【推荐1】International airline Emirates says it successfully flew a Boeing 777 on a test flight with one engine running on a mixture of “sustainable” fuel.

The test flight took place Monday and lasted about an hour. “The plane took off from Dubai International Airport and then headed out into the Persian Gulf before returning to the airport. It was powered by two General Electric engines. One ran on the sustainable mixture. The other was powered by traditional airplane fuel to ensure safety. Emirates’ chief operating officer, Adel al-Redha, called the flight “a milestone moment for Emirates and a positive step for our industry”. The flight demonstrated the airline’s desire to deal with one of the industry’s biggest problems, carbon pollution releases related to air travel.

The mixture included fuel provided by Neste, a Finnish company, and US-based fuel maker Virent. Virent says it uses plant-based sugars to make the compounds needed for sustainable jet fuel. Neste’s fuel is made from vegetable oils and animal fats. Those fuels cut the release of heat — trapping carbon dioxide burned off by engines in flight. Airline flights release only one-sixth the amount of carbon dioxide produced by cars and trucks, the Washington-based World Resources Institute reports. However, airplanes are used by far fewer people per day than road vehicles. This means flying has a higher per-capita (人均) release of carbon emissions. But experts have noted that fuels considered sustainable can be three times or more the cost of traditional jet fuel. This added cost is likely to be passed onto flyers if sustainable fuels became more commonly used across the industry.

Airplane and engine manufacturers have been designing more environmentally-friendly versions in recent years. The general goal is to produce less-polluting engines to reduce fuel emissions in an effort to help limit the effects of climate change.

【推荐1】One of the things that we expect from the ocean is is deep blue color that reflects the sky. Scientists at UC San Diego Institution of Oceanography along with scientists at the University of Washington have been experimenting with dyeing (染) the ocean at San Diego beach pink. What could they possibly be up to?

This is being done for a study that examines how freshwater outflows are combining with the ocean surf zone. The experiment is called Plumes in Nearshore Conditions (PiNC).“I’m excited because this research hasn’t been done before and it’s a unique experiment,” said Sarah Giddings, a coastal oceanographer leading the study. “The aim is to understand how freshwater interacts with waves, since it is usually warmer than ocean water and more buoyant (有浮力的).”

The freshwater is dyed pink so that the team can easily keep track of it when freshwater is added to the seawater. The dye is environmentally friendly and is then spotted as it makes progress in the water. It is tracked by sensors on poles that are located along the sand as well as by drones (无人机). There’s also a jet ski with a fluorometer that tracks the light that is given out from the pink dye. The sensors outside of the surf zone record the height of the waves, ocean currents and temperature. There are three planned dye releases as of now, and researchers are hoping that this pink dye experiment will help them record more about how pollutants travel in the ocean water through these additions of freshwater.

Giddings explained: “We’re bringing together different people with different expertise, such that I think it’s going to have some great results and impacts. We’ll combine results from this experiment with an older field study and computer models that will allow us to make progress on understanding how the dyed freshwater spread.”

【推荐2】Swimmers can drown in busy swimming pools when lifeguards fail to notice that they are in trouble. Now a company has developed an artificial intelligence system called Poseidon that sounds the alarm when it sees someone in danger of drowning.

When a swimmer sinks towards the bottom of the pool, the new system sends an alarm signal to a poolside monitoring station and a lifeguard’s pager. In trials at a pool in Ancenis, near Nantes, it saved a life within just a few months, says Alistair McQuade, a spokesman for its maker, Poseidon Technologies.

Poseidon keeps watch through a network of underwater and overhead video cameras. AI software analyses the images to work out swimmers’ trajectories(轨迹). To do this reliably, it has to tell the difference between a swimmer and the shadow of someone being cast onto the bottom or side of the pool.

It does the same with an image from another camera viewing the shape from a different angle. If the two projections are in the same position, the shape is identified as a shadow and is ignored. But if they are different, the shape is a swimmer and so the system follows its trajectory.

To pick out potential drowning victims, anyone in the water who starts to descend(下降)slowly is added to the software’s “pre-alert” list, says McQuade. Swimmers who then stay immobile on the pool bottom for five seconds or more are considered in danger of drowning. Poseidon double-checks that the image really is of a swimmer, not a shadow, by seeing whether it obscures(使模糊) the pool’s floor texture when viewed from overhead. If so, it alerts the lifeguard, showing the swimmer’s location on a poolside screen.

The first full-scale Poseidon system was officially opened at a pool in High Wycombe, Buckinghamshire. One man who is impressed with the idea is Travor Baylis, inventor of the clockwork radio. Baylis runs a company that installs swimming pools—and he was once an underwater escapologist(脱身杂技演员) with a circus. “I say full marks to them if this works and can save lives,” he says.

【推荐3】It would be much more convenient if electric cars could be recharged wirelessly. Some electric toothbrushes and other small devices, such as mobile phones, can already be topped up in this way using a process called electromagnetic induction (电磁感应). This employs some kind of electrical current flowing through a coil (线圈) to create a varying magnetic field, which then generates another current in a second coil placed alongside it, which is used to recharge a battery.

As users of electric toothbrushes and phones will know, device and charger must be both close to each other and precisely adjusted for this process to work. That is tricky to achieve with an electric car, which sits above the ground and requires higher levels of energy transfer.

These problems are being overcome with advances like that made by WiTricity, a firm based near Boston. This company was founded in 2007 to commercialize the work of Marin Soljaèi and his colleagues at the Massachusetts Institute of Technology. Dr Soljaëi knew, in theory, that by having the transmitting and receiving coils resonate (共振) at the same frequency it should be possible to transfer greater amounts of energy over longer distances. In practice, he sought to commercialize the system to large companies, such as BMW.

An advantage of wireless recharging is what WiTricity’s boss calls “power snacking”. This is topping up the battery when a car is stationary for a short time. The company provides systems to recharge taxis in this way while they wait in line, and to do the same for electric buses at bus stops. It is also possible to charge vehicles while they are on the move. That might make sense in places where vehicles often queue up, such as at airports.

【推荐1】Many people are aware of the beauty of a solar eclipse (日食), but are surprised to learn that lunar eclipses are often just as impressive. While a total solar eclipse lasts only for a few minutes and can be seen only in a small area of a few square kilometres, a total lunar eclipse can last for several hours and can be seen over much of the planet. Therefore, the beauty and stability of lunar eclipses make them a favourite of both amateur and professional photographers.

Lunar eclipses generally occur two or three times a year, and are possible only when the Moon is full. When we see the Moon, we are actually seeing sunlight reflect off the surface of the Moon. When the Earth passes between the Moon and the Sun, however, the Earth’s shadow falls on the Moon, and a lunar eclipse occurs.

The type of lunar eclipses—total, partial, or penumbral (半影的)—that occurs depends on both how much of the Moon passes through the Earth’s shadow and through which part of the shadow it passes. A penumbral eclipse occurs when the Moon passes through the Earth’s outer shadow. This type of eclipse is brief and frequently goes unobserved by anyone but astronomers. By contrast, total and partial eclipses occur when all or part, respectively, of the Moon passes through the umbra (本影) of the Earth. These eclipses are quite easy to see and are widely observed.

Unlike solar eclipses, lunar eclipses are safe to watch. Solar radiation that occurs during an eclipse of the sun can cause a form of burns of one’s eyes know as eclipse blindness. In fact, the only way to safely view a solar eclipse is using specially designed equipment. However, since the Moon’s light is reflected sunlight, it is completely safe to watch a lunar eclipse without any special equipment, although a pair of binoculars (双筒望远镜) can certainly help the viewer appreciate the beauty of this phenomenon.

【推荐2】China came 49th in a ranking of English proficiency (熟练) in 112 non-English speaking countries and regions produced by Swedish educational company, EF Education First.

In the company’s 2021 English Proficiency Index, China scored 513 out of 800 points, a decrease (降低) in its ranking last year, when it came 38th out of 100 non-English speaking countries with a score of 520 points.

EF Education First has produced the report for 11 years and this year’s report analyzed data from 2 million non-native English speakers, who were tested on their ability to understand written and spoken English.

The average age of participants was 26. Ninety-four percent were under 60, and 53 percent were women.

Adults from Netherlands were ranked as the best non-native English speakers with a score of 663, followed by those from Austria (641), Denmark (636), and Singapore (635). Yemen had the lowest score, with just 360 points.

Within China, Hong Kong was ranked first at 545, followed by Shanghai at 543, Beijing at 523, Tianjin at 520 and Taiwan at 519.

Global average English proficiency has not changed significantly since last year and none of the countries listed has experienced a significant decline in score—meaning a more than 20-point decrease.

The addition of 12 new countries, as well as clustering (聚集) in the middle of the index, caused a larger than usual reshuffling (重新排序) in the rankings.

Jean Liu, executive vice-president and chief corporate affairs officer at EF China, said the world expects China to play a more important role in the post-pandemic era and English will become more important for development as the country further opens up to the outside world.

She added that English proficiency in China has seen steady improvement over the last decade, and China’s educational reform and development strategy serves as an example for others trying to improve national levels of English proficiency.