr. David Blyde gives the shark pain medicine and performs an operation to remove the spike. After that, the team sails with the shark to Sea World 33 miles away. They place the fish in a 49­foot­long tank and wait to see if she gets better.

    To give the shark's stomach time to get better, she isn't fed for the first few days. A week after her operation, Long offers the shark a small, dead fish. The animal refuses to eat. But days later when he drops another fish into her tank, the shark enjoys her meal. By now the shark's wounds are getting better.

    Two weeks after her rescue, they take the shark back to the boat and return her to Moreton Bay Marine Park. As the fish is lowered by the crane to the water's surface, two rescuers jump into the ocean and guide her into the sea. From the boat, Long watches her swim away." The shark has another chance," Long says.

    If you were an exchanged student in New York City, one day your math teacher gave you following questions as your homework, please write down your answers.

    Ⅰ.A company sold a product for α dollars in 1990. The price of the product would increase by 2.5% every year.

    Ⅱ.A man needs to make 3 curtains. The cloth which is used to make curtains sells for $8.00 per meter and can be purchased only by the full（完整的） meter. The length of cloth required for each curtain is 1.6 meters.

    Ⅲ.A pet store sells only dogs and cats. In March, the store sold twice as many dogs as cats. In April, the store sold twice the number of dogs that it sold in March, and three times the number of cats that it sold in March.

    I began cycling in 2004 when I was a poor student. It was dangerous, sure, but cycling is the fastest, cheapest point-to-point form of transport in Melbourne. I own a car now, but that's just for transporting the baby or groceries.

    I hate driving. So it's been quite encouraging watching the growth in cyclist numbers over the past decade. It is said that over 10,000 cyclists enter the CBD (Central Business District) each day, taking pressure off public transport. But as more people take to cycling as a way of transport, the number of cyclists seriously injured or killed keeps increasing. And that is a sign that our infrastructure (基础设施) is still not good enough.

    Melbourne was once a dream for cyclists—flat, long, wide roads, with plenty of paths along rivers. Now, cycling can be deadly, with roads taken up by cars. I have a friend who broke her back and was lucky to escape death and others with broken bones. In my time riding, I've been forced off the road by a truck, cut off by four-wheel drives, and told to get off the road. Drivers are a particularly rude to cyclists. And that's a sign of exactly one thing: inadequate infrastructure.

    We shouldn't need to be taught how to coexist in the same narrow space. Drivers and cyclists should be kept apart. Designing bike paths so riders are channelled between moving cars and parked cars is deadly. All it takes is one daydreaming driver to fling open the door and you are gone. That's what happened to the young university student James.

    This year, there are to be new cycling lanes (车道) built on Glen Road, where James died in 2010. But these lanes are not safe. Cyclists must still pass between two rows of cars.

    It was dinner time for the Rangers, a group of mostly Indigenous (本地的) Australians who had spent a long day cleaning up the polluted beaches of the continent's northern coast. Soon they would be eating freshly caught fish and seafood cooked under the stars on an open fire, as their ancestors did.

    The Rangers are of more than 100 Indigenous groups spread across Australia who have taken on the job of protecting the land of their forefathers. In Arnhem Land, they are the protectors of 3,300 square miles of land and sea. They comb the beaches by hand, picking up as much rubbish as possible. The task is very difficult as each day it delivers waves of new rubbish.

    For the Rangers, cleaning the beaches is more than a vacation. For a people whose culture is strongly tied to the land, protecting the environment is equal to preserving their history.

    However, colonization forcefully broke their connection to the land generations ago. Indigenous people were displaced and their cultural practices outlawed. Tens of thousands of years of traditional land management ended, and as a result many parts of the country now face serious disasters from invasive plant and animal species, bush fires and land mismanagement.

    In recent years, the government has restored more than 20 percent of Australia's land to Indigenous owners. Since 2007, the Indigenous Rangers Organizations have been at work protecting this land.

    Luck, one of the few non-Indigenous employees working with the Rangers, said the combination of old and new techniques and an appreciation for the culture of Indigenous workers has been critical to the program's success.

    "You are working with staff who see the world different to you, so there is a much higher focus on the cultural aspects of work and life," he said.

    "Being a ranger is a source of confidence. You feel strong," said Terence, a senior ranger. "Here we still live on the land. The culture is still alive."

With the summer heat becoming increasingly unbearable over the years due to climate change,the cooling load in the summertime has also been on the rise.Insulation(隔热) is currently the main solution for blocking heat from entering a building,but by applying an additional material that can delay heat penetration(渗透),it can prevent the indoor temperature from rising and in turn lower the cooling load of the building.

A research team in Korea has developed a new material for building walls that can help reduce the penetration of heat from the outside.The team directed by Dr.Sarng Woo Karng from KIST revealed that they have successfully done it through building walls by applying a phase change material(PCM).One of the most common types is paraffin oil,which is used to make candles.

A solid PCM absorbs heat as it transforms into a liquid phase,so by using a case to hold it when it is in a liquid phase without causing any leakage(渗漏),it is possible to apply them to a building wall to block heat from entering inside.

The problem,however,is that the PCM turns into liquid starting from the outermost layer,and the parts that are hot move upward,while the parts that are still relatively cool move downward.Thus,while the upper part may have completely melted,the lower part will have not,and as a result,heat will penetrate into the building through the area where the PCM is in a liquid phase.In the end,the PCM becomes ineffective in controlling the indoor temperature and is rendered useless.

Dr.Karng's team addressed the non-uniform phase change with bubble injections.Injecting bubbles into the bottom part of the PCM enabled uniform circulation(流动)of the PCM in a liquid phase.Dr.Karng said,"We expect that the insulating wall using the PCM bubble generator used in this study will contribute to reducing the amount of energy used to heat or cool a building.Insulation techniques using the PCM help reduce heat penetration,in combination with the building insulating material,and it can also be used as the outer walls of zero-energy buildings."