130 research outputs found
Multilayer graphene shows intrinsic resistance peaks in the carrier density dependence
Since the advent of graphene, a variety of studies have been performed to
elucidate its fundamental physics, or to explore its practical applications.
Gate-tunable resistance is one of the most important properties of graphene and
has been studied in 1-3 layer graphene in a number of efforts to control the
band gap to obtain a large on-off ratio. On the other hand, the transport
property of multilayer graphene with more than three layers is less well
understood. Here we show a new aspect of multilayer graphene. We found that
four-layer graphene shows intrinsic peak structures in the gate voltage
dependence of its resistance at zero magnetic field. Measurement of quantum
oscillations in magnetic field confirmed that the peaks originate from the
specific band structure of graphene and appear at the carrier density for the
bottoms of conduction bands and valence bands. The intrinsic peak structures
should generally be observed in AB-stacked multilayer graphene. The present
results would be significant for understanding the physics of graphene and
making graphene FET devices
The effect of behavioral preferences on skill acquisition in determining unspecified, suitable action patterns to control humanoid robots
This research investigated the effect of behavioral preferences on learning efficiency when attempting to determine unspecified, but suitable action sequences for unfamiliar tasks. The goal of this research was to develop a skill acquisition support system for the elderly to aid them in using unfamiliar IT products, particularly those of welfare systems. Here, behavioral preference is defined as the type of action sequences that people would prefer to adopt for completing unfamiliar tasks. To achieve this goal, this research investigated the action sequences of participants when they attempt to control the posture of an unfamiliar humanoid robot with an unfamiliar controller. The participants were assigned the task of making the humanoid stand on one foot. Machine-learning-based methods were presented for analyzing the behavioral preferences. The analysis results indicate that participants having behavioral preferences of adopting random action sequences can complete the task in a much shorter time, compared to participants having a behavioral preference of adopting action sequences similar to those of previous actions. © 2015 IEEE.37th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBC 2015; MiCo Center, Milano Congressi CenterMilan; Italy; 25 August 2015 through 29 August 2015; Category numberCFP15EMB-ART; Code 11680
Low-energy band structure and even-odd layer number effect in AB-stacked multilayer graphene
How atoms acquire three-dimensional bulk character is one of the fundamental questions in materials science. Before addressing this question, how atomic layers become a bulk crystal might give a hint to the answer. While atomically thin films have been studied in a limited range of materials, a recent discovery showing how to mechanically exfoliate bulk crystals has opened up the field to study the atomic layers of various materials. Here, we show systematic variation in the band structure of high mobility graphene with one to seven layers by measuring the quantum oscillation of magnetoresistance. The Landau fan diagram showed distinct structures that reflected differences in the band structure, as if they were finger prints of multilayer graphene. In particular, an even-odd layer number effect was clearly observed, with the number of bands increasing by one for every two layers and a Dirac cone observed only for an odd number of layers. The electronic structure is significantly influenced by the potential energy arising from carrier screening associated with a gate electric field.This work was supported by MEXT KAKENHI Grant Number JP25107003
Trion confinement in monolayer MoSe2 by carbon nanotube local gating
We have successfully confined trions into a one-dimensional restricted space
of a MoSe2 device with CNT gate electrodes. The dry transfer process, including
deterministic dry transfer of aligned CNTs, has led to an hBN-encapsulated
MoSe2 device with CNT back gate electrodes. In contrast to a location without
CNT gate electrodes, applying voltage via CNT gate electrodes significantly
alters PL spectra at a location with CNT gate electrodes. PL imaging has
revealed that image contrast from trions is linear along the CNT electrode
underneath, consistent with 1D confinement of trions in response to the CNT
local gating. The confinement width obtained from the PL image is 5.5 x 10^2
nm, consistent with nanoscale 1D confined trions with the diffraction limit
broadening. This work has demonstrated electrical control of excitonic states
at the nanoscale, leading to novel optoelectronic properties and exciton
devices in the future
Malignant Peritoneal Mesothelioma Mimicking Ischemic Colitis
The prognosis of malignant peritoneal mesothelioma is extremely poor with a mean survival time of 12 months. The initial symptoms are poor and atypical. Because of its rare entity and little knowledge of its treatments, there are few reports of long-term survival. We encountered a very unique case with strong impression on radiological findings of malignant peritoneal methothelioma. We had misdiagnosed it because of the findings and because the time course was similar to that of ischemic colitis. The radiological findings on CT and enema disappeared within one week after antibiotic therapy
Generation of a transgenic mouse line for conditional expression of human IL-6
IL-6 is a cytokine that is involved in various physiological and pathological conditions, and approaches using gain-of-function transgenic animals have contributed in elucidating IL-6 function. However, studies of the multiple functions of IL-6 in vivo are very time consuming because they require the generation of transgenic mice that harbor the gene encoding IL-6 under the control of specific promoters to mimic different pathologies. Here, we report the establishment of a conditional human IL-6 transgenic mouse, LGL-IL6, which conditionally expresses human IL-6 by taking advantage of the well-characterized Cre recombinase drivers
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