TRAFFIC BOOST: The first extradosed bridge in Tibet Autonomous Region, the 1.28-km-long Ngaqen, opens to traffic on November 27 in Lhasa. Such bridges combine the structural features of a girder and cable-stayed bridge (LIU KUN)

Science Discover

Chinese scientists have observed hydrogen bonds through modified non-contact atomic force microscopy (AFM) for the first time in history, the National Center for Nanoscience and Technology (NCNST) announced on November 22.

Hydrogen bonds are fundamental to the most important molecules in nature. In particular, they are responsible for holding the two strands of the double helix that forms DNA together and many enzymes use them to catalyze reactions.

Although study of hydrogen bonds began in the 1850s, scientists had not been able to view them until now.

A group of scientists with the NCNST have worked on modifying equipment for five years so as to create the best AFM apparatus in the field, and their work has allowed scientists to accurately analyze the structure of hydrogen bonds and directly measure bond angles and lengths.

"As an analogy, we have seen people on the ground standing in line from space before, but now we see them hand in hand for the first time," said Qiu Xiaohui, one of the group's scientists, adding that the discovery has broad application prospects in the study of intermolecular interactions.

Qiu said that accurate measurement of hydrogen bonds not only helps researchers understand the bond interaction, but also has great significance in material science and pharmaceutical development.

U.S.-based Science Magazine published the research results in essay form on November 1.

Pilot Licenses

The Civil Aviation Administration of China (CAAC) announced on November 26 that it will ease requirements for obtaining private pilot licenses (PPLs), a move that should allow more Chinese citizens to fulfill their flying dreams.

The requirements for theory tests, practical tests as well as physical examinations will be loosened for those applying for a PPL, with previous standards being almost as high as those for acquiring commercial pilot licenses, according to a CAAC statement.

Under the new regulation, Chinese citizens aged 17 or above and with at least a junior high school education, will be eligible to apply for a PPL, which is only applicable for the flying of non-profit aircraft.

After they receive a certified report of their physical fitness, they will also have to go through 40 hours of theoretical studies and another 40 hours of flight training before they sit relevant tests. Passing the tests will win them a PPL, the statement said.

It added that those who have obtained a PPL can also become professional pilots by acquiring a commercial pilot license, but that will be based on their flying time as a private pilot and need higher levels of training.

The previous regulation concerning the acquisition of pilot licenses in China was released in 1996.