Discovering the proper classification for each piece of household waste before throwing it out—and avoiding fines of up to 50,000 yuan—has become as simple as taking a photo thanks to the efforts of a group of young programmers.

They have applied speech and picture recognition technologies to apps and other smartphone services to guide Shanghai residents through China's first mandatory garbage-separation plan. The rules require every citizen and institution to classify waste into four categories-recyclables, kitchen waste, hazardous waste and residual waste—with a long list of items in each category. Previously, everything went into one dustbin, and the dramatic change has made many Shanghai residents worried. Many residents say they are struggling to master the details quickly.

To smooth the process and raise public awareness, Shanghai government launched a campaign featuring posters and TV programs introducing garbage-sorting techniques.

“It has become a lasting topic for my family's mealtime discussions,” 27-year-old Shanghai resident Fang Chengxiang said. He said they used the Internet to find out how to classify waste properly. “I would often Baidu the name if I got confused,” Fang said, referring to China's leading search engine.

Most of the apps and services, which began springing up last month in app stores, on messaging tool WeChat and mobile payment service Alipay, allow users to type in the name of waste to identify which category it belongs to.

One of the apps using speech recognition is What Garbage, whose downloads topped 130,000 in the first week after it was released early this month.

It was designed by zzz studio, a team made up of a programmer, an advertising art director and a visual designer. Since they all have 996 jobs—meaning they work from 9 am to 9 pm six days a week—the app was designed in what little spare time they have.

Liu Yiyi, 23, a member of the studio, said it was designed to help people through the transition period, and it especially helps people sort ambiguous items. Actually, Liu Yiyi added, as Chinese become accustomed to rules, people will use the apps less often.

Transport is undergoing a massive transformation so it can meet society’s demands for a low- carbon economy. Introducing electric vehicles (EV) and declining gasoline use are helping, but zero-carbon hydrogen can speed up both the transition (转变) and long-term decarbonization of transport.

In the US, transportation produces the largest share of all greenhouse gas emissions (排放) in the economy at 29%, according to the Environmental Protection Agency. More than 90% of transport fuel is petrol based, but if more vehicles used hydrogen, emissions of this kind would plummet.

However, hydrogen is not considered an ideal replacement for gasoline as an engine fuel for cars because it is harder to store safely. And while fuel cell electric vehicles (FCEVs) that turn hydrogen into electricity can compete with EV performance-and even out-compete them on range and refill time, extra energy is needed to produce the hydrogen needed for fuel. Also, finding investment for storage, pipelines and fuel stations is still a challenge for many nations.

Currently, governments worldwide are backing green hydrogen projects to reduce greenhouse gas emissions in heavy industries like freight (货运), steel, and energy storage. But hydrogen transport will need rapid production methods to create the fuel needed for the world’s road fleet.

Thankfully, research is advancing all the time. Nanoscale (纳米级的) thin films are applied to improving the chemical process to rapidly harvest hydrogen from the seawater. The same technology has been successfully used in solar power devices with higher efficiency-to-cost rates. Since hydrogen is the most abundant element in the universe and as seawater makes up about 96% of all water on Earth, there is a virtually limitless supply.

Even wastewater and solid waste can create green hydrogen. Researchers at Princeton University are using sunlight to separate hydrogen from industrial wastewater. Chemical plants that currently face high costs for cleaning wastewater could transform it into clean hydrogen supplies.

If you walk into a native plant nursery, you must feel defeated because all the little plants look similar. Now we have the shopping guide for you: a set of easy-to-carry flashcards that explain in brilliant color what those little plants will look like when they all grow up.

Native plants just aren't that easy to understand for traditional gardeners. “That's why staff at the Theodore Payne Foundation for Wild Flowers & Native Plants began creating some good information into the world of native plants," said Kitty Connolly. "Everybody needs to learn about natives if we're going to have them, in our future, but it's difficult to get information to everyone at once. We wanted something that would be useful to everyone. "

The group decided to create flashcards only about the size and shape of an iPhone 6. “You can take them apart and put them on a table to see how plants go with other plants. They don't replace a website or great books on the shelf; they're just easier to carry and use for planning, said Mike Evans. While the cards are very small, they include a lot of information. You can find how tall and wide a particular plant will grow, when it blooms, how quickly it grows, what birds and animals it attracts and how much water and sunlight it needs.

The cards don't include all native plants. They don't include milkweed, for example. But they are helpful for people to learn native plants.

The price of the cards is $ 17. They are only sold online. If people have the cards , they can more easily request the plants they want. The director said, “We create the cards with the hope that people can learn more about native plants and grow them."