A Dirac half-metal material, which has a gapped band structure in one spin channel but Dirac cones in the other, combines two intriguing properties of 100% spin polarization and massless Dirac fermions and has recently started to attract increasing attention. In this work, using first-principles calculations we predict that the disodium carbide (Na2C) monolayer is an intrinsic 2p Dirac half-metal material with 12 fully spin-polarized and symmetry-protected Dirac cones, and a slightly gapped (53 meV) spin-polarized nodal line coexisting in one spin channel, leaving the other spin channel insulated with a gap of 1.9 eV.
View Article and Find Full Text PDFTwo-dimensional (2D) group-III-V honeycomb films have attracted significant interest for their potential application in fields of quantum computing and nanoelectronics. Searching for 2D III-V films with high structural stability and large-gap are crucial for the realizations of dissipationless transport edge states using quantum spin Hall (QSH) effect. Based on first-principles calculations, we predict that the methyl-functionalized InBi monolayer (InBiCH3) has no dynamic instability, and hosts QSH state with a band gap as large as 0.
View Article and Find Full Text PDFQuantum spin Hall (QSH) effect of two-dimensional (2D) materials features edge states that are topologically protected from backscattering by time-reversal symmetry. However, the major obstacles to the application for QSH effect are the lack of suitable QSH insulators with a large bulk gap. Here, we predict a novel class of 2D QSH insulators in X-decorated plumbene monolayers (PbX; X = H, F, Cl, Br, I) with extraordinarily giant bulk gaps from 1.
View Article and Find Full Text PDFAn epidemic of rash and fever illnesses suspected of hand, foot and mouth disease (HFMD) occurred in Gansu Province of China in 2008, laboratory tests were performed in order to identify the pathogen that caused this epidemic. Eight clinical specimens collected from the 4 patients (each patient has throat swab and herpes fluid specimens) with rash and febrile illness, were inoculated onto RD and HEp-2 cells for virus isolation, and the viral nucleic acid was then extracted with the positive virus isolates, the dual-channel real-time reverse transcript-polymerase chain reaction (RT-PCR) was performed to detect the nucleic acid of human enterovirus (HEV) in the viral isolates at the same time. For the viral isolates with the negative results of HEV, a sequence independent single primer amplification technique (SISPA) was used for "unknown pathogen" identification.
View Article and Find Full Text PDFGuang Pu Xue Yu Guang Pu Fen Xi
April 2010
Crystal can be crystallographically oriented by molecular spectrum with the change in band shift, band intensity, and band shape. The three groups of band shift of augite are different between vertical to c-axis and parallel to c-axis: the first peak value 3 629-3 633 red shifts to 3 601-3 616; the same as the second peak value 3 514-3 543; on the contrary, the third peak value 3 460-3 465 is blue shift. The intensity of the first band is equivalent in two directions, while the second and the third parallel to c-axis are much stronger than the vertical.
View Article and Find Full Text PDFBy testing the Raman spectra of megacryst pyroxene, enstatite and diopside in terms of location, shape and intensity, the symmetries of the main spectral band of pyroxene and the vibration modes of Raman shift were identified. The spectral bands of corresponding ionic groups such as non-bridge oxygen Si-O- and bridge oxygen Si-O0, O-Si-O and M-O were assigned for vibrational mode. Through the change in the intensity of the spectral band in different section direction and the deficiency of some spectral bands, the orientation problem in mineral crystallography was preliminarily studied.
View Article and Find Full Text PDFGuang Pu Xue Yu Guang Pu Fen Xi
April 2003
Monazite glass-ceramics consist of both monazite and metaphoshate glass phases. The absorption bands of both phases do not overlap each other, and the absorption intensities of bands 1,275 and 616 cm-1 vary with the glass contents. The correlation coefficient between logarithmic absorbance ratio of the two bands and glass contents was r = 0.
View Article and Find Full Text PDF