Mogao Grottoes is located at the western end of the Hexi Corridor along the ancient Silk Road in Dunhuang, China. Until now, most mural paintings at Mogao Grottoes have been dated by directly referring to the mural texts or historical documents. However, some are still left with the creation era (年代) uncertain due to the lack of reference materials or the disagreement of art experts.

The drawing style of mural paintings was changing throughout history and can be learned and quantified through painting data. A new dating method has been developed by encoding (编码) the drawing styles using visual codes learned through deep learning. This new method successfully discovered the creation era of six mural paintings at Mogao Grottoes. This new research work is led by Qingquan Li from Shenzhen University.

With the help of experts from Dunhuang Academy, seven mural paintings from two grottoes (No. 205 and No. 206) were chosen as subjects for this dating research.

To reveal the creation era of these paintings, Qin Zou, a researcher from Wuhan University, collected 3,860 mural paintings from 194 different grottoes with confirmed creation-era labels. To find the visual codes that can identify the era in these paintings, the authors constructed a deep convolutional neural network (卷积神经网络) and classified (将……分类) these painting images into the right eras. Based on the classification model, a dating method was built and applied to date the seven paintings.

Six of the new dating results were approved by experts from Dunhuang Academy. “These dating results are correct and the method is great,” said Mr. Hui-Min Wang, a distinguished expert from the Archaeological Institute of Dunhuang Academy.

“To the best of our knowledge,” wrote the researchers, “this work represents the first account of a scientific and quantitative manner to support the era prediction and reduce the uncertainties in dating ancient paintings by using deep learning.”

Imagine that you are in a remote village somewhere with no medical clinic. 【小题1】 Once the doctors get to you, they examine you and take blood samples, but they won’t be able to help you until they take the samples back to the hospital to find out what is wrong. 【小题2】 Thanks to engineer Andy Ozcan, many people may never be in this situation. He has invented an app that turns your mobile phone into a diagnostic (诊断的) tool.

Ozcan’s invention is important because it is very accurate and easy to use. In many remote places, even if doctors have microscopes and other instruments to help them make diagnoses, there may still be other problems. Many doctors, for example, don’t have enough training to correctly interpret what they see. 【小题3】 With Ozcan’s mobile phone app, health workers can take a special photo of a blood sample and send it to a central computer at a hospital. The computer will then automatically interpret the photo and send a diagnosis back in a few minutes.

【小题4】 His technology only requires a mobile phone and an Internet connection. As more than four billion people already have mobile phones, the cost of establishing the diagnostic system is fairly low.

By inventing a medical tool that uses existing technology—mobile phones, Ozcan has developed a medical tool that is both practical and economical. Therefore, it can be used effectively almost anywhere. 【小题5】

Paying with your palm

Your palm（手掌）could soon be your ticket to a concert, thanks to Amazon One. On Sept 14, Amazon, a tech giant from the United States, announced that it is bringing Amazon One, a palm recognition technology, to music places as a replacement for physical tickets and apps. People just need to wave their hands over a piece of equipment outside the place to connect their palm to a ticketing account. Then they can use their palm to get into other shows and events at the place.

Catching CO₂ from air

Carbon dioxide（CO₂）is the main kind of greenhouse gas. It is usually the result of human activities, like driving cars and flying airplanes. Now, Swiss company Climeworks has created a machine called Orca to help catch CO₂. From its base in Iceland, Orca catches CO₂ from the air and keeps it 1, 000 meters underground. Orca can catch 4, 000 tons of CO₂ each year-around the same amount of CO₂ emissions that 870 cars give off per year.

Creating starch in a lab

Starch（淀粉）is the most important part of human food. Scientists at the Tianjin Institute of Industrial Biotechnology of the Chinese Academy of Sciences have created starch using CO₂, hydrogen（氢）and electricity, according to a study published in the journal Science on Sept 24. Lab tests show that synthetic（合成的）starch is about 8.5 times more efficient than starch produced by traditional agriculture. “There are many industries that can benefit from this technology.” Ma Yanhe, the author of the study, told China Daily.