297 research outputs found

    Localized excitons in cubic Zn1-xCdxS lattice matched to GaAs

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    Excitonic properties have been studied in cubic Zn0.42Cd0.58S lattice matched to GaAs. At 2 K, the time-integrated photoluminescence spectrum was composed of single emission peaking at 2.863 eV and its LO-phonon replica. The linewidth of the main peak was 18.5 meV, which fairly well agreed with the theoretical value based on the disorder-induced broadening of exciton luminescence in alloys. In order to assess the emission mechanism, the transient luminescence decay was measured at various emission energies. At the high energy tail (2.883 eV), the luminescence showed exponential decay with a time constant of about 72 ps. On the other hand, the decay time increased with decreasing the detected emission energy. It was about 660 ps at the emission peak (2.863 eV). We interpret these features by means of the model of exciton localization

    PVP2009-77600 ISOLATION PERFORMANCE OF INTELLIGENT SEISMIC ISOLATION SYSTEM USING AIR BEARING

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    ABSTRACT This paper describes three-dimensional isolation performance of seismic isolation system using air bearings

    Catalytic activity of graphene-covered non-noble metals governed by proton penetration in electrochemical hydrogen evolution reaction

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    Hu, K., Ohto, T., Nagata, Y. et al. Catalytic activity of graphene-covered non-noble metals governed by proton penetration in electrochemical hydrogen evolution reaction. Nat Commun 12, 203 (2021). https://doi.org/10.1038/s41467-020-20503-

    Non-volatile hybrid optical phase shifter driven by a ferroelectric transistor

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    Optical phase shifters are essential elements in photonic integrated circuits (PICs) and function as a direct interface to program the PIC. Non-volatile phase shifters, which can retain information without a power supply, are highly desirable for low-power static operations. Here a non-volatile optical phase shifter is demonstrated by driving a III-V/Si hybrid metal-oxide-semiconductor (MOS) phase shifter with a ferroelectric field-effect transistor (FeFET) operating in the source follower mode. Owing to the various polarization states in the FeFET, multistate non-volatile phase shifts up to 1.25{\pi} are obtained with CMOS-compatible operation voltages and low switching energy up to 3.3 nJ. Furthermore, a crossbar array architecture is proposed to simplify the control of non-volatile phase shifters in large-scale PICs and its feasibility is verified by confirming the selective write-in operation of a targeted FeFET with a negligible disturbance to the others. This work paves the way for realizing large-scale non-volatile programmable PICs for emerging computing applications such as deep learning and quantum computing

    Insight into enhanced field-effect mobility of 4H-SiC MOSFET with Ba incorporation studied by Hall effect measurements

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    Improved performance in 4H-SiC metal-oxide-semiconductor field-effect transistors (MOSFETs) by incorporating Ba into insulator/SiC interfaces was investigated by using a combination of the Hall effect and split capacitance-voltage measurements. It was found that a moderate annealing temperature causes negligible metal-enhanced oxidation, which is rather beneficial for increments in field-effect mobility (μFE) of the FETs together with suppressed surface roughness of the gate oxides. The combined method revealed that, while severe μFE degradation in SiC-MOSFETs is caused by a reduction of effective mobile carriers due to carrier trapping at the SiO2/SiC interfaces, Ba incorporation into the interface significantly increases mobile carrier density with greater impact than the widely-used nitrided interfaces

    IL-19 Contributes to the Development of Nonalcoholic Steatohepatitis by Altering Lipid Metabolism

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    Interleukin (IL)-19, a member of the IL-10 family, is an anti-inflammatory cytokine produced primarily by macrophages. Nonalcoholic steatohepatitis (NASH) is a disease that has progressed from nonalcoholic fatty liver disease (NAFLD) and is characterized by inflammation and fibrosis. We evaluated the functions of IL-19 in a NAFLD/NASH mouse model using a 60% high fat diet with 0.1% methionine, without choline, and with 2% cholesterol (CDAHFD). Wild-type (WT) and IL-19 gene-deficient (KO) mice were fed a CDAHFD or standard diet for 9 weeks. Liver injury, inflammation, and fibrosis induced by CDAHFD were significantly worse in IL-19 KO mice than in WT mice. IL-6, TNF-α, and TGF-β were significantly higher in IL-19 KO mice than in WT mice. As a mechanism using an in vitro experiment, palmitate-induced triglyceride and cholesterol contents were decreased by the addition of IL-19 in HepG2 cells. Furthermore, addition of IL-19 decreased the expression of fatty acid synthesis-related enzymes and increased ATP content in HepG2 cells. The action of IL-19 in vitro suppressed lipid metabolism. In conclusion, IL-19 may play an important role in the development of steatosis and fibrosis by directly regulating liver metabolism and may be a potential target for the treatment of liver diseases

    Nonsense mutations at Arg-1947 in two cases of familial neurofibromatosis type 1 in Japanese

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    We report two familial cases of NF1 presenting as C to T transitions changing an Arg-1947 codon to a stop codon. In one of the two families, cosegregation of the mutation with NF1 was demonstrated, indicating this mutation causes the disease in this family. As the same mutation at Arg-1947 has been reported previously in three cases of unrelated Caucasians (two are sporadic; the origin of the other is not reported), the codon at Arg-1947 (CGA) in the NF1 gene is considered to be a hotspot common among different ethnic groups and also among familial and sporadic cases.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47635/1/439_2004_Article_BF00218920.pd
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