544 research outputs found
Rotating Kaluza-Klein Multi-Black Holes with Godel Parameter
We obtain new five-dimensional supersymmetric rotating multi-Kaluza-Klein
black hole solutions with the Godel parameter in the Einstein-Maxwell system
with a Chern-Simons term. These solutions have no closed timelike curve outside
the black hole horizons. At the infinity, the space-time is effectively
four-dimensional. Each horizon admits various lens space topologies
L(n;1)=S^3/Z_n in addition to a round S^3. The space-time can have outer
ergoregions disjointed from the black hole horizons, as well as inner
ergoregions attached to each horizon. We discuss the rich structures of
ergoregions.Comment: 19 pages, 4 figure
Squashed Kerr-Godel Black Holes - Kaluza-Klein Black Holes with Rotations of Black Hole and Universe -
Applying squashing transformation to Kerr-Godel black hole solutions, we
present a new type of a rotating Kaluza-Klein black hole solution to the
five-dimensional Einstein-Maxwell theory with a Chern-Simon term. The new
solutions generated via the squashing transformation have no closed timelike
curve everywhere outside the black hole horizons. At the infinity, the metric
asymptotically approaches a twisted S^1 bundle over a four-dimensional
Minkowski space-time. One of the remarkable features is that the solution has
two independent rotation parameters along an extra dimension associated with
the black hole's rotation and the Godel's rotation. The space-time also admits
the existence of two disconnected ergoregions, an inner ergoregion and an outer
ergoregion. These two ergoregions can rotate in the opposite direction as well
as in the same direction.Comment: 24 pages, 16 figure
Collision-sensitive neurons in the optic tectum of the bullfrog, Rana catesbeiana
In this study, we examined the neuronal correlates of frog collision avoidance behavior. Single unit recordings in the optic tectum showed that 11 neurons gave selective responses to objects approaching on a direct collision course. The collision-sensitive neurons exhibited extremely tight tuning for collision bound trajectories with mean half-width at half height values of 0.8 and 0.9° (n = 4) for horizontal and vertical deviations, respectively. The response of frog collision-sensitive neurons can be fitted by a function that simply multiplies the size dependence of its response, e(-αθ(t)), by the image\u27s instantaneous angular velocity θ\u27(t). Using fitting analysis, we showed that the peak firing rate always occurred after the approaching object had reached a constant visual angle of 24.2 ± 2.6° (mean ± SD; n = 8), regardless of the approaching velocity. Moreover, a linear relationship was demonstrated between parameters l/v (l: object\u27s half-size, v: approach velocity) and time-to-collision (time difference between peak neuronal activity and the predicted collision) in the 11 collision-sensitive neurons. In addition, linear regression analysis was used to show that peak firing rate always occurred after the object had reached a constant angular size of 21.1° on the retina. The angular thresholds revealed by both theoretical analyses were comparable and showed a good agreement with that revealed by our previous behavioral experiments. This strongly suggests that the collision-sensitive neurons of the frog comprise a threshold detector, which triggers collision avoidance behavior
Solar thermophotovoltaic using Al2O3/Er3 Al5O12 eutectic composite selective emitter
科研費報告書収録論文(課題番号:11555057・基盤研究(B)(2)・H11~H13/研究代表者:湯上, 浩雄/太陽熱光起電力による高温輻射-電力直接変換システムの開発
Charged Rotating Kaluza-Klein Black Holes in Five Dimensions
We construct a new charged rotating Kaluza-Klein black hole solution in the
five-dimensional Einstein-Maxwell theory with a Chern-Simon term. The features
of the solutions are also investigated. The spacetime is asymptotically locally
flat, i.e., it asymptotes to a twisted bundle over the
four-dimensional Minkowski spacetime. The solution describe a non-BPS black
hole rotating in the direction of the extra dimension. The solutions have the
limits to the supersymmetric black hole solutions, a new extreme non-BPS black
hole solutions and a new rotating non-BPS black hole solution with a constant
twisted fiber.Comment: 18 pages, 4 figure
Generation of wavelength-tunable few-cycle pulses in the mid-infrared at repetition rates up to 10 kHz
We demonstrate a compact and tunable mid-infrared light source that provides carrier-envelope-phase (CEP)-locked pulses at repetition rates from 500 Hz to 10 kHz. The seed pulses were generated by intra-pulse difference frequency mixing of the output of an Yb:KGW regenerative amplifier that had been spectrally broadened by continuum generation using multiple plates. Then, a two-stage optical parametric amplifier was used to obtain output energies of about 100 µJ/pulse for center wavelengths between 2.8 and 3.5 µm. Owing to the intense pulse energies, it was possible to compress the multi-cycle pulses down to two-cycle pulses using YAG and Si plates
Newly Designed Specula for Laryngomicroscopy
We produced specula for laryngomicroscopy to observe blind spots in the operating field. Use of these specula has facilitated detailed observation of the lower surface of the false vocal folds, laryngeal ventricle, and subglottis, which were previously in blind spots. The specula are useful in the following ways:
1) clarifying blind spots for improved diagnosis and providing more accurate surgical margins; 2) observing the lower lips of the vocal folds in phonosurgery; and 3) Vaporizing with laser reflection. The specula are cheap and easy to use and are well worth considering for application to laryngomicroscopy
Association Between SLFN11 and Antitumor Activity of Trabectedin
Background/Aim: Trabectedin is a DNA-damaging agent and has been approved for the treatment of patients with advanced soft tissue sarcoma. Schlafen 11 (SLFN11) was identified as a dominant determinant of the response to DNA-damaging agents. The aim of the study was to clarify the association between SLFN11 expression and the antitumor activity of trabectedin. Materials and Methods: The antitumor activity of trabectedin was evaluated under different expression levels of SLFN11 regulated by RNA interference and CRISPR-Cas9 systems, and the combined antitumor activity of ataxia telangiectasia and Rad3-related protein kinase (ATR) inhibitor and trabectedin in sarcoma cell lines using in vitro a cell viability assay and in vivo xenograft models. Results: SLFN11-knockdown cell lines had a lower sensitivity to trabectedin, compared to parental cells. ATR inhibitor enhanced the antitumor activity of trabectedin in SLFN11-knockdown cells and in a SLFN11-knockout xenograft model. Conclusion: SLFN11 expression might be a key factor in the antitumor activity of trabectedin
Interference effects in high-order harmonics from colloidal perovskite nanocrystals excited by an elliptically polarized laser
Halide perovskite nanocrystals are suitable materials for photonic devices because their highly efficient luminescence can be tuned over a wide wavelength range by changing the nanocrystal composition and size. Here, we report on the high-order harmonic generation in a solution-processed perovskite CsPbBr₃ nanocrystal film that is excited by a strong midinfrared laser. We observe harmonics up to the 13th order, which is ultraviolet light well above the band-gap energy. By using elliptically polarized laser light, we analyze the influence of the sample structure on the intensity of the 5th harmonic. It is also found that the randomness in the orientation of the nanocrystals in the film induces a reduction in the harmonic intensities due to the interference among the harmonics emitted from nanocrystals with different phases. Our observation of high-order harmonics from nanocrystal films opens a way towards the development of an intensity modulator that can be tuned simply by changing the excitation ellipticity
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