Black phosphorene has attracted much attention as a semiconducting two‐dimensional material. Violet phosphorus is another layered semiconducting phosphorus allotrope with unique electronic and optoelectronic properties. However, no confirmed violet crystals or reliable lattice structure of violet phosphorus had been obtained. Now, violet phosphorus single crystals were produced and the lattice structure has been obtained by single‐crystal x‐ray diffraction to be monoclinic with space group of P2/n (13) (a=9.210, b=9.128, c=21.893 Å, β=97.776°). The lattice structure obtained was confirmed to be reliable and stable. The optical band gap of violet phosphorus is around 1.7 eV, which is slightly larger than the calculated value. The thermal decomposition temperature was 52 °C higher than its black phosphorus counterpart, which was assumed to be the most stable form. Violet phosphorene was easily obtained by both mechanical and solution exfoliation under ambient conditions.

The work function and band alignment of violet phosphorene are demonstrated, giving a practical route for heterojunction structure design.

Charging of insulators modifies local electric field distribution and increases potential threat to the safety of the gas insulated equipment. In this paper, surface charge tailoring techniques are classified and reviewed by introducing a Dam-flood model. Technical solutions of different charge tailoring methods are compared and discussed. The outlook of potential solutions to suppress charge accumulation is recommended and discussed based on industrial consideration.This paper serves as a guide handbook for engineers and researchers into the study of charge tailoring methods.Meanwhile, we hope that the content of this paper could shed some lights upon charge-free insulators to promote the industrial application of HVDC GIL/GIS.

Violet phosphorus, the most stable phosphorus allotrope, has been successfully produced recently. Phonon properties of layered structures are important characteristic features to provide their structural and chemical information. Raman spectroscopy is an easy, nondestructive, and effective characterization path to obtain phonon properties of elemental layered structures. However, no reliable data are available due to the lack of pure violet phosphorus crystals or rational lattice structures. The successful synthesis of violet phosphorus single crystals and further acquisition of its lattice structure give the possibility for the phonon properties of violet phosphorus. The phonon properties of violet phosphorus single crystals have been demonstrated both theoretically and experimentally in this work. The vibrational modes have been assigned. The evolution of Raman features between 103 and 833 K and 0–25 GPa has been studied. The first-order temperature coefficients for Tg, Ptub, and S[P9]–[P9] of violet phosphorus are much larger than those of the reported layered structures. The violet phosphorus has been demonstrated to transfer into A7 black phosphorus (rhombohedral) (>8.5 GPa) and then to a simple cubic one (>13.6 GPa). Only black phosphorus was obtained when the pressure was released back to ambient conditions.

No abstract

Plasma processing with atmospheric pressure plasma jets (APPJs) is attracting attention from both scientific and industrial fields for their capability of flexible plasma release onto targets. It is of great significance to understand the discharge characteristic and underly mechanism of the interfacial phenomenon in plasma surface interaction. In this paper, we investigate the basic surface charging on quartz dielectrics by pulsed He APPJs with double-ring electrodes. The dynamic surface charges are quantitatively acquired with a reflective electro-optic measurement platform on Pockels effect and the fast charge inversion calculation on 2D-FTA. Dynamic distributions of surface charge deposited by the plasma jet are revealed, together with the behavior of ionization waves interacting on the quartz surface. The dependence of surface charge lifetime on pulse width is investigated. Results indicate that after ionization waves reach the surface, a round positive charge cloud is formed on quartz dielectrics with a diameter of 5 ~ 10 mm, charge density of 20 ~ 60 nC/cm2 and total deposition of 40 ~ 160 nC. The plasma jet is capable of transporting more charges onto the quartz surface at a higher rate under higher voltage magnitude. Some interesting phenomena are observed that the lifetime of surface charge relies strongly on pulse widths, almost keeping unchanged during pulse duration. Also, a polarity reversal of surface charging occurs when the pulse width increases to over half-cycle, with a reduced positive charge on pulse-on and a more negative charge deposition on pulse-off. These results provide a non-intrusive tool for an in-depth insight into the basic charging dynamics of plasma surface interaction, which will be of interest to researchers in the plasma community.

No abstract

Osteoporosis is a multifactorial disease in which genetic determinants are modulated by hormonal, environmental and nutritional factors. An important clinical risk factor in the pathogenesis of osteoporosis is the presence of genetics polymorphism in/around susceptibility genes/regions. This study explored whether the region of 4q22.1, which confers risk of developing osteoporosis in some populations, associated with bone mineral density and osteoporosis susceptibility in postmenopausal women of Han Chinese. We investigated 32 SNPs with minor allele frequencies ≥0.05 between 20 kb upstream and 20 kb downstream (40 kb window) of rs6532023, mapping in the 4q22.1 region, which was reported to be significantly associated with osteoporosis in previous studies. We found that rs6532023 was significantly associated with bone mineral density and osteoporosis (corrected p = 0.015) in our sample, including 440 cases and 640 controls, and allele G was supposed as a risk factor while T worked as a protective factor. Further genotype association analyses suggested a similar pattern (corrected p = 0.040). Additionally, analyses by haplotypes indicated that a haplotype block rs7683315-rs6532023-rs1471400-rs1471403 in the region associated with bone mineral density and osteoporosis (global p = 0.032), and risk haplotype A-G-G-C had almost 1.5-fold increased in the cases. To our knowledge, this is the first report to examine 4q22.1 region polymorphisms and osteoporosis in Han Chinese. Our results provide further evidence for an effect of the region of 4q22.1 on the etiology of osteoporosis and suggest that 4q22.1 may be a genetic risk factor for bone mineral density and osteoporosis.