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91.
Summary The potential ranges of polarization of a pair of dropping mercury electrodes, over which the two mercury droplets coalesced, were measured as functions of ionic concentrations for various electrolytes. In the case of simple inorganic electrolytes the condition of coalescence obtained was proved to be in quantitative agreement with theVerwey-Overbeek theory of coagulation of lyophobic sols, thus indicating that the interaction between sub-microscopic particles of hydrophobic sols is essentially the same as that between macroscopic mercury droplets. While, in the case of sodium citrate solutions two kinds of marked deviations from the theory were observed, which appeared to be due to the specific adsorption of citrate ions and to the formation of protective interfacial films.
Zusammenfassung Die Potentialbereiche der Polariation eines Paares von Quecksilber-Tropfelektroden, über die die beiden Quecksilbertropfen koaleszieren, werden als Funktion der Ionenkonzentration verschiedener Elektrolyte gemessen. Im Fall einfacher anorganischer Elektrolyte wurde die erhaltene Bedingung der Koaleszenz mit der Theorie vonVerwey-Overbeek der Kaogulation lyophober Sole geprüft und in quantitativer übereinstimmung befunden. Das zeigt, da\ die Wechselwirkung zwischen submikroskopischen Partikeln hydrophober Sole im wesentlichen dieselbe ist wie zwischen den makroskopischen Quecksilbertröpfchen. Dagegen ergaben sich im Fall von Natriumzitratlösungen zwei Arten markanter Abweichungen von der Theorie. Diese scheinen spezifische Adsorption der Zitrationen und die Ausbildung von SchutzgrenzflÄchenfilmen zur Ursache zu haben.相似文献
92.
Tsutomu Kagiya Masatsugu Izu Masakazu Hatta Takehisa Matsuda Kenichi Fukui 《Journal of polymer science. Part A, Polymer chemistry》1967,5(5):1129-1135
N,N′-Dipropionylethylenediamine was synthesized by the ring-opening addition reaction of 2-ethyl-2-imidazoline with propionic acid at 220°C. By applying this reaction to polymerization, polyamides were synthesized by the ring-opening polyaddition reaction at 220°C. of 1,4-bis(imidazoline-2-yl)butane with adipic acid, succinic acid, sebacic acid, and terephthalic acid. The reaction product of 1,4-bis(imidazoline-2-yl)butane with adipic acid, which was proposed to be nylon 26, was compared with an authentic sample of nylon 26 and shown to possess a very similar infrared spectrum and melting point. 相似文献
93.
Qi ZM Matsuda N Santos J Yoshida T Takatsu A Kato K 《Journal of colloid and interface science》2004,271(1):249-253
Broadband, time-resolved optical waveguide (OWG) spectroscopy has been used for in situ, real-time investigation into the self-assembly of metal nanoparticle monolayers. The OWG spectroscopy makes it possible to use the transverse electric (TE) and transverse magnetic (TM) modes to measure surface plasmon absorption of immobilized metal nanoparticles in two directions, parallel and normal to the waveguide surface. Therefore, this technique can provide direction-dependent information on the metal nanoparticles at the interface. In this paper, a 50-microm-thick glass plate was used as a slab waveguide and the kinetics of Au nanoparticle adsorption on a hemoglobin-functionalized glass substrate was examined in the early stage of self-assembly. The findings show that with the TE mode the surface plasmon resonance (SPR) behavior for immobilized Au nanoparticles is different from that with the TM mode. 相似文献
94.
95.
The theory of first-order kinetic collection efficiencies at the double channel electrode is developed for the following two schemes: (I) A±n1e→B (at the generator electrode), B→kP (in solution), B±n2e→Y (at the detector electrode), (II) A±n1e→B, B→kA, B±n2e→Y. The exact expressions for the kinetic collection efficiencies are obtained as ascending and asymptotic series with respect to the kinetic parameter. Further, approximate formulae in exponential forms are given, which hold within an error of about 2% for conventional electrode geometry. Finally, the validity of the approximate procedure, which has been used previously to obtain the kinetic collection efficiencies for fast homogeneous reactions, is discussed in comparison with the present theory. 相似文献
96.
A porphyrin nanotube: size-selective inclusion of tetranuclear molybdenum-oxo clusters 总被引:2,自引:0,他引:2
Harada R Matsuda Y Okawa H Kojima T 《Angewandte Chemie (International ed. in English)》2004,43(14):1825-1828
97.
Akiko Saito Mana Emoto Akira Tanaka Yuki Doi Kazuaki Shoji Yoshiyuki Mizushina Hiroshi Ikawa Hiromi Yoshida Nobuyasu Matsuura Noriyuki Nakajima 《Tetrahedron》2004,60(52):12043-12049
A simple method for the synthesis of procyanidin B3 substituted with a galloyl group at the 3 and 3″ position is described. Condensation of a benzylated catechin-3-O-gallate electrophile with a nucleophile, catechin and catechin-3-O-gallate, proceeded smoothly and stereoselectively to afford the corresponding dimer gallates, procyanidin B3-3-O-gallate and procyanidin B3-3,3″-di-O-gallate, in good yields. Further, their antioxidant activities on UV-induced lipid peroxide formation, DPPH radical scavenging activity and inhibitory activity of DNA polymerase were also investigated. Among three procyanidin B3 congeners (procyanidin B3, 3-O-gallate and 3,3″-di-O-gallate), the 3,3″-di-O-gallate derivative showed the strongest antioxidant and radical scavenging activity. Interestingly, the 3-O-gallate derivative was the strongest inhibitor of mammalian DNA polymerase with IC50 value of 0.26 μM, although it showed the weakest antioxidant and radical scavenging activity. It became apparent that the presence of a galloyl group at the C-3 position in the proanthocyanidin oligomer was very important for biological activity, however, the antioxidant activity of these compounds was not parallel to the DNA polymerase inhibitory activity. 相似文献
98.
Combinatorial library of isoxazoles was prepared by 1,3-dipolar cycloaddition on solid support. p-Cyano derivatives showed nematic and/or smectic A phases. A bilayer smectic phase for 2h is proposed by the combination of molecular mechanics calculation and X-ray diffraction experiment. 相似文献
99.
Hiroshi Sakurai Akira Tatematsu Hisao Nakata 《Journal of mass spectrometry : JMS》1973,7(9):1109-1110
A novel rearrangement reaction for a methyl group is found in doubly charged ion mass spectra of p-substituted acetophenone derivatives. The driving force for the reaction is discussed. 相似文献
100.
Akira Ando 《Journal of fluorine chemistry》2005,126(5):765-770
Treatment of 2-chloro-3,3-difluoroprop-2-en-1-ol derivatives (2) with methanesulfonyl chloride in the presence of a base did not give the expected esters but 2-chloro-1,1-difluoroprop-2-enyl methanesulfonates (4) through a novel [3,3] sigmatropic rearrangement. Reaction of 4 with diethylzinc in the presence of tetrakis(triphenylphosphine) palladium gave 1-alkyl- or 1-aryl-2-chloro-3-fluoropenta-1,3-dienes in moderate to good yields through a CC bond formation followed by dehydrofluorination. 相似文献