著者

瀬川 泰知 長瀬 真依 齋藤 雄太朗 加藤 健太 伊丹 健一郎

出版者

The Society of Synthetic Organic Chemistry, Japan

雑誌

有機合成化学協会誌 (ISSN:00379980)

巻号頁・発行日

vol.80, no.11, pp.994-999, 2022-11-01 (Released:2022-11-05)

参考文献数

42

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The selective and predictable C-H functionalization of arenes is a valuable method for the synthesis and modification of organic molecules in which regioisomer formation is often controlled by electronic factors or the presence of coordinating groups. On the other hand, the iridium-catalyzed C-H borylation of arenes can achieve unique steric-controlled regioselectivity. In this account, we describe our recent studies on the iridium-catalyzed C-H borylation of arenes: the development of novel catalytic systems that exhibit steric-controlled para-selectivity for mono- and unsymmetrically 1,2-disubstituted benzenes; and their application to the functionalization of large polycyclic aromatic hydrocarbons (molecular nanocarbons).

著者

齋藤 雄太 鶴岡 慶雅

雑誌

ゲームプログラミングワークショップ2016論文集

巻号頁・発行日

vol.2016, pp.196-200, 2016-10-28

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事前知識を用いない多人数不完全情報ゲームのAIの学習は、人工知能を現実世界の問題に応用する上で非常に重要な課題の一つである。本研究では、多人数不完全情報ゲームの一種であるトリックテイキングゲームの行動価値観数を線形関数で近似し、Q学習を行った。その結果、トリックテイキングゲームにQ学習を適用することで単純なルールベースのプレイヤに勝る結果が得られること、自己対戦による学習を行うことで、ランダムプレイヤによる学習を行った時よりも学習結果が向上することを示した。

著者

谷地畝 和夫 鈴木 彰 齋藤 雄太 得能 将紀 小林 正人

出版者

日本建築学会

雑誌

日本建築学会構造系論文集 (ISSN:13404202)

巻号頁・発行日

vol.86, no.781, pp.381-391, 2021 (Released:2021-03-30)

参考文献数

17

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In recent years, there is concern about the occurrence of extreme ground motions that greatly exceed the amplitude levels and durations expected in conventional design level. Therefore, seismically isolated buildings are required to secure the seismic isolation performance for small earthquakes and to suppress the excessive displacement of the seismic isolation layer for extreme ground motions. As one of the effective means to meet the above requirements, in addition to an electromagnetic switching semi-active seismic isolation system, a cheaper and more reliable passive damper is being developed. Meanwhile, the authors have proposed a dead zone mechanism that is an accessory device connected to the existing oil damper. When the relative displacement of seismic isolation layer is smaller than the set amplitude (medium and small earthquakes level), the dead zone mechanism only slides and no damping force is generated in the oil damper, and when the amplitude is larger than the set amplitude (extreme ground motions), this mechanism generates damping force and suppresses excessive displacement. Furthermore, one of the features of this mechanism is that it has a mechanism that automatically returns the rod to the original position after the earthquake. In this paper, we analyze the seismic response of seismically isolated buildings using the dead zone mechanism to understand the response characteristics.  1) When the publicly announced wave and pulse ground motions are used as input earthquakes, an oil damper with a dead zone mechanism is used in the seismic isolation building to ensure seismic isolation performance for small and medium earthquakes, while suppressing excessive displacement of the seismic isolation layer for extreme ground motions. It was confirmed that the desires effect of doing was obtained. In this analysis case, the most effective performance was shown when the dead zone width was set to 15cm. 2) When the long period ground motions is used as the input ground motions, the acceleration response of the GAP model is larger than that of the OD model, but the acceleration is small at about 100~200cm/s2, which is considered to be within the allowable range for seismic isolation. 3) It was confirmed that the automatic return spring in the dead zone mechanism automatically returns the rod in the mechanism to the neutral position at the end of the earthquake. Therefore, by automatically returning the dead zone mechanism to the automatic return spring in the dead zone mechanism, it is possible to maintain the structural performance assumed at the time of design even when multiple earthquakes occur in a short period of time. 4) In all earthquakes, when the seismic isolation layer displacement reaches the dead zone width, the absolute acceleration increase in the lower layer. The cause is considered to be a reaction force due to the elements of the dead zone mechanism contacting each other. The 1/3 octave band analysis was applied to the time history waveform of the absolute response acceleration above the seismic isolation layer of each model. It was confirmed that the value was sufficiently smaller than the judgment value of the rank with the lowest anxiety level, compared with the evaluation curve in the anxiety level evaluation by Takahashi et al. Therefore, it was confirmed that the increase in acceleration response when the elements in the dead zone mechanism were in contact had little effect on the habitability.

著者

佐藤 千佳 辻 まゆみ 木村 謙吾 小口 勝司 中西 孝子 舟橋 久幸 齋藤 雄太 植田 俊彦 小出 良平

出版者

昭和大学学士会

雑誌

昭和学士会雑誌 (ISSN:2187719X)

巻号頁・発行日

vol.75, no.4, pp.450-457, 2015 (Released:2016-01-23)

参考文献数

30

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生直後から12日齢まで80%酸素にて飼育した未熟児網膜症モデルラットと以前,報告された高酸素負荷による酸化ストレス誘発性脳障害モデルと比較し,未熟児網膜症モデルの酸化ストレス誘発性脳障害モデルとしての有効性について検討した.出生直後より12日齢まで80%高酸素負荷ラット(P12)およびその後大気中に移動し24時間飼育したラット(P13)は,脳(海馬)を摘出した.海馬の凍結切片を作製し,DNA酸化損傷マーカーである8-hydroxy-2'-deoxyguanosine(8-OHdG)を免疫染色し,局在を確認した.また,ホモジェネートを作製し,酸化ストレスマーカーであるreactive oxygen species(ROS),脂質過酸化物(malondialdehyde: MDA),酸化型グルタチオン(GSSG)量を,RT-PCR法によりO2-を酸素と過酸化水素へ不均化する酸化還元酵素Cu/Znsuperoxidedismutase(SOD)mRNAを測定し,記憶や学習に関わる海馬への酸化ストレスを確認した.さらに,ROSを積極的に産生する酵素type 4 nicotinamide adenine dinucleotide phosphate(NADPH)oxidase(Nox4)mRNAを測定し,Nox4の役割について考察した.8-OHdGはコントロール群に比べて,高酸素負荷終了直後(P12)増加していた.特に,CA1,CA3,歯状回(DG)では8-OHdG陽性細胞数の増加は顕著だった.P12海馬内ROS,Cu/Zn SOD mRNA,GSSG,MDA量は高酸素負荷群でコントロール群に比べ有意に増加しており,P13でも同様の結果を示した.P12での海馬内酸化ストレスの結果はこれまでの報告と一致していた.海馬Nox4 mRNAはコントロールに比べP13の酸素負荷群で2.7倍となり,相対的低酸素状態(脳虚血)から低酸素状態への適応(再灌流)による神経変性を増悪する可能性が示唆された.ラット脳,網膜などの神経組織が成熟する生後12日(P12)まで高酸素投与を継続する未熟児網膜症モデルは本研究により初めて酸化ストレス誘発性脳障害モデルとしても応用可能であることが示された.