High-density amorphous phase of silicon carbide obtained under large plastic shear and high pressure

In situ x-ray diffraction study of the hexagonal 6H SiC under pressure and shear in rotational diamond anvil cell is performed that reveals phase transformation to the new high-density amorphous (hda) phase SiC. In contrast to known low-density amorphous SiC, hda-SiC is promoted by pressure and unstable under pressure release. The critical combination of pressure ∼30 GPa and rotation of an anvil of 2160° that causes disordering is determined

Phase transition and structure of silver azide at high pressure

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98719/1/JApplPhys_110_023524.pd

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Influence of match congestion on performances in the National Basketball Association

The ability to recover from official match-play across a single and multiple matches is often considered a key factor in subsequent performance for modern professional basketball. The aims of this study were to: (i) explore the differences in match performances between different match congestion cycles (i.e., matches separated by zero, one, or two or greater days of rest); and (ii) identify the key performance indicators (KPIs) discriminating between winning and losing during different match congestion cycles. The current study indicated that scoring close to (i.e., within the paint) (ES = 0.08) or very far away (i.e., Three-point, ES = 0.05) was significantly greater for winning matches separated by 1- and 2-days of rest compared to consecutive matches (i.e., 0 rest days between matches). Additionally, shooting efficiency (P < 0.001), and attaining Defensive Rebounds (P < 0.001) and Steals (P < 0.001), were significant offensive and defensive KPIs that differentiated winning and losing teams. Similarly, opponent quality and match pace were important situational variables that affected match outcome during different match congestion cycles. While match location had an impact on winning following 1- and 2-days of rest, it had no impact for back-to-back matches (i.e., 0 days between matches). The current results will support coaches' offensive, defensive and recovery strategies during various match congestion cycles for a greater probability of winning NBA matches

High-density amorphous phase of silicon carbide obtained under large plastic shear and high pressure

In situ x-ray diffraction study of the hexagonal 6H SiC under pressure and shear in rotational diamond anvil cell is performed that reveals phase transformation to the new high-density amorphous (hda) phase SiC. In contrast to known low-density amorphous SiC, hda-SiC is promoted by pressure and unstable under pressure release. The critical combination of pressure ∼30 GPa and rotation of an anvil of 2160° that causes disordering is determined.This article is from Physical Review B 85 (2012): 054114, doi:10.1103/PhysRevB.85.054114. Posted with permission.</p

Phase transition and structure of silver azide at high pressure

ilver azide (AgN 3) was compressed up to 51.3 GPa. The results reveal a reversible second-order orthorhombic-to-tetragonal phase transformation starting from ambient pressure and completing at 2.7 GPa. The phase transition is accompanied by a proximity of cell parameters aand b, a 3° rotation of azide anions, and a change of coordination number from 4-4 (four short, four long) to eight fold. The crystal structure of the high pressure phase is determined to be inI4/mcm space group, with Ag at 4a, N1 at 4d, and N2 at 8h Wyckoff positions. Both of the two phases have anisotropic compressibility: the orthorhombic phase exhibits an anomalous expansion under compression along a-axis and is more compressive along b-axis than c-axis; the tetragonal phase is more compressive along the interlayer direction than the intralayer directions. The bulk moduli of the orthorhombic and tetragonal phases are determined to be KOT = 39 ± 5 GPa with KOT’ = 10 ± 7 and KOT = 57 ± 2 GPa with KOT’ = 6.6 ± 0.2, respectively.The following article appeared in Journal of Applied Physics 110 (2011): 023524 and may be found at http://dx.doi.org/10.1063/1.3610501.</p

Tunable Planar Focusing Based on Hyperbolic Phonon Polaritons in alpha-MoO3

| openaire: EC/H2020/820423/EU//S2QUIP | openaire: EC/H2020/965124/EU//FEMTOCHIP | openaire: EC/H2020/872049/EU//IPN-Bio | openaire: EC/H2020/834742/EU//834742 Funding Information: The authors acknowledge Dr. Pablo Alonso‐González, Dr. Javier Martín‐Sánchez, and Dr. Jiahua Duan (Departamento de Física, Universidad de Oviedo) for valuable discussions and constructive comments, and acknowledge Nanofab Lab @ NCNST for helping with sample fabrication. This work was supported by the National Key Research and Development Program of China (Grant No. 2020YFB2205701), the National Natural Science Foundation of China (Grant Nos. 51902065, 52172139, 51925203, U2032206, 52072083, and 51972072), Beijing Municipal Natural Science Foundation (Grant No. 2202062), and Strategic Priority Research Program of Chinese Academy of Sciences (Grant Nos. XDB36000000 and XDB30000000). F.J.G.A. acknowledges the ERC (Advanced Grant 789104‐eNANO), the Spanish MICINN (PID2020‐112625GB‐I00 and SEV2015‐0522), and the CAS President's International Fellowship Initiative (PIFI) for 2021. Z.P.S. acknowledges the Academy of Finland (Grant Nos. 314810, 333982, 336144 and 336818), The Business Finland (ALDEL), the Academy of Finland Flagship Programme (320167,PREIN), the European Union's Horizon 2020 research and innovation program (820423,S2QUIP; 965124, FEMTOCHIP), the EU H2020‐MSCA‐RISE‐872049 (IPN‐Bio), and the ERC (834742). Publisher Copyright: © 2022 Wiley-VCH GmbH.Manipulation of the propagation and energy-transport characteristics of sub-wavelength infrared (IR) light fields is critical for the application of nanophotonic devices in photocatalysis, biosensing, and thermal management. In this context, metamaterials are useful composite materials, although traditional metal-based structures are constrained by their weak mid-IR response, while their associated capabilities for optical propagation and focusing are limited by the size of attainable artificial optical structures and the poor performance of the available active means of control. Herein, a tunable planar focusing device operating in the mid-IR region is reported by exploiting highly oriented in-plane hyperbolic phonon polaritons in alpha-MoO3. Specifically, an unprecedented change of effective focal length of polariton waves from 0.7 to 7.4 mu m is demonstrated by the following three different means of control: the dimension of the device, the employed light frequency, and engineering of phonon-plasmon hybridization. The high confinement characteristics of phonon polaritons in alpha-MoO3 permit the focal length and focal spot size to be reduced to 1/15 and 1/33 of the incident wavelength, respectively. In particular, the anisotropic phonon polaritons supported in alpha-MoO3 are combined with tunable surface-plasmon polaritons in graphene to realize in situ and dynamical control of the focusing performance, thus paving the way for phonon-polariton-based planar nanophotonic applications.Peer reviewe