Giant piezoresistivity in a van der Waals material induced by intralayer atomic motions.

The presence of the van der Waals gap in layered materials creates a wealth of intriguing phenomena different to their counterparts in conventional materials. For example, pressurization can generate a large anisotropic lattice shrinkage along the stacking orientation and/or a significant interlayer sliding, and many of the exotic pressure-dependent properties derive from these mechanisms. Here we report a giant piezoresistivity in pressurized β'-InSe.

Natural diamond formation by self-redox of ferromagnesian carbonate.

Formation of natural diamonds requires the reduction of carbon to its bare elemental form, and pressures () greater than 5 GPa to cross the graphite-diamond transition boundary. In a study of shocked ferromagnesian carbonate at the Xiuyan impact crater, we found that the impact pressure-temperature () of 25-45 GPa and 800-900 °C were sufficient to decompose ankerite Ca(Fe,Mg)(CO) to form diamond in the absence of another reductant. The carbonate self-reduced to diamond by concurrent oxidation of Fe to Fe to form a high- polymorph of magnesioferrite, MgFeO Discovery of the subsolidus carbonate self-reduction mechanism indicates that diamonds could be ubiquitously present as a dominant host for carbon in the Earth's lower mantle.

Deformation Behavior across the Zircon-Scheelite Phase Transition.

The pressure effects on plastic deformation and phase transformation mechanisms of materials are of great importance to both Earth science and technological applications. Zircon-type materials are abundant in both nature and the industrial field; however, there is still no in situ study of their deformation behavior. Here, by employing radial x-ray diffraction in a diamond anvil cell, we investigate the dislocation-induced texture evolution of zircon-type gadolinium vanadate (GdVO_{4}) in situ under pressure and across its phase transitions to its high-pressure polymorphs.

[Screening of common deafness gene mutations in 17 000 Chinese newborns from Chengdu based on microarray analysis].

Objective: To achieve early diagnosis for inheritable hearing loss and determine carrier rate of deafness causing gene mutations in order to provide information for premarital, prenatal and postnatal genetic counseling.

Methods: A total of 17 000 dried heel blood spots of normal newborns in Chengdu were collected with informed consent obtained from their parents. Genomic DNA was extracted from dried blood spots using Qiagen DNA extraction kits.

Structural properties of PbVO3 perovskites under hydrostatic pressure conditions up to 10.6 GPa.

High-pressure synchrotron x-ray powder diffraction experiments were performed on PbVO(3) tetragonal perovskite in a diamond anvil cell under hydrostatic pressures of up to 10.6 GPa at room temperature. The compression behavior of the PbVO(3) tetragonal phase is highly anisotropic, with the c-axis being the soft direction.

Large volume collapse observed in the phase transition in cubic PbCrO3 perovskite.

When cubic PbCrO(3) perovskite (Phase I) is squeezed up to approximately 1.6 GPa at room temperature, a previously undetected phase (Phase II) has been observed with a 9.8% volume collapse.

[Raman characterization of rutile phase transitions under high-pressure and high-temperature].

The pressure-induced phase transition of rutile-structured TiO2 was investigated by in-situ Raman spectrum method in a laser-heated diamond anvil cell (DAC). The experiment was conducted at 35 GPa under quasihydrostatic conditions using argon as medium. At room temperature, the rutile-type TiO2 begins to transform to baddeleyite-type phase at 13.