1,238 research outputs found

    The complex refractive indices of the liquid crystal mixture E7 in the terahertzfrequencyrange

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    We have used terahertz time-domain spectroscopy to investigate the complex optical constants and birefrin-gence of a widely used liquid crystal mixture E7 in both nematic and isotropic phases (26°C–70°C).The ex-tinction coefficient of E7 at room temperature is less than 0.035 and without sharp absorption features in the frequency range of 0.2–2.0 THz. The extraordinary (ne)and ordinary (no)indices of refraction at 26°C are 1.690–1.704 and 1.557–1.581, respectively, giving rise to a birefringence of 0.130–0.148 in this frequency range. The temperature-dependent(26°C–70°C)order parameter extracted from the birefringence data agrees with that in the visible region quite well. Further, the temperature gradients of the terahertz optical constants of E7 are also determined. The optical constants of E7 in the terahertz or sub-millimeter wave range are found to deviate significantly from values predicated by the usual extended Cauchy equations used in the visible and near-infrared

    Genetic regulation of mouse liver metabolite levels.

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    We profiled and analyzed 283 metabolites representing eight major classes of molecules including Lipids, Carbohydrates, Amino Acids, Peptides, Xenobiotics, Vitamins and Cofactors, Energy Metabolism, and Nucleotides in mouse liver of 104 inbred and recombinant inbred strains. We find that metabolites exhibit a wide range of variation, as has been previously observed with metabolites in blood serum. Using genome-wide association analysis, we mapped 40% of the quantified metabolites to at least one locus in the genome and for 75% of the loci mapped we identified at least one candidate gene by local expression QTL analysis of the transcripts. Moreover, we validated 2 of 3 of the significant loci examined by adenoviral overexpression of the genes in mice. In our GWAS results, we find that at significant loci the peak markers explained on average between 20 and 40% of variation in the metabolites. Moreover, 39% of loci found to be regulating liver metabolites in mice were also found in human GWAS results for serum metabolites, providing support for similarity in genetic regulation of metabolites between mice and human. We also integrated the metabolomic data with transcriptomic and clinical phenotypic data to evaluate the extent of co-variation across various biological scales

    Holographic fermions in charged Gauss-Bonnet black hole

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    We study the properties of the Green's functions of the fermions in charged Gauss-Bonnet black hole. What we want to do is to investigate how the presence of Gauss-Bonnet coupling constant α\alpha affects the dispersion relation, which is a characteristic of Fermi or non-Fermi liquid, as well as what properties such a system has, for instance, the Particle-hole (a)symmetry. One important result of this research is that we find for q=1q=1, the behavior of this system is different from that of the Landau Fermi liquid and so the system can be candidates for holographic dual of generalized non-Fermi liquids. More importantly, the behavior of this system increasingly similar to that of the Landau Fermi liquid when α\alpha is approaching its lower bound. Also we find that this system possesses the Particle-hole asymmetry when q0q\neq 0, another important characteristic of this system. In addition, we also investigate briefly the cases of the charge dependence.Comment: 22 pages, 6 figures; version published in JHE

    Dipole Coupling Effect of Holographic Fermion in the Background of Charged Gauss-Bonnet AdS Black Hole

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    We investigate the holographic fermions in the charged Gauss-Bonnet AdSdAdS_{d} black hole background with the dipole coupling between fermion and gauge field in the bulk. We show that in addition to the strength of the dipole coupling, the spacetime dimension and the higher curvature correction in the gravity background also influence the onset of the Fermi gap and the gap distance. We find that the higher curvature effect modifies the fermion spectral density and influences the value of the Fermi momentum for the appearance of the Fermi surface. There are richer physics in the boundary fermion system due to the modification in the bulk gravity.Comment: 16 pages, accepted for publication in JHE

    A simulation study on the measurement of D0-D0bar mixing parameter y at BES-III

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    We established a method on measuring the \dzdzb mixing parameter yy for BESIII experiment at the BEPCII e+ee^+e^- collider. In this method, the doubly tagged ψ(3770)D0D0\psi(3770) \to D^0 \overline{D^0} events, with one DD decays to CP-eigenstates and the other DD decays semileptonically, are used to reconstruct the signals. Since this analysis requires good e/πe/\pi separation, a likelihood approach, which combines the dE/dxdE/dx, time of flight and the electromagnetic shower detectors information, is used for particle identification. We estimate the sensitivity of the measurement of yy to be 0.007 based on a 20fb120fb^{-1} fully simulated MC sample.Comment: 6 pages, 7 figure

    Potassium {4-[(3S,6S,9S)-3,6-dibenzyl-9-isopropyl-4,7,10-trioxo-11–oxa-2,5,8-triazadodecyl]phenyl}trifluoroborate

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    [[abstract]]The reported compound 4 was synthesized and fully characterized by 1H NMR, 13C NMR, 11B NMR, 19F NMR, and high resolution mass spectrometry.[[booktype]]電子版[[countrycodes]]CH

    Micropropagation, Establishment Of Cell Suspension Cultures And Evaluation Of Antioxidant Activities Of Gynura Procumbens

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    Aseptic bud explants of Gynura procumbens, obtained from the axillary buds of field grown mature plants, could be established via surface-sterilization with 20 % Clorox® for 20 minutes. The formation of multiple shoots could be induced on MS medium supplemented with 2.0 mg/L BA with an average of 14.7 ± 0.7 shoots produced from each bud explant after four weeks of culture. When the concentration of BA supplemented into the MS medium was reduced to 1.5 mg/L BA, reasonably high number of shoots (13.9 ± 1.3 shoots per explant) can still be produced with less production of abnormal shoots

    Nanostructured Indium Tin Oxides and Other Transparent Conducting Oxides: Characteristics and Applications in the THz Frequency Range

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    Transparent conductors are essential for optoelectronic components operating in the far-infrared or terahertz (THz) frequency range. Indium tin oxide (ITO), extensively used in the visible, is semi-transparent in the far-infrared frequency range. Other types of bulk transparent conducting oxides (TCOs), such as aluminum-doped zinc oxide (AZO) and aluminum and ytterbium-doped zinc oxide (AYZO), have not yet been explored for THz applications. Recently, biomimic nanomaterials have been shown to exhibit exotic optical properties, e.g., broadband, omnidirectional antireflective properties. Indeed, nanostructured ITO was found to exhibit the above desirable characteristics. In this chapter, we describe the fabrication and characterization of several TCOs, including ITO nanomaterials and several types of bulk TCO thin films, e.g., AZO and AYZO. Performance of THz phase shifters with ITO nanomaterials as transparent electrodes and liquid crystals for functionalities is presented

    Liquid-Crystal-Based Phase Gratings and Beam Steerers for Terahertz Waves

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    We review our theoretical and experimental studies on a class of liquid crystal (LC) photonic devices, i.e., terahertz (THz) phase gratings and beam steerers by using LCs. Such gratings can function as a THz polarizer and tunable THz beam splitters. The beam splitting ratio of the zeroth-order diffraction to the first-order diffraction by the grating can be tuned from 10:1 to 3:5. Gratings with two different base dimensions were prepared. The insertion loss is lower by approximately 2.5 dB for the one with the smaller base. The response times of the gratings were also studied and were long (tens of seconds) as expected because of the thick LC layer used. Accordingly, the devices are not suitable for applications that require fast modulation. However, they are suitable for instrumentation or apparatuses that require precise control, e.g., an apparatus requiring a fixed beam splitting ratio with occasional fine tuning. Schemes for speeding up the device responses were proposed. Based on the grating structure, we also achieved an electrically tunable THz beam steerer. Broadband THz radiation can be steered by 8.5° with respect to the incident beam by varying the driving voltages to yield the designed phase gradient

    Quasinormal modes of a regular black hole with sub-Planckian curvature

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    This paper explores the properties of the quasinormal modes (QNMs) of a regular black hole(BH) characterized by a Minkowski core and sub-Planckian curvature. When focusing on a special case, this regular BH exhibits identical large-scale behavior with the Hayward BH and some loop quantum gravity corrected (LQG-corrected) BH. A notable characteristic of the QNMs in this regular BH is the pronounced outburst of overtones when compared to the Schwarzschild BH (SS-BH). This outburst can be attributed to the deviation from the SS-BH in the near-horizon geometry region due to the quantum gravity effect. Furthermore, we compare the QNM properties of the regular BH with those of the Hayward BH and the LQG-corrected BH. A similar phenomenon of overtone outburst is observed in the modes of the overtone. As a conclusion, the QNMs may be a powerful tool for detecting the quantum gravity effect and distinguishing different BH models
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