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11.
M. Kito N. Otsuka S. Nakamura M. Ishino Y. Matsui 《Photonics Technology Letters, IEEE》1996,8(10):1299-1301
DFB lasers operating at 1.3 /spl mu/m with gain-coupling structure show single-mode operation over a wide temperature range of -20/spl sim/85/spl deg/C and up to a high power of 130 mW. These lasers have InAsP absorptive grating, which can be formed by a substantially simplified fabrication process, involving annealing a corrugated InP substrate in an atmosphere of mixed arsine and phosphine. 相似文献
12.
FM mode locking of an LiNdP4 O12 (LNP) laser with an intracavity modulator is reported. Mode-locked optical pulses with a pulse width of 49 ps at a repetition rate of 960 MHz, corresponding toc/2L (c :light velocity,L :cavity length), have been obtained. A pulse repetition rate as high as 2.88 GHz has been achieved with a multiple mode-locking technique. 相似文献
13.
Yoshiharu Kariya Yasunori Hirata Masahisa Otsuka 《Journal of Electronic Materials》1999,28(11):1263-1269
Quad Flat Pack (QFP) Leads/Sn-3.5Ag-X (X=Bi and Cu) joint was thermally cycled between 243 K and 403 K or 273 K and 373 K,
and both metallographic examination and mechanical pull test were performed to evaluate thermal fatigue damage of the joint.
The addition of bismuth drastically degrades the thermal fatigue resistance of Sn-3.5Ag solder. On the other hand, the pull
strength of Sn-3.5Ag-Cu solder joints slightly decreased with increasing number of thermal cycles, though it still remains
higher in comparison to that for conventional Sn-37Pb or bismuth containing solder joint. The behavior observed here reflects
the isothermal fatigue properties of bulk solder, because thermal fatigue crack initiates at the surface of solder fillet
and propagates within the fillet in an early stage of fatigue damage. Furthermore, the lead phases lying at the interface
between lead-frame and bismuth containing solder joint may promote the crack propagation at the interface, resulting in the
extremely low thermal fatigue resistance of the joint. 相似文献
14.
15.
Intensity fluctuations of the longitudinal modes of a 0.8 μm AlGaAs laser were precisely measured during the occurrence of hopping between two modes. It was found from this result that mode hopping follows the stochastics of a Poisson process. The frequency of mode hopping was measured asf_{c} = [exp [-95(I/I_{th} - 1)]] times 10^{7} (Hz). whereI/I_{th} is the injection current normalized to its threshold value. Results of analog computer simulations showed that spontaneous emission worked as a triggering force for mode hopping. Results of the analysis based on the Fokker-Planck equation were compared to the experimental results, from which the root-mean-square value of the fluctuating electric field of spontaneous emission was estimated as2.3 times 10^{2) (V/m)leqlanglesim{E}_{N} leq 3.2 times 10^{2} (V/m). It is concluded that an effective reduction of mode hopping is achieved if the laser is operated at a higher bias or if the coupling constant between the two modes is increased. 相似文献
16.
Kiyomi Ohmori Asuka Kamei Yuki Watanabe Keiko Abe 《International journal of molecular sciences》2022,23(6)
The Bhas 42 cell transformation assay (Bhas 42 CTA) is the first Organization for Economic Cooperation and Development (OECD)-certificated method used as a specific tool for the detection of the cell-transformation potential of tumor-promoting compounds, including non-genotoxic carcinogens (NGTxCs), as separate from genotoxic carcinogens. This assay offers the great advantage of enabling the phenotypic detection of oncotransformation. A key benefit of using the Bhas 42 CTA in the study of the cell-transformation mechanisms of tumor-promoting compounds, including non-genotoxic carcinogens, is that the cell-transformation potential of the chemical can be detected directly without treatment with a tumor-initiating compound since Bhas 42 cell line was established by transfecting the v-Ha-ras gene into a mouse fibroblast cloned cell line. Here, we analyzed the gene expression over time, using DNA microarrays, in Bhas 42 cells treated with the tumor-promoting compound 12-O-tetradecanoylphorbol-13-acetate (TPA), and NGTxC, with a total of three repeat experiments. This is the first paper to report on gene expression over time during the process of cell transformation with only a tumor-promoting compound. Pathways that were activated or inactivated during the process of cell transformation in the Bhas 42 cells treated with TPA were related not only directly to RAS but also to various pathways in the hallmarks of cancer. 相似文献
17.
Toshiki Ueno Takeru Nakaki Taisei Mukogawa Shuonan Dong Hiroki Kurita Keisuke Otsuka Kanjuro Makihara Fumio Narita 《Advanced Engineering Materials》2023,25(19):2300185
In this study, the Fe–Co alloy is combined with cobalt ferrite (CoFe2O4) and nickel (Ni) to form Fe–Co/CoFe2O4 and Fe–Co/Ni clad sheets and their energy-harvesting performance is evaluated. The Fe–Co/CoFe2O4 clad sheet exhibits an output voltage of 4.229 mV and an output power of 6.89 nW at a wind speed of 10 m s−1. The energy-harvesting performance of both these clad sheets cannot be quantitatively compared owing to their different thicknesses, which result in varying volume and distance from the neutral plane. Nevertheless, the values of output voltage and power for Fe–Co/CoFe2O4 are higher than those for Fe–Co/Ni (2.107 mV and 0.294 nW). 相似文献
18.
Otsuka H Hirano A Nagasaki Y Okano T Horiike Y Kataoka K 《Chembiochem : a European journal of chemical biology》2004,5(6):850-855
A two-dimensional microarray of ten thousand (100 x 100) hepatocyte heterospheroids, underlaid with endothelial cells, was successfully constructed with 100 microm spacing in an active area of 20 x 20 mm on microfabricated glass substrates that were coated with poly(ethylene glycol) brushes. Cocultivation of hepatocytes with endothelial cells was essential to stabilize hepatocyte viability and liver-specific functions, allowing us to obtain hepatocyte spheroids with a diameter of 100 microm, functioning as a miniaturized liver to secret albumin for at least one month. The most important feature of this study is that these substrates are defined to provide an unprecedented control of substrate properties for modulating cell behavior, employing both surface engineering and synthetic polymer chemistry. The spheroid array constructed here is highly useful as a platform of tissue and cell-based biosensors and detects a wide variety of clinically, pharmacologically, and toxicologically active compounds through a cellular physiological response. 相似文献
19.
Fischer–Tropsch synthesis was carried out in slurry phase over uniformly dispersed Co–SiO2 catalysts prepared by the sol–gel method. When 0.01–1 wt.% of noble metals were added to the Co–SiO2 catalysts, a high and stable catalytic activity was obtained over 60 h of the reaction at 503 K and 1 MPa. The addition of noble metals increased the reducibility of surface Co on the catalysts, without changing the particle size of Co metal significantly. High dispersion of metallic Co species stabilized on SiO2 was responsible for stable activity. The uniform pore size of the catalysts was enlarged by varying the preparation conditions and by adding organic compounds such as N,N-dimethylformamide and formamide. Increased pore size resulted in decrease in CO conversion and selectivity for CO2, a byproduct, and an increase in the olefin/paraffin ratio of the products. By modifying the surface of wide pore silica with Co–SiO2 prepared by the sol–gel method, a bimodal pore structured catalyst was prepared. The bimodal catalyst showed high catalytic performance with reducing the amount of the expensive sol–gel Co–SiO2. 相似文献
20.
Yoshitake Masuda Kazumi Kato Masahito Kida Jun Otsuka 《International Journal of Applied Ceramic Technology》2019,16(5):1807-1811
SnO2 nanosheets were developed to detect nonanal gas in the order of ppb which was a marker of lung cancer. The nanosheets showed higher resistance change in nonanal gas than that in carbon monoxide (CO), nitrogen dioxide (NO2), acetone (CH3COCH3), hydrogen (H2), ethanol (C2H6O), ammonia (NH3), hydrogen sulfide (H2S), formaldehyde (HCHO), acetaldehyde (CH3CHO), or butanal (C4H8O). Crystal surfaces of the nanosheets would be effective for adsorption of nonanal molecules. Furthermore, it was shown that resistance changed with an increase in carbon number in aldehyde. The nanosheets had molecular selectivity for a series of aldehyde molecules. Molecular recognition of the nanosheets gave us a great advantage to detect nonanal gas which was produced by lung cancer. 相似文献