Highly stable passivation of a Si(1 1 1) surface using bilayer-GaSe

As a stable and ‘epitaxial’ passivation of a Si surface, we propose the bilayer-GaSe termination of a Si(1 1 1) surface. This surface is fabricated by depositing one monolayer of Ga on a clean Si(1 1 1) surface and subsequent annealing in a Se flux at around 520 °C, which results in unreconstructed 1×1 termination of the Si(1 1 1) surface by bilayer-GaSe. We found by scanning tunneling microscopy observation that slow cooling of the clean Si(1 1 1) surface from 850 to 520 °C with simultaneous deposition of a Ga flux results in better termination of the Si(1 1 1) surface. It was also found that this surface is stable against heating around 400 °C in O₂ atmosphere of 3×10⁻³ Pa. By utilizing these properties of the bilayer-GaSe terminated surface, we have succeeded in fabricating ZnO quantum dots on this substrate.     

Characterization of trace phenols in water by a spot-test coupled with resonance Raman spectrometry

Summary Trace phenols in aqueous solution were converted into azo dyes by reaction with a 4-sulphobenzenediazonium salt, and the dyes were characterized by means of resonance Raman spectrometry. The reaction was carried out on the spot-test scale, and several phenols at ppm-level concentrations (absolute amount several ng) could be identified. The method was successfully applied to the detection of residual agricultural chemicals, and food preservatives.

---

Identifizierung von Phenolspuren in Wasser durch eine Tüpfelreaktion in Verbindung mit Raman-Resonanz-Spektrometrie

Zusammenfassung Phenolspuren in wäßriger Lösung werden mit einem 4-Sulfobenzol-diazoniumsalz zu einem Azofarbstoff umgesetzt. Dieser wird mit Hilfe der Raman-Resonanz-Spektrometrie identifiziert. In Form einer Tüpfelreaktion lassen sich Phenole im ppm-Maßstab (absolute Menge einige ng) nachweisen. Das Verfahren hat sich bei Rückständen landwirtschaftlicher Chemikalien und Nahrungsmittel-Schutzstoffen bewährt.

---

---

Presented at ACS/CSJ Chemical Congress, Honolulu, Hawaii, April 1–6, 1979.     

Spin glasses with long-range interactions

A spin-glass model with a general form of long-range interactions is introduced. The replica method and the renormalization group theory are used and the results are explained from the viewpoint of frustration effects compared with the non- random case. The so-called mean field approximation is shown to be invalid for 3-d RKKY interaction systems.     

A synthesis of 5-amino- and 5-hydroxy-l-ethyl-1,4-dihydrio-4-oxo-3-quinolinecarboxylic acids and their derivatives

The synthesis and antimicrobial activity of 5-Hydroxy-l-ethyl-1,4-dihydrio-4-oxo-3-quinolinecarboxylic acids and their derivatives have been investigated. The 5-hydroxy-3-quinolinecarboxylic acids were prepared by thermal cyclization of 3-oxocyclohexenylaminomethylenemalonates followed by aromatiza-tion with iodine-ethanol, ethylation and hydrolysis of products. The 5-amino derivatives were prepared by several steps involving novel aromatization of isoxazole intermediates.     

Tetraethanolammonium counterions in surfactant and classical colloidal systems

Interaction forces between mica surfaces as a function of added tetraethanolammonium bromide, (EtOH)₄NBr, were determined using surface forces measurements. Critical micelle concentrations and aggregation numbers were determined for tetraethanolammonium dodecylsulfate, (EtOH)₄NDS, using surface tension and fluorescence probe-quencher measurements. The properties of the large hydrophilic counterion (EtOH)₄N⁺ are compared to those of its hydrophobic analogue Pr₄N⁺.     

Gelfand-Zetlin basis for Uq(gl(N+1)) modules

The Gelfand-Zetlin basis of U_q(gl(N+1)) modules is constructed via the lowering operator method.     

Binding and catalytic behavior of modified γ-cyclodextrins

Modified -cyclodextrins appended by an aromatic moiety show unique binding behavior, including a guest molecule together with the appended moiety in their -cyclodextrin cavities. Excimer formation, photoresponsive binding, association with -cyclodextrin and enhanced catalytic activity have been explained on this basis.     

Four-center-type photopolymerization in the crystalline state. XI. Crystal structure of p-phenylenediacrylic acid diethyl ester above the crystal transition point

The crystal structure of p-phenylenediacrylic acid diethyl ester above the transition point was determined at 70°C by x-ray diffraction. No significant differences in molecular arrangement are found between the structures of the α₂ form (above the transition point) and the α₁ form (at room temperature). Since the α₁ form is photopolymerized, it is concluded that selective dimerization in the α₂ form results not form the crystal structure of the monomer, but from the deterioration of molecular arrangement by the formation of dimer.