An exhibition showcasing Cambodia's ancient Khmer civilization dating back 1,000 years drew large crowds on its opening day at the Shanxi Museum in Taiyuan, capital of north China's Shanxi Province, as it offers Chinese visitors a rare chance to experience the richness of Angkor heritage up close.
The exhibition, which opened on Friday and will run until October 7, features over 130 pieces or sets of cultural relics from the National Museum of Cambodia, including Buddhist sculptures, architectural elements, and ceramics dating from the Funan Kingdom to the Angkor Empire.
"The majority of Chinese people are very familiar with Cambodian culture, especially with Angkor temple. But to see such beautiful objects, especially the masterpiece like over there, a masterpiece sculpture, is a very rare opportunity," said Ly Vanna, Secretary of State of Cambodia's Ministry of Culture and Fine Arts.
The exhibition showcases 1,000 years of Cambodian art and the long-standing cultural exchanges between China and Cambodia.
"The occasion provides Chinese people more opportunity to learn and observe Khmer civilization, and then also to recall the relationship between these two countries historically," Ly said.
"What impressed me most was the balustrade carved with Garuda and Naga. The piece has a strong visual impact. I've learned about Garuda from the classic Chinese novel 'Journey to the West', so I was particularly eager to see it in person. It brought back fond memories and made the exhibition more engaging," said Zhang Xiaoyan, a student at Taiyuan Normal University.
Spanning nearly 2,000 years, the China-Cambodia friendship is a longstanding bond. Having supported Cambodia's cultural heritage preservation with technology and expertise in recent decades, China now sees this exhibition exemplify the two countries' growing cultural cooperation, as the museum highlights.
Expo showcasing Cambodia's Khmer civilization draws crowds of Chinese visitors
Major breakthroughs by Chinese scientists have laid the foundation for a future where space-based solar power stations are capable of wirelessly transmitting energy to Earth and spacecraft, though significant engineering problems remain.
A research team from Xidian University in northwest China's Shaanxi Province has made significant progress on the Sun Chasing project, or "Zhuri" in Chinese. The team has developed a ground-based test system for wireless power transmission that can charge multiple moving targets at the same time.
In recent tests, the system achieved a wireless power transmission efficiency of 20.8 percent from direct current to direct current over a distance of 100 meters. It delivered 1,180 watts of power. The team has also built a wireless charging system for drones. In a test, a drone flying at 30 kilometers per hour was able to receive 143 watts of stable power from 30 meters away.
A space solar power station works exactly as its name suggests: a huge array of solar panels placed in orbit. It would collect sunlight in space, where the sun always shines, and then convert that energy into microwaves or lasers to beam down to Earth or directly to satellites and spacecraft. This could address two significant issues: supplying uninterrupted power for space missions and alleviating energy shortages on the ground.
"The construction of space solar power stations could become a major undertaking in the future. One potential benefit is access to a virtually unlimited power supply. Because energy can be collected continuously in space 24 hours a day, electricity could be supplied on an uninterrupted basis," said Fan Guanheng, an associate professor at the School of Mechano-Electronic Engineering at Xidian University.
"Secondly, it could reduce our dependence on fossil fuels, thereby lowering carbon emissions and helping protect the environment. Thirdly, it could support the development of charging infrastructure in space and enable wireless microwave charging for spacecraft, changing the way power is supplied to space vehicles," the professor added.
In 2018, the research team launched the first phase of the Sun Chasing project to build a ground test system. By June 2022, they had completed the world's first full-link, full-system ground validation system for a space solar power station. Now, the team has moved to phase two. The goal now is to solve the challenges of generating high power in space and transmitting it efficiently over long distances.
According to Duan Baoyan, an expert at Xidian University and an academician of the Chinese Academy of Engineering, recent breakthroughs include improving the efficiency of solar energy collection and conversion, increasing the precision of microwave beam control to reduce energy loss, and making the transmitting and receiving antennas smaller and lighter, which is critical for space application.
The team has also solved the problem of how to power multiple moving targets at once using a single transmitter. This means that in the future, one space power station could potentially supply electricity to several satellites or ground vehicles at the same time, Duan said.
Despite the advances in ground-based validation, a series of technical challenges must still be overcome before the technology can be deployed in space.
"The first issue that needs to be addressed is the adaptability of components to the space environment, as conditions in space are completely different from those on Earth, including radiation exposure and extreme temperatures. Another challenge involves the deployment and retraction design of transmitting and receiving antennas. We also need to develop thermal management systems to cope with extreme temperatures and temperature fluctuations in space. These are all areas where further breakthroughs are needed," said Qian Sihao, an associate professor at the School of Mechano-Electronic Engineering at Xidian University.
"We have now completed the development and validation of a ground-based test system, and our next step is to carry out in-orbit wireless microwave power transmission," Fan said.
With ground validation complete, the team now turns its attention to overcoming the harsh realities of space, aiming to demonstrate in-orbit wireless power transmission and bring the vision of orbital solar energy closer to reality.
Space-to-earth solar power moves closer to reality although hurdles remain: scientists
