Breakthroughs in science and technology are paving the way for modern cities to support bigger populations. Now, we see the most exciting urban innovations to show you exactly how they'll improve your city's infrastructure(基础设施).

Lighting Up The Night

    Anthony Di Mari dreamed up an electric tree to help irrigate public parks and light them at night. These electric trees contain a special infill (填充物) that collects water from rainfall. The water is then distributed through a shallow underground irrigation system with the help from the trees' swaying movement. An electric motor turns energy from the waving of the artificial trees into electricity, which is used to light up the trees' outer LEDs.

Thinking Outside The Box

    As more people flock to urban areas, city planners will need to get increasingly creative about how to satisfy residents' health and transportation needs within decreasing available space. One way to achieve this is by updating infrastructure to support biking and walking by building suspended(悬浮的) roundabouts like hovering in the Netherlands. By lifting bicycle and pedestrian traffic above busy roadways, cities can significantly decrease over-crowded traffic condition.

Waving Hello To Clean Energy

    Cities that don't receive enough sunlight may find an attractive alternative in wave power. Since ocean waves rarely experience disruption(中断), electric engines driven by their clockwork push-and-pull can reliably provide power throughout the year. Further, thanks to advances in wave power technology, engineers have been able to move wave power engines farther offshore, where the waves pack the most punch, making the engines extremely efficient. So in the future, heavily populated coastal cities may use wave to meet their energy needs.

    Dolphin or not a dolphin? That is the question! You see, there are several types of dolphins. Some are saltwater dolphins while others are river dolphins.

    "What are the 32 types of dolphins?" When people are asking the question, they are actually referring to the saltwater dolphins in oceans and seas. The river dolphins living in fresh water are not included in these species. But what would be the answer in this case if we ask. "Dolphin or not a dolphin?" The answer would obviously be yes. River dolphins still belong to the dolphin family.

    Among the 32 types of dolphins do not actually wear the word "dolphin" in their names, such as the tucuxi, while others actually have the word "whale" as part of their names even if they are not whales but in fact, belong to the dolphin family, for example, the melon-headed whale and the killer whale. So what would be the answer to the question "Dolphin or not a dolphin?" in these cases? It would be yes. All these species do belong to the dolphin family.

    Another question that people ask is. "Are the sea animals that perform at aquariums(水族馆)all dolphins?" So ,it always seems to come back to the question, "Dolphin or not a dolphin?" Well the answer is no in this case. The sea animals that perform there are not all dolphins. The beluga which people tend to think belong to the dolphin family because they show what seems like a smile, like most dolphins, are in fact a species of the whale family.

    Now that you read these facts about dolphins, you probably realize that certain sea animals may appear to be part of the dolphin species and that others seem to be part of the whale family but in either case, it is not obvious and can be surprising when you identify a sea animal as being a dolphin or not a dolphin. That is the question ！

    Dogs are our best friends. That's especially true after a disaster, such as an earthquake. When buildings fall down, search and rescue dogs help find trapped people. Dogs' amazing noses can pick up the smell of survivors. Now scientists have developed an electronic tool that does the same thing. It's taking smell detection(探测) to a whole new level.

    The new invention is a sort of electronic nose, which can detect extremely low levels of many compounds(化合物) from people's skin. This isn't the first time engineers have developed such an object. Earlier models, however, have been bulky and expensive. They could not detect low levels of target compounds either. The new one is inexpensive and small enough to fit inside hand-held equipment.

    The electronic nose can detect extremely slight smell of more than one compound at the same time. "Being able to do this, in such a small object, is the significant discovery," says Sotiris E. Pratsinis, Professor of Process Engineering&Materials Science at the Swiss Federal Institute of Technology in Zurich. His team tested it in special spaces. They were like the small spaces where people might be trapped. Chemicals given off by the volunteers built up inside. The electronic equipment detected those compounds at unbelievably low levels.

The results were good news for the research team. But they may be not for our four-legged friends, who could soon be out of a job. "Ideally, this technology could replace search and rescue dogs," Pratsinis says.

    Stephen Taylor, an electrical engineer, agrees that the new technology has some benefits over dogs. Still, he thinks it may be too soon to have our trusty friends retire. He suspects, "I foresee that such an object could add to the fine work done by the dogs." Taylor also pointed out some potential limitations of the new invention. "E-noses are useful, but can be very likely to be affected by unstable readings and interruption," he says.

    "I'm the smartest kid in class." We all want our kids to be self-confident, but unrealistic perception(认知) of their academic abilities, a new study finds, damage a child's relationship with others in the classroom: The more one student feels unrealistically superior(更好的) to another, the less the two students like each other.

Katrin Rentzsch of Bamberg University in Germany first became interested in the effects of such self-perception when she was studying how people became labeled as nerds(书呆子). "I really got interested in the question of whether it's OK to boast(吹嘘) about achievements," she says.

    This line of thinking led her towards something psychologists call "self-enhancement" －when a person feels unrealistically superior to someone else. So Rentzsch and her colleague Michela Schroder-Abe decided to take a closer look at how such self-enhancement affects relationships, so they turned to the eighth-grade classroom, somewhere they could measure differences between actual academic performance, and social popularity. The 358 students came from 20 eighth-grade classes in schools in southeast Germany.

    The researchers asked each student to rate their classmates, in terms of their likability and of their feelings of academic superiority. They then compared those ratings with the students' grades in math, physics, German and English. Importantly, they conducted the analysis at two different social levels: "habitual"－the way people act in general, and "relationship"－the way someone acts around a specific individual.

    In future work, Rentzsch would like to look at these effects on adults, perhaps specifically in team work. She's also interested in self-enhancement beyond academic achievements, for example physical attractiveness. And another question to explore is why students overestimate their academic abilities. Perhaps it is because of too much praise from their parents or teachers.

    Scientists Diego Kersting and Cristina Linares have found that some coral species are able to recover from harmful warming events through a unique survival strategy (策略)—known as "rejuvenescence" (新生)—among corals in the Mediterranean Sea. The findings represent some rare good news for corals around the world, which are facing numerous severe threats—most notably, climate change.

    "The main threats are climate change, overfishing, pollution and coastal urbanization," Kersting said. "But currently, climate change is probably the one causing the most coral cover declines. Warming stresses corals up to a point that may cause death. Some corals bleach (白化) before dying. Other corals do not bleach but die directly." He went on, "Our findings are significant because this survival strategy was only known from fossil corals that existed hundreds of millions of years ago. It is the first time that it has been found in a living coral. Thanks to our findings, we know now that some corals are able to recover, but unfortunately this is not enough in the current climate change context."

    For their research, Kersting and Linares monitored 243 colonies of the endangered reef-building coral Cladocoracaespitosa in Spain's Columbretes Islands Marine Reserve over 16 years, starting in 2002. The monitoring revealed that Cladocoracaespitosa in the Mediterranean uses rejuvenescence to cope with warming events. This process involves the polyps — or the individual coral animals in a colony—shrinking inward and abandoning their skeletons (骨骼) during warm periods, before rejuvenating at a later point. "What happens is that some polyps in a coral colony—sometimes just one— reduces completely its dimensions and partially retreats from its skeleton," Kersting said. "Once the stressful event is over, the shrunken or rejuvenated polyp recovers its size and builds up a new skeleton. Eventually, it begins to reproduce itself through budding and begins to cover the dead colony surfaces."

    He continued, "The results were very surprising because I started to observe colonies that were dead years ago, that were showing living parts many years after their death."

Humans' overconsumption of resources is a leading contributor to global climate change, says University of Arizona researcher Sabrina Helm. Therefore, it's increasingly important to understand the choices consumers make and how those decisions affect the health of a planet with limited resources. In a new study, published in the journal Young Consumers, Helm and her colleagues explore how materialistic values influence pro-environmental behaviors in millennials, who are now the nation's most influential group of consumers.

The researchers focused on two main categories of pro-environmental behaviors: reduced consumption, which includes actions like repairing instead of replacing older items; and "green buying," or purchasing products designed to limit environmental impacts. The researchers also looked at how engaging in pro-environmental behaviors affects consumer well-being.

More materialistic participants, the researchers found, were unlikely to engage in reduced consumption. However, materialism did not seem to have an effect on their likelihood of practicing "green buying." That's probably because "green buying," unlike reduced consumption, still offers a way for materialists to fulfill their desire to get new items, Helm said.

Study participants who reported having fewer materialistic values were much more likely to engage in reduced consumption. Consuming less was, in turn, linked to higher personal well-being and lower psychological suffering. Green buying—which may have some positive environmental effects, although to a smaller degree than reduced consumption—was not found to improve consumer well-being, Helm said.

The take-home message for consumers: "The key is to reduce consumption and not just buy green stuff. Having less and buying less can actually make us more satisfied and happier," Helm said. "If you have a lot of stuff, you have a lot on your mind," she said. "For example, it requires maintenance and there's a lot of burdens of ownership, and if you relieve yourself of that burden of ownership, most people report feeling a lot better and freer."

Helm and her colleagues additionally looked at how materialism affects millennial consumers' proactive financial behaviors, such as budgeting and saving. Examining financial behaviors alongside pro-environmental behaviors provides a picture of how young adults proactively deal with resource limitations in two contexts: environmental and financial, Helm said.

As expected, Helm and her colleagues found that those who reported having more materialistic values engaged in fewer proactive financial behaviors than their less materialistic counterparts (对应的人). The researchers also found that, consistent with previous studies, proactive financial behaviors were associated with better personal well-being, life satisfaction and financial satisfaction, as well as lower psychological suffering.

Understanding how materialistic values impact consumer behaviors, and how those behaviors in turn affect personal and environmental well-being, is important, Helm said. However, she acknowledges that for many consumers, shifting behaviors to be more financially proactive and consume less will be challenging.