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
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.
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
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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