New Progress in Physics Reported in Physical Review Letters

A research team of the Institute of Physics, CAS recently made significant progress in the study of the method for detecting the nano-molecular structure under the leadership of Prof. Gao Hongjun. They found that when studying the nano-molecular structure with x-ray, it is necessary to consider the initial- and final-state effects. Discoveries in the research can be correctly understood and comprehended only by closely connecting experimental measurements with the first-principle calculations. This is a new input to the traditional approach of measuring nano-molecular structure with x-ray. Relevant result was published in the Physical Review Letters. According the reviewer, this work reconsiders a widely used experimental method from a brand new physical perspective and addresses a bit problem existing in the related experiments and theoretic researches. Moreover, it also provides important foundation and directions to the understanding of similar experiment results in the future. Meanwhile, the work is of great significance in terms of serving as reference and direction to the design and protection of the molecular electronic devices working under X-Ray exposure.

New Step in LAMOST Project
MA Sub-mirrors Manufactured

On? Dec. 27, 2006，thirty MA submirrors (including six spare ones) manufactured by the Nanjing Institute of Astronomical Optics & Technology (NIAOT), CAS passed the acceptance check. The average value of RMS for these submirrors is 12.45nm (between 8.02--18.01nm), which has surpassed the requirement in the contract. The success is a significant milestone for the LAMOST project, signaling an important step forward. LAMOST optical system consists of two pieces of segmented mirrors – a reflecting Schmidt corrector MA at the northern end, a spherical primary mirror MB at the southern end and a focal plane in between. NIAOT completed all the research and development work in October 2006 and has now finished the installation of all the optical mirrors mounted on the two large segmented mirrors.

The project has created two significant achievements: 1) non-round super thin mirror technology with large aperture and high accuracy by loop polishing machine has been firstly mastered in China; and 2) testing system which adopt active supporting technology has been firstly set up for plane mirror with large aperture and high accuracy. The successful work prepared the key ground for the construction of LAMOST project. Meanwhile, it is a significant occurrence for the research and development of giant telescope in the future as well as the optical engineering in China.