535 research outputs found
Quantum Phase transition under pressure in a heavily hydrogen-doped iron-based superconductor LaFeAsO
Hydrogen (H)-doped LaFeAsO is a prototypical iron-based superconductor.
However, its phase diagram extends beyond the standard framework, where a
superconducting (SC) phase follows an antiferromagnetic (AF) phase upon carrier
doping; instead, the SC phase is sandwiched between two AF phases appearing in
lightly and heavily H-doped regimes. We performed nuclear magnetic resonance
(NMR) measurements under pressure, focusing on the second AF phase in the
heavily H-doped regime. The second AF phase is strongly suppressed when a
pressure of 3.0 GPa is applied, and apparently shifts to a highly H-doped
regime, thereby a "bare" quantum critical point (QCP) emerges. A quantum
critical regime emerges in a paramagnetic state near the QCP, however, the
influence of the AF critical fluctuations to the SC phase is limited in the
narrow doping regime near the QCP. The optimal SC condition ( 48 K)
is unaffected by AF fluctuations
Relationship Between Excitability of Spinal Motor Neurons in Remote Muscles and Voluntary Movements
In physical therapy, it is important to understand the influence of the contraction of a particular muscle on other muscles. The mechanism of the facilitation effect of muscle contraction in healthy subjects has been analyzed in previous studies. These studies indicated that muscle contraction with voluntary movement enhances the excitability of spinal motor neurons and motor areas in the cerebral cortex that are not directly associated with the contracting muscle. Furthermore, it has been reported that the facilitation effects on remote muscles not related to movement are affected by the elapsed time since the start of the movement, the strength of muscle contraction, the number of muscle spindles, and the difficulty of the movement. In addition, the facilitation effects of difficult voluntary movements of the unilateral upper limbs on spinal motor neurons in the contralateral upper limb decrease with motor learning. We expect that these findings will be useful not only for physical therapy evaluation but also for patient treatment
Influence of Auditory Pacing on the Control of Rhythmic Movement in Physical Therapy
The electromyographic reaction time data responses to various rhythm shifts are discussed in Section 2 of this chapter. The following four experimental designs were introduced: (1) subliminal rhythm shift with shortened interval, (2) subliminal rhythm shift with lengthened interval, (3) subliminal rhythm shift with random interval, and (4) differences in the rate of rhythm shift. We found that the periodic rhythmic stimulation is predicted to comprise some time duration. Furthermore, the reactive movements can be performed without delay under conditions with an interstimulus‐onset interval shift of 7% of 1500 ms. When the physical therapist facilitates rhythmical reactive periodic movement using an external event such as a handclap, it will be desirable to keep the rhythm shift within 7% of the interstimulus‐onset interval. The variabilities of the intertap interval in the continuation paradigm of sensorimotor synchronization are discussed in Section 3. The participants performed self‐paced, synchronization‐continuation, and syncopation‐continuation tapping tasks. We found that the accuracy of the periodic movement with an interstimulus‐onset interval of 1000 ms can be improved by using auditory pacing. However, the consistency of periodic movement is mainly dependent on innate skill; thus, improvement in consistency from pacing alone is unlikely
Thermodynamic Reverse Bounds for General Open Quantum Processes
Various quantum thermodynamic bounds are shown to stem from a single tighter
and more general inequality, consequence of the operator concavity of the
logarithmic function. Such an inequality, which we call the "thermodynamic
reverse bound", is compactly expressed as a quantum relative entropy, from
which it inherits mathematical properties and meaning. As concrete examples, we
apply our bound to evaluate the thermodynamic length for open processes, the
heat exchange in erasure processes, and the maximal energy outflow in general
quantum evolutions.Comment: v2: added six colorful plots for the heat exchanged in erasure
processes, accepted in PRA; v1: 6 pages, two-colum
Pressure-induced quantum critical point in a heavily hydrogen-doped iron-based superconductor LaFeAsO
An iron-based superconductor LaFeAsOH (0 0.6)
undergoes two antiferromagnetic (AF) phases upon H doping. We investigated the
second AF phase (=0.6) using NMR techniques under pressure. At pressures up
to 2 GPa, the ground state is a spin-density-wave state with a large gap;
however, the gap closes at 4.0 GPa, suggesting a pressure-induced quantum
critical point. Interestingly, the gapped excitation coexists with gapless
magnetic fluctuations at pressures between 2 and 4 GPa. This coexistence is
attributable to the lift up of the orbital to the Fermi level, a
Lifshitz transition under pressure
An obstacle extraction method using virtual disparity image
金沢大学理工研究域機械工学系The driving support system is one of most important research field in intelligent transport system (ITS). In this paper, we address an obstacle extraction method for driving support system. The stereovision system is one of most suit sensor to recognize details of environment. On the other hand, a disparity image obtained by stereovision system has quite a lot of information. Therefore an efficient algorithm to analyze obtained disparity image is strongly demanded. If the road surface is extracted, obstacles can be easily extracted by evaluating whether one object touch on a road or not. In this paper, we propose a novel method to estimate three-dimensional road surface position by using virtual disparity image. Moreover, an obstacle extraction method is expressed. ©2007 IEEE
Identification of the Tandem Running Pheromone in Diacamma sp. from Japan (Hymenoptera, Formicidae)
The Japanese queenless ponerine ant Diacamma sp. from Japan employs tandem running during nest relocation, in which a leader ant guides nestmate followers one at a time. We replicated this process by presenting one entire abdominal part of a leader, except for the petiole to followers. When the abdominal part had been rinsed with n-hexane, however, it attracted significantlyfewer followers. This suggests that chemicals on the leader’s abdominal part evoke tandem running. Dissection of abdominal major exocrine glands revealed that the Dufour’s gland was the source of this chemical signal. The chemicals were eluted in the hydrocarbon fraction by silica-gel column chromatography, and the quantitatively major component was estimated as heptadecene (C17:1) through gas chromatograph-mass spectrometer (GCMS) analysis. The position of the double bond was estimated to be between the 8th and 9th carbons through analysis of the epoxidized compound. Only (Z)-isomers of 8-heptadecene evoked tandem running in the followers. We identified the tandem running pheromone of this ant species to be (Z)-8- heptadecene. (163
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