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81.
Kanazawa N Urano K Kokado N Urushigawa Y 《Journal of colloid and interface science》2001,238(1):196-202
The adsorption of propionic acid and benzoic acid on anion-exchange resins was analyzed, and an adsorption equilibrium equation of carboxylic acids was proposed. The adsorption of carboxylic acids on the anion-exchange resins was considered to be the sum of the physical adsorption of the molecule and the ion-exchange adsorption of the ion, which were independent of each other. For the physical adsorption of carboxylic acids, it was conformed to the Freundlich equation. For the ion-exchange adsorption of carboxylate ions, the equilibrium equation corresponded well with the experimental results for wide ranges of concentration and pH. The equation contains a selectivity coefficient S(A)(Cl) for the chloride ion versus the carboxylate ion, which was considered essentially a constant. The influent of the bicarbonate ion from carbon dioxide in air could also be expressed by the additional equilibrium equation with the selectivity coefficient S(HCO(3))(Cl) for the chloride ion versus the bicarbonate ion. Consequently, an adsorption equilibrium equation can estimate the equilibrium adsorption amounts. Even the effect of a coexisting bicarbonate ion is inconsequential when the parameters of the Freundlich isotherm equation and the selectivity coefficients of the carboxylate ion and the bicarbonate ion in each resin are determined in advance. Copyright 2001 Academic Press. 相似文献
82.
Sohtome Y Kato Y Handa S Aoyama N Nagawa K Matsunaga S Shibasaki M 《Organic letters》2008,10(11):2231-2234
Stereodivergent construction of three contiguous stereocenters in catalytic doubly diastereoselective nitroaldol reactions of alpha-chiral aldehydes with nitroacetaldehyde dimethyl acetal using two types of heterobimetallic catalysts is described. A La-Li-BINOL (LLB) catalyst afforded anti,syn-nitroaldol products in >20:1-14:1 selectivity, and a Pd/La/Schiff base catalyst afforded complimentary syn,syn-nitroaldol products in 10:1-5:1 selectivity. 相似文献
83.
Nakanishi S Nagai T Fukami K Sonoda K Oka N Ihara D Nakato Y 《Langmuir : the ACS journal of surfaces and colloids》2008,24(6):2564-2568
Electrodeposition of zinc (Zn) at an aqueous ZnSO4/n-butylacetate (BuAc) interface (liquid/liquid (LL) interface) showed a potential oscillation in the region of the current density exceeding the diffusion-limited one, accompanied by formation of two-dimensional Zn film with a concentric pattern at the LL interface. In-situ optical microscopic inspections revealed that the oscillatory growth of the Zn film synchronized with meniscus oscillation of the LL interface. The vigorous growth of the deposits occurs only when the shape of the meniscus becomes hollow on the negative potential side of the potential oscillation. On the other hand, on the positive side, the meniscus becomes almost flat and the deposits formed in the preceding stage are thickened. A mechanism is proposed to explain the oscillatory Zn electrodeposition coupled with the meniscus oscillation, on the basis of the fact that the interfacial tension at the growing metal/aqueous solution interface is extremely large. 相似文献
84.
Sebastian O. Danielache Matthew S. Johnson Shinkoh Nanbu Mette M.-L. Grage Chris McLinden Naohiro Yoshida 《Chemical physics letters》2008,450(4-6):214-220
The fractionation of sulfur isotopes in the gas-phase reaction of OCS with OH was calculated by ab initio methods. The first reaction step occurs through a carbon bonded OH–OCS transition state. The activation barrier is 18.4 kJ mol−1 (CCSD(T)/aug-cc-pVDZ level plus zero-point energy) relative to the reactants. Fractionation constants are −1.4, −2.6 and −6.3‰ for 33S, 34S and 36S respectively. These results bring new insight regarding the origin of stratospheric sulfate aerosols, including the identification of characteristic isotopic fractionations in the lower and middle stratosphere. 相似文献
85.
Toyo Kaiya Naohiro Shirai Jinsaku Sakakibara Yoichi Iitaka 《Tetrahedron letters》1979,20(44):4297-4298
Reaction of grayanotoxin-II (1) with thallium nitrate gave 3(S), 20-epoxy-6 (S), 14 (R), 16 (R)-trihydroxy-5-oxo-5, 10-seco-ent-kaur-1 (10) -ene (2). The structure of 2 was elucidated by the X-ray diffraction analysis of its reduction product (3). 相似文献
86.
The adsorption behavior of alcohol vapors on acid-catalysed silica gels was investigated. The adsorption isotherms determined at two ambient temperatures were type IV or pseudo type I of BET classification, and were all interpreted by the duplicated processes of multilayer adsorption and capillary condensation. Some of the isotherms obtained gave both the monolayer capacity and the pore volume, which made it possible to calculate the mean pore radii and the fractal dimensions of the pore surfaces. The fractal dimensions obtained were close to 2, indicating the essentially smooth surface on the molecular scale. The gels prepared from the solutions containing smaller alkoxy groups were found to retain larger pore volume, which was explained in terms of the aging effect under acidic conditions. 相似文献
87.
Ikuma Kuroda Toshiharu Nagai Hoyo Mizobe Nobuhito Yoshimura Naohiro Gotoh Shun Wada 《Analytical sciences》2008,24(7):865-869
A polymeric ODS column was applied to the resolution of triacylglycerol positional isomers (TAG-PI), i.e. 1,3-dioleoyl-2-palmitoyl-glycerol (OPO) and 1,2-dioleoyl-3-palmitoyl-rac-glycerol (OOP), with a recycle HPLC system. To investigate the ODS column species and the column temperatures for the resolution of a TAG-PI pair, a mixture of OPO and OOP was subjected to an HPLC system equipped with a non-endcapped polymeric, endcapped monomeric, endcapped intermediate, or non-endcapped monomeric ODS column at three different column temperatures (40, 25, or 10 degrees C). Only the non-endcapped polymeric ODS column achieved the separation of OPO and OOP, and the lowest column temperature (10 degrees C) showed the best resolution for them. The other pair of TAG-PI, a mixture of 1,3-dipalmitoyl-2-oleoyl-glycerol (POP) and 1,2-dipalmitoyl-3-oleoyl-rac-glycerol (PPO) was also subjected to the system equipped with a non-endcapped polymeric or monomeric ODS column at five different column temperatures (40, 32, 25, 17, and 10 degrees C). Thus, POP and PPO were also separated on only the non-endcapped polymeric ODS column at 25 degrees C. However, no clear peak appeared at 10 degrees C. These results would indicate that the polymeric ODS stationary phase has an ability to recognize the structural differences between TAG-PI pairs. Also, the column temperature is a very important factor for separating the TAG-PI pair, and the optimal temperature would relate to the solubility of TAG-PI in the mobile phase. Furthermore, the recycle HPLC system provided measurements for the separation and analysis of TAG-PI pairs. 相似文献
88.
89.
Wannida Apisuk Naohiro Suzuki Hyun Joon Kim Dong Hyun Kim Boonyarach Kitiyanan Kotohiro Nomura 《Journal of polymer science. Part A, Polymer chemistry》2013,51(12):2565-2574
Aryloxo‐modified half‐titanocenes, Cp′TiCl2(O‐2,6‐iPr2C6H3) [Cp′ = Cp* ( 1 ), tBuC5H4 ( 2 )], catalyze terpolymerization of ethylene and styrene with α‐olefin (1‐hexene and 1‐decene) efficiently in the presence of cocatalyst, affording high‐molecular‐weight polymers with unimodal distributions (compositions). Efficient comonomer incorporations have been achieved by these catalysts. The content of each comonomer (α‐olefin, styrene, etc.) could be controlled by varying the comonomer concentration charged, and resonances ascribed to styrene and α‐olefin repeated insertion were negligible. The terpolymerization with p‐methylstyrene (p‐MS) in place of styrene also proceeded in the presence of [PhN(H)Me2][B(C6F5)4] and AliBu3 cocatalyst, and p‐MS was incorporated in an efficient matter, affording high‐molecular‐weight polymers with uniform molecular weight distributions. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 2565–2574 相似文献
90.