连续波锁模P_r~（3＋）：YLF激光器

本文报导了采用氩离子激光器来泵浦Ｒｒ￣（３＋）：ＹＬＦ晶体，应用声光调制器实现了主动锁模；同时应用振动─高反射平面镜也实现了被动锁模，两种锁模均得到了ｐｓ光脉冲。据作者了解这是这种晶体材料的第一次锁模运转。     

Reaction of hydrogen atoms and O2(1Δg)

The reaction of atomic hydrogen with O₂(¹Δ_g) has been investigated as a function of temperature, using a fast discharge-flow apparatus equipped for EPR detection of free radical species. The rate constant for the overall reaction was measured as (1.46 ± 0.49) × 10^?11 exp(-4000 ± 200 cal/mol/RT) cm³/s. Evidence is presented which suggests that the reaction occurs principally via abstraction, H + O₂(¹Δ_g) → OH + O, rather than via physical quenching, H + O₂(¹Δ_g) → H + O₂(X³Σ_g^?).     

Derivate des 1,3-Dioxolan-4-ons und des 1,3-Oxathiolan-5-ons

Zusammenfassung Es wird die Synthese einer Anzahl von 1,3-Dioxolan-4-onen und 1,3-Oxathiolan-5-onen beschrieben und über eine pharmakologische Prüfung dieser Substanzen berichtet.Herrn Prof. Dr.J. W. Breitenbach mit den besten Wünschen zum 60. Geburtstag gewidmet.     

Intelligent drug delivery systems obtained by radiation

Radiation-induced polymerization of acryloyl-L-proline methyl ester, an -aminoacid-containing monomer, in the presence of a crosslinking agent and a hydrophilic monomer gave rise to polymer hydrogels whose water content at equilibrium was found to decrease as the swelling temperature increased. Some hydrogel samples were obtained with entrapped acetaminophen, an analgesic and antipyretic drug. It was ascertained that the release of the drug was controlled by both the hydrophilicity of the polymer matrices and the environmental temperature.     

Mechanochemical Transformations in the Zinc-Magnetite System

Mixtures of magnetite and zinc powders were milled for up to 540 minutes and the development of the system was followed using X-ray diffraction, Mössbauer spectroscopy, and magnetic measurements. The process takes place in two overlapping steps. During the first hour of milling, a nonmagnetic intermediate mixed oxide phase forms which decomposes into ZnO and Fe upon further milling. The freshly formed iron particles are supersaturated with Zn.     

A removable auxiliary for amidomercuration reactions: The stereoselective preparation of substituted n-acyl pyrrolidines and piperidines

Salicylamide condenses with γ,δ- or δ,-unsaturated aldehydes to give cyclic amidals which readily undergo diastereoselective mercury(II)-mediated amidocyclization. The resulting products serve as versatile intermediates for further elaboration as nitrogen heterocycles.     

The mechanochemical reduction of AgCl with metals

Faraday induced the mechanochemical reduction of AgCl with Zn, Sn, Fe and Cu in 1820, using trituration in a mortar. This experiment is revisited, employing a mortar-and-pestle and a ball mill as mechanochemical reactors. The reaction kinetics depends both on the thermochemical properties and the hardness of the reactants. When using Zn as the reducing agent, Faraday likely observed a mechanically induced self-sustaining process (MSR), or at least he came very close to doing so.     

Regio- and diastereoselective boron-mediated aldol reactions of chiral α,β,γ,δ-unsaturated N-acyloxazolidinones

Chiral N-acyloxazolidinones derived from conjugated dienoic acids undergo boron-mediated aldol condensation in good yield and with high regio- and diastereoselectivity to provide a convenient method for introducing a 1,3-diene subunit. The condensation of a homologous triene derivative is also described.