BEIJING, March 30 (Xinhua) -- The following are the highlights of China's science news from the past week:

-- Chinese researchers have built an open database on Circular RNAs, laying the groundwork for studies on the novel class of RNAs with important biological implications.

-- A group of scientists have discovered a fossil bird dating back about 110 million years, which is the first ever found to have an unlaid egg in its abdomen.

-- Researchers from China and Germany have developed a way to improve microalgae's tolerance to high levels of carbon dioxide, offering new perspectives on cutting carbon emissions and even future exploration of Mars.

-- China has released 11.25 million spectra of celestial objects acquired by the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) to astronomers worldwide.

-- Researchers from Tianjin University said that they had developed ultra-high-energy fluorinated carbon materials, the key technology to realizing ultra-energy storage.

-- Chinese scientists have discovered a certain protein that is essential in mammals' sperm development.