2 . On paper, hydrogen（H2）looks like a dream fuel. Coal, oil, and natural gas produce carbon dioxide, which warms the earth when burned, Hydrogen produces pure water. Hydrogen packs more energy into less space than a battery（but certainly less than petrol）. Also, empty tanks（燃料箱）can be refilled with hydrogen much faster than refilling empty batteries with electricity.

While in practice, things are trickier. Storing a meaningful amount of hydrogen gas requires pressing it several hundred-fold. Changing it into the liquid form is another option, but it should be cooled to-253C. Both processes require a heavy and strong tank. While a 700 bar tank is acceptable for a city bus or a truck, adapting it for use in small vehicles is very difficult because the pressure during refilling would be too great.

The solution? Powerpaste.

A German team of researchers, led by Marcus Vogt, have come up with an interesting "powerpaste", which can store hydrogen energy at atmospheric pressure, ready for release when needed. It is so named because it comes in tubes and looks like toothpaste（牙膏）, not in its traditional form of gas.

The main ingredient（原料）of the paste is magnesium hydride, a substance that reacts with water to form hydrogen. The escaped hydrogen can then be directed into a fuel cell, where it reacts with oxygen from the air to produce electric power.

Refueling is very simple, as instead of going to a filling station, drivers and riders can simply replace an empty tube with a new one and refill the water tank.

Given that powerpaste only begins to break down at temperatures of around 250℃ it remains safe even when a vehicle stands in the baking sun for hours.

However, we will have to be patient. Just because researchers have succeeded in developing a new fueling way does not mean that we can expect to see such vehicles on the road anytime soon. It will indeed be several years before this concept is turned into reality.

Beijing Daxing Airport is Finally Open

Beijing Daxing International Airport (PKX), also known as Beijing New Airport, is the biggest airport in the world. It is also the second international airport of Beijing along with Beijing Capital International airport. Daxing Airport is located in Daxing District (the southern suburbs of Beijing). Its location was selected after thorough analysis. With a 46km-distance from Tiananmen Square, a 67km-distance from Beijing International Airport and a 26km-distance from Langfang City Center, Daxing Airport aims to become the main airport hub of the serving area. It is expected to handle up to 45 million passengers per year by 2021 and reach an outstanding 100 million in the future.

Daxing Airport was called “Starfish” because of its impressive shape. There is a huge terminal building (航站楼) covering a 700,000m² area while the ground transportation centre extends to 80,000m². For the time being, Daxing Airport has four runways and 79 airport stands. The 4 runways’ size is impressive while the airport stands are suitable both for one twin-aisle (双通道) and two single-aisle planes. Eventually, the airport will have 7 runways in total and will be able to serve about 620,000 flights annually.

The airport’s design is pioneering. Its terminal building is the impressive outcome of the collaboration between ADP Ingeniérie (ADPI) and the architecture team of Zaha Hadid (ZHA) who tragically passed away in 2016. Then, in August 2018, Hong Kong design studio Lead 8 undertook the design of the new commercial terminal which is expected to respond to every passenger’s needs.

Daxing Airport was designed to show high respect to environmental protection. Besides, to simplify passenger procedures, there are only less than 600 meters between checkpoints and gates and a minimum waiting time for baggage claim. Furthermore, the designers paid great attention to the convenient ground transportation system of the airport. High-speed and intercity trains, metro and public buses will connect the new airport to Beijing city and other major areas in a fast and efficient way.

4 . Is traffic a big problem where you live? Increased cycling may be the answer. Where are the best places to live and cycle? A new report lists the best bike-friendly cities around the world.

Top of the list is Amsterdam, the bike capital of the world. An incredible 40% of all traffic movements are by bicycle. There’s an extensive network of safe, fast and comfortable cycle routes. Copenhagen, the city of bikes, is a city where 32% of workers cycle to work because it’s fast and easy. Berlin is another European city that’s great for cycling. The city has about 80 kilometers of bike lanes, and 50 kilometers of pavement paths. Cycling accounts for 12% of total street traffic.

Barcelona has been praised for its cycle service “Bicing”. This was introduced in March 2007. It’s a bicycle service that allows users to take bicycles from any of the 100 stations spread around the city. Later, they can leave them at any other bike station inside the urban area of the city. The city has created a “green ring” that surrounds the city area of Barcelona with a bike path. There are 3,250 parking spaces for bikes at street level at present. Barcelona City is also building a new underground car park for bicycles.

The UK has its cycle-friendly cities too. Bristol is the birthplace of “Sustrans” —the cycle-route charity which was formed 30 years ago. One of their projects was turning an old rail line between Bristol and Bath into a bike route. Other bike-friendly cities in the UK include Cambridge and York Cambridge is an old city but has still managed to build good cycle infrastructure (基础设施), and cyclists are considered at every stage of any new developments.

Bicycle is a most popular means of transportation in China. Nowadays, riding a bicycle is also a good way to support low-carbon living. Beijing can be one of the best bike-friendly cities in China. There are many riding routes in Beijing for outdoor-lovers to explore. Cyclists can get close enough to experience the history and culture of Beijing, including the Forbidden City, Drum Tower, the Water Cube, the Bird’s Nest, Hutong etc.