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961.
962.
T. Takeda M. Fujiwara M. Kurosawa N. Takahashi M. Tamura T. Kawabata Y. Fujikawa K. N. Suzuki N. Abe T. Kubota T. Takahashi 《Journal of Radioanalytical and Nuclear Chemistry》2018,317(2):811-824
In this paper, cheap liquorice residue was used to prepare activated carbon (AC), thioacetamide (TAA) was used to modify the AC, and the adsorption experiments were conducted in the simulated acid radioactive wastewater with low uranium concentration to study the adsorption behavior and mechanism for uranium by TAA modified AC (TAA–AC). The removal efficiency by TAA–AC was 92.1–98.2% from the 1 mg L?1 uranium solution at pH 2–6. The adsorption equilibrium data were well fitted by Dubinin–Radushkevich model, and the maximum adsorption capacity was estimated to be 340 mg g?1. TAA–AC showed an enhanced selectivity for uranium in the presence of competitive ions. Furthermore, the adsorption experiments were conducted in the actual acid radioactive wastewater with low uranium concentration from an in situ leach uranium mine. The high adsorption rate (98.3%) and selectivity (Kd?=?3.78×104 mL g?1) for uranium were observed in the actual acid radioactive wastewater, and the adsorption rate was found to maintain 96.2% over six cycles of adsorption–desorption. 相似文献
963.
Tadayuki Takahashi Tatsuya Ito Seong-Yun Kim 《Journal of Radioanalytical and Nuclear Chemistry》2018,316(3):1067-1073
To separate heat-generating Cs from high-level liquid waste (HLLW), the extraction of Cs(I) using 1,3-[(2,4-diethylheptylethoxy)oxy]-2,4-crown-6-calix[4]arene (calix[4]arene-R14) in combination with 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide) ionic liquids ([C n mim][NTf2], where n?=?2, 4, and 6) was investigated. Under moderately acidic conditions, the calix[4]arene-R14/[C n mim][NTf2] system showed a higher extraction efficiency (ECs) than that exhibited by the conventional calix[4]arene-R14/dichloromethane system. All extraction processes reached equilibrium within 5 min. Slope analysis revealed that the Cs:calix[4]arene-R14 inclusion complex has a 1:1 stoichiometry. The extraction was found to be exothermic and influenced by the presence of Na(I). These extraction systems exhibited high efficiency and selectivity for Cs(I) in simulated HLLW. 相似文献
964.
Docking Strategy To Construct Thermostable,Single‐Crystalline,Hydrogen‐Bonded Organic Framework with High Surface Area 下载免费PDF全文
Dr. Ichiro Hisaki Yuto Suzuki Eduardo Gomez Dr. Boiko Cohen Dr. Norimitsu Tohnai Prof. Dr. Abderrazzak Douhal 《Angewandte Chemie (International ed. in English)》2018,57(39):12650-12655
Enhancing thermal and chemical durability and increasing surface area are two main directions for the construction and improvement of the performance of porous hydrogen‐bonded organic frameworks (HOFs). Herein, a hexaazatriphenylene (HAT) derivative that possesses six carboxyaryl groups serves as a suitable building block for the systematic construction of thermally and chemically durable HOFs with high surface area through shape‐fitted docking between the HAT cores and interpenetrated three‐dimensional network. A HAT derivative with carboxybiphenyl groups forms a stable single‐crystalline porous HOF that displays protic solvent durability, even in concentrated HCl, heat resistance up to 305 °C, and a high Brunauer–Emmett–Teller surface area [SA(BET)] of 1288 m2 g?1. A single crystal of this HOF displays anisotropic fluorescence, which suggests that it would be applicable to polarized emitters based on robust functional porous materials. 相似文献
965.
Dr. Kosuke Ono Shunsuke Shimo Dr. Kohei Takahashi Dr. Nobuhiro Yasuda Dr. Hidehiro Uekusa Prof. Nobuharu Iwasawa 《Angewandte Chemie (International ed. in English)》2018,57(12):3113-3117
Dynamic interconversion between large covalent organic cages was achieved simply by heating or acid/base treatment. A mixture of the boroxine cages 12‐mer and 15‐mer was cleanly converted into a pyridine adduct of the 9‐mer boroxine cage upon treatment with pyridine, and the geometry of N‐coordinated boron atoms changed from trigonal to tetrahedral. The reverse reaction was achieved by heating or acid treatment. In this process, the larger boroxine cages 12‐mer and 15‐mer were found to be entropically favored owing to the release of free pyridine molecules from 9‐mer ?6 Py. 相似文献
966.
Utilization of Donor–Acceptor Interactions for the Catalytic Acceleration of Nucleophilic Additions to Aromatic Carbonyl Compounds 下载免费PDF全文
Tatsuhiro Uchikura Dr. Kosuke Ono Dr. Kohei Takahashi Prof. Nobuharu Iwasawa 《Angewandte Chemie (International ed. in English)》2018,57(8):2130-2133
A conceptually new method for the catalytic electrophilic activation of aromatic carbonyl substrates, by utilizing donor–acceptor interactions between an electron‐deficient macrocyclic boronic ester host ( [2+2] BTH‐F ) and an aromatic carbonyl guest substrate, was realized. In the presence of a catalytic amount of [2+2] BTH‐F , dramatic acceleration of the nucleophilic addition of a ketene silyl acetal towards either electron‐rich aromatic aldehydes or ketones was achieved. Several control experiments confirmed that inclusion of the aromatic substrates within [2+2] BTH‐F , through efficient donor–acceptor interactions, is essential for the acceleration of the reaction. 相似文献
967.
968.
969.
A liquid jet emerging from a nozzle or an orifice whose outlet is slightly elliptic has a series of minute-amplitude waves on its surface. A quite simple technique is proposed which enables detecting such waves even if they are no longer recognizable with the aid of ordinary backlighting of the jet.This note describes a part of a study Measurements of dynamic surface tension in relation to phase-change heat transfer which was subsidized from the Ministry of Eduction, Science and Culture, Japan through Grant No. 02650167 相似文献
970.