【推荐1】Solar power is one of the fastest growing sources of renewable power globally these years. Solar photothermal (光热) and solar photovoltaic (PV光伏)are both technical forms.

The thermal power station adopts the generation mode of “light--heat--electricity”. Thousands of heliostats (定日镜) reflect the sunlight to the surface of the heat absorber on the top of the solar tower. The concentrated sunlight is then used either directly as a source of heat, as in solar water heating, or to drive a heat cycle such as a Sterling Engine. PVs use semi-conductor technology to directly convert sunlight into electricity. The PV line is connected to the direct current (DC) distribution cabinet in parallel through the DC combiner box. After confluence (汇合), it is connected to the DC input end of the inverter to convert DC into alternating current (AC). The AC output end of the inverter is connected to the AC distribution cabinet and directly connected to the user side through the AC distribution cabinet.

Additionally, since solar thermal directly produces heat, it can store thermal energy into various media. Therefore, solar thermal can potentially generate power 24 hours a day. On the other hand, PVs only operate when the sun is shining, and must be coupled either with other power generation mechanisms to ensure a constant supply of electricity.

The scale of PV power generation can be large or small, ranging from thousands of watts to hundreds of megawatts, but photothermal power generation is typical economies of scale. With the increase of scale, the lower the power generation cost.

PV power generation is less limited by region, for the sun shines on the earth. Compared with other sources of renewable power, the PV system is safe and reliable as well as eco-friendly. Since it can be convenient for local power generation and power supply, you do not worry about consuming fuel or erecting transmission lines. A small PV power can be constructed in a short period with no noise or low pollution.

【推荐2】Artificial Intelligence (AI) has changed many industries and continues to advance at a rapid speed. From autonomous vehicles to voice assistants, AI is becoming an part of our daily lives. Let’s explore the evolution of AI and its impact on society.

The concept and development of AI date back to the 1950s and 1960s. Early researchers focused on creating machines that could copy human intelligence to perform tasks such as problem-solving and language processing. However, the limited computational power and lack of data held back progress.

In the 1990s and 2000s, machine-learning algorithms appeared, allowing computers to analyze large amounts of data. This breakthrough enabled AI systems to improve performance over time and make more accurate predictions (预测).

Deep learning belonging to machine-learning has gained attention in recent years. It involves training neural networks with layers of interconnected nodes to process large amounts of data. Deep learning has pushed forward advancements in image recognition, natural language processing, and autonomous systems.

AI has had a great impact on various industries. In healthcare, AI is used for diagnosing diseases and developing personalized treatment plans. In transportation, self-driving cars are becoming a reality. In customer service, chatbots provide round-the-clock assistance. However, the widespread adoption of AI also raises concern about job displacement and ethical(道德的)considerations.

【推荐1】Sometimes, when we talk to our dogs, they tilt (倾斜) their heads adorably to one side. Although it might suggest disbelief or confusion, the gesture could actually be a sign of concentration, according to a new study.

Researchers investigated how well 40 dogs of various species could memorize the names of different toys and then recall that information in order to retrieve (找回) specific toys in response to their owners’ commands. Most of the dogs weren’t able to learn the toy names, but seven (one died during the study) border collies (边境牧羊犬) showed extraordinary ability to do the job.

The scientists regarded that group as “gifted word learners”, and found that the seven collies had something in common: they all tilted their heads far more frequently than other dogs after hearing a command. The data showed that the gifted learners tilted their heads 43 percent of the time, while the other 33 dogs did the gesture just 2 percent of the time. “It seems that there’s a relationship between the success in retrieving a specific toy and frequent head tilts upon hearing its name,” said Shany Dror, an animal researcher at Eötvös Loránd University in Hungary.

The gifted dogs showed they could learn 12 new toy names in one week, and then remember those names for at least two months. And only the gifted dogs who performed well at the toy retrieval tests consistently tilted their heads after hearing a command. That led Dror’s team to conclude that the gesture is related to collies’ attempts to work out the meaning of a word.

Similar to the way humans are right- or left-handed, the gifted collies also tended to move their heads to just one side or the other. Their favored side stayed the same during the three experiments regardless of where the owners were standing. To the researchers, that consistency may be additional evidence that dogs tilt their heads when paying close attention to a test.

The so called “right-tilters” and “left-tilters” may be individual preference, which scientists want to investigate further.

【推荐2】We’re all born with a natural number sense. But some people’s number sense is better than others, and several studies published in 2013 suggest this inborn capacity, believed to be an essential building block for learning arithmetic (算术), can be improved with instruction.

In a study published in October, Brannon and colleagues from Johns Hopkins University showed 48 six-month-olds a series of dot arrays (点阵) ; the researchers inferred the babies’ ability to detect differences in the quantity of dots based on how long they spent looking at an array after it changed. As expected, some babies had a keener sense of quantity than others. Three years later, the researchers tested the same children’s math skills and found that those whose number sense at 6 months was keenest were most excellent at math at age 3, regardless of their overall intelligence.

But we’re not stuck with our inborn limitations. In a study published in August, Brannon and her colleague had 52 adult volunteers participate in a study examining whether improving number sense helps sharpen higher math skills. First, participants performed multi-digit arithmetic problems. Then half the group spent 10 hours estimating large quantities of dots in arrays; a control group had no such practice. Afterward, all participants completed arithmetic problems again. Researchers found that the math skills of volunteers who participated in the dots exercise improved significantly compared with those in the control group.

Other research, published in April, helps explain why some children respond to math tutoring better than others do. Stanford University scientists put 24 third-graders through an eight-week math-tutoring program. The kids’ math proficiency improvement ranged from8 to 198 percent, and was unrelated to IQ, memory and cognitive ability tests. But brain imaging showed that the children who benefited most had a larger hippocampus, a key memory area, and stronger neural (神经的) connections between the hippocampus and brain regions involved in long-term memory and habit-building.

“This gives us clues about the memory systems the brain uses to build knowledge,” says Stanford neuro-scientist Vinod Menon, the study’s senior author. The results, he says, could explain the origins of math learning disabilities and lead to improved educational programs for kids who struggle with math.