June, 2004

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Basic Research

Scientists at Institute of Physics Predicted the Existence of a New Two-dimensional Ice Structure

Recently, scientists from Prof. E.G. Wang's research group at Institute of Physics, CAS has made a great breakthrough in the study of water adsorption on a silica surface. They predicted the existence of a new two-dimensional (2D) ice structure for the first time.

Based on a series of research works on water adsorption on surfaces in recent years, they studied the adsorption of water on a fully hydroxylated silica surface by using density-functional total-energy and molecular dynamics calculations. The surface of silica covered by geminal hydroxyls has been taken as the substrate. A well-ordered and stable two-dimensional ice with quadrangular and octagonal patterns of hydrogen bond networks-named as tessellation ice-is found on the surface. With the vibrational recognition, the four water molecules in a quadrangle are found bonded by strong H bonds, while the quadrangles are connected to each other by weak H bonds. The formation of the new ice phase is mainly determined by the requirement of saturating hydrogen bonds among both water molecules and surface hydroxyls. More interestingly, the study shows that the tessellation ice is stable even at the room temperature (300 K). This new well-defined 2D ice structure is neither seen in the bulk nor on other surface before. The result was published in Phys. Rev. Lett. 92, 146102 (2004) by Jianjun Yang, Sheng Meng, L.F. Xu and E.G. Wang.

Research of Meteorite from Mars by PMO

Recently, a study conducted by Professor Xu, Weibiao of Purple Mountain Observatory (PMO) CAS and the collaborators of Nanjing University in China and Arizona University in USA, on a iherzolitic shergottite (GRV99027), which was firstly picked out by Chinese explorers in Antarctica, revealed almost identical mineralogy, petrography, rare-earth element geochemistry (REE), and hydrogen isotopic composition to those of the iherzolitic shergottites Allan Hills (ALH) A77005, Lewis Cliff (LEW) 88516, and Yamato (Y-) 793605. The result is published on Meteoritics & Planetary Science 39, Nr 5, 701-709, issued in May, 2004.

Having a weight of 9.7 gram, the meteorite GRV99027 was the first iherzolitic shergottite collected from the ice field of the Grove Mountains, Antarctica, by the 16th Chinese Antarctic Research Expedition in 1999/2000. Being identified to be one of five such iherzolitic shergottites known in the world, it is discovered as a sub-group of olivine, belonging to the wacke iherzolitic shergottite from precise analyses of REE distribution according to the mineral microdistribution and the hydrogen isotope composition by use of the most advanced ion microprobe. Having a age of about 2 hundred million years and being the youngest one among those ever-founded meteorites, this kind of rocks formed by igneous processes from magma chamber in Martian crust, bears a crucial importance in studying Mars' geological evolutionary history.

Advance in the Study of Visible Light Photocatalytic Degradation of Toxic Organic Pollutants

An advance in the study of visible light photocatalytic degradation of toxic organic pollutants was achieved based on the cooperation of the group of Prof. Jincai Zhao in the Key Lab of Photochemistry, and the group of Prof. Zhigang Shuai in the Key Lab of Organic Solids, Institute of Chemistry, CAS. The research results were published on J. Am. Chem. Soc. (2004úČ126úČ4782).

Since TiO2 was found to be an efficient photocatalyst, intense research has concentrated on photocatalytic degradation of toxic organic pollutants by TiO2 photocatalyst. However, this material is only active upon UV excitation because of its large energy band gap of 3.2 eV. The study reported doped TiO2 with both a nonmetal element, boron, and a metal oxide, Ni2O3, by a simple method of modified sol-gel synthesis. The photocatalyst, Ni2O3/TiO2-xBx, thus obtained presents high photocatalytic activity in the visible region, which can efficiently degrade and mineralize toxic organic pollutants such as trichlorophenol (TCP), 2,4-dichlorophenol (2,4-DCP) and sodium benzoate. The study demonstrates that the modification of TiO2 both to extend its spectral response to the visible region and to improve its catalytic efficiency can be achieved by doping with two components: a non-metal (boron) and a metal oxide (nickel oxide).

The Cloned Cow "Fufu" Gave Birth to A Calf By Artifical Insemination

The cloned cow "Fufu", gave birth to a calf by artifical insemination in Cao xian County, Shandong Province, at 4:12am March 31,2004.This calf, named "Xingxing", is 85 centimeters high,80 centimeters long and weighing 39 kilograms. With a chest circumference of 80 centimeters, its body temperature, heart beat and breath rate and other physiological indexes are normal upon birth. "Fufu" is one of the only surviving twins among the first somatic cell cloned cows, which were produced by the Institute of Zoology, Chinese Academy of Sciences and Yinxiang Company.

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