2,379 research outputs found
Ground state and edge excitations of quantum Hall liquid at filling factor 2/3
We present a numerical study of fractional quantum Hall liquid at Landau
level filling factor in a microscopic model including long-range
Coulomb interaction and edge confining potential, based on the disc geometry.
We find the ground state is accurately described by the particle-hole conjugate
of a Laughlin state. We also find there are two counter-propagating
edge modes, and the velocity of the forward-propagating mode is larger than the
backward-propagating mode. The velocities have opposite responses to the change
of the background confinement potential. On the other hand changing the
two-body Coulomb potential has qualitatively the same effect on the velocities;
for example we find increasing layer thickness (which softens of the Coulomb
interaction) reduces both the forward mode and the backward mode velocities.Comment: 12 pages, 13 figure
Methods and systems for optically characterizing a turbid material using a structured incident beam
Special character modification may be required in the abstract.Methods and systems for optically characterizing a turbid sample are provided. A structured light beam is impinged on the sample. The sample includes an embedded region. A reflected light image of the structured light beam is detected from the sample. A measured reflectance image of the structured light beam for the sample is determined based on the reflected light image and a reflectance standard. The following parameters are determined: absorption coefficients ÿa, scattering coefficient ÿs and anisotropy factor g of the sample from the reflectance image. A size parameter of the embedded region is estimated based on the absorption coefficients ÿa, scattering coefficient ÿs and/or anisotropy factor g of the sample from the measured reflectance image
Comparative Study of TCM Syndrome Scale for Liver Disease and Chronic Liver Disease Questionnaire Based on Assessment of Posthepatitic Cirrhosis
Objective. To compare and analyze the relevance and applied value of chronic liver disease questionnaire (CLDQ) and Traditional Chinese Medicine liver disease questionnaire (TCMLDQ) in patients with posthepatitic cirrhosis. Methods. The data of 146 patients' scales of CLDQ and TCMLDQ which based on the characteristics of chinese medical symptoms were collected. We made comparative analysis of the relationship between these two scales by the linear regression model and canonical correlation method and evaluated the advantages and disadvantages of two scales about its items setting and dimension definition. Result. There is a negative correlation in total scores between the two scales and the linear regression equation: CLDQ = 239.38 − 1.232TCMLDQ. The further canonical correlation analysis was used to analyze the two extracted canonical correlative variables with significances (P < 0.05), and the results showed that the overall negative correlation between the two scales mainly came from contributions of both the four dimensions of TCMLDQ (CS, GSYX, GYPX, and OS) and the five dimensions of CLDQ (AS, FA, SS, AC, and EF). Conclusion. These two scales have good consistency in the evaluation of severity and life quality of liver cirrhosis patients, so we suggested that TCMLDQ can be used to evaluate the severity and life quality of patients with posthepatitic cirrhosis
Enhanced mechanical, thermal and flame retardant properties by combining graphene nanosheets and metal hydroxide nanorods for Acrylonitrile–Butadiene–Styrene copolymer composite
Three metal hydroxide nanorods (MHR) with uniform diameters were synthesized, and then combined with graphene nanosheets (GNS) to prepare acrylonitrile–butadiene–styrene (ABS) copolymer composites. An excellent dispersion of exfoliated two-dimensional (2-D) GNS and 1-D MHR in the ABS matrix was achieved. The effects of combined GNS and MHR on the mechanical, thermal and flame retardant properties of the ABS composites were investigated. With the addition of 2 wt% GNS and 4 wt% Co(OH)2, the tensile strength, bending strength and storage modulus of the ABS composites were increased by 45.1%, 40.5% and 42.3% respectively. The ABS/GNS/Co(OH)2 ternary composite shows the lowest maximum weight loss rate and highest residue yield. Noticeable reduction in the flammability was achieved with the addition of GNS and Co(OH)2, due to the formation of more continuous and compact charred layers that retarded the mass and heat transfer between the flame and the polymer matrix
Photoplethysmographic imaging and analysis of pulsatile pressure wave in palmar artery at 10 wavelengths
CC BY: © The Authors. Published by SPIE under a Creative Commons Attribution 4.0 International License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.Significance
As a noncontact method, imaging photoplethysmography (iPPG) may provide a powerful tool to measure pulsatile pressure wave (PPW) in superficial arteries and extract biomarkers for monitoring of artery wall stiffness.
Aim
We intend to develop a approach for extraction of the very weak cardiac component from iPPG data by identifying locations of strong PPW signals with optimized illumination wavelength and determining pulse wave velocity (PWV).
Approach
Monochromatic in vivo iPPG datasets have been acquired from left hands to investigate various algorithms for retrieval of PPW signals, distribution maps and waveforms, and their dependence on arterial location and wavelength.
Results
A robust algorithm of pixelated independent component analysis (pICA) has been developed and combined with spatiotemporal filtering to retrieve PPW signals. Spatial distributions of PPW signals have been mapped in 10 wavelength bands from 445 to 940 nm and waveforms were analyzed at multiple locations near the palmar artery tree. At the wavelength of 850 nm selected for timing analysis, we determined PWV values from 12 healthy volunteers in a range of 0.5 to 5.8 m/s across the hand region from wrist to midpalm and fingertip.ECU Open Access Publishing Support Fun
Quantitative assessment of image motion blur in diffraction images of moving biological cells
Motion blur (MB) presents a significant challenge for obtaining high-contrast image data from biological cells with a polarization diffraction imaging flow cytometry (p-DIFC) method. A new p-DIFC experimental system has been developed to evaluate the MB and its effect on image analysis using a time-delay-integration (TDI) CCD camera. Diffraction images of MCF-7 and K562 cells have been acquired with different speed-mismatch ratios and compared to characterize MB quantitatively. Frequency analysis of the diffraction images shows that the degree of MB can be quantified by bandwidth variations of the diffraction images along the motion direction. The analytical results were confirmed by the p-DIFC image data acquired at different speed-mismatch ratios and used to validate a method of numerical simulation of MB on blur-free diffraction images, which provides a useful tool to examine the blurring effect on diffraction images acquired from the same cell. These results provide insights on the dependence of diffraction image on MB and allow significant improvement on rapid biological cell assay with the p-DIFC method
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