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1.
Incombustible electromagnetic wave absorbing material made of incombustible ceramic fibers are proposed in this paper. The hollow-type pyramids were experimentally fabricated by means of a nonwoven fabric production process and their flammability and electromagnetic wave absorption were investigated. By the tests using high-power microwaves and gas burner flames, it was confirmed that the material shows extremely good flame retardance. Also, it was confirmed that pyramids made of this material had good electromagnetic wave absorption characteristics. The pyramids made of this material are able to be used as absorbers for anechoic rooms instead of conventional plastic pyramids such as urethane foam or polystyrene pyramids, which are combustible 相似文献
2.
Spot-size converter integrated semiconductor optical amplifiers foroptical gate applications 总被引:1,自引:0,他引:1
Kitamura S. Hatakeyama H. Hamamoto K. Sasaki T. Komatsu K. Yamaguchi M. 《Quantum Electronics, IEEE Journal of》1999,35(7):1067-1074
A spot-size converter integrated semiconductor optical amplifier (SSC-SOA) was developed as a gate element in an optical switch matrix for photonic switching applications. By a selective metal-organic vapor phase epitaxy technique, a bulk InGaAsP stripe, including an active region and thickness tapered SSCs, was grown. Wavelength composition of the stripe, strain on the stripe, and electrode coverage above the SSC region were optimized. As a result, gate operation for fiber-to-fiber gain of 0 dB was achieved at a low injection current of 30 mA, and the polarization dependence of the gain was eliminated as well 相似文献
3.
Yashiki K. Kudo K. Morimoto T. Sudo S. Muroya Y. Tamanuki T. Ishizaka M. Hosoda T. Furushima Y. Hatakeyama H. Yokoyama Y. Mori K. Sasaki T. Yamaguchi M. 《Photonics Technology Letters, IEEE》2002,14(2):137-139
In this letter, we have simultaneously fabricated five wavelength-selectable microarray light sources (WSLs), each having a different wavelength range integrated with an electroabsorption (EA) modulator on a single wafer. We also introduced a novel device configuration scheme for wavelength-independent modulation. The five EA-WSLs fully covered the entire C-band and had a low uniform threshold current of 6 ± 1 mA at 25°C. Wavelength-independent extinction characteristics were obtained over a tuning wavelength range of 8 nm, and 2.5-Gb/s transmission over 600 km was successfully achieved 相似文献
4.
The so-called Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state is a possible inhomogeneous superfluid phase in population-imbalanced two-component Fermi gas systems. Here, a novel phase created by a population-imbalance to be called a Fermion supersolid will be proposed. In a Fermi gas with a short-ranged repulsive interaction, a positional order, corresponding to the antiferromagnetic (AFM) one in the electronic systems, may occur, although the ordinary superfluid phase usually suppresses it in population-balanced two component Fermi systems. However, we show that the coexistence between this “AFM” order and the FFLO superfluid with s-wave pairing is rather favored by the population-imbalance. This coexisting phase is the s-wave analog of the coupled AFM and FFLO orders detected in the d-wave paired superconductor CeCoIn5. 相似文献
5.
Primbs T Simonich S Schmedding D Wilson G Jaffe D Takami A Kato S Hatakeyama S Kajii Y 《Environmental science & technology》2007,41(10):3551-3558
To estimate the emissions of anthropogenic semivolatile organic compounds (SOCs) from East Asia and to identify unique SOC molecular markers in Asian air masses, high-volume air samples were collected on the island of Okinawa, Japan between 22 March and 2 May 2004. Contributions from different source regions (China, Japan, the Koreas, Russia, and ocean/local) were estimated by use of source region impact factors (SRIFs). Elevated concentrations of hexachlorobenzene (HCB), hexachlorcyclohexanes (HCHs), dichlorodiphenyltrichloroethanes (DDTs), and particulate-phase polycyclic aromatic hydrocarbons (PAHs) were attributed to air masses from China. A large proportion of the variation in the current-use pesticides, gas-phase PAHs, and polychlorinated biphenyl (PCB) concentrations was explained by meteorology. Chlordanes showed a technical mixture profile and similar concentrations regardless of source region. alpha/gamma HCH and trans/cis chlordane ratios did not vary significantly with different source regions and had regional averages of 2.5 +/- 1.0 and 1.2 +/- 0.3, respectively. Particulate-phase PAH concentrations were significantly correlated (p value < 0.05) with other incomplete combustion byproduct concentrations, including elemental mercury (Hg0), CO, NOx, black carbon, submicrometer aerosols, and SO2. By use of measured PAH, CO, and black carbon concentrations and estimated CO and black carbon emission inventories, the emission of six carcinogenic particulate-phase PAHs was estimated to be 1518-4179 metric tons/year for Asia and 778-1728 metric tons/year for China, respectively. These results confirm that East Asian outflow contains significant emissions of carcinogenic particulate-phase PAHs. 相似文献
6.
This paper is concerned with the structural identification of linear multivariable systems and an interactive identification package. The structural identification is done by taking the time-invariant subsystem from the realizations of the input-output relations identified using data of disjoint time intervals, and the statistical hypothesis test is employed to determine the order, where the input-output relation is identified based on the generalized least squares method using the possibly larger model for the plant. The identification package is for the identification of the input-output relation of a linear multivariable system, for the structural identification based on the realization and for data management. 相似文献
7.
Hatakeyama E Kajita H Sugawara T Sasaki A Takahashi S Komukai T 《Shokuhin eiseigaku zasshi. Journal of the Food Hygienic Society of Japan》2006,47(4):137-145
A method for simultaneous determination of multiple pesticide residues in agricultural products was developed by using a pretreatment with ultrafiltration, followed by liquid chromatography-tandem mass spectrometry (LC/MS/MS). The pretreatment process (extraction of pesticides from agricultural products with methanol, dilution of the extract with water, and ultrafiltration) gave recoveries in the range of 50-150% for 63 of 83 pesticides spiked at 0.25 microg/ g into 6 agricultural products. The detection limits of pesticides by LC/MS/MS were below 0.0005-0.05 micro/g. This method is useful for screening purposes and for multiresidue analysis of pesticides in agricultural products. Pesticide residues in 50 domestic crops were investigated by this method, and residues of 14 pesticides were detected in 30 crops. 相似文献
8.
Monodispersed spherical β-SiC powder was synthesized by heating spherical gel powder derived from the hydrolysis of a mixture of phenyltriethoxysilane and tetraethyl orthosilicate. The solution was prepared in a beaker and hydrolyzed by NH4 OH without stirring. The monodispersed spherical gel powder of submicrometer size was obtained when the added amount of NH4 OH was greater than 16 moles per mole of silane plus alkoxide, and it became monodispersed spherical β-SiC powder by heat-treating at 1500°C for 4 h in an Ar atmosphere. The SiC content of the powder was 92.6 wt%. 相似文献
9.
Rejina Shrestha Naoko Murata-Kamiya Satoshi Imai Masami Yamamoto Tetsuya Tsukamoto Sachiyo Nomura Masanori Hatakeyama 《International journal of molecular sciences》2022,23(5)
The initial step in bacterial infection is adherence of the bacterium to the target cell surface. Helicobacter pylori exploits the interaction of bacterial adhesin protein HopQ with human epithelial CEACAMs (CEACAM1, 5, and 6) to stably adhere to gastric epithelial cells, which is necessary for delivery of the H. pylori CagA oncoprotein into the epithelial cells via a type IV secretion system. In contrast to human CEACAMs, however, HopQ does not interact with Ceacam1 (mouse CEACAM1) in vitro or in CHO cells ectopically expressing Ceacam1. Since the mouse genome lacks Ceacam5 and Ceacam6, no significant HopQ–Ceacam interaction may occur in mouse gastric epithelial cells. Here, we found that the mouse stomach has a much lower expression level of Ceacam1 than the expression level of CEACAM1 in the human stomach. Consistently, mouse gastric epithelial cells resist CagA delivery by cagA-positive H. pylori, and the delivery is restored by ectopic expression of human CEACAM1 or CEACAM5 in mouse gastric epithelial cells. Thus, despite the fact that mice are routinely used for H. pylori infection studies, a low expression level of Ceacam1 in the mouse stomach together with the loss or greatly reduced interaction of HopQ with Ceacams make the mouse an inappropriate model for studying the role of H. pylori-delivered CagA in gastric pathogenesis, including the development of gastric cancer. 相似文献
10.