Loose graphene sheets, one to a few atomic layers thick, are often observed on freshly cleaved HOPG surfaces. A straightforward technique using electrostatic attraction is demonstrated to transfer these graphene sheets to a selected substrate. Sheets from one to 22 layers thick have been transferred by this method. One sheet after initial deposition is measured by atomic force microscopy to be only an atomic layer thick (∼0.35 nm). A few weeks later, this height is seen to increase to ∼0.8 nm. Raman spectroscopy of a single layer sheet shows the emergence of an intense D band which dramatically decreases as the number of layers in the sheet increase. The intense D band in monolayer graphene is attributed to the graphene conforming to the roughness of the substrate. The disruption of the C-C bonds within the single graphene layer could also contribute to this intense D band as evidenced by the emergence of a new band at 1620 cm(-1).
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http://dx.doi.org/10.1088/0957-4484/18/13/135301 | DOI Listing |
J Phys Chem B
January 2025
Department of Computational Sciences, School of Basic Sciences, Central University of Punjab, Bathinda 151401, India.
The effect of confinement on the tetrahedral ordering of liquid water plays a vital role in controlling their microscopic structure and dynamics as well as their spectroscopic properties. In this article, we have performed the classical molecular dynamics simulations of four different CTAB/water/chloroform reverse micelles with varied water content to study how the tetrahedral ordering of nanoscale water inside reverse micellar confinement influences the microscopic dynamics and the structural relaxation of water···water hydrogen bonds and its impact on the low-frequency intermolecular vibrational bands. We have noticed from the results obtained from simulated trajectories the lowering trends of tetrahedral ordering of water pools in reverse micellar confinements as we move from bulk to confined and strictly confined environments.
View Article and Find Full Text PDFPain Rep
February 2025
Department of Occupational Therapy, Graduate School of Rehabilitation Science, Osaka Metropolitan University, Osaka, Japan.
Introduction: Chronic low back pain (CLBP) is a global health issue, and its nonspecific causes make treatment challenging. Understanding the neural mechanisms of CLBP should contribute to developing effective therapies.
Objectives: To compare current source density (CSD) and functional connectivity (FC) extracted from resting electroencephalography (EEG) between patients with CLBP and healthy controls and to examine the correlations between EEG indices and symptoms.
Complete 2π cycling of a phase around a phase singularity leads to a rapid phase variation in the nearby zones and forms a sharp local -vector peak. In this paper, the intensity distribution in the spatial domain is transformed into a -vector distribution in the wave vector domain, and we prove that the local -vector peak is generated at the point of minimum light field intensity. The local -vector peak is sharper when the minimum point is closer to the phase singularity.
View Article and Find Full Text PDFSci Rep
January 2025
School of Electronic Science and Engineering, Xiamen University, Xiamen, 361005, China.
Metasurfaces have exhibited excellent capabilities in controlling main characteristics of electromagnetic fields. Thus, a lot of significant achievements have been attained in many areas especially in the fields of hologram and near-field imaging. However, some of these designs are implemented in a manner of interleaved subarrays that complicates the design and makes them difficult to achieve integration.
View Article and Find Full Text PDFClin Imaging
January 2025
Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN 55905, United States of America.
Purpose: To evaluate henna as a durable skin marker on various skin tones for sonographic targeting and to identify the shortest duration of henna application needed for practical clinical workflow.
Materials And Methods: Prospective study applying seven henna lines through ultrasound (US) gel on the forearms of 15 healthy participants equally represented across the validated six-color bar tool. Color bar categories 1-2, 3-4, and 5-6 were designated low, moderate, and high-melanin groups, respectively.
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