For the past decade, one of the most linguistically(语言学地) diverse places in the world, square mile after square mile, has been my home: Queens, New York. The soundtrack outside my door is extraordinary: On any given block, passing voices speak varieties of Polish, Ukrainian, Egyptian Arabic, Mexican Spanish, Puerto Rican Spanish, Dominican Spanish. and all the forms of New York City English they give rise to. 

As a person who studies languages, I can usually distinguish them from one another. but under stand only a part of what people are saying. 

Users of Seke, a language from five villages in Nepal with 700 speakers, live a subway ride away In certain stores, Albanians, Bosnians, Serbs, and Montenegrins all reunite, using the languages of the former Yugoslavia as if the country still existed. No group has a majority, or even 15 percent of the neighborhood, and most are at just 5 or 10 percent. English acts, for the most part, as a vital linguafranca(通用语). This last point is crucial, because a city can be a haven(避难所) for diversity but also an end point. 

My neighborhood has its signature sound, but there are several dozen others that are just as diverse each in a different way. These are the places where the Endangered Language Alliance, the nonprofit I co-direct, has recorded New Yorkers speaking more than 100 languages that the survey and other data sets say don't officially exist, and more than 700 in total. 

That linguistic portrait makes clear that early-2lst-century New York City is a last haven for endangered languages-ones that are being hounded out of existence elsewhere. And this deep linguistic diversity is among the least explored but possibly most important factors in New York's history and makeup. New York's soul can be found in the existence of these many, many languages, explaining New York's particular capacity for tolerance and its ability to " make room" for others. 

Princess culture is less about a princess lifestyle, and more about great-depth of character, serving as a beautiful reminder of worth—whether a girl is a princess or not. In Frances Hodgson Burnett's A Little Princess, Sara Crewe survived her many tragedies and hardships by remembering "I am a princess. All girls are… even if they aren't pretty, or smart, or young. They are still princesses. " Whether child or adult, all can benefit from the belief that no matter their circumstances, they always have value—that true self-worth goes beyond appearance or environment and is found deep within. No matter how difficult our circumstances are, princesses encourage us to remember our worth.

Spend much time with a four-year-old girl in the U. S and you will likely see some sort of princess play, whether it is dressing up, acting out stories, or playing with princess-themed toys. This particular type of pretend play is very important to children. Lindsey and Colwell found that children who regularly engage(参与)in pretend play have more positive emotions with peers(同龄人), score higher on emotional understanding, and are better at emotional regulation one year later. Research suggests that princess play specifically can lead to rich experiences for children as they expand on the stories of familiar characters.

Princesses also provide examples of "women who rule", showing women and girls that they can be accepted as the heroines of their own stories and lead with wisdom and maturity( 成熟). In other words, princesses inspire potential.

Adults often think of princesses in a negative way someone who is too proud or crazy about their appearance. But in children's imagination, the word "princess" allows them to think about what they can become. Maybe they won't save the world, but they will defend their values. Maybe they won't have the perfect figure, but they can develop the confidence to move beyond appearance.

Waste heat is a worldwide energy problem most people have probably never heard about. Every machine and power station, even renewable energy like wind and solar, creates heat that is simply lost in the atmosphere. Thankfully, scientists and engineers are devoted to capturing heat and transforming it into useful electricity.

Thermophotovoltaic devices (热光电设备) are one promising way to use this waste heat. University of Michigan engineers have created a precisely machined thermophotovoltaic cell that could be used to generate electricity from surplus renewable power. The cells would use heat stored in molten salt and turn it into electricity on demand, in a form that is much cheaper than batteries, say its creators.

One of the factors important to any device's thermoelectric efficiency is its material. If higher electrical energy can be created with smaller temperature differences, then the materials are said to have a high ZT value. And a new material created by scientists in Vienna has broken the ZT value world record.

Any new thermoelectric material has to have a distinct advantage, and research is identifying a number of promising products. Pyroelectric films (热电薄膜) are aimed at waste heat emitted at less than 100 degrees Celsius (212 F) and can generate electricity when a material is either heated or cooled.

Low-temperature generation includes computers and cars, making pyroelectrics particularly useful for squeezing more energy out of electronic systems.

Another relative advantage is inexpensive materials. More abundant elements like tin, selenium, and magnesium are cheap and abundant, with high ZT values when combined in the right way. Their use could lead to greener car engines and industrial facilities.

And when it comes to personal electronics, thermoelectric could eventually see off traditional charging hardware. Chinese researchers have built a wristband that gathers body heat to power a LED and may be able to power smartwatches or other mobile devices in the future.